Antioxidant and Biological Activities of Mentha longifolia, L. Extracts

Abstract

Lamiaceae is one of the large plant families used to evaluate some secondary metabolites such as terpenoids and phenolic compounds. Mentha longifolia (M. longifolia ) is one of genus Mentha which includes 25 to 30 species. The plant was extracted with methanol to obtain methanol extract as crud extract. Methanol extract was fractionated with four different solvents graduated in polarity i.e pet ether, methylene chloride, ethyl acetate and butanol to obtain pet ether, methylene chloride, ethyl acetate and butanol fractions . The obtained methanol and its fractional extracts were tested for their total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity using scavenging activity of DPPH radical method. Antimicrobial activity of the plant methanolic extract against two Gram-positive bacterial isolates, two Gram-negative bacterial isolates, one isolate of yeast and one fungal isolate was performed. Results showed that the highest concentration of TPC was 228.36 mg GAE/g for ethyl acetate fraction, while the lowest one was observed for pet. ether fraction (154.56 mg GAE/g). On the other hand, TFC was ranged from 293.86 to 153.39 mg QE/g dw for pet. ether and butanol fractions, respectively. The highest antioxidant activity was found for ethyl acetate fraction i.e with lower IC50 = 107.01μg/ml.