Immunomodulatory activity of mahanimbine from Murraya koenigii (Curry Leaf) on lipopolysaccharide-induced RAW 264.7 macrophages

Abstract

One of the kinds of carbazole alkaloids isolated from Murraya koenigii leaves is mahanimbine. Although this substance has the potential to be an immunotherapeutic agent such as immunostimulatory, antibacterial, antiviral and anticancer, however, its immunomodulatory effects have not yet been completely characterised. Mahanimbine's immunomodulatory effects on RAW 264.7 macrophages induced by lipopolysaccharide (LPS) were investigated in this research. Mahanimbine was applied to the RAW 264.7 macrophage cells for 24 hours, and the cell viability was assessed using the 3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) test. Using an ELISA detection assay, the production of IL-1β and TNF-α by stimulated RAW 264.7 cells was quantified. The substance had no cytotoxicity or effect on cell viability at any of the measured concentrations. In addition, mahanimbine did not demonstrate any changes in nitrite oxide production (14.06-15.40 μM) and IL-1β (251.0–238 pg/ml). However, the compound significantly enhanced the TNF-α production (344.4-426.0 pg/ml). The findings provide evidence of the immunomodulatory potential of mahanimbine by regulating pro-inflammatory cytokines.