Nephroprotective effects of Aralia taibaiensis in a high-fat diet-streptozotocin rat model of diabetic nephropathy.

Diabetic nephropathy (DN) has emerged as the foremost cause of end-stage renal disease (ESRD) globally. Endoplasmic reticulum (ER) stress plays a critical role in DN progression. Triterpenoid saponin from Aralia taibaiensis (sAT) has been reported to possess anti-diabetic and anti-oxidant effects. The aim of this study was to examine the influence of sAT on DN treatment and elucidate potential underlying mechanisms. A high-fat diet (HFD) and Streptozotocin (STZ) were employed to induce DN in male Sprague Dawley (SD) rats which were subsequently treated with varying concentrations of sAT for 8 weeks. Our findings reveal that different doses of sAT significantly mitigated hyperglycemia, reduced urinary albumin excretion, and decreased plasma creatinine and blood urea nitrogen levels in DN rats. Moreover, sAT administration improved body weight, alleviated renal fibrosis and histopathological changes in the diabetic kidneys. Notably, sAT treatment partially restored increased Bax expression and decreased Bcl-2 expression. Additionally, sAT inhibited ER stress-related proteins, including GRP78, p-PERK, ATF4 and CHOP in kidneys of DN rats. These results suggest that sAT ameliorated experimental diabetic nephropathy, at least in part, through ER stress pathway. These findings provide a scientific basis for the potential development of sAT as a therapeutic agent for DN treatment.

Pharmacokinetic, Pharmacodynamic, and Safety Profiles of Proline Henagliflozin in Chinese Subjects with Varying Degrees of Liver Dysfunction.

Proline henagliflozin, a novel selective inhibitor of sodium glucose cotransporter 2, is a treatment for type 2 diabetes mellitus. We designed a parallel-group, open-label, and multicenter study to evaluate the pharmacokinetic (PK), pharmacodynamic (PD), and safety profiles of henagliflozin in Chinese subjects with varying degrees of liver dysfunction. Thirty-two subjects were enrolled and divided into four groups based on liver function (normal liver function, mild, moderate, or severe liver dysfunction). The area under the plasma concentration from time zero to infinity of henagliflozin in subjects with mild liver dysfunction, moderate liver dysfunction, and severe liver dysfunction compared with normal liver function was increased by 137%, 197%, and 204%, respectively. The maximum plasma concentration was also increased by 123%, 129%, and 139%, respectively. PK parameters of three metabolites varied to different degrees in the liver dysfunction groups than in the normal liver function group. The mean accumulative excretion amounts and fraction of dose excreted in urine expressed as a percentage were all increased with the decrease of liver function. The PD parameters were significantly higher in liver dysfunction groups than those in the normal liver function group. However, the urine creatinine (UCr) was not significantly different among the groups. No notable adverse events or adverse drug reactions were observed. Due to the higher exposures in subjects with liver dysfunction, the benefit: risk ratio should be individually assessed because the long-term safety profile and efficacy have not been specifically studied in this population.

Luteoloside inhibits Aß1-42 fibrillogenesis, disintegrates preformed fibrils, and alleviates amyloid-induced cytotoxicity.

Abnormal aggregation and fibrillogenesis of amyloid-ß protein (Aß) can cause Alzheimer's disease (AD). Thus, the discovery of effective drugs that inhibit Aß fibrillogenesis in the brain is crucial for the treatment of AD. Luteoloside, as one of the polyphenolic compounds, is found to have a certain therapeutic effect on nervous system diseases. However, it remains unknown whether luteoloside is a potential drug for treating AD by modulating Aß aggregation pathway. In this study, we performed diverse biophysical and biochemical methods to explore the inhibition of luteoloside on Aß1-42 which is linked to AD. The results demonstrated that luteoloside efficiently prevented amyloid oligomerization and cross-ß-sheet formation, reduced the rate of amyloid growth and the length of amyloid fibrils in a dose-dependent manner. Moreover, luteoloside was able to influence aggregation and conformation of Aß1-42 during different fiber-forming phases, and it could disintegrate already preformed fibrils of Aß1-42 and convert them into nontoxic aggregates. Furthermore, luteoloside protected cells from amyloid-induced cytotoxicity and hemolysis, and attenuated the level of reactive oxygen species (ROS). The molecular docking study showed that luteoloside interacted with Aß1-42 mainly via Conventional Hydrogen Bond, Carbon Hydrogen Bond, Pi-Pi T-shaped, Pi-Alkyl and Pi-Anion, thereby possibly preventing it from forming the aggregates. These observations indicate that luteoloside, a natural anti-oxidant molecule, may be applicable as an effective inhibitor of Aß, and promote further exploration of the therapeutic strategy against AD.

