Home | About us | Editorial board | Search | Ahead of print | Current Issue | Archives | Instructions | Subscribe | Advertise | Contact us |  Login 
Pharmacognosy Reviews
Search Article 
  
Advanced search 
 


 
 Table of Contents  
REVIEW ARTICLE
Year : 2018  |  Volume : 12  |  Issue : 23  |  Page : 85-93  

Antimicrobial and anticancer potential of Petiveria alliacea L. (Herb to “Tame the Master”): A review


1 Neuroscience and Cell Biology Graduate Program, Federal University of Pará, Belém, Pará, Brazil
2 Pharmaceutical Sciences Graduate Program, Federal University of Pará, Belém, Pará, Brazil
3 Faculty of Pharmacy, Federal University of Amapá, Macapá, Amapá, Brazil
4 Pharmaceutical Innovation Graduate Program, Federal University of Pará, Belém, Pará, Brazil
5 Neuroscience and Cell Biology Graduate Program, Federal University of Pará; Faculty of Pharmacy, Federal University of Pará, Belém, Pará, Brazil
6 Pharmaceutical Sciences Graduate Program, Federal University of Pará; Faculty of Pharmacy, Federal University of Pará, Belém, Pará, Brazil

Date of Web Publication10-May-2018

Correspondence Address:
Prof. Marcieni Ataíde de Andrade
Pharmaceutical Sciences Graduate Program, Institute of Health Sciences, Federal University of Pará, Rua Augusto Corrêa, 01, Guamá, Belém, PA
Brazil
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/phrev.phrev_50_17

Rights and Permissions
   Abstract 


Petiveria alliacea is a perennial Amazonian shrub used in traditional medicine for many purposes worldwide, including as antirheumatic, antispasmodic, antifungal, and analgesic for pain relief. Herein, this review aimed to provide a concise overview of the phytochemistry and antimicrobial, anticancer, and immunomodulatory properties reported in the literature for P. alliacea. The herb is rich in sulfur-containing compounds that possess a broad-spectrum of in vitro antimicrobial activity against pathogenic fungi and bacteria at low concentrations. P. alliacea also showed cytotoxicity and antiproliferative activity against cancer cell lines through sophisticated machinery of cellular damage in vitro. Other compounds such as flavonoids, terpenoids, and benzenoids are commonly identified in P. alliacea extracts, and they may also justify these activities. Despite the great pharmacological potential, clinical trials are required to ensure its effectiveness and safety. This review may raise new trends on the studies as well as contribute to the community by offering data for decision-making with regard to its use in treating diseases.

Keywords: Anticancer activity, antimicrobial activity, cytotoxicity, Petiveria alliacea, sulphur-containing compounds


How to cite this article:
Silva JP, do Nascimento SC, Okabe DH, Pinto AC, de Oliveira FR, da Paixão TP, Siqueira ML, Baetas AC, de Andrade MA. Antimicrobial and anticancer potential of Petiveria alliacea L. (Herb to “Tame the Master”): A review. Phcog Rev 2018;12:85-93

How to cite this URL:
Silva JP, do Nascimento SC, Okabe DH, Pinto AC, de Oliveira FR, da Paixão TP, Siqueira ML, Baetas AC, de Andrade MA. Antimicrobial and anticancer potential of Petiveria alliacea L. (Herb to “Tame the Master”): A review. Phcog Rev [serial online] 2018 [cited 2019 Aug 25];12:85-93. Available from: http://www.phcogrev.com/text.asp?2018/12/23/85/232203




   Introduction Top


Petiveria alliacea L. (Phytolaccaceae) is a wild and perennial shrub that grows throughout tropical areas in South and Central America, Caribbean, and Africa.[1] The herb was first identified by Carl Von Linnaeus and published in his book Species Plantarum.[2] The genus name of this herb is derived from Jacob Petiver, who dedicated his work to medicinal plant study, while the epithet is related to the pungent smell of garlic released after tissue disruption.[3]

In the 17th century, African slaves used to use preparations obtained from P. alliacea to make their masters lethargic, and for this reason, P. alliacea is widely known in Brazil as the herb to “tame the master.”[1],[3],[4] The plant is also called mucuracaá, tipi, guiné, pipi, apacin, herbe aux Poules, anamu, and embayayendo.[5] Nowadays, herbal medicines derived from P. alliacea are available on the market in Paraguay, Cuba, and Japan.[4],[6]

P. alliacea has been used in traditional medicine with different purposes in many countries, such as antirheumatic, analgesic, and to treat respiratory conditions.[7],[8],[9],[10],[11] Pharmacological investigations have highlighted the therapeutic potential of P. alliacea as an immunomodulator, analgesic, antimicrobial, and anticancer.[12],[13],[14],[15],[16],[17],[18] A large number of papers of P. alliacea published in the last decades has motivated our group to gather these data to allow a concise overview for the scientific community. Hence, this paper provides a critical review on phytochemistry and pharmacology of P. alliacea, regarding its antimicrobial, anticancer and immunomodulatory activities.


   Botanical Considerations Top


P. alliacea is a perennial subshrub, sub Woody, erect, and branched with long branches, which are delicate and ascending, measuring up to 1 m in height. The leaves are 5–10 cm long and 2–6 cm in width, discolor, oblong-lanceolate, acuminate, with a cuneiform base and short petioles, its texture ranges from membranaceous to herbaceous, with prominent midrib in the abaxial face and secondary arqued veins.[19]

P. alliacea roots are pivoting type and may reach 30 cm in length and 1 cm in diameter in the base; it has a yellowish–brown surface, tortuous, pale externally, and bright whiteness internally, with an acre flavor and a garlic-like odor.[20]

The botanical synonymies are P. alliacea var. grandiflora Moq., P. alliacea var. octandra (L.) Moq., Petiveria corrientina Rojas, Petiveria foetida Salisb., Petiveria hexandria Sessé and Moc., Petiveria ochroleuca Moq., Petiveria octandra L., Petiveria paraguayensis D. Parodi.[21]


