Immunomodulatory effects of crude acetone and water leaf extracts from Tulbaghia violacea on RAW۲۶۴.۷ cells stimulated with lipopolysaccharide (LPS)

Introduction: Tulbaghia violacea is a medicinal plant used in traditional healing practices in South Africa. This study sought to investigate if water and acetone extracts from T. violacea impact immunomodulation by influencing the production of cytokines and nitric oxide (NO) in macrophages stimulated by lipopolysaccharide (LPS). Methods: The ۳-(۴, ۵-dimethylthiazolyl-۲)-۲, ۵-diphenyltetrazolium bromide (MTT) assay was performed to examine the toxicity of acetone and aqueous extracts from T. violacea on RAW۲۶۴.۷ cells treated with LPS over ۲۴ hours. The effect of NO production in treated cells was examined using a Greiss assay, while cytokine levels were determined using a Luminex assay. Results: The viability of RAW۲۶۴.۷ cells remained higher than ۸۰% after exposure to ۵۰ µg/mL or lower concentrations of both water and acetone extracts. The acetone extract showed potent inhibitory effects on NO production at ۵۰ µg/mL and increased pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin-۱a (IL-۱α), and interleukin-۶ (IL-۶) but did not significantly affect interleukin-۱beta (IL-۱β). The water extract significantly increased IL-۴ levels (P<۰.۰۵) at ۴۸ hours. Both extracts increased granulocyte-colony stimulating factor (GCSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma-induced protein ۱۰ (IP۱۰), macrophage inflammatory protein-۱ alpha and beta (MIP-۱α and MIP-۱β), monocyte chemoattractant protein-۱ (MCP-۱), macrophage inflammatory protein-۲ (MIP-۲), and regulated upon activation, normal T cell expressed and secreted RANTES levels to over ۱۰ ۰۰۰ pg/mL. Conclusion: Both extracts from T. violacea possess immunomodulatory activities on LPS-stimulated RAW۲۶۴.۷ cells. Further studies should determine their toxicities and suitability as alternatives to synthetic counterparts.