Anti-Inflammatory Effects of a Cordyceps sinensis Mycelium Culture Extract (Cs-4) on Rodent Models of Allergic Rhinitis and Asthma.

Allergic rhinitis and asthma are common chronic allergic diseases of the respiratory tract, which are accompanied by immunoglobulin E (IgE)-mediated inflammation and the involvement of type 2 T helper cells, mast cells, and eosinophils. Cordyceps sinensis (Berk.) Sacc is a fungal parasite on the larva of Lepidoptera. It has been considered to be a health-promoting food and, also, one of the best-known herbal remedies for the treatment of airway diseases, such as asthma and lung inflammation. In the present study, we demonstrated the antiallergic rhinitis effect of Cs-4, a water extract prepared from the mycelium culture of Cordyceps sinensis (Berk) Sacc, on ovalbumin (OVA)-induced allergic rhinitis in mice and the anti-asthmatic effect of Cs-4 in a rat model of asthma. Treatment with Cs-4 suppressed the nasal symptoms induced in OVA-sensitized and challenged mice. The inhibition was associated with a reduction in IgE/OVA-IgE and interleukin (IL)-4/IL-13 levels in the nasal fluid. Cs-4 treatment also decreased airway responsiveness and ameliorated the scratching behavior in capsaicin-challenged rats. It also reduced plasma IgE levels, as well as IgE and eosinophil peroxidase levels, in the bronchoalveolar fluid. Cs-4 treatment completely suppressed the increases in IL-4, IL-5, and IL-13 levels in rat lung tissue. In conclusion, our results suggest that Cs-4 has the potential to alleviate immune hypersensitivity reactions in allergic rhinitis and asthma.

48Biochemical mechanisms of the anti-obesity effect of a triterpenoid-enriched extract of Cynomorium songaricum in mice with high-fat-diet-induced obesity.

BACKGROUND: HCY2, a triterpenoid-enriched extract of Cynomorii Herba, has been shown to reduce body weight and adiposity and attenuate manifestations of the associated metabolic syndrome in high-fat-diet (HFD)-fed mice. PURPOSE: The current study aimed to investigate the biochemical mechanism underlying the anti-obesity effect produced by HCY2. STUDY DESIGN: An HCY2-containing extract was examined for its effects on the regulation of adenosine monophosphate-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor gamma co-activator-1 (PGC1) pathways and the protein expression related to mitochondrial uncoupling and biogenesis in skeletal muscle using an HFD-induced obese mouse model. METHODS: The obese mouse model was produced by providing HFD (60% kcal from fat) ad libitum. The effects and signaling mechanisms of HCY2 were examined using analytical procedures which included enzyme-linked immunosorbent assay kits, Western blot analysis, and the use of a Clark-type oxygen electrode. RESULTS: The current study revealed that the weight reduction produced by HCY2 is associated with the activation of the AMPK signaling pathway, with resultant increases in mitochondrial biogenesis and expression of uncoupling protein 3 in skeletal muscle in vivo. The use of a recoupler, ketocholestanol, delineated the precise role of mitochondrial uncoupling in the anti-obesity effect afforded by HCY2 in obese mice. CONCLUSION: Our experimental findings offer a promising prospect for the use of HCY2 in the management of obesity through the regulation of AMPK/PGC1 pathways.

A Chinese Herbal Formulation, Xiao-Er-An-Shen Decoction, Attenuates Tourette Syndrome, Possibly by Reversing Abnormal Changes in Neurotransmitter Levels and Enhancing Antioxidant Status in Mouse Brain.

