Neuroprotective Effects of Chrysin Mediated by Estrogenic Receptors Following Cerebral Ischemia and Reperfusion in Male Rats.

INTRODUCTION: Ischemic stroke is one of the leading causes of morbidity and mortality worldwide. Neuroprotective strategies were reported to attenuate cognitive deficits after ischemic incidents. Here we studied the neuroprotective potential of chrysin in a rat model of cerebral Ischemia/Reperfusion (I/R) in the presence or absence of Estrogen Receptors (ERs). METHODS: Adult male Wistar rats were pretreated with chrysin (CH) (CH; 30 mg/kg; gavage; for 21 consecutive days) alone or with selective ERs antagonists (ERα antagonist MPP; ERß antagonist PHTPP; IP) or nonselective ERs antagonist (ICI182780; IP). Then, the bilateral common carotid arteries were occluded for 20 min, which was followed by 72 h reperfusion. Subsequently, cognitive performance was evaluated by Morris Water Maze (MWM) and shuttle box tasks, and afterward, their hippocampi were removed for ELISA assays and H&E staining. Oxidative indicators Malondialdehyde (MDA) and Glutathione Peroxidase (GPx), as well as inflammation mediators interleukin (IL)-1ß and tumor necrosis factor-alpha (TNFα), were measured using commercial kits. RESULTS: Results of the current study showed that the anti-oxidative and anti-inflammatory properties of CH are possible mechanisms that could improve cognitive deficits and prevent neuronal cell death following I/R (P<0.001). These effects were reversed by ICI182780 (P>0.05). Furthermore, when chrysin was co-treated with ERß antagonist, PHTPP showed a weak neuroprotective effect in I/R rats. However, these parameters were not significantly different when chrysin was combined with ERα antagonist MPP. CONCLUSION: Our data confirm that chrysin could potentially serve as a neuroprotective agent against devastating effects of cerebral I/R injury, which may be mediated via its interaction with ERs, especially ERß.

Effect of administration of vitamins C and E on fertilization capacity of rats exposed to noise stress.

The aims of this study were to evaluate the effects of administration of Vitamins C and E on fertilization capacity in rats exposed to noise stress. 40 adult male rats were randomly divided into 5 equal groups. Group 1 as controls who were not exposed to noise and groups 2-5 exposed to noise with 90-120 dB intensity and 300-350 Hz frequency from 7 pm to 7 am everyday for 50 days. Group 2 exposed to noise and did not receive Vitamins. Group 3 received vitamin C, Group 4 received Vitamin E. Group 5 received Vitamins C and E concomitantly. After 50 days, serum Follicle-stimulating hormone (FSH), Luteinizing hormone (LH) and testosterone were calculated. Then each rat was left with three female rats for mating. Pregnant females were sacrificed on the 19 th day of pregnancy and evaluated for the presence and number of viable, dead and absorbed fetuses. The level of FSH, LH and testosterone significantly decreased in rats exposed to noise (P < 0.05). By administration of Vitamins in groups 3-5 we observed that the level of hormones significantly increased in compared to group 2 (P < 0.05). The fertilization capacity of male rats in groups 3-5 significantly increased in compared to group 2 (P < 0.05). There was significant difference between groups 1 and 2 in case of fertilization capacity (P = 0.001). The data in this study strongly suggests a negative role for noise stress on level of FSH, LH and testosterone level and also fertilization capacity of male rats. To complement the information it is suggested that this research be done on human samples.

Time- and dose-dependent neuroprotective effects of sex steroid hormones on inflammatory cytokines after a traumatic brain injury.

