Comparative effects of mature coconut water (Cocos nucifera) and glibenclamide on some biochemical parameters in alloxan induced diabetic rats

In the present study, comparative effects of mature coconut water (Cocos nucifera L., Arecaceae) and glibenclamide in alloxan induced diabetic rats were evaluated. Diabetes mellitus was induced in Sprague-Dawly rats using alloxan monohydrate (150 mg kg-1 body weight). Treatment with lyophilized form of mature coconut water and glibenclamide in diabetic rats reduced the blood glucose and glycated hemoglobin along with improvement in plasma insulin level. Elevated levels of liver function enzymes markers like alkaline phosphatase, serum glutamate oxaloacetate transaminase and serum glutamate pyruvate transaminase in diabetic rats were significantly reduced on treatment with mature coconut water. In addition to this, diabetic rats showed altered levels of blood urea, serum creatinine, albumin, albumin/globulin ratio which were significantly improved by treatment with mature coconut water and glibenclamide. Activities of nitric oxide synthase in liver and plasma L-arginine were reduced significantly in alloxan induced diabetic rats while treatment with mature coconut water reversed these changes. The overall results show that mature coconut water has significant beneficial effects in diabetic rats and its effects were comparable to that of glibenclamide, a well known antidiabetic drug.

Virgin coconut oil improves hepatic lipid metabolism in rats–compared with copra oil, olive oil and sunflower oil.

Effect of virgin coconut oil (VCO) on lipid levels and regulation of lipid metabolism compared with copra oil (CO), olive oil (OO), and sunflower oil (SFO) has been reported. Male Sprague-Dawley rats were fed different oils at 8% level for 45 days along with synthetic diet. Results showed that VCO feeding significantly lowered (P<0.05) levels of total cholesterol, LDL+ VLDL cholesterol, Apo B and triglycerides in serum and tissues compared to rats fed CO, OO and SFO, while HDL-cholesterol and Apo A1 were significantly (P<0.05) higher in serum of rats fed VCO than other groups. Hepatic lipogenesis was also down regulated in VCO fed rats, which was evident from the decreased activities of enzymes viz., HMG CoA reductase, glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase and malic enzyme. In addition, VCO significantly (P<0.05) increased the activities of lipoprotein lipase, lecithin cholesterol acyl transferase and enhanced formation of bile acids. Results demonstrated hypolipidemic effect of VCO by regulating the synthesis and degradation of lipids.

Influence of coconut kernel protein on lipid metabolism in alcohol fed rats.

Male albino rats were given ethanol (3.76 g/kg body weight/day) to induce hyperlipidemia. The rats showed increased concentration of cholesterol and triglycerides in the serum and tissues. Inclusion of coconut protein and L-arginine into ethanol fed rats produced lower levels of total cholesterol, LDL+ VLDL cholesterol, triglycerides and atherogenic index in the serum. Concentration of tissue cholesterol and triglycerides was also lower in these groups. Administration of coconut protein and L-arginine in the ethanol fed rats caused decreased activity of HMG-CoA reductase in the liver and increased activity of lipoprotein lipase in the heart. The activities of malic enzyme and glucose-6-phosphate dehydrogenase were also lower in these groups. Feeding coconut protein and L-arginine in ethanol treated rats showed increased concentration of hepatic bile acids and fecal excretion of neutral sterols and bile acids. All these effects were comparable in rats fed coconut protein and those fed L-arginine. These observations indicate that the major factor responsible for the hypolipidemic effect of coconut protein is due to the high content of L-arginine.

Hypolipidemic and antiperoxidative effect of coconut protein in hypercholesterolemic rats.

Effect of coconut protein in rats fed high fat cholesterol containing diet on the metabolism of lipids and lipid peroxides was studied. In addition, effect of coconut protein were compared with rats fed L-arginine. The results indicate that those fed coconut protein and those fed L-arginine showed significantly lower levels of total cholesterol, LDL+ VLDL cholesterol, Triglycerides and Phospholipids in the serum and higher levels of serum HDL cholesterol. The concentration of total cholesterol, triglycerides and phospholipids in the tissues were lower in these groups. There was increased hepatic cholesterogenesis which is evident from the higher rate of incorporation of labeled acetate into free cholesterol. Increased conversion of cholesterol to bile acids and increased fecal excretion of bile acids were observed. Feeding coconut protein results in decreased levels of Malondialdehyde in the heart and increased activity of Superoxide dismutase and Catalase. Supplementation of coconut protein causes increased excretion of urinary nitrate which implies higher rate of conversion of arginine into nitric oxide. In the present study, the arginine supplemented group and the coconut protein fed group produced similar effects. These studies clearly demonstrate that coconut protein is able to reduce hyperlipidemia and peroxidative effect induced by high fat cholesterol containing diet and these effects are mainly mediated by the L-arginine present in it.

Effects of different levels of coconut fiber on blood glucose, serum insulin and minerals in rats.