Xiao-Er-An-Shen Decoction (XEASD) has been used clinically for the treatment of Tourette syndrome (TS) in children for more than 20 years in mainland China. The biochemical mechanism underlying the therapeutic action produced by XEASD treatment against TS remains unknown. However, a previous study has shown that pre-incubation of PC12 neuronal cells with XEASD can induce neurite outgrowth and protect against oxidative stress. In the present study, using a mouse model of TS induced by 3,3'-iminodipropionitrile (IDPN), stereotypy scoring, and locomotor activity were assessed. Levels of neurotransmitters including glutamate, aspartate, and gamma-aminobutyric acid (GABA) in brain tissue as well as plasma cyclic adenosine monophosphate (cAMP) were measured using assay kits. The ratio of reduced glutathione (GSH)/oxidized glutathione (GSSG) and Mn-superoxide dismutase (MnSOD) activity in brain mitochondrial fractions as well as mitochondrial glutathione reductase and cytosolic γ-glutamylcysteine activities were also examined. The phosphorylation of cAMP-responsive element binding protein (CREB) in brain tissue was measured by Western blot analysis. XEASD treatment was found to significantly ameliorate the severity of behavioral symptoms in affected mice, as evidenced by decreases in the stereotypy score and locomotor activity. The beneficial effect of XEASD was accompanied by the reversal of abnormal levels of GABA, glutamate, and aspartate, in brain tissue of IDPN-challenged mice. In addition, XEASD treatment increased plasma cyclic adenosine monophosphate (cAMP) levels and activated the phosphorylation of CREB in brain tissue of TS mice. Furthermore, XEASD treatment was found to enhance the antioxidant status of brain tissue in affected mice, as evidenced by increases in the GSH/GSSG ratio and the activity of MnSOD in brain mitochondrial fractions. Taken together, these experimental results will hopefully provide insight into the pharmacological basis for the beneficial effects of XEASD in children suffering from TS.

Ursolic acid induces mitochondrial biogenesis through the activation of AMPK and PGC-1 in C2C12 myotubes: a possible mechanism underlying its beneficial effect on exercise endurance.

Mitochondrial biogenesis, which involves an increase in mitochondrial number and the overall capacity of oxidative phosphorylation, is a critical determinant of skeletal muscle function. Recent findings have shown that some natural products can enhance mitochondrial adaptation to aerobic exercise, which in turn improves exercise performance, presumably by delaying muscle fatigue. Ursolic acid (UA), a natural triterpene, is commonly found in various vegetables and fruits. In the current study, UA was shown to increase mitochondrial mass and ATP generation capacity, with a concomitant production of a low level of mitochondrial reactive oxygen species (ROS) in C2C12 myotubes. Mitochondrial ROS, in turn, activated the redox sensitive adenosine monophosphate-dependent protein kinase (AMPK)/peroxisome proliferator-activated receptor γ coactivator-1(PGC-1) pathway. The activation of AMPK/PGC-1 further increased the expression of cytochrome c oxidase (COX) and uncoupling protein 3. Animal studies showed that UA can also dose-dependently increase the endurance exercise capacity in mice, as assessed by a weight-loaded swimming test and a hanging wire test. Our findings suggest that UA may induce mitochondrial biogenesis through the activation of AMPK and PGC-1 pathways in skeletal muscle, thereby offering a promising prospect for its use to enhance exercise endurance and alleviating fatigue in humans.

Acute Pre-/Post-Treatment with 8th Day SOD-Like Supreme (a Free Radical Scavenging Health Product) Protects against Oxidant-Induced Injury in Cultured Cardiomyocytes and Hepatocytes In Vitro as Well as in Mouse Myocardium and Liver In Vivo.

8th Day superoxide dismutase (SOD)-Like Supreme (SOD-Like Supreme, a free radical scavenging health product) is an antioxidant-enriched fermentation preparation with free radical scavenging properties. In the present study, the cellular/tissue protective actions of SOD-Like Supreme against menadione toxicity in cultured H9c2 cardiomyocytes and in AML12 hepatocytes as well as oxidant-induced injury in the mouse myocardium and liver were investigated. SOD-Like Supreme was found to possess potent free radical scavenging activity in vitro as assessed by an oxygen radical absorbance capacity assay. Incubation with SOD-Like Supreme (0.5-3% (v/v)) was shown to protect against menadione-induced toxicity in H9c2 and AML12 cells, as evidenced by increases in cell viability. The ability of SOD-Like Supreme to protect against menadione cytotoxicity was associated with an elevation in the cellular reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio in menadione-challenged cells. Consistent with the cell-based studies, pre-/post-treatment with SOD-Like Supreme (0.69 and 2.06 mL/kg, three intermittent doses per day for two consecutive days) was found to protect against isoproterenol-induced myocardial injury and carbon tetrachloride hepatotoxicity in mice. The cardio/hepatoprotection afforded by SOD-Like Supreme was also paralleled by increases in myocardial/hepatic mitochondrial GSH/GSSG ratios in the SOD-Like Supreme-treated/oxidant-challenged mice. In conclusion, incubation/treatment with SOD-Like Supreme was found to protect against oxidant-induced injury in vitro and in vivo, presumably by virtue of its free radical scavenging activity.

