Lipidomics reveals the lipid-lowering and hepatoprotective effects of Celosia Semen on high-fat diet-induced NAFLD mice

Ethnopharmacological relevance: Celosia Semen (CS) serves as a traditional Chinese medicine (TCM) for promoting liver health and enhancing vision, with extensive clinical applications. Triterpenoid saponins represent the primary active components of CS, with the highest concentration of Celosin I (CI) detected. The urgent need for effective NAFLD treatments motivated us assess the beneficial effects of total saponins from CS (TSCS) and CI.

Aims of the study: To investigate the therapeutic effects of TSCS and CI on NAFLD and its underlying molecular mechanisms.

Materials and methods: The impact of TSCS and CI on NAFLD was evaluated through in vitro and in vivo methodologies, utilizing high-fat diet (HFD) and palmitic acid/oleic acid modeling on C57BL/6J mice and AML12 cells, respectively. Biochemical analysis, H&E and Oil red O staining were used to characterize the lipid-lowering and hepatoprotective activities of TSCS and CI. Lipidomics discerned the impact of TSCS and CI interventions on liver lipid composition, distribution and alteration in NFALD mice. RT-qPCR and western blotting detected the influence of TSCS and CI on genes linked to de novo lipogenesis, fat calculation uptake, oxidation and esterification. The docking analysis anticipated the interaction of six major triterpenoid saponins within TSCS with SREBP1.

Results: TSCS and CI markedly diminished lipid accumulation induced by high fat both in vivo and in vitro. TSCS and CI also mitigated hepatic steatosis and liver injury induced by HFD through the reduction of TC, TG, FAs, ALT, and AST, even at minimal dose of 25 mg/kg. Lipidomics indicated that TSCS and CI had the potential to modulate the lipid metabolism network, rectify lipid metabolic dysregulation induced by NAFLD, decrease the levels of harmful lipids, and elevate the levels of advantageous lipids. Furthermore, TSCS and CI exhibited a strong affinity to SREBP1, thereby might directly influence the expression of SREBP1 and a cascade of essential enzymes involved in de novo lipogenesis, and finally resulting in a diminished synthesis of novel lipids.

Conclusion: TSCS and CI were confirmed firstly as key active components of CS in amending hepatic steatosis and mitigate liver damage in NAFLD, outlining the preliminary mechanism. They warrant further exploration as drug candidates for NAFLD treatment, especially in light of the current shortage of medications and limited therapeutic options.