Effect of quercetin on galactose-induced hyperglycaemic oxidative stress in hepatic and neuronal tissues of Wistar rats.

In recent times there has been great demand for natural products that have possible preventive action against diabetes and its secondary complications. Keeping this in mind, this study was undertaken to investigate the influence of the flavonoid, quercetin, on oxidative stress markers and the antioxidant defence system of hepatic and neuronal tissues from galactose-induced hyperglycaemic rats. Weanling male Wistar rats were treated with 30% galactose in AIN 93 diet (group B, n=8) to induce hyperglycaemia. Control rats received normal Stock AIN 93 diet (group A, n=8). The third set of rats received group B diet with quercetin at 400 mg/100 g diet (group C, n=8). Glucose levels and body weights were measured on a weekly basis for four weeks to monitor the hyperglycaemia induced by galactose feeding. Parameters involved in the pathogenesis of galactose-induced hyperglycaemia, which included organosomatic index, protein content, antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), tryptophan fluorescence, content of protein carbonyls, prooxidant malonaldehyde (MDA) and glutathione (GSH) in hepatic and neuronal tissues were determined at the end of the fourth week. The study suggest that quercetin counters the pro-oxidant effects of galactose-induced hyperglycaemic stress, as there was a significant reversal of changes with respect to body weights, organosomatic index of hepatic and neuronal tissues, lipid peroxidation, protein carbonyl content, reduced glutathione and activities of antioxidant enzymes. In addition, treatment with quercetin appears to reduce the osmotic stress induced by hyperglycaemia, as assessed by polyol pathway enzyme aldose reductase. These results imply that inclusion of quercetin in the diet controls, to some extent, galactose-induced hyperglycaemia and its attendant complications.

Effect of arsenite on certain aspects of protein metabolism in fresh water teleost, Tilapia mossambica (Peters).

The sublethal toxicity of sodium arsenite on protein metabolism was investigated in teleost fish, Tilalpia mossambica at the end of 24, 48, 72 and 96 h of exposure. Total protein content, free amino acid content and activities of the enzymes aspartate amino transferase (AAT) and alanine amino transferase (ALAT) in liver, gill, brain and muscle exhibited significant (P<0.05) alterations throughout the investigation in relation to that of control. It is suggested that the fish is able to respond to the stressful situations by gearing up the metabolic activity as revealed by the elevated protein, amino acid content and the activities of AAT and ALAT.

Respiratory symptoms and spirometric observations in relation to atmospheric pollutants in a sample of urban population.

The prevalence of respiratory problems and the ventilatory functions in subjects belonging to three sample areas with different levels of pollution was studied to ascertain if there is any association between air pollutant levels and abnormal ventilatory functions. The predominant activity existing in that area served as the basis for stratification of the city into industrial (Group I), commercial (Group II) and residential (Group III) areas. Ambient air quality data of suspended particulate matter SPM, SO2 and NOx of the three sample areas were measured using standard methods. 216 men included in the study were administered the American Thoracic Society--Division of Lung Diseases ATS-DLD respiratory questionnaire, clinically examined and subjected to routine laboratory investigations. Spirometry and salbutamol reversibility tests were performed as per the ATS guidelines 1991. The mean and peak levels of SPM in the commercial area and the peak levels in the residential area were higher than the National Ambient Air Quality Standards (NAAQS). The mean and peak levels of NOx and SO2 in all the three areas were lower than the NAAQS. A high prevalence of approximately 30-50% of respiratory symptoms was reported in the present study. Respiratory and ventilatory abnormalities were higher in the commercial areas, which are associated with the higher mean and peak levels of SO2 and the peak levels of NOx. The pollution control measures should also aim at the peak levels of pollutants as they have been shown to exacerbate the respiratory symptoms in the present study.

Modulatory effect of sepia shell extract on activity of glucose-6-phosphatase and alanine amino transferase in diabetic mice.

Alkali extract of sepia shell possesses hypoglycemic effect. The status of glycogen and pyruvate and the activity of glucose-6-phosphatase and alanine amino transferase in liver was studied under the influence of sepia shell extract in both normal and streptozotocin induced diabetic mice. The glycogen concentration was elevated steeply in both and the pyruvate concentration increased substantially in diabetic mice, while the activity of glucose-6-phosphatase and alanine amino transferase was inhibited in normal and diabetic mice. The sepia shell extract enhances glycogenesis and reduces the formation of glucose from metabolic intermediates like pyruvate and glucose-1-phosphate and by suppressing gluconeogenesis.

Glycogenic effect of an alkali soluble fraction from sepia shell.

