Changcheng Zhang

Cardioprotective effects of saponins from Panax japonicus on acute myocardial ischemia against oxidative stress-triggered damage and cardiac cell death in rats.

AIM To study the cardioprotective effects of saponins from Panax japonicus (SPJ) on acute myocardial ischemia injury rats induced by ligating of the left anterior descending branch (LAD), on the basis of this investigation, the possible mechanism of SPJ was elucidated. MATERIALS AND METHODS SPJ was identified by high performance liquid chromatography-evaporative light scattering detection. Male Sprague-Dawley rats (200-220g) were randomly divided into four groups: sham-operated, LAD, LAD+l-SPJ (SPJ, 50mg/kg/day, orally) and LAD+h-SPJ (SPJ, 100mg/kg/day, orally). Before operation, the foregoing groups were pretreated with homologous drug once a day for 7 days, respectively. After twelve hours in LAD, the cardioprotective effects of SPJ were evaluated by infarct size, biochemical values, hemodynamic, and histopathological observations and the antioxidative and antiapoptotic relative gene expressions. RESULTS SPJ significantly improved heart function and decreased infarct size; remarkably decreased levels of serum lactate dehydrogenase, creatine kinase, xanthine oxide and malondialdehyde content, increased contents of serum total antioxidant capacity, superoxide dismutase (SOD), glutathione peroxidase, catalase; quantitative real-time PCR results showed that SPJ might markedly reverse the down-regulated mRNA expressions of the SOD1, SOD2 and SOD3, ameliorate the increased Bax and caspase-3 mRNA expressions and decreased Bcl-2 mRNA expression and ratios of Bcl-2 to Bax. Histopathological observations provided supportive evidence for biochemical analyses, and with the dose of SPJ increasing, the aforesaid improvement became more and more strong. CONCLUSIONS The studies demonstrated that in ischemic myocardium, oxidative stress caused the overgeneration and accumulation of reactive oxygen species (ROS), which was central of cardiac ischemic injury. SPJ exerted beneficially cardioprotective effects on myocardial ischemia injury rats, mainly scavenging oxidative stress-triggered overgeneration and accumulation of ROS, alleviating myocardial ischemia injury and cardiac cell death.

MiRNA-194 Regulates Palmitic Acid-Induced Toll-Like Receptor 4 Inflammatory Responses in THP-1 Cells

There is strong evidence to suggest that inflammatory responses link obesity and diseases, and the understanding of obesity-induced inflammatory mechanisms is central to the pathogenesis of diseases such asnonalcoholic fatty liver disease(NAFLD) and atherosclerosis that are modified by obesity. Based on this, anti-inflammatory treatments become a potential therapies for obesity-related diseases like NAFLD.A critical role of toll-like receptor (TLR) and its downstream molecules such as tumor necrosis factor receptor-associated factor 6(TRAF6) has been documented in inflammatory response induced by fatty acid. TLR pathway regulation provides a new insight to controlling the inflammatory response induced by fatty acid. Taken together, our study was aimed to understand the mechanism of fatty acid-mediated inflammation and look for an effective target which can prevent the inflammatory response induced by obesity. In this study, we used the saturated fatty acid palmitic acid (PA) to activate TLR4 signal pathway in human monocyte cells THP-1 that established an intracellular inflammatory model. Followed with activated TLR4, downstream molecular TRAF6 was upregulated and ultimately induced proinflammatory cytokine production. Based on this model, we also found that PA downregulated miR-194 expression with TLR4 activation. Moreover, our results showed that key signal molecular TRAF6 is a target of miR-194, overexpression of miR-194 directly decreased TRAF6 expression and attenuated the release of proinflammatory cytokine TNF-α in PA-activated monocyte THP-1. We conclude that miR-194 negatively regulates the TLR4 signal pathway which is activated by PA through directly negative TRAF6 expression.

Saponins from Panax japonicus attenuate D-galactose-induced cognitive impairment through its anti-oxidative and anti-apoptotic effects in rats

To investigate the neuroprotective effects of saponins from Panax japonicus (SPJ) on D‐galactose (D‐gal)‐induced brain ageing, and further explore the underlying mechanisms.

Protective effects of total flavonoids from Epimedium on the male mouse reproductive system against cyclophosphamide-induced oxidative injury by up-regulating the expressions of SOD3 and GPX1.

