Studies on Antioxidant and Antimicrobial Activities of Pajanelia longifolia (Willd.) Schuman

Abstract

In the present study total polyphenols, antioxidants and antimicrobial activities of the bark powder extracts of Pajanelia longifolia in water, ethanol, methanol and ethyl acetate were estimated and analysed. Soxhlet method was employed for preparation of bark extracts in different solvents. FRAP assay was used to determine the total antioxidant activity and phenols were estimated by FC assay. Antibacterial and antifungal activity studied by well diffusion method. Water and methanolic extract had the highest amount of polyphenols (28.51 and 25.62 mg pyrocatechol equivalent/g raw material respectively) followed by ethanol and ethyl acetate extracts. Among the four extracts, 70% methanol extract showed the maximum antioxidant activity while ethyl acetate extract exhibited the minimum. Antibacterial activity of the extracts was tested against 7 bacterial species such as Staphylococcus aureus, Vibrio parahaemolyticus, Escherichia coli, Bacillus subtilis, Proteus mirabilis, Lactobacillus casei and L. fermentum. Vibrio parahaemolyticus and Bacillus subtilis were found to be susceptible to the ethanolic extracts at a concentration of 5 mg/ml. Other bacterial species including E. coli was found to be the most resistant organism and was not inhibited by any of the extracts. The present study showed that Pajanelia longifolia has significant levels of antioxidant and antimicrobial activity against a V. parahaemolyticus and Bacillus subtilis. The present study is the first scientific report in the literature to show the presence of antioxidant and antimicrobial activity of the said plant. Therefore the result strengthens the existing traditional usage of the plant for the therapeutic use.