Zexie decoction reduce glucose-dependent lipid accumulation and oxidative stress in Caenorhabditis elegans

Obesity has become a global public health problem. Zexie decoction (ZXT) is a classic formula from Synopsis of the Golden Chamber. However, the long-term effect of ZXT in lipid accumulation remain unclear. This study aims to investigate the effect of ZXT on aging, lipid metabolism and oxidative stress. Different concentration of ZXT was administered to Caenorhabditis elegans (C. elegans) cultured in NGM or the high glucose nematode growth media (GNGM). The lifespan, heat stress resistance, lipid accumulation and related mRNA expression of the worms were examined. Oil Red staining and triglyceride were used to evaluated the lipid accumulation. Nhr-49, fat-5/fat-7, fat-5/fat-6 or skn-1 knockout mutants were used to clarify the effect on lipid metabolism of ZXT. GFP-binding mutants were used to observe the changes in protein expression. ZXT improved the survival rate of C. elegans in lifespan test and heat stress test. ZXT also reduced lipid accumulation in C. elegans and significantly changed the expression of fatty acid synthesis related genes and lipid metabolism related genes. In addition, ZXT-treated C. elegans showed a higher expression of anti-oxidative protein, and reduced the expression of oxidative stress and mitochondrial dysfunction marker. However, when skn-1 was knockdown, ZXT no longer had the effect of maintaining the mitochondria membrane potential and lipid lowering but still effectively decreased the O2·− induced by high glucose. ZXT reduced fat accumulation by regulating lipid metabolism via multiple targets and enhanced stress resistance by its antioxidant effect in C. elegans.