Effects Of Total Flavones Of Buckwheat Flowers And Leaves (TFBFL) On Type2Diabetic Rats Myocardial Injury And PI3K

Objective To investigate the protective effects of total flavonoids of buckwheat flowersand leaves (TFBFL) on myocardial injury in T2DM diabetic rats and explore its possiblemechanisms.Methods Male SD rats of clean grade were randomly divided into control group andmodel group. Control group rats were fed with normal diet, model group rats were fedwith high-sucrose-fat diet. After16weeks and fasting for12h, the rats with high-sucrose-fat diet feed were injected,by tail vein, lower-dosage streptozotocin (STZ)(12.5mg/kg,every72h, three times in a row) to set up type2diabetic rats model. After one week,2-hour postprandial blood glucose was measured by taking tail venous blood. The valuehigher than11.1mmol/L three times in a row was considered as an index successfullydiabetic model. Forty successful model rats were randomly divided into model group,MET (0.15g/kg/d) group, L-TFBFL (0.1g/kg/d) group and H-TFBFL (0.2g/kg/d) group.All the rats were administered by lavage once a day, for six consecutive weeks, the samevolume of saline was administered to Control and Model groups. During administration,we observed the general state of the rats dynamically; assessed2hPBG at0,2,4,6weeks;fasting12h after administration, glucose tolerance, LDH, CK-MB, BW and HWI weremeasureed; took the apex and left ventricular tissue and observed morphologic changesof myocardium by HE, Masson staining and electron microscopy; took right ventriculartissue and assessed PI3K expression by immunohistochemistry and western blot.Results1Compared with control group, model group rats polydipsia, polyphagia,polyuria, weight gained, the consciousness was apathetic, the reaction was dull. Theabove general situation of drug-treated rats improved, weight decreased, but there was nodifference between TFBFL and Model groups (P>0.05).2Glucose tolerance resultsshow: Blood glucose level of Model group is higher than that of Control group; comparedwith Model group, blood glucose level of treatment groups significantly decreased(P<0.01), TFBFL could improve abnormal glucose tolerance in a dose-dependent manner.3Before administration,2h PBG of establishing-model groups was higher than Controlgroup, for2h PBG, there was no differences between establishing-model groups(P>0.05). After treatment,2h PBG of each treatment group was significantly lower than Model group (P<0.01), lowering effect of4WPBG and6WPBG is more pronounced, theeffect of H-TFBFL group was more obvious and was similar to MET group (P>0.05).4Compared with the control group, the serum CK-MB activity of model group wassignificantly increased (P<0.05); after treatment with TFBFL, the CK-MB level wasmarkedly reduced (P <0.05); there was no significant difference in medium LDH activitybetween groups.5Weight of model group increased significantly than control group(P<0.01), after TFBFL treatment, weight reduced but there was no significant difference(P>0.05), there was no difference in HWI between five groups (P>0.05).6The results ofHE and Masson staining showed: Myocardial cells of model group were swollen andhypertrophy obviously, myocardial fibers arranged irregularly; HE staining showed,intercellular fibroblast proliferation on myocardium, inflammatory cell infiltration,marked hyperemia; Masson staining showed myocardial interstitial collagen deposition;The treatment group improved myocardial fibers disorders, myocardial cell swelling wasmitigated, myocardial collagen and fibroblast were decreased.7The results of electronmicroscope: myocardial tissue of the diabetic rats showed disordered sarcomere,increased number of mitochondria in myocardial cells, disorganized, extruded, andmitochondria swelling, vacuolization, cristae sparse; compared with the model group, thetreatment groups had obvious improvement on myocardial tissue structure, H-TFBFLand MET groups improved more obviously.8PI3K tests showed: Compared withControl group, PI3K expression in model group decreased significantly (P<0.01), andcompared with Model group, in treatment groups, PI3K was significantly increased(P<0.01), PI3K of H-TFBFL group was significantly higher than that of MET group(P<0.01).Conclusion TFBFL has protective effects on myocardial injury in type2diabetic rats,and the mechanism may be related to the improvement of glucose metabolism and increasethe expression of PI3K, but the exact mechanism remains to be further studied.