Effects of salvianolic acid-A on NIH/3T3 fibroblast proliferation, collagen synthesis and gene expression

Design, synthesis, and evaluation of pirfenidone-NSAIDs conjugates for the treatment of idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a fatal, chronic and progressive lung disease that threaten public health like many cancers. In this study, targeting the significant driving factor, inflammatory response, of the IPF, several conjugates of pirfenidone (PFD) with non-steroidal anti-inflammatory drugs (NSAIDs), along with their derivatives, were designed and synthesized to enhance the anti-IPF potency of PFD. Among these compounds, the (S)-ibuprofen-PFD conjugate 5b exhibited the most potent anti-proliferation activity against NIH3T3 cells, demonstrating up to a 343-fold improvement compared to PFD (IC50 = 0.04 mM vs IC50 = 13.72 mM). Notably, 5b exhibited superior activity in inhibiting the migration of macrophages induced by TGF-β compared to PFD. Additionally, 5b demonstrated significant suppression of TGF-β-induced migration of NIH3T3 cells and induction of apoptosis in NIH3T3 cells. Mechanistic studies revealed that 5b reduced the expression of collagen I and α-SMA by inhibiting the TGF-β/SMAD3 pathway. In a bleomycin-induced pulmonary fibrosis model, treatment with 5b (40 mg/kg/day, orally) exhibited a more pronounced effect on reducing the degree of histopathological changes in lung tissue and alleviating collagen deposition compared to PFD (100 mg/kg/day, orally). Moreover, 5b could block the expression of collagen I, α-SMA, fibronectin, and pro-inflammatory factors (IL-6, IFN-γ, and TNF-α) compared to PFD, while demonstrating low toxicity in vivo. These preliminary results indicated that the hybridization of PFD with NSAIDs represented an effective modification approach to improve the anti-IPF potency of PFD. Consequently, 5b emerged as a promising candidate for the further development of new anti-IPF agents.

Resveratrol inhibits hepatic stellate cell activation by regulating autophagy and apoptosis through the SIRT1 and JNK signaling pathways

Resveratrol, which is a natural polyphenol found in grapes, berries, peanuts, and medicinal plants, has previously been reported to perform several biological functions, including inhibition of hepatic fibrosis. Activated hepatic stellate cells (HSCs) are the major cellular source of matrix protein-secreting myofibroblasts, which are the major drivers of liver fibrogenesis. Numerous studies on the protective effects of resveratrol against liver fibrosis have focused on the inhibition of HSC activation. Although the underlying mechanisms remain to be fully elucidated, the regulation of autophagy and apoptosis might be intimately related. The mouse HSC line JS1 was stimulated with resveratrol to assess the mechanism and relationship between autophagy and apoptosis. Resveratrol modulated JS1 cell viability in a dose-dependent manner. Moreover, resveratrol inhibited JS1 cell activation and induced autophagy and apoptosis. This antifibrotic effect was attenuated when autophagy was inhibited using chloroquine (CQ) or 3-methyladenine (3-MA) or when apoptosis was inhibited using Z-VAD-FMK. Furthermore, whether the Sirtuin1 (SIRT1) and c-Jun N-terminal kinase (JNK) signaling pathways were associated with the resveratrol-mediated induction of autophagy and apoptosis in JS1 cells was examined. The SIRT1 inhibitor EX527 reversed autophagy, and the JNK inhibitor SP600125 reversed both autophagy and apoptosis induced by resveratrol. These findings suggest that the SIRT1 and JNK signaling pathways may be involved in the resveratrol-mediated inhibition of HSC activation by regulating autophagy and apoptosis. SIRT1 may be responsible for inducing autophagy, while JNK affects both autophagy and apoptosis. This study highlighted autophagy and apoptosis as therapeutic targets by which resveratrol can attenuate fibrosis. PRACTICAL APPLICATIONS: Resveratrol, which is a natural polyphenol found in grapes, berries, peanuts, and medicinal plants, has previously been reported to inhibit hepatic fibrosis. Since activated HSCs are the major drivers of liver fibrogenesis, many studies on the anti-hepatic fibrosis effects of resveratrol have focused on inhibiting HSC activation. The objective of this study was to evaluate the inhibitory effect of resveratrol on HSC activation and focused on the mechanism by which resveratrol modulated autophagy and apoptosis in JS1 cells, a mouse immortalized HSC line. It was shown that resveratrol inhibited HSC activation by inducing autophagy and apoptosis in a dose-dependent manner, and the mechanism may be associated with the SIRT1 and JNK signaling pathways. This study highlighted autophagy and apoptosis as therapeutic targets by which resveratrol can attenuate fibrosis. These findings may provide a new framework for understanding the mechanism by which resveratrol inhibits HSC activation.

Protective Effect of Salvianolic Acid A against N-Methyl-N-Nitrosourea-Induced Retinal Degeneration

Objective

Retinal degeneration (RD) is a serious, irreversible, and blinding eye disease, which seriously affects the visual function and quality of life of patients. At present, there is no effective method to treat RD. The final outcome of its development is photoreceptor cell oxidation and apoptosis. Therefore, looking for safe, convenient, and effective antioxidant therapy is still the key research field of Rd. In this study, the mice model of RD was induced by N-methyl-N-nitrosourea (MNU) in vivo to explore the therapeutic effect and mechanism of salvianolic acids (Sal A) on RD. In vitro, the protective effect of Sal A on MNU injured 661 W cell line of mouse retina photoreceptor cone cells was investigated preliminarily.

