Fenghua Fu

Cardioprotective effects of salvianolic Acid a on myocardial ischemia-reperfusion injury in vivo and in vitro.

Salvianolic acid A (SAA), one of the major active components of Danshen that is a traditional Chinese medicine, has been reported to possess protective effect in cardiac diseases and antioxidative activity. This study aims to investigate the cardioprotection of SAA in vivo and in vitro using the model of myocardial ischemia-reperfusion in rat and hydrogen peroxide (H2O2)-induced H9c2 rat cardiomyoblasts apoptosis. It was found that SAA significantly limited infarct size of ischemic myocardium when given immediately prior to reperfusion. SAA also significantly suppressed cellular injury and apoptotic cell death. Additionally, the results of western blot and phospho-specific antibody microarray analysis showed that SAA could up-regulate Bcl-2 expression and increase the phosphorylation of proteins such as Akt, p42/p44 extracellular signal-related kinases (Erk1/2), and their related effectors. The phosphorylation of those points was related to suppress apoptosis. In summary, SAA possesses marked protective effect on myocardial ischemia-reperfusion injury, which is related to its ability to reduce myocardial cell apoptosis and damage induced by oxidative stress. The protection is achieved via up-regulation of Bcl-2 expression and affecting protein phosphorylation. These findings indicate that SAA may be of value in cardioprotection during myocardial ischemia-reperfusion injury, which provide pharmacological evidence for clinical application.

Danshensu ameliorates the cognitive decline in streptozotocin-induced diabetic mice by attenuating advanced glycation end product-mediated neuroinflammation

Spatial learning and memory are impaired in diabetic animals. The interaction of advanced glycation end products (AGEs) with the receptor of AGEs (RAGE), resulting in the activation of nuclear factor-κB (NF-κB), plays an important role in pathways leading to the cytotoxic effects to neurons. Danshensu, a compound from Salvia miltiorrhiza Bunge, has neuroprotective effects. This study aimed to investigate the role of AGE-mediated neuroinflammation in learning and memory deficits and the effect of Danshensu on the cognitive decline in diabetic mice. C57BL/6 mice were injected intraperitoneally with streptozotocin. Sodium Danshensu (sodium salt of Danshensu) was administered at a dose of 15, 30, or 60 mg/kg for 12 weeks. The results showed that diabetes caused impairment in acquisition and retrieval processes, as demonstrated by performance in the Morris water maze test. Danshensu not only reduced the mean escape latency but also increased the percentage of time spent in the target quadrant. Western blot analysis revealed that there was a significant increase in the expression of RAGE, p-p38, and COX-2, and the NF-κB activation. Danshensu partly blocked the expression of RAGE, p-p38, and COX-2, and NF-κB activation, and inhibited the increase of TNF-α, IL-6, and PGE₂. However, Danshensu did not affect body weight and the levels of blood glucose, glycosylated hemoglobin, insulin, and AGEs. These findings demonstrate that AGE-mediated neuroinflammation plays an important role in learning and memory deficits in diabetic mice and that Danshensu may provide a potential alternative for the prevention of cognitive impairment associated with diabetes by attenuating AGE-mediated neuroinflammation.

Cardioprotective Effects of 20(S)-Ginsenoside Rh2 against Doxorubicin-Induced Cardiotoxicity In Vitro and In Vivo

Doxorubicin (DOX) is considered as one of the best antineoplastic agents. However, its clinical use is restricted by its associated cardiotoxicity, which is mediated by the production of reactive oxygen species. In this study, 20(S)-ginsenoside Rh2 (Rh2) was explored whether it had protective effects against DOX-induced cardiotoxicity. In vitro study on H9C2 cell line, as well as in vivo investigation in one mouse and one rat model of DOX-induced cardiomyopathy, was carried out. The results showed that pretreatment with Rh2 significantly increased the viability of DOX-injured H9C2 cells. In the mouse model, Rh2 could suppress the DOX-induced release of the cardiac enzymes into serum and improved the occurred pathological changes through ameliorating the decreased antioxidant biomolecules and the cumulated lipid peroxidation malondialdehyde in heart tissues. In the rat model, Rh2 could attenuate the change of ECG resulting from DOX administration. Furthermore, Rh2 enhanced the antitumor activity of DOX in A549 cells. Our findings thus demonstrated that Rh2 pretreatment could effectively alleviate heart injury induced by DOX, and Rh2 might act as a novel protective agent in the clinical usefulness of DOX.

