CHEMICAL PROFILING, ANTIOXIDANT ACTIVITY, AND CYTOTOXIC EFFECTS OF DENDROCNIDE MEYENIANA (ALINGATONG) LEAF EXTRACT

Abstract

Objective: This study aimed to characterize the phytochemical composition of the methanolic leaf extract of Dendrocnide meyeniana (Alingatong) and to determine whether the biological activities reported for its identified constituents are reflected in the antioxidant and cytotoxic properties of the crude extract. Methods: Gas chromatography-mass spectrometry (GC-MS) analysis was performed to identify the phytochemical constituents of the plant extract. The reported biological activities of the identified compounds were subsequently examined through published literature. Based on the presence of compounds previously associated with antioxidant and anticancer activities, antioxidant capacity was evaluated using the 2,2-diphenyl-1- picrylhydrazyl (DPPH) radical scavenging assay, while cytotoxic effects were assessed against MIA PaCa-2, AGS, 4T1, and WM-266-4 cancer cell lines, as well as HF16 normal fibroblast cells. Half-maximal inhibitory concentration (IC50) and selectivity index (SI) values were determined to evaluate cytotoxic potency and selectivity. Results: GC-MS analysis identified 76 phytochemical constituents, predominantly alkanes, together with fatty acid methyl esters, terpenoids, and phenolic compounds. The extract demonstrated concentration-dependent DPPH radical scavenging activity (EC50=1096.17 μg/mL), although substantially weaker than ascorbic acid (EC50=7.83 μg/mL). Cytotoxicity assays revealed concentration-dependent reductions in cell viability across all tested cancer cell lines, with IC50 values ranging from 134.64±3.48 to 165.26±8.46 μg/mL. WM-266-4 melanoma cells exhibited the greatest sensitivity and highest selectivity toward the extract, with an IC50 value of 134.64±3.48 μg/mL and an SI of 1.23. Overall, selectivity indices ranged from 1.00 to 1.23, indicating limited selectivity relative to HF16 normal fibroblasts. Conclusion: The antioxidant and cytotoxic activities observed in the methanolic leaf extract of D. meyeniana are consistent with the reported biological properties of several compounds identified through GC-MS analysis. Although the extract exhibited limited selectivity toward cancer cells, its pronounced activity against WM-266-4 melanoma cells highlights its potential as a source of bioactive compounds for further pharmacological investigation and mechanistic studies.