Coriandrum sativum changes the levels of lipid peroxides and activity of antioxidant enzymes in experimental animals.

The antiperoxidative effect of coriander seeds (Coriandrum sativum) was studied in rats administered high fat diet. Significant decrease in the levels of lipid peroxides, free fatty acids and glutathione was observed when compared to control group whereas the activity of antioxidant enzymes showed increase.

Identification and estimation of endogenous digoxin in biological fluids and tissues by TLC and HPLC.

A procedure for estimation of digoxin in biological samples after adding a known quantity of digoxin followed by extraction, separation by TLC and HPLC is described. The identity of digoxin thus extracted from rat brain has been established by reaction with digoxin antibody and by its inhibition of Na(+)-K+ ATPase activity. The method could be a better substitute to the routine radioimmunoassay as interfering substances are removed by TLC and HPLC.

Endogenous alkaloids in the brain of rats loaded with tyrosine/tryptophan & in the serum of patients of neurodegenerative & psychiatric disorders.

Since binding sites for morphine, nicotine and strychnine exist in the brain, it is possible that they may have some role in neuronal function. The presence/variation in the levels of these alkaloids in the brain of rats fed tryptophan and tyrosine, and in the serum of patients with some neurodegenerative and psychiatric disorders were studied. Brain of rats loaded with tyrosine (500 mg/kg b wt X 14 days) showed increased amounts of morphine, while that from animals loaded with tryptophan (in the same dose) showed presence of strychnine and increased amounts of nicotine. Strychnine is being reported in mammalian brain for the first time. Serum of patients with epilepsy, Parkinson's disease (PD) and manic depressive psychosis (MDP) was also examined for the presence of these alkaloids. Serum of control subjects did not show the presence of any of these alkaloids, while that of all 3 patients groups contained strychnine. Morphine was present only in the serum of patients of MDP. Nicotine was present in trace amounts in the serum of all these patients. Presence of these alkaloids in the serum of patients of neurodegenerative and psychiatric disorders is being reported for the first time, to the best of our knowledge.

Hyperglycemic effect of low protein cassava diet.

Hyperglycemic effect of cassava diet in presence of varying amounts of protein has been carried out. The rats fed a low protein high cyanide diet showed an increase in the blood glucose and a decrease in the liver glycogen. The activity of glycogen phosphorylase, glucose 6-phosphatase and phosphoglucomutase showed higher levels in the liver of low protein high cyanide group compared to the control group. Also, the activity of hexokinase, and isocitrate dehydrogenase activity in the liver of high cyanide low protein were significantly low. The results suggests that cassava diet with the low protein can induce hyperglycemia.

Anti-oxidant effects of curry leaf, Murraya koenigii and mustard seeds, Brassica juncea in rats fed with high fat diet.

Status of lipid peroxidation was studied in rats induced high fat diet and some commonly used spices, viz. Murraya koenigit and Brassica juncea. The study revealed that these species alter the peroxidation (thiobarbituric acid reactive substances) level to a beneficial extent. Histological studies also focus on modulation of hepatic functions to near normal level.

Role of Murraya koenigii (curry leaf) and Brassica juncea (Mustard) in lipid peroxidation.

The status of lipid peroxidation was investigated in rats fed M. Koenigii (curry leaf) and B. juncea (Mustard). Concentration of malondialdehyde showed a significant decrease, while hydroperoxides and conjugated dienes were significantly increased in liver and heart of both the experimental groups. SOD and catalase activity was found to be increased in liver and heart of both the spices administered groups. Glutathione levels in liver, heart and kidney were lowered in rats administered these spices. Glutathione reductase, glutathione peroxidase and glutathione S-transferase activity showed a sharp increase in the experimental groups compared to the controls.

Effect of protein supplemented cassava diet in rats.

The effect of feeding rats with cassava diet (tapioca) has been investigated with respect to the activities of superoxide dismutase, catalase and levels of TBARS. By varying the levels of protein in the diet and cyanide content of cassava, the possible role of a high protein diet in the prevention of oxidant stress has been shown. Rhodanese which detoxifes cyanide is also found to be inhibited in rats fed low protein diet while the inhibition was only marginal in the high protein fed groups.

Influence of components of oral contraceptive on lipid metabolism.

