Anti-b diminishes hyperlipidaemia and hepatic steatosis in hamsters and mice by suppressing the mTOR/PPARγ and mTOR/SREBP1 signalling pathways.

Background And Purpose: As a chronic metabolic syndrome, hyperlipidaemia is manifested as aberrantly elevated cholesterol and triglyceride (TG) levels, primarily attributed to disorders in lipid metabolism. Despite the promising outlook for hyperlipidaemia treatment, the need persists for the development of lipid-lowering agents with heightened efficiency and minimal toxicity. This investigation aims to elucidate the lipid-lowering effects and potential pharmacodynamic mechanisms of Anti-b, a novel low MW compound.

Experimental Approach: We employed high-fat diet (HFD) in hamsters and mice or oleic acid (OA) in cultures of HepG2 cells and LO2 cells to induce hyperlipidaemia models. We administered Anti-b to assess its therapeutic effects on dyslipidaemia and hepatic steatosis. We used western blotting, RNA sequencing, GO and KEGG analysis, oil red O staining, along with molecular docking and molecular dynamics simulation to elucidate the mechanisms underlying the effects of Anti-b.

Key Results: Anti-b exhibited a substantial reduction in HFD-induced elevation of blood lipids, liver weight to body weight ratio, liver diameter and hepatic fat accumulation. Moreover, Anti-b demonstrated therapeutic effects in alleviating total cholesterol (TC), TG levels, and lipid accumulation derived from OA in HepG2 cells and LO2 cells. Mechanistically, Anti-b selectively bound to the mTOR kinase protein and increased mTOR thermal stability, resulting in downregulation of phosphorylation level. Notably, Anti-b exerted anti-hyperlipidaemia effects by modulating PPARγ and SREBP1 signalling pathways and reducing the expression level of mSREBP1 and PPARγ proteins.

Conclusion And Implications: In conclusion, our study has provided initial data of a novel low MW compound, Anti-b, designed and synthesised to target mTOR protein directly. Our results indicate that Anti-b may represent a novel class of drugs for the treatment of hyperlipidemia and hepatic steatosis.