ANTIMICROBIAL EFFECTS OF ETHANOLIC EXTRACTS OF NEEM (AZADIRACTA INDICA A.) LEAVES AND STEM BARK.

This study investigated the phytochemical composition and antimicrobial efficacy of ethanolic extracts from neem (Azadirachta indica) leaves and stem bark against Staphylococcus aureus (bacterium) and Aspergillus niger (fungus). Phytochemical analysis revealed distinct profiles: leaves contained alkaloids, tannins, saponins, and steroids, while stem bark contained alkaloids, flavonoids, and saponins. Antimicrobial assays demonstrated that both extracts were effective, but stem bark extract was significantly more potent. Notably, the stem bark extract at 100 mg/mL exhibited superior activity against S. aureus, producing a larger zone of inhibition (30.00 mm) than the Control control (27.00 mm). Minimum Inhibitory Concentration (MIC) results confirmed the stem bark's greater potency, showing lower MIC values for both test organisms. The study concludes that neem stem bark is a highly effective antimicrobial source, with its efficacy being dependent on the specific plant part and extract concentration, highlighting its potential as a natural alternative to conventional antibiotics. Clinical Applications: Given its superior efficacy against S. aureus, neem stem bark extract at 100 mg/ml should be further investigated for developing topical antimicrobial formulations or complementary therapies for bacterial infections. Agricultural and Preservation Uses: Given its antifungal properties, neem stem bark extract could be explored as a natural preservative in food and agricultural products to combat fungal contaminants like A. niger.