A novel Gymnema sylvestre extract stimulates insulin secretion from human islets in vivo and in vitro.

Many plant-based products have been suggested as potential antidiabetic agents, but few have been shown to be effective in treating the symptoms of Type 2 diabetes mellitus (T2DM) in human studies, and little is known of their mechanisms of action. Extracts of Gymnema sylvestre (GS) have been used for the treatment of T2DM in India for centuries. The effects of a novel high molecular weight GS extract, Om Santal Adivasi, (OSA(R)) on plasma insulin, C-peptide and glucose in a small cohort of patients with T2DM are reported here. Oral administration of OSA(R) (1 g/day, 60 days) induced significant increases in circulating insulin and C-peptide, which were associated with significant reductions in fasting and post-prandial blood glucose. In vitro measurements using isolated human islets of Langerhans demonstrated direct stimulatory effects of OSA(R) on insulin secretion from human ß-cells, consistent with an in vivo mode of action through enhancing insulin secretion. These in vivo and in vitro observations suggest that OSA(R) may provide a potential alternative therapy for the hyperglycemia associated with T2DM.

Role of clinical biochemistry laboratory in the diagnosis of diabetes mellitus.

Clinical biochemistry and laboratory help is needed at all stages of diagnosis of diabetes. Laboratory plays a key role in the management of diabetes and its complications like renal, metabolic, and others. Monitoring of treatment is also guided by regular blood sugar estimation and self-monitoring of blood glucose level.

Biochemical composition, lethality and pathophysiology of venom from two cobras-- Naja naja and N. kaouthia.

The cobras Naja naja and N. kaouthia are abundant in eastern and north-eastern India, accounting for maximum snakebite deaths. Here we report on variation in the composition of Naja kaouthia and N. naja venom from eastern India on corresponding differences in the severity of pathogenesis. These two venoms differ in chromatographic elution profile through Sephadex G-50 and enzyme activity, protein and carbohydrate contents associated with each fraction. The presence of greater amounts of basic phospholipase A2, L-amino acid oxidase and low molecular weight membrane active polypeptides in the N. naja venom makes it more toxic than N. kaouthia venom. A commercial polyvalent antivenom raised against N. naja venom inactivates lethality and variety of toxic effects of homologous venom more effectively than N. kaouthia venom.

Some biochemical properties of Russell's viper (Daboia russelli) venom from Eastern India: correlation with clinico-pathological manifestation in Russell's viper bite.

In the present study, some biochemical properties and pathological effects of Daboia russelli venom from Burdwan district of West Bengal, eastern India are presented. The clinical features of Russell's viper envenomation observed in patients admitted to Burdwan Medical College & Hospital are also reported. In vitro, whole venom exerts strong trypsin inhibitory, phospholipase A2 and procoagulant activities in addition to moderate adenosine monophosphatase and adenosine triphosphatase activities. Lethality (LD50) of this venom sample is 0.7 mg kg (i.v.) of mice. Significant local tissue damaging effects including edema, hemorrhage and necrosis are observed in experimental animal models. An increase in the level of serum enzymes, such as aspartate transaminase, alkaline phosphatase, creatine phosphokinase, lactate dehydrogenase after D. russelli venom injection in albino rats is indicative of cell or tissue damage. High incidence of intravascular hemolysis in addition to hemostasis, haemoptysis and haematuria are observed as the most prominent features of RVV envenomation from this part of India. The present study reinforces the hypothesis that variation in the venom composition of RVV from eastern India with respect to venom samples of Russell's vipers from other parts of India is responsible for the differences in the clinical manifestation in patients from eastern India.

The composition of Naja naja venom samples from three districts of West Bengal, India.

The variation in the composition of Naja naja venoms from three neighbouring districts of West Bengal, eastern India and the corresponding differences in the severity of pathogenesis due to venom composition variation are reported. These venom samples differ with respect to chromatographic elution profile and enzyme activity associated with each fraction. Presence of higher quantities of basic phospholipase and plasma protein hydrolase in the venom samples of Burdwan and Purulia make them more toxic than Midnapur venom sample. A polyvalent antivenom manufactured in western India was hardly effective in neutralizing the pathobiological manifestation of the venom samples from eastern India.

Lysosomal membrane stabilization by alpha-tocopherol against the damaging action of Vipera russelli venom phospholipase A2.

This investigation shows the membrane stabilizing effect of alpha-tocopherol against the damaging action of viper venom phospholipase A2 (PLA2). Liver lysosomal membranes from rats fed 100 mg and 200 mg alpha-tocopherol acetate per kilogram of diet were more resistant to damage by viper venom PLA2 compared with vitamin E-deficient rats. The membrane stabilizing effect of vitamin E is proposed to be due to the formation of a complex with the phospholipid hydrolysis products of the membrane.

Effect of dietary supplementation of vitamin E in partial inhibition of Russell's viper venom phospholipase A2 induced hepatocellular and microsomal membrane damage in rats.

The current investigation furnishes a good correlation between the alpha-tocopherol content of the liver and microsomes and corresponding inhibition of Russell's viper venom phospholipase A2 inflicted damage to them. Dietary supplementation of d1-alpha-tocopherol at a concentration of 100 mg and 200 mg per kg of diet displayed less damage caused by venom phospholipase A2 in sharp contrast to the vitamin E deficient rats. alpha-tocopherol due presumably to the formation of complexes with the phospholipid hydrolysis products of the membranes, plays a significant role in membrane stabilization.

Frusemide-induced diabetes mellitus in insulin pretreated rabbits as an experimental model.

