MEDICINAL PLANTS AS A SOURCE OF BIOACTIVE COMPOUNDS

Abstract

This study investigates the phytochemical composition and antimicrobial activity of three widely used medicinal plants, Azadirachta indica, Ocimum sanctum, and Aloe vera, collected from southern Punjab, Pakistan. Methanolic extracts of the selected plants were prepared and analyzed for total phenolic content (TPC), total flavonoid content, and antibacterial activity against Escherichia coli and Staphylococcus aureus using the standard disc diffusion method. The results revealed significant variation in phytochemical composition among the plant species. Neem exhibited the highest total phenolic content (78.5 ± 3.2 mg GAE/g) and flavonoid concentration (42.6 ± 2.1 mg QE/g), followed by holy basil and Aloe vera. In antimicrobial assays, neem demonstrated the strongest inhibitory effect, with inhibition zones of 16.5 ± 0.9 mm against E. coli and 18.2 ± 1.1 mm against S. aureus. Statistical analysis confirmed significant differences among plant extracts (p < 0.05). A strong positive correlation (r = 0.82) was observed between phenolic content and antimicrobial activity. The findings confirm that medicinal plants are rich sources of bioactive compounds with strong therapeutic potential and may serve as promising candidates for the development of natural antimicrobial agents.