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Background/purpose: Calycosin-7-O-β-D-glucoside (CG), a calycosin derivative compound derived from Astragali Radix, has protective effect against ischemia/reperfusion injury as well as bacterial endotoxin-induced vascular cell injury. In the present study, we ascertained whether CG could reduce myocardial injury in heatstroke rats.Methods: Heat stroke was induced by exposing anaesthetized rats to heat stress (43 °C for 70 min). Rats were given an i.p. dose of CG (26.8 mg/ml/kg) or vehicle solution (ml/kg) 15 min before the start of heat stress and immediately after termination of heat stress. Left ventricular performance, myocardial injury markers in the blood, and myocardial damage scores were assessed in heat stroke rats treated with or without CG. Additionally, cardiac levels of oxidative stress and inflammatory status were estimated simultaneously.Results: At the time point of heat stroke onset, compared with normothermic controls, group rats with vehicle solution had significantly decreased survival rate, increased hyperthermia, decreased left ventricular stress markers, and increased cardiac damage scores. Compared with group rats with vehicle solution, group rats with CG had significantly improved survival rate, decreased hyperthermia, decreased cardiac ischemic, inflammatory, and oxidative damage.Conclusion: We thus conclude that myocardial injury can be a pressing need for the design of diagnostic and therapeutic modalities for heat stroke. In particular, our data indicate that CG protects against heat stroke in rats by mitigating myocardial injury. [ABSTRACT FROM AUTHOR]

Heat stroke is characterized by hyperthermia, systemic inflammation, and multiple organ failure including arterial hypotension. This definition can be fulfilled by a rat model of heat stroke used in the present study. Anesthetized animals were exposed to heat exposure (43 °C for 70 min) and then returned to room temperature (26 °C) for recovery. One hour before heat exposure, an intraperitoneal dose of quercetin (30 mg/kg) or vehicle (normal saline 1 ml/kg) was administered to the experimental groups of rats. Additional injection was administered immediately after the onset of heat stroke. Immediately after the onset of heat stroke. Vehicle-treated rats displayed (i) hyperthermia; (ii) suppressed left ventricular function; (iii) decreased contents of cardiac total antioxiant capacity (e.g., superoxide dismutase, glutathione peroxidase, catalase); (iv) increased contents of cardiac oxidative capacity malondialdehyde and thiobarbituric acid reactive substances; (v) increased cardiac levels of pro-inflammatory cytokines tumor necrosis factor-α and interleukin-6; and (vi) decreased cardiac levels of an anti-inflammatory cytokine interleukin 10. Histopathologic and survival observation provided supportive evidence for biochemical analyses. These heat stroke reactions all can be significantly attenuated by quercetin therapy. Our data suggest that quercetin therapy might improve outcomes of heat stroke in rats by attenuating excessive hyperthermia as well as myocardial injury. The protective effects of quercetin could be attributed to anti-lipid peroxidative, anti-oxidant, and anti-inflammatory properties. [ABSTRACT FROM AUTHOR]

Background/Purpose: Lifelong overexpression of heat shock protein (HSP) 72 in skeletal muscle is known to protect against age-related oxidative stress and muscle damage. This study aimed to ascertain whether exhaustive exercise (EE)-induced muscle fatigue and damage can be prevented by lifelong overexpression of HSP72 in skeletal muscle. Methods: Transgenic mice heterozygous for the porcine HSP70.2 gene ([+]HSP72) and transgene-negative littermate controls ([–]HSP72) were subjected to an EE protocol. Mice were randomly divided into four groups: sedentary [–]HSP72, sedentary [+]HSP72, EE [–]HSP72, and EE [+]HSP72. Animals were killed 82 minutes after the start of EE to determine muscular levels of HSP72, serum levels of superoxide dismutase (SOD, an antioxidant enzyme) and lactate (an indicator of muscle fatigue), muscular levels of matrix metalloproteinase (an indicator of inflammatory myopathies), and muscular damage. Results: During the test, the latency value for the occurrence of EE was 79–85 minutes and 100–110 minutes for [–]HSP72 and [+]HSP72 mice, respectively. After EE, [+]HSP72 mice had significantly higher serum SOD and significantly lower serum lactate, muscular matrix metalloproteinase or myeloperoxidase activity, and muscle damage compared to [–]HSP72 mice. Conclusion: The results suggest that HSP72 overexpression in skeletal muscle may improve muscle fatigue and damage in EE by reducing oxidative damage and phagocytic infiltration, at least in mice. [ABSTRACT FROM AUTHOR]

We first explore whether aircraft noise (AN) induces cognitive deficit via inducing oxidative damage in multiple vital organs including intestines, hearts and hippocampus tissues. Second, we explore whether the AN-induced cognitive deficits and inflammatory and oxidative damage to multiple organs can be alleviated by Astaxanthin (AX) pretreatment. Cognitive deficits were induced by subjecting the mice to AN 2 h daily for 7 consecutive days. An intragastrical dose of AX emulsifier (at the dose of daily feed intake [6 g] of a mouse three times weekly) was given to mice for consecutive 8 weeks prior to the start of AN. Cognitive functions were evaluated by using passive avoidance apparatus, Y-maze, Morris water maze and novel recognition test. Intestinal permeability was determined by measuring the intestinal clearance of fluorescein-isothiocyante. Evans Blue extravasation assay was used to measure the permeability of blood-brain-barrier. Inflammatory and oxidative damage to multiple organs were determined by measuring several pro-inflammatory cytokines and oxidative stress indicators in intestines; hearts and hippocampus. Mice treated with AN displayed exacerbated stress reactions, cognitive deficits, gut barrier hyperpermeability, increased upload of lipopolysaccharide translocation, systemic pro-inflammatory cytokines overproduction, blood-brain-barrier hyperpermeability, hippocampal neuroinflammation and increased levels of oxidative stress indicators in intestine, heart and hippocampus. All of the above-mentioned disorders caused by AN were significantly (P < 0.05) reversed by AX. Our data indicate that AX pretreatment alleviates cognitive deficits in aircraft noised mice by attenuating inflammatory and oxidative damage to intestines, hearts and hippocampal tissues. [ABSTRACT FROM AUTHOR]