Bhattacharya Sk

Antioxidant activity of Bacopa monniera in rat frontal cortex, striatum and hippocampus.

The effect of a standardized extract of Bacopa monniera Linn. was assessed on rat brain frontal cortical, striatal and hippocampal superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) activities, following administration for 7, 14 or 21 days. The effects induced by this extract (bacoside A content 82%u2005±u20050.5%), administered in doses of 5 and 10u2005mg/kg, orally, were compared with the effects induced by (−) deprenyl (2u2005mg/kg, p. o.) administered for the same time periods. Bacopa monniera (BM) induced a dose‐related increase in SOD, CAT and GPX activities, in all the brain regions investigated, after 14 and 21 days of drug administration. On the contrary, deprenyl induced an increase in SOD, CAT and GPX activities in the frontal cortex and striatum, but not in the hippocampus, after treatment for 14 or 21 days. The results suggest that BM, like deprenyl, exhibits a significant antioxidant effect after subchronic administration which, unlike the latter, extends to the hippocampus as well. The results suggest that the increase in oxidative free radical scavenging activity by BM may explain, at least in part, the cognition‐ facilitating action of BM, recorded in Ayurvedic texts, and demonstrated experimentally and clinically. Copyright

Anti-oxidant effect of Withania somnifera glycowithanolides in chronic footshock stress-induced perturbations of oxidative free radical scavenging enzymes and lipid peroxidation in rat frontal cortex and striatum.

The antioxidant activity of Withania somnifera (WS) glycowithanolides was assessed in chronic footshock stress induced changes in rat brain frontal cortex and striatum. The stress procedure, given once daily for 21 days, induced an increase in superoxide dismutase (SOD) and lipid peroxidation (LPO) activity, with concomitant decrease in catalase (CAT) and glutathione peroxidase (GPX) activities in both the brain regions. WS glycowithanolides (WSG), administered orally 1 h prior to the stress procedure for 21 days, in the doses of 10, 20 and 50 mg/kg, induced a dose-related reversal of the stress effects. Thus, WSG tended to normalise the augmented SOD and LPO activities and enhanced the activities of CAT and GPX. The results indicate that, at least part of chronic stress-induced pathology may be due to oxidative stress, which is mitigated by WSG, lending support to the clinical use of the plant as an antistress adaptogen.

Immobilisation stress-induced antinociception in rats: Possible role of serotonin and prostaglandins

Immobilisation of rats for 1, 2 and 4 h induced duration-related antinociception. Antinociception induced by 4 h immobilisation was significantly inhibited after pretreatment by drugs known to inhibit synthesis of serotonin, induce degeneration of serotonergic neurones and inhibit prostaglandin synthesis. The results indicate that immobilisation stress induces autoanalgesia, which may be dependent on the availability of endogenous serotonin and prostaglandins in rat brain.

Effect of Withania somnifera glycowithanolides on iron-induced hepatotoxicity in rats

Glycowithanolides, consisting of equimolar concentrations of sitoindosides VII–X and withaferin A, isolated from the roots of Withania somnifera Dunal, have been reported to have an antioxidant effect in the rat brain frontal cortex and striatum. In the present study, the effect of 10 days of oral administration of these active principles, in graded doses (10, 20 and 50u2005mg/kg), was noted on iron overload (FeSo4, 30u2005mg/kg, i.p.) induced hepatotoxicity in rats. Apart from hepatic lipid peroxidation (LPO), the serum enzymes, alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase, were assessed as indices of hepatotoxicity. Silymarin (20u2005mg/kg, p.o.) was used for comparison. Iron overload induced marked increase in hepatic LPO and serum levels of the enzymes, which was attenuated by WSG in a dose‐related manner, and by silymarin. The results indicate that the reported use of WS in Ayurveda for hepatoprotection against heavy metals and other environmental toxins, may be due the antioxidant action of WSG. Copyright

Effect of bioactive tannoid principles of Emblica officinalis on iron- induced hepatic toxicity in rats

The tannoid principles of the fruits of the plant Emblica officinalis Gaertn comprising of emblicanin A. emblicanin B, punigluconin and pedunculagin, have been reported to exhibit antioxidant activity in vitro and in vivo. In the present study, an emblicanin A (37%) and B (33%) enriched fraction of fresh juice of Emblica fruits (EOT), administered prophylactically (10, 20 and 50 mg/kg, p.o.) for 10 consecutive day, was found to inhibit acute iron overload (30 mg/kg, i.p.) hepatic lipid peroxidation and the increase of serum levels of alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase, used as markers of the induced hepatic dysfunction. A similar effect was produced by silymarin (20 mg/kg, p.o.), an antioxidant hepatoprotective agent. The results support the use of Emblica fruits for hepatoprotection in Ayurveda.

Potentiation of gastric toxicity of ibuprofen by paracetamol in the rat

Abstract— A fixed dose combination of ibuprofen (400 mg) and paracetamol (325 mg) is by far the most extensively prescribed medicament for a variety of musculoskeletal disorders in India. Following clinical observations that this drug combination induces significant adverse effects, its gastric toxicity was investigated in rats. Ibuprofen (25 mg kg−1 p.o., twice daily × 5 days), paracetamol (20 mg kg−1 p.o, twice daily × 5 days), and a combination of the two, had no significant effect on free and total gastric acidity in pylorusligated rats. Ibuprofen induced visible gastric ulceration whereas paracetamol did not. However, the combination of these two drugs had an additive effect inducing severe gastric erosions, ulcerations and bleeding. The augmented toxicity of this drug combination appeared to be a consequence of attenuated gastric mucin activity and reduction in the gastric muco‐protective barrier. This investigation indicates the likely hazard of an irrational fixed dose drug combination.