Following a traumatic brain injury (TBI), excessive release of proinflammatory cytokines is the major cause of cerebral edema and neuronal loss. This study was designed to examine changes in concentrations of some proinflammatory cytokines-including interleukin-1 beta (IL-1ß), interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), and transforming growth factor-beta (TGF-ß)-in a rat model of TBI in which the animals were treated with different doses of estrogen or progesterone 6 and 24 h after the TBI. Adult female rats were divided into 14 groups. Hormones or vehicle were given intraperitoneally 30 min after a moderate TBI was induced by the Marmarou method. The levels of proinflammatory cytokines in brain were measured at 6 and 24 h after the TBI. A high dose of estrogen (E2) or a low dose of progesterone (P1) increased brain levels of IL-1ß 52.7% and 79.2% respectively at 6 h after the TBI. By 24h, IL-1ß levels in the brain were 27.5% and 27% lower following administration of estrogen low dose (E1) or E2, respectively. High-dose administration of progesterone reduced brain levels of IL-6 to 45.9% at 6 h after the TBI, and P1 and E1 treatment significantly decreased IL-6 levels at 24 h. Brain levels of TNF-α were 72.5% lower at 6 h after the TBI following P2 treatment and 48.5% higher at 24 hrs following treatment with E2. The levels of TGF-ß were also 3.37 times higher 24 h after the TBI following treatment with E1. Both doses of the hormones tested increases TGF-ß levels 6 h after the TBI. Based on our findings, we conclude that progesterone and estrogen influence the levels of proinflammatory cytokines either at the primary or secondary stages after a TBI. Accordingly, this study suggests a mechanism by which hormones reduce cerebral edema.

Co-administration of Grape Seed Extract and Exercise Training Improves Endothelial Dysfunction of Coronary Vascular Bed of STZ-Induced Diabetic Rats.

BACKGROUND: One of the known complications of diabetes mellitus is vascular dysfunction. Inability of the coronary vascular response to cardiac hyperactivity might cause a higher incidence of ischemic heart disease in diabetic subjects. It has been indicated that regular exercise training and antioxidants could prevent diabetic cardiovascular problems enhanced by vascular damage. OBJECTIVES: The aim of this study was to determine the effects of grape seed extract (as antioxidant), with and without exercise training on coronary vascular function in streptozotocin induced diabetic rats. MATERIALS AND METHODS: Fifty male Wistar rats weighing 200 - 232 grams were randomly divided into five groups of 10 rats each: sedentary control, sedentary diabetic, trained diabetic, grape seed extract (200 mg/kg) treated sedentary diabetic and, grape seed extract treated trained diabetic. Diabetes was induced by one intraperitoneal injection of streptozotocin. After eight weeks, coronary vascular responses to vasoactive agents were determined. RESULTS: The endothelium dependent vasorelaxation to acetylcholine was reduced significantly in diabetic animals; exercise training or grape seed extract administration partially improves this response. However, exercise training in combination with grape seed extract restores endothelial function completely. The endothelium independent vasorelaxation to sodium nitroprusside was improved by combination of exercise training and grape seed extract. On the other hand, the basal perfusion pressure and vasoconstrictive response to phenylephrine did not change significantly. CONCLUSIONS: The data indicated that co-administration of grape seed extract and exercise training had more significant effects than exercise training or grape seed extract alone; this may constitute a convenient and inexpensive therapeutic approach to diabetic vascular complications.

Exercise Training and Grape Seed Extract Co-Administration Improves Lipid Profile, Weight Loss, Bradycardia, and Hypotension of STZ-Induced Diabetic Rats.

BACKGROUND: Exercise Training (ET) and Grape Seed Extract (GSE) as an antioxidant have many positive effects on controlling diabetes mellitus and its complications. OBJECTIVES: This study aimed to determine the effects of GSE alone or combined with ET on body weight, plasma lipid profile, blood pressure, and heart rate in STZ-induced diabetic rats. METHODS: IN THIS STUDY, MALE WISTAR RATS WERE RANDOMLY ASSIGNED TO FIVE GROUPS: sedentary control, sedentary diabetic, trained diabetic, GSE treated sedentary diabetic, and GSE treated trained diabetic. ET was conducted on the treadmill daily for 8 weeks. One way ANOVA followed by LSD test was used for statistical analysis. RESULTS: Reduction of body weight, high density lipoproteins, heart rate, and systolic blood pressure and increment of total cholesterol, triglyceride, low density lipoprotein, and very low density lipoproteins were observed after STZ injection. Co-administration of GSE and ET had more positive effects on lipid profile compared to each method alone. In addition, GSE and ET modified heart rate partially, while their combination was more effective in improvement of heart rat in conscious rats. On the other hand, administration of ET or GSE alone did not affect systolic blood pressure and body weight, while their combination restored systolic blood pressure completely and improved body weight partially. CONCLUSIONS: The study findings indicated that ET combined with GSE had more beneficial effects compared to each one alone on the complications of STZ induced diabetes. This may constitute a convenient and inexpensive therapeutic approach to diabetic complications.

Effect of noise stress on count, progressive and non-progressive sperm motility, body and genital organ weights of adult male rats.

