Rosmarinic Acid Treatment Of Renal Interstitial Fibrosis In Rats,

Renal interstitial fibrosis (RIF) has become common basic channels and major pathology of end-stage renal disease(ESRD). In pathological conditions, tubular epithelial cells can be epithelial-mesenchymal transdifferentiation (EMT). During renal interstitial fibrosis, more than 1/3 myofibroblasts come from tubular epithelial cells, and EMT plays important role during this progress.Oxidative stress is one of the important reasons leading to cell damage, aging and death. Renal tissues require higher oxygen consumption to complete tubular reabsorption and active transport. If the generation of oxygen free radicals increases or antioxidant capacity imbalance is destoried, excessive oxygen free radicals will cause cell damage in renal tissue, leading to a variety of kidney diseases. Several pharmacotherapeutics are used for treating kidney disease, although these treatments are effective, some occasionally cause inherent and unavoidable side effects. Moreover, these pharmacotherapeutics cannot be used for long periods of time. Hence, traditional herbal medicines may improve treatment and inhibit the progression of chronic renal disease, especially in patients with weak disease activity.Rosmarinic acid (RA) is a widely distributed phenolic compound in various Labiatae herbs such as Rosmarinus officinalis (rosemary) and Perilla frutescens (perilla). RA is reported to exhibit pharmacological effects, including anti-oxidative, anti-inflammatory, anti-thrombotic, anti-bacterial, anti-mutagen and immunosuppressive effects. Recent studies have revealed that suppressive effects of RA on MsPGN and IgA nephropathy model in rats. But it is unclear whether RA on renal interstitial fibrosis is effective. In the present study, we evaluated the effects of RA on ALD induced EMT in HK-2 cells and antioxidative effects on mouse kidney with unilateral ureteral obstruction. The following two-part were studied.Objective: To explore the effects of rosmarinic acid (RA) on the tubular epithelial-mesenchymal transition and mechanisms induced by Aldosterone in vitro.Methods: HK-2 cells were cultured with Aldosterone(100nM) in the presence of different concentration of RA (5μg/ml, 25μg/ml) and mitochondrial respiratory chain complexⅠinhibitor rotenone (ROT, 10μM). Then the cultured HK-2 cells were divided into five groups: (1)normal group; (2)HK-2 cells induced by Aldosterone(ALD); (3)RA group (5μg/ml,); (4)RA group (25μg/ml); (5)rotenone group (ROT, 10μM), collected the supernatant and the cells respectively. The morphology of transdifferentiate tubular cells was observed using phase-contrast-microscopy, E-cadherin, Vimentin,α-SMA and ERK1/2 were determined by semi-quantitative RT-PCR and Western blot; Reactive oxygen species(ROS) was detected by Fluorescence Microscopic and Fluorescence Eliasa.Results: compared with control groups, HK-2 cells induced by ALD converted into spindle shape from typical epithelium shape, the expression of Vimentin mRNA,α-SMA, phosphor-ERK1/2 proteins and ROS significantly increased, the expression of E-cadherin significantly decreased; compared with ALD treated groups, RA (5μg/ml, 25μg/ml) and mitochondrial respiratory chain complexⅠinhibitor rotenone (ROT, 10μM) could inhibit ROS, vimentin,α-SMA and phosphor-ERK1/2 expression, E-cadherin mRNA expression and protein production increased.Conclusion: RA treatment could inhibit ALD-induced EMT which was activated via mitochondrial-originated, ROS-dependent ERK1/2 activation.Objective: To investigate the antioxidative effect of Rosmarinic acid on kidney of mice with unilateral ureteral obstruction (UUO).Methods: male C57BL/6J mice were randomly divided into 3 groups: Sham-operated group (n=8), UUO model group (UUO model was established by ligating the left ureter, n=24) and UUO+RA group (UUO model mice were treated with RA, n=24). The latter 2 groups were divided into subgroups according to times (3d, 7d and 14d) after intervention (n=8). Mice underwent UUO were killed at 3, 7, 14 days. The time course of injurious process in mice with UUO were examined by histopathology; Western blot of Vimentin as well as E-cadherin were measured; Malondialdehyde (MDA), superoxide dismutase (SOD) contents in the homogenized lysate of obstructive renal cortex were determined.Results: Compared with those in Sham-operated group, from 3 to 14 day, injury of renal interstitum exacerbated gradually in UUO model group, Vimentin and MDA increased significantly, E-cadherin and SOD decreased significantly. Compared with those in UUO model group, Vimentin, E-cadherin, SOD and MDA showed no significant difference in UUO+RA group on 3d; Vimentin and MDA decreased, E-cadherin and SOD increased, renal interstitial fibrosis attenuated in UUO+RA group on 7d, till 14d, these expression demonstrated significantly.Conclusion: Rosmarinic acid may attenuate renal interstitial fibrosis in mice underwent UUO by reducing lipid peroxidation production and improving antioxidative enzyme contents.