Evaluation of antibacterial and antioxidant potential of Euphorbia cotinifolia linn. leaf extracts

Abstract

Antibacterial activity of aqueous and solvent extracts of E. cotinifolia leaves were tested against some human pathogenic bacteria viz. Escherichia coli, Klebsiella pneumonia, Bacillus subtilis, Bacillus cereus, Salmonella typhi, Enterobacter aerogenes and Staphylococcus aureus by agar cup diffusion and broth microdilution methods. Antioxidant properties were evaluated for different solvent extracts by diphenyl picryl hydrazyl (DPPH), nitric oxide (NO) and hydrogen peroxide methods and IC50 values were calculated and compared with the standard ascorbic acid and butylated hydroxyanisole. Among the aqueous and organic solvent extracts, methanol and ethyl acetate, showed significant activity against B. subtilis and E. aerogenes which recorded a maximum inhibition zone of 17.25 mm. Minimum inhibitory concentration of methanol and ethyl acetate extracts for different bacteria ranged from 0.3- 1.25 mg/mL. In DPPH method, IC50 values of chloroform, petroleum ether, ethyl acetate and methanol were found to be 15, 17, 18 and 19 mg/mL, respectively, lesser than the standard, ascorbic acid (25 mg/mL). Phytochemical analysis of aqueous, ethyl acetate and methanol extract showed the presence of flavonoids, terpenoids, tannins and steroids. Further work is in progress to isolate the active compound(s).

Keywords

• E. cotinifolia
• antibacterial activity
• antioxidant activity
• flavonoids
• steroids