Proanthocyanidins alleviate pentylenetetrazole-induced epileptic seizures in mice via the antioxidant activity

The role of oxidative stress in the initiation and progress of epilepsy is well established. Proanthocyanidins (PACs), a naturally occurring polyphenolic compound, have been reported to possess a broad spectrum of pharmacological and therapeutic properties against oxidative stress. However, the protective effects of proanthocyanidins against epilepsy have not been clarified. In the present study, we used the pentylenetetrazole (PTZ)-induced epilepsy mouse model to explore whether proanthocyanidins could help to reduce oxidative stress and protect against epilepsy. Mice were allocated into four groups (n?=?14 per each group): control, PTZ (60 mg/kg, intraperitoneally), PACs?+?PTZ (200 mg/kg, p.o.) and sodium valproate (VPA)?+?PTZ (200 mg/kg, p.o.). PTZ injection caused oxidative stress in the hippocampal tissue as represented by the elevated lipid peroxidation and NO synthesis and increased expression of iNOS. Furthermore, depleted levels of anti-oxidants, GSH, GR, GPx, SOD, and CAT also indicate that oxidative stress was induced in mice exposed to PTZ. Additionally, a state of neuroinflammation was recorded following the developed seizures. Moreover, neuronal apoptosis was recorded following the development of epileptic convulsions as confirmed by the elevated Bax and caspase-3 and the decreased Bcl2 protein. Moreover, AChE activity, DA, NE, 5-HT, brain-derived neurotrophic factor levels, and gene expression of Nrf2 have decreased in the hippocampal tissue of PTZ exposed mice. However, pre-treatment of mice with PACs protected against the generation of oxidative stress, apoptosis, and neuroinflammation in the PTZ exposed mice brain as the biomarkers for all these conditions was bought to control levels. In addition, the gene expression of Nrf2 was significantly upregulated following PACs treatment. These results suggest that PACs can ameliorate oxidative stress, neuroinflammation, and neuronal apoptosis by activating the Nrf2 signaling pathway in PTZ induced seizures in mice.

     

Topiramate and Vitamin E Modulate the Electroencephalographic Records,Brain Microsomal and Blood Antioxidant Redox System in Pentylentetrazol-Induced Seizure of Rats

We investigated the effects of vitamin E and topiramate (TPM) administrations on pentylentetrazol (PTZ)–induced blood and brain toxicity in rats. Forty rats were randomly divided into five equal groups. The first and second groups were used for the control and PTZ groups, respectively. Fifty or 100 mg TPM were administered to rats constituting the third and fourth groups for 7 days, respectively. The TPM and vitamin E combination was given to animals in the fifth group. At the end of 7 days, all groups except the first received a single dose of PTZ. Blood and brain samples were taken at 3 hrs after PTZ administration. Lipid peroxidation levels of plasma, erythrocyte, brain cortex and brain microsomal fraction; nitric oxide levels of serum; and the number of spikes and epileptiform discharges of the EEG were increased by PTZ administration. Plasma and brain vitamin E concentration, erythrocyte glutathione peroxidase (GSH-Px) activity and latency to first spike of the EEG were decreased by PTZ. Plasma lipid peroxidation levels in the third group and plasma and erythrocyte lipid peroxidation levels in the fifth group were decreased compared to the second group, whereas brain vitamin C, vitamin E, erythrocyte GSH-Px and reduced glutathione (GSH) values increased in the fifth group. Brain microsomal GSH levels and EEG records in the third, fourth and fifth groups were restored by the TPM and vitamin E treatment. In conclusion, TPM and vitamin E seems to have protective effects on PTZ-induced blood and brain toxicity by inhibiting free radicals and supporting the antioxidant redox system.     