The effect of neutral detergent fiber (NDF) from coconut kernel (Cocos nucifera L) in rats fed 5%, 15% and 30% level on the concentration of blood glucose, serum insulin and excretion of minerals was studied. Increase in the intake of fiber resulted in significant decrease in the level of blood glucose and serum insulin. Faecal excretion of Cu, Cr, Mn, Mg, Zn and Ca was found to increase in rats fed different levels of coconut fiber when compared to fiber free group. The result of the present investigation suggest that inclusion of coconut fiber in the diet results in significant hypoglycemic action.

Biochemical effects of garlic protein on lipid metabolism in alcohol fed rats.

Garlic protein is a very good hypolipidemic agent. In the present study the water soluble protein fraction of garlic was investigated for its effect on hyperlipidemia induced by alcohol (3.76 g/kg. body wt./day). The hypolipidemic action is mainly due to an increase in cholesterol degradation to bile acids and neutral sterols and mobilization of triacyl glycerols in treated rats. Garlic protein (500 mg./kg body wt./day) showed significant hypolipidemic action comparable with a standard dose of gugu-lipid (50 mg./kg. body wt./day).

Hypolipidemic effect of hemicellulose component of coconut fiber.

The neutral detergent fiber (NDF) isolated from coconut kernel was digested with cellulase and hemicellulase and the residual fiber rich in hemicellulose (without cellulose) and cellulose (with out hemicellulose) were fed to rats and compared with a fiber free group. The results indicate that hemicellulose rich fiber showed decreased concentration of total cholesterol, LDL + VLDL cholesterol and increased HDL cholesterol, while cellulose rich fiber showed no significant alteration. There was increased HMG CoA reductase activity and increased incorporation of labeled acetate into free cholesterol. Rats fed hemicellulose rich coconut fiber produced lower concentration of triglycerides and phospholipids and lower release of lipoproteins into circulation. There was increased concentration of hepatic bile acids and increased excretion of faecal sterols and bile acids. These results indicate that the hemicellulose component of coconut fiber was responsible for the observed hypolipidemic effect.

Antiperoxide effect of garlic protein in alcohol fed rats.

Rats fed ethanol (3.76g/Kg body wt/day) for about 45 days exhibited high levels of tissue malondialdehyde, hydroperoxide and diene conjugates. Activity of tissue superoxide dismutase, catalase, and glutathione content decreased. Administration of water soluble proteins of garlic (500 mg/kg body wt/day) to alcohol fed rats showed significant increase in antiperoxide activity and decrease in the activity of glutathione peroxidase and glutathione s transferase as compared to a standard drug gugulipid (50 mg/kg body wt/day).

Lysine: arginine ratio of a protein influences cholesterol metabolism. Part 1--Studies on sesame protein having low lysine: arginine ratio.

The effect of globulin fraction with a lysine: arginine (lys:arg) ratio 0.67, isolated from sesame (Sesamum Indicum) seeds on cholesterol metabolism was studied in rats fed cholesterol free and cholesterol containing diet and compared with casein (lys:arg ratio-2.0). Rats fed sesame seed globulin showed significantly lower concentrations of cholesterol in the serum and aorta. The decrease in serum was manifested in both HDL and LDL + VLDL fractions. There was increased cholesterogenesis in the liver as was evident from increased incorporation of labeled acetate into cholesterol and increased activity of 3-Hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase. Increased hepatic diversion of cholesterol to bile acid synthesis and increased fecal excretion of bile acids and sterols were also observed in rats fed sesame seed globulins. Rats fed sesame globulins also showed significantly higher activity of lipoprotein lipase in the heart and adipose tissue and that of plasma Lecithin: cholesterol acyltransferase (LCAT). These studies suggest that low lysine: arginine ratios of a protein exert hypocholesterolemic effects.

Antiatherogenic effect of a low lysine: arginine ratio of protein involves alteration in the aortic glycosamihoglycans and glycoproteins.

The effect of alteration of lysine: arginine ratio of the protein on the aortic glycosaminoglycans and glycoproteins was studied in rats fed cholesterol free and atherogenic diet. The concentration of total glycosaminoglycans and of individual fractions was significantly lower in the aorta in the case of diet with lysine: arginine ratio of 1·0, than the diet with a ratio of 2·0. Rats fed globulin fraction isolated from sesame seeds, which has a lysine: arginine ratio of 0·67 also showed significantly lower concentration of total and individual glycosaminoglycan fractions in the aorta than those fed casein (lysine:arginine ratio 2·0). Concentration of total hexose and fucose in the glycoproteins was also lower in the aorta in the case of lysine: arginine ratio 1·0. These results in the light of previous reports of increase in the aortic glycosaminoglycans in the early stages of atherosclerosis and increase in the total hexose and fucose in the glycoproteins in the atherosclerotic aorta indicate that the antiatherogenic effect of a low lysine: arginine ratio in the protein involves alteration in the aortic glycosaminoglycans and glycoproteins.