The effect of extracts of Tulbaghia violacea on the proliferation of a murine macrophage cell line

Abstract

Tulbaghia violacea Harv. (wild garlic) has been used in traditional medicine in Southern Africa for the treatment of various ailments. However, there is contradictory evidence regarding the safety and toxicity of the plant. This study investigated the effects of crude water and ethanol extracts from T. violacea on the proliferation of a macrophage cell line in vitro. Water and ethanol extracts were prepared from the leaves, stems and roots of T. violacea. A 23 factorial design was used to investigate the effects of the crude extracts on the proliferation of a macrophage cell line. The factorial design consisted of three independent variables (concentration of the crude extract, duration of stimulation with the crude extract and nature of the solvent used to prepare the crude extract) at either a high or a low level. The proliferation of the macrophages was determined using the MTT assay as well as microscopy. The results showed that crude ethanol extracts significantly (p < 0.001) inhibited the proliferation of the macrophages in comparison to the crude water extracts. Only high concentrations of the crude water extracts produced a significant (p < 0.001) reduction in proliferation of the macrophages. The crude water extracts from the leaves were significantly (p < 0.001) less cytotoxic whereas those prepared from the stem where highly cytotoxic. Preparation and usage of herbal remedies from T. violacea should be done with caution and must consider the concentration, nature of extract, as well as part of the plant used.