Differential Action between Schisandrin A and Schisandrin B in Eliciting an Anti-Inflammatory Action: The Depletion of Reduced Glutathione and the Induction of an Antioxidant Response.

Schisandrin A (Sch A) and schisandrin B (Sch B) are active components of Schisandrae Fructus. We compared the biochemical mechanism underlying the anti-inflammatory action of Sch A and Sch B, using cultured lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and concanavalin (ConA)-stimulated mouse splenocytes. Pre-incubation with Sch A or Sch B produced an anti-inflammatory action in LPS-stimulated RAW264.7 cells, as evidenced by the inhibition of the pro-inflammatory c-Jun N-terminal kinases/p38 kinase/nuclear factor-κB signaling pathway as well as the suppression of various pro-inflammatory cytokines and effectors, with the extent of inhibition by Sch A being more pronounced. The greater activity of Sch A in anti-inflammatory response was associated with a greater decrease in cellular reduced glutathione (GSH) level and a greater increase in glutathione S-transferase activity than corresponding changes produced by Sch B. However, upon incubation, only Sch B resulted in the activation of the nuclear factor (erythroid-derived 2)-like factor 2 and the induction of a significant increase in the expression of thioredoxin (TRX) in RAW264.7 cells. The Sch B-induced increase in TRX expression was associated with the suppression of pro-inflammatory cytokines and effectors in LPS-stimulated macrophages. Studies in a mouse model of inflammation (carrageenan-induced paw edema) indicated that while long-term treatment with either Sch A or Sch B suppressed the extent of paw edema, only acute treatment with Sch A produced a significant degree of inhibition on the inflammatory response. Although only Sch A decreased the cellular GSH level and suppressed the release of pro-inflammatory cytokines and cell proliferation in ConA-simulated splenocytes in vitro, both Sch A and Sch B treatments, while not altering cellular GSH levels, suppressed ConA-stimulated splenocyte proliferation ex vivo. These results suggest that Sch A and Sch B may act differentially on activating GST/ depleting cellular GSH and inducing an antioxidant response involved in their anti-inflammatory actions.

A Cistanches Herba Fraction/ ß -Sitosterol Causes a Redox-Sensitive Induction of Mitochondrial Uncoupling and Activation of Adenosine Monophosphate-Dependent Protein Kinase/Peroxisome Proliferator-Activated Receptor γ Coactivator-1 in C2C12 Myotubes: A Possible Mechanism Underlying the Weight Reduction Effect.

Previous studies have demonstrated that HCF1, a semipurified fraction of Cistanches Herba, causes weight reduction in normal diet- and high fat diet-fed mice. The weight reduction was associated with the induction of mitochondrial uncoupling and changes in metabolic enzyme activities in mouse skeletal muscle. To further investigate the biochemical mechanism underlying the HCF1-induced weight reduction, the effect of HCF1 and its active component, ß-sitosterol (BSS), on C2C12 myotubes was examined. Incubation with HCF1/BSS caused a transient increase in mitochondrial membrane potential (MMP), possibly by fluidizing the mitochondrial inner membrane. The increase in MMP was paralleled to an increase in mitochondrial reactive oxygen species (ROS) production. Mitochondrial ROS, in turn, triggered a redox-sensitive induction of mitochondrial uncoupling by uncoupling protein 3 (UCP3). Biochemical analysis indicated that HCF1 was capable of activating an adenosine monophosphate-dependent protein kinase/peroxisome proliferator-activated receptor γ coactivator-1 pathway and thereby increased the expression of cytochrome c oxidase and UCP3. Animal studies using mitochondrial recoupler also confirmed the role of mitochondrial uncoupling in the HCF1-induced weight reduction. In conclusion, a HCF1/BSS causes the redox-sensitive induction of mitochondrial uncoupling and activation of AMPK/PGC-1 in C2C12 myotubes, with resultant reductions in body weight and adiposity by increased energy consumption.

