| Objectives: Heart failure is considered as one of public health problems with important prognostic implication.However,chronic heart failure has a high mortality.Currently,many clinic studies show that inhabit the excessive secretion of neural factors,lower the level of oxidative stress and reduce inflammatory factors have already become a new target for the treatment of heart failure.Many studies have demonstrated the commonly used Chinese herbal medicine Tannic acid(TA)can reduce lipid peroxidation,inhibit apoptosis and scavenge oxygen free radicals,so we hypothesized that it may be a potential medicine for heart failure.Methods: 50 male SD rats were divided into the following five groups of 10 animals per group: control,isoproterenol(ISO),captopril(CAP),low-dose Tannic acid(L-TA)and high-dose Tannic acid(H-TA)groups.Then each rat was weighted and recorded its weights respectively.Rats of the L-TA and H-TA groups were intragastric administration(i.a.)with the dose of TA 20 mg/kg/day and 40 mg/kg/day,CAP group given a dose of 10 mg/kg/day and the control group and ISO group received an i.a.with isovolumic saline.Meanwhile rats of the latter four groups were subcutaneous injected(s.p.)with a single dose of isoproterenol 170mg/kg/day for 4 days,and the control group received an i.p.injection with isovolumic saline.On the last injection,the final body weights of each animal were recorded,and animals were anesthetized with 0.3% sodium pentobarbital.To record the Mean Arterial Blood Pressure(MABP),Left Ventricular and Diastolic Pressure(LVEDP),Left Ventricular Systolic Pressure(LVSP)and the maximum rate of change left ventricular(±dp/dt max)through the left carotid artery.Blood from each animal was collected,and the serum was separated for further analysis.The levels of B-type natriuretic peptide(BNP),endothelin-1(ET-1)and Nitric Oxide(NO)in serum were estimated by spectrophotometer using commercially available kits.The heart tissues were quickly excised and washed in ice-cold normal saline and frozen in liquid nitrogen or fixed in 4% paraformaldehyde.The activities of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px),as well as the content of malondialdehyde(MDA)in heart tissues were estimated by commercially available kits.Heart tissues were fixed with 4% paraformaldehyde,hydrated in ascending grades of ethanol,cleared with xylene and embedded in the paraffin.Tissue sections were prepared for hematoxylin and eosin(H&E).Results:1.Effects of Tannic acid on Body WeightISO-induced heart failure caused a significant decrease in weight lose,compared with the control group(P < 0.05).While,L-TA,H-TA and CAP treatment markedly enhanced the weight gain,compared with the ISO group(P < 0.05).2.Effects of Tannic acid on Histopathological Changes in HeartThe heart sections of the control group appeared healthy with normal tissue structures.By contrast,the heart sections of ISO-induced heart failure rats displayed marked histological changes.ISO group showed significant change in the number of wavy fibers,extensive necrosis,marked myocyte edema and vacuolization,which compared with those in control group.However,in L-TA,H-TA and CAP groups the histopathological changes tend to become regular.3.Effects of Tannic acid on BNP in Rat SerumCompared with the control group,the level of BNP was notably elevated in the ISO group animals(P < 0.05).However,the BNP level was clearly lower in the Tannic acid and CAP groups,compared with the ISO group(P < 0.05).4.Effects of Tannic acid on heart hemodynamicsThe Mean Arterial Blood Pressure(MABP),Left Ventricular Systolic Pressure(LVSP)and the maximum rate of change left ventricular(±dp/dtmax)in ISO group were significantly decreased compared with those in control group(P < 0.05).Meanwhile,the level of Ventricular and Diastolic Pressure(LVEDP)was increased(P < 0.05).While Treated with TA and CAP those changes were significantly to normal levels.5.Effects of Tannic acid on ET-1 and NO in Rat SerumThe level of ET-1 was remarkably elevated in the ISO group animals compared with control group(P < 0.05).The NO level was notably decreased compared with that in control group(P < 0.05).While,the ET-1 and NO levels were clearly near normal in the Tannic acid and CAP groups,compared with the ISO group(P < 0.05).6.Effects of Tannic acid on SOD,GSH-Px and MDA in heart HomogenateCompared to those of the control group,the activities of SOD and GSH-Px were dramatically decreased in the ISO group(P < 0.05),while TA and CAP treated rats showed only a slight reduced in these activities(P < 0.05).Furthermore,the MDA concentration was significantly increased in the ISO group compared with the control group(P < 0.05),while TA and CAP treatment significantly inhibited the ISO-induced excess enhancement of MDA(P < 0.05).7.Effects of Tannic acid on Apoptosis in HeartApoptosis in control and Treatment groups remained at a consistently low level,while in the ISO group was significantly increased compared with control group(P < 0.05).Tannic acid and CAP treatment groups dramatically decreased the apoptosis compared with the ISO group(P < 0.05).Conclusions: Our results indicate that Tannic acid exerted significant heart protective effects in heart failure rats,which are closely associated with the suppression of lipid peroxidation,inhibition cell apoptosis and stable the endothelial cells in the heart. |
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