Effects of mulberry leaf water extract on the metabolism of arachidonic acid in type 2 diabetes mellitus mice

To explore the preventive effects and potential mechanism of mulberry leaf water extract (MLWE) on type 2 diabetes mellitus (T2DM), this study observed the influence of MLWE on the metabolism of arachidonic acid (AA). T2DM mice were induced by high fat and high sucrose (HFHS) diet and intra-peritoneal injection of streptozotocin. The mice were randomly divided into a normal control group treated with drug-free solution (NC group), a normal control group treated with MLWE (NCML group), a diabetes mellitus (DM) group treated with drug-free solution (HFHS group), and a DM group treated with MLWE (HSML group); mice were maintained on this protocol for 10 weeks. Animal experimentation was approved by the Committee on the Ethics of Animal Experiments of Xuzhou Medical University. Mice livers and plasma were collected at the end of experiment. Fasting blood glucose (FBG) and fasting blood insulin (FBI) were detected by kits. The mRNA and protein expression levels of relative metabolic enzymes related to AA in mice livers were respectively detected by quantitative real time PCR (qPCR) and Western blot. The contents of AA and its relative metabolites in mice plasma were determined by liquid phase chromatography coupled with tandem mass spectrometry. The results showed that there was no significant variation for the relative expression of metabolic enzymes, contents of FBG, FBI, AA, and its relative metabolites between NCML group and NC group. Compared with NC group, the relative expression of fatty acid synthase (Fasn), phospholipase A2 (PLA2), cyclooxygenase-2 (COX-2), and lipoxygenase-5 (LOX-5), and the levels of FBG, FBI, AA, and its relative metabolites in DM group were obviously increased, while that of carnitine palmitoyltransferase 1A (CPT1A) and cytochrome P450 family 4A (CYP4A) were significantly decreased. After intervention with MLWE, those changes could be improved, indicating that MLWE could prevent T2DM by acting on AA metabolism.