Diaphragma juglandis extracts modifies the gut microbiota during prevention of type 2 diabetes in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: The diaphragma juglandis (DJ) comes from the wooden septum in the core of Juglans regia L, also known as the walnut septum. In Iranian traditional medicine, walnut distraction wood was widely used in the treatment of diabetes. However, there is a lack of research data on the mechanism of DJ against diabetes. AIM OF THE STUDY: To explore the protective effect of diaphragma juglandis extract (DJE) on type 2 diabetic rats and the hypoglycemic mechanism of DJE. MATERIAL AND METHODS: Supplemented DJE and fed a high-fat diet for five weeks, and then injected low-dose STZ, successfully induced type 2 diabetic rats. Collected rat serum, liver, pancreas and feces to determine the biochemical parameters of serum and liver, analyze the pathological damages of pancreas and liver, and measure the changes of gut microbes in feces. RESULTS: DJE could inhibit the metabolic abnormalities of T2DM by improving insulin resistance, abnormal lipid metabolism, liver damage, oxidative stress, and reducing inflammation. DJE significantly held fasting blood glucose, glycosylated serum protein, serum low density lipoprotein, high density lipoprotein, oral glucose tolerance test, nitric oxide, superoxide dismutase and catalase, serum and liver triglycerides, total cholesterol, aspartate aminotransferase, alanine aminotransferase, malondialdehyde, lipopolysaccharide, fasting insulin and tumor necrosis factor-α and prevented the pathological damage of pancreas and liver. The 16SrRNA gene sequencing results showed that DJE intercepted the disorders of the fecal gut microbes, mainly including Lactobacillaceae, Rikenella, Pygmaiobacter, Oscillospiraceae and Klebsiella. Spearman correlation analysis showed that the changes of gut microbes were closely relative with biochemical parameters. CONCLUSION: DJE might prevent type 2 diabetes and its complications and hold up the disorders of gut microbes.

Glycolipid metabolism and liver transcriptomic analysis of the therapeutic effects of pressed degreased walnut meal extracts on type 2 diabetes mellitus rats.

Walnut meal (WM) is rich in polyphenols which exhibit multiple therapeutic effects. The purpose of this study was to investigate the therapeutic effects of walnut meal extracts (WMP) on glycolipid metabolism and liver transcriptomics in T2DM rats. A T2DM rat model was established by using a high-fat diet combined with streptozotocin. A 5-week WMP therapy showed the effects of decreasing water intake, excretion, fasting blood glucose, fasting insulin, and insulin resistance, increasing ß-cell function and insulin sensitivity index; meanwhile regulating dysfunctional lipid metabolism and reducing inflammation; improving body weight, oral glucose tolerance test and insulin sensitivity; and increasing the activities of SOD and CAT while decreasing the MDA levels in the liver and serum of T2DM rats. Moreover, 10 key differentially expressed genes were identified by RNA-seq, including Gck, RT1-Ba, Fasn, Slc13a3, Cd74, Jun, Cyp4a1, Myh7b, Plin3, and Got1, and they were highly potentially related to glycolipid metabolism. Our results suggested that WMP exhibited the anti-diabetic effect and could regulate glycolipid metabolism in T2DM rats. This finding might assist in identifying potential therapeutic targets for T2DM prevention and intervention.