Adaptogenic activity of a novel, withanolide-free aqueous fraction from the roots of Withania somnifera Dun.

The practitioners of the traditional Indian system of medicine regard Withania somnifera Dun. as the 'Indian ginseng'. A new withanolide-free aqueous fraction was isolated from the roots of this plant and was evaluated for putative antistress activity against a battery of tests such as hypoxia time, antifatigue effect, swimming performance time, swimming induced gastric ulceration and hypothermia, immobilization induced gastric ulceration, autoanalgesia and biochemical changes in the adrenal glands. This bioactive fraction exhibited significant antistress activity in a dose-related manner in all the parameters studied. The extract of Withania somnifera root (a commercial preparation available locally) was used to compare the results. A preliminary acute toxicity study in mice showed a good margin of safety.

In vivo hepatoprotective activity of active fraction from ethanolic extract of Eclipta alba leaves.

The alcoholic extract of fresh leaves of the plant Eclipta alba (Ea), previously reported for is hepatoprotective activity was fractionated into three parts to chemically identify the most potent bioactive fraction. The hepatoprotective potential of the fraction prepared from extract was studied in vivo in rats and mice against carbon tetrachloride induced hepatotoxicity. The hepatoprotective activity was determined on the basis of their effects on parameters like hexobarbitone sleep time, zoxazolamine paralysis time, bromosulphaline clearance, serum transaminases and serum bilirubin. Fraction EaII (10-80 mg/kg, p.o.) containing coumestan wedelolactone and desmethylwedelolactone as major components with apigenin, luteolin, 4-hydroxybenzoic acid and protocateuic acid as minor constituents exhibited maximum hepatoprotective activity and is the active fraction for hepatoprotective activity of Eclipta alba leave. The acute toxicity studies have shown that like Ea, Fraction EaII also high safety margin.

Effect of amiloride on suprathreshold NaCl, LiCl, and KCl salt taste in humans.

The purpose of this study was to investigate normal variances in the response magnitudes of suprathreshold concentrations of NaCl, LiCl, and KCl salts and amiloride on the anterior human tongue. Random equimolar concentrations of salt solutions were delivered to spatially matched flow chambers of 20 volunteers at 3 different sessions. A cross-modal magnitude matching procedure was used to scale salt taste-intensity judgments. After each salt test, amiloride (100 microns) was delivered for 5 min and the test was repeated. At least-square regression analysis of each subjects' function between log molar concentration and log response demonstrated that every subject scaled the dynamic range of salts. There were no differences in either the mean regression or intercept among the 3 salts. Repeated-measures analysis demonstrated a statistical effect of amiloride on the before/after difference in the regression (p = 0.02) and intercept (p < 0.0001) of NaCl and LiCl functions. Postamiloride NaCl and LiCl coefficient of variance of response was increased. Amiloride had no effect on the before/after difference in the regression and intercept of KCl power functions or the variance of response. The results suggest that, after amiloride, NaCl and LiCl suprathreshold salt taste intensities are reduced, but there are individual variabilities of reduced intensity that are never completely eliminated.

3,4,5-Trihydroxy benzoic acid (gallic acid), the hepatoprotective principle in the fruits of Terminalia belerica-bioassay guided activity.

Compound I isolated from fraction TB5 of Terminalia belerica and finally identified as 3,4,5-trihydroxy benzoic acid (gallic acid) was evaluated for its hepatoprotective activity against carbon tetrachloride (CCl4)-induced physiological and biochemical alterations in the liver. The main parameters studied were hexobarbitone-induced sleep, zoxazolamine induced paralysis, serum levels of transaminases and bilirubin. The hepatic markers assessed were lipid peroxidation, drug metabolising enzymes, glucose-6-phosphatase and triglycerides. Administration of Compound I led to significant reversal of majority of the altered parameters. Our results confirm the presence of hepatoprotective activity in altered parameters. Our results confirm the presence of hepatoprotective activity in Compound I.

Hepatoprotective effects of Eclipta alba on subcellular levels in rats.