Methods

Male C57BL/6 mice (7–8 weeks old) received a single intraperitoneal injection (ip) of 60 mg/kg MNU or vehicle control. Treatment groups then received Sal-A 0.5 mg/kg and 1.0 mg/kg via daily intravenous injections. On day 7, functional and morphological examinations were performed, including photopic and scotopic electroretinography (ERG) and hematological analyses to observe functional changes and damage to the outer nuclear layer (ONL). On the 3rd and 7th days, the levels of superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were determined. The expression of retinal Bax, Bcl-2, and caspase-3 was quantified by Western blot and RT-PCR assays. 661 W strain of mice retinal photoreceptor cone cells were cultured in vitro and treated with 1 µm MNU. The cells in the treatment group were given 50 μM Sal A as an intervention. The growth of 661 W cells was observed and recorded under an inverted light microscope, and the activity of cells was detected by the MTT method.

Results

Sal A treatment was effective against MNU-induced RD in mice at both 0.5 mg/kg/d and 1.0 mg/kg/d doses, and the protective effect was dose-dependent. Sal A can alleviate MNU-mediated alterations to retinal ERG activity and can support maintenance of the thickness of the ONL layer. Sal A treatment increases the expression of retinal SOD and reduces the lipid peroxidation product MDA, suggesting that its protective effect is related to the oxidation resistance. It can offset changes to the expression of apoptotic factors in the retina caused by MNU treatment. Sal A mitigates MNU-mediated damage to cultured mice photoreceptor cone cells 661 W in vitro.

Conclusion

Sal A alleviates the damage caused by MNU to retinal photoreceptor cells in vivo and in vivo, and its protective effect is related to its antioxidant and antiapoptotic activities.

Synthesis and structure–activity relationships of pirfenidone derivatives as anti-fibrosis agents in vitro

Pirfenidone (PFD) was the first approved drug by FDA for the treatment of idiopathic pulmonary fibrosis (IPF). However, the rapid metabolism of 5-methyl of PFD increases the risk of side...

Salvianolic acid A attenuates steroid resistant nephrotic syndrome through suPAR/uPAR-αvβ3 signaling Inhibition

ETHNOPHARMACOLOGICAL RELEVANCE

Salvianolic acid A (SAA) is extracted from traditional Chinese medicine Salvia miltiorrhiza and is the main water-soluble and the biologically active ingredient. SAA possesses a variety of pharmacological activities and has an excellent protective effect on kidney disease, especially steroid resistant nephrotic syndrome (SRNS), and has advantages in improving the efficacy of glucocorticoids, but its mechanism needs to be further explored.

PURPOSE

The study was designed to explore the effect of suPAR and uPAR in SRNS patients and evaluate the potential effect of SAA in improving podocyte steroid resistance and explore its mechanism.

METHODS AND MATERIALS

The ELISA kits were used to detect the levels of suPAR in the blood and urine of subjects. The levels of uPAR, GRα, and GRβ expression in renal tissues of SRNS patients was detected by immunohistochemistry and analyzed using the Pearson method. In vitro studies, steroid resistance model was induced by the TNF-α and IFN-γ. The protein and mRNA expression of Nephrin, GR, GRα and GRβ were analyzed using western blot and qRT-PCR. The activity of GR-DNA binding was detected by using TransAM™ GR kits. Adriamycin further induced steroid resistance podocyte. Flow cytometry was used to detect the effect of SAA on podocyte apoptosis. ELISA assay was used to detect the suPAR expression in the podocyte supernatant. Western blot and qRT-PCR were used to detect the protein and mRNA expression of uPAR and Nephrin in podocytes.

RESULTS

The serum and urine levels of suPAR were conspicuously higher in SRNS patients than healthy volunteers and SSNS patients, and the expression of uPAR in renal tissue of SRNS patients is negatively correlated with GRα, but positively correlated with GRβ. The combination of TNF-α and IFN-γ could conspicuously increase the GRβ expression and reduce GRα/GRβ, and induce steroid resistance in podocytes. Moreover, we found that SAA could reduce the apoptosis of podocytes and suppress the expression of suPAR/uPAR, and increase the expression of Nephrin.

CONCLUSION

The level of suPAR and uPAR expression may have important value in predicting glucocorticoids resistance in patients with idiopathic nephrotic syndrome (INS). The combination of TNF-α and IFN-γ induce podocytes can establish steroid resistance model in vitro. SAA could improve glucocorticoids resistance of podocyte which can be attributed in part to regulate the suPAR/uPAR-αvβ3 signaling pathway.

Preparation and Certification of a New Salvianolic Acid A Reference Material for Food and Drug Research

Salvianolic acid A (Sal A), a water-soluble ingredient in Danshen, has various biological activities. Sal A and its impurities have similar physical and chemical properties, as well as strong reducibility; therefore, they are difficult to prepare and purify. In this study, high-purity Sal A was obtained by purification of sephadex chromatography and preparative chromatography. Furthermore, HPLC-DAD tandem ECD and HPLC-DAD tandem MS methods were used for non-volatile organic impurity analysis, ICP-MS method was used for non-volatile inorganic impurities and mass balance method and quantitative nuclear magnetic resonance were employed to certify the product. The structures of Sal A and its relative impurities were validated by nuclear magnetic resonance spectroscopy and mass spectrometry, and their contents were quantified as well. Following the principles of ISO Guides 34:2009 and 35:2005, a Sal A reference material was certified, covering homogeneity studies, stability studies, characterization, and uncertainty estimations.

