Effect of extraction methods on yield, phytochemical constituents, antibacterial and antifungal activity of Capsicum frutescens L.

Abstract

Capsicum frutescens L. (Family Solanaceae) commonly used to make one of the most common spice, red peppers is also associated with multiple health benefits. In the present study, extract yield and phytochemical constituents of n-hexane, chloroform, ethyl acetate, acetone and methanol extracts of dried seeds of C. frutescens L. prepared by microwave assisted solvent extraction technique, also known as “Green extraction” were compared with the solvent extracts prepared by two common conventional extraction methods. In vitro antibacterial and antifungal activity of all extracts were determined by using agar well diffusion method against three gram positive bacteria (Bacillus cereus, Staphylococcus aureus and S. aureus MRSA), five gram negative bacteria (Escherechia coli, Salmonella typhi, Pseudomonas aeruginosa, Klebsiella pneumoniae and Proteus vulgaris) and two fungi (Candida albicans and C. krusei). Results were also compared with positive (Cotrimoxazole and Nystatin) and negative controls (Dimethyl sulphoxide). Solvent extracts prepared by microwave assisted method showed significant activity and n-hexane extract formed inhibition zone of 14.4 mm against P. aeruginosa, 20.0 mm against C. albicans, while ethyl acetate extract formed largest inhibition zone (15.0 mm) against C. krusei. Minimum inhibitory concentration evaluated by two fold serial broth tube dilution method ranged between 0.312 to 5 mg/mL.