AIMS: It was decided to investigate the effect of noise pollution on the body weight, genital organ weights, and also on sperm parameters. SETTING AND DESIGN: It is a prospective study designed in vitro. MATERIALS AND METHODS: A total 20 adult male wistar rats were used in this study. All rats were divided into 2 equal groups (n = 10): (1) control group and (2) experimental group. Animals of the experimental group were exposed to noise for 50 days with an intensity of 90-120 db and frequency of 300 - 350 Hz for 12 hours daily. After 50 days, at first, body weights of all animals were recorded, and then they were killed. The right epididymides were removed and also, sperm concentration and motility were determined. Each organ was weighed separately on an electronic balance. STATISTICAL ANALYSIS USED: Data are reported as mean ± SD and percentage. The statistical significance of difference between the control and experimental groups was determined by the unpaired t-test. RESULTS: The weights of the testes, epididymes, seminal vesicle, ventral prostate were found to be significantly decreased in rats exposed to noise pollution when compared with the weights of the same organs obtained from control group (P < 0.05). There was a statistical difference of P < 0.05 between the 2 groups in terms of sperm concentration. CONCLUSIONS: It is concluded that noise pollution has the bad effects on sperm concentration and motility; therefore, it is supposed that homes and places of working must be build far away of noisy of factories and other places with noise.

Effects of treadmill running on mid-term memory and swim speed in the rat with Morris water maze test.

Previous studies involving exercise and memory showed that learning and memory were improved by exercise. This study was performed to find the effect of treadmill running on memory. Mid-term memory and swim speed were measured within 8 days. Twenty rats were divided into two groups, a control and a test group. Mid-term memory and swim speed were measured in the Morris water maze apparatus. Our results showed that treadmill running produced a significant enhancement on mid-term memory and swim speed in the test group, which may be mediated by specific molecular pathways.

Daily running promotes spatial learning and memory in rats.

Previous studies on exercise have shown that physical activity improves learning and memory. Present study was performed to determine the effects of acute, chronic and continuous exercise with different periods on spatial learning and memory recorded as the latency and length of swim path in the Morris water maze testing in subsequent 8 days. Four rat groups were included as follows: (1) group C, controls which did not exercise; (2) group A, 30 days treadmill running before and 8 days during the Morris water maze testing period; (3) group B, 30 days exercise before the Morris water maze testing period only; (4) group D, 8 days exercise only during the Morris water maze testing period. The results showed that chronic (30 days) and continuous (during 8 days of Morris water maze testing days) treadmill training produced a significant enhancement in spatial learning and memory which was indicated by decreases in path length and latency to reach the platform in the Morris water maze test (p<0.05). The benefits in these tests were lost in 3 days, if the daily running session was abandoned. In group D with acute treadmill running (8 days exercise only) the difference between the group A disappeared in 1 week and benefit seemed to be obtained in comparison with the controls without running program. In conclusion the chronic and daily running exercises promoted learning and memory in Morris water maze, but the benefits were lost in few days without daily running sessions in adult rats.

Daily running promotes spatial learning and memory in rats.

Previous studies have shown that physical activity improves learning and memory. Present study was performed to determine the effects of acute, chronic and continuous exercise with different periods on spatial learning and memory recorded as the latency and length of swim path in the Morris water maze testing in subsequent 8 days. Four rat groups were included as follows: 1- Group C (controls which did not exercise). 2- Group A (30 days treadmill running before and 8 days during the Morris water maze testing period). 3- Group B (30 days exercise before the Morris water maze testing period only) and 4- Group D (8 days exercise only during the Morris water maze testing period). The results showed that chronic (30 days) and continuous (during 8 days of Morris water maze testing days) treadmill training produced a significant enhancement in spatial learning and memory which was indicated by decreases in path length and latency to reach the platform in the Morris water maze test (p < 0.05). The benefits in these tests were lost in three days, if the daily running session was abandoned. In group D with acute treadmill running (8 days exercise only) the difference between the Group A disappeared in one week and benefit seemed to be obtained in comparison with the controls without running program. In conclusion the chronic and daily running exercises promoted learning and memory in Morris water maze, but the benefits were lost in few days without daily running sessions in adult rats. Key pointsDaily running influence on spatial memory.The velocity of learning can be influenced by running activity.Path length is important parameter for measuring the speed of learning.