Effect and Mechanism of Loquat Leaf Extract Combined with Exercise on Lipid Metabolism in High-Fat Diet Induced Mice

In order to study the effect of loquat leaf extract (LLE) combined with exercise (Ex) on lipid metabolism, mice were divided into normal diet group, high-fat diet group, Ex intervention group, LLE intervention group and LLE-Ex intervention group. After 13 weeks, the body weight changes, organ indices, serum and organ lipid levels, oxidative stress status, protein expression of lipid metabolism and oxidative stress signaling pathways, and serum metabolomic differences of mice were analyzed. The results showed that LLE-Ex could significantly inhibit the body weight gain, lower the adipose tissue proportion in the body, which decreased the index of liver by 8.1%, that of epididymal fat by 22.9%, and that of abdominal fat by 54.0%. It significantly regulated the serum TG, HDL-C and LDL-C levels, and decreased the levels of serum TG and LDL-C by 47.1% and 28.5% respectively, and increased HDL-C levels by 26.2%. It also significantly prevented the deposition of hepatic free fatty acid (FFA) and muscular TG, TC, FFA, and decreased the levels of hepatic FFA and muscular TG, TC and FFA by 41.0%, 13.4%, 36.4%, and 34.9%, respectively. It also improved the level of oxidative stress status in skeletal muscle by decreasing MDA levels at skeletal muscle by 19.5% and increasing CAT activity by 11.5%. The observed effects of LLE-Ex were more comprehensive and marked than LLE or Ex alone, and probably achieved by modulating the AMPK and Nrf2-HO1 signaling pathways and affecting D-glutamine and D-glutamate metabolism, alanine, aspartate and glutamate metabolism and sphingolipid metabolism.