Antioxidant, Anticancer and Antibacterial Activity of Withania somnifera Aqueous Root Extract
D. A. Barnes
School of Biomedical Sciences, University of Ulster, Coleraine, Cromore Road, Coleraine BT52 1SA, UK
R. Barlow
School of Biomedical Sciences, University of Ulster, Coleraine, Cromore Road, Coleraine BT52 1SA, UK
P. Singh Nigam
School of Biomedical Sciences, University of Ulster, Coleraine, Cromore Road, Coleraine BT52 1SA, UK
R. Owusu-Apenten *
School of Biomedical Sciences, University of Ulster, Coleraine, Cromore Road, Coleraine BT52 1SA, UK
*Author to whom correspondence should be addressed.
Abstract
Aims: To evaluate total antioxidant capacity, anticancer activity and antibacterial effects Withania somnifera aqueous-root extracts.
Study Design: In vitro study.
Place of Study: School of Biomedical Sciences, Ulster University, UK.
Methodology: Total antioxidant capacity (TAC) of whole powder and freeze dried W. somnifera aqueous-root extracts was determined using FRAP, DPPH, Folin and ABTS assays. Anticancer activity was accessed using MDA-MB-231 breast cells and Sulforhodamine B staining for cell viability. Antibacterial activity was by disk diffusion assay with penicillin, amoxicillin and streptomycin as positive controls.
Results: The TAC for W. somnifera extract was 86, 47, 195,or 443 gallic acid equivalents per 100g dry basis (mgGAE/ 100 g) using FRAP, DPPH, Folin or ABTS assays, respectively. Corresponding TAC values for freeze dried W. somnifera aqueous-root extract were, 418, 553, 1898 or, 1770 (mgGAE/100 g). W. somnifera aqueous-root extract inhibited MDA-MB-231 cell proliferation in a dose-dependent manner with IC50 = 0.19 mg/ml (21 µM GAE). Nil antibacterial effects were detected for freeze dried W. somnifera extract (0-1 mg/ml) across six species of bacteria tested.
Conclusion: Withania somnifera root water extract showed significant antioxidant and anticancer activity for MDA-MB-231 breast cancer cells but no antibacterial activity under the conditions of this study.
Keywords: Withania somnifera, antioxidant capacity, anticancer, antibacterial