Dose-finding study with nicotine as a proconvulsant agent in PTZ-induced seizure model in mice

The present study was conducted to investigate the possible interaction between low doses of nicotine and pentylenetetrazole (PTZ) in vivo and also to evaluate the influence of nicotine on the antiseizure efficacy of topiramate and sodium valproate in the PTZ-induced seizure model in mice. Graded dose–response study with nicotine showed the CD50 value for nicotine at 6.76 mg/kg. i.p. Subtheshold dose of nicotine (4 mg/kg, i.p.) pretreatment significantly decreased the CD50 value for PTZ from 47.86 mg/kg, i.p. (of PTZ per se) to 31.62 mg/kg, i.p. Sodium valproate but not topiramate, significantly inhibited PTZ-induced seizures in mice with an ED50 value of 177.83 mg/kg, i.p. Nonconvulsive dose of nicotine (1 mg/kg, i.p.) significantly antagonized the protective efficacy of sodium valproate against PTZ-induced seizures and increased the ED50 value to 338.84 mg/kg, i.p. PTZ-induced seizures significantly increased the mouse brain levels of MDA and reduced the level of GSH while sodium valproate reversed such changes. Nicotine pretreatment reversed the anti-lipid peroxidative action of sodium valproate in the PTZ-induced seizure model in mice. The study highlighted the convulsant as well as proconvulsant role of nicotine and established dose discrimination for nicotine as a proconvulsant agent and an anti-antiseizure agent. The study bears significant clinical relevance particularly amongst epileptic smokers who may show failure of efficacy of antiepileptic agents and present with breakthrough seizure attacks on exposure to nicotine.     

Capparis ovata Modulates Brain Oxidative Toxicity and Epileptic Seizures in Pentylentetrazol-Induced Epileptic Rats

It has been widely suggested that oxidative stress products play an important role in the pathophysiology of epilepsy. Capparis ovata (C. ovata) may useful treatment of epilepsy because it contains antioxidant flavonoids. The current study was designed to determine the effects of C. ovata on lipid peroxidation, antioxidant levels and electroencephalography (EEG) records in pentylentetrazol (PTZ)-induced epileptic rats. Thirty-two rats were randomly divided into four groups. First group was used as control although second group was PTZ group. Oral 100 and 200 mg/kg C. ovata were given to rats constituting the third and fourth groups for 7 days before PTZ administration. Second, third and forth groups received 60 mg/kg PTZ for induction of epilepsy. Three hours after administration of PTZ, EEG records, brain cortex and blood samples were taken all groups. The lipid peroxidation levels of the brain cortex, number of spikes and epileptiform discharges of EEG were higher in PTZ group than in control and C. ovata group whereas they were decreased by C. ovata administration. Vitamin A, vitamin C, vitamin E and β-carotene concentrations of brain cortex and latency to first spike of EEG were decreased by the PTZ administration although the brain cortex and plasma vitamin concentrations, and brain cortex and erythrocyte glutathione and glutathione peroxidase values were increased in PTZ + 100 and PTZ + 200 mg C. ovata groups. In conclusion, C. ovata administration caused protection against the PTZ-induced brain oxidative toxicity by inhibiting free radical and epileptic seizures, and supporting antioxidant redox system.     

Effect of Ibuprofen on Autophagy of Astrocytes During Pentylenetetrazol-Induced Epilepsy and its Significance: An Experimental Study

Epilepsy is a chronic neurological disease. Astrogliosis is an important pathological change in epileptic lesions. Studies have reported that ibuprofen can affect autophagy and/or inhibit cell proliferation in many diseases. This study investigated the effect and significance of ibuprofen on autophagy of astrocytes during pentylenetetrazol (PTZ) induced epilepsy. 60 male Sprague–Dawley (SD) rats were randomly divided into five groups: control group (received normal saline), PTZ group, 3-methyladenine (3-MA)?+?PTZ group, ibuprofen?+?PTZ group and 3-MA?+?ibuprofen?+?PTZ group. Dose of each agent was 35 mg/kg (PTZ), 10 mg/kg (3-MA) and 30 mg/kg (ibuprofen) and all drugs were administered intraperitoneally 15 times on alternate days (29 days). Human astrocytes were cultured in vitro. Behavioral performance (i.e., latency, grade and duration of seizures) and EEG of rats were observed and recorded. Proliferation of astrocytes was detected by CCK-8 method. Immunofluorescence and Western blot test were used to detect the expression of LC3 and GFAP. Mean number, grade and duration of seizures were markedly reduced in ibuprofen?+?PTZ group and 3-MA?+?ibuprofen?+?PTZ group (P?<?0.05). Similarly, peak of EEG waves were markedly reduced in ibuprofen?+?PTZ group and 3-MA?+?ibuprofen?+?PTZ group (P?<?0.05). Compared to the control group, the level of LC3 in ibuprofen group was significantly increased in vitro (P?<?0.05). While, levels of LC3 were significantly higher and that of GFAP were significantly lower in ibuprofen?+?PTZ group (P?<?0.05) compared to PTZ group in vivo. Ibuprofen reduces the proliferation of astrocytes by increasing autophagy, thus affecting the development of epilepsy. Therefore, ibuprofen may be used as an adjuvant to improve efficacy of treatment in epilepsy.

