Marijuana and ß-estradiol interactions on spatial learning and memory in young female rats: Lack of role of the G protein-coupled estrogen receptor (GPR30).

It has been shown that 17ß-estradiol (E2) hormone is an essential biological factor for increasing the sensitivity of women to drug abuse. Recent studies have shown a potential overlap between the molecular pathways of cannabinoids and ovarian hormones. The current study evaluated the interference between the marijuana and E2 effect on spatial learning and memory and the role of the G protein-coupled estrogen receptor (GPR30) in young female rats. The animals were separated into two main groups: intact-ovary and ovariectomized (OVX) rats. The latter group received intraperitoneal injections of E2, G-1 (GPR30 agonist), G-15 (GPR30 antagonist), marijuana, and different combinations of these substances for 28 days. Spatial learning and memory were evaluated by the Morris water maze (MWM) test. We also assessed the BDNF (brain-derived neurotrophic factor) concentration and the hippocampal level of GPR30. The results showed a significant reduction of spatial learning and memory in OVX rats compared to intact-ovary rats, which were restored by E2 replacement. Moreover, treatment with G-1 mimicked E2 effects on spatial learning and memory. Marijuana impaired spatial learning and memory in intact-ovary rats, while improved in OVX rats. We also found that treatment with M + E2 induced significant impairment in spatial learning and memory; however, treatment with M + G1 and M + G15 + E2 showed no significant difference. No significant differences in BDNF expression were observed in experimental groups. These results suggest that marijuana and E2 interact in their effect on spatial learning and memory in young female rats, but GPR30 seems to play no role in this interaction.

The effect of Elettaria cardamomum extract on anxiety-like behavior in a rat model of post-traumatic stress disorder.

Post-traumatic stress disorder (PTSD) is a debilitating psychiatric condition which develops in 6-8% of the general population. Current standard pharmacological treatments for PTSD cannot be widely used due to having various side effects. Nowadays, various pharmacological properties have been related to Elettaria cardamomum L. (family of Zingiberaceae). The present study aims to evaluate the efficacy of E. cardamomum methanolic extract on anxiety-like behavior in a rat model of PTSD. Adult male Wistar rats (200-250gr) were used in this study. The rats underwent single prolonged stress (SPS) or control and intraperitoneally received either saline or different dosages (200, 400, and 800mg/kg) of E. cardamomum methanolic extract before and after stress sessions. Moreover, open field, elevated plus-maze, and rotarod tests were used to evaluate locomotion and anxiety-like behavior in the rats. Findings demonstrated that E. Cardamomum methanolic extract, particularly at the dose of 400mg/kg, significantly (P<0.05) improved anxiety-like behavior in a rat model of PTSD, as examined by the open field, elevated plus-maze, and rotarod tests. Administration of E. cardamomum methanolic extract after stress might help to prevent the formation of anxiety-like behavior in the animals. However, further studies are requiredto clarify the exact mechanisms involved.

The Effects of Methanolic Extract of Melissa officinalis on Experimental Gastric Ulcers in Rats.

