Screening and evaluation of potential bioactive compounds for antibacterial activity in Indian medicinal plants of Bacopa monnieri, Eclipta alba, Aegle marmelos and Centella asiatica

Abstract

The study was focused to identify and screening the potential action (antimicrobial activity) of ethanolic extract of the selected Indian medicinal plant leaves of Bacopa monnieri, Eclipta alba, Aegle marmelos, Centella asiatica against the following bacteria pathogenic isolates (Escherichia coli, Staphylococcus aureus, Klebsiella pneumonia, Enterococcus feceium , Enterobacter clocae , Pseudomonas aeruginosa and, Proteus mirabilis). Leaves of the above mentioned Indian medicinal plants were shade dried, powdered, and extracted using solvent ethanol. The potential ingredients present in these plants are associated to the bioactive components possessing antibacterial property. The analysis of antibiotic property was executed using disc diffusion method and to determine the minimum inhibitory concentration of the plant leaf extracts. The two methods used in this study was that in the (method-1 the, disc were dried with plant extract and in the method-2 the, disc were soaked in the plant extract). The plant leaf extracts with potential bioactive compounds were screened using wavelength scanning in the range of 200nm to 900nm by UV-VIS spectrophotometer and their characteristic peaks were detected. Among the two methods, method -1 was found to be the best antibiotic activity among the tested medicinal plants. The disc diffusion method revealed a high degree of activity against bacterial clinical isolates. The UV-VIS profile showed different peaks ranging from 270nm-740nm with different absorption. The spectral analysis of Eclipta alba, Bacopa monnieri, Aegle marmelos and Centella asiatica revealed the presence of bioactive components and were answerable for the antibiotic activity against selected pathogens. From the result Eclipta alba was observed to be the best antibiotic activity while compared to other three medicinal plants. The results confirmed that these plants extracts were potential as a source of drugs to combat infections caused by prone bacteria. Thus helps to further studies to identify functional bioactive compounds responsible for the in vivo antibacterial activity and possible mechanism of action of the extracts.