Pleurotus tuber-regium inclusion in diet ameliorates dyslipidaemia in obese-type 2 diabetic rats

Background Pleurotus tuber-regium (P.T) is an edible mushroom with abundant polysaccharides that has been used in traditional medicine to treat diabetes mellitus. This study investigated the hypoglycaemic potential and ameliorative activity of Pleurotus tuber-regium incorporated diet on diabetes induced dyslipidaemia. Materials and methods Thirty five (35) adult male wistar rats were randomly assigned to seven groups; Normal control, diabetic control, obese control, obese diabetic control, 10% PT, 20% PT, and Drug control. Type II DM was induced by placing the animals on high fat diet for a period of 10 weeks and a single intraperitoneal injection of streptozotocin (50 mg/kg/BW). P. T was incorporated into the feed and given to the animals for two weeks daily after the confirmation of diabetes. Results Treatment of the obese diabetic rats with P. T supplemented diet caused a decrease in the blood glucose level compared to the control groups. Increased organo-somatic ratio of the kidney and heart were markedly (p < 0.05) reduced following treatment (20% P.T). Furthermore, cholesterol, triglycerides, LDL-C and VLDL-C levels were reduced due to treatment accompanied by increased HDL-C in the liver. Histological evaluation of the liver, kidney, heart, and pancreas of the P. T treated groups were comparable to normal. Conclusion Incorporation of P. tuber-regium in diets could be effective in reversing dyslipidaemia in obese diabetic patients.

Characteristics of bile acid composition in high fat diet-induced nonalcoholic fatty liver disease in obese diabetic rats

Bile acid has attracted attention as a signal transmission molecule in energy metabolism. Although a high-fat diet (HFD) or obesity is known to increase hepatic fat content and alter bile acid composition, the changes in bile acid composition due to HFD or obesity remain to be elucidated. We sought to examine the bile acid composition in high fat diet-induced non-alcoholic fatty liver disease (NAFLD) in obese diabetic rats. Eight-week-old male spontaneously diabetic Torii fatty (SDTF) rats or control rats were fed an HFD. Twelve weeks post the commencement of HFD, serum and hepatic bile acid compositions and serum GLP-1 levels, which is stimulated by the secondary bile acid deoxycholic acid (DCA), were measured. The correlation between the bile acid composition and serum GLP-1 levels was also examined. While serum and hepatic levels of cholic acid (CA), a primary bile acid, tended to decrease in HFD-fed control rats, they were significantly decreased in HFD-fed SDTF rats. Hepatic CYP8B1, which plays a role in CA synthesis, the mRNA levels were significantly decreased in HFD-fed control and SDTF rats. In contrast, while serum and hepatic DCA levels were not changed in HFD-fed control rats, they were decreased in HFD-fed SDTF rats. Hepatic DCA/CA did not change in HFD-fed SDTF rats, but significantly increased in HFD-fed control rats. While serum GLP-1 levels were not changed in SDTF rats, they were significantly increased in HFD-fed control rats. Hepatic DCA/CA tended to correlate with serum GLP-1 levels, which tended to negatively correlate with the hepatic triglyceride content in SDTF rats. These results indicate that relatively increased DCA might contribute to an increase in serum GLP-1 levels, which inhibits hepatic steatosis in NAFLD.

Effects of 22 traditional anti-diabetic medicinal plants on DPP-IV enzyme activity and glucose homeostasis in high-fat fed obese diabetic rats

The present study investigated the effects of hot water extracts of 22 medicinal plants used traditionally to treat diabetes on Dipeptidyl peptidase-IV (DPP-IV) activity both in vitro and in vivo in high-fat fed (HFF) obese-diabetic rats. Fluorometric assay was employed to determine the DPP-IV activity. For in vivo studies, HFF obese-diabetic rats were fasted for 6 h and blood was sampled at different times before and after the oral administration of the glucose alone (18 mmol/kg body weight) or with either of the four most active plant extracts (250 mg/5 ml/kg, body weight) or established DPP-IV inhibitors (10 μmol/5 ml/kg). DPP-IV inhibitors: sitagliptin, vildagliptin and diprotin A, decreased enzyme activity by a maximum of 95–99% (P&lt;0.001). Among the 22 natural anti-diabetic plants tested, AnogeissusLatifolia exhibited the most significant (P&lt;0.001) inhibitory activity (96 ± 1%) with IC50 and IC25 values of 754 and 590 μg/ml. Maximum inhibitory effects of other extracts: Aegle marmelos, Mangifera indica, Chloropsis cochinchinensis, Trigonella foenum-graecum and Azadirachta indica were (44 ±7%; 38 ± 4%; 31±1%; 28±2%; 27±2%, respectively). A maximum of 45% inhibition was observed with &gt;25 μM concentrations of selected phytochemicals (rutin). A.latifolia, A. marmelos, T. foenum-graecum and M. indica extracts improved glucose tolerance, insulin release, reduced DPP-IV activity and increased circulating active GLP-1 in HFF obese-diabetic rats (P&lt;0.05–0.001). These results suggest that ingestion of selected natural anti-diabetic plants, in particular A. latifolia, A. marmelos, T. foenum-graecum and M. indica can substantially inhibit DPP-IV and improve glucose homeostasis, thereby providing a useful therapeutic approach for the treatment of T2DM.

meliorative effects of Pergamum harmala seed extract on obese diabetic rats

Objective: To explore the potential antidiabetic activity of methanolic extract of Harmal seeds in obese-diabetic rats. Design: Randomized controlled experimental study. Animals: Forty male Sprague Dawley rats. Procedures: The P. harmala seeds methanolic extract was prepared and orally administered at two doses of 150 and 250 mg/kg to two groups of streptozotocin-induced diabetic rats. Two additional control groups were used as healthy control and obese-diabetic control groups. Animals were euthanized after 8 weeks of experimental period, blood and tissue samples were collected. Liver tissue samples were used to determine antioxidant and oxidative stress markers; while those from adipose tissue were used for estimation of PPAR gamma expression. Results: Supplementation of P. harmala methanolic extract with both doses (150 and 250 mg/kg) to diabetic rats (G3 and G4) significantly reversed the observed alterations in the levels of blood glucose, cholesterol, triglyceride, LDL, malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase (SOD) (P <0.05). . In addition, the downregulation of PPAR gamma expression in diabetic rats (G2) was also restored in rats (G3 and G4) supplemented with P.harmala methanolic extract. Conclusion and clinical relevance: Our finding revealed that Harmal seed extract has a potent antidiabetic activity in streptozotocin-induced diabetic rats that can be used as a dietary supplement by diabetic patients.