Antioxidant, Cytotoxic, and Antimicrobial Activities of Pterocarpus santalinus Leaves

This study evaluates the chemical and biological properties of Pterocarpus santalinus leaf methanolic extract to establish its scientific basis for potential therapeutic applications. The phytochemical analysis revealed the presence of 595.04 mg/g flavonoids (quercetin equivalent) and 69 mg/g phenolic compounds (gallic acid equivalent), underscoring its antioxidant potential. The extract exhibited DPPH radical scavenging activity with an IC50 of 337.79 µg/ml, indicating moderate antioxidant capacity. Additionally, mild antimicrobial activity was observed against Escherichia coli and Aspergillus niger. The cytotoxic effects of the extract were assessed in HeLa cells, demonstrating a concentration-dependent relationship. At concentrations of 100 µg/ml and 200 µg/ml, cell viability remained above 95%, indicating non-toxic effects. However, at 500 µg/ml, a significant decrease in cell viability to 20-30% was observed, with an LC50 value of 365.77 µg/ml, indicating substantial cytotoxicity at higher concentrations. These results suggest that while lower concentrations are safe, higher doses may induce cell death, necessitating the establishment of safe dosage ranges for therapeutic applications. The findings support the pharmacological potential of P. santalinus leaf extract, highlighting its relevance in antioxidant, antimicrobial, and anticancer research, and warrant further investigation to refine its medicinal applications.