brazilein and Reperfusion-Injury

To investigate brazilein's role in energy metabolism of cerebral ischemia-reperfusion in mice.. Fourty mice were randomly divided into the sham group, ischemia group, brazilein 5 mg x kg(-1) group and brazilein 10 mg x kg(-1) group, each with ten cases. Cerebral ischemia model was the built. Mice were injected with brazilein three days before the operation, then they were killed. Cerebrum homogenate was prepared for the detecting of ATP, ADP, AMP and lactic acid by HPLC, expressions of MCT1 and MCT2 in mRNA level by RT-PCR.. The lactic acid in cerebrum increased sharply 20 minutes after cerebral ischemia and decreased 1 hour after reperfusion, then returned to the normal level 24 hours after reperfusion. The charge of energy decreased significantly at the beginning of the ischemia-reperfusion, and the charge restored 1 hour after reperfusion though it was still much lower than the normal level at the time point of 24 hours. Moreover, MCT1 and MCT2 upregulated accompanied with the increase of lactate, MCT2 mRNA enhanced in brazilein 5 mg x kg(-1) group (P < 0.05) while both the two factors increased in brazilein 10 mg x kg(-1) group (P < 0.01).. Brazilein might protect neurons by changing the charge of energy.

Topics: Animals; Benzopyrans; Brain Ischemia; Disease Models, Animal; Energy Metabolism; Gene Expression; Humans; Indenes; Male; Mice; Mice, Inbred ICR; Monocarboxylic Acid Transporters; Random Allocation; Reperfusion Injury; Symporters

Brazilein isolated from Caesalpinia sappan was evaluated for neuroprotection against transient focal cerebral ischemia/reperfusion in rats. The results showed that administration of brazilein after the onset of cerebral ischemia reperfusion can reduce the brain infarction area and improve the neurological score. The mechanisms underlying the action were investigated and attributed to the anti-inflammatory effect of brazilein, because a decrease of the mRNA level of pro-inflammatory cytokines (tumor necrosis factor-alpha(TNF-alpha) and interleukin-6 (IL-6)) was found in the ischemic animals with brazilein treatment. To further substantiate the anti-inflammatory effect of brazilein, we examined the mRNA expression of the cytokines in the lipopolysaccharide (LPS) induced microglial cell line BV2 cells; TNF-alpha and IL-6 mRNA expressions were significantly suppressed by brazilein treatment but the decrease of interleukin-1beta (IL-1beta) expression was not detected. Nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS), another indicator of the inflammatory response of the immune cells was measured in RAW 264.7 macrophages and BV2 cells; brazilein inhibited its production induced by LPS in both types of cells in a dose-dependent manner. Consistently, the mRNA level of iNOS was also decreased by brazilein. Together, these results illustrate that brazilein can protect the brain against ischemia/reperfusion injury and the anti-inflammatory effect was believed to be one of the contributive mechanisms.

Topics: Animals; Anti-Inflammatory Agents; Benzopyrans; Brain Ischemia; Cerebral Infarction; Cytokines; Indenes; Male; Mice; Nitric Oxide; Nitric Oxide Synthase Type II; Rats; Rats, Wistar; Reperfusion Injury; RNA, Messenger