Salvianolic Acid A Protects the Kidney against Oxidative Stress by Activating the Akt/GSK-3β/Nrf2 Signaling Pathway and Inhibiting the NF-κB Signaling Pathway in 5/6 Nephrectomized Rats

Salvianolic acid A (SAA) is a bioactive polyphenol extracted from Salviae miltiorrhizae Bunge, which possesses a variety of pharmacological activities. In our previous study, we have demonstrated that SAA effectively attenuates kidney injury and inflammation in an established animal model of 5/6 nephrectomized (5/6Nx) rats. However, there has been limited research regarding the antioxidative effects of SAA on chronic kidney disease (CKD). Here, we examined the antioxidative effects and underlying mechanisms of SAA in 5/6Nx rats. The rats were injected with SAA (2.5, 5, and 10 mg·kg⁻¹·d⁻¹, ip) for 28 days. Biochemical, flow cytometry, and Western blot analyses showed that SAA significantly increased the activities of total superoxide dismutase (T-SOD), glutathione peroxidase (GPx), and catalase (CAT) and lowered the levels of malondialdehyde (MDA), reactive oxygen species (ROS), and NADPH oxidase 4 (NOX-4) in a dose-dependent manner in 5/6Nx rats and in H₂O₂-induced HK-2 cells in vitro. Moreover, SAA enhanced the activation of the protein kinase B/glycogen synthase kinase-3β/nuclear factor-erythroid-2-related factor 2 (Akt/GSK-3β/Nrf2) signaling pathway in a dose-dependent manner and subsequently increased the expression of heme oxygenase-1 (HO-1) in the kidney of 5/6Nx rats, which were consistent with those obtained in H₂O₂-induced HK-2 cells in vitro shown by Western blot analysis. Furthermore, SAA significantly increased the expression of intranuclear Nrf2 and HO-1 proteins compared to HK-2 cells stimulated by LPS on the one hand, which can be enhanced by QNZ to some extent; on the other hand, SAA significantly lowered the expression of p-NF-κB p65 and ICAM-1 proteins compared to HK-2 cells stimulated by H₂O₂, which can be abrogated by ML385 to some extent. In conclusion, our results demonstrated that SAA effectively protects the kidney against oxidative stress in 5/6Nx rats. One of the pivotal mechanisms for the protective effects of SAA on kidney injury was mainly related with its antioxidative roles by activating the Akt/GSK-3β/Nrf2 signaling pathway and inhibiting the NF-κB signaling pathway.

Salvianolic Acid A Attenuates Endoplasmic Reticulum Stress and Protects Against Cholestasis-Induced Liver Fibrosis via the SIRT1/HSF1 Pathway

Background: Endoplasmic reticulum stress (ER stress) plays a critical role in the pathogenesis of liver fibrosis; thus, it can be a potential therapeutic target of fibrosis. However, the mechanism of ER stress regulation in fibrosis, particularly through sirtuin 1 (SIRT1), remains unclear. The objective of this study was to investigate the effect of SIRT1-mediated inhibition of ER stress in bile duct ligation (BDL)-induced liver fibrosis, and to explore the effect of salvianolic acid A (SalA) on BDL-induced liver fibrosis through SIRT1/heat shock factor 1 (HSF1) signaling. Materials and Methods: We explored the effects of SalA on liver fibrosis and ER stress in BDL-induced liver fibrosis in rats and the human hepatic stellate cell line LX2 cells. The LX2 cells were treated with 20 ng of platelet-derived growth factor-BB homodimer (PDGF-BB) for 24 h, and then incubated in the absence or presence of SalA (25 μM) for 24 h. Results: In vivo, SalA treatment alleviated BDL-induced liver injury and ER stress. Importantly, SalA treatment increased HSF1 expression and activity using a SIRT1-dependent mechanism. In LX2 cells, PDGF-BB induced ER stress and fibrosis were blocked by HSF1 overexpression. Furthermore, SIRT1 siRNA abrogated the SalA-mediated promotion of HSF1 deacetylation and expression, suggesting that SalA-mediated protection occurs by SIRT1 targeting HSF1 for deacetylation. Conclusion: This is the first study to identify the SIRT1/HSF1 pathway as a key therapeutic target for controlling BDL-induced liver fibrosis and to show that SalA confers protection against BDL- and PDGF-BB-induced hepatic fibrosis and ER stress through SIRT1-mediated HSF1 deacetylation.

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.

AstragalosideⅣ against cardiac fibrosis by inhibiting TRPM7 channel

BACKGROUND

Astragaloside Ⅳ (ASG-Ⅳ, (Fig. 1) is the most active component of Chinese sp. Astragalus membranaceus Bunge (Fabaceae) that has showed antioxidant, antiapoptotic and antiviral activities among others. It is reported to play an important role in cardiac fibrosis (CF), but the mechanism remains unclear.

PURPOSE

To investigate the mechanism of ASG-Ⅳ on inhibiting myocardial fibrosis induced by hypoxia.

STUDY DESIGN

We studied the relationship between anti-fibrotic effect of ASG-Ⅳ and transient receptor potential cation channel, subfamily M, member 7 (TRPM7) by in vivo and in vitro experiments.

METHODS

In vivo, CF was induced by subcutaneous isoproterenol (ISO) for 10 days. Rat hearts were resected for histological experiment and reverse transcription real-time quantitative poly merase chain reaction (RT-qPCR). In vitro, molecular and cellular biology technologies were used to confirm the anti-fibrosis effect underlying mechanism of ASG-Ⅳ.

RESULTS

Histological findings and the collagen volume fraction showed that ASG-Ⅳ decreased fibrosis in heart tissues. Hypoxia could stimulate the proliferation and differentiation of cardiac fibroblast which indicated that the degree of fibrosis was increased significantly. Anoxic treatment could also obviously up-regulate the expression of TRPM7 protein and current. ASG-Ⅳ groups showed the opposite results. Knock-down TRPM7 experiment further confirmed the role of TRPM7 channel in hypoxia-induced cardiac fibrosis.

CONCLUSION

Our results suggest that the inhibition of hypoxia-induced CF in vivo and in vitro by ASG-IV is associated with reduction of the expression of TRPM7. The moderate inhibition of the TRPM7 channel may be a new strategy for treating cardiac fibrosis.

