Evaluation of Antioxidant and Antimicrobial Activities of Certain Cassia Species

The aim of this study was to evaluate the antioxidant and antimicrobial activities of the defatted methanol extracts of Cassia glauca, C.fistula, C.didymobotry, C.sophera, C.occidentalis, C.grandis and C.nodosa. Dot-blot and DPPH staining, reducing power and total antioxidant capacity were used for determination of antioxidant activity of the tested extracts. Results exhibited that, the defatted methanol extracts of the tested Cassia species demonstrated varying degrees of antioxidant activity with different antioxidant models and C.glauca was the most active plant. The antioxidant activity of the defatted methanol extract of C.glauca increased with increasing of the temperature and acidic pH whereas it decreased by storage. The antimicrobial screening was carried out by using disc diffusion method toward certain bacteria and fungi strains. C.glauca, C.occidentalis, C.fistula, C.didymobotrya, and C.sophera extracts exhibited variable antimicrobial activity whereas the methanol extracts of C.grandis and C.occidentalis did not show any activity. The methanol extract of C.glauca was also the most active. Owing to the high antioxidant and antibacterial activities of the defatted methanolic extract of C.glauca, this extract was fractionated using different organic solvents; chloroform, ethyl acetate and n-butanol and these fractions were tested as antioxidant and antimicrobial agents. The ethyl acetate and n-butanol fractions exhibited high activities.