Structural Elucidation and Antibacterial Activity Studies of Leaf Extracts of  Withania somnifera

Amsalu Genanaw Gebeyehu; Kumlachew Zelalem Walle; Meseret ZEbeaman Birhanu; Rahel Gebeyehu

doi:10.22146/ijc.74750

Structural Elucidation and Antibacterial Activity Studies of Leaf Extracts of Withania somnifera

https://doi.org/10.22146/ijc.74750

Amsalu Genanaw Gebeyehu^(1*), Kumlachew Zelalem Walle⁽²⁾, Meseret ZEbeaman Birhanu⁽³⁾, Rahel Gebeyehu⁽⁴⁾

(1) Department of Chemistry, Woldia University, Woldia City, Amaraha Region, Ethiopia
(2) Department of Chemistry, University of Gondar, Gondar, Ethiopia
(3) Department of Chemistry, Debre Markos University, Debre Markos, Ethiopia
(4) Bacterial and Viral Diseases Research Directorate (BVDRD), Armauer Hansen Research Institute (AHRI), Jimma Road, Addis Ababa, Ethiopia
(*) Corresponding Author

Abstract

Withania somnifera (W. somnifera), a small, woody shrub in the Solanaceae family, has been studied using a phytochemical test, antibacterial activity and partial characterizations. Air-dried and powdered leaves of the plant were extracted with maceration over an electrical shaker using the solvent chloroform and methanol. After crude extracts of the plant were concentrated, the diffusion antibacterial susceptibility test was carried out on 25, 50, 75, and 100 mg/mL of chloroform and methanol crude extract. The bacteria used were S. aureus, S. pneumonia, E. coli, and S. typhi. Each antibacterial activity test was carried out three times. The most active crude extract of the plant was subjected to a phytochemical test and fractionation with column chromatography. Chloroform and methanol extract of the plant inhibits all cultures of four bacteria. Both chloroform and methanol extract of W. Somnifera inhibits both gram-positive and negative bacterium with a comparable inhibition zone with the standard antibiotics, amoxicillin, gentamicin, and cefoxitine. In addition, it gives a maximum inhibition zone than that of amoxicillin, starting from 25 to 100 mg/mL. Methanol extract of W. somnifera contains phenolic, alkaloids, flavonoids, tannins, and phytosteroids. Partial characterization of pure fractions by using ¹H-NMR, ¹³C-NMR, Dept-135 NMR, and IR spectroscopy, the compound WS-1 affords withaferin A. Withaferine A shows antibacterial activity with an inhibition zone of 11, 10.5, 11, and 9 mm against the bacterium S. aureus, S. pneumoniae, E. coli, and S. typhi respectively.

Keywords

antibacterial test; inhibition zone; partial characterization; withaferin A

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References

[1] World Health Organization, 2001, Legal Status of Traditional Medicine and Complementary/Alternative Medicine: A Worldwide Review, World Health Organization, Geneva.

[2] Ekor, M., 2014, The growing use of herbal medicines: Issues relating to adverse reactions and challenges in monitoring safety, Front. Pharmacol., 4, 177.

[3] Bekele, E., 2007, Study on Actual Situation of Medicinal Plants in Ethiopia, Japan Association for international Collaboration of Agriculture and Forestry, Addis Ababa.

[4] Muluye, B.A., and Ayicheh, W.M., 2020, Medicinal plants utilized for hepatic disorders in Ethiopian traditional medical practices: A review, Clin. Phytosci., 6 (1), 52.

[5] El-Sakka, M., and Ahmad, J., 2009/2010, Manual of Phytochemistry (1), Department of Pharmacognosy, Al Azhar University, Egypt.

[6] Bhattacharya, J., Mandal, A., Das, K., and Nandi, D.K., 2011, Effect of root extract of Withania sominifera on probiotics, in vitro, Int. J. Innovative Pharm. Res., 2 (1), 74–77.

[7] Enyiukwu, D.N., Awurum, A.N., and Nwaneri, A.J., 2014, Efficacy of plant-derived pesticides in the control of myco-induced postharvest rots of tubers and agricultural products: A review, Net J. Agric. Sci., 2 (1), 30–46.