Electrospun nanofibrils embedded hydrogel composites for cell cultivation in a biomimetic environment

(A) Schematic morphology of cells in hydrogel with and without NF. (B) Confocal laser scanning microscopic images of cells in hydrogels with and without NF.

Protective mechanisms of medicinal plants targeting hepatic stellate cell activation and extracellular matrix deposition in liver fibrosis

During chronic liver injury, hepatic stellate cells (HSC) are activated and proliferate, which causes excessive extracellular matrix (ECM) deposition, leading to scar formation and fibrosis. Medicinal plants are gaining popularity as antifibrotic agents, and are often safe, cost-effective, and versatile. This review aims to describe the protective role and mechanisms of medicinal plants in the inhibition of HSC activation and ECM deposition during the pathogenesis of liver fibrosis. A systematic literature review on the anti-fibrotic mechanisms of hepatoprotective plants was performed in PubMed, which yielded articles about twelve relevant plants. Many of these plants act via disruption of the transforming growth factor beta 1 signaling pathway, possibly through reduction in oxidative stress. This reduction could explain the inhibition of HSC activation and reduction in ECM deposition. Medicinal plants could be a source of anti-liver fibrosis compounds.

Salvianolic acid A protects RPE cells against oxidative stress through activation of Nrf2/HO-1 signaling

Reactive oxygen species (ROS) impair the physiological functions of retinal pigment epithelial (RPE) cells, which is known as one major cause of age-related macular degeneration. Salvianolic acid A (Sal A) is the main effective aqueous extract of Salvia miltiorrhiza. The aim of this study was to test the potential role of Sal A against oxidative stress in cultured RPE cells and to investigate the underlying mechanistic signaling pathways. We observed that Sal A significantly inhibited hydrogen peroxide (H2O2)-induced primary and transformed RPE cell death and apoptosis. H2O2-stimulated mitogen-activated protein kinase activation, ROS production, and subsequent proapoptotic AMP-activated protein kinase activation were largely inhibited by Sal A. Further, Sal A stimulation resulted in a fast and dramatic activation of Akt/mammalian target of rapamycin complex 1 (mTORC1) signaling, followed by phosphorylation, accumulation, and nuclear translocation of the NF-E2-related factor 2 (Nrf2), along with increased expression of the antioxidant-response element-dependent gene heme oxygenase-1 (HO-1). Both Nrf2 and HO-1 were required for Sal A-mediated cytoprotective effect, as Nrf2/HO-1 inhibition abolished Sal A-induced beneficial effects against H2O2. Meanwhile, the PI3K/Akt/mTORC1 chemical inhibitors not only suppressed Sal A-induced Nrf2/HO-1 activation, but also eliminated its cytoprotective effect in RPE cells. These observations suggest that Sal A activates the Nrf2/HO-1 axis in RPE cells and protects against oxidative stress via activation of Akt/mTORC1 signaling.

Salvianolic acid A inhibits angiotensin II-induced proliferation of human umbilical vein endothelial cells by attenuating the production of ROS

AIM

To investigate the action of salvianolic acid A (SalA) on angiotensin II (Ang II)-induced proliferation of human umbilical vein endothelial cells (HUVECs) and the possible signaling pathways mediating this action.

METHODS

Cell proliferation was examined with MTT assay. The expression levels of Src phosphorylation (phospho-Src), Akt phosphorylation (phospho-Akt), and NADPH oxidase 4 (Nox4) in HUVECs were determined by Western blot. The production of reactive oxygen species (ROS) was estimated using fluorescence-activated cell sorting (FACS).

RESULTS

SalA (6.25-50 μmol/L) did not affect the viability of HUVECs. Treatment of HUVECs with Ang II (1 μmol/L) markedly increased the cell viability; pretreatment of HUVECs with SalA (12.5, 25 and 50 μmol/L) prevented Ang II-induced increase of the cell viability in a concentration-dependent manner. Treatment of HUVECs with Ang II (1 μmol/L) markedly up-regulated the protein expression levels of phospho-Src, phospho-Akt (473) and Nox4; pretreatment of HUVECs with SalA (12.5, 25 and 50 μmol/L) blocked all the effects in a concentration-dependent manner. Treatment of HUVECs with Ang II (1 μmol/L) dramatically increased ROS production in HUVECs; pretreatment of HUVECs with SalA (12.5, 25 and 50 μmol/L) blocked the ROS production in a concentration-dependent manner.

CONCLUSION

SalA inhibits Ang II-induced proliferation of HUVECs via reducing the expression levels of phospho-Src and phospho-Akt (473), thereby attenuating the production of ROS.

Interactions between spider silk and cells--NIH/3T3 fibroblasts seeded on miniature weaving frames

Background

Several materials have been used for tissue engineering purposes, since the ideal matrix depends on the desired tissue. Silk biomaterials have come to focus due to their great mechanical properties. As untreated silkworm silk has been found to be quite immunogenic, an alternative could be spider silk. Not only does it own unique mechanical properties, its biocompatibility has been shown already in vivo. In our study, we used native spider dragline silk which is known as the strongest fibre in nature.

Methodology/Principal Findings

Steel frames were originally designed and manufactured and woven with spider silk, harvesting dragline silk directly out of the animal. After sterilization, scaffolds were seeded with fibroblasts to analyse cell proliferation and adhesion. Analysis of cell morphology and actin filament alignment clearly revealed adherence. Proliferation was measured by cell count as well as determination of relative fluorescence each after 1, 2, 3, and 5 days. Cell counts for native spider silk were also compared with those for trypsin-digested spider silk. Spider silk specimens displayed less proliferation than collagen- and fibronectin-coated cover slips, enzymatic treatment reduced adhesion and proliferation rates tendentially though not significantly. Nevertheless, proliferation could be proven with high significance (p<0.01).