Single dose of frusemide 0.1 mg/kg orally was administered in 10 rabbits pretreated with soluble insulin 4 IU intravenously. Induction of diabetes after 24 h was confirmed by an increase in blood sugar and glucosylated haemoglobin and a decrease in serum insulin levels. Ten diabetic rabbits which received only frusemide without insulin pretreatment were used as controls, whereas equal number of insulin-pretreated rabbits receiving hydrochlorothiazide 250 mg/kg orally served as the positive control group. All biochemical parameters remained unaltered in the frusemide-treated test group as well as the positive control group after two weeks. The pancreatotoxic effect of frusemide may induce a stable hyperglycaemic state in rabbits which could lead to a useful diabetic model.

Epidemiology of Japanese encephalitis.

Seven hundred and sixty-two cases of Japanese Encephalitis (JE) were studied during the last 5 years (1985-1989) in relation to age, sex, religion, nutritional status, living habits, exposure to domestic animals and mosquitos, clinical profile, seasonal variation and mortality pattern. The maximum occurrence was in 1987-1988 and it showed a preponderance in males (51-82%). The disease is progressively decreasing in Muslims (3-7%) and gradually increasing in tribes (25-60%). Children in the age-group of 6-7 years (19-25%) were maximally affected and the disease was rare in infancy. The common features were coma, convulsions, neck rigidity and fever (88-97%). Gastrointestinal manifestations were rare (3.6%) but were associated with the highest mortality. About 80-95% had exposure to domestic animals directly or indirectly and 95% of the patients were not using mosquito nets. The CSF protein and sugar content were normal, with or without slight leucocytosis while the lymphocyte count was variable. The CSF and blood picture had no significant relation with clinical presentation and prognosis.

In vivo chloroquine resistant P. falciparum in Calcutta. A case report.

An in vivo chloroquine resistant P. falciparum malaria case is reported from Calcutta. The resistance level being R-1. The patient responded well to pyrimethamine and sulfadoxine combination, which appears to be the drug of choice in Calcutta for choloroquine resistant P. falciparum malaria as quinine is not available.

Biochemical studies of liver & liver microsomes in envenomated rats.

Some biochemical parameters of liver and liver microsomes were studied in albino rats following administration of cobra and viper venoms at dose of 2 mg/kg body weight. The total protein content in cobra venom treated (CVT) animals and DNA and RNA contents of liver and liver microsomes were almost unaltered in both the venom treated animals while total protein content was significantly reduced in viper venom treated (VVT) animals. Alkaline and acid phosphatases activities of whole liver showed significant increase in both the venom treated animals whereas the rise in cholinesterase activity in CVT animals was not significant. Lactic acid content was significantly higher in CVT animals compared to either VVT animals or controls. The glycolytic enzymes viz., aldolase, phosphohexose isomerase and lactate dehydrogenase measured in hepatic microsomal fraction were significantly reduced while alanine and aspartate aminotransferases and gamma-glutamyl transpeptidase activities of liver microsomes were significantly elevated in both the venom treated animals compared to controls.

Changes in lipid profiles of brain of albino rats following envenomation.

Effect of high doses of cobra venom (150 micrograms/120 +/- 20 g body weight) and viper venom (300 micrograms/120 +/- 20 g body weight) on total lipid, triglyceride, phospholipid, cholesterol, high density lipoprotein cholesterol (HDL-C) and low density lipoprotein cholesterol (LDL-C) of brain of albino rats was studied. Total lipid (TL) triglyceride (TG) and phospholipid (PL) are decreased in both viper and cobra venom treated groups while cholesterol (C), and LDL-C are increased in both the groups in relation to controlled ones. HDL-C content was almost unaltered. Decrease in triglyceride and phospholipid may be due to effect of lipases and phospholipases whereas increased cholesterol and LDL-C may be attributed to lysis of cell membrane.

Biochemical evidence for mediatory role of 5-hydroxytryptamine in the uterotonic action of prostaglandin F2oc.

5-Hydroxytryptamine (5-HT) is reported to be involved in endogenous prostaglandin (PG)--modulated as well as exogenous PG-induced pharmacological activities including oxytocic effect of PGE1 PGE2oc Biochemical parameters were undertaken for further studies into the possible role of 5-HT in the uterotonic effect of PGF2oc on isolated oestronised rat uterus. The results substantiate the involvement of endogenous 5-HT in the uterotonic effect of PGF2oc.

Mechanism and pathway of glucose transportation in a digenetic trematode Ceylonocotyle scoliocoelium.

The mode of absorption, kinetics and mechanism of transportation of 14C--glucose in a digenetic trematode, Ceylonocotyle scoliocoelium were studied by culturing the trematodes under in vitro condition in Hank's saline supplemented with radioactive tracer. It was then followed separately by autoradiography and liquid scintillation. Autoradiographic study reveals that the maximum amount of glucose uptake occurs through cuticle whereas the role of intestinal canal is insignificant in this respect. Maximum cpm is recorded in the precipitate followed by TCA treatment. This is due to the presence of a protein-bound 14C-glucose which is assumed as the carrier protein. The inhibitor, phlorizin, used here presumably acts noncompetitively.

Effect of envenomation on enzymes of brain of albino rats.

Effects of high doses of cobra venom, (150 micrograms/120 +/- 20 g body wt) and viper venom (300 micrograms/120 +/- 20 g body wt) on aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), acetylcholinesterase (ACh) and alkaline phosphatase (ALP) of brain of albino rats were studied. While AST, LDH, ACh and ALP activities increased in both viper and cobra venom treated rats, ALT decreased in both groups compared to control.