[Effects of ascorbic acid on the amplitude of ventral tegmental area field action potential in morphine-exposed rats [an electrophysiology study]]

Evidences have indicated that the Ventral Tegmental Area [VTA] is the major source of dopamine [DA] neurons projecting to cortical and limbic regions involved in cognitive and motivational aspects of addiction. Also, studies have indicated that the Ascorbic acid [vitamin C] can reduce the dependency symptoms of opioids such as morphine via effect of activity on dopaminergic neuron in VTA. For this reason, the aim of this study was to assess the effects of ascorbic acid on the amplitude of Ventral Tegmental Area field action potential in morphine-exposed rats. Forty male Wistar's rats were used in this experimental study conducted at Yasuj University of Medical Sciences in 2010. Animals were randomly divided into four groups after electrode implantation and recovery period: 1. No- Vit C and No-Addicted group [nVitC.nA] 2. Vit C and No-Addicted group [VitC.nA] 3. No- Vit C and Addicted group [nVitCA] 4.Vit C and Addicted [VitC.A], The Vit C groups received 500 mg/kg of Vit C during 20 days. For addicted groups morphine was administrated once daily for 20 days. In the 20[th] day, the field potential recording was accomplished. Two-way ANOVA was used for data analysis followed by the Tukey test for post hoc analysis. Results were considered significant at P<0.05. This study shows the exposure to morphine declined the power of Delta and Beta bands [p<0.05] and Vit C solely enhance power of Theta and Beta [p<0.05, p<0.001] in VTA nuclei. Furthermore, Vit C could alter power of some bands which were affected by morphine. Therefore, it seems that Vit C has an increasing effects on them [p<0.05]. Although the effect of Vit C on power of the VTA bands is not well known, but it is supposed that this phenomenon can be related to alteration in activity of dopaminergic neuron in the brain

hypoglycemic effects of a hydro-alcoholic extract from Securigera securidaca seeds on induced diabetis in male rats

Diabetes mellitus is a metabolic disorder of carbohydrates, lipids and proteins caused by deficiency or lack of insulin. The side effects of chemical drugs have increased the requirement to use of medical plants with fewer complications than that of the chemical drugs. Securigera securidaca is one of the medical plants traditionally used. This medicine has antiepileptic, diuretic, hypotensive and hypoglycemic effects. This study was aimed to evaluate the hypoglycemic effect of hydro-alcoholic extract of S. securidaca seeds on streptozocine induced diabetic rats. In this experimental study, a total of seventy Wistar albino male rats were randomly divided into seven groups. Diabetes was induced via intravenous injection of streptozocine [45mg/kg]. Then, the extract of Securigera securidaca seed was administrated orally in dosage of 500, 1000 and 2000 mg/kg in the mice. The blood glucose was measured before and one, two and three weeks after the administration of the extract. Using statistical methods, [Student t test, paired t test and ANOVA], the data were analyzed. Compared with the control group, Streptozocine significantly increased the blood glucose of the test group [p<0.001]. Doses of 500 and 1000 mg/kg of S. securidaca extract had no significant effect on blood glucose after two weeks. However, dose of 2000 mg/kg significantly decreased the blood glucose [p<0.001]. The extract had no significant effect on normal blood glucose in the rats. The findings showed that the extract of S. securidaca seed decreased the blood glucose in streptozocine induced diabetic rats dose-dependently. Therefore, it may be useful in diabetic patients

[Evaluation of the effect of hydroalcoholic extract of citrullus colocynthis in normoglycemic and streptozocine [STZ] diabetic male rats]

Adverse side effects of chemical drugs for treatment of diabetes persuaded the using of medical plants. Citrullus colocyn this is a plant which has been used traditionally for treatment of diabetes. The purpose of this study was to evaluate the effect of hydroalcholic extract of Citrullus colocynthis fruit on normoglycemic and streptozocine induced diabetic rats. 45 male Wistar rats weighing, 250-350 gr, have been selected and randomly divided in seven groups. Group 1 without any drugs usage, group 2 that received normal saline [IV] and distilled water [oral], group 3 received only streptozocine [IV], group 4 received only the extract of Citrullus colocynth is [1000 mg/kg], groups 5, 6 and 7 received 500, 1000 and 1500 mg/kg of Citrullus colocynthis extract after injection of STZ and induction of diabetes. Diabetes was induced by intravenous injection [45 mg/kg] of STZ. Blood sampling was provided directly from animal heart and blood sugar was measured. The collected data were analyzed by SPSS software using students t-test and ANOVA. Mean of normal blood sugar in control group was 156.5 +/- 15.7 mg/dl which defined as normal blood sugar. Streptozocine significantly increased blood sugar [p<0.05]. The Citrullus colocynth is extract with 500 mg/kg dosage has not significantly reduced the blood sugar but is dosage of 1000 and 1500 mg/kg significantly decreased the blood sugar in a dosedependent mode [p<0.05]. also showed that the extract in dosage of 1000 mg/kg did not have a significant effect on normoglycemic animals. Results of this study indicate that the extract of Citrullus colocynthis fruit dose-dependently reduced the blood glucose level in streptozocine-induceddiabetic rats but did not have significant effect on normal blood sugar