Asian Journal of Biology

This study investigated the antiproliferative and acute toxicity of the hydroethanolic extract of Smilax kraussiana using Allium cepa (onion) as a model, a very common plant in the Southern part of Nigeria, hence with unreported ethnomedicinal benefits. Phytochemical screening revealed the presence of bioactive compounds, including flavonoids, saponins, tannins, cardiac glycosides, steroids, and alkaloids, while anthraquinones were absent. Acute toxicity tests in mice yielded an LD₅₀ of 774.5 mg/kg, with severe toxicity observed at concentrations ≥1000 mg/kg. In the Allium cepa assay, the extract exhibited dose-dependent root growth inhibition, with near-complete suppression at 16 mg/ml, indicating potent phytotoxic (herbicidal) effects. Morphological changes, including root discoloration and reduced mitotic activity, were observed, with mitotic inhibition ranging from 7.29% (1 mg/ml) to 62.5% (16 mg/ml). Chromosomal aberrations and reduced cell division suggested genotoxic and antiproliferative properties, potentially linked to the bioactive compounds-mediated interference with cell signaling pathways. Thin-layer and column chromatography identified a steroidal component in the dichloromethane fraction, warranting further isolation. The results demonstrate the cytotoxic properties of S. kraussiana, reinforcing its ethnomedicinal applications while stressing the importance of controlled dosing given its toxicity at elevated levels. The observed antiproliferative activity indicates the potential ability of the plant extract to inhibit cell growth, which is a unique feature of anticancer agents, although additional in vivo research is necessary to confirm its safety profile and mode of action. These findings reveal the plant's dual functionality, thus serving as both a medicinal resource and a source of bioactive compounds with phytotoxic effects, offering valuable insights for pharmaceutical and agricultural applications.