Grape Seeed Proanthocyanidins Prevents DOCA-salt Hypertension Induced Renal Injury And Its Mechanisms In Rats

1 Objective Kidneys play a vital role in blood pressure regulation, but it is also one of the major target organ in hypertension. The number of patients with kidney damage due to hypertension was increasing in recent years. Therefore, the study of kidney damage caused by hypertension, to protect the kidneys as well as control of hypertension have great significance. Grape seed proanthocyanidins(GSP) has been reported to be potent anti-oxidants and possess property as free radical scavengers. The present study was to investigate prevention of GSP on renal injury in DOCA-salt hypertensive rats and explore molecular mechanisms underlying its protective effects.2 Methods Unilateral kidney removal, subcutaneous DOCA, while giving high-salt diet can replicate DOCA- high-salt hypertensive models quickly. SD rats, weight 180-200 g, a total of 54 rats were randomly divided into seven groups: Sham group, Un X-sham group, DOCA-salt hypertension group, GSP 150 group, GSP 240 group, GSP 384 group, ALM group. In addition to the Sham group, the remaining rats were removed left kidney and subcutaneous injection of DOCA 120 mg·kg-1·wk-1 at three days later,while drinking with high saline 0.2% KCl and 1% Na Cl sustained for four weeks. Each treatment group were treated with different concentrations of GSP or ALM gavage once daily for four weeks. We given equal volume of ultrapure water to control group and the model group. We collect the urine of rats once a week for four weeks, urinary protein concentration was measured by the BCA method. After four weeks,intraperitoneal injection of anesthesia, collect the whole blood in the abdominal aorta,and quickly remove the right kidney, recorded kidney weight and calculated kidney weight index. HE staining and VG staining were observed pathological changes and fibrosis of the kidney. Double antibody ABC-ELISA assay serum creatinine(Scr) and blood urea nitrogen(BUN) contents. Colorimetric detected serum uric acid(UA),superoxide dismutase(SOD) activity and malondialdehyde(MDA) content of kidney tissue. Alkaline hydrolysis detected hydroxyproline(Hyp) content of kidney tissue.Western blot determine JNK and p38 protein expression and phosphorylation levels in kidney tissue.3 Results Sham group and Un X-Sham group, the difference have no statistically significant.After subcutaneous injection DOCA and given high salt water rats for four weeks.Compared with the control group, kidney weight and kidney weight index of rats in the model group increased significantly(P<0.01). After giving GSP and ALM treated rats.Kidney weight and kidney weight index of GSP groups and ALM group were significantly reduced. HE staining showed significantly increased glomerular area model group(P<0.01). After giving GSP and ALM experimental treatment, the glomerular area of GSP groups and ALM group were significantly reduced(P<0.01).kidney collagen volume fraction(CVF) and hydroxyproline(Hyp) content of model group was increased, the difference have statistically significant(P<0.01,P<0.05). Compared with the model group, the collagen fibers accumulation arrangement of GSP groups and ALM group tends to rule. CVF and Hyp content of kidney tissue is reduced, the difference was statistically significant(P<0.01, P<0.05).After three weeks, the urine protein content of DOCA-salt group have appeared significantly increased(P<0.05). Compared with the DOCA-salt hypertensive rats, the urine protein of GSP240 group, GSP384 group and ALM group were significantly decreased(P<0.05, P<0.01). Compared with the control group, the serum BUN and Scr content of DOCA high-salt hypertensive rat increased, but the difference wasn’t statistically significant. The serum UA content of model group was increased, but the difference wasn’t statistically significant. The serum BUN and Scr contents of GSP groups and ALM group didn’t appear significantly reduced, the difference wasn’t statistically significant. The serum UA content was reduced, but the difference wasn’t statistically significant.Compared with Unx-sham, SOD content was decreased significantly, and MDA content was significantly increased in DOCA-salt group, the difference was statistically significant(P<0.01). After different doses GSP and ALM experimental treatment for 4 weeks, inhibited the kidney tissue SOD content decreased and MDA increased significantly(P<0.01). The expression of p-p38 was significantly increased in DOCA-salt group(P<0.01). After four weeks of treatment, GSP240 group and GSP384 group could inhibit p-p38 high expression(P<0.05). The highly expressed of p-p38 was suppressed in GSP150 group and ALM group, but the difference wasn’t statistically significant. Compared with Unx-sham, p-JNK expression increased in model group,but the difference wasn’t statistically significant. After 4 weeks, p-JNK expression was inhibited in GSP groups and ALM group, but the difference wasn’t statistically significant.4 Conclusion GSP can significantly improve kidney remodeling induced by DOCA high-salt,which may be related with ROS-p-38/JNK signaling pathway, reducing oxidative stress levels and improve renal dysfunction.