EVALUATION OF IN-VITRO SYNERGISTIC ANTIBACTERIAL ACTIVITY OF IMPATIENS TINCTORIA ABYSSINICA TUBER AND MOMORDICA FOETIDA SCHUMACH LEAVES AGAINST CLINICAL AND STANDARD PATHOGENIC BACTERIA

Abstract

Plant extracts have long constituted a natural source of antimicrobial compounds. Antimicrobial plant products have gained special interest because of the resistance to antibiotics that microorganisms have been acquiring. The present study aimed to evaluate the In-vitro synergistic antibacterial activity of Impatiens tinctoria subsp. Abyssinica and Momordica foetida schumach leave against some selected clinical and standard pathogenic bacteria. In this study methanol, chloroform, and acetone extract of I.tinctoria A. and M.foetida antimicrobial activity alone and synergistic effect were evaluated against three gram-negative bacteria E.coli (ATCC35218), P.aeruginosa (ATCC 27853), and S.typhimurium (ATCC 13331) and one gram-positive bacteria S. aureus (ATCC 43300) and the clinical isolates of S.aureus, and E. coli. The dried plant parts (tuber and leaves) extracted using the three solvents: Methanol, Acetone, and chloroform for 72 hr, and the agar well diffusion method used to test the plant parts for antibacterial activity. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were performed using two-fold broth dilution methods and then consequently done by agar culturing the MIC broth tubes that didn’t show bacterial growth. This investigation showed that the extracts of I.tinctoria, M.foetida alone, and their synergistic effect variously inhibited the growth of the test bacteria. The chloroform extraction synergistic effect recorded the maximum inhibition zone diameter 19.33±1.55 mm on S.typhimurium (ATCC 13331). There was no antibacterial activity in any plant extracts against clinical isolates E.coli. Extracts effectively inhibited tested bacterial growths as low as MIC values (15.6µg/ml). Lowest MBC values extracts were (31.25µg/ml).The gram-positive bacteria S.aureus (ATCC 43300) and the gram-negative bacteria S.typhimurium (ATCC 13331) were extracts that are more susceptible to all solvents. E.coli (clinical isolate) were more resistant and did not show any inhibition to all extracts in both plants. The synergistic activity of these two plant’s chloroform extract enhanced adjacent to the other solvent extracts. The overall antibacterial activity of acetone M.foetide leaves and I.tinctoria tuber was better in comparison to other solvent extracts. These plant extracts demonstrated may serve as a source for novel antibacterial drug discoveries. Further studies should be conducted on the antibacterial activities of both plants