   Chemical Constituents Top


Polysulfides

Polysulfides, a class of organosulfur compounds with a wide range of biological activities, represent the major constituents isolated from P. alliacea [Figure 1]. The first biologically active sulfur-containing compound isolated from P. alliacea was benzyl-2-hydroxyethyl trisulfide (3).[22] Afterward, bioassay-guided fractionation from P. alliacea roots yielded benzyl-2-hydroxyethyl disulfide (2).[23] Dibenzyl trisulfide (DTS, 6) have been often isolated from various preparations obtained from P. alliacea, mainly from the roots.[18],[23],[24],[25],[26],[27] DTS possess a large number of biological activities reported, such as anticancer and antimicrobial.[28] In addition, dibenzyl disulfide (DBDS, 5) and other polysulfides, including benzyl hydroxymethyl sulfide (1), dibenzyl sulfide (4), dibenzyl tetrasulfide (7), di (benzyltrithio) methane (8), and dypropyl disulfide (9), were also commonly identified in extractive preparations obtained from the species.[12],[17],[24],[27],[29]
Figure 1: Chemical structures of polysulfides and flavonoids obtained from Petiveria alliacea

Click here to view


Flavonoids

Flavonoids and flavonoids derivatives were found in an ethanol extract from aerial parts of P. alliacea [Figure 1], namely 6-formyl-8-methyl-7-O-methylpinocembrin (leridal, 10), 6-hydroxymethyl-8-methyl-7-O-methylpinocembrin (leridol, 11), 6-hydroxymethyl-8-methyl-5,7-di-O-methylpinocembrin (5-O-methylleridol, 12), in addition to 3-O-rhamnosides of dihydrokampferol (engeletin, 13), dihydroquercetin (alstibin, 14) and myricetin (15).[30],[31] Furthermore, the fractionation of the ethanol extract led to the isolation of 7-demethylleridal (16), leridal-chalcone (17), petiveral (18) and 4-ethylpetiveral (19).[31]

Terpenoids

P. alliacea presents mainly mono-and triterpenoids in its composition [Figure 2]. The monoterpenes borneol (20), carvacrol (21), cumin alcohol (22), geraniol (23), geranyl acetate (24), palustrol (25) have been identified in essential oils of root, stems, leaves, and flowers.[32],[33],[34] The diterpene phytol (26) has been identified in hydroalcoholic extracts from leaves and roots.[23],[32] Regarding the triterpenes, α-friedelinol (27) was the first isolated of a petroleum ether extract.[28] Barbinervic acid (28) and 3-epiilexgenin A (29) were isolated from an ethanol extract of P. alliacea. Segelman and Segelman [35] have identified isoarborinol (30) and their derivatives in the leaves of the species.
Figure 2: Chemical structures of terpenoids, amino acids derivatives, and volatile compounds found in Petiveria alliacea

Click here to view


Amino acids derivatives

Two diastereomers of S-benzyl-L-cysteine sulfoxide, petiveriin A ((R CR S)-S-benzyl-l-cysteine sulfoxide and petiveriin B ((R CS S)-S-benzyl-l-cysteine sulfoxide (31), were isolated of an amino acid fraction obtained from fresh roots, in addition to S-benzylcysteine (32).[36] Gas chromatography analysis (GC) revealed the presence of cysteine derivatives, namely 6-hydroxyethiin A and B (33), and S-(2-hydroxyethyl) cysteine (34).[37] The authors also identified in trace amounts S-methyl-, S-ethyl-, S-n-propyl- and S-(2-hydroxyethyl) cysteine (structures not shown). In addition, γ-glutamyl-petiveriins A and B (35), and (S C2R C7)-γ-glutamyl-S-benzylcysteine (36) were isolated from roots of P. alliacea.[38] The chemical structures of amino acids derivatives obtained from P. alliacea are shown in [Figure 2].

Essential oils

The chemical composition of essential oils obtained from different parts of P. alliacea and analyzed by GC revealed the presence of some compounds as phenylpropanoids, terpenoids, and numerous benzenoids [Figure 2]. Five phenylpropanoid have been reported for P. alliacea essential oils, including eugenol (37), cinnamaldehyde (38), cis-and trans-stilbenes (39 and 40, respectively), and dillapiole (41).[25],[32],[33],[34]

Analysis of essential oils of P. alliacea revealed that the benzenoids, including benzaldehyde (42), benzyl alcohol (44), and (Z)-3-hexeny benzoate (45), were the predominant components in the root and flower oils.[25],[32],[33],[34] Others benzenoids identified on essential oils of the species include benzoic acid (43), benzyl benzoate (46), benzyl formate (47), benzyl thiol (48), ethyl benzoate (49), phenylacetaldehyde (50), 1-phenylethyl acetate (51), and 1-phenylethyl anthranilate (52). On the other hand, carvacrol (18) constituted the major compound in the stem and leave essential oils.[33]

Thiosulfinates

Thiosulfinates are molecules synthesized through the oxidation of cysteinyl disulfides and play an important role in redox chemistry of proteins.[39] An homogenate of P. alliacea roots afforded various thiosulfinates, namely S-(2-hydroxyethyl) 2-(hydroxyethane) thiosulfinate (53), S-(2-hydroxyethyl) phenylmethanethiosulfinate (54), S-benzyl 2-(hydroxyethane) thiosulfinate (55), and S-benzyl phenylmethanethiosulfinate (petivericin, 56) [Figure 3].[37] The rupture of tissues of P. alliacea causes the release of strong garlic-like odor and lacrimation due to the irritation of nasal and ocular mucous membranes. The responsible compound for this effect was identified from the roots as (Z)-thiobenzaldehyde S-oxide (57).[40] Kubec and Musah [36] have observed that many organosulfur compounds commonly identified in P. alliacea extracts are degradation products of thiosulfinates by enzymatic activity after tissue disruption.
Figure 3: Chemical structures of terpenoids, amino acids derivatives, and volatile compounds found in Petiveria alliacea

Click here to view



   Antibacterial and Antifungal Activities Top


Disc-diffusion test, agar-plate, and broth microdilution assays were performed with crude extracts and isolated compounds from P. alliacea for testing antimicrobial properties, which revealed promising activity against some bacteria and fungi. [Table 1] and [Table 2] summarize the main data about antimicrobial activity of extracts and compounds isolated from P. alliacea, respectively.
Table 1: Antimicrobial activities of Peltaria alliacea extracts against pathogenic microorganisms

Click here to view
Table 2: Antimicrobial activities of sulfur-containing compounds commonly found in Petiveria alliacea extracts against pathogenic microorganisms

Click here to view


Guedes et al.[13] evaluated the antimicrobial activity by broth microdilution method of different extracts obtained from P. alliacea leaves. In this regard, the hexane extract was more active to inhibit Staphylococcus aureus than the polar extract (ethanol 70%), with minimum inhibitory concentrations (MICs) values of 240 μg/mL and 3960 μg/mL, respectively. On the other hand, the methanol extract presented activity against Enterococcus faecalis (MIC of 240 μg/mL). Regarding antifungal activity, only the hydroalcoholic extract was active against Candida parapsilosis (MIC of 250 μg/mL), Candida kefyr and Candida albicans (MIC of 760 μg/mL).[13] Illnait-Zaragozí et al.[41] also reported the antifungal activity of the hydroalcoholic extract of leaves from P. alliacea against several clinical isolates and American Type Culture Collection of Candida species with MIC ranging between 8 μg/mL and 64 μg/mL [Table 1].

