ABSTRACT
The aim of this paper was to study the effect of total flavones of Clematis filamentosa Dunn(TFCD) post-conditioning against myocardial ischemia-reperfusion injury (MIRI) and the role of PI3K/Akt-eNOS signaling pathway. Forty male SD rats were divided randomly into five groups: Sham group, model group (I/R), TFCD post-conditioning group (TFCD), TFCD post-condition-ing+LY294002 (a PI3K/Akt signaling pathway inhibitor) group (TFCD+LY), and LY294002 group (LY). At the end of reperfusion, hemodynamic parameters were recorded, morphology changes of myocardial tissue were evaluated by using HE staining, and myocardial infarct size were observed, blood samples were obtained to determine plasma activation of lactate dehydrogenase (LDH), creatine kinase (CK) nitric oxide (NO), endothelial nitric oxide synthase (eNOS), superoxide dismutase (SOD), maleic dialdehyde (MDA) and glutathione peroxidase (GSH-Px). The expressions of Akt, p-Akt, eNOS and p-eNOS proteins were assessed by using Western blot, and eNOS and inducible nitric oxide synthase (iNOS) mRNA was measured by RT-PCR. The results showed that, compared with the model group, TFCD post-conditioning remarkably improved hemodynamics function and myocardial structure, reduced myocardial infarct size and enhanced the contents of NO, eNOS, SOD and GSH-Px, and decreased the contents of LDH, CK and MDA, increased the levels of phosphorylation of Akt and eNOS protein expression, eNOS and iNOS mRNA expression significantly(P＜0.05 or P＜0.01). These effects were inhibited by LY294002, a blocker of PI3K/Akt signaling pathway. The above experiments indicated that TFCD post-conditioning could significantly reduce MIRI in rats, the mechanism of which may be associated with increasing antioxidation, scavenging oxygen free radicals, regulating NO generation and activating PI3K/Akt-eNOS signaling pathway.
Subject(s)
Animals , Male , Rats , Clematis , Flavones , Myocardial Reperfusion Injury , Nitric Oxide Synthase Type III , Phosphatidylinositol 3-Kinases , Proto-Oncogene Proteins c-akt , Rats, Sprague-Dawley , Signal TransductionABSTRACT
<p><b>OBJECTIVE</b>To investigate the antipyretic mechanism of Herba Ephedrae (Eph)-Ramulus Cinnamomi (RC) herb pair on yeast-induced pyrexia in rats.</p><p><b>METHODS</b>Totally 30 qualified male SD rats were randomly assigned to the normal control (NC) group, the pyrexia model (model) group, the Eph, RC and Eph-RC treatment groups by a random digital table, 6 rats in each group. Each rat received a 20% aqueous suspension of yeast (10 mL/kg) except the NC group. The 3 treatment groups were administered 8.1, 5.4 and 13.5 g/kg Eph, RC and Eph-RC respectively at 5 and 12 h after yeast injection, the NC group and the model groups were administered equal volume of distilled water. Rectal temperatures were measured at 0, 6, 8, 10, 12, 15, 18, 24 and 30 h and urine was collected prior to yeast injection and at 6, 10, 18, 24, 30, and 36 h after yeast injection. Then urine metabolomic profiling by gas chromatography tandem mass spectrometry, coupled with multivariate statistical analysis and pattern recognition techniques were used to explore the antipyretic effects of Eph-RC. Partial least squares discriminate analysis was used to analyze the metabolomics dataset including classification and regression in metabolomics plot profiling.</p><p><b>RESULTS</b>Compared with the NC group, rectal temperatures were significantly higher in the model group (P<0.01), while 3 treatment groups decreased significantly compared with the model group (P<0.05 or P<0.01). Rectal temperatures of Eph-RC-treated rats started to go down at 6 h, and markedly decreased at 8, 12, 15, 18 and 24 h (P<0.05 or P<0.01), while those of the Eph and RC groups had decreased firstly at 8 h and were markedly lower at 12 h (P<0.05 or P<0.01). Seventeen potential biomarkers related to pyrexia were confirmed and identified, including pyruvic acid, L-phenylalanine, L-tyrosine, phenylacetic acid, hippuric acid, succinic acid, citrate and so on. Eight potential alterations of metabolic pathways including phenylalanine metabolism, citrate cycle, tryptophan metabolism, biosynthesis of valine, leucine and isoleucine, were identified in relation to the antipyretic effects of Eph-RC using MetPA software.</p><p><b>CONCLUSION</b>The antipyretic effect of Eph-RC herb pair on yeast-induced pyrexia in rats involved correction of perturbed amino acid, fatty acid, and carbohydrate metabolism according to the metabolic pathway analysis with MetPA.</p>