Investigation of antioxidant and antimicrobial effects of Plantago major leaves

Kaya, Özge
This study was designed to investigate Plantago major leaves, which is widely used in ethnobotanical uses in Turkey as is the case in all over the world, for their antioxidant capacities and antimicrobial effect on two gram-positive and two gramnegative bacteria. Extracts of P. major leaves prepared in the methanol and fraction samples were collected in solvents in increasing polarity, from non-polar to polar, to separate bioactive compound in crude extract. Antioxidant capacities of the crude extracts and fractions were examined by radical scavenging methods, namely 2,2-azinobis(3- ethylbenzothiazoline-6-sulfonic acid) ABTS and 1,1-diphenyl-2-picryl-hydrazyl (DPPH); as well, total phenolic and total flavonoid contents were determined. Furthermore, antimicrobial activities of crude extract and fractions were calculated in terms of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods together with disc diffusion method. v Among the investigated samples, ethyl acetate phase had the highest radical scavenging capacity with the ABTS value of 2130.4±9.845 μmol equivalents of trolox/ g of ethyl acetate fraction DW, and with EC50 value of 0.011±0.001 mg/mL; further, the highest phenolic content was found in ethyl acetate phase with values of 0.452 GAE mg/mg of ethyl acetate fraction DW and 0.434± 0.0017 mg catechin equivalent in per mg of ethyl acetate fraction DW. In general, it was found that the crude extract and aqueous phase of Plantago major had a weak antimicrobial effect on S. aureus, P.mirabilis, S.pyogenes and E. coli, along with the highest bacteriostatic and bactericidal upshot on selected bacterial populations in ethyl acetate fraction.
Citation Formats
Ö. Kaya, “Investigation of antioxidant and antimicrobial effects of Plantago major leaves,” M.S. - Master of Science, Middle East Technical University, 2011.