Antibacterial activity of plant extract

Abstract

The increasing resistance of pathogenic bacteria to synthetic antibiotics has intensified the search for natural alternatives, with plant extracts emerging as promising antibacterial agents. Plants are a rich source of bioactive compounds such as alkaloids, flavonoids, tannins, terpenoids, phenolics, and saponins, which have been reported to inhibit the growth of both Gram-positive and Gram-negative bacteria. These compounds act through various mechanisms, including disruption of bacterial cell walls, inhibition of protein synthesis, interference with nucleic acids, and suppression of quorum sensing. Several studies have shown that extracts from medicinal plants like Azadirachta indica, Allium sativum, Curcuma longa, and Ocimum sanctum exhibit strong antibacterial activity against clinical pathogens such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Solvent polarity plays a significant role in extracting phytochemicals, with ethanol, methanol, and aqueous extracts often yielding different levels of antibacterial activity. Furthermore, the synergistic use of plant extracts with conventional antibiotics has been reported to enhance efficacy, reduce side effects, and minimize the development of resistance. These findings highlight the potential of plant-based antimicrobials as cost-effective, safe, and eco-friendly alternatives in treating infectious diseases. Continued research is required to isolate, characterize, and standardize active compounds for clinical use. The integration of traditional medicinal knowledge with modern pharmacological approaches may lead to the discovery of novel antibacterial drugs that can combat multidrug-resistant pathogens and improve global healthcare.