Alleviation of Lipid Accumulation in <i>Caenorhabditis Elegans</i> by <i>Toona Sinensis</i> Flower Extracts

Ethnopharmacological relevanceSome people in southern China often drink water made from Toona sinensis flower to alleviate fatigue and assist in lipid and glucose reduction. However, the material basis and potential mechanism of the lipid-lowering effect of Toona sinensis flower are not clear.Materials and methodsThe major components were extracted from Toona sinensis flower and compounds were identified using UPLC-MS/MS assay. In vitro experiments were conducted to determine the ability of Toona sinensis flower extract (ETF) to inhibit digestive enzyme activity. Caenorhabditis elegans were used as experimental animals to determine the effect of ETF in preventing and alleviating fat deposition by oil red O staining test and triglyceride level assay, and the effect of ETF on energy metabolism was verified by the determination of body size, locomotor ability, pharyngeal pump movement, and growth rate. Finally, qPCR technique and administration of gene-deficient mutants were applied to explore the signaling pathways involved in the reduction of fat deposition by ETF.ResultsThe main components in ETF are polyphenols and flavonoids, which have significant lipid-lowering ability in both normal and high-fat nematodes, and have preventive and mitigating effects on fat deposition. At the same time, ETF-mediated fat reduction involved neither energy intake nor energy expenditure. In in vitro experiments, ETF showed the ability to inhibit digestive enzyme activity close to that of a positive drug.ETF likely relies on the modulation of pathways such as MUFA biosynthesis by SBP-1/SREBP, DAF-16/FOX signalling pathways to reduce fat deposition.ConclusionThis study demonstrates the efficacy of ETF in preventing obesity and preliminarily explores the mechanism of action, and these findings suggest the potential application of ETFs in healthcare.