Phytochemical Profiling, In Vitro Anticancer Activity, Molecular Docking and Topical Gel Formulation of Vigna unguiculata (L.) Walp. Leaf Extract

Breast cancer care needs affordable agents that act on several targets, and the leaf of cowpea (Vigna unguiculata (L.) Walp.), an edible legume, has rarely been tested against human tumour cells. Leaves were extracted sequentially with hexane, petroleum ether, ethanol and water, and the ethanolic extract (11.62% w/w) was studied further. It contained phenols, flavonoids and saponins, with a total flavonoid content of 11.07 mg quercetin equivalents/g and a total antioxidant capacity of 312.50 µg ascorbic acid equivalents/mg, but weak DPPH scavenging (IC50 678.2 µg/mL). LC-MS tentatively annotated 21 features. The extract reduced MCF-7 cell viability in a concentration-dependent manner (96.1% to 34.6% at 6.25-100 µg/mL after 24 h; IC50 59.52 µg/mL by interpolation and 46.59 µg/mL by logistic regression), raised intracellular oxidant load and, at 100 µg/mL, produced apoptotic nuclear morphology on acridine orange/ethidium bromide staining. Docking of five annotated constituents against AKT3 and ERK5 gave binding energies of -5.1 to -9.2 kcal/mol, with demethoxycurcumin and acacetin ranking highest. The extract (0.01% w/w) was formulated into Carbopol 934/HPMC K4M gels. The optimised gel (F4) had pH 6.86, viscosity 26,380 cP, spreadability 24.7 g.cm/s and drug content 99.1%, released 77.4% in 8 h by a Higuchi-type mechanism, and showed no incompatibility by FTIR. These in vitro and in silico findings do not establish selectivity, in vivo efficacy or skin permeation.