     

Effect of Vitamin E on Blood-Brain Barrier Permeability in Aged Rats with PTZ-Induced Convulsions

The effect of vitamin E on blood-brain barrier (BBB) permeability was studied under conditions of pentylenetetrazole (PTZ)-induced convulsions in aged (23- to 24-month-old) male albino rats; Evans Blue was used as a tracer. The BBB permeability was found to increase considerably in rats with PTZ-evoked seizures; the Evans Blue contents in the left and right hemispheres and cerebellum + brainstem region were significantly higher than those in the control. Vitamin E at a dose of 70 mg/kg exerted practically no beneficial effect on the increased BBB permeability in rats with seizures, while a greater dose of vitamin E (700 mg/kg) exerted a significant protective effect, especially with respect to the cerebellum + brainstem regions (P < 0.01). The seizure-related rise in the arterial blood pressure was also smaller in the latter experimental group. Thus, our observations confirm the importance of the vitamin E dose as a protective factor for BBB permeability and demonstrate that the dose dependence of this antioxidant in aged animals differs from that in younger organisms.     

Effect of thiamazole on kainic acid-induced seizures in mice

Kainic acid (KA) induced epileptic seizures in mice is a commonly used experimental model of epilepsy. Previous studies have suggested the roles of various neurotransmitters and oxidative stress in KA-induced seizures. An important role of hypothyroidism has also been suggested in epilepsy. Thiamazole (TZ) is an anti-hyperthyroid drug with antioxidant property. This study reports the effect of TZ on KA-induced epileptic seizures in mice, produced by intraperitoneal (IP) injection of KA (18 mg/kg). Prior to KA injection, the animals were treated with TZ (12.5, 25 and 50 mg/kg IP). Our results showed that in KA alone group, about half of the animals developed seizures. Pre-treatment of mice with TZ significantly increased the frequency of seizures in dose-dependent manner. Administration of TZ significantly reduced the latency time and aggravated the severity of seizures. TZ also increased the mortality in KA-treated mice. Striatal dopamine and serotonin levels were markedly increased in KA alone treated mice, which were not significantly affected by TZ treatment. Among the indices of oxidative stress, we observed a significant reduction in cerebral vitamin E whereas the levels of cerebral malondialdehyde and conjugated dienes were significantly increased in animals with high severity of seizures. In conclusion, TZ potentiated the frequency and severity of experimental seizure in mice. There is a possibility of altered metabolism of KA in presence of TZ that might have potentiated the toxicity of KA. These findings suggest a caution while administering anti-hyperthyroid drugs in epileptic seizures.     

Antioxidant activity elicited by low dose of caffeine attenuates pentylenetetrazol-induced seizures and oxidative damage in rats

Although caffeine supplementation has a beneficial effect on people with neurological disorders, its implications for oxidative damage related to seizures are not well documented. Thus the aim of this study was to investigate the effects of two weeks caffeine supplementation (6 mg/kg; p.o.) on seizures and neurochemical alterations induced by pentylenetetrazol (PTZ 60 mg/kg i.p.). Statistical analyses showed that long-term rather than single dose caffeine administration decreased the duration of PTZ-induced seizures in adult male Wistar rats as recorded by cortical electroencephalographic (EEG) and behavioral analysis. The quantification of EEG recordings also revealed that caffeine supplementation protected against a wave increase induced by PTZ. Neurochemical analyses revealed that caffeine supplementation increased glutathione (GSH) content per se and protected against the increase in the levels of thiobarbituric acid reactive substances (TBARS) and oxidized diclorofluoresceine diacetate (DCFH-DA). Also, caffeine prevent the decrease in GSH content and Na⁺, K⁺-ATPase activity induced by PTZ. Our data also showed that the infusion of L-buthionine sulfoximine (BSO; 3.2 μmol/site i.c.v), an inhibitor of GSH synthesis, two days before injecting PTZ reversed the anticonvulsant effect caused by caffeine. BSO infusion also decreased GSH content and Na⁺, K⁺-ATPase activity. However, it increased DCFH-DA oxidation and TBARS per se and reversed the protective effect of caffeine. Results presented in this paper support the neuroprotective effects of low long-term caffeine exposure to epileptic damage and suggest that the increase in the cerebral GSH content caused by caffeine supplementation may provide a new therapeutic approach to the control of seizure.     