Cytotoxic steroidal glycosides from the rhizomes of Paris polyphylla var. yunnanensis.

Paris polyphylla var. yunnanensis (Franch.) Hand.-Mazz. (Melanthiaceae), an important specie of the genus Paris, has long been in a traditional Chinese medicine (TCM) for a long time. This study aimed to isolate and identify the structures of bioactive saponins from the rhizomes of P. polyphylla var. yunnanensis and evaluate their cytotoxicity against BxPC-3, HepG2, U373 and SGC-7901 carcinoma cell lines. Seven previously undescribed and seven known saponins were identified, and Paris saponins VII (PSVII) showed significant cytotoxicity against the BxPC-3 cell line with IC50 values of 3.59 µM. Furthermore, flow cytometry, transmission electron microscopy and western-bolt analysis revealed that PSVII inhibited the proliferation of BxPC-3 cells and might be involved in inducing apoptosis and pyroptosis by activating caspase-3, -7 and caspase-1, respectively.

Quantification of SHR0302 in human plasma by UPLC-MS/MS and application to a pharmacokinetic study.

SHR0302, as a novel Janus kinase (JAK) inhibitor 1, is used for treatment of rheumatoid arthritis (RA) in humans. A novel and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) has been developed and validated for determining the concentration of SHR0302 in human plasma. A precipitation deproteinization method was used for plasma pretreatment with methanol. Detection was carried out on an Agilent 1,260 UPLC coupled with a Triple Quad 4000 mass spectrometer operated in positive multiple reaction monitoring mode, and the analytes were separated on a Synergi Polar-RP C18 (50 × 2.0 mm, 4 µm, Phenomenex) analytical column with gradient elution of 0.1% formic acid, and 2 mmol/l ammonium acetate in water and 0.1% formic acid and 2 mmol/l ammonium acetate in methanol, The selected ion transitions were m/z 415.2 → 258.2 and m/z 398.2 → 258.2 for SHR0302 and SHR143181 (internal standard), respectively. A full validation, including selectivity, linearity, carryover, precision, accuracy, recovery, matrix effect, dilution integrity and stability, was carried out in human plasma. It was successfully applied to a pharmacokinetic study in Chinese healthy subjects after oral administration of SHR0302 tablet.

IRS-2/Akt/GSK-3ß/Nrf2 Pathway Contributes to the Protective Effects of Chikusetsu Saponin IVa against Lipotoxicity.

