Millet-enriched Diets Attenuate High Salt-induced Hypertension And Myocardial Damage In Male Rats

High salt diet is one of the commonest causes for hypertension and myocardial damage.The scientific research from animal studies and clinical trials has shown that the nutrition factors in millet are beneficial to lessen the risk of hypertension.The protective effect of a whole millet diet on high-salt induced hypertension has not been reported.In this study,we have evaluated the effect of nine brands of millet on high-salt induced hypertension and myocardial damage using SD male rats.We have also further investigated the possible mechanism of millet in preventing hypertension and myocardial injury induced by high salt diet at molecular level.The rats were received at seven-week-age with weight of 120 grams.Rats(12 per group)were treated with control,high salt(8%NaCl),and 9 groups of high salt plus diverse brands of millet for eight weeks.In the 8-week experimental period,the blood pressures of the rats were measured weekly by the tail cuff method while awake.The biochemical tests were conducted within 24h after the last BP measured.All of the rats were weighed,harvested myocardium was used to assay the levels of MDA,Hyp,SOD,CK and NO bioavailability.Histological changes of the myocardial tissues after weeks of control,high-salt,and high-salt plus millet treatment groups are presented.RT-PCR was used to measure the myocardial mRNA expression of AT1,AT2,JAK1,JAK2,STAT1,STAT3,TGF-?1,?-SMA,IL-6,PPAR-y,Na+/K+-ATPase and ANP.Western blot analysis was used to measure the myocardial protein expression of AT1,JAK2,STAT1,ERK1/2,p38 MAPK,JNK,P-JNK,PI3K,AKT,P-AKT,Bcl-2,Bax,I?B?,NF-?B p65 and P-NF-?B.As the result showed,the level of blood pressure significantly increased in high-salt-treated group as compared to the control group and the level of SOD,NO decreased as while MDA,Hyp and CK increased.Light microscopy of H&E stain sections showed the absence of damage of myocardial tissue of control and high-salt plus millet treatment groups,while the high-salt treated group showed significantly histological damage.The myocardial mRNA expression of ATI,JAK1,JAK2,STAT1,STAT3,TGF-(?1,?-SMA,IL-6,PPAR-y and ANP increased in high-salt-treated group,and while AT2 and Na+/K+-ATPase decreased.The myocardial protein expression of AT1,JAK2,STAT1,ERK1/2,p38 MAPK,JNK,P-JNK,Bcl-2,Bax,I?B?,and NF-?B p65 increased in high-salt-treated group,and while PI3K,P-AKT,P-NF-?B decreased.Millet treatments(MJ 16 and MJ 18)significantly attenuated the increase of blood pressure and oxidative damage;and regulated JAK-STAT,MAPKs,PI3K-AKT and NF-?B signal pathways induced by high salt.The results suggest that millet-enriched diet has significant effects on the reduction of blood pressure and myocardial injury induced by high salt in male rats.The diet with different brands of millet intake caused difference in attenuating high-salt-induced hypertension and myocardial damage in male rats.Our results support the conclusion that the anti-oxidative stress effect of millet contributes to the protection of myocardial damage caused by high salt intake.