Tetrandrine Ameliorates Traumatic Brain Injury by Regulating Autophagy to Reduce Ferroptosis

Traumatic brain injury (TBI) is the leading cause of death and disability in trauma patients. However, the effects and mechanism of autophagy after TBI remain unclear. This study aimed to investigate whether tetrandrine could ameliorate TBI through autophagy to reduce ferroptosis. A mice model for TBI was implemented. Behavioral and histomorphological experiments were performed to evaluate outcomes of the mice. The ferroptosis levels was detected by Perls staining. Enzyme-linked immunosorbent assay (ELISA) was applied to detect malondialdehyde (MDA), glutathione (GSH), and glutathione peroxidase 4 (GPX4) levels in the brain tissue. Western blot test was performed to detect Beclin 1, light chain 3 (LC3) II/I, p62, GPX4, SCL7A11, and ferritin heavy chain 1 (FTH1) levels, and the expression of LC3B, Beclin 1, GPX4, and FTH1 in the brain tissue was detected by immunofluorescence (IF). The behavioral and histomorphological results demonstrated that tetrandrine improved the neurological function and cerebral edema on days 1, 3, and 7 after TBI. The ELISA results suggested that tetrandrine reduced the MDA concentration and increased GSH concentration on days 1, 3, and 7 after TBI. IF staining and Perls staining reflected that tetrandrine promoted autophagy and inhibited ferroptosis on days 1, 3, and 7 after TBI, respectively. Tetrandrine further improved the neurological function, cerebral edema, autophagy, and ferroptosis on days 1, 3, and 7 after TBI after adding the autophagy inducer rapamycin. The effect of TET in alleviating TBI increased with the increase of time and dose. Tetrandrine ameliorated TBI by regulating autophagy to reduce ferroptosis, providing a new therapeutic strategy for TBI.

     

GPX4 and vitamin E cooperatively protect hematopoietic stem and progenitor cells from lipid peroxidation and ferroptosis

Ferroptosis, a newly defined mode of regulated cell death caused by unbalanced lipid redox metabolism, is implicated in various tissue injuries and tumorigenesis. However, the role of ferroptosis in stem cells has not yet been investigated. Glutathione peroxidase 4 (GPX4) is a critical suppressor of lipid peroxidation and ferroptosis. Here, we study the function of GPX4 and ferroptosis in hematopoietic stem and progenitor cells (HSPCs) in mice with Gpx4 deficiency in the hematopoietic system. We find that Gpx4 deletion solely in the hematopoietic system has no significant effect on the number and function of HSPCs in mice. Notably, hematopoietic stem cells (HSCs) and hematopoietic progenitor cells lacking Gpx4 accumulated lipid peroxidation and underwent ferroptosis in vitro. α-Tocopherol, the main component of vitamin E, was shown to rescue the Gpx4-deficient HSPCs from ferroptosis in vitro. When Gpx4 knockout mice were fed a vitamin E-depleted diet, a reduced number of HSPCs and impaired function of HSCs were found. Furthermore, increased levels of lipid peroxidation and cell death indicated that HSPCs undergo ferroptosis. Collectively, we demonstrate that GPX4 and vitamin E cooperatively maintain lipid redox balance and prevent ferroptosis in HSPCs.Subject terms: Cell biology, Physiology, Stem-cell research     

Halogenated aromatic amino acid 3,5-dibromo-<Emphasis Type="SmallCaps">d</Emphasis>-tyrosine produces beneficial effects in experimental stroke and seizures

