By regulating IP3/PKC/TRPV4 pathway hyperoside induces endothelium-dependent vasodilatation in rat basilar artery following four vessel occlusion ischemia reperfusion

OBJECTIVE To investigate regulatory effects of hyperoside(Hyp)on IP3/PKC/TRPV4 pathway in rat cerebral basilar artery(CBA)subjected to global cerebral ischemia-reperfusion(I/R).METHODS The model of global cerebral I/R in rats was established by four-vessel occlusions methods.The treated rats were administrated with Hyp(50 mg·kg^-1)group,Hyp(50 mg·kg^-1)+HC-067047(10 mg·kg^-1),Hyp(50 mg·kg^-1)+2APB(2 mg·kg^-1),Hyp(50 mg·kg^-1)+BisI(2.5 mg·kg^-1),Hyp(50 mg·kg^-1)+2APB(2 mg·kg^-1)+BisI(2.5 mg·kg^-1).Hematoxylin-eosin(HE)and Nissl staining were performed and the contents of methane dicarboxylic aldehyde(MDA),neuron-specific enolase(NSE),S100β and the activity of lactic dehydrogenase(LDH)in serum were measured by enzyme-linked immunosorbnent assay(ELISA).The specific blocker N-nitro-L-arginine-methyl-ester(L-NAME)and indomethacin(Indo)were used to delete the prostacyclin(PGI2)and nitric oxide(NO)dependent relaxation.The protein expression level of TRPV4 was detected by Western blotting.Ca2+intensity in vascular smooth muscle cells was measured by confocal laser scanning microscope and flow cytometry was performed to observe the apoptosis of CBA endothelial cells after in vivo administration.RESULTS Hyp induced a dose-dependent relaxation of CBA in IR rats via a PGI2 and NO independent manner,as evidenced by alleviated patho⁃logical changes and up-regulated expression of TRPV4 protein in the endothelial cells from cerebral vessels.Hyp signifi⁃cantly reduced the contents of MDA,NSE,S100βand the activity of LDH in serum and decreased the fluorescence intensity of Ca2+in cerebral vascular smooth muscle cells by in vivo administration.The apoptotic rate of endothelial cells in Hyp treated group was significantly less than that in IR group.CONCLUSION Hyp does in fact ameliorate I/R injury by regulatingIP3/PKC/TRPV4 pathway.

Protective effects of Taxifolin on H_2O_2-induced damage in H9C2 cells

Background Taxifolin（Tax） is an essential natural antioxidant. Multiple studies have shown that Tax can protect cardiomyocytes from ischemia-reperfusion injury. However, the underlying mechanism is still unclear.Methods H9C2 cells were randomly divided into control, H_2O_2 group, Tax pretreatment group（Tax ＋ H_2O_2）;Tax effect group. Cell activity was detected by CCK-8 and the intracellular structure was observed by transmission electron microscopy. Autophagy was determine by Western blotting analysis of Beclin-1, Bcl-2 and PKC.Results Tax pretreatment significantly increased anti-apoptotic protein Bcl-2 and autophagy protein Beclin-1.Expression of PKC was inhibited by Tax. Conclusions Tax pretreatment could protect H9 C2 cells against H_2O_2-induced damage through the Bcl-2 and autophagy pathways.