Selective anticancer activity of Vachellia nilotica fruit extract: integrated phytochemistry with antioxidant,...

Vachellia nilotica has long been employed in traditional medicine for its therapeutic value. This study aimed to assess the phytochemical composition, antioxidant potential, antimicrobial efficacy, and in vitro anticancer activity of its methanolic fruit extract, thereby validating its ethnopharmacological significance.

The methanolic extract was subjected to preliminary phytochemical screening for key secondary metabolites. Total phenolic and flavonoid contents were quantified using Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. The antioxidant capacity was evaluated through the DPPH free radical scavenging assay. Antibacterial and antifungal activities were determined by the agar well diffusion method against pathogenic strains. The cytotoxic and selectivity profiles were assessed using MTT assays on human cancer cell lines (MCF-7, PC-3, Caco-2) and normal Vero cells, with doxorubicin serving as a positive control.

Qualitative screening revealed the presence of tannins, alkaloids, glycosides, flavonoids, and terpenoids. The extract exhibited strong antioxidant potential with an IC₅₀ of 31.77 μg mL^-1, supported by high total phenolic (419.45 mg GAE g^-1) and flavonoid (245.48 mg QE g^-1) contents. Notable antibacterial effects were observed against both Gram-positive and Gram-negative bacteria, with maximum inhibition zones of 23.00 mm for Acinetobacter johnsonii and 21.00 mm for Serratia marcescens at 1000 μg mL^-1. Pronounced antifungal inhibition was recorded against Rhizoctonia solani, Penicillium italicum, and Fusarium oxysporum. The extract exhibited moderate and selective cytotoxicity toward cancer cells, reducing viability to below 5% at 500-1000 μg mL^-1, while maintaining significantly higher viability in normal Vero cells compared with doxorubicin.

The findings underscore the potent antioxidant, antimicrobial, and selective anticancer properties of V. nilotica fruit extract. These bioactivities substantiate its traditional medicinal applications and highlight its potential as a source of bioactive compounds for therapeutic development. Further in vivo and mechanistic studies are warranted to elucidate its pharmacological potential and clinical relevance.