The effects of the halogenated aromatic amino acid 3,5-dibromo-d-tyrosine (3,5-DBr-d-Tyr) were studied in rat models of stroke and epileptic seizures caused by middle cerebral artery occlusion (MCAo) through respective intracerebral injection of endothelin-1 (ET-1) and intraperitoneal (i.p.) injection of pentylenetetrazole (PTZ). 3,5-DBr-d-Tyr was administered as three bolus injections (30 or 90 mg/kg, i.p.) starting at 30, 90, and 180 min after ET-1 administration or as a single bolus (30 mg/kg, i.p.) 15 min prior to PTZ administration. Neurological deficits and infarct volume were estimated 3 days after ET-1 administration and seizure score was assessed during the first 20 min after PTZ administration. The safety of 3,5-DBr-d-Tyr was evaluated in control animals using telemetry to measure cardiovascular parameters and immunostaining to assess the level of activated caspase-3. 3,5-DBr-d-Tyr significantly improved neurological function and reduced infarct volume in the brain even when the treatment was initiated 3 h after the onset of MCAo. 3,5-DBr-d-Tyr significantly depressed PTZ-induced seizures. 3,5-DBr-d-Tyr did not cause significant changes in arterial blood pressure, heart rate and spontaneous locomotor activity, nor did it increase the number of activated caspase-3 positive cells in the brain. We conclude that 3,5-DBr-d-Tyr, by alleviating the deleterious effects of MCAo and PTZ in rats with no obvious intrinsic effects on cardiovascular parameters and neurodegeneration, exhibits promising potential as a novel therapeutic direction for stroke and seizures.     

Effect of Anacyclus pyrethrum on Pentylenetetrazole-Induced Kindling, Spatial Memory, Oxidative Stress and Rho-Kinase II Expression in Mice

Anacyclus pyrethrum (A. pyrethrum) has been reported to exhibit anticonvulsant activity. In the present study, the effect of hydro-alcoholic extract of A. pyrethrum root (HEAP) on pentylenetetrazole (PTZ) induced kindling, spatial memory, oxidative stress and rho kinase (ROCK II) was assessed. Male albino mice (25–30 g) were used in the study. PTZ (35 mg/kg, i.p. on alternate days) was injected to induce kindling and PTZ (70 mg/kg, i.p) challenge was given 7 days post-kindling. HEAP was administered orally daily in the doses of 100, 250 and 500 mg/kg along with PTZ injections during the kindling process and continued till PTZ challenge post kindling. Spatial memory was assessed using Morris water maze test. Oxidative stress parameters [malondialdehyde (MDA) and reduced glutathione (GSH)] and ROCK II expression were estimated in whole brain at the end of the study. Pre-treatment with HEAP (250 and 500 mg/kg) showed significant increase in the myoclonic jerk latency and delay in the development of kindling. A significant decrease in mortality was observed at higher doses of HEAP (250 and 500 mg/kg). Pre-treatment with HEAP significantly increased the number of platform crossings and decreased the escape latency, as opposed to the PTZ group, thus showing protection against memory deficit. HEAP pre-treatment also attenuated the oxidative stress induced by PTZ kindling. PTZ induced kindling increased the ROCK II expression whereas, HEAP pre-treatment attenuated the increase in ROCK II expression. To conclude, HEAP pre-treatment showed antiepileptic effect and also showed protection against cognitive impairment by decreasing oxidative stress and ROCK II expression in PTZ kindled mice.     

Preferential increase in the hippocampal synaptic vesicle protein 2A (SV2A) by pentylenetetrazole kindling

The present study evaluated the expressional levels of synaptic vesicle protein 2A (SV2A) and other secretary machinery proteins (i.e., soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complexes, Munc18-1, N-ethylmaleimide-sensitive factor (NSF) and soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP)) in a pentylenetetrazole (PTZ) kindling model. Repeated administration of sub-convulsive PTZ (40 mg/kg, i.p.) progressively increased seizure susceptibility in mice and consistently induced clonic seizures in most animals tested at 15 days after the treatment. Western blot analysis revealed that, among the secretary machinery proteins examined, hippocampal SV2A was selectively elevated by PTZ kindling. PTZ kindling-induced SV2A expression appeared region-specific and the SV2A levels in the cerebral cortex or cerebellum were unaltered. In addition, SV2A expression by PTZ kindling was prominent in the hilar region of the dentate gyrus (DG) where GABAergic interneurons are located, but not in other hippocampal regions (e.g., the stratum lucidum of the CA3 and synaptic layers surrounding CA1 or CA3 pyramidal neurons). These findings suggest that PTZ kindling preferentially elevates SV2A expression in the hippocampus probably as a compensatory mechanism to activate the inhibitory neurotransmission.     

