The antinociceptive effect of artemisinin on the inflammatory pain and role of GABAergic and opioidergic systems / 대한통증학회지

BACKGROUND: Pain is a complex mechanism which involves different systems, including the opioidergic and GABAergic systems. Due to the side effects of chemical analgesic agents, attention toward natural agents have been increased. Artemisinin is an herbal compound with widespread modern and traditional therapeutic indications, which its interaction with the GABAergic system and antinoniceptive effects on neuropathic pain have shown. Therefore, this study was designed to evaluate the antinociceptive effects of artemisinin during inflammatory pain and interaction with the GABAergic and opioidergic systems by using a writhing response test. METHODS: On the whole, 198 adult male albino mice were used in 4 experiments, including 9 groups (n = 6) each with three replicates, by intraperitoneal (i.p.) administration of artemisinin (2.5, 5, and 10 mg/kg), naloxone (2 mg/kg), bicuculline (2 mg/kg), saclofen (2 mg/kg), indomethacin (5 mg/kg), and ethanol (10 mL/kg). Writhing test responses were induced by i.p. injection of 10 mL/kg of 0.6% acetic acid, and the percentage of writhing inhibition was recorded. RESULTS: Results showed significant dose dependent anti-nociceptive effects from artemisinin which, at a 10 mg/kg dose, was statistically similar to indomethacin. Neither saclofen nor naloxone had antinociceptive effects and did not antagonize antinociceptive effects of artemisinin, whereas bicuculline significantly inhibited the antinocicptive effect of artemisinin. CONCLUSIONS: It seems that antinocicptive effects of artemisinin are mediated by GABAA receptors.

Effects of Ghrelin on germ cell apoptosis and proinflammatory cytokines production in Ischemia-reperfusion of the rat testis

Testicular torsion is a medical emergency that requires surgical intervention to reperfuse the affected testis. Ischemia reperfusion injury is usually associated with proinflammatory cytokine generation and apoptosis of germ cells in the testes. In this study we investigate the effect of ghrelin on the proinflammatory cytokines levels and germ cell apoptosis in testicular ischemia reperfusion. 45 male rats were selected for the study and randomly divided into 3 groups, each containing 15 rats. Animals in the testicular torsion and ghrelin treated groups were subjected to unilateral 720 counterclockwise testicular torsion for 1 hr and then reperfusion was allowed after detorsion for 4 hr, 1 and 7 days. The ghrelin-treated group received intraperitoneal injection of ghrelin 15min before detorsion. The expression levels of bcl-2-associated X protein and proliferating cell nuclear antigen in testicular tissue in the different groups were detected by immunohistochemical assay and tissue cytokines interleukin-1beta, tumor necroses factor-alpha and interleukin-6 were measured using enzyme-linked immunosorbent assay. After being treated by ghrelin, the population of immunoreactive cells against BAX in the spermatocytes on day 7 after reperfusion significantly decreased when compared to tortion/ detortion-saline animals [p=0.024]. In contrast, PCNA expression in the spermatocytes and spermatogonia were not significantly different between tortion/ detortion-ghrelin and tortion/ detortion-saline groups on both experimental days. Administration of ghrelin significantly attenuated the testicular tumor necroses factor-alpha and interleukin-6 levels compared with the untreated animals, but had no significant effect on the level of interleukin-1beta. Ghrelin offers remarkable anti-inflammatory and anti-apoptotic effects in testicular ischemia reperfusion injury

The effect of melanocortin (Mc3 and Mc4) antagonists on serotonin-induced food and water intake of broiler cockerels

The current study was designed to examine the effects of intracerebroventricular injections of SHU9119 [a nonselective melanocortin receptor (McR) antagonist] and MCL0020 (a selective McR antagonist) on the serotonin-induced eating and drinking responses of broiler cockerels deprived of food for 24 h (FD24). For Experiment 1, the chickens were intracerebroventricularly injected with 2.5, 5, and 10 microg serotonin. In Experiment 2, the chickens received 2 nmol SHU9119 before being injected with 10 microg serotonin. For Experiment 3, the chickens were given 10 microg serotonin after receiving 2 nmol MCL0020, and the level of food and water intake was determined 3 h post-injection. Results of this study showed that serotonin decreased food intake but increased water intake among the FD24 broiler cockerels and that these effects occurred in a dose-dependent manner. The inhibitory effect of serotonin on food intake was significantly attenuated by pretreatment with SHU9119 and MCL0020. However, the stimulatory effect of serotonin on water intake was not altered by this pretreatment. These results suggest that serotonin hypophagia and hyperdipsia were mediated by different mechanisms in the central nervous system, and that serotonin required downstream activation of McRs to promote hypophagia but not hyperdipsia in the FD24 chickens.