Several sulfur-containing compounds isolated of P. alliacea present a broad-spectrum of antimicrobial activity. The first report on antimicrobial activity of an organosulfur compound isolated from P. alliacea is from Szczepanski et al.[22] The authors reported the isolation of benzyl-2-hydroxyethyl trisulfide (3), which was active against S. aureus, Mycobacterium tuberculosis, C. albicans, Trichophyton mentagrophytes, Aspergillus niger, Penicillium chrysogenum and Microsporum gypseum (MICs values ranged between 0.8 μg/mL and 25 μg/mL).[22]

Bioassay-guided fractionation of an organic extract of the roots afforded the isolation of antifungal polysulfides.[24] Bioautography with Cladosporium cladosporioides and Cladosporium sphaerospermum yielded dipropyl disulfide (9), dibenzyl sulfide (4), dibenzyl disulfide (5) and dibenzyl trisulfide (6), which posses potent antifungal activity against with inhibition at concentrations between 0.1 μg/mL and 1.0 μg/mL, similar to the positive control Nystatin (1.0 μg/mL).

The lachrymatory principle of P. alliacea, (Z)-thiobenzaldehyde S-oxide possess antimicrobial activity against C. albicans, Klebsiella pneumoniae,  Escherichia More Details coli, S. aureus and Streptococcus agalactiae in a disk diffusion assay.[40] Kim et al. (2006)[42] also evaluated the antimicrobial activity of different polysulfides isolated from P. alliacea. In this sense, thiosulfinates (54–56) and their degradation products inhibited at low concentrations (MICs values ≤64 μg/mL) the bacteria Bacillus cereus, Mycobacterium smegmatis, Micrococcus luteus, S. agalactiae, S. aureus, E. coli, Stenotrophomonas maltophila, K. pneumonie, and the fungi Aspergillus flavus, Mucor racemosus, Pseudallescheria boydii, C. albicans, C. tropicalis, and Issatchenkia orientalis [Table 2].


   Cytotoxicity and Antiproliferative Activity against Cancer Cell Lines Top


The anticancer properties of P. alliacea were revealed after the Managua story, which occurred in Nicaragua in 1960. It was observed that leukemic cows left to pasture in fields in Nicaragua were healed after consumption of P. alliacea.[4] Thus, researchers have performed several biological assays using some tumor cell lines, in the attempt to find the bioactive compounds present in the extracts, as well as their mechanisms of action.

Rossi et al.[43] and Jovicevic et al.[44] reported in vitro antiproliferative activity of ethanol and aqueous extracts of P. alliacea leaves on cell lines IM9, DAUDI, Molt4, K562, and MCF7. According to them, aqueous preparations were more active than alcoholic extracts evaluated by colorimetric assay using 3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide, which was confirmed by measuring the incorporation of tritiated thymidine. The decoction (1, 10, and 100 μg/mL) inhibited the proliferation by 80%–90% to IM9 in a dose-dependent way, and 50%–60% to MOLT4 and DALDI, and about 20% to K562.

A methanol extract of P. alliacea leaves at a concentration of 125 μg/mL inhibited the growth of murine skin (B16), human leukemia (HL-60), breast (MCF-7), and colon (HCT-8) cell lines at 106.1%, 78.4%, 72.4%, and 94%, respectively.[45] Doxorubicin was used as positive control and inhibited the growth of all tumor cell lines evaluated. On the other hand, Ruffa et al.[46] observed that the methanol extract of P. alliacea leaves was not active against HepG2 cell line in all concentrations tested (15.5–1000 μg/mL).

A bioactive fraction (F4) obtained from the ethanol extract of leaves and stems inhibited the proliferation of A375, Mel Rel, and K562 cell lines at concentrations of 35.2, 36.3, and 32.0 μg/mL, respectively (concentrations ranged between 1.8 μg/ml and 125 μg/ml).[17] Normal fibroblasts and human mononuclear cells without phytohaemagglutinin exhibited IC50 of 440 μg/mL and 121 μg/mL, respectively. Cifuentes et al.[12] and Hernández et al.[47] have revealed cytotoxic activity of ethyl acetate fractions obtained from leaves and stems against K562, NB4, and 4T1 (breast adenocarcinoma cell line) cell lines at a concentration of approximately 50 and 29.3 μg/mL, respectivelly [Table 2].

Bioassay-guided fractionation of the petroleum ether extract of P. alliacea roots led to the isolation of biologically active compounds against HL-60 cell line.[23] The petroleum ether extract exhibited effect on HL-60 cell differentiation, with EC50 =3.6 μg/mL (positive control: All-trans-retinoic acid, EC50 =0.1 μg/mL). The fractionation of these extract led to the isolation of the active compounds DTS (6) and 2-[(phenylmethyl) dithio]-ethanol (2) that caused HL-60 cell differentiation at concentrations of 3 and 0.3 μg/mL, respectively. Several studies have reported the antiproliferative and cytotoxic activity of DTS and related compounds obtained by chemical optimization (e.g., bis (p-fluorobenzyl) trisulfide) on various tumor cells, and efforts had been made to elucidate their mechanism of action in cancer.[12],[14],[48],[49],[50],[51],[52]

Mechanism of action

In addition to cytotoxic and antiproliferative investigations, some authors also evaluated the possible mechanism for these activities in cell lines. Urueña et al.[17] using flow cytometry showed that melanoma tumor cells treated with a P. alliacea fraction (concentrations ranged between 7.8 μg/mL and 31.2 μg/mL) induced G2 phase arrest. The fraction disturbed the actin cytoskeleton organization after 24 h of incubation, induced apoptosis in a mitochondria-independent way, and reduced the tumor cell clonogenic survival after 14 days when compared to controls treatment (positive controls: etoposide and vincristine; negative control: ethanol 0.2%). Proteomic techniques were performed to characterize the “protein expression signature” over these tumor cell lines, and they were analyzed through differential protein expression by HPLC-Chip/MS analysis.[17] The proteomic analysis results revealed down-regulation of cytoskeleton proteins, which is related to cytoskeleton disruption and according to the authors, changes in the concentration of some proteins that are involved in translation and transduction processes could explain the decrease of melanoma tumor cells clonogenicity.