Chronic hyperlipidemia leads to pancreatic ß-cell apoptosis and dysfunction through inducing oxidative stress. Chikusetsu saponin IVa (CHS) showed antioxidant and antidiabetic properties in our previous studies; however, its protective effects against lipotoxicity-induced ß-cell oxidative stress and dysfunction are not clear. This study was designed to investigate the effects of CHS against lipotoxicity-induced ß-cell injuries and its possible mechanism involved. High-fat (HF) diet and a low dose of streptozotocin- (STZ-) induced type 2 diabetes mellitus (T2DM) model in vivo and ßTC3 cells subjected to 0.5 mM palmitate (PA) to imitate the lipotoxic model in vitro were performed. Pancreatic functions, ROS, and antioxidant protein measurements were performed to evaluate the effects of CHS on cell injuries. Protein expression levels were measured by Western blotting. Furthermore, siRNA-targeted Nrf2, PI3K/Akt inhibitor (LY294002), or GSK-3ß inhibitor (LiCl) was used to investigate the crosstalk relationships between proteins. As the results showed, CHS treatment inhibited apoptosis, promoted insulin release, and reduced oxidative stress. CHS treatment significantly increased the expression of Nrf2 in the cytoplasm and nuclear protein. The antioxidative and benefit effects of CHS were inhibited by siNrf2. The phosphorylation of IRS-2, PI3K, Akt, and GSK-3ß was markedly increased by CHS which were inhibited by PA. In addition, inhibition of PI3K/Akt or GSK-3ß with specific inhibitors dramatically abrogated the protective effects of CHS, revealing that the IRS-2/Akt/GSK-3ß signaling axis was involved in the protective effects of CHS. These results demonstrate that CHS protected ßTC3 cells against PA-induced oxidative stress and cell dysfunction through Nrf2 by the IRS-2/Akt/GSK-3ß-mediated pathway.

Rhein protects 5/6 nephrectomized rat against renal injury by reducing inflammation via NF-κB signaling.

BACKGROUND/AIMS: Inflammation is well known to play a pivotal role in renal injury. Rhein is a major component of the medicinal Rhubarb. The aim of this study was to investigate whether Rhein protects against renal injury and explore its underlying mechanism. METHODS: 5/6 nephrectomization (5/6 Nx) was operated on Sprague-Dawley rats. Human kidney tubular epithelial (HK-2) cells were treated with lipopolysaccharide (LPS). The level of blood urea nitrogen (BUN) and serum creatinine (SCr) was examined. Kidney tissues were stained with hematoxylin and eosin to check the morphology. The cell viability was examined. The levels of cytokines and chemokines were measured by ELISA kit. The protein expression was determined by western blot. RESULTS: Rhein significantly decreased SCr and BUN levels in 5/6 Nx rat. The morphologic findings indicated noteworthy amelioration of the damaged renal tissue in Rhein-treated rats. Rhein significantly protects HK-2 cells from LPS-mediated apoptosis. The productions of inflammatory signaling molecules (TNF-α, IL-6 and MCP-1) were inhibited by Rhein. LPS-induced NF-κB activation was also attenuated by Rhein via blocking its nuclear translocation by inhibiting phosphorylation of IκBα. CONCLUSION: These findings provide evidence that Rhein protect against renal injury, and NF-κB signaling pathway is involved in this protective effect.

Lyciumamide A, a dimer of phenolic amide, protects against NMDA-induced neurotoxicity and potential mechanisms in vitro.

Currently, the excessive activation of N-methyl-D-aspartate receptors (NMDARs) is considered to be a crucial mechanism of brain injury. Lycium barbarum A (LyA) is a dimer of phenol amides isolated from the fruit of Lycium barbarum. Our previous studies have shown that LyA has potential antioxidant activity. This study aimed to explore the neuroprotective effect of LyA and its potential mechanism. Firstly, the molecular docking was used to preliminarily explore the potential function of LyA to block NMDAR. Then, the ability of LyA was further verified by NMDA-induced human neuroblastoma SH-SY5Y cells in vivo. Treatment with LyA significantly attenuated NMDA-induced neuronal insults by increasing cell viability, reducing lactate dehydrogenase (LDH) release, and increasing cell survival. Meanwhile, LyA significantly reversed the increase in intracellular calcium and in ROS production induced by NMDA. Finally, the western blot indicated that LyA could suppress the Ca2+ influx and increase the p-NR2B, p-CaMKII, p-JNK, and p-p38 level induced by NMDA. These above findings provide evidence that LyA protect against brain injury, and restraining NMDARs and suppressing mitochondrial oxidative stress and inhibiting cell apoptosis may be involved in the protective mechanism.