Escin attenuates acute lung injury induced by endotoxin in mice

Endotoxin causes multiple organ dysfunctions, including acute lung injury (ALI). The current therapeutic strategies for endotoxemia are designed to neutralize one or more of the inflammatory mediators. Accumulating experimental evidence suggests that escin exerts anti-inflammatory and anti-edematous effects. The aim of this study was to evaluate the effect of escin on ALI induced by endotoxin in mice. ALI was induced by injection of lipopolysaccharide (LPS) intravenously. The mice were given dexamethasone or escin before injection of LPS. The mortality rate was recorded. Tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β) and nitric oxide (NO) were measured. Pulmonary superoxide dismutase (SOD), glutathione peroxidase (GPx) activity, glutathione (GSH), malondialdehyde (MDA) contents, and myeloperoxidase (MPO) activity were also determined. The expression of glucocorticoid receptor (GR) level was detected by Western blotting. Pretreatment with escin could decrease the mortality rate, attenuate lung injury resulted from LPS, down-regulate the level of the inflammation mediators, including NO, TNF-α, and IL-1β, enhance the endogenous antioxidant capacity, and up-regulating the GR expression in lung. The results suggest that escin may have potent protective effect on the LPS-induced ALI by inhibiting of the inflammatory response, and its mechanism involves in up-regulating the GR and enhancing the endogenous antioxidant capacity.

The Role of P-Glycoprotein in Transport of Danshensu across the Blood-Brain Barrier

Danshensu (3-(3, 4-dihydroxyphenyl) lactic acid), a water-soluble active component isolated from the root of Salvia miltiorrhiza Bunge, is widely used for the treatment of cerebrovascular diseases. The present study aims to investigate the role of P-glycoprotein in transport of Danshensu across the blood-brain barrier. Sprague-Dawley rats were pretreated with verapamil at a dose of 20u2009mgu2009kg−1 (verapamil group) or the same volume of normal saline (control group). Ninety minutes later, the animals were administrated with Danshensu (15u2009mg kg−1) by intravenous injection. At 15 min, 30u2009min, and 60u2009min after Danshensu administration, the levels of Danshensu in the blood and brain were detected by high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The results showed that Danshensu concentrations in the brain of the rats pretreated with verapamil were significantly increased. In addition, the brain-plasma ratios of the group pretreated with verapamil were much higher than that of the control group. There was no difference in Danshensu level in plasma between the verapamil group and control group. The findings indicated that Danshensu can pass the blood-brain barrier, and P-glycoprotein plays an important role in Danshensu transportation in brain.

Ginsenoside Rg1 exerts synergistic anti-inflammatory effects with low doses of glucocorticoids in vitro

Glucocorticoids (GCs) are usually used to treat inflammatory diseases. However, they cause severe and irreversible side effects, which limit the use of these compounds. Ginsenoside Rg1 had been demonstrated to possess anti-inflammatory and anti-cancer effects. The present study was designed to investigate whether Rg1 exhibits synergistic anti-inflammatory effects when combined with glucocorticoids. After stimulated by lipopolysaccharide (LPS), murine macrophagic RAW264.7 cells were treated with Rg1, corticosterone (Cort) or Rg1 and Cort. Then nitric oxide (NO), tumor necrosis factor-α (TNF-α) and glucocorticoid receptor (GR) expression were measured. The results showed that Rg1 or Cort could reduce the production of NO and TNF-α, and Rg1 dose-dependently up-regulated GR expression, while Cort dose-dependently down-regulated GR expression. The combination of low concentrations of Rg1 with Cort, which alone could not markedly inhibit the release of inflammatory factors, inhibited the secretion of NO and TNF-α in LPS-stimulated RAW264.7 macrophage cells, and up-regulated the expression of GR. The findings suggested Rg1 can synergize with glucocorticoid to enhance its anti-inflammatory effect.