Garlic and vitamin E provides antioxidant defence in tissues of female rats treated with nicotine

Nicotine is known to induce oxidative stress in rat tissues and the antioxidant properties of garlic have been reported. This study was designed to determine if the peroxidative damage caused by nicotine administration can be effectively prevented with garlic juice, and vitamin E, a known antioxidant.Four groups of six rats each were divided into: Group I: (control) received 0.2ml of 0.9% normal saline, group II (received nicotine 0.6mg/kg b.w subcutaneously), group III (received nicotine 0.6mg/kg b.w + garlic juice 100mg/kg b.w orally), and group IV (received nicotine 0.6mg/kg b.w + Vitamin E 100mg/kg b.w orally). All animals were treated for 21 days. The pituitary gland, ovary, uterus, heart, liver and kidney of the animals were harvested, weighed and homogenized. Malondialdehyde (MDA), superoxide dismutase (SOD) and reduced glutathione (GSH) were then measured.Concentration of MDA was significantly increased in tissues of nicotine treated rats when compared with the control. In group III and IV, MDA levels were significantly reduced when compared with nicotine group. The activities of SOD and GSH significantly decreased in group II (nicotine only) rat tissues, while it was significantly increased in group III and IV rat tissues. The study showed that garlic juice extract (100mg/kg b.w) and vitamin E (100mg/kg b.w) administration prevented oxidative damage in rat tissues treated with nicotine. The study also showed that vitamin E has a more potent antioxidant activity than garlic juice in preventing nicotine induced oxidative damage in rat. Keywords: Nicotine, Vitamin E, Garlic, antioxidant.     

Effects of lipopolysaccharide on blood-brain barrier permeability during pentylenetetrazole-induced epileptic seizures in rats

We investigated the effects of lipopolysachharide (LPS) on functional and structural properties of the blood-brain barrier (BBB) during pentylenetetrazole (PTZ)-induced epileptic seizures in rats. Arterial blood pressure was significantly elevated during epileptic seizures irrespective of LPS pretreatment. Plasma levels of interleukin (IL)-1, interleukin (IL)-6, nitric oxide (NO) and malondialdehyde (MDA) increased while catalase concentrations decreased in animals treated with LPS, PTZ and LPS plus PTZ. The significantly increased BBB permeability to Evans blue (EB) dye in the cerebral cortex, diencephalon and cerebellum regions of rats by PTZ-induced seizures was markedly reduced upon LPS pretreatment. Immunoreactivity for tight junction proteins, zonula occludens-1 and occludin, did not change in brain vessels of animals treated with PTZ and LPS plus PTZ. Glial fibrillary acidic protein immunoreactivity was increased in LPS, but not in PTZ and LPS plus PTZ. These results indicate that LPS pretreatment reduces the passage of EB dye bound to albumin into the brain, at least partly, by increasing plasma NO and IL-6 levels during PTZ-induced epileptic seizures. We suggest that LPS may provide protective effects on the BBB integrity during epileptic seizures through transcellular pathway, since the paracellular route remained unaffected by LPS and LPS plus PTZ.     

Influence of dietary vitamin E (DL-alpha-tocopheryl acetate) and diludine (diethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate) levels on growth and lipid peroxidation in rainbow trout,Oncorhynchus mykiss

We aimed to investigate the influence of dietary vitamin E and diludine on growth and lipid peroxidation (malondialdehyde; MDA) in rainbow trout. Fish (1.5 g) were fed different dietary levels of vitamin E (0, 50 and 100 mg/kg) and diludine (0, 0.5 and 1 g/kg) for 10 weeks. Growth performance and feed conversion ratio (FCR) were significantly affected by dietary vitamin E (p < .05) but not diludine. Fish fed 50 mg/kg dietary vitamin E with no diludine had significantly better growth and lower FCR than those fed vitamin E free diets. Liver vitamin E content was significantly influenced by dietary vitamin E and diludine (p < .05). The highest hepatic vitamin E was in fish fed the highest dietary vitamin E and diludine levels. Hepatic MDA level was significantly affected by dietary vitamin E and diludine (p < .05), decreasing with the increase in both dietary vitamin E and diludine. According to our results, diludine had no significant effect on growth; however, decreased hepatic lipid peroxidation independent of vitamin E. Our results reveal that 50 mg/kg vitamin E content is suitable for optimal growth and FCR in rainbow trout juveniles. However, dose dependent effects of dietary diludine remain uncertain and need further researches.     