PP9, a steroidal saponin, induces G2/M arrest and apoptosis in human colorectal cancer cells by inhibiting the PI3K/Akt/GSK3ß pathway.

Colorectal cancer (CRC) represents one of the commonest malignancies around the world. PP9, a natural steroidal saponin, was firstly isolated from the rhizomes of Paris polyphylla var. latifolia. However, the therapeutic effects of PP9 on CRC and the underlying molecular mechanism remain undefined. Here, we demonstrated that treatment with PP9 time- and dose-dependently inhibited HT-29 and HCT116 cells without significantly inhibiting normal NCM460 cells. Furthermore, our results indicated that PP9 effectively induced G2/M phase arrest by upregulating p21 and suppressing cdc25C, Cyclin B1 and cdc2. Meanwhile, PP9 upregulated cleaved Caspase 3, cleaved Caspase 9 and cleaved PARP and Bax, while downregulating Bcl-2 to stimulate cell apoptosis. Mechanistically, PP9-suppressed PI3K/Akt/GSK3ß signaling, while the PI3K inhibitor LY294002 augmented PP9-mediated apoptosis, G2/M arrest and effects on PI3K/Akt/GSK3ß related proteins. Finally, we showed that PP9 (10 mg/kg) significantly reduced tumor growth in nude mouse CRC xenografts, more potently than 5-Fu (20 mg/kg). Jointly, these data firstly demonstrated that PP9 promotes G2/M arrest and apoptotic death in CRC cells through PI3K/Akt/GSK3ß signaling suppression, suggesting that PP9 could be considered a new and promising candidate for CRC therapy.

Renal protection of rhein against 5/6 nephrectomied-induced chronic kidney disease: role of SIRT3-FOXO3α signalling pathway.

OBJECTIVES: The purpose of this study is to investigate the antifibrosis and anti-oxidation of rhein in vivo and in vitro, and to evaluate potential mechanisms involved in the treatment of chronic kidney disease (CKD). METHODS: In experimental animal studies, CKD was established by 5/6 nephrectomy (5/6Nx). Serum creatinine (Scr) and blood urea nitrogen (BUN) were determined. Histopathologic tests were performed by HE and Masson trichrome stained. The level of ROS was investigated by fluorescence microplate with the probe 2', 7'-dichlorofluorescein diacetate (DCFH-DA). The protein expressions of p47phox and gp91phox were measured in 5/6Nx rats. In HK-2 cells, the expression of SIRT3 and Foxo3α was measured in SIRT3 knockdown conditions. The indicators of oxidation and fibrosisi were measured in SIRT3 knockdown conditions. KEY FINDINGS: The results showed that, in addition to reducing renal interstitial pathologic injury and collagen fibrils, rhein administration improved renal function. The protective mechanisms were attributed to active SIRT3/FOXO3α signalling pathway and then play the anti-oxidative capacity of rhein, as well as to subsequent antifibrotic effect. CONCLUSION: Taken together, rhein protected kidney through SIRT3/FOXO3a involvement. The anti-oxidative capacity of rhein contributed to the protective effects including the subsequent antifibrotic responses.

A phenolic amide (LyA) isolated from the fruits of Lycium barbarum protects against cerebral ischemia-reperfusion injury via PKCε/Nrf2/HO-1 pathway.

Lyciumamide A (LyA), a dimer of phenolic amide isolated from the fruits of Lycium barbarum, has been confirmed to possess potent antioxidant activity. This study was aimed to investigate the neuroprotection and molecular mechanisms of LyA against cerebral ischemia/reperfusion (I/R) injury via improving antioxidant activity. The model of middle cerebral artery occlusion (MCAO) and SH-SY5Y cells induced by oxygen and glucose deprivation (OGD) were adopted to verify the neuroprotective effects and the potential pharmacology mechanisms of LyA in vivo and in vitro. In MCAO model, treatment with LyA significantly improved neurologic score, reduced infarct volume, and relieved oxidative stress injury at 48 h after reperfusion. Meanwhile, LyA markedly increased the transcription Nrf2 and HO-1 expressions in the ischemic cerebral cortex. In vitro results showed that LyA protected differentiated SH-SY5Y cells against OGD-induced injury. LyA significantly decreased the expression of caspase-3 and the Bax/Bcl-2 ratio. But knockdown of Nrf2 or HO-1 attenuated the protective effect of LyA. Similarly, knockdown of protein kinase Cε (PKCε) inhibited LyA-induced Nrf2/HO-1 activation, and abated its protective effects. In conclusion, this study firstly demonstrated that LyA protects against cerebral I/R injury, ameliorates oxidative damage and neuronal apoptosis, partly via activation of PKCε/Nrf2/HO-1 pathway.