The alkali soluble fraction of the sepia shell possesses both anticonvulsant and hypoglycemic effect. The investigation regarding the fate of the blood sugar during the hypoglycemia revealed that the sepia shell extract acts as a glycogenic agent by mobilising the blood sugar towards liver glycogen reserve through the modulation of the enzymes glycogen phosphorylase a and ab in normal and streptozotocin diabetic mice. The glucose tolerance test (GTT) showed a depression in the GTT curve in experimental mice. The available literature on the biochemistry of the shell reveals that it contains glucosamines and some amino acid residues. The presence of amine group may resemble the sulfonylureas like tolbutamide which also possesses both anticonvulsant and hypoglycemic effect.

Accumulation of lead and effects on total lipids and lipid derivatives in the freshwater fish Anabas testudineus (Bloch).

Exposure of a freshwater fish to several sublethal concentrations (1.25, 2.50, 5.00, 10.00, and 20.00 mg/liter) of lead for a period of 30 days showed significant accumulation of lead in the blood and tissues. Lead bioaccumulated in the study showed organ-specific distribution, with high levels in the blood followed by the kidney, gill, liver, and brain and comparatively lesser amounts in the ovary and muscle tissues. The lead accumulation in tissues was found to increase with lead in water up to a concentration of 5 mg/liter, and at concentrations of 10 and 20 mg/liter the lead accumulation in the tissues, although indicating an increase, was not proportional to the concentration in water. Exposure of the freshwater fish Anabas testudineus to a sublethal (5 ppm) concentration of lead nitrate for a period of 30 days during the preparatory phase of its annual reproductive cycle reduced the total lipids, phospholipids, and cholesterol levels in the liver and ovary tissues while the free fatty acid levels were increased and lipase activity was elevated. All the parameters in the blood were found to increase. These results suggest that lead nitrate affects the lipid metabolism of the fish and this may reduce the fecundity of the fish since lipids are known to play an important role in teleost reproduction as an energy source and a precursor of steroids.

Antifeeding and insect-growth-regulating activity of certain metal complexes towards Spodoptera litura; F.

Metal complexes of divalent cobalt, nickel and copper and trivalent iron were synthesized using N-salicylidene-3-aminocoumarin as chelating agent. The ligand behaves as a monobasic ONO donor towards Co(II), Ni(II) and Cu(II) and as an ON as well as an ONO donor towards Fe(III). All the complexes have been proposed to have octahedral geometry on the basis of analytical, thermal conductivity, spectral and magnetic data. The complexes have been screened against Spodoptera litura; F (Lepidoptera: noctuiidae) for antifeeding and insect-growth-regulating activity. The results show appreciable insect-growth-regulating activity associated with metal complexation.

The disposition of carbaryl in the hepatopancreas, haemolymph and embryos of the viviparous scorpion, Heterometrus fulvipes (Koch) during gestation.

1. The disposition of carbaryl in the hepatopancreas and haemolymph of maternal animals and embryos of H. fulvipes (scorpion) after administration of a single sublethal dose was studied by g.l.c. 2. High levels of carbaryl were observed in haemolymph at 10 min, and in hepatopancreas at 1 h after administration. About 90% of the residues in the hepatopancreas were eliminated by 24 h. 3. In embryos high levels were noticed 6 h after administration and only 60% of the accumulated carbaryl was eliminated by 24 h. Carbaryl residues were observed in embryos even 1 week after administration.

Purification and characterization of bovine brain glucocerebrosidase.

Glucocerebrosidase was isolated from bovine brain by cholate extraction, ammonium sulfate fractionation, acid precipitation at pH 5.35, and hydrophobic chromatography. The purification is about 2400-fold with a specific activity of about 286,000 nmole/hr/mg protein. Molecular weight as determined by chromatography on Bio-Gel P-200 was 138,000. On SDS-polyacrylamide gel electrophoresis the enzyme protein resolved into two bands with apparent molecular weights of 63,000 and 56,000. These bands are cross-reactive to monospecific polyclonal antibody to homogeneous human placental glucocerebrosidase. The enzyme was found to be a complex glycoprotein based on its lectin binding specificity. Brain enzyme was found to be similar to placental glucocerebrosidase in its pH optima, heat stability at 52 degrees C, and substrate affinity. Enzyme kinetics were measured in the presence of conduritol-beta-epoxide, an irreversible inhibitor, and gluconolactone, a competitive inhibitor.

Inhibition of arginase in sheep brain homogenates by some L-amino acids.

The effect of 16 L-amino acids on the activity levels of arginase in sheep brain homogenates was studied. The amino acids leucine, valine, lysine, and ornithine inhibited arginase activity significantly. The other amino acids tested did not show a significant influence on arginase activity. The inhibition was related to the carbon chain length of the amino acids.