Sweet pepper extract reduces fat storage in Caenorhabditis elegans by SREBP-SCD axis based on multiomics analysis

Sweet pepper, a globally commercialized horticultural crop, has been demonstrated to impede fat accumulation, but its mechanism remains incompletely understood. This study was designed to explore the potential mechanism of sweet pepper in reducing fat accumulation in Caenorhabditis elegans through RNA-seq and metabolome analysis. A total of 22 metabolites were identified from sweet pepper by UHPLC-ESI-TOF-MS analysis. In vivo, sweet pepper significantly inhibited α-glucosidase activity and reduced the levels of glucose, triglycerides (TG), total cholesterol (TC), and the area stained with oil red O. Additionally, it increased body length and the number of head swings in C. elegans compared to the control group. The KEGG enrichment analysis revealed significant enrichment of the biosynthesis of unsaturated fatty acids signaling pathway among the differentially expressed genes and metabolites. Furthermore, the mRNA levels of sterol regulatory element-binding proteins (SREBPs) ortholog SBP-1, as well as the stearyl CoA desaturase-1 (SCD1), including fat-5, fat-6, and fat-7, were significantly decreased after treatment with sweet pepper. Collectively, sweet pepper effectively reduces fat accumulation, which is probably related to downregulating the SREBP-SCD axis, offering new insights for future functional food development.