[8] Mushtaq, M., Durrani, F.R., Imtiaz, N., Sadique, U., Hafeez, A., Akhtar, S., and Ahmad, S., 2012, Effect of administration of Withania somnifera on some hematological and immunological profile of broiler chicks, Pak. Vet. J., 32 (1), 70–72.

[9] Vaishnavi, K., Saxena, N., Shah, N., Singh, R., Manjunath, K., Uthayakumar, M., Kanaujia, S.P., Kaul, S.C., Sekar, K., and Wadhwa, R., 2012, Differential activities of the two closely related withanolides, withaferin A and withanone: Bioinformatics and experimental evidences, PLoS One, 7 (9), e44419.

[10] Al-Ani, N., Hadi, S.A., and Nazar, R., 2013, Antimicrobial activities of Withania somnifera crude extract, Sci. Agric., 4 (3), 74–76.

[11] Vyas, V.K., Bhandari, P., and Patidar, R., 2011, A comprehensive review on Withania somnifera Dunal, J. Nat. Rem., 11 (1), 1–13.

[12] Alfonso, D., Bernardinelli, G., and Kapetanidis, I., 1993, Withanolides from Iochroma coccineum, Phytochemistry, 34 (2), 517–521.

[13] Mesfin, K., Tekle, G., and Tesfay, T., 2013, Ethnobotanical study of traditional medicinal plants used by indigenous people of Gemad District, Northern Ethiopia, J Med Plants Stud., 1 (4), 32–37.

[14] Lulekal, E., Asfaw, E., Kelbessa, E., and Van Damme, P., 2014, Ethnoveterinary plants of Ankober District, North Shewa Zone, Amhara Region, Ethiopia, J. Ethnobiol. Ethnomed., 10 (1), 21.

[15] Yirgu, A., and Chippaux, J.P., 2019, Ethnomedicinal plants used for snakebite treatments in Ethiopia: A comprehensive overview, J. Venomous Anim. Toxins Incl. Trop. Dis., 25, e20190017.

[16] Romha, G., Admasu, B., Gebrekidan, H.T., Aleme, H., and Gebru, G., 2018, Antibacterial activities of five medicinal plants in Ethiopia against some human and animal pathogens, Evidence-Based Complementary Altern. Med., 2018, 2950758.

[17] Lalitha, M.K., 2004, Manual on Antimicrobial Susceptibility Testing, Department of Microbiology, Christian Medical College, India.

[18] Njoku, O.V., and Obi, C., 2009, Phytochemical constituents of some selected medicinal plants, Afr. J. Pure Appl. Chem., 3 (11), 228–233.

[19] Ibrahim, H.A., and Ibrahim, H., 2009, Phytochemical screening and toxicity evaluation on the leaves of Argemone mexicana Linn. (Papaveraceae), Int. J. Appl. Sci., 3 (2), 39–43.

[20] Parekh, J., Chanda, S.V., 2007, In vitro antimicrobial activity and phytochemical analysis of some Indian medicinal plants. Turk. J. Biol., 31 (1), 53–58.

[21] Yousuf, S.K., Majeed, R., Ahmad, M., Sangwan, P.L., Purnima, B., Saxsena, A.K., Suri, K.A., Mukherjee, D., and Taneja, S.C., 2011, Ring A structural modified derivatives of withaferin A and the evaluation of their cytotoxic potential, Steroids, 76 (10-11), 1213–1222.

[22] Anonymous, 2004, Monograph: Withania somnifera, Altern. Med. Rev., 9 (2), 211–214.

[23] Rabhi, C., Arcile, G., Le Goff, G., Da Costa Noble, C., and Ouazzani, J., 2019, Neuroprotective effect of CR-777, a glutathione derivative of withaferin A, obtained through the bioconversion of Withania somnifera (L.) Dunal extract by the fungus Beauveria bassiana, Molecules, 24 (24), 4599.

DOI: https://doi.org/10.22146/ijc.74750