Stanley Mukanganyama
University of Zimbabwe, Zimbabwe
Title: Exploring mechanisms of antimicrobial action of extracts and phytochemicals isolated from medicinal plants from Zimbabwe
Biography
Biography: Stanley Mukanganyama
Abstract
The World Health Organization suggests that medicinal plants are the best source of obtaining a variety of drugs, therefore, there is need for better understanding of their properties, efficacy and safety. Humans are afflicted with many microbial pathogens that include bacteria, fungi and mycobacteria. However, due to the abuse of antimicrobial agents, most microbes have developed resistance. Plant species used by herbalists might be used as alternative sources of novel antimicrobial agents. Our research focus has been to study the effects of plant extracts and or their pure constituents on the growth of bacteria, fungi and mycobacteria. Chief to our investigations was the need to determine the mechanism by which herbal medicines and their phytochemicals work at a molecular level. Our results show that many of the plant derived compounds work by interfering with cell membrane integrity and this results in protein leakage or nucleotide leakage from the cells of pathogens. Some of the extracts work by interfering with transport across the membrane where the efflux of compounds from the inside to the outside is blocked. It was also noted that other phytochemicals targeted the virulence factors of the microbial species and these included inhibition of excretion of exo-enzymes such as phospholipases and proteases. Bacterial biofilms are structured communities of bacterial cells embedded within a self – produced matrix. Our results also show that disruption of biofilm formation is another mechanisms by which phytochemicals work. Phytochemicals that exhibit multiple mechanisms of actions and novel mechanisms of action need to be identified.