Conclusion/Significance

Native spider silk does not require any modification to its application as a biomaterial that can rival any artificial material in terms of cell growth promoting properties. We could show adhesion mechanics on intracellular level. Additionally, proliferation kinetics were higher than in enzymatically digested controls, indicating that spider silk does not require modification. Recent findings concerning reduction of cell proliferation after exposure could not be met. As biotechnological production of the hierarchical composition of native spider silk fibres is still a challenge, our study has a pioneer role in researching cellular mechanics on native spider silk fibres.

Effect of salvianolic acid A on vascular reactivity of streptozotocin-induced diabetic rats

AIMS

The present study aims to evaluate the beneficial effect of salvianolic acid A (SAA) on the alterations in vascular reactivity of streptozotocin (STZ)-induced diabetic rats.

MAIN METHODS

Diabetes was induced by a single intraperitoneal injection of STZ (60 mg/kg). Following 16 weeks of SAA treatment (1 mg/kg/day), thoracic aortic rings of rats were mounted in organ baths. Contractile responses to noradrenaline (NA) and KCl and relaxant responses to acetylcholine (ACh) and sodium nitroprusside (SNP) were assessed.

KEY FINDINGS

Loss of weight, hyperglycemia, elevated content of malondialdehyde (MDA) and decline of total antioxidant capacity (TAC) were observed in diabetic rats. SAA could reverse these metabolic and biochemical abnormalities. Compared to the control, the maximum contraction (E(max)) to NA, but not sensitivity (pD(2)), increased significantly in diabetic aortas, which was prevented by SAA treatment. However, the response of rat aortas to KCl (E(max) and pD(2)) was not altered either in diabetic group or SAA treatment compared with that of normal control group. We also observed the significant decrease in relaxation to ACh rather than SNP in diabetic group compared with controls, and SAA treatment could revert the ACh response.

SIGNIFICANCE

It is concluded that oral administration of SAA can significantly improve glucose metabolism and inhibit oxidative injury as well as protect against impaired vascular responsiveness in STZ-induced diabetic rats.

Characterization of metabolites in rat plasma after intravenous administration of salvianolic acid A by liquid chromatography/time-of-flight mass spectrometry and liquid chromatography/ion trap mass spectrometry

Salvianolic acid A (SalA) is one of the main active constituents in Salvia miltiorrhiza (Danshen). Although the pharmacokinetics of SalA in rats after intravenous (i.v.) administration of Danshen injection has been reported, the information relevant to the metabolites of SalA in vivo is absent so far. In this study, by means of liquid chromatography with time-of-flight mass spectrometry (LC/TOFMS) and liquid chromatography with ion trap mass spectrometry (LC/MS(n)) techniques, the unknown metabolites of SalA in rat plasma after i.v. administration of the purified SalA at the dose of 20 mg/kg body weight were identified. A liquid-liquid extraction method was established to separate the metabolites from the plasma and the chromatographic separations were performed on a Xterra MS C(18) column (100 mm x 4.6 mm i.d., 3.5 microm) with acetonitrile/methanol/water/formic acid (20.5:19.5:64: 0.05, v/v/v/v) as the mobile phase at a constant flow rate of 0.2 mL/min. Based on the data obtained from the LC/TOFMS determination (the total ion chromatograms, MS spectra and extracted ion chromatograms), in combination with the characteristic fragment ions acquired from the LC/MS(n) determination, five metabolites were identified as SalA-monoglucuronide, monomethyl-SalA-monoglucuronide, mono-methyl-SalA, dimethyl-SalA and dimethyl-SalA-monoglucuronide, and the possible chemical structures were deduced. The results indicated that SalA might mainly undergo two metabolic pathways in vivo in rats, which were methylation and glucuronidation. The present studies have laid a solid foundation for the metabolic mechanism of SalA in vivo.

A sensitive method for determination of salvianolic acid A in rat plasma using liquid chromatography/tandem mass spectrometry

Salvianolic acid A (SAA), a major effective constituent of Salvia miltiorrhizas, is widely used in traditional Chinese medicine. A sensitive rapid analytical method was established and validated for SAA in rat plasma, which was further applied to assess the pharmacokinetics of SAA in rats receiving a single oral dose of SAA. The method used liquid chromatography tandem mass spectrometry in multiple reaction monitoring mode with chloramphenicol as the internal standard. A simple liquid-liquid extraction based on ethyl acetate was employed. The combination of a simple sample cleanup and short chromatographic run time (3 min) increased the throughput of the method substantially. The method was validated over the range 1.4-1000 ng/mL with a correlation coefficient >0.99. The lower limit of quantification was 1.4 ng/mL for SAA in plasma. Intra- and inter-day accuracies for SAA were 95-113 and 98-107%, and the inter-day precision was less than 12%. This method is more sensitive and faster than previous methods. After a single oral dose of 100 mg/kg of SAA, the mean peak plasma concentration (Cmax) of SAA was 318 ng/mL at 0.5 h, the area under the plasma concentration-time curve (AUC0-12 h) was 698 +/- 129 ng.h/mL, and the elimination half-life (T1/2) was 3.29 h.

Effect of Chinese traditional compound, Gan-fu-kang, on CCl(4)-induced liver fibrosis in rats and its probable molecular mechanisms

AIM

To explore the antifibrotic effect of traditional Chinese medicine compound Gan-fu-kang (GFK) on CCl(4)-induced liver fibrosis in rats and its probable mechanisms.

