Teratogenic Potential of Thymoquinone [the main constituent of the Black Seed] in Rats

This study investigated embryotoxic and teratogenic effects of thymoquinone, the main constituent of the Black Seed [Nigella sativa]. All tests were done on rats. Pregnant rats were treated with various doses of thymoquinone [3.12, 6.25,12.5 and 25 mgkg, i.p.] from 7[th] to 16[th] day of gestation. Different doses of thymoquinone [TQ] did not induce any significant changes in fetal sex ratio, resorptions and litter size. Gross external malformations were not observed. Lower doses of TQ [3.12 and 6.25 mg/kg] significantly, retarded neonatal body weights. Higher doses [12.5 and 25 mg/kg] seemed to be safe, as they did not affect fetal growth. In conclusion, this study showed that low doses of TQ [3.125 and 6.25 mg/kg, i.p.] were f etotoxic in rats

Effect of valproic acid on food intake and nociception in morphine dependent mice

The anorectic and antinociceptive effects or valproic acid [VPA] were studied in morphine-dependent rnice in comparison with normal ones. For this purpose, the food intake of animals deprived of food for 24 hours and the hot plate reaction time, were studied. Morphine-dependency was induced by i.p. injections of morphine HC1 [40 mg /kg; twice daily for 3 days]. Morphine-dependent animals showed a significant decrease in food intake [p < 0.05], when compared with control mice [non-morphinized]. Acute administration of VPA [100, 200 and 300 mg /kg, i.p.] significantly potentiated the anorexia observed in morphine-dependent mice. VPA [200 and 300 mg /kg, i.p.] alone produced a significant decrease in food intake [p < 0.05] in non-morphinized animals, in the study of antinociception, a significant increase [p < 0.001] in hot-plate latency was observed in morphine-dependent animals, as compared to control mice. Treatment with VPA alone produced a significant increase [p < 0.05] in hot-plate latency in saline-pretreated animals in comparison with saline-pretreated control group. However, the administration of VPA [100 and 200 mg /kg, i.p.] to morphine-dependent animals significantly decreased [p < 0.05] their hot-plate latency as compared to the control group, in conclusion, VPA exhibited anorectic and antinociceptive activities in mice. VPA potentiated the anorexia seen in mice, which were rendered dependent to morphine, whereas the drug inhibited the antinociceptive activity observed in these mice. It seems from the present study that VPA is probably toxic in morphine-dependent subjects, since it might potentiate the anorectic and inhibit the analgesic effects

Serotonin Receptor Antagonists Nan-190, Methiothepin, Methysergide, Mianserin Or Ondansetron protect against Methamphetamine-Induced Hyperthermia in mice

The effect of some serotonin receptor antagonists was investigated on the body temperature of male mice. These antagonists produced significant reductions of body temperature in methamphetamine-induced hyperthermic male mice. Thus, the hyperthermia induced by metha-mphetamine [11 mol/kg,i.p..] was antagonized by the previous i.p. administration of 1.06 Amol/kg NAN-190 [5-HTIA receptor antagonist], 22.1 Amol/kg methiothepin [5-HT IB/ID receptor antagonist], 2.13 iimol/kg methysergide [5-HT 2,v2B receptor antagonist], 3.3 ktmol/kg mianserin [5-HT2c and a2 - adrenoceptor antagonist] or 0.003 Amol/kg ondansetron [5-HT3 receptor antagonist]. The present results indicate that central serotonin receptors may he involved in the hyperthermic effect of methamphetamine. Ondansetron, being effective at a relatively small dose [0.003 Amol/kg] as compared to other antagonists used in this study, may be a potential antidote for methamphetamine-induced hyperthermia