DTS, a polysulfide often identified in P. alliacea, led to a reversible disassembly of microtubules through the decrease of total expression of tubulin (0.1 μM) and caused a decrease in phosphorylation of erk1/erk2 protein kinases (0.5 μM) in SH-SY5Y cell line.[14] Cytoskeleton proteins, such as tubulin and actin, play important functions in normal and tumoral cell physiology and represent significant targets of emergent anticancer agents.[53],[54] Thus, compounds that act in cytoskeleton targets play an important role in cancer therapy, affecting directly proteins that regulate several cellular processes linked to transformation, as cell proliferation and apoptosis.

Apoptosis is an organized cellular event that occurs in normal and pathological conditions. The programmed cell death through apoptosis is also pivotal in cancer treatment and is considered a common target of cancer therapeutic strategies.[55] Apoptosis via intrinsic pathway represents an important target to cancer treatment and discovery of novel apoptotic inducers is one of the current concerns in anticancer research. Regarding apoptosis, Cifuentes et al.[12] revealed that fractions obtained from ethyl acetate extract of P. alliacea leaves and stems induced mitochondrial membrane depolarization after 8 h of treatment in different tumor cell lines at a concentration of 31.2 μg/ml using as positive and negative controls, P2Et (precipitate of ethyl acetate fraction obtained from ethanol extract of Caesalpinia spinosa) and ethanol, respectively. They also investigated the effects of S2 and S3 at concentration of 6.2 μg/ml on the modulation of heat shock protein 70 (Hsp70). Western blotting analysis of K562 cells treated for 10 h and exposed to thermal stress revealed that S3 fraction decreased the Hsp70 protein expression as compared to positive control (quercetin at a concentration of 100 μM). In normal cells, Hsp proteins protect them from environmental stress damage, and in cancer cells, they promote cell proliferation, as well as inhibit cellular death pathways.[56] Thus, the study of the regulation of Hsp proteins represents an interesting target in the evaluation of medicinal plants with potential anticancer activities.

On the other hand, Hernández et al.[47] revealed that different concentrations (7.3, 14.6, and 29.3 μg/mL) of an ethyl acetate fraction induce apoptosis of 4T1 cells, but it not affects mitochondrial membrane depolarization. The fraction also induces the activation of caspase-3 and DNA fragmentation on 4T1 cells. According to the authors, the cytotoxicity activity may be explained by the activation of the glycolytic pathway enzymes.

Santander et al.[57] revealed that an ethyl acetate fraction (FAST 8) obtained from P. alliacea induced changes in gene expression profile (21 genes were affected) of K562 cells treated for 24 h at a concentration of 25 μg/mL as compared to negative control (ethanol 0.2%). Nevertheless, the authors suggested that the identification of modulated genes treated with P. alliacea could provide new targets in cancer therapy.


   Immunomodulatory Activity Top


P. alliacea crude extracts and their isolated constituents present good immunomodulating properties through cell mediation and modulation of different cytokines release. Currently, several herbal preparation containing P. alliacea are available in the market to boost or support immunity.[6]

The first study about the effects of P. alliacea on the immune system was carried out by Delaveau et al.[58] The authors investigated the protective effect of the ethanol extract of P. alliacea roots and its unsaponifiable fraction on phagocytic activity of the reticuloendothelial system in male Swiss mice infected with a lethal dose of E. coli O111:B4. Both extract and fraction at a final concentration of 50 mg/kg (i.p.) showed protective effects due to the enhancement of the reticuloendothelial system that stimulates E. coli O111:B4 phagocytosis.

The administration of DTS to mice (11.0 mg/kg/day, i.p.) twice weekly for 3 weeks significantly increased the thymus weight (40.5 ± 2.6 mg, P < 0.05), the number of Peyer's patches (9.2 ± 1.3 mg), and the differential cell count value (7.65 ± 0.98) when comparing with control group (19.2 ± 1.5 mg, 5.0 ± 0.9 mg, 2.85 ± 0.73).[18] Lopes-Martins et al.[59] related that oral administration of a root hydroalcoholic extract (31.4 mg/kg body wt. and 43.9 mg/kg body wt.) decreased the number of migrating neutrophils, mononuclear cells and eosinophils, evaluated in an animal model of carrageenan-induced pleurisy.

Marini et al.[60] reported that a plant decoction of whole plant increased the production of cytokines interleukin-2 (IL-2) and IL-4 (IL-2: 4 IU/mL, IL-4: 4 IU/mL), and interferon (IFN) (30 IU/mL) in murine splenocytes cultures as compared with control group (IL-2: 0 IU/mL, IL-4: 0 IU/mL, and IFN: <5 IU/mL). In addition, the aqueous extract increased at 100% the activity of NK cells after 24 h of treatment, which could be explained by the IFN production. P. alliacea decoction also (concentrations ranged between 0.001 μg/mL and 1000 μg/mL) induced cell proliferation in splenocyte cultures from 10 months old mice (>5000 CPM from 10, 100 and 1000 μg/mL; P < 0.001) as compared to Con-A control after 48 h of exposure (1458 ± 187 CPM).[61] There was also an increase of IL-2 receptor expression in stimulated mice splenocytes cultures after the treatment with P. alliacea decoction.

A hydroalcoholic extract of P. alliacea roots showed a protective effect against Listeria monocytogenes infection.[62],[63] Pretreatment of Balb/cj mice with 1000 mg/kg/day (p.o.) of the extract, for 5 days prior the infection, increased the percentage of survivors in 30% (P< 0.05) and the number of granulocyte/macrophage colonies (CFU-GM) from 47.60 ± 10.3 in nontreated group to 144.00 ± 11.2 (P< 0.01).[62] The extract also increased the production of cytokines IL-2 and IFN-γ after mice infection and enhanced natural killer cell activity, when compared to control groups not treated.[63] Th2 cytokines IL-4 and IL-10 were the same as the noninfected and nontreated groups.