Development of a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for simultaneous determination of epigallocatechin-3-gallate, silibinin, and curcumin in plasma and different tissues after oral dosing of Protandim in rats and its application in pharmacokinetic and tissue distribution studies.

Protandim is an over-the-counter herbal dietary supplement. The key components of Protandim, i.e., epigallocatechin-3-gallate (EGCG), silibinin (SIL), and curcumin (CUR) were simultaneously analyzed through a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method in plasma and different tissues after administration of Protandim in rats. The developed and validated method was employed to assess the pharmacokinetic profiles and the accumulation of EGCG, SIL, CUR in rat plasma and tissue homogenates. The plasma and tissue homogenates were subjected to liquid-liquid extraction and separated on a Hypurity C18 column (50 × 4.6 mm) with a gradient elution of water and acetonitrile. Mass spectrometric detection was performed in the multiple reaction monitoring mode (MRM) following the transitions: m/z 457.3/169.3, m/z 481.3/125.0, m/z 367.3/149.3 and m/z 609.4 /300.2 for EGCG, SIL, CUR, and RU (rutin), respectively. The concentrations of all the analytes in the range from 2 to 1000 ng/mL showed linear relationships with respective peak areas in different matrices. For all matrices, the values of inter-day and intra-day precisions and accuracies were less than 10.3% of the nominal concentration. The matrix effect, extraction recovery, dilution integrity, and stability values were all within acceptable levels. This method was successfully applied for determining the pharmacokinetics and tissue distribution of the components in rats after the intragastrical administration of a single-dose (364.5 mg/kg) or multiple-doses (1458 mg/kg) of Protandim. The data showed that EGCG, SIL, and CUR did not accumulate in rats after multiple doses of Protandim, and the three main components were distributed mainly in the small intestine.

Salvianolic acid A ameliorates renal ischemia/reperfusion injury by activating Akt/mTOR/4EBP1 signaling pathway.

Salvianolic acid A (Sal A) has been shown to prevent and treat ischemic cardiovascular, as well as cerebral vascular diseases. However, little is known about Sal A in renal ischemia/reperfusion (I/R) injury. In this study, a renal I/R injury model in rats and a hypoxia/reoxygenation (H/R) model to damage proximal renal tubular cells (HK-2) were used to assess whether Sal A halts the development and progression of renal I/R injury. As compared with vehicle treatment, Sal A significantly attenuated kidney injury after renal I/R injury, accompanied by decreases in plasma creatinine, blood urea nitrogen levels, the number of apoptosis-positive tubular cells, and kidney oxidative stress. Sal A also activated phosphorylated protein kinase B (p-Akt) and phosphorylated-mammalian target of rapamycin (p-mTOR) compared with vehicle-treated I/R injury rats. In H/R-injured HK-2 cells, Sal A can reduce the levels of reactive oxygen species in a dose-related manner. Similar to the results from in vivo experiments, in vitro Sal A also increased the protein expression of phosphorylated-eukaryotic initiation factor 4E binding protein 1 (p-4EBP1) compared with vehicle. Furthermore, the cytoprotective activity of Sal A was inhibited by LY294002 and rapamycin. These findings indicate that Sal A can ameliorate renal I/R injury and promote tubular cell survival partly via the Akt/mTOR/4EBP1pathway. Sal A could be a candidate compound to prevent ischemic tissue damage.