Total flavonoids of Epimedium (TFE) is the main active composition of Epimedium that has been used to treat male reproductive problems. The present aim was to investigate the protective effects of TFE on male mice reproductive system against cyclophosphamide (CP)‐induced oxidative injury. The animals were treated with CP to make testicular injury model and the protective effects of TFE were observed. In the CP‐treated group, testicular and epididymal weights, sperm count and motility significantly decreased relative to the control group (P < 0.05 and P < 0.01, respectively). Compared with the CP‐treated group, TFE (200 and 400 mg/kg) treated mice increased testicular weights by 21.6% and 28.4% (P < 0.05), sperm counts by 81.7% and 148.3% (P < 0.01) and sperm motility by 47.2% and 61.3% (P < 0.01). Meanwhile, the CP‐treated group showed enhancement of lipid peroxidation leading to testicular reproductive toxicity. TFE restored these oxidative damages by up‐regulating the expression of antioxidant enzymes, especially SOD3 and GPX1. TUNEL assay and histopathological observations provided supportive evidence for above results, and when the dose of TFE increased, the aforesaid improvement became more and more strong. These results demonstrated that TFE exerted beneficially protective effects on the structural and functional damage of male mice reproductive system and reduced apoptosis in spermatogenic cells by inhibiting CP‐induced oxidative stress. Copyright

Chikusetsu Saponin V Attenuates MPP+-Induced Neurotoxicity in SH-SY5Y Cells via Regulation of Sirt1/Mn-SOD and GRP78/Caspase-12 Pathways

Studies have shown that saponins from Panax japonicus (SPJ) possess neuroprotective effects. However, whether Chikusetsu saponin V (CsV), the most abundant member of SPJ, can exert neuroprotective effects against 1-methyl-4-phenylpyridinium ion (MPP+)-induced cytotoxicity is not known. In this study, we aimed to investigate the neuroprotective effects of CsV on MPP+-induced cytotoxicity in human neuroblastoma SH-SY5Y cells and explore its possible mechanisms. Our results show that CsV attenuates MPP+-induced cytotoxicity, inhibits ROS accumulation, and increases mitochondrial membrane potential dose-dependently. We also found that levels of Sirt1 protein and Mn-SOD mRNA significantly decreased in MPP+-treated group but were restored with CsV treatment in a dose-dependent manner. Furthermore, GRP78 protein and Caspase-12 mRNA levels were elevated by MPP+ exposure but reversed by CsV treatment. CsV inhibited the MPP+-induced downregulation of Bcl-2 and up-regulation of Bax in a dose-dependent manner and, thus, increased the ratio of Bcl-2/Bax. Overall, these results suggest that Sirt1/Mn-SOD and GRP78/Caspase-12 pathways might be involved in the CsV-mediated neuroprotective effects.

Chikusetsu saponin V attenuates H2O2-induced oxidative stress in human neuroblastoma SH-SY5Y cells through Sirt1/PGC-1α/Mn-SOD signaling pathways

Oxidative stress plays a vital role in the pathogenesis of neurodegenerative diseases. Chikusetsu saponin V (CsV), the most abundant member of saponins from Panax japonicus (SPJ), has attracted increasing attention for its potential to treat neurodegenerative diseases. However, the mechanisms are unclear. Our study intended to investigate the antioxidative effects of CsV in human neuroblastoma SH-SY5Y cells. Our data showed that CsV attenuated H2O2-induced cytotoxicity, inhibited ROS accumulation, increased the activities of superoxide dismutase (SOD) and GSH, and increased mitochondrial membrane potential dose-dependently. Further exploration of the mechanisms showed that CsV exhibited these effects through increasing the activation of oxidative-stress-associated factors including Sirt1, PGC-1α, and Mn-SOD. Moreover, CsV inhibited H2O2-induced down-regulation of Bcl-2 and up-regulation of Bax in a dose-dependent manner and, thus, increased the ratio of Bcl-2/Bax. In conclusion, our study demonstrated that CsV exhibited neuroprotective effects possibly through Sirt1/PGC-1α/Mn-SOD signaling pathways.

Chikusetsusaponin V inhibits inflammatory responses via NF-κB and MAPK signaling pathways in LPS-induced RAW 264.7 macrophages

Abstract Excessive activation of macrophages is implicated in various inflammation resulted injuries. Saponins from Panax japonicus (SPJ) have been shown to possess anti-inflammatory activities. However, whether Chikusetsusaponin V (CsV), the most abundant component of SPJ, can exert anti-inflammatory activities is unknown. The present study was aimed to investigate the anti-inflammatory effects of CsV in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells and the underlying mechanisms. Our data showed that CsV dose-dependently inhibited NO, iNOS, TNF-α and IL-1β expressions in LPS-stimulated RAW264.7 cells. Increased protein levels of nuclear NF-κB and elevated phosphorylation levels of ERK and JNK in LPS-stimulated RAW 264.7 cells were also found downregulated by CsV treatment. Furthermore, the increase of CD14 and TLR4 mRNA expression due to LPS stimulation were significantly reversed by CsV treatment. These results suggested that CsV attenuated LPS-induced inflammatory responses partly via TLR4/CD14-mediated NF-κB and MAPK pathways.