ß-sitosterol protects against carbon tetrachloride hepatotoxicity but not gentamicin nephrotoxicity in rats via the induction of mitochondrial glutathione redox cycling.

Previous findings have demonstrated that ß-sitosterol (BSS), an active component of Cistanches Herba, protected against oxidant injury in H9c2 cardiomyocytes and in rat hearts by enhancing mitochondrial glutathione redox cycling, possibly through the intermediacy of mitochondrial reactive oxygen species production. We therefore hypothesized that BSS pretreatment can also confer tissue protection against oxidant injury in other vital organs such as liver and kidney of rats. In this study, the effects of BSS pretreatment on rat models of carbon tetrachloride (CCl4) hepatotoxicity and gentamicin nephrotoxicity were investigated. The findings showed that BSS pretreatment protected against CCl4-induced hepatotoxicity, but not gentamicin nephrotoxicity in rats. The hepatoprotection afforded by BSS was associated with the improvement in mitochondrial glutathione redox status, presumably through the glutathione reductase-mediated enhancement in mitochondrial glutathione redox cycling. The hepatoprotection afforded by BSS was also accompanied by the improved mitochondrial functional ability in rat livers. The inability of BSS to protect against gentamicin nephrotoxicity was likely due to the relatively low bioavailability of BSS in rat kidneys. BSS may serve as potential mitohormetic agent for the prevention of oxidative stress-induced injury in livers.

New insights into the chemical and biochemical basis of the "yang-invigorating" action of chinese yang-tonic herbs.

In the practice of traditional Chinese medicine, many Yang-tonic herbs have been used for retarding the decline in bodily function and delaying the onset of age-related diseases. Our earlier studies have demonstrated that Yang-invigorating herbs/formulations protect against oxidative injury in various organs and also extend the median lifespan in mice. This lifespan extension was associated with an upregulation of cellular antioxidant status including that of mitochondria whose functional capacity is also increased by "Yang-invigorating" herbs/formulations. In this paper, we propose that triterpenes and phytosterols, which are ubiquitously found in Yang-tonic herbs, may be the chemical entities responsible for enhancing mitochondrial functional and antioxidant capacity and thus the "Yang-invigorating" action. The biochemical mechanism underlying this "Yang-invigorating" action may involve a sustained production of low levels of mitochondrial reactive oxygen species (ROS) secondary to an increased activity of the electron transport chain, with the possible involvement of mitochondrial uncoupling. The increase in mitochondrial functional capacity can retard the decline in bodily function during aging, whereas the mitochondrial ROS production is instrumental in eliciting a glutathione antioxidant response via redox-sensitive signaling pathways, which can delay the onset of age-related diseases.

Long-term treatment with a health product (Squina Diacylglyceryl Ether) enhances innate and adaptive immunity in mice.

This study aimed to investigate the effects of a health product Squina (Diacylglyceryl Ether) (DAGE) on innate and adaptive immunity in mice. Both ex vivo/ in vivo mouse models and an in vitro system using cultured mouse splenocytes were recruited for the assessment of innate and adaptive immunity. For the innate immune response, DAGE extract treatment enhanced the LPS-induced IL1-ß secretion by activated macrophages in vitro and long-term DAGE treatment (0.18 and 1.8 g/kg × 20 doses) elevated the phagocytic activity of macrophages, as well as natural killer cell activity in mice. The DAGE-induced increase in macrophage phagocytic and natural killer cell activities were accompanied by the suppression of tumor growth in Sarcoma-180 cell-inoculated mice. For the adaptive immune response, long-term DAGE treatment enhanced the splenocyte index and concanavalin A- stimulated proliferation ex vivo in mice. Consistently, the incubation with DAGE extract potentiated the concanavalin A-stimulated proliferation in mouse splenocytes in vitro. In conclusion, the results show that long-term DAGE treatment produces stimulatory effects on both innate and adaptive immunity in mice.