Santander et al.[15] evaluated the immunomodulatory activity of the ethyl acetate soluble and aqueous fractions of leaves and stems from P. alliacea using human monocyte-derived dendritic cells (DCs) stimulated with lipopolysaccharide (1 μg/mL). The fractions (6–63 μg/mL) induced morphological changes and co-stimulatory expression of CD86 in DC, indicating partial maturation. Moreover, pro-inflammatory cytokines IL-1β, IL-6, IL-8, IL-10, IL-12p70, and tumor necrosis factor-α were secreted, while nuclear factor- kappa B gene expression was upregulated and transforming growth factor β gene expression decreased.

Batista-Duharte et al.[64] reported that oral administration of leaves and stems powder of P. alliacea for 5 days (400 or 1200 mg/kg) showed immunoprotective effects on 5-fluorouracil-induced myelosuppression in Balb/c female mice. Treatment with P. alliacea increased the global leukocyte count, cellularity and number of antibody-forming cells (AFCs) IgG, when compared with control groups treated with a saline solution or 5-FU only.

It appears that P. alliacea acts on the immune system through modulation of Th1 response (i.e., enhancing the expression of pro-inflammatory cytokines in bacterial infections). Moreover, there was also the production of anti-inflammatory cytokine IL-10, which regulates inflammatory events by suppression of pro-inflammatory cytokines and other stimulating factors.[65] The expression of IL-10 after administration of P. alliacea preparations may justify the anti-inflammatory activity reported by some authors [66],[67] and could be related to the finalization of Th1-type responses. Immunomodulation is interesting in the prevention of several infectious diseases and can be used in cancer treatment along with the classic drugs, improving the immune status of patients.

Regarding chemical constituents, triterpenes are a class of secondary metabolites that present activities on the immune system.[68] Some authors had isolated these compounds mainly in essential oils of P. alliacea. Alamgir and Uddin [69] related that the compounds β-sitosterol and daucosterol, both present in the plant, exhibit immunomodulatory activity.


   Conclusions Top


Medicinal plants and their derivatives represent an emerging potential source of discovery of new drugs to treat several disorders at present. P. alliacea is a cosmopolitan plant that provides easy access to consumption by population. Till date, data have revealed that P. alliacea preparations present in its constitution many biologically active compounds. In this sense, several sulfur-containing compounds (i.e., polysulfides and thiosulfinates) have revealed higher antimicrobial activity against pathogenic bacteria and fungi at low concentrations.

Furthermore, many investigations conducted with P. alliacea showed its promising potential for the treatment of cancer with a mechanism of action gathering sophisticated machinery of cellular damage, mainly by deregulation of the cytoskeleton proteins. In the immune system, the species act in the enhancement of the expression of pro-inflammatory cytokines during bacterial infections and modulating anti-inflammatory responses, with potentiates the chemotherapy treatment during cancer or infections.

Further investigations are needed to elucidate the synergistic/antagonistic mechanisms by which the compounds present in the plant extracts may interact to produce the pharmacological activities.

Acute or chronic preclinical studies have revealed that P. alliacea preparations did not produce toxic effects in rodent experimental models with doses ranging between 0.5 mg/kg and 10000 mg/kg.[70],[71],[72],[73] However, data in respect of side effects in animal models is contradictory.[74] Thus, more studies are required to ensure the safety and characterize potential side effects after P. alliacea administration.

Regarding genotoxicity, Hoyos et al.[75] revealed that the plant has mutagenic agents, potentially carcinogenic and that its consumption in large quantities may represent a risk of development of health problems in its users. In fact, our group has revealed that the hydroalcoholic extract of aerial parts possess in vitro genotoxic effects affecting DNA. However, there is no in vivo genotoxic potential assayed by micronucleus assay in rodents.[76]

This review may raise new trends in the studies with P. alliacea as well as contribute to the scientific community by offering data for decision-making with regard to its use in diseases treatment and pharmaceutical technological products development. The species has a world biological interest due to its characteristics; however, its use must be rational to ensure its therapeutic benefits. In addition, clinical trials are required to validate the therapeutic use of preparations obtained from P. alliacea, to obtain safe doses, evaluate the potential side effects and treatment schedule.

Acknowledgment

We are very grateful to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), for scientific fellowships. We gratefully acknowledge the financial support of Pró-Reitoria de Pesquisa e Pós-Graduação from UFPA (PROPESP/UFPA).

Financial support and sponsorship

We are very grateful for scientific fellowships from Coordination of Superior Level Staff Improvement (CAPES).

Conflicts of interest

There are no conflicts of interest.



 
   References Top

1.
Camargo MT. The weapon of the slaves against their masters. Rev Pós Ciênc Sociais 2007;4:31-42.  Back to cited text no. 1
    
2.
Linnaeus C. Species Plantarum. 1st ed. Stolckolm: Salvius; 1753.  Back to cited text no. 2
    
3.
Di Stasi LC, Feitosa SB, Hiruma-Lima CA. Caryophyllales medicinais. In: Di Stasi LC, Hiruma-Lima CA, editors. Medicinal Plants in the Amazonian region and Atlantic Forest. 2nd ed. São Paulo: Editora Unesp; 2002. p. 149-73.  Back to cited text no. 3
    
4.
Alonso J. Tratado de Fitofármacos y Nutracéuticos. 2nd ed. Rosário: Corpus Editoria y Distribuidora; 2007.  Back to cited text no. 4
    
5.
Camargo MT. Etnopharmacobotanical contribution to a survey on Petiveria alliacea L. –Phytolaccaceae– (“amansa-senhor”) and to the hipoglucemic activity related to mental disturbs. Dominguezia 2007;23:21-7.  Back to cited text no. 5
    
6.
Lemus Rodríguez Z, García Pérez ME, Batista Duharte A, de la Guardia Peña O, Alfonso Castillo A. The anamú tablet: an herbal immunostimulant medication. Medisan 2004;8:57-64.  Back to cited text no. 6
    
7.
Alonso-Castro AJ, Villarreal ML, Salazar-Olivo LA, Gomez-Sanchez M, Dominguez F, Garcia-Carranca A, et al. Mexican medicinal plants used for cancer treatment: Pharmacological, phytochemical and ethnobotanical studies. J Ethnopharmacol 2011;133:945-72.  Back to cited text no. 7
    
