Mulberry leaves supplementation alters lipid metabolism and promotes fatty acid ß oxidation in growing mutton sheep.

ABSTRACT

Mulberry leaves (MLs) are an unconventional feed with fiber and various active ingredients, and are acknowledged as likely to regulate lipid metabolism, while the molecular mechanism remains undefined. Therefore, our objective was to define the role of MLs on the overall lipid metabolism. We conducted a feeding experiment of three groups on growing mutton sheep fed with dried mulberry leaves (DMLs), with fermented mulberry leaves (FMLs), or without MLs (as control). Analyses of transcriptome and widely target lipids demonstrated the addition of MLs triggered big perturbations in genes and metabolites related to glycerolipid, phospholipid, ether lipid, and sphingolipid metabolism. Additionally, the variations of the above lipids in the treatment of MLs possibly facilitate immunity enhancement of growing mutton sheep via the activation of complement and coagulation cascades. Furthermore, treatments with MLs could expedite proceedings of lipid degradation and fatty acid ß oxidation in mitochondria, thereby to achieve the effect of lipid reduction. Besides, added DMLs also fuel fatty acid ß-oxidation in peroxisomes and own much stronger lipolysis than added FMLs, possibly attributed to high fiber content in DMLs. These findings establish the novel lipid-lowering role and immune protection of MLs, which lays the foundation for the medicinal application of MLs.

Mulberry leaves (MLs) are rich in a wide variety of active ingredients and are also a kind of traditional Chinese medicine with the same origin as medicine and food. Previous studies have found that MLs may regulate lipid metabolism. But the exact mechanism remains unclear. Our study reveals that ML supplement not only alters lipid metabolism including glycerol phospholipid, ether lipid as well as sphingolipid metabolism, which may help to improve immunity but also promote fatty acid degradation as well as ß oxidation to achieve the effect of fat reduction.