The Effects of Triterpenoid Saponins from the Seeds of Momordica cochinchinensis on Adipocyte Differentiation and Mature Adipocyte Inflammation

Obesity is a medical condition in which abnormal or excessive fat accumulates to an extent that is associated with various diseases. In our ongoing research to figure out natural products with anti-obesity effects, a phytochemical investigation of the EtOH extract of the seeds of Momordica cochinchinensis was carried out, which resulted in the isolation of two major triterpenoid saponins: gypsogenin 3-O-β-d-galactopyranosyl(1→2)-[α-l-rhamnopyranosyl (1→3)]-β-d-glucuronopyranoside (1) and quillaic acid 3-O-β-d-galactopyranosyl(1→2)-[α-l-rhamnopyranosyl(1→3)]-β-d-glucuronopyranoside (2). Then, the effects of the isolated triterpenoid saponins (1 and 2) on adipocyte differentiation were evaluated, and it was demonstrated that the isolated saponin (1) showed inhibitory effects on adipogenesis. In mature adipocytes, the isolated saponin (1) reversed tumor necrosis factor α (TNFα)-induced proinflammatory cytokine gene expression. Additionally, the isolated saponin (1) reduced lipolytic gene expression leading to decreased basal lipolysis activity. Collectively, these findings suggest that saponin (1) of M. cochinchinensis exerts beneficial effects in the regulation of adipogenesis and adipocyte inflammation and could be a potential therapeutic alternative in the treatment of obesity-induced metabolic diseases.

Keywords: Momordica cochinchinensis; Saponin; adipocyte; diabetes; obesity.