Studies on Antimicrobial Activity and Kinetics of Inhibition by Plant Products in India (1990-2016).

The antimicrobial activity of herbal extracts or plant isolates has usually been evaluated in India using different antimicrobial susceptibility testing methods generally based on diffusion and dilution. There are different analytical approaches for the reliable evaluation of antimicrobial activity ascribed to medicinal plants against selected pathogenic microorganisms. Obtained results may provide scientific bases for the selective use of these natural plants as healing drugs, crop-protecting pesticides, or shelf-life-extending solutions. In general, antimicrobial susceptibility methodologies involve in vivo and in vitro studies; at present, the in vitro evaluation of antibacterial activity appears more popular. Diffusion methods have some limitations, although they are extensively used to determine the susceptibility of organisms isolated from specimen samples to applied antimicrobials and vice versa. Dilution methods are preferred in the case of more precise antimicrobial activity estimation, in terms of minimum inhibitory concentration. With regard to the inherent antimicrobial nature of herbal compositions, herbs, and herbal extracts, Indian researchers have evaluated the reliability of these antimicrobial agents against selected pathogens and have shown them to be effective. Researchers have also tried to establish linear regression correlation analyses on the basis of available inhibition results. This research is still evolving, and interesting results may be expected in the future.