8.
Folliard T. External use of phytotherapy in South and Central America — Mexico and Guatemala (Part 1). Phytothérapie 2008;6:175-83.  Back to cited text no. 8
    
9.
Sanz-Biset J, Campos-de-la-Cruz J, Epiquién-Rivera MA, Cañigueral S. A first survey on the medicinal plants of the Chazuta valley (Peruvian Amazon). J Ethnopharmacol 2009;122:333-62.  Back to cited text no. 9
    
10.
Vandebroek I, Balick MJ, Ososki A, Kronenberg F, Yukes J, Wade C, et al. The importance of botellas and other plant mixtures in Dominican traditional medicine. J Ethnopharmacol 2010;128:20-41.  Back to cited text no. 10
    
11.
Volpato G, Godínez D, Beyra A, Barreto A. Uses of medicinal plants by Haitian immigrants and their descendants in the Province of Camagüey, Cuba. J Ethnobiol Ethnomed 2009;5:16.  Back to cited text no. 11
    
12.
Cifuentes MC, Castañeda DM, Urueña CP, Fiorentino S. A fraction from Petiveria alliacea induces apoptosis via a mitochondria-dependent pathway and regulates HSP70 expression. Univ Sci (Bogota) 2009;14:125-34.  Back to cited text no. 12
    
13.
Guedes RC, Nogueira NG, Fusco-Almeida AM, Souza CR, Oliveira WP. Atividade antimicrobiana de extratos brutos de Petiveria alliacea L. Latin. Am J Pharm 2009;28:520-4.  Back to cited text no. 13
    
14.
Rösner H, Williams LA, Jung A, Kraus W. Disassembly of microtubules and inhibition of neurite outgrowth, neuroblastoma cell proliferation, and MAP kinase tyrosine dephosphorylation by dibenzyl trisulphide. Biochim Biophys Acta 2001;1540:166-77.  Back to cited text no. 14
    
15.
Santander SP, Hernández JF, Barreto CC, Masayuki A, Moins-Teisserenc H, Fiorentino S, et al. Immunomodulatory effects of aqueous and organic fractions from Petiveria alliacea on human dendritic cells. Am J Chin Med 2012;40:833-44.  Back to cited text no. 15
    
16.
Silva ML, Luz DA, Paixão TP, Silva JP, Belém-Filho IJ, Fernandes LM, et al. Petiveria alliacea exerts mnemonic and learning effects on rats. J Ethnopharmacol 2015;169:124-9.  Back to cited text no. 16
    
17.
Urueña C, Cifuentes C, Castañeda D, Arango A, Kaur P, Asea A, et al. Petiveria alliacea extracts uses multiple mechanisms to inhibit growth of human and mouse tumoral cells. BMC Complement Altern Med 2008;8:60.  Back to cited text no. 17
    
18.
Williams LA, The TL, Gardner MT, Fletcher CK, Naravane A, Gibbs N, et al. Immunomodulatory activities of Petiveria alliacea L. Phytother Res 1997;11:251-3.  Back to cited text no. 18
    
19.
Rocha LD, Maranho LT, Preussler KH. Stem and leaf structural organization of Petiveria alliacea L., Phytolaccaceae. Rev Bras Farmacogn 2006;87:98-101.  Back to cited text no. 19
    
20.
Rocha AB. Botanic study of Petiveria alliacea L.: External morphology and anatomy. Doctorate Thesis, Universidade Estadual Paulista; 1969.  Back to cited text no. 20
    
21.
The Plant List. Version 1.1. Available from: http://www.theplantlist.org/. [Last accessed on 2015 Jan 19].  Back to cited text no. 21
    
22.
Szczepanski C, Zgorzelak P, Hoyer GA. Isolation, structure elucidation and synthesis of an antimicrobial substance of Petiveria alliacea L. Arzneimittelforschung 1972;22:1975-6.  Back to cited text no. 22
    
23.
Mata-Greenwood E, Ito A, Westenburg H, Cui B, Mehta RG, Kinghorn AD, et al. Discovery of novel inducers of cellular differentiation using HL-60 promyelocytic cells. Anticancer Res 2001;21:1763-70.  Back to cited text no. 23
    
24.
Benevides PJ, Young MC, Giesbrecht AM, Roque NF, Bolzani VS. Antifungal polysulphides from Petiveria alliacea L. Phytochemistry 2001;57:743-7.  Back to cited text no. 24
    
25.
Bezerra JN. Chemical composition, phytonematicide activity and insecticide of Tipi (Petiveria alliaceae). Master D. Dissertation, Graduate Program in Organic Chemistry, Federal University of Ceará, Fortaleza, Brazil; 2006.  Back to cited text no. 25
    
26.
Johnson L, Williams LA, Roberts EV. An insecticidal and acaricidal polysulfide metabolite from the roots of Petiveria alliacea. Pest Manag Sci 1997;50:228-32.  Back to cited text no. 26
    
27.
Rosado-Aguilar JA, Aguilar-Caballero A, Rodriguez-Vivas RI, Borges-Argaez R, Garcia-Vazquez Z, Mendez-Gonzalez M, et al. Acaricidal activity of extracts from Petiveria alliacea (Phytolaccaceae) against the cattle tick, Rhipicephalus (Boophilus) microplus (Acari: Ixodidae). Vet Parasitol 2010;168:299-303.  Back to cited text no. 27
    
28.
De Sousa JR, Demuner AJ, Pinheiro JA, Breitmaier E, Cassels BK. Dibenzyl trisulphide and trans-N-methyl-4-methoxyproline from Petiveria alliacea. Phytochemistry 1990;29:3653-5.  Back to cited text no. 28
    
29.
Kubec R, Cody RB, Dane AJ, Musah RA, Schraml J, Attekkatte A, et al. Applications of direct analysis in real time-mass spectrometry (DART-MS) in allium chemistry. (Z)-Butanethial S-oxide and 1-butenyl thiosulfinates and their S-(E)-1-butenylcysteine S-oxide precursor from Allium siculum. J Agric Food Chem 2010;58:1121-8.  Back to cited text no. 29
    
30.
Delle Monache F, Cuca Suarez LE. 6-C-formyl and 6-C-hydroxymethyl flavanones from Petiveria alliacea. Phytochemistry 1992;31:2481-2.  Back to cited text no. 30
    
