Effect of herbo-mineral formulation EHb in experimental anaemia in rodents.

EHb-a herbo-mineral formulations of iron (ferrous form) produced a significantly higher and dose dependent increase in the haemoglobin level, as compared to Fefol (a non-complex-chelated iron preparation). Also, EHb did not produce any overt toxicity or gastric irritation at these dose levels. The results suggest that EHb can be of a better choice in the treatment of anaemia than any other commercially available chelated iron preparations.

Experimental methods for evaluation of psychotropic agents in rodents: II-Antidepressants.

Rodent models of clinical depression are extensively used for the evaluation of putative antidepressants. In the present review, the available experimental methods which can be utilized by most laboratories involved in preclinical screening of antidepressants, have been discussed. The methods have been categorized on the basis of induction of the depressive state or on the assumption that monoamine deficiency leads to depression. These methods have been critically validated in terms of efficacy of standard antidepressants in these tests and, in some cases, by the neurochemical basis of depression, namely, the deficient monoaminergic theory of clinical depression.

Comparative effects of prenatal and postnatal undernutrition on learning and memory in rats.

Effects of pre- and post-natal undernutrition on learning and memory parameters were studied in albino rats. Prenatal undernutrition was induced in rat pups by restricting the mother's diet by 50% during the entire gestation period, whereas postnatal undernutrition was induced in rat pups by restriction of their diet by rotating them between lactating and non-lactating maternalised females for 12 hr each day during suckling period from 2nd day to 18th day after birth. At 2.5 to 3 months of age all the rat offsprings were subjected to (i) original and reversal discrimination learning, (ii) passive avoidance, and (iii) active avoidance and its retention tests. The results indicate that both pre- and post-natal undernutrition in rat pups caused significant deficits in original and reversal discrimination learning, retention of passive avoidance after one week retention interval, and retention of active of avoidance learning. However, both pre- and post-natal undernutrition did not show significant effect on acquisition of active avoidance and retention of passive avoidance after 24 hr retention interval.

Experimental methods for evaluation of psychotropic agents in rodents: I--Anti-anxiety agents.

Rodent models of clinical anxiety are extensively used for evaluating putative anxiolytic activity. In the present review, the available methods which can be utilized by most laboratories, have been discussed. These methods have been categorized as methods involving conditioning techniques and those not involving conditioning. In most cases, the methodology has been briefly discussed in terms of experimental use and efficacy of benzodiazepine and the newer non-benzodiazepine anxiolytics.

Antioxidant activity of glycowithanolides from Withania somnifera.

Antioxidant activity of active principles of Withania somnifera, consisting of equimolar concentrations of sitoindosides VII-X and withaferin A, was investigated for their effects on rat brain frontal cortical and striatal concentrations of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). Results were compared with effects induced by deprenyl, an agent with well documented antioxidant activity. Active glycowithanolides of W. somnifera (WSG) (10 and 20 mg/kg, i.p.), administered once daily for 21 days, induced a dose-related increase in SOD, CAT and GPX activity in frontal cortex and striatum, which was statistically significant on days 14 and 21, except with the lower dose of WSG on GPX activity, where the effect was evident only on day 21. The data were comparable to those induced by deprenyl (2 mg/kg/day, i.p.) with respect to SOD, CAT and GPX activities, which were evident by day 14. These findings are consistent with the therapeutic use of W. somnifera as an Ayurvedic rasayana and medhyarasayana. Antioxidant effect of active principles of W. somnifera may explain, at least in part, the reported antistress, immunomodulatory, cognition-facilitating, anti-inflammatory and anti-aging effects produced by them in experimental animals, and in clinical situations.

Effect of Trasina, an Ayurvedic herbal formulation, on pancreatic islet superoxide dismutase activity in hyperglycaemic rats.

Diabetes mellitus was induced in male CF strain rats by streptozotocin (STZ) and hyperglycaemia and superoxide dismutase (SOD) activity of pancreatic islet cells was assessed on days 7, 14, 21 and 28. STZ induced significant hyperglycaemia and a concomitant decrease in islet cell SOD activity. Transina (TR), an Ayurvedic herbal formulation comprising of Withania somnifera, Tinospora cordifolia, Eclipta alba, Ocimum sanctum, Picrorrhiza kurroa and shilajit, had little per se effect on blood sugar concentrations and islet SOD activity in euglycaemic rats, in the doses of 100 and 200 mg/kg, p.o. administered once daily for 28 days. However, these doses of TR induced a dose- related decrease in STZ hyperglycaemia and attenuation of STZ induced decrease in islet SOD activity. The results indicate that the earlier reported anti-hyperglycaemic effect of TR may be due to pancreatic islet free radical scavenging activity, the hyperglycaemic activity of STZ being the consequence of decrease in islet SOD activity leading to the accumulation of degenerative oxidative free radicals in islet beta-cells.

Behavioural effects of prenatal and postnatal undernutrition in rats.

Effects of pre- and post-natal undernutrition on anxiety and depression paradigms were studied in albino rats. Prenatal undernutrition was induced in rat pups by restricting the dam's daily food during the gestation period whereas postnatal undernutrition in rat pups was induced by rotating them between lactating and non-lactating maternalised females daily for 12 hr during suckling period from 2nd to 18th day after birth. At 2.5 to 3 months of age all the rat pups were subjected to (i) elevated plus maze behaviour, (ii) open-field behaviour, and (iii) swimming induced behavioural despair tests. The results indicate that postnatal undernutrition caused significantly increased anxiety in the elevated plus maze as well as in open-field behaviour tests. Whereas prenatal undernourishment caused lesser degree of anxiogenic behaviours in the elevated plus maze test. Prenatally undernourished rats showed increased anxiety in the open-field behaviour test. Both, pre- and post-natal undernutrition also lead to increased depressive behaviour in the behavioural despair test and postnatal undernourishment caused greater degree of behavioural despair.

Isatin, a putative anxiogenic endocoid, induces memory dysfunction in rats.

Isatin (2,3-dioxoindole), one of the components of tribulin, which has been postulated to function as an endogenous marker of stress and anxiety, was shown to induce a dose-related attenuation of learning acquisition in an active avoidance test and inhibition of learning retention, or memory, in a step-down passive avoidance paradigm and transfer latency in an elevated plus-maze, in rats. Earlier studies have indicated that isatin functions as a 5-hydroxytryptamine (5-HT)3 receptor agonist in its anxiogenic activity in rats and is an antagonist at mammalian atrial natriuretic peptide (ANP) receptors. Since 5-HT3 receptor antagonists and centrally administered ANP have been shown to facilitate learning and memory, the observed memory dysfunction induced by isatin can be attributed to its receptor activity at 5-HT3 and ANP receptors. The investigation also indicates that anxiogenic agents are likely to disrupt memory functions.