Impact of pre-exposure of tail suspension on behavioural parameters like locomotion, exploration, and anxiety in mice.

The tail suspension test (TST) is a valid tool for assessing antidepressant activity. Association between depression and lower locomotion and exploration activities is also reported. In the present study, photoactometer, hole board and elevated plus maze tests were performed to evaluate locomotion, exploration and anxiety activities on animals of first and second set, however animals of second set were pre-exposed to TST. The comparison between these two sets will help in understanding the impact of pre-exposure to TST on behavioural parameters. In both sets, swiss albino mice were treated with caffeine (10 mg/kg, ip), bupropion (10 mg/kg, ip), duloxetine (10 mg/kg, ip), nicotine (0.8 mg/kg, sc) and normal saline. Control group of second set showed significant decrease in locomotion, exploration and increase in anxiety when compared against control group of first set. In second set, duloxetine, bupropion, and nicotine treated groups showed significant increase in locomotion when compared against control group of same set. Overall, pre-exposure to TST leads to significant decrease in locomotion, exploration activities and increase in anxiety level. Further studies demonstrating it’s time bound impact on brain monoamine levels with correlation to behavioural paradigms may help to validate these outcomes.

Effects of Gmelina arborea extract on experimentally induced diabetes

OBJECTIVE@#To study the effects of aqueous extract of Gmelina arborea bark on normoglycemic levels and streptozotocin (STZ) induced diabetes in rats.@*METHODS@#After single administration of the aqueous extract, plasma glucose level was determined up to 6 h. In subacute study, the aqueous extract was administered for 28 d and plasma glucose level was determined weekly. The diabetes was induced in rats by the intraperitoneal injection of STZ at a dose of 55 mg/kg body weight. The diabetic animals were divided into four groups containing six in each: Group I diabetic control, Group II and III treated with the aqueous extract respectively at a dose of 250 and 500 mg/kg body weight once daily and Group IV treated with glibenclamide at a dose of 0.6 mg/kg body weight once daily. In acute study, the aqueous extract and glibenclamide were administered orally to rats. Plasma glucose levels were determined at 30, 60, 120, 240 and 360 min after the administration of the test samples. To study subacute effects, test samples (the aqueous extract and glibenclamide) were administered for 28 d consecutively. The effects of each test sample on plasma glucose level, body weight as well as food and water intake were also monitored weekly. The oral glucose tolerance test and biochemical indicators were estimated on day 28.@*RESULTS@#The aqueous extract did not significantly decrease the plasma glucose level in the normoglycemic rats as shown by the acute and subacute assays. However, after oral administration of the aqueous extract, the plasma glucose level was significantly (P<0.001) decreased in the diabetic rats in the acute study. The long-term administration of the aqueous extract significantly (P<0.001) reduced plasma glucose levels of the diabetic rats. Additionally, the aqueous extract also reduced loss of body weight and significantly decreased food and water intake in the diabetic animals. Nevertheless, no effects on biochemical indicators were observed at the selected doses.@*CONCLUSIONS@#The aqueous extract of Gmelina arborea bark had antihyperglycemic activity against STZ induced diabetes in rats, after single and subacute oral administration. Moreover, it did not show significant glucose lowering effect in normoglycemic rats.