Antioxidative, antimicrobial and cytotoxic effects of the phenolics of Leea indica leaf extract

This study investigated the phytochemical, antioxidative, antimicrobial and cytotoxic effects of Leea indica leaf ethanol extract. Phytochemical values namely total phenolic and flavonoid contents, total antioxidant capacity, DPPH radical scavenging effect, FeCl3 reducing power, DMSO superoxide scavenging effect and Iron chelating effects were studied by established methods. Antibacterial, antifungal and cytotoxic effects were screened by disk diffusion technique, food poison technique and brine shrimp bioassay, respectively. Results showed the total phenolic content 24.00±0.81g GAE/100g, total flavonoid content 194.68±2.43g quercetin/100g and total antioxidant capacity 106.61±1.84g AA/100g dry extract. Significant (P<0.05) IC50 values compared to respective standards were recorded in DPPH radical scavenging (139.83±1.40μg/ml), FeCl3 reduction (16.48±0.64μg/ml), DMSO superoxide scavenging (676.08±5.80μg/ml) and Iron chelating (519.33±16.96μg/ml) methods. In antibacterial screening, the extract showed significant (P<0.05) zone of inhibitions compared to positive controls Ampicillin and Tetracycline against Gram positive Bacillus subtilis, Bacillus cereus, Bacillus megaterium, and Staphylococcus aureus and Gram negative Salmonella typhi, Salmonella paratyphi, Pseudomonas aeroginosa, Shigella dysenteriae, Vibrio cholerae, and Escherichia coli. Significant minimum inhibitory concentrations compared to tetracycline were obtained against the above organisms. In antifungal assay, the extract inhibited the growth of Aspergillus flavus, Candida albicans and Fusarium equisetii by 38.09±0.59, 22.58±2.22, and 22.58±2.22%, respectively. The extract showed a significant LC50 value compared to vincristine sulfate in cytotoxic assay. The results evidenced the potential antioxidative, antimicrobial and cytotoxic capacities of Leea inidica leaf extract to be processed for pharmaceutical use.