[Evaluation of anxiolytic effects of silymarin extract from Silybum marianum in rats]

Anxiety is a common psychiatric disorder affecting many people in the society and is associated with clinical symptoms such as tachycardia, sweating, shortness of breath, insensitivity. The objective of this study was to evaluate anxiolytic effects of sylimarin extract in wistar rats. Material and Methods: 35 male Wistar rats with a mean weight of 250 +/- 25grams were divided into 5 experimental groups [n=7]. Silymarin was purchased from Goldaroo company in Isfahan. The rats received sylimarin with different doses of 35, 70, 140 and 280 mg/Kg for two weeks. The control group received saline orally with the same volume. Then, using elevated plus maze [EPM], 30 minutes after treatment, the behavior of the experimental groups was compared to that of control group. Data were introduced into SPSS software and analyzed by variance analysis. According to the results of this study, sylimarin with the three doses of 35, 70 and 140 mg/Kg caused a statically significant decrease in anxiety, in comparison to the control group. Our data showed that silymarin seems to be a potential and effective anxiolytic agent and can be used for anxiety control

[Effects of amygdala cholinergic system on modulation of anxiety behaviors of rats by use of Elevated Plus Maze test]

Anxiety is a common psychological disorder in the society which can be accompanied by physiologic and behavior disorders. There is evidence that neurons and cholinergic receptors are involved in the neurobiology of anxiety. In the present study, we have investigated the effects of muscarinic and nicotinic receptors of cholinergic system in amygdala of rats on anxiety, by use of Elevated Plus Maze test. In this study the locations of amygdale in the rats were determined by stereotaxis method and leading cannulas were inserted into the same locations for drug injection into amygdala. The effects of muscarinic and nicotinic receptors of central amygdala for controlling anxiety in the rats were assessed by use of Elevated Plus Maz test. Bilateral intra amygdala injection of physostegmine [2 micro g/rat] decreased percentage of open arm time [OAT] and open arm entries [OAE] [p<0.05] which indicated an increase in the level of anxiety. However bilateral injection of the muscarinic receptor antagonist, pilocarpine [0.25, 0.5, and 1 micro g], did not show a significant change in anxiety-like behavior [p>0.05]. Bilateral administration of nicotine [1 and 2 micri g/rat] into central amygdala [intra-CeA] induced an anxiogenic effect, shown by decreases in the percentage of OAT and percentage of OAE [p<0.05]. Bilateral intra-CeA injection of mecamylamine [20, 30, 50 ng/rat], a selective nicotine acetylcholine receptor [nAChRs] antagonist led to a significant anxiolytic behavior in the rats [p<0.05]. The results of this study indicate the muscarinic and nicotinic receptors of amygdale have a role in controlling anxiety

Effects of Permethrin on sexual behaviour and plasma concentrations of pituitary-gonadal hormones in adult male NMRI mice

Pyrethroids are commonly used as insecticides for both household and agricultural purposes, and recently have been shown to have detrimental effects on endocrine system. Permethrin is a type I pyrethroid which is used widely in Iran. In the present study the effects of permethrin on sexual behavior and plasma level of PG [pituitary-gonadal] hormones of adult male mice were investigated. Mice received daily Intra peritoneal injection of permethrin [10, 15, 20 mg/kg] for 5 weeks. Using receptive females, permethrin-treated male mice exhibited reduced sexual behavior [i.e. decrease in the number of sniffing, following, mounting and mating]. The concentrations of plasma testosterone, LH and FSH were measured by means of ELISA method. Serum testosterone levels were reduced significantly [p<0.05] in the experimental group versus control group, whereas FSH and LH values were not altered significantly. The results of this study indicate permethrin can have detrimental effects on plasma testosterone level and sexual behavior. In regard to considerable use of this insecticide in Iran, it's necessary to restrain its use and extent of human contact to prevent hazards of this insecticide on human body tissues

[Anxiolytic effects of Valepotriates extracted from Valeriana officinalis L. in rats]

Anxiety is a common disorder attacking many people in the society and often accompanied by physiological sensations such as tachycardia, chest pain, shortness of breath, insensitivity, and so on. The purpose of present study was to characterize the putative anxiolytic-like effects of valepotriates [dichloromethane extracts of valerian] using the elevated plus maze [EPM] in rats. This was an experimental study carried out at Biology Department of Azad Islamic University in Karaj [Iran] in 2006. Valepotriates was dissolved in DMSO and orally administered at different doses to adult male Wistar rats, 0.5, 1.5 and 3 hours before behavioral evaluation in an EPM. Control rats were treated with an equal volume of DMSO. Data were evaluated using SPSS and variance analysis. Single treatment with valepotriates at two concentrations of 0.1, and 0.2 g/kg caused a statically significant increased time-spent and arm entries into open arms of EPM compared to control group [p<0.05]. However, animal's locomotor activity found to be unchanged. Based on our data, it seems that valepotriates to have a potential as an effective anxiolytic agent