Chikusetsu saponin IVa ameliorates high fat diet-induced inflammation in adipose tissue of mice through inhibition of NLRP3 inflammasome activation and NF-κB signaling

Chronic metabolic inflammation in adipose tissue plays an important role in the development of obesity-associated diseases. Our previous study indicated that total saponins of Panax japonicus (SPJ) rhizoma and Chikusetsu saponin V, one main component of SPJ, could exert the anti-oxidative and anti-inflammatory effects. The present study aimed to investigate the in vivo and Ex vivo anti-inflammatory activities of another main component of SPJ, namely Chikusetsu saponin IVa (CS). CS could significantly inhibited HFD-induced lipid homeostasis, and inhibited inflammation in adipose tissue, as reflected by the decreased mRNA expression levels of inflammation-related genes and secretion of the chemokines/cytokines, inhibited the accumulation of adipose tissue macrophages (ATMs) and shifted their polarization from M1 to M2, suppressed HFD-induced expression of NLRP3 inflammasome component genes and decreased IL-1β and Caspase-1 production in mice. Moreover, CS treatment also inhibited the activation of NLRP3 inflammasome in bone marrow-derived macrophages (BMDMs). Meanwhile, CS treatment inhibited an NLRP3-induced ASC pyroptosome formation and lipopolysaccharide (LPS)-induced pyroptosis. Furthermore, CS treatment suppressed HFD-induced NF-κB signaling in vivo and LPS-induced NF-κB activation as reflected by the fact that their phosphorylated forms and the ratios of pNF-κB/NF-κB, pIKK/IKK, and pIκB/IκB were all decreased in EAT from HFD-fed mice treated with CS as compared with those of HFD mice. Taking together, this study has revealed that CS effectively inhibits HFD-induced inflammation in adipose tissue of mice through inhibiting both NLRP3 inflammasome activation and NF-κB signaling. Thus, CS can serve as a potential therapeutic drug in the prevention and treatment of inflammation-associated diseases.

Vaccine adjuvant ginsenoside Rg1 enhances immune responses against hepatitis B surface antigen in mice

The adjuvant effect of ginsenoside Rg1 on immune responses against hepatitis B surface antigen (HBsAg) in mice was investigated. Female BALB/c mice were subcutaneously injected with saline or HBsAg antigen with or without Rg1 on days 7 and 21. Samples were collected 2 weeks after the boosting for the detection of anti-HBsAg immunoglobulin G (IgG) isotypes in sera and gamma interferon (IFN-γ) and interleukin-4 (IL-4) produced in splenocytes. The innate and adaptive immune responses were measured in mice immunized as described above. The results showed that ginsenoside Rg1 had adjuvant properties in stimulating IgG, splenocyte proliferation, and mRNA expression of cytokines IFN-γ and IL-4, as well as the expression of cell surface marker TLR4 in the HBsAg-immunized mice. These results indicate that Rg1 enhances both Th1 (IgG2b and IFN-γ) and Th2 (IgG1 and IL-4) responses. In addition, the TLR4 signaling pathway is involved in the adjuvant activities of ginsenoside Rg1.

Panax notoginseng saponins attenuate cardiomyocyte apoptosis through mitochondrial pathway in natural aging rats

Panax notoginseng saponins (PNS) have been widely used in the cardiovascular system for the treatment of cardiovascular diseases and stroke in China. In this study, we investigated the anti‐apoptotic effect of PNS on cardiomyocytes in the natural aging rat and explored the potential mechanisms regarding oxidative stress and mitochondrial function signaling pathways. Male Sprague–Dawley rats were randomly divided into five groups: adult control (3‐month old), aging control (24‐month old), and different doses of PNS‐treated aging rat groups (10, 30, 60 mg/kg/day, orally). After treatment of PNS or saline for 6 months, the effects of PNS on the cardiomyocytes were evaluated. Results showed that PNS significantly improved the morphological changes in myocardium, prevented the increase of cardiomyocyte apoptosis in the aging rats, and improved mitochondrial dysfunction associated aging in a dose‐dependent manner. PNS also significantly reversed the down‐regulation of FoxO3a and Mn‐SOD and up‐regulated PGC‐1α, LC3β, and Beclin‐1 levels. Our data demonstrated that during aging, mitochondrial dysfunction caused an increase of oxidative damage, which played a key role in cardiomyocyte apoptosis. PNS exerted an anti‐apoptotic effect via attenuating oxidative damage through oxidative stress‐ and mitochondrial function‐related signaling pathways.