Effect and mechanism of pachymic acid on renal function and fibrosis in rats with chronic renal failure / 中国药房

ABSTRACT

OBJECTIVE To investigate the effect of pachymic acid （PA） on renal function and fibrosis in chronic renal failure （CRF） rats and its potential mechanism based on the Ras homolog gene family member A （RhoA）/Rho-associated coiled-coil forming protein kinase （ROCK） signaling pathway. METHODS Using male SD rats as subjects， the CRF model was established by 5/6 nephrectomy； the successfully modeled rats were divided into model group， PA low-dose， medium-dose and high-dose groups （5， 10， 20 mg/kg PA）， high-dose PA+ROCK pathway activator lysophosphatidic acid （LPA） group （20 mg/kg PA+1 mg/kg LPA）， with 15 rats in each group. Another 15 rats were selected as the sham operation group with only the kidney exposed but not excised. The rats in each drug group were gavaged and/or injected with the corresponding liquid via the caudal vein， once a day， for 12 consecutive weeks. During the experiment， the general condition of rats was observed in each group. After the last administration， the serum renal function indexes （blood urea nitrogen， serum creatinine， uric acid） of rats in each group were detected， the renal histopathological changes were observed； the renal tubule injury score and the area of renal fibrosis were quantified. The levels of oxidative stress indexes [malondialdehyde （MDA）， superoxide dismutase （SOD）] and inflammatory factors （tumor necrosis factor-α， interleukin-1β， interleukin-6）， the positive expression rates of connective tissue growth factor （CTGF） and collagen Ⅰ were detected as well as the expression levels of pathway-related proteins （RhoA， ROCK1） and fibrosis- related proteins （transforming growth factor-β1， bare corneum homologs 2， α-smooth muscle actin） were determined. RESULTS Compared with the sham operation group， the rats in model group had reduced diet， smaller body size， listless spirit and sluggish response， reduced and atrophied glomeruli， dilated renal tubules with chaotic structure， and a large number of inflammatory cells infiltrated interstitium； the serum levels of renal function indexes， renal tubule injury score， renal fibrosis area proportion， the levels of MDA and inflammatory factors， the positive expression rates of CTGF and collagen Ⅰ， and the expression levels of pathway-related proteins and fibrosis-related proteins in renal tissues were significantly increased， while SOD level was significantly decreased （P＜0.05）. Compared with the model group， the general condition and pathological injuries of kidney tissue of rats in PA groups were improved to varying degrees，and the above quantitative indexes were significantly improved in a dose-dependent manner （P＜0.05）. LPA could significantly reverse the improvement effect of PA on the above indicators （P＜0.05）. CONCLUSIONS PA can improve renal function and alleviate renal fibrosis in CRF rats， which may be related to inhibiting the activation of RhoA/ROCK signaling pathway.