Brazilin exerts protective effects against renal ischemia-reperfusion injury by inhibiting the NF-κB signaling pathway.

Renal ischemia-reperfusion (I/R) injury is associated with high morbidity and mortality as there is currently no available effective therapeutic strategy with which to treat this injury. Thus, the aim of this study was to investigate the potential protective effects of brazilin, a major active component of the Chinese medicine Caesalpinia sappan L., against renal I/R injury in vitro and in vivo. Rats were subjected to removal of the right kidney and I/R injury to the left kidney (ischemia for 45 min followed by reperfusion for 24 h). Treatment with brazilin (30 mg/kg, administered intravenously at 30 min prior to ischemia) led to the reversal of I/R-induced changes in serum creatinine (Scr) and blood urea nitrogen (BUN) levels, and also attenuated the histopathological damage induced by I/R. Furthermore, TUNEL assay revealed that brazilin reduced cell necrosis, and significantly decreased the expression of tumor necrosis factor (TNF)-α and interleukin (IL)-1ß in renal tissue. Moreover, HK-2 cells were used in order to elucidate the mechanisms responsible for the protective effects of brazilin. The levels of phosphorylated IκBα and the nuclear translocation of nuclear factor-κB (NF-κB) were all evidently decreased by brazilin. These findings suggested that pre-treatment with brazilin protects against I/R-induced renal damage and suppresses the inflammatory response by inhibiting the activation of the NF-κB signaling pathway.

miR-592/WSB1/HIF-1α axis inhibits glycolytic metabolism to decrease hepatocellular carcinoma growth.

Hepatocellular carcinoma (HCC) cells rapidly switch their energy source from oxidative phosphorylation to glycolytic metabolism in order to efficiently proliferate. However, the molecular mechanisms responsible for this switch remain unclear. In this study, we found that miR-592 was frequently downregulated in human HCC tissues and cell lines, and its downregulation was closely correlated with aggressive clinicopathological features and poor prognosis of HCC patients. Overexpression of miR-592 inhibited aerobic glycolysis and proliferation in HCC cells in vitro. Conversely, knockdown of miR-592 promoted HCC growth in both subcutaneous injection and orthotopic liver tumor implantation models in vivo. Mechanistically, miR-592 downregulation in human HCCs was correlated with an upregulation of WD repeat and SOCS box containing 1 (WSB1). We further showed that miR-592 directly binds to the 3'-UTR of the WSB1 gene, thus disrupting hypoxia inducible factor-1α (HIF-1α) protein stabilization. In turn, overexpression of WSB1 in HCC cells rescued decreased HIF-1α expression, glucose uptake, and HCC growth induced by miR-592. Collectively, our clinical data and functional studies suggest that miR-592 is a new robust inhibitor of the Warburg effect and a promising therapeutic target for HCC treatment.

Hydroxysafflor Yellow A Ameliorates Renal Fibrosis by Suppressing TGF-ß1-Induced Epithelial-to-Mesenchymal Transition.