31.
Delle Monache F, Menichini F, Cuca Suarez LE. Petiveria alliacea. Part 2. Further flavonoids and triterpenes. Gazz Chim Ital 1996;126:275-8.  Back to cited text no. 31
    
32.
Ayedoun MA, Moudachirou M, Sossou PV, Garneau FX, Gagnon H, Jean FI. Volatile constituents of the root oil of Petiveria alliacea L. from benin. J Essent Oil Res 1998;10:645-6.  Back to cited text no. 32
    
33.
Neves IA, Câmara CA, Oliveira JC, Almeida AV. Acaricidal activity and essential oil composition of Petiveria alliacea L. from Pernambuco (Northeast Brazil). J Essent Oil Res 2011;23:23-6.  Back to cited text no. 33
    
34.
Zoghbi MG, Andrade EH, Maia JG. Volatile constituents from Adenocalymma alliaceum Miers and Petiveria alliacea L., two medicinal herbs of the Amazon. Flavour Fragr J 2002;17:133-5.  Back to cited text no. 34
    
35.
Segelman FP, Segelman AB. Constituents of Petiveria alliacea. Phytolaccaceae. Part I. Isolation of isoarborinol, isoarborinol acetate and isoarborinol cinamate for the leaves. Lloydia 1975;8:537.  Back to cited text no. 35
    
36.
Kubec R, Musah RA. Cysteine sulfoxide derivatives in Petiveria alliacea. Phytochemistry 2001;58:981-5.  Back to cited text no. 36
    
37.
Kubec R, Kim S, Musah RA. S-substituted cysteine derivatives and thiosulfinate formation in Petiveria alliacea-part II. Phytochemistry 2002;61:675-80.  Back to cited text no. 37
    
38.
Kubec R, Musah RA. Gamma-glutamyl dipeptides in Petiveria alliacea. Phytochemistry 2005;66:2494-7.  Back to cited text no. 38
    
39.
Amorati R, Lynett PT, Valgimigli L, Pratt DA. The reaction of sulfenic acids with peroxyl radicals: Insights into the radical-trapping antioxidant activity of plant-derived thiosulfinates. Chemistry 2012;18:6370-9.  Back to cited text no. 39
    
40.
Kubec R, Kim S, Musah RA. The lachrymatory principle of Petiveria alliacea. Phytochemistry 2003;63:37-40.  Back to cited text no. 40
    
41.
Illnait-Zaragozí MT, Martínez RE, Ferrer JI, Andreu CM, Machín GF, Lancha MR, et al. In vitro antifungal activity of crude hydro-alcoholic extract of Petiveria alliacea L on clinical Candida isolates. Clin Microbiol 2014;3:159.  Back to cited text no. 41
    
42.
Kim S, Kubec R, Musah RA. Antibacterial and antifungal activity of sulfur-containing compounds from Petiveria alliacea L. J Ethnopharmacol. 2006; 104: 188-192.  Back to cited text no. 42
    
43.
Rossi V, Jovicevic L, Troiani MP, Bonanomi M, Mazzanti G. Antiproliferative effects of Petiveria alliacea on several tumor cell lines. Pharmacol Res 1990;22:434.  Back to cited text no. 43
    
44.
Jovicevic L, Troiani MP, Capezzone de Joannon A, Saso L, Mazzanti G, Rossi V. In vitro antiproliferative activity of Petiveria alliacea L. on several tumor cell lines. Pharmacol Res 1993;27:105-6.  Back to cited text no. 44
    
45.
dos Santos Júnior HM, Oliveira DF, de Carvalho DA, Pinto JM, Campos VA, Mourão AR, et al. Evaluation of native and exotic Brazilian plants for anticancer activity. J Nat Med 2010;64:231-8.  Back to cited text no. 45
    
46.
Ruffa MJ, Ferraro G, Wagner ML, Calcagno ML, Campos RH, Cavallaro L, et al. Cytotoxic effect of argentine medicinal plant extracts on human hepatocellular carcinoma cell line. J Ethnopharmacol 2002;79:335-9.  Back to cited text no. 46
    
47.
Hernández JF, Urueña CP, Cifuentes MC, Sandoval TA, Pombo LM, Castañeda D, et al. A Petiveria alliacea standardized fraction induces breast adenocarcinoma cell death by modulating glycolytic metabolism. J Ethnopharmacol 2014;153:641-9.  Back to cited text no. 47
    
48.
An H, Zhu J, Wang X, Xu X. Synthesis and anti-tumor evaluation of new trisulfide derivatives. Bioorg Med Chem Lett 2006;16:4826-9.  Back to cited text no. 48
    
49.
Williams LA, Rösner H, Möller W, Conrad J, Nkurunziza JP, Kraus W, et al. In vitro anti-proliferation/cytotoxic activity of sixty natural products on the human SH-SY5Y neuroblastoma cells with specific reference to dibenzyl trisulphide. West Indian Med J 2004;53:208-19.  Back to cited text no. 49
    
50.
Williams LA, Kraus W. Anti-proliferation/cytotoxic action of dibenzyl trisulphide, a secondary metabolite of Petiveria alliacea. Jamaican J Sci Technol 2004;15:54-60.  Back to cited text no. 50
    
51.
Williams LA, Rosner H, Levy HG, Barton EN. A critical review of the therapeutic potential of dibenzyl trisulphide isolated from Petiveria alliacea L (Guinea hen weed, anamu). West Indian Med J 2007;56:17-21.  Back to cited text no. 51
    
52.
Williams LA, Rösner H, Kraus W. Molecules with potential for cancer therapy in the developing world: Dibenzyl trisulfide (DTS). In: Nelson KE, Jones-Nelson B, editors. Genomics Applications for the Developing World. 1st ed. New York: Springer; 2012. p. 273-8.  Back to cited text no. 52
    
53.
Jordan MA, Wilson L. Microtubules and actin filaments: Dynamic targets for cancer chemotherapy. Curr Opin Cell Biol 1998;10:123-30.  Back to cited text no. 53
    
54.
Pawlak G, Helfman DM. Cytoskeletal changes in cell transformation and tumorigenesis. Curr Opin Genet Dev 2001;11:41-7.  Back to cited text no. 54
    
55.
Wong RS. Apoptosis in cancer: From pathogenesis to treatment. J Exp Clin Cancer Res 2011;30:87.  Back to cited text no. 55
    