The hepatoprotective effect of the ethanol/water (1:1) extract of Eclipta alba (Ea) has been studied at subcellular levels in rats against CCl4-induced hepatotoxicity. Ea significantly counteracted CCl4-induced inhibition of the hepatic microsomal drug metabolising enzyme amidopyrine N-demethylase and membrane bound glucose 6-phosphatase, but failed to reverse the very high degree of inhibition of another drug metabolising enzyme aniline hydroxylase. The loss of hepatic lysosomal acid phosphatase and alkaline phosphatase by CCl4 was significantly restored by Ea. Its effect on mitochondrial succinate dehydrogenase and adenosine 5'-triphosphatase was not significant. The study shows that hepatoprotective activity of Ea is by regulating the levels of hepatic microsomal drug metabolising enzymes.

Structure and hepatoprotective activity of a biflavonoid from Canarium manii.

Canarium manii (Burseraceae) was chemically investigated and the presence of the biflavonoid agathisflavone is reported for the first time from this plant. Pharmacologically, this biflavonoid in doses 50.0 mg and 100.0 mg given orally exhibited dose-dependent hepatoprotective activity against experimentally-induced carbon tetrachloride-hepatotoxicity in rats and mice.

Evaluation of xanthotoxol for central nervous system activity.

Xanthotoxol (XT), 8-hydroxypsoralen, exhibited dose-graded sedative activity in dogs, cats, rats, mice and hamsters. At doses of 5-20 mg/kg intraperitoneally (i.p.) in cats and 3-100 mg/kg orally (p.o.) in dogs, XT blocked predatory mouse/rat killing behavior. In mice, XT (10-300 mg/kg i.p.) exhibited a dose-dependent reduction in locomotor activity but was less potent in this regard than reference diazepam (10-100 mg/kg i.p.). XT in mice (0.1-10.0 mg/kg i.p.) and in hamsters (0.1-10.0 mg/kg p.o.) antagonized amphetamine-induced hypermobility but was less potent than diazepam. XT elevated the electrical threshold in foot-shock-induced fighting behavior in rats. XT (0.1-30.0 mg/kg p.o.) potentiated pentobarbital-induced narcosis in hamsters at otherwise subeffective doses of pentobarbital. Conditioned avoidance responses in rats were not significantly altered with 1-3 mg/kg i.p. and 30-100 mg/kg p.o. doses of XT but 300 mg/kg p.o. blocked both conditioned and unconditioned response. Doses of 100-1000 mg/kg i.p. of XT in mice were used to study 48-h acute toxicity of XT and its LD50 was estimated to be 468 mg/kg. Doses of 10, 40 and 80 mg/kg p.o. were used to study the chronic toxicity of XT in rats for 6 months and no side effects or abnormalities in reproductive activity or endocrine integrity were noted. The F1 generation of rats from 6-month XT-treated parents were free of teratogenic effects.

An evaluation of Lawsonia alba extract as hepatoprotective agent.

The hepatoprotective activity of an ethanol-water (1:1) extract of Lawsonia alba has been studied against CCl4-induced liver toxicity. The effects of the extract on hexobarbitone-induced sleep, BSP clearance, and on certain biochemical parameters indicated its protective role. There was no effect on bile flow. The extract did not show any signs of toxicity and the minimum lethal dose was greater than 2.0 g/kg p.o. in mice.

Boerhaavia diffusa: a study of its hepatoprotective activity.

An alcoholic extract of whole plant Boerhaavia diffusa given orally exhibited hepatoprotective activity against experimentally induced carbon tetrachloride hepatotoxicity in rats and mice. The extract also produced an increase in normal bile flow in rats suggesting a strong choleretic activity. The extract does not show any signs of toxicity up to an oral dose of 2 g/kg in mice.

Effect of Zizyphus sativa leaves on blood glucose levels in normal and alloxan-diabetic rats.

An alcoholic extract of Zizyphus sativa leaves was tested for hypoglycemic activity in normal and alloxan-diabetic rats. Single (100-400 mg/kg) oral doses of extract to normal animals showed a dose-dependent statistically significant lowering of blood glucose 2, 4 and 6 h later. The effect was most pronounced at 6 h with blood glucose returning to control values at 24 h. In alloxan-diabetic rats, no significant effect was observed with extract and tolbutamide. The minimum lethal dose was greater than 3000 mg/kg, orally in mice.

Hepatoprotective effects of Wedelia calendulacea.

The alcoholic extract of whole plant Wedelia calendulacea exhibited protective activity against carbon tetrachloride-induced liver injury in vivo. The extract also increased the bile flow in rats suggesting a stimulation of liver secretory capacity. The minimum lethal dose was greater than 200 mg/kg p.o. in mice.