Anticonvulsant Effect of Alcea aucheri on Pentylenetetrazole and Maximal Electroshock Seizures in Mice.

INTRODUCTION: This study was designed to investigate the possible anticonvulsant effect of acute administration of an aqueous extract of