56.
Soo ET, Yip GW, Lwin ZM, Kumar SD, Bay BH. Heat shock proteins as novel therapeutic targets in cancer. In Vivo 2008;22:311-5.  Back to cited text no. 56
    
57.
Santander SP, Urueña C, Castañeda D, Cifuentes C, Aristizábal F, Cordero C. Influencia del tratamiento de Petiveria alliacea en la expresión diferencial de genes en células tumorales. Rev Univ Méd 2009;50:284-96.  Back to cited text no. 57
    
58.
Delaveau P, Lallouette P, Tessier HM. Stimulation of the phagocytic activity of reticuloendothelial system by plant drugs. Planta Med 1980;40:49-54.  Back to cited text no. 58
    
59.
Lopes-Martins RA, Pegoraro DH, Woisky R, Penna SC, Sertié JA. The anti-inflammatory and analgesic effects of a crude extract of Petiveria alliacea L. (Phytolaccaceae). Phytomedicine 2002;9:245-8.  Back to cited text no. 59
    
60.
Marini S, Jovicevic L, Milanese C, Giardina B, Tentori L, Leone MG. Effects of Petiveria alliacea L. on cytokine production and natural killer cell activity. Pharmacol Res 1993;27:107-8.  Back to cited text no. 60
    
61.
Rossi V, Marini S, Jovicevic L, D'Atri S, Turri M, Giardina B. Effects of Petiveria alliacea L. on cell immunity. Pharmacol Res 1993;27:111-2.  Back to cited text no. 61
    
62.
Quadros MR, Souza Brito AR, Queiroz ML. Petiveria alliacea L. extract protects mice against Listeria monocytogenes infection – Effects on bone marrow progenitor cells. Immunopharmacol Immunotoxicol 1999;21:109-24.  Back to cited text no. 62
    
63.
Queiroz ML, Quadros MR, Santos LM. Cytokine profile and natural killer cell activity in Listeria monocytogenes infected mice treated orally with Petiveria alliacea extract. Immunopharmacol Immunotoxicol 2000;22:501-18.  Back to cited text no. 63
    
64.
Batista-Duharte A, Urdaneta Laffita I, Colón Suárez M, Esmérido Betancourt J, Puente Zapata E, Castillo AA. Protecting effect of Petiveria alliacea (Anamu) on the immunosuppression induced by 5-fluoruracil in Balb/c mice. Bol Latinoam Caribe Plantas Med Aromáticas 2011;10:256-64.  Back to cited text no. 64
    
65.
Moore KW, de Waal Malefyt R, Coffman RL, O'Garra A. Interleukin-10 and the interleukin-10 receptor. Annu Rev Immunol 2001;19:683-765.  Back to cited text no. 65
    
66.
Germano DH, Caldeira TT, Mazella AA, Sertie JA, Bacchi EM. Topical anti-inflammatory activity and toxicity of Petiveria alliacea. Fitoterapia 1993;64:459-67.  Back to cited text no. 66
    
67.
Germano DH, Sertie JA, Bacchi EM. Pharmacological assay of Petiveria alliacea L.: Oral anti-inflammatory activity and gastrotoxicity of a hydroalcoholic root extract. Fitoterapia 1995;66:195-202.  Back to cited text no. 67
    
68.
Ríos JL. Effects of triterpenes on the immune system. J Ethnopharmacol 2010;128:1-4.  Back to cited text no. 68
    
69.
Alamgir M, Uddin SJ. Recent advances on the ethnomedicinal plants as immunomodulatory agents. In: Chattopadhyay D, editor. Ethnomedicine: A Source of Complementary Therapeutics. 1st ed. Kerala: Research Signpost; 2010. p. 227-44.  Back to cited text no. 69
    
70.
Audi EA, Vieira de Campos EJ, Rufino M, Garcia Cortez D, Bersani-Amado CA, Lira Soarez LA, et al. Petiveria alliacea L.: Plant drug quality control, hydroalcoholic extract standardization and pharmacological assay of lyophilized extract. Latin Am J Pharm 2001;20:225-32.  Back to cited text no. 70
    
71.
Fontoura MC, Silva SN, Abreu IC, Gonçalves JR, Borges MO, Borges AC. Effect of Petiveria alliacea L. in the intestinal secretion and motility of rodents. Braz J Med Plants 2005;7:37-43.  Back to cited text no. 71
    
72.
García-González M, Morales TC, Ocampo R, Pazos L. Subchronic and acute preclinic oxicity and some pharmacological effects of the water extract from leaves of Petiveria alliacea (Phytolaccaceae). Rev Biol Trop 2006;54:1323-26.  Back to cited text no. 72
    
73.
Ximenes SC. Pre-clinical toxicological assays with dry crude extract from leaves of Petiveria alliacea Linné. Master D. Dissertation, Graduate Program in Pharmaceutical Sciences, Federal University of Pernambuco, Recife, Brazil; 2008.  Back to cited text no. 73
    
74.
Luz DA, Pinheiro AM, Silva ML, Monteiro MC, Prediger RD, Ferraz Maia CS, et al. Ethnobotany, phytochemistry and neuropharmacological effects of Petiveria alliacea L. (Phytolaccaceae): A review. J Ethnopharmacol 2016;185:182-201.  Back to cited text no. 74
    
75.
Hoyos LS, Au WW, Heo MY, Morris DL, Legator MS. Evaluation of the genotoxic effects of a folk medicine, Petiveria alliacea (Anamu). Mutat Res 1992;280:29-34.  Back to cited text no. 75
    
76.
Silva JP, de Oliveira FR, da Paixão TP, Malcher NS, dos Santos PC, Baetas AC, et al. In vitro and in vivo assessment of genotoxic activity of Petiveria alliacea. Afr J Pharm Pharmacol 2016;10:718-27.  Back to cited text no. 76
    


    Figures

  [Figure 1], [Figure 2], [Figure 3]
 
 
    Tables

  [Table 1], [Table 2]



 

Top
   
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
    Abstract
   Introduction
    Botanical Consid...
    Chemical Constit...
    Antibacterial an...
    Cytotoxicity and...
    Immunomodulatory...
   Conclusions
    References
    Article Figures
    Article Tables

 Article Access Statistics
    Viewed2087    
    Printed89    
    Emailed0    
    PDF Downloaded7    
    Comments [Add]    

Recommend this journal