METHODS

The effects of GFK on CCl(4)-induced liver fibrosis were tested in rats. The liver histopathology was examined by light microscope, polaring microscope and electron microscope. The activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were assayed and the content of albumin (ALB) and hydroxyproline in the liver was measured. The expression of transforming growth factor-beta(1) (TGF-beta(1)) and laminin (LN) was determined by immunohistochemistry. Semi-quantitive computation of collagen types I and III and laminin was done. The expression of MMP-2 and TIMP-1 was assayed by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Upon pathological examination, GFK treatment had significantly reversed liver fibrosis. Hepatic extracellular matrix (ECM) deposition was significantly reduced, as evidenced by the reduction of the content of hydroxyproline, collagen types I and III, and laminin. Hepatic function was improved by GFK treatment, as evidenced by the increase of plasma ALB and A/G, and by the decrease of serum ALT and AST. TGF-beta(1) in liver was significantly reduced. A significant expression of MMP-2 and TIMP-1 mRNA in liver were downregulated after GFK treatment.

CONCLUSION

The traditional Chinese medicine compound recipe GFK has an antifibrotic effect on CCl(4)-induced liver fibrosis in rats, which improves hepatic function and lessens the deposition of collagen in the liver. The probable antifibrotic mechanisms were: inhibiting the expression of TGF-beta(1) and decreasing expressions of MMP-2 and TIMP-1.

Pharmacokinetic study of salvianolic acid A in rat after intravenous administration of Danshen injection

In order to research the pharmacokinetics of salvianolic acid A (SalA), a herbal ingredient isolated from Salvia miltiorrhiza Bunge, after intravenous administration to rats, a specific and accurate high-performance liquid chromatography (HPLC) was developed. The assay procedure involved simple liquid-liquid extraction of SalA and internal standard (IS, ethyl-p-hydroxybenzoate) from plasma into ethyl acetate. The organic layer was separated and evaporated under reduced pressure at 40 degrees C. The residue was reconstituted in the mobile phase and analyzed on an Inertsil C8 column, monitored at 285 nm. The mobile phase, which consisted of methanol-acetonitrile-water-formic acid (10:20:70:0.4, by vol), was used at a flow rate of 1.0 mL/min. The ratio of the peak area of the analyte to IS was applied to quantify the plasma samples. The standard curve for SalA was linear (r2 = 0.9999) in the concentration range of 0.75-150 microg/mL. The limit of quantitation (LOQ) of SalA was 0.75 microg/mL. The intra- and inter-day precisions (RSD) of the quality control (QC) samples were in the ranges of 2.17-3.29 and 1.24-5.28%, respectively. Accuracy in the measurement of QC samples ranged from 94.7 to 101.1%. This method was validated for specificity, accuracy and precision and was successfully applied to the pharmacokinetic study of SalA in rat plasma after intravenous administration of Danshen injection.

Antiproliferative effect of salvianolic acid A on rat hepatic stellate cells

Suppression of activation or proliferation, or induction of apoptosis in hepatic stellate cells (HSCs) have been proposed as therapeutic strategies against liver fibrosis. Salvia miltiorrhiza has been reported to exert antifibrotic effects in rats with hepatic fibrosis, but its mechanisms of action remain to be clarified. We have investigated the effects of salvianolic acid A (Sal A), an active principle from S. miltiorrhiza, on the proliferation-related biomarkers in a cell line of rat HSCs (HSC-T6) stimulated with platelet-derived growth factor-BB homodimer (PDGF-BB). DNA synthesis (bromodeoxyuridine (BrdU) incorporation), cell cycle related proteins and apoptosis markers were determined to evaluate the inhibitory effects of Sal A. The results showed that Sal A (1-10 microM) concentration-dependently attenuated PDGF-BB-stimulated proliferation (BrdU incorporation) in HSC-T6 cells. Sal A at 10 microM induced cell apoptosis in PDGF-BB-incubated HSCs, together with a reduction of Bcl-2 protein expression, induction of cell cycle inhibitory proteins p21 and p27, and down-regulation of cyclins D1 and E, suppression of Akt phosphorylation, reduction in PDGF receptor phosphorylation, and an increase in caspase-3 activity. Sal A exerted no direct cytotoxicity on primary hepatocytes and HSC-T6 cells under experimental concentrations. Our results suggested that Sal A inhibited PDGF-BB-activated HSC proliferation, partially through apoptosis induction.

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Effect of compound rhodiola sachalinensis A Bor on CCl4-induced liver fibrosis in rats and its probable molecular mechanisms

AIM: To explore the anti-fibrotic effect of a traditional Chinese medicine, compound rhodiola sachalinensis A Bor on CCl₄-induced liver fibrosis in rats and its probable molecular mechanisms.

METHODS: Ninety healthy male SD rats were randomly divided into three groups: normal group (n = 10), treatment group of compound rhodiola sachalinensis A Bor (n = 40) and CCl₄-induced model group (n = 40). The liver fibrosis was induced by CCl₄ subcutaneous injection. Treatment group was administered with compound rhodiola sachalinensis A Bor (0.5 g/kg) once a day at the same time. Then the activities of several serum fibrosis-associated enzymes: alanine aminotransferase (ALT), aspartate aminotransferase (AST), N-acetyl-beta-D-glucosaminidase (β-NAG) and the levels of serum procollagen III (PC III), collagen IV (C IV), hyaluronic acid (HA) were assayed. The histopathological changes were observed with HE, VG and Masson stain. The expression of TGF-β1 mRNA, α1 (I) mRNA and Na⁺/Ca²⁺ exchanger (NCX) mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR) in situ.

RESULTS: Compound rhodiola sachalinensis A Bor significantly reduced serum activities of ALT, AST, β-NAG and decreased the levels of PC III, C IV, HA, improved the liver histopathological changes, inhibited the expression of TGF-β1 mRNA, α(I) mRNA and Na⁺/Ca²⁺ exchanger mRNA in rats.