桃叶珊瑚苷对冠心病大鼠Nrf2介导的铁死亡途径的影响

摘要 目的：探讨桃叶珊瑚苷（AU）对冠心病（CHD）大鼠的治疗作用及其对核因子红系2相关因子2（Nrf2）介导的铁死亡途径的影响。方法：将大鼠分为NC组、CHD组、L-AU组、M-AU组、H-AU组和ML385组,每组12只大鼠。NC组为正常饲料喂养的对照大鼠,其他组均为高脂饮食联合腹腔注射垂体后叶素诱导的CHD模型大鼠。NC组和CHD组大鼠灌胃0.3%羧甲基纤维素钠（CMC）,L-AU组、M-AU组和H-AU组大鼠灌胃20、40和80 mg/kg/d的桃叶珊瑚苷,ML385组大鼠灌胃80 mg/kg/d的桃叶珊瑚苷并腹腔注射30 mg/kg/d Nrf2抑制剂ML385,共给药4周。分别检测各组大鼠的心功能指标[射血分数（EF）和短轴缩短率（FS）]、血清指标[肌酸激酶同工酶MB（CK-MB）、乳酸脱氢酶（LDH）、总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白胆固醇（LDL-C）、高密度脂蛋白胆固醇(HDL-C）和游离脂肪酸（FFA）]、心肌组织氧化应激指标[还原型谷胱甘肽（GSH）和丙二醛（MDA）]和心肌组织Fe²⁺含量。通过苏木素伊红（HE）染色观察大鼠心肌形态。通过Western blot检测大鼠心肌组织中Nrf2、Kelch样ECH相关蛋白1（Keap1）、血红素加氧酶-1（HO-1）、NADPH：醌氧化还原酶-1（NQO-1）、谷胱甘肽过氧化物酶4（GPX4）、铁蛋白重链1（FTH1）和膜铁转运蛋白1（FPN1）的蛋白水平。结果：与NC组比较,CHD组大鼠的EF和FS水平降低,CK-MB和LDH水平升高,心肌出现明显损伤;TC、TG、LDL-C、FFA和MDA水平升高,HDL-C和GSH水平降低;Nrf2、HO-1、NQO-1、GPX4、FTH1和FPN1蛋白水平降低,Keap1蛋白水平升高,Fe²⁺含量升高（P<0.05）。与CHD组比较,L-AU组、M-AU组和H-AU组大鼠的EF和FS升高,CK-MB和LDH水平降低,心肌形态明显改善;TC、TG、LDL-C、FFA和MDA水平降低,HDL-C和GSH水平升高;Nrf2、HO-1、NQO-1、GPX4、FTH1和FPN1蛋白水平升高,Keap1蛋白水平降低,Fe²⁺含量降低（P<0.05）。与H-AU组比较,ML385组大鼠的EF和FS降低,CK-MB和LDH水平升高,心肌损伤加重,TC、TG、LDL-C、FFA和MDA水平升高,HDL-C和GSH水平降低;Nrf2、HO-1、NQO-1、GPX4、FTH1和FPN1蛋白水平降低,Keap1蛋白水平升高,Fe²⁺含量升高（P<0.05）。结论：桃叶珊瑚苷表现出了良好的抗冠心病作用,其机制与抑制Nrf2介导的铁死亡途径有关。     

Effects of X-ray radiation on lipid peroxidation and antioxidant systems in rabbits treated with antioxidant compounds

