This study was performed to examine whether the brain activities induced by noxious algesic chemical substances in anesthetized animals could be detected by blood oxygen-level-dependent functional magnetic resonance imaging (BOLD-fMRI). Multislice gradient echo images of the primary somatosensory cortex were obtained using a 7.05 T superconducting system and a one-turned surface coil centered over the primary somatosensory cortex of the 1.0%-isoflurane-anesthetized rat. The Z-score t-map of BOLD signals and its time-course analysis revealed that subcutaneous injection of formalin into the left forepaw immediately induced an early response in the contralateral primary sensory cortex lasting for a few minutes, followed by a late response until 20 min after stimulation. In contrast, injection of capsaicin into the left forepaw evoked only the early response. Furthermore, pretreatment with morphine completely abolished these responses induced by the chemical algesic substances. Thus BOLD-fMRI is a useful method to analyze the brain activities of painful stimulation in anesthetized animals.

The health hazards of individual organophosphorus insecticides have been characterized by their acute toxicity, mainly by investigating their cholinesterase inhibition. However, the chronic effects of most of these toxicants on the drug-metabolizing enzymes have not been investigated. Profenofos (O-4-bromo-2-chlorophenyl O-ethyl S-propyl phosphorothioate) is an organophosphorus pesticide widely used in cotton cultivation. In the present study, we investigated the effect of profenofos on male-specific cytochrome P450 (CYP) enzymes in adult Wistar rats. We orally administered 17.8 mg/kg body weight, twice weekly for 65 days. Profenofos downregulated levels of hepatic and testicular CYP2C11 and CYP3A2 mRNA and protein expression. Testicular aromatase (CYP19A) mRNA was decreased in the profenofos-treated rats compared to controls. Overall, the present study suggests that profenofos acts as an endocrine disruptor of male-specific CYP enzymes and affects testosterone concentration, which implicates its deleterious effects on animal or human males chronically exposed to organophosphorus pesticide.

Nigella sativa (family Ranunculaceae ) is an annual plant that has been traditionally used on the Indian subcontinent and in Middle Eastern countries. In this study, we investigated the effect of N. sativa oil on the drug-metabolizing cytochrome P450 (CYP) enzymes and whether it has a protective effect against the acute hepatotoxicity of CCl4. Intraperitoneal injection of rats with CCl4 drastically decreased CYP2E1, CYP2B, CYP3A2, CYP2C11, and CYP1A2 mRNA and protein expressions. Oral administration of 1 ml/kg N. sativa oil every day for one week prior to CCl4 injection alleviated CCl4-induced suppression of CYP2B, CYP3A2, CYP2C11, and CYP1A2. Moreover, CCl4 increased iNOS and TNFalpha mRNA, while N. sativa oil administration for one week prior to CCl4 injection downregulated the CCl4-induced iNOS mRNA and up-regulated IL-10 mRNA. These results indicate that N. sativa oil administration has a protective effect against the CCl4-mediated suppression of hepatic CYPs and that this protective effect is partly due to the downregulation of NO production and up-regulation of the anti-inflamnatory IL-10.