A novel series of thromboxane A2 synthetase inhibitors with free radical scavenging and anti-peroxidative activities

Edaravone attenuates sustained pial arteriolar vasoconstriction independently of the endothelial function after unclamping of an abdominal aorta in rabbits

Background

Cerebral blood flow (CBF) has direct impacts on the neuronal function and neurocognitive disorder. Oxidative stress from abdominal aortic surgery is important in the pathophysiology of CBF impairment. We investigated whether oxidative damage from abdominal aortic surgery is associated with reduced CBF and whether vascular endothelial dysfunction modifies these associations.

Methods

Rabbit closed cranial window preparation was used to measure changes in the pial arteriolar diameter after unclamping following abdominal aortic cross-clamping with an intravenous free radical scavenger, edaravone (control group, n=6; edaravone 10 μg/kg/min, n=6; 100 μg/kg/min, n=6). The pial vasodilatory responses to the topical application of acetylcholine (ACh) into the cranial window were investigated before abdominal aortic cross-clamping and after unclamping with the intravenous administration of edaravone (control group, n=6; edaravone 100 μg/kg/min, n=6).

Results

The aortic unclamping-induced vasoconstriction was significantly attenuated under the continuous infusion of edaravone at 100 μg/kg/min. The topical application of ACh after unclamping did not produce any changes in pial arteriolar responses in comparison to before aortic cross-clamping in the control or edaravone groups. The changes in the response to topical ACh after unclamping in the saline and edaravone groups did not differ to a statistically significant extent.

Conclusions

Free radicals during abdominal aortic surgery might have contracted cerebral blood vessels independently of the endothelial function in rabbits. The suppression of free radicals attenuated sustained pial arteriolar vasoconstriction after aortic unclamping. Thus, the free radical scavenger might have some brain protective effect that maintains the CBF independently of the endothelial function.

Effects of vinpocetine and ozagrel on behavioral recovery of rats after global brain ischemia

Brain ischemia leads to severe disruption of the nervous system and recovery is often prolonged. Rehabilitative post-ischemia pharmacological treatment may therefore be important for behavioral recovery, especially for cognition and motor behavior. The present study investigated the effects of combined vinpocetine and ozagrel administration on the behavioral recovery of rats from global brain ischemia. The results suggest that the combined treatment leads to significantly better improvement compared to single drug administration. We conclude that the combined use of vinpocetine and ozagrel may provide beneficial effects to patients suffering from brain ischemia.

Preventive efficacy of hydroalcoholic extract of Cymbopogon citratus against radiation-induced DNA damage on V79 cells and free radical scavenging ability against radicals generated in vitro

This study presents the findings of free radical scavenging and antigenotoxic effect of hydroalcoholic extract of Cymbopogon citratus (CCE). The CCE at a concentration of 60 μg/mL resulted in a significant scavenging ability of 2,2-diphenyl-2-picryl hydrazyl (DPPH; (85%), 2,2-azinobis (3-ethyl benzothiazoline-6-sulphonic acid) (ABTS; 77%), hydroxyl (70%), superoxide (76%), nitric oxide (78%) free radicals generated using in vitro and also a moderate anti-lipid peroxidative effect (57%). Further, the radiation-induced antigenotoxic potential of CCE was assessed in Chinese hamster lung fibroblast cells (V79) using micronucleus assay. The CCE resulted in a dose-dependent decrease in the yield of radiation-induced micronuclei, with a maximum effect at 125 μg/mL CCE for 1 h before 2 Gy of radiation. Similarly, there was a significant ( P < 0.05–0.0001) decrease in percentage of micronuclei when V79 cells were treated with optimal dose of CCE (125 μg/mL) before exposure to different doses of gamma radiation, that is, 0.5–4 Gy, compared with radiation alone groups. The results of the micronucleus study indicated antigenotoxic effect demonstrating the radioprotective potential of CCE and, which may partly due to its and antioxidant capacity as it presented its ability to scavenge various free radicals in vitro and anti-lipid peroxidative potential.