Neuroprotection against oxidative injury by a nucleic acid-based health product (Squina DNA) through enhancing mitochondrial antioxidant status and functional capacity.

High levels of reactive oxygen species inflict oxidative damage on various cellular components that eventually culminate in a variety of diseases. This study investigated the cytoprotective effects of a nucleic acid-based health product (Squina [Hong Kong, China] DNA) against oxidative stress, particularly in neuronal cells. Adult female Sprague-Dawley rats were treated with Squina DNA, and changes in mitochondrial antioxidant status and functional capacity were assessed by the activities of antioxidant enzymes and ATP generation capacity in brain, heart ventricular, kidney, skeletal muscle, and liver tissues of control and Squina DNA-treated rats. The effects of Squina DNA pretreatment on brain/neuronal cell injury were investigated in a rat model of cerebral ischemia/reperfusion (I/R) injury and a neuroblastoma SH-SY5Y cell model of ß-amyloid (Aß) protein fragment 25-35-induced toxicity. Long-term Squina DNA treatment caused dose-dependent increases in mitochondrial antioxidant status and functional capacity in rat brain, heart ventricular, kidney, skeletal muscle, and liver tissues. Squina DNA pretreatment significantly prevented I/R injury in brain tissue. The cerebroprotection was associated with a reversal of I/R-induced impairment in mitochondrial antioxidant status and disruption in membrane integrity. Squina DNA ethanol extract also significantly inhibited the Aß-induced apoptosis in SH-SY5Y neuronal cells, as evidenced by less caspase 3 and caspase 9 activation as well as mitochondrial cytochrome c release in Aß-challenged cells. Squina DNA may enhance the resistance of tissues and cells to oxidative stress, particularly in pathological conditions such as stroke and aging-related neurodegenerative diseases.

Cytochrome P-450-catalyzed reactive oxygen species production mediates the (-)schisandrin B-induced glutathione and heat shock responses in H9c2 cardiomyocytes.

OBJECTIVE: Schisandrin B (Sch B) is the most abundant, active dibenzocyclooctadiene derivative isolated from the fruit of Schisandra chinensis (Turcz) Baillon (Schisandraceae). (-)Sch B was found to be the most potent stereoisomer of Sch B in producing cytoprotective action in H9c2 cardiomyocytes. The elucidation of biochemical mechanism underlying the cytoprotection of (-)Sch B has attracted much interest in the area of preventive medicine. Here, we examined whether the (-)Sch B-induced enhancement of glutathione antioxidant and heat shock responses and the associated cytoprotection against hypoxia/reoxygenation-induced apoptosis are mediated by reactive oxygen species (ROS) arising from cytochrome P-450 (CYP)-catalyzed metabolism of (-)Sch B in H9c2 cardiomyocytes. MATERIALS AND METHODS: The effects of CYP inhibitor (1-aminobenzotriazole, ABT) and antioxidant (dimethylthiouracil, DMTU) on (-)Sch B-induced ROS production and associated increases in cellular-reduced glutathione (GSH) level as well as heat shock protein (Hsp) 25/70 production were investigated in H9c2 cardiomyocytes. The (-)Sch B-induced ROS generation was monitored with or without ABT/DMTU for 6 h in situ, while (-)Sch B-induced cellular GSH level and Hsp 25/70 production, as well as cytoprotection were measured at 16 h post-(-)Sch B exposure. RESULTS: The results indicated that (-)Sch B caused a dose-dependent increase in ROS production in H9c2 cardiomyocytes, which was completely suppressed by pre- and co-treatment with ABT or DTMU. The incubation with (-)Sch B for 6 h caused dose-dependent increases in cellular GSH level and Hsp 25/70 production, as well as protection against hypoxia/reoxygenation-induced apoptosis at 16-h post-drug exposure in H9c2 cardiomyocytes. All these cellular responses were abrogated by treatment with ABT or DMTU. CONCLUSION: The results suggest that ROS arising from the CYP-catalyzed metabolism of (-)Sch B elicit glutathione antioxidant and heat shock responses, thereby protecting against oxidant-induced apoptosis in H9c2 cardiomyocytes.