OBJECTIVE: Renal fibrosis is the common pathological foundation of many chronic kidney diseases (CKDs). The aim of this study was to investigate whether Hydroxysafflor yellow A (HSYA) can preserve renal function by inhibiting the progression of renal fibrosis and the potential mechanisms. METHODS: Renal fibrosis was induced by unilateral ureteral obstruction (UUO) performed on 7-week-old C57BL/6 mice. HSYA (10, 50 and 100 mg/kg) were intragastrically administered. Sham group and model group were administered with the same volume of vehicle. Serum and kidney samples were collected 14 days after the UUO surgery. Serum biochemical indicators were measured by automatic biochemical analyzer. Histological changes were evaluated by HE and Masson staining. In vitro, the anti-fibrotic effect of HSYA was tested on human recombinant transforming growth factor-ß1 (TGF-ß1) stimulated HK-2 cells. The protein levels of α-SMA, collagen-I and fibronectin in kidney tissue and HK-2 cells were measured by immunohistochemistry and immunofluorescence. The protein levels of apoptosis-relative and TGF-ß1/Smad3 signaling were detected by western blot. RESULTS: HSYA slowed the development of renal fibrosis both in vivo and in vitro. In UUO rats, renal function index suggested that HSYA treatment decreased the level of serum creatinine (Scr) and blood urea nitrogen (BUN) rose by UUO (P<0.05). HE staining and Masson staining demonstrated that kidney interstitial fibrosis, tubular atrophy, and inflammatory cell infiltration were notably attenuated in the high-dose HSYA group compared with the model group. The expressions of α-SMA, collagen-I and fibronectin were decreased in the UUO kidney and HK-2 cells of the HSYA-treatment group. Moreover, HSYA reduced the apoptotic rate of HK-2 cells stimulated by TGF-ß1. Further study revealed that HSYA regulated the TGF-ß1/Smads signaling pathway both in kidney tissue and HK-2 cells. CONCLUSIONS: These results suggested that HSYA had a protective effect against fibrosis in renal cells, at least partly, through inhibiting TGF-ß1/smad3-mediated Epithelial-mesenchymal transition signaling pathway.

Shen-Kang protects 5/6 nephrectomized rats against renal injury by reducing oxidative stress through the MAPK signaling pathways.

Chronic kidney disease (CKD) is a worldwide public health concern with limited treatment options. The incidence of CDK is increasing and the disease is associated with a poor quality of life and a high financial cost of treatment. Shen-Kang (SK), a traditional Chinese herbal medicine, has been used clinically in the treatment of renal diseases for decades. This study was carried out to validate the therapeutic effects of SK on renal injury induced by 5/6 nephrectomy, as well as its effects on the apoptosis of proximal tubule epithelial cells (HK-2 cells), in an aim to elucidate its mechanisms of action. For this purpose, an animal model of renal injury was created by subjecting rats to a 5/6 nephrectomy. The rats in the sham-operated and model groups received distilled water, while the rats in the SK and enalapril (EN) groups were treated with SK or EN. The levels of blood urea nitrogen (BUN) and serum creatinine (SCr) were measured. Kidney tissues obtained from the rats were stained with hematoxylin and eosin. HK-2 cells were employed to investigate the effects of SK on the apoptosis of renal proximal tubule epithelial cells induced by treatment with hydrogen peroxide (H2O2). In addition, cell viability was measured by MTT assay. Apoptotic events were monitored by western blot analysis, flow cytometric analysis and nuclear morphological anlaysis. The levels of intracellular reactive oxygen species (ROS) were measured by flow cytometric analysis with dihydroethidium staining. The results revealed that the administration of SK to 5/6 nephrectomized rats for 1 week significantly decreased the levels of SCr and BUN. The morphological observations of the kidneys also indicated the amelioration of damage to renal tissue. Treatment of the HK-2 cells with SK significantly protected the cells from H2O2-induced apoptosis, as indicated by an increase in cell viability, the decrease in the cleavage of poly(ADP-ribose) polymerase (PARP) and fewer condensed nuclei. H2O2-induced ROS production was also attenuated by treatment with SK. Of note, the increase in the levels of phosphorylated extracellular signal-regulated kinase (ERK) and phosphorylated p38 which occurred in response to exposure to H2O2 was inhibited by treatment with SK. No changes were observed in the levels of phosphorylated JNK under the same treatment conditions. Thus, the mitogen-activated protein kinase (MAPK) signaling pathways play an essential role in the development of CKD. SK alleviated renal injury in rats induced by 5/6 nephrectomy and prevented the H2O2-induced apoptosis of HK-2 cells through the MAPK signaling pathways.

ShenKang injection suppresses kidney fibrosis and oxidative stress via transforming growth factor-ß/Smad3 signalling pathway in vivo and in vitro.