CONCLUSION: Compound rhodiola sachalinensis A Bor can intervene in CCl₄-induced liver fibrosis in rats, in which potential mechanisms may be decreasing the production of TGF-β1, reducing the production of collagen, preventing the activation of hepatic stellate cell (HSC) and inhibiting the expression of TGF-β1 mRNA, α1(I) mRNA and Na⁺/Ca²⁺ exchanger mRNA.

Protective effects of Rhodiola sachalinesis A Bor on CCl4-induced liver fibrosis in rats

AIM

To study the protective effects of Rhodiola schalinensis A Bor on CCl4-induced liver fibrosis.

METHODS: Male SD rats were divided into 3 groups: normal(N), Rhodiola sachalinesis A Bor(R) and model(M) group. The M and R group were given 300 ml/L CCl₄(3ml/kg, 2 times/week) for 15 weeks and Rhodiola sachalinesis A Bor (0.5g/kg, p.o., daily for 15 weeks) was administered to rats of R group. Histopathological changes were examined. The changes of hepatic content of hydroxyproline and expression of α1(Ⅰ)mRNA were observed.

RESULTS

Rhodiola sachalinesis A Bor decreased the hepatic content of hydroxyproline (657±74 μg/g vs 1 257±98 μg/g, P<0.05) and severity of hepatic fibrosis, improved the liver histopathological changes and inhibited the expression of α1(Ⅰ) mRNA and decreased the level of HA, CⅣ, PCⅢ and TGFβ1 (164±46 μg/L, 97±15 μg/L, 289±76 μg/L, 60±20 mg/L vs 265±98 μg/L, 160±30 μg/L, 456±113 μg/L, 89±23 mg/L. P<0.05, P<0.01).

CONCLUSION

Rhodiola sachalinesis A Bor is effective in protecting against CCl4-induced liver fibrosis in rats, its machenisms appear to be associated with the inhibition of collagen production and protection of hepatic cells.

Experimental study of effect of Ganyanping on fibrosis in rat livers

AIM: To observe the effects of Ganyanping on CCl₄-induced hepatic fibrosis in rats.

METHODS: The rats were separated randomly into five groups. Groups A to group D, each consisting of 15 rats, were for different tests, while 8 rats were used as normal controls (N). For group D, CCl₄ was injected subcutaneously, at a dosage of 3 mL/kg for 9 wk. For group A, Ganyanping was administered via gastric tube at a dosage of 10 mL/kg. For group B, the treatment with Ganyanping was started 4 wk after CCl₄ administration. In group C, Ganyanping was administered 8 wk after the intoxication, and treatment lasted for 4 wk. Liver tissues were fixed in 10% formalin and embedded in paraffin. Pathologic changes, particularly fibrosis, were evaluated on the HE and V-G-stained sections. Ten middle-power fields were randomly selected for assessment of collagen deposition.

RESULTS: Loss of normal hepatic architecture, some with pseudo-lobule formation, was observed in group D, while hepatocytes steatosis and fibrosis were less pronounced in the animals treated with Ganyanping. Pseudo-lobule formation was not evident in the latter groups. The total collagen area and ratio were 840.23 ± 81.65 and 7.0 ± 0.9, respectively in group D, the ratio being reduced greatly in the Ganyanping-treated groups (148.73 ± 45.89 and 1.16 ± 0.33, respectively). The activities of MAO and ACP were elevated and that of SDH in group D decreased in the hepatic tissue as compared to the control group. The treatment with Ganyanping abrogated these enzymatic changes.

CONCLUSION: Our data approved that Ganyanping could improve the microcirculation in the liver, reduce oxygen-derived free radicals, and enhance the cellular metabolism and immune function, all resulting in an anti-fibrotic effect. Hence, Ganyanping can protect the liver from fibrosis. It may be a safe and effective preparation for patient with fibrosis.

Salvia miltiorrhiza monomer IH764-3 induces hepatic stellate cell apoptosis via caspase-3 activation

AIM: To investigate the effects of IH764-3 on HSC apoptosis, and the expression of caspase-3 protein in HSC apoptotic process.

METHODS: HSCs were cultured in medium with different IH764-3 doses (10 μg·mL^-1, 20 μg·mL^-1, 30 μg·mL^-1, 40 μg·mL^-1) and without IH764-3, and HSC proliferation was quantitatively measured by ³H-thymidine incorporation. The morphological changes of HSCs were observed with transmission electron microscope after exposure to the dose of 40 μg·mL^-1 of IH764-3 for 48 hr. The apoptosis rates were detected by annexin V/PI and TdT-mediated dUTP nick end labeling (TUNEL). The expression of caspase-3 protein was determined by flow cytometry.

RESULTS: (1) HSC proliferation rates induced with different IH764-3 doses (10 μg·mL^-1, 20 μg·mL^-1, 30 μg·mL^-1, 40 μg·mL^-1) were significantly reduced compared with that of the control group (P < 0.01). (2) With the doses above, IH764-3 dose-dependently produced HSC apoptosis rates of 6.7% (9.4%), 9.3% (21.6%), 15.1% (27.2%) and 19.0% (28.4%) respectively, by annexin V and PI-labeled flow cytometry assay (or TUNEL), while it was only 2.3% (6.7%) in the control. (3) The expression of caspase-3 protein in IH764-3 groups was significantly higher than that of the control (P < 0.05).

CONCLUSION: Within the dose range used in present study, IH764-3 can inhibit HSC proliferation, as well as enhance HSC apoptosis. Furthermore, IH764-3 can significantly increase the caspase-3 protein expression.