Oral contraceptives (OC) have been shown to enhance the risk of atherosclerosis. In the present study we sought to determine which component of the OC (containing 0.067 mg estrogen and 0.667 mg of progestin) counts for alteration in lipids profile. Female rats were administered with 0.067 mg of 17 beta-estradiol and 0.667 mg of norethindron acetate/kg body weight. Estrogen treatment exhibited higher levels of lipids in the serum and tissues. LDL-cholesterol increased by three folds but HDL-cholesterol decreased significantly, while progestin group showed decreased levels of lipids and LDL cholesterol. Elevated hepatic cholesterogenesis was observed as indicated by increased activity of HMG-CoA reductase and elevated incorporation of labelled acetate into liver cholesterol in estrogen group. On the other hand, progestin treatment did not alter the activity of HMG-CoA reductase and the rate of incorporation of labelled acetate into hepatic cholesterol. Hepatic degradation of cholesterol to bile acids however, decreased with estrogen treatment. No considerable changes were observed in hepatic bile acid levels in progestin group. Release of lipoprotein into circulation increased but their clearance from the circulation decreased as revealed by the activity of lipoprotein lipase (LPL) of extrahepatic tissues in estrogen group. With progestin treatment, activity of LPL increased significantly in adipose tissue. Activity of hepatic malic enzyme and glucose 6-phosphate dehydrogenase enhanced considerably in estrogen group, while activities of these enzymes were depressed with progestin administration. Thus results indicate that estrogen component of oral pills counts for major changes in lipid and lipoprotein metabolism favouring the development of atherosclerosis.

Haematological & histological studies after curry leaf (Murraya koenigii) & mustard (Brassica juncea) feeding in rats.

Whole curry leaf and mustard fed to rats at doses equal to normal human intake did not cause any adverse effect on food efficiency ratio (FER), red blood cell count (RBC), white blood cells (WBC), total count, differential counts or on the levels of blood constituents, like serum electrolytes, blood urea, haemoglobin, total serum protein, albumin-globulin ratio, fibrin level, glycosylated haemoglobin and the activity of glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) and alkaline phosphatase in serum. No histopathological changes were observed in the liver of rats administered curry leaf and mustard.

Hypoglycemic action of Murraya koenigii (curry leaf) and Brassica juncea (mustard): mechanism of action.

Effect of Murraya koenigii and Brassica juncea on carbohydrate metabolism has been studied using rats as experimental animals. Both showed significant hypoglycemic action. There was increase in the concentration of hepatic glycogen and glycogenesis, as evident from the increased activity of glycogen synthetase, and decrease in glycogenolysis and gluconeogenesis as evident from the decreased activity of glycogen phosphorylase and gluconeogenic enzymes.

Elevated serum glycosaminoglycans with hypomagnesemia in patients with coronary artery disease & thrombotic stroke.

Elevated levels of serum glycosaminoglycans (GAG), associated with hypomagnesemia were observed in patients of proven CAD and thrombotic stroke in Kerala. Serum lipid profile was normal in the majority of these patients, indicating that elevated serum GAG may be an even more reliable indicator of atherosclerosis than elevated serum total cholesterol or LDL cholesterol. Autopsy samples of carotid artery and aorta which had atheroma showed significantly higher GAG when compared to samples which showed no atheroma. Serum Mg levels were significantly lower in CAD and thrombotic stroke patients as compared to controls. Mg deficiency may be one of the factors involved in the increased level of GAG.

Long term administration of testosterone on ascorbic acid metabolism in castrated rats.

Orchidectomy caused a significant decrease in the concentration of ascorbic acid and ascorbic acid-2-sulphate in tissues while administration of testosterone to these animals reverses this effect. Concentration of ascorbic acid in liver in experimental groups correlates with the activity of L-qualano-lactone oxidase and dehydroascorbatase in this tissue.

Role of oral contraceptive in atherosclerosis.

The possibility that risk of a atherosclerosis complication increases with oral contraceptive use was examined by studying the effect of oral pill containing 0.067 mg menstranol and 0.667 mg ehtynodiol diacetate/kg body weight on the metabolism of lipids in female rats fed a hypercholesterolemic diet for three months. Experimental group clearly exhibited higher levels of triglycerides and cholesterol in plasma and tissues, increase in aorta observed to be two folds. Increased hepatic cholesterogenesis was noted with treatment of oral contraceptive as indicated by higher activity of HMG-CoA reductase. Activity of lipoprotein lipase of extrahepatic tissue was depressed in experimental group. Activity of plasma LCAT, an enzyme involved in the transport of cholesterol from tissues, was also lower with treatment of oral contraceptive. However, activity of malic enzyme and glucose-6-phosphate dehydrogenase enhanced considerably with administration of oral pill. The increase in plasma and aortic cholesterol levels, increase in LDL+VLDL cholesterol and considerable decrease in HDL cholesterol in animals treated with oral contraceptives and fed with atherogenic diet, indicates that prolonged administration of oral pill may predispose towards atherosclerosis.

Lipid peroxide metabolism in oophorectomised rats.