The aim of this study was to investigate the effects of supplemental antioxidant vitamins and minerals on lipid peroxidation and on the antioxidant systems in rabbits exposed to X-rays. The rabbits were divided into two experimental groups and one control group, each group containing seven rabbits. The first group (VG) received daily oral doses of vitamin E (460 mg/kg live weight) and vitamin C (100 mg/kg live weight). The second group (MG) was fed a mineral-enriched diet that contained 60 mg manganese chloride, 40 mg zinc sulfate, and 5 mg copper sulfate per kilogram of feed. The third group served as controls and received only a standard diet. Blood samples were obtained before and after the supplementation with vitamins or minerals, as well as before and after irradiation with a total dose of 550-rad X-rays. The blood samples were analyzed for their content of malondialdehyde (MDA), plasma vitamins C and E, retinol, reduced glutathione (GSH), and glutathione peroxidase activity (GPx). After irradiation, the control group showed increased levels of MDA and activity of GPx (p<0.05), whereas the levels of GSH, vitamin C, and vitamin E were decreased. In the VG, the concentration of MDA was lower (p<0.05), and the concentration of GSH and vitamins C and E were higher (p<0.05) when compared to controls. In the MG, the concentrations of MDA, GSH, vitamin C, and retinol were not affected by the mineral administration and radiation. The level of vitamin E in the MG increased with mineral administration (p<0.05), but decreased after irradiation (p<0.05). For the control group, the level of GSH was higher than in the two experimental groups. After irradiation, the VG animals had vitamin E and C levels that were higher than in MG and control groups (p<0.05). The activity of GPx was not affected by vitamin or mineral supplementation or by irradiation. We conclude that the supplementation with antioxidant vitamins and minerals may serve to reinforce the antioxidant systems, thus having a protective effect against cell damage by X-rays.     

Combination Therapy of Gabapentin and N-Acetylcysteine Against Posttraumatic Epilepsy in Rats

Traumatic brain injury (TBI) is a major public health problem worldwide that is associated with increased mortality and morbidity. Posttraumatic epilepsy (PTE) is one of the sequelae of TBI. The aim of this study was to investigate the role of N-acetylcysteine (NAC) as an adjuvant on the efficacy of levetiracetam (LEV) and gabapentin (GBP) in PTE model encouraged by pentylenetetrazol (PTZ) after mild-TBI in male Sprague–Dawley rats. Mild-TBI was performed by the weight-drop method in male Sprague–Dawley rats. PTE model was developed by injecting PTZ (30+15+15 mg/kg, 30 min intervals, i.p.) 7 days after head trauma. After the development of posttraumatic seizures, the rats were treated with NAC (100 mg/kg), LEV (50 mg/kg), GBP (100 mg/kg), NAC+LEV and NAC+GBP intraperitoneally for 14 days. Seizures related to PTE were scored by video-EEG recording. Motor performance of the animals was also evaluated in the rotarod test. 50 mg/kg LEV and 100 mg/kg GBP reduced seizures related to PTE. LEV alone (p?=?0.009), but the administration of GBP+NAC (p?=?0.015) was more effective on PTE-related seizure control. However, GBP+NAC application adversely affected the fall latency in the rotarod test. In terms of trauma-related seizure control, there was no statistically significant difference between the use of prophylactic LEV and symptomatic LEV. LEV alone or the combination of GBP with NAC provides more effective seizure control in the PTE facilitated by PTZ. On the other hand, the use of prophylactic LEV did not have any extra effect on posttraumatic seizure development and control.

     

Comparison of vitamin E, L-carnitine and melatonin in ameliorating carbon tetrachloride and diabetes induced hepatic oxidative stress

This study aimed to investigate whether treatments with vitamin E, L-carnitine and melatonin can protect against CCl₄ and diabetes-induced hepatic oxidative stress. Hepatic oxidative stress was performed in rats through 50% v/v carbon tetrachloride (CCl₄) (1 ml/kg/3days, i.p.), and through diabetes mellitus induced by streptozotocin (STZ) (40 mg/kg, i.p.). Vitamin E (100 mg/kg/day, i.p), L-carnitine (300 mg/kg/day, i.p.) and melatonin (10 mg/kg/day, i.p.) were injected for a period of 6 weeks. Thereafter, changes in serum glucose level, liver function tests, hepatic malondialdehyde (MDA) content, hepatic reduced glutathione (GSH) content, hepatic superoxide dismutase (SOD) activity, and serum total antioxidant capacity (TAC) level were evaluated. In CCl₄-induced liver fibrosis, the efficacy order was melatonin > L-carnitine > vitamin E, while in STZ-induced diabetes, the efficacy order was vitamin E ≥ melatonin > L-carnitine. In conclusion, these data indicate that low dose of melatonin is more effective than high doses of vitamin E and L-carnitine in reducing hepatic oxidative stress induced by CCl₄ and diabetes. Moreover, the potent effect of vitamin E in ameliorating diabetes can be linked not only to the antioxidant actions, but also to the superior effect in reducing diabetes-induced hyperglycaemia. Meanwhile, potency of L-carnitine was nearly the same in CCl₄ and diabetes-induced liver damage.