Antimicrobial and Antioxidant Activity Analysis of Some Medicinal Plants of Bangladesh

Abstract

The antimicrobial potential of eight selected medicinal plants was evaluated against medically important thirteen pathogenic bacteria and three pathogenic fungi by using disc diffusion method. Moreover, the free radical scavenging activity was investigated for the development of anti-aging ingredient as a raw product for the cosmetic and other industries. Petroleum ether, ethyl acetate, methanol, butanol, n-hexane water extracts of medicinal plants were used for antimicrobial and anti-oxidant investigation. The rapid evaluation of antioxidant activity of different crude extracts of Pouzolzia zeylanica, Equisetum debile, Memecylon umbellatum, Datura metel, Cauroupeta guianensis, Andrographis paniculata were determined by using DPPH free radical method. The microbial inhibition zone ranged from 7-15 mm for different extracts of Andrographis paniculata where ethyl acetate extract showed highest microbial inhibition. The petroleum ether extract of D. metel gave 9-10 mm microbial inhibition except Pseudomonas aureus. Aloe vera gave 7-9 mm inhibition against microorganism by ethyl acetate extract. The methanol extract of A. paniculata showed inhibition only against two gram-positive and five gram-negative bacteria. The methanol extract of P. zeylanica, M. umbellatum and butanol (n-BuOH) extract of A. vasica also showed different range of antimicrobial activity. The N-hexane extract of A. vera and A. vasica and methanol extract of Equisetum debile did not show any antimicrobial activity. These extracts resulted in a rapid increase and decrease of the absorbance and showed different hydrogen-donating capacity towards the 2, 2'-diphenyl-1-picrylhydrazyl (DPPH) radical. A lot of differences found and showing anti-oxidant activity of different solvent extracts of different plant species. Among the species, ethyl acetate extract of E. debile, M. umbellatum, methanol extract of M. umbellatum, C. guianensis and n-BuOH extract of M. umbellatum, C. guianensis showed the maximum scavenging capacity of over 80.