BACKGROUND: Melissa officinalis (MO) has potent antioxidant activity. Recent research has demonstrated the anti-ulcer properties of some medicinal plants through their antioxidant properties. OBJECTIVES: The aim of this study was to evaluate the effects of methanolic extracts of MO on experimental gastric ulcers in rats. MATERIALS AND METHODS: Male Wistar rats (200 - 250 g) were starved for 24 hours prior to the induction of gastric ulceration by either indomethacin (48 mg/kg/oral) or water immersion restraint (WIR) stress. Experimental rats received either ranitidine (25 mg/kg) or MO extract (150, 300 and 450mg/kg) orally 2 hours prior to WIR stress or indomethacin treatment, for the evaluation of their gastroprotective effects. The control group received the same volume of saline. Gastric lesions were scored according to the surface of lesions on the ulcer index. Superoxide dismutase (SOD) and glutathione peroxidase (GPX) were determined as measures of antioxidant defense, and malondialdehyde (MDA) was determined to measure tissue oxidation. RESULTS: MO extract (150 and 300 mg/kg) significantly decreased the ulcer index in both the indomethacin (1.3 ± 0.09 and 1.5 ± 0.19, respectively) and WIR stress groups (1.5 ± 0.17 and 1.5 ± 0.22, respectively), as compared to the control rats (2.5 ± 0.28) (P < 0.01). MO extract (450 mg/kg) significantly reduced ulcer index readings in WIR stress rats (1.8 ± 0.31 vs. 2.4 ± 0.15 in the WIR group), however, MO extract at a dose of 450 mg/kg did not prevent indomethacin-induced gastric ulceration (2.4 ± 0.26). There was no significant difference in the ulcer index for MO extract- (150 and 300 mg/kg) and ranitidine-treated rats (P > 0.05). Also, MO extract (150 and 300 mg/kg) significantly reduced MDA serum levels (0.69 ± 0.6 µmol/L and 0.85 ± 0.24 µmol/L, respectively, vs. 4.5 ± 1.9 µmol/L in the saline group) and significantly increased antioxidants' SOD activities (296.3 ± 146.4 U/mL and 561.4 ± 120 U/mL, respectively, vs. 190.2 ± 63.8U/mL in the control group) and GPX levels (8273 ± 3049 U/mL and 14574 ± 5012 U/mL, respectively), compared to the control (3236 ± 1699 U/mL). CONCLUSIONS: Our results showed that MO extract may have a gastroprotective effect against experimental gastric ulcers in rats. The exact mechanism has not yet been determined, but it may be due to enhancing enzymatic antioxidant defenses and inhibiting lipid peroxidation.

Efficacy of Melissa officinalis in suppressing ventricular arrhythmias following ischemia-reperfusion of the heart: a comparison with amiodarone.

OBJECTIVE: We aimed to assess the influence of Melissa officinalis (lemon balm), a well-known herbal drug with numerous applications in traditional and modern medicine, on cardiac conduction and susceptibility to lethal ventricular arrhythmia. MATERIALS AND METHODS: Forty-two male Wistar rats were divided into a control group (CTL), an M. officinalis group that received the aqueous extract of M. officinalis L. intraperitoneally (i.p.) at dosages of 50, 100, 200 and 400 mg/ml/kg, respectively, and an amiodarone group (Amio group) that received 30 mg/ml/kg i.p. of amiodarone. Heart ischemia/reperfusion was induced by the ligation and release of the left anterior descending branch of the left coronary artery. RESULTS: There were no statistical differences between the groups in the basal heart rate and blood pressure. PR, corrected QT (QTc) and QRS intervals increased in the M. officinalis and Amio groups. PR and QTc were statistically significant only in the Amio group and QRS was significant only in the group receiving 400 mg of M. officinalis (M400 group) in comparison with the CTL group. During the reperfusion period, the decrease in ventricular fibrillations was statistically significant in all groups (except the M400 group) when compared with the CTL group. The score of arrhythmia severity also decreased, but was statistically significant only in the Amio group (p < 0.05 vs. CTL group). CONCLUSIONS: Our findings suggest that M. officinalis extract has a mild protective effect against reperfusion-induced lethal ventricular arrhythmias in rats.

The effect of saffron consumption on biochemical and histopathological heart indices of rats with myocardial infarction.

This study was designed to assess the effects of saffron (Crocus sativus) on rats' heart with isoproterenol-induced myocardial injury. Animals were divided randomly into four groups: vehicle-control group (CTL); ISO group, administrated with Isoproterenol 85 mg/kg s.c.; saffron group; and finally combined Saffron + ISO group. Basal and final serum levels of heart troponin I, heart tissue antioxidants and histopathological indices were assessed in all groups. Isoproterenol administration significantly increased serum level of troponin I when compared to control group (3.46 +/- 0.77 vs. 0.53 +/- 0.35 ml in ng/ml, P < 0.001) and reduced significantly the glutathione peroxidase activity of heart muscle (1.63 +/- 0.21 vs. 4.01 +/- 0.64 nmol/mg protein, P < 0.05). The grade of heart muscle damages was severe in more than 70% of ISO group animals. Saffron + ISO group showed remarkably decreased intensity of tissue destruction and significantly decreased serum levels of heart troponin I, when compared to ISO group (1.25 +/- 0.23 vs. 3.46 +/- 0.77 ng/ml, P < 0.05). The level of glutathione peroxidase activity in Saffron + ISO animals did not have significant decline compared to saffron alone. These results suggest the protective role of saffron on ischemic hearts by biochemical and histopathological findings.