Danshen-Gegen decoction protects against hypoxia/reoxygenation-induced apoptosis by inhibiting mitochondrial permeability transition via the redox-sensitive ERK/Nrf2 and PKCε/mKATP pathways in H9c2 cardiomyocytes.

Danshen-Gegen (DG) Decoction, an herbal formulation containing Radix Salviae miltiorrhizae and Radix Puerariae lobatae, has been used for the treatment of coronary artery disease in Chinese medicine. In the present study, the involvement of ERK- and PKCε-mediated pathways in the cytoprotection against apoptosis afforded by DG pretreatment was investigated in H9c2 cardiomyocytes. Pretreatment with a methanol extract of aqueous DG decoction protected against hypoxia/reoxygenation-induced apoptosis in H9c2 cardiomyocytes. The cytoprotection was associated the enhancement of cellular reduced glutathione and a reduced sensitivity to Ca(2+)-induced mitochondrial permeability transition. DG extract increased the production of cytochrome P-450 (CYP)-dependent reactive oxygen species (ROS) in H9c2 cardiomyocytes, which was accompanied by the concomitant activation of ERK1/2 and PKCε. The DG-induced ERK1/2 activation was followed by the translocation of Nrf2 from the cytosol to the mitochondria accompanied by an increase in the expression of glutathione-related antioxidant proteins. In addition, the increased expression of hemeoxygenase-1 was associated with the activation of Akt and BAD, indicative of anti-apoptotic activity. In conclusion, DG treatment activated both ERK/Nrf2 and PKCε pathways, presumably by ROS arising from CYP-catalyzed processes, with resultant inhibition of hypoxia/reoxygenation-induced apoptosis immediately after DG treatment or even after an extended time interval following DG treatment.

Cytochrome P450-catalysed reactive oxygen species production mediates the (-)schisandrin B-induced glutathione and heat shock responses in AML12 hepatocytes.

Sch B (schisandrin B), the most abundant dibenzocyclooctadiene lignan in Fructus schisandrae, can induce glutathione antioxidant and heat shock responses, as well as protect against oxidant-induced injury in various tissues, including the liver in rodents and AML12 (alpha mouse liver 12) hepatocytes. (-)Sch B is the most potent stereoisomer of Sch B in its cytoprotective action on AML12 hepatocytes. To define the role of ROS (reactive oxygen species) arising from CYP (cytochrome P450)-catalysed metabolism of (-)Sch B in triggering glutathione antioxidant and heat shock responses, the effects of a CYP inhibitor [ABT (aminobenzotriazole)] and antioxidants [DMTU (dimethylthiouracil) and TRX (trolox)] on (-)Sch B-induced ROS production and associated increases in cellular GSH level, as well as Hsp25/70 (heat-shock protein 25/70) production, were investigated in AML12 hepatocytes. The results indicated that (-)Sch B causes a dose dependent and sustained increase in ROS production over 6 h in AML12 hepatocytes, which was completely suppressed by pre-/co-treatment with ABT or DTMU/TRX. Incubation with (-)Sch B for 6 h caused optimal and dose-dependent increases in cellular GSH level and Hsp25/70 production at 16 h post-drug exposure in AML12 hepatocytes. These cellular responses were associated with protection against menadione-induced apoptosis. Pre-/co-treatment with ABT or antioxidants completely abrogated the (-)Sch B-induced glutathione antioxidant and heat shock responses, as well as protection against menadione-induced apoptosis. Experimental evidence obtained thus far supports the causal role of ROS arising from the CYP-catalysed metabolism of (-)Sch B in eliciting glutathione antioxidant and heat shock responses in AML12 hepatocytes.

Acute treatment with Danshen-Gegen decoction protects the myocardium against ischemia/reperfusion injury via the redox-sensitive PKCɛ/mK(ATP) pathway in rats.

