Cytotoxicity of Moringa leaf powder extracts on mammalian LTK and HEK293 cell lines

Abstract

Antimicrobial resistance (AMR) poses a major global health challenge, with projected mortality rates expected to surpass those of cancer by 2050. Moringa oleifera, a nutrient-rich medicinal plant, is traditionally valued for its antimicrobial and therapeutic effects, yet its cytotoxic impact on mammalian cells remains poorly characterised. This study aimed to evaluate the cytotoxicity of M. oleifera leaf extracts on non-cancerous mammalian cells. Leaves were processed via Soxhlet ethanol extraction, dimethyl sulfoxide (DMSO) steeping, and aqueous steeping. LTK fibroblast-like and HEK293 epithelial cell lines were exposed to graded concentrations of extracts. Cell viability was assessed using the MTT assay, and morphological changes were observed under phase-contrast microscopy. Results showed that extraction method and solvent significantly influenced cell responses. Ethanol Soxhlet extracts produced the strongest proliferative effects, enhancing viability up to 278% in HEK293 and 244% in LTK cells relative to controls. Water-steeped extracts supported moderate proliferation at higher concentrations (75 mg/mL), while DMSO-steeped extracts showed lower and more variable activity, particularly in HEK293 cells. Microscopy confirmed normal morphology in untreated controls, whereas water extract treatments at higher doses induced cell rounding, detachment, and reduced confluency. These findings suggest that M. oleifera extracts, particularly ethanol Soxhlet preparations, promote cell viability and exhibit a low cytotoxicity profile in non-cancerous mammalian cell lines. This effect is likely linked to the plant’s antioxidant and bioactive constituents. In conclusion, M. oleifera leaf extracts demonstrate potential for safe therapeutic use. Given the plant’s established antimicrobial properties, future studies should isolate bioactive compounds, assess selective activity against cancer cells, and optimise extraction methods. Such research could advance the development of safe, plant-derived agents to complement strategies addressing the global AMR crisis.