Evaluation of Medicinal Plant Extracts As Potential Β-Lactamase Inhibitors by Studying Their Synergistic Effect with Β-Lactam Antibiotics to Combat Antibiotic Resistance

Abstract Antibiotic resistance via β-lactamase production is a major threat to worldwide healthcare and underscores the necessity of alternative therapeutic approaches. This research presents a novel approach by assessing the synergistic activity of medicinal plant extracts with β-lactam antibiotics to identify natural β-lactamase inhibitors. Methanolic extracts of Tinospora cordifolia (Giloy) and Calotropis gigantea (Milkweed) and aqueous extracts of six other medicinal plants, i.e., Garcinia indica (Kokum), Couroupita guianensis (Kailaspati), Bryophyllum pinnatum (Bryophyllum), Camellia sinensis (Green Tea), Carica papaya (Papaya), and Trachyspermum ammi (Ajwain) were screened against Klebsiella pneumoniae and Escherichia coli. Different in vitro Antibiotic susceptibility tests were performed to find out the zones of inhibition (ZOI). Of the extracts that were tested, Garcinia indica and Tinospora cordifolia showed considerable inhibition of Klebsiella pneumoniae and showed synergy with Penicillin as a beta lactam antibiotic, suggesting the presence of possible β-lactamase inhibitors. Phytochemical analysis indicated the presence of alkaloids, phenols, flavonoids and tannins in the extracts, which are known to possess antimicrobial and enzyme-inhibitory activity. These results indicate that such a synergy between the plant extracts and the β-lactam antibiotics could potentially increase the inhibition of bacteria, providing a natural solution against β-lactamase-associated resistance. Further compound isolation and β-lactamase inhibition assays are required to prove these observations.