Danshen-Gegen (DG) decoction, an herbal formulation comprising Radix Salvia Miltiorrhiza and Radix Puerariae Lobatae, is prescribed for the treatment of coronary heart disease in Chinese medicine. Experimental and clinical studies have demonstrated that DG decoction can reduce the extent of atherosclerosis. In the present study, using an ex vivo rat model of myocardial ischemia/reperfusion (I/R) injury, we investigated the myocardial preconditioning effect of an aqueous DG extract prepared from an optimized weight-to-weight ratio of Danshen and Gegen. Short-term treatment with DG extract at a daily dose of 1 g/kg and 2 g/kg for 3 days protected against myocardial I/R injury in rats. The cardioprotection afforded by DG pretreatment was paralleled by enhancements in mitochondrial antioxidant status and membrane structural integrity, as well as a decrease in the sensitivity of mitochondria to Ca²âº-stimulated permeability transition in vitro, particularly under I/R conditions. Short-term treatment with the DG extract also enhanced the translocation of PKCɛ from the cytosol to mitochondria in rat myocardium, and this translocation was inhibited by α-tocopherol co-treatment with DG extract in rats. Short-term DG treatment may precondition the myocardium via a redox-sensitive PKCɛ/mK(ATP) pathway, with resultant inhibition of the mitochondrial permeability transition through the opening of mitochondrial K(ATP) channels. Our results suggest that clinical studies examining the effectiveness of DG extract given prophylactically in affording protection against myocardial I/R injury would be warranted.

Myocardial post-conditioning with Danshen-Gegen decoction protects against isoproterenol-induced myocardial injury via a PKCε/mKATP-mediated pathway in rats.

BACKGROUND: Danshen-Gegen decoction (DG), a Chinese herbal formula, has been demonstrated to be effective for the treatment of coronary heart disease such as myocardial infarction. In the present study, we investigated the effect of DG post-conditioning on isoproterenol (ISO)-induced myocardial injury in rats. METHODS: ISO was injected intraperitoneally (200 mg/kg) to induce acute (2-6 hours) myocardial injury in adult female rats. DG (4 g/kg) was administered per oral immediately after the injection of ISO in the rats. Extent of myocardial injury was assessed by measurements of plasma enzyme activities. Myocardial mitochondrial glutathione antioxidant status, lipid peroxidation and mitochondrial calcium ion loading and cytochrome c release were also measured. Effects of inhibitors of protein kinase C-epsilon (PKCε) ranslocation and mitochondrial ATP-sensitive potassium channel (mKATP) on myocardial post-conditioning by DG were investigated. RESULTS: ISO inflicted acute myocardial injury in the rats as evidenced by increased plasma enzyme activities. DG post-treatment alleviated the ISO-induced acute myocardial injury. CONCLUSION: DG post-treatment protected the myocardium against ISO-induced acute injury in rats. The myocardial post-conditioning by DG is likely mediated by PKCε/mKATP signaling pathway.

Schisandrin B elicits a glutathione antioxidant response and protects against apoptosis via the redox-sensitive ERK/Nrf2 pathway in H9c2 cells.

This study investigated the signal transduction pathway involved in the cytoprotective action of (-)schisandrin B [(-)Sch B, a stereoisomer of Sch B]. Using H9c2 cells, the authors examined the effects of (-)Sch B on MAPK and Nrf2 activation, as well as the subsequent eliciting of glutathione response and protection against apoptosis. Pharmacological tools, such as cytochrome P-450 (CYP) inhibitor, antioxidant, MAPK inhibitor, and Nrf2 RNAi, were used to delineate the signaling pathway. (-)Sch B caused a time-dependent activation of MAPK in H9c2 cells, with the degree of ERK activation being much larger than that of p38 or JNK. The MAPK activation was followed by an increase in the level of nuclear Nrf2, an indirect measure of Nrf2 activation, and the eliciting of a glutathione antioxidant response. The activation of MAPK and Nrf2 seemed to involve oxidants generated from a CYP-catalyzed reaction with (-)Sch B. Both ERK inhibition by U0126 and Nrf2 suppression by Nrf2 RNAi transfection largely abolished the cytoprotection against hypoxia/reoxygenation-induced apoptosis in (-)Sch B-pretreated cells. (-)Sch B pretreatment potentiated the reoxygenation-induced ERK activation, whereas both p38 and JNK activations were suppressed. Under the condition of ERK inhibition, Sch B treatment did not protect against ischemia/reperfusion injury in an ex vivo rat heart model. The results indicate that (-)Sch B triggers a redox-sensitive ERK/Nrf2 signaling, which then elicits a cellular glutathione antioxidant response and protects against hypoxia/reoxygenation-induced apoptosis in H9c2 cells. The ERK-mediated signaling is also likely involved in the cardioprotection afforded by Sch B in vivo.

