In-vitro Antimicrobial Activities of Different Extracts of Grapevine Leaves (Vitis vinifera L.) from West Anatolia against some Pathogenic Microorganisms

Abstract

The extract of ethanol, methanol, aqueous grapevine leaves (Vitis vinifera L.) were screened in vitro for their antimicrobial activity against Gram-positive, Gram-negative bacteria and one yeast. Disk diffusion method was used for antimicrobial activity of extracts and the microwell dilution assay was used for determination of minimal inhibitory concentration (MIC) of each extract. Ethanolic extracts of grapevine leaves showed various antimicrobial activity (0-25 20 mu L-1 inhibition zone) to the microorganisms tested. The methanolic extracts showed antimicrobial activity (0-16 2041 inhibition zone) to the microorganisms tested. The aqueous extracts showed no inhibition zone five out of ten microorganisms. The ethanolic extract displayed the best activity (MIC 6.25 mu g/ml) against S. typhimurium CCM 583. Other microorganisms (S. aureus ATCC 6538/P, P. aeruginosa ATCC 27853, K. pneumoniae CCM 2318, C. albicans ATCC 10239) were showed between MIC 12.5-200 mu g/ml. The methanolic and aqueous extracts were between MIC 50-400 mu g/ml and between MIC 100-400< mu g/ml, respectively. In the study, chemical composition of ethanolic grapevine leaves extract was analysed by GC/MS analysis. The GC/MS analyses allowed 15 compounds to be determined; the main constituents of the grapevine leaves extract were ethanol (91.82), cyclotrisiloxanehexamethyl (1.25 %) and diethoxydimethylsilane (1.14 %). The results of the present in vitro work indicate that grapevine leaves extracts, especially ethanolic, could be used as natural antimicrobial agents in the food preservation and human health for microorganisms.