OBJECTIVES: The purpose of this study is to investigate the antifibrosis and antioxidation of ShenKang injection (SKI) in vivo and in vitro and to evaluate potential mechanisms involved in the treatment of chronic kidney disease (CKD). METHODS: In experimental animal studies, CKD was established by 5/6 nephrectomy (5/6Nx). Serum creatinine (Scr) and blood urea nitrogen (BUN) were determined. Histopathological tests were performed by H&E and Masson trichrome stained. The protein expressions of fibronectin (FN), collagen Ι, α-smooth muscle actin (α-SMA) and transforming growth factor-ß (TGF-ß) and phosphorylation of Smad3 were measured in 5/6Nx rats. In Human kidney proximal tubular cell line (HK-2) cells, the effects of TGF-ß/Smad3 signalling pathway on renal fibrosis and oxidative injury were examined. KEY FINDINGS: 5/6Nx induced severe renal damages. Treatment of rats with SKI markedly reduced levels of Scr and BUN, alleviated expression of fibrosis-associated signalling molecules and reduced expression of TGF-ß and phosphorylated Smad3. Meanwhile, in HK-2 cells, after exposure to TGF-ß and H2 O2 , the protein expression of renal fibrosis was significantly increased. The generation of oxidative stress was also elevated. The severity of fibrosis and oxidative damage appears to be reduced after treatment with SKI. CONCLUSION: SKI inhibits renal fibrosis and oxidative stress through downregulation of TGF-ß/Smad3 signalling pathway.

Protective effects of Lycium barbarum polysaccharide on 6-OHDA-induced apoptosis in PC12 cells through the ROS-NO pathway.

Oxidative stress plays an important role in Parkinson's disease and other neurodegenerative disorders. Lycium barbarum polysaccharides (LBP), the main active ingredients extracted from the fruits of Lycium barbarum L., have been shown to be a potent antioxidant. In the present study, we investigated the protective effects, and the possible mechanism of action of LBP against 6-hydroxydopamine (6-OHDA)-induced apoptosis in PC12 cells. Our data demonstrated that LBP significantly reversed the 6-OHDA-induced decrease in cell viability, prevented 6-OHDA-induced changes in condensed nuclei and decreased the percentage of apoptotic cells in a dose-dependent manner. Furthermore, LBP also slowed the accumulation of reactive oxygen species (ROS) and nitric oxide (NO), decreased the level of protein-bound 3-nitrotyrosine (3-NT) and intracellular free Ca2+, and inhibiting the overexpression of nuclear factor κB (NF-κB), neuronal nitric oxide synthase (nNOS) and inducible nitric oxide synthase (iNOS). These results demonstrate that LBP prevents 6-OHDA-induced apoptosis in PC12 cells, at least in part through the ROS-NO pathway.

High performance liquid chromatographic method for the determination of cinepazide maleate and its application to a pharmacokinetic study in rats.

A simple and reliable high performance liquid chromatographic (HPLC) method has been developed and validated to quantify cinepazide maleate, a calcium blocker, in rat plasma. Cinepazide maleate and Tinidazole (internal standard) have been extracted by a simple liquid-liquid extraction before injection into chromatographic system. Chromatographic separation was achieved on a reversed phase C18 column with a mobile phase consisted of a water mixture of 10mM potassium dihydrogen phosphate (pH=4.5):methanol (40:60, v/v), pumped at flow rate of 1.0mL/min, and detected at 303nm. The method exhibited a linear range of 0.12-120µg/mL in blank rat plasma, with the lower detection limit of 0.06µg/mL. The method was statistically validated for linearity, accuracy, precision, selectivity and stability following FDA guidelines. The intra- and inter-assay coefficients of variation did not exceed ±15% from the nominal concentration. The accuracy of cinepazide maleate was within ±15% of the theoretical value. The assay has been applied successfully in a pharmacokinetic study of cinepazide maleate after a single intravenous at three doses in rat. And cinepazide maleate injection can improve the bioavailability of cinepazide maleate greatly, and has a dose-dependence profile in rats.