therapeutic effect of the aqueous extract of boswellia serrata on the learning deficit in kindled rats

It has been reported that epilepsy is a disorder of the central nervous system that causes memory impairment. This study examines the role of the aqueous extract of Boswellia on the learning disability of the pentylenetetrazol [PTZ]-induced kindled rats. In this experimental study, 64 male rats were used. Kindling seizures were induced by three injections of 25 mg/kg of PTZ every 15 min. Control animals received normal saline instead. To evaluate the therapeutic effect of Boswellia extract on the PTZ-induced cognitive deficits, the aqueous extract [0, 0.1, 0.5 or 1 g/kg, i.p.] were administrated to all animals for three consecutive days. At 24 h later, passive avoidance learning of animals was examined using shuttle box apparatus, respectively. The time required for the animal stepping through the dark chamber was determined as step through latency [STL]. Data were subjected to the t-test and analysis of variance and followed by Tukey's test for multiple comparisons. The STL of the kindled rats was significantly reduced compared with control ones [22/375 +/- 4/19 for kindled and 295 +/- 15/71 for control groups, respectively]. Aqueous extract of Boswellia improved passive-avoidance learning ability in both control and PTZ-kindled animals [P < 0.05]. The results can be stated that the Boswellia extract is offset by harmful effects of seizures on cognitive function and consumption of Boswellia extract increases the learning ability in epileptic animals

[Effects of pioglitazone injection into hippocampal CA1 area on spatial learning and memory deficits in rats]

Pioglitazone from thiazolidinediones generation, represent a new antidiabetic drugs that have been introduced in the world recently. Thiazolidinediones can improve insulin resistance by activating the nuclear peroxoxisome proliferator activated receptor-gamma [PPAR-gamma] and increasing insulin sensitivity in their receptors. Insulin and its receptors are found in specific areas of CNS with a variety of region-specific functions. The effects of insulin in CNS are different from its direct glucose regulation in the periphery. Hippocampus and cerebral cortex distributed insulin/insulin receptor have been shown to be involved in brain cognitive functions. In the present study, the effect of pioglitazone microinjection into CA1 region of rat hippocampus using Morris water maze performance has been investigated. In this experimental study, male N-MRI rats were randomly divided into control, DMF [dimethyl formamide] and pioglitazone groups [0.001, 0.01, 0.1, 1, 10 microg/rat]. Drugs were injected [1 microl/rat] into CA1 region bilaterly during 1 min. Thirty minutes after the intrahippocampal injection of drugs, water maze training was started. Pioglitazone had a dose dependent effect. The spatial learning and memory didn't change with lower dose of pioglitazone, but improved with intermediate doses, while they impaired with higher dose. These results suggest that intrahippocampal injection of pioglitazone may have a dose-dependent effect on spatial learning and memory in rats in range of 0.001 to 1 microg/rat

[ effect of sodium salicylate injection on spatial learning and memory of rat]

Cyclooxygenase [COX] enzyme known as a regulatory factor in synaptic plasticity. It has been reported that synaptic plasticity is one of the mechanisms involved in learning and memory processes. In the current study peripheral injection's effects of sodium salicylate [as a non selective COX inhibitor] on spatial learning and memory have been investigated. Four groups of male rats received different doses of sodium salicylate [0, 200, 300, 400 mg/kg; i.p.]. Studies were performed using Morris Water Maze [MWM]. Spatial learning and memory parameters were subjected to the one- and two-way analyses of variance [ANOVAs] followed by Tukey's post hoc test. Data showed that intraperitoneal injection of sodium salicylate had not significant effect on spatial learning parameters [including escape latency and traveled distance to hidden platform in training days]; but administration of high dose of the drug [400 mg/kg] significantly increased the percentage of time that animals spent in the target quadrant in probe trial testing. Peripheral injection of the COX inhibitor has no significant effect on spatial learning; but potentiates spatial memory consolidation using MWM

Analgesic and anti-inflammatory activity of teucrium chamaedrys leaves aqueous extract in male rats

Current study was undertaken to investigate the analgesic and anti-inflammatory effects of the aqueous extract of Teucrium chamaedrys in mice and rats. For evaluating of analgesic and anti-inflammatory activity, we used the carrageenan-and dextran-induced paw oedema, acetic acid-induced writhing, tail flick and formalin pain tests. The extract of T. chamaedrys [50-200 mg/kg] and acetylsalicylic acid [100 mg/kg] produced a significant [P< 0.01] inhibition of the second phase response in the formalin pain model, while only the high dose [200 mg/kg] of the extract showed an analgesic effect in the first phase. The extract also inhibited acetic acid-induced abdominal writhes in a dose-dependent manner. The tail flick latency was dose dependently enhanced by the extract but this was significantly [P< 0.05] lower than that produced by morphine [10 mg/kg]. The extract [25-250 mg/kg] administered 1 hr before carrageenan-induced paw swelling produced a dose dependent inhibition of the oedema. No effect was observed with the dextran-induced oedema model. Results of the phytochemical screening show the presence of alkaloids, flavonoids and triterpenoids in the extract. The data obtained also suggest that the anti-inflammatory and analgesic effects of the extract may be mediated via both peripheral and central mechanisms. The role of alkaloids, flavonoids and triterpenoids will evaluate in future studies