ecdysterone and Brain-Ischemia

We investigated the resistance of erythrocytes from rat brain venous blood to acid hemolysis in the dynamics of brain ischemic period (15, 30, 45 and 60 min), as well as in the early (5 min) and distant (24h) period of brain reperfusion. Brain ischemia-reperfusion was made in rats that received ecdysterone (standartized extract of Serratula coronata) within 18 days (per os, 1 mg/kg). Analysis of the kinetic curves of acid hemolysis showed a pronounced (60 times, from 1.45 to 85.85% at 60 min of brain ischemia and at 5 min of brain reperfusion, respectively) increase of unstable erythrocytes that hemolyzed easily (< 2.5 min). In the preconditioned rats, this increase was only 8-fold. During the period of brain ischemia, with a maximum at 15th minute, in the venous blood from brain the diene conjugates (DK) pools increased from 2.40 to 9.48 ng/mg protein and LTC4 pools increased from 1.49 to 5.98 pmol/mg protein. Even more pools of DC and LTC4 were increased at 5th min of brain reperfusion. In animals received ecdysterone, during ischemia and early reperfusion period, both pools of DC and LTC4 in venous blood were lower than that in the controls. The latter implies a possible antiradical mechanism of the protective effect of ecdysterone.

Topics: Alkenes; Animals; Antioxidants; Asteraceae; Brain; Brain Ischemia; Cells, Cultured; Ecdysterone; Erythrocytes; Hemolysis; Ischemic Preconditioning; Leukotriene C4; Neuroprotective Agents; Osmotic Fragility; Plant Extracts; Rats; Rats, Wistar; Reperfusion Injury

Based on the fact that the acute phase of ischemic stroke is accompanied by the development of heart damage, manifestations of which are oxidative stress, morphological changes in the myocardium, in the model of brain focal ischemia-reperfusion, we investigated the oxidative stress in rat heart mitochondria and possible mechanisms of cardioprotective effect of ecdysterone. Under the conditions of brain focal ischemia-reperfusion, there is an increase rate of the generation of reactive oxygen species: superoxide (*O2-) and hydroxyl radicals (*OH), pools of stable hydrogen peroxide (H2O2), accumulate products of lipid peroxidation (diene conjugates and malonic dialdehyde), as a result of activation xanthine oxidase (marker uric acid), lipooxygenase (marker leukotriene C4) and cyclooxygenase (marker tromboksane B2) ways of *O2-(generating). In animals that received ecdysterone for 18 days, under conditions of brain focal ischemia-reperfusion, the rate of reactive oxygen species generation and the pools of lipid peroxidation products were decreased, and the survival of animals was increased. The obtained results support the development of oxidative stress in heart mitochondria of rats, powerful antiradical properties ofecdysterone, its cardioprotective effect, in conditions of brain focal ischemia-reperfusion.

Topics: Animals; Brain Ischemia; Cardiotonic Agents; Ecdysterone; Heart; Hydrogen Peroxide; Hydroxyl Radical; Invertebrate Hormones; Lipid Peroxidation; Lipoxygenase; Malondialdehyde; Mitochondria, Heart; Oxidative Stress; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Wistar; Reperfusion Injury; Superoxides; Survival Analysis; Xanthine Oxidase

On the model of focal ischemia-reperfusion of the brain investigated the induction of nitrosative stress in mitochondria of rats hearts and possible mechanisms of protective action of ecdysterone. It is shown that focal ischemia-reperfusion of the brain induced in myocardial mitochondria the activation of constitutive and inducible de novo synthesis of NO by oxidation of L-arginine and not oxidative synthesis of NO through the recovery of oxidized stable metabolites of NO. Strong evidence of induction of nitrosative stress in heart mitochondria by focal ischemia-reperfusion of the brain, was a significant increase in mitochondrial pool of nitrate- and nitrite-anions and pools of nitrosothiols, that is proof of the formation and decay of peroxynitrite--a key marker of nitrosative stress. Also was observed increase in heart mitochondria by focal ischemia-reperfusion of the brain, content key regulator of de novo synthesis of NO-hydrogen sulfide and activity of inducible arginase II and, as a result, the pool of carbamide, which is also a regulator of the synthesis of NO. Previous introduction for animals herbal extract Serratsula coronata, enriched ecdysterone, reduces induction nitrosative stress in mitochondria of rats hearts under conditions of focal ischemia-reperfusion of the brain.