The effect of bilateral oophorectomy and the administration of beta-estradiol on lipid peroxide metabolism were studied in rats. The lipid peroxide levels were measured in the oophorectomised and the estradiol administered animals. The level of lipid peroxide increased in the liver in oophorectomised animals, whereas no change was observed in the heart. The activity of antiperoxidative enzymes superoxide dismutase and catalase was found to be decreased in both the liver and the heart. Oophorectomy resulted in the elevation of serum ceruloplasmin. Administration of estradiol to oophorectomised rats restored the altered lipid peroxide levels.

Testosterone and lipid peroxide metabolism in orchidectomised rats.

The effect of testosterone on lipid peroxides and antiperoxidative enzymes in normal and orchidectomised animals has been studied. Orchidectomy results in increased lipid peroxidation in the heart, while administration of testosterone to the animals reverses this to a certain extent. On the other hand the administration of testosterone to normal rats results in increased lipid peroxidation in the liver and heart.

Role of antibiotics in lipid peroxidation.

Alterations in the levels of lipid peroxides, superoxide dismutase, catalase, glutathione, free fatty acid and serum ceruloplasmin were studied in rats fed with high fat cholesterol diet administered different antibiotics, viz. ampicillin, tetracycline, streptomycin, chloramphenicol and cephalosporin. The concentrations of lipid peroxides, glutathione, free fatty acid decreased in most of the tissues, except in tetracycline, streptomycin and cephalosporin treated rats. The changes observed in the activities of superoxide dismutase and catalase in the liver and kidney of these antibiotics administered groups also are in accordance with the changes in lipid peroxides. The results show that the tetracycline is hepatotoxic and nephrotoxic, while cephalosporin and streptomycin are nephrotoxic.

Antibiotics & glycosaminoglycan metabolism in rats.

The administration of antibiotics to rats resulted in significant alteration in the metabolism of glycosaminoglycans (GAG). The concentrations of the total GAG and most of the fractions increased in the aorta and liver in rats given tetracycline and cephalosporin, but decreased in ampicillin and streptomycin treated groups. The activity of biosynthetic enzymes of GAG in the liver increased significantly with all the antibiotics administered, except streptomycin. The pattern of change in the activity of many of the degrading enzymes of GAG in the liver and aorta was not uniform in different antibiotics administered groups. The changes observed in the activities of biosynthetic and degrading enzymes of GAG in the liver and aorta in different antibiotics administered groups may account for the alterations in the level of GAG observed in different experimental groups.

Dietary fiber and lipid peroxidation: effect of dietary fiber on levels of lipids and lipid peroxides in high fat diet.

Effect of feeding coconut and blackgram fiber isolated as neutral detergent fiber (NDF) on the levels of lipids and lipid peroxides was studied in rats given a high fat diet. Concentration of cholesterol, free falty acid and phospholipids showed significant decrease in the serum, liver aorta and intestine of coconut and blackgram fiber groups. Concentration of malondialdehyde (MDA) and conjugated dienes was significantly decreased in liver and intestine of both fiber groups, while hydroperoxides showed significant increase in liver and heart of both the fiber groups. SOD and catalase activity was found to be increased in liver, intestine, heart proximal colon and distal colon of both the fiber groups. Serum ceruloplasmin levels showed a slight increase in animals fed coconut and blackgram fiber groups. Glutathione levels in liver, intestine proximal colon, distal colon and heart also showed a significant decrease in the animals of both the fiber groups.

Mechanism of hyperlipidemia produced by estrogen-progestin formulation.

Rats administered estrogen-progestin formulation (0.667 mg of synthetic progestin and 0.067 mg of synthetic estrogen/kg body wt) showed increased hepatic cholesterogenesis, as evidenced by an increased activity of HMG-CoA reductase and increased incorporation of labelled acetate into liver cholesterol. Hepatic degradation of cholesterol to bile acids, however, was decreased. There was increased release of lipoproteins into the circulation but their clearance from the circulation was lower as revealed by a decreased activity of lipoprotein lipase of the extrahepatic tissues. Activity of plasma LCAT, which is involved in the transport of cholesterol from the tissues, was also decreased. The increase in serum and aortic cholesterol levels, increase in LDL cholesterol and decrease in HDL cholesterol in rats administered estrogen-progestin formulation suggest that prolonged administration of this formulation may predispose towards atherosclerosis.

Similar effects of β-alanine and taurine in cholesterol metabolism.

ß-Alanine, though producing a deficiency of taurine in the tissues, had a similar effect on cholesterol metabolism as taurine. Both caused increased activity of hepatic hydroxymethylglutaryl coenzyme A reductase and increased incorporation of 1, 2 of [14C]- acetate into liver cholesterol. Both caused increased concentration of biliary cholesterol and bile acids. There was increased activity of lipoprotein lipase in heart, but decreased activity in the adipose tissue in both cases. Release of lipoproteins into circulation was decreased in both cases.