Co-treatment with Shengmai San-derived herbal product ameliorates chronic ethanol-induced liver damage in rats.

Wei Kang Su (WKS) is an antioxidant-enriched herbal product manufactured on the basis of Shengmai San, a well-known traditional Chinese herbal formula. In the present study, we investigated the effects of WKS co-treatment on chronic ethanol toxicity in rats. WKS co-treatment protected against chronic ethanol-induced hepatotoxicity, as evidenced by the suppression of plasma enzyme activities and reactive oxygen metabolite levels, as well as the inhibition of hepatic mitochondrial malondialdehyde production in chronic ethanol-intoxicated rats. The hepatoprotection afforded by WKS co-treatment in chronic ethanol-intoxicated rats was associated with a reversal of altered hepatic mitochondrial antioxidant status and adenosine triphosphate (ATP) generation capacity, as well as heat shock protein 25/70 production. Therefore, WKS may offer the prospect of preventing ethanol-associated liver damage by increasing the resistance of mitochondria to oxidative stress.

Long-term treatment with danshen-gegen decoction protects the myocardium against ischemia/reperfusion injury via the redox-sensitive protein kinase C-ε/mK(ATP) pathway in rats.

Danshen-Gegen (DG) decoction, an herbal formulation comprised of radix Salvia Miltiorrhiza and radix Puerariae Lobata, is prescribed for the treatment of coronary heart disease in Chinese medicine. Experimental and clinical studies have indicated that DG decoction can reduce the extent of atherosclerosis. In the present study, using an ex vivo rat model of myocardial ischemia/reperfusion (I/R) injury, we investigated the myocardial preconditioning effect of an aqueous DG extract prepared from an optimized weight-to-weight ratio of danshen and gegen. Long-term treatment with DG extract at increasing doses (including the equivalent of a human dose) protected against myocardial I/R injury in rats. The cardioprotection afforded by DG pretreatment was paralleled by enhancements in mitochondrial antioxidant status and membrane integrity, as well as a decrease in the sensitivity of mitochondria to Ca(2+)-stimulated permeability transition in vitro, particularly under I/R conditions. Long-term treatment with the DG extract enhanced the translocation of protein kinase C-epsilon (PKCε) from the cytosol to mitochondria in rat myocardium, and this translocation was inhibited by α-tocopherol co-treatment with DG extract in rats. Long-term DG treatment may precondition the myocardium via a redox-sensitive PKCε/mK(ATP) pathway, with resultant inhibition of the mitochondrial permeability transition. The results suggest that clinical studies examining the effectiveness of DG extract given prophylactically in affording protection against myocardial I/R injury would be warranted.

Schisandrin B protects against solar irradiation-induced oxidative stress in rat skin tissue.

Schisandrin B (Sch B) and schisandrin C (Sch C), but not schisandrin A and dimethyl diphenyl bicarboxylate, protected rat skin tissue against solar irradiation-induced oxidative injury, as evidenced by a reversal of solar irradiation-induced changes in cellular reduced glutathione and α-tocopherol levels, as well as antioxidant enzyme activities and malondialdehyde production. The cytochrome P-450-mediated metabolism of Sch B or Sch C caused ROS production in rat skin microsomes. Taken together, Sch B or Sch C, by virtue of its pro-oxidant action and the subsequent eliciting of a glutathione antioxidant response, may prevent photo-aging of skin.