Topics: Animals; Antioxidants; Arginase; Arginine; Asteraceae; Brain Ischemia; Ecdysterone; Gene Expression; Mitochondria, Heart; Nitric Oxide; Nitric Oxide Synthase Type II; Oxidation-Reduction; Oxidative Stress; Peroxynitrous Acid; Plant Extracts; Rats; Rats, Wistar; Reperfusion Injury

Oxidative stress plays an important role in the pathological processes of ischemic brain damage. Many antioxidants have been shown to protect against cerebral ischemia injury by inhibiting oxidative stress both in vitro and in vivo. 20-Hydroxyecdysone (20E), an ecdysteroid hormone, exhibits antioxidative effects. For the work described in this paper, we used an in vitro oxidative damage model and an in vivo ischemic model of middle cerebral artery occlusion (MCAO) to investigate the neuroprotective effects of 20E and the mechanisms related to these effects. Treatment of cells with H(2)O(2) led to neuronal injury, intracellular ROS/RNS generation, mitochondrial membrane potential dissipation, cellular antioxidant potential descent, an increase in malondialdehyde (MDA) and an elevation of intracellular [Ca(2+)], all of which were markedly attenuated by 20E. Inhibition of the activation of the ASK1-MKK4/7-JNK stress signaling pathway and cleaved caspase-3 induced by oxidative stress were involved in the neuroprotection afforded by 20E. In addition, 20E reduced the expression of iNOS protein by inhibition of NF-κB activation. The neuroprotective effect of 20E was also confirmed in vivo. 20E significantly decreased infarct volume and the neurological deficit score, restored antioxidant potential and inhibited the increase in MDA and TUNEL-positive and cleaved caspase-3-positive cells in the cerebral cortex in MCAO rats. Together, these results support that 20E protects against cerebral ischemia injury by inhibiting ROS/RNS production and modulating oxidative stress-induced signal transduction pathways.

Topics: Animals; Antioxidants; Apoptosis; Brain Ischemia; Ecdysterone; Free Radical Scavengers; Hydrogen Peroxide; Infarction, Middle Cerebral Artery; MAP Kinase Signaling System; Membrane Potential, Mitochondrial; Neurons; Neuroprotective Agents; NF-kappa B; Oxidative Stress; Rats; Rats, Sprague-Dawley; Reperfusion Injury; Signal Transduction

We reported previously that ecdysterone (EDS) improves neurologic function after experimental stroke. However, the underlying mechanism remained unclear. The present study was conducted to test whether ecdysterone improves neurologic function by enhancing astrocyte activation and angiogenesis after focal cerebral ischemia in rats.. Focal cerebral ischemia model was conducted by middle cerebral artery occlusion (MCAO). EDS was intraperitoneally injected at 20 mg kg1 daily for 7 days after MCAO. Neurologic recovery was assessed using the neurologic severity scores. Microvessel density and GFAP expression were detected with immunostaining and analyzed quantitatively with image system.. Treatment with EDS significantly improved functional recovery, along with increases in density of cerebral microvessels and astrocyte activation. Microvessel density was significantly higher in EDS treated group than in ischemia control group at all time points, and reached a peak on day 14. EDS treated group had substantial increment in GFAP immunoreactive cells, darker staining color, more and longer nerve processes, higher GFAP expression and area of immunoreactive cells at each time point.. Our data suggest that EDS treatment enhanced angiogenesis and astrocyte activation which could contribute to functional recovery.

Topics: Analysis of Variance; Animals; Astrocytes; Brain Ischemia; Disease Models, Animal; Ecdysterone; Factor VIII; Glial Fibrillary Acidic Protein; Microvessels; Neovascularization, Physiologic; Rats; Rats, Sprague-Dawley; Recovery of Function; Severity of Illness Index; Time Factors