Ocotillol Enhanced the Antitumor Activity of Doxorubicin via p53-Dependent Apoptosis

The use of doxorubicin (Dox) was severely constrained by dose-dependent side effects, which might be attenuated by combining a “sensitizer” to decrease its cumulative dosage. In this study, it was investigated whether ocotillol could enhance the antiproliferation activity of Dox. MTT assays and xenograft tumor model were firstly conducted to evaluate the effect of ocotillol on the antitumor activity of Dox. Flow cytometry and Hoechst staining assays were then performed to assess cell apoptosis. Western blot and real-time PCR were finally used to detect the expression of p53 and its target genes. Our results showed ocotillol to enhance Dox-induced cell death in p53 wild-type cancer cells. Compared with Dox alone, Dox with ocotillol (Dox-O) could induce much more cell apoptosis and activate p53 to a much greater degree, which in turn markedly increased expression of proapoptosis genes. The enhanced cytotoxic activity was partially blocked by pifithrin-α, which might be through attenuating the increased apoptosis. Furthermore, ocotillol significantly increased the antitumor activity of Dox in A549 xenograft tumor in nude mice. These findings indicated that ocotillol could potentiate the cytotoxic effect of Dox through p53-dependent apoptosis and suggested that coadministration of ocotillol with Dox might be a potential therapeutic strategy.

Down-regulation of P-glycoprotein expression contributes to an increase in Danshensu accumulation in the cerebral ischemia/reperfusion brain

P-glycoprotein (P-gp) plays a key role in the distribution and elimination of many clinically important therapeutic substances. P-gp inhibition is capable of increasing the concentration of various drugs in the brain. Danshensu is a main hydrophilic constituent of Salvia miltiorrhiza Bunge which is used traditionally to treat cerebrovascular diseases. In the present study, the effects of cerebral ischemia/reperfusion on the transport of Danshensu in the brain were observed by assaying the concentration at 15, 30 and 60 min after cerebral ischemia/reperfusion in the brain of rats. Furthermore, the expression of P-gp in the brain was also measured. Results showed that Danshensu concentrations in the ischemic hemisphere significantly increased compared to those in the non-ischemic hemisphere and the brain of the sham group. P-gp expression was inhibited by cerebral ischemia/reperfusion to some extent, and down-regulated much more by Danshensu treatment. The findings indicate that the down-regulation of P-gp expression induced by both cerebral ischemia/reperfusion and Danshensu treatment contributes to the increase of Danshensu accumulation in the brain.

Anti-inflammatory effects of escin are correlated with the glucocorticoid receptor/NF-κB signaling pathway, but not the COX/PGF2α signaling pathway

In China, escin has been widely used in the clinic as a potent anti-inflammatory drug. Previous studies have indicated that escin exerts its anti-inflammatory effect by enhancing the release of glucocorticoids (GCs) and prostaglandin-F2α (PGF2α), and this has been documented in the drug description. However, our previous studies demonstrated that escin did not increase the secretion of GCs, but instead elevated the protein expression of the GC receptor (GR), which may have repressed nuclear factor (NF)-κB-mediated gene expression. The aim of this study was to determine the functions of NF-κB and PGF2α with regard to the anti-inflammatory effect of escin. We investigated the anti-inflammatory effects of dexamethasone, diclofenac and escin against carrageenan-induced paw edema in rats, and observed that escin exerted a GC-like anti-inflammatory effect. In addition, we studied the role of PGF2α in the anti-inflammatory effect exerted by escin in an acetic acid-induced capillary permeability model in mice. The results revealed that the coadministration of escin and diclofenac, a potent prostaglandin-synthesis inhibitor, did not affect the anti-inflammatory effect of escin. Furthermore, we investigated the function of NF-κB with regard to the anti-inflammatory effect exerted by escin in lipopolysaccharide (LPS)-treated mice, and demonstrated that escin significantly inhibited the expression of NF-κB. These results suggest that escin has a GC-like anti-inflammatory effect, and that its mechanisms may be correlated with the GC receptor/NF-κB signaling pathway, but not the COX/PGF2α signaling pathway.

Oral Administration of Escin Inhibits Acute Inflammation and Reduces Intestinal Mucosal Injury in Animal Models

The present study aimed to investigate the effects of oral administration of escin on acute inflammation and intestinal mucosal injury in animal models. The effects of escin on carrageenan-induced paw edema in a rat model of acute inflammation, cecal ligation and puncture (CLP) induced intestinal mucosal injury in a mouse model, were observed. It was shown that oral administration of escin inhibits carrageenan-induced paw edema and decreases the production of prostaglandin E2 (PGE2) and cyclooxygenase- (COX-) 2. In CLP model, low dose of escin ameliorates endotoxin induced liver injury and intestinal mucosal injury and increases the expression of tight junction protein claudin-5 in mice. These findings suggest that escin effectively inhibits acute inflammation and reduces intestinal mucosal injury in animal models.