Effects of Yigan Decoction on proliferation and apoptosis of hepatic stellate cells

AIM: To investigate the effects of Chinese herb Yigan Decoction on proliferation and apoptosis of the hepatic stellate cells (HSC) in vitro.

METHODS: The study in vitro was carried out in the culture of HSC lines. Various concentrations of Yigan Decoction were added and incubated. Cell proliferation was detected with MTT colorimetric assay. Cell apoptosis was detected by electron microscopy, flow cytometry and TUNEL.

RESULTS: The proliferation of HSC was inhibited by Yigan Decoction, which depending on dose and time significantly. The HSC proliferation rates of groups at the end concentrations 144 and 72 (g·L^-1) were 21.62% and 40.54% respectively, significantly lower than that of normal control group (P < 0.01). The HSC proliferation rates of groups at the end concentrations 36, 18 and 9 (g·L^-1) were 54.05%, 45.95% and 51.35% respectively, lower than that of control group (P < 0.05). When the end concentration was 4.5 g·L^-1, the proliferation rate was 83.78%, which appeared no significant differences compared with control group. At the same concentrations of 18 g·L^-1, the inhibitory effects of Yigan Decoction at 24 h, 48 h and 72 h time point were observed, the effects were time-dependent, and reached a peak at 72 h. Meanwhile, it was showed that the inducing effects of Yigan Decoction on HSC apoptosis were dose-dependent and time-dependent. The apoptosis index (AI) was detected by TUNEL. After Yigan Decoction had been incubated for 48 h at the end concentration of 18 g·L^-1, the AI (14.5 ± 3.1)% was significantly higher than that of control group (4.3 ± 1.3)% (P < 0.01). When visualized under transmission electron microscopy, some apoptotic stellate cells were found, i.e. dilated endoplasmic reticulum, irregular nuclei, chromatin condensation and heterochromatin ranked along inside of nuclear membrane. By flow cytometry detection, after HSC was treated with Yigan Decoction at different concentrations of 36, 18 and 9 (g·L^-1) for 48 h, AI (%) were 13.3 ± 3.2, 10.7 ± 2.7 and 10.1 ± 2.5 respectively, which were significantly higher than that of control group (4.1 ± 1.9) (P < 0.01). At the same concentration of 18 g· L^-1 for 24 h, 48 h and 72 h, AI (%) were 9.3 ± 1.8, 10.7 ± 2.7 and 14.6 ± 4.3 respectively, which were significantly higher than that of control group (P < 0.01).

CONCLUSION: Yigan Decoction could significantly inhibit HSC proliferation and increase the apoptosis index of HSC dose-dependently and time-dependently, which may be related to its mechanism of antifibrosis.

Sleep deprivation increase the expression of inducible heat shock protein 70 in rat gastric mucosa

AIM: To investigate if sleep deprivation is able to increase the expression of inducible heat shock protein 70 in gastric mucosa and its possible role in mucosal defense.

METHODS: Rats for sleep disruption were placed inside a computerized rotating drum, gastric mucosa was taken from rats with 1, 3 and 7 d sleep deprivation. RT-PCR, immunohistochemistry and Western blotting were used to determine the expression of heat shock protein 70. Ethanol (500 mL·L^-1, i.g.) was used to induce gastric mucosa damage.

RESULTS: RT-PCR, Western blotting and immunostaining confirmed that the sleep deprivation as a stress resulted in significantly greater expression of inducible heat shock protein 70 in gastric mucosa of rats. After the 500 mL·L^-1 ethanol challenge, the ulcer area found in the rats with 7 d sleep deprivation (19.15 ± 4.2) mm² was significantly lower (P < 0.01) than the corresponding control (53.7 ± 8.1) mm².

CONCLUSION: Sleep deprivation as a stress, in addition to lowering the gastric mucosal barrier, is able to stimulate the expression of inducible heat shock protein 70 in gastric mucosa of rats, the heat shock protein 70 may play an important role in gastric mucosal protection.

Expression changes of activin A in the development of hepatic fibrosis

AIM: To examine the expression of activin A, a member of the transforming growth factor (TGF-β) superfamily, recently has been reported to beoverexpressed in liver cirrhosis, in the course of carbon tetrachloride-induced rat hepatic fibrosis.

METHODS: Hepatic fibrosis was induced in rats by subcutaneous injections of 40% carbon tetrachloride oily solution for a period of 1 to 7 weeks. At the end of 1, 2, 3, 4, 5, 6 and 7 weeks after carbon tetrachloride injections, the rats were killed in group (6-10 rats each time) for study. The activin A messenger RNA expression and its protein localization were assessed by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemistry.

RESULTS: The normal rat liver expressed activin A mRNA and protein, and its expression was transiently decreased and became undetectable after carbon tetrachloride injections for 2 or 3 weeks and then increased gradually. After injection of carbon tetrachloride for 6 and 7 weeks, activin A mRNA and protein expressions were significantly enchanced in rat liver. Compared with that of the normal rat liver. Activin A mRNA expression levels in rats receiving carbon tetrachloride injections for 6 and 7 weeks were 1.6 and 2.2 times that of those in normal rat liver respectively (0.456 ± 0.094 vs 0.286 ± 0.0670, P < 0.01; 0.620 ± 0.134 vs 0.286 ± 0.0670, P < 0.01). Immunohistochemistry showed that activin A expressed in hepatocytes of normal liver, and its expression was decreased in rats receiving carbon tetrachloride for 2 or 3 weeks. Compared with normal liver, activin A expression distribution mode changed in fibrotic liver, being increased significantly in hepatocytes around fibrotic areas.

CONCLUSION: Activin A expression was increased in late stage of hepatic fibrosis, and this may be involved in hepatic fibrosis formation in this period.