Saponin of Momordica cymbalaria Exhibits Anti‑Inflammatory Activity by Suppressing the Expression of Inflammatory Mediators in Lipopolysaccharide‑Stimulated RAW264.7 Macrophages

Background: Inflammation is an intricate biological process that commonly occurs in response to pathologic stimuli, and natural products have potential in healing inflammation. However, the anti‑inflammatory of Momordica cymbalaria is not evaluated yet. Objectives: The anti‑inflammatory mechanism of saponin of M. cymbalaria (SMC) was investigated in bacterial lipopolysaccharide (LPS)‑stimulated RAW264.7 mouse macrophage cell line. Materials and Methods: The cytotoxicity of SMC on RAW264.7 cells was determined by 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide assay at 500, 250, 125, 62.5, 31.25, 15.625, 7.812, 3.906, and 1.953 μg/mL. For anti‑inflammatory activity, RAW264.7 cells were stimulated with Escherichia coli LPS (1 μg/ml) in the presence or absence of SMC (50 μg/ml) for 16–24 h. Western blotting was carried to comprehend the expression of cyclooxygenase‑2 (COX‑2) and inducible nitric oxide (NO) synthase (iNOS) whereas expressions of the pro‑inflammatory cytokines (interleukin [IL]‑6, IL‑1β, and tumor necrosis factor‑alpha [TNF‑α]) and prostaglandin E2 (PGE2) were studied by enzyme‑linked immunosorbent assay (ELISA). NO production was estimated by Griess’s method. Salicylic acid, a nonsteroidal anti‑inflammatory drug, was used as a standard. Results: The saponin did not exert significant cytotoxicity on RAW264.7 cells. Western blot analysis revealed reduction in COX‑2 and iNOS expression on SMC treatment. Production of PGE2, IL‑6, IL‑1β, and TNF‑α was also found to be reduced when analyzed by ELISA. NO levels were also lowered. Conclusion: The findings suggest that the SMC possesses potential anti‑inflammatory activity by suppressing the expression of inflammatory mediators, COX‑2, iNOS, PGE2, and NO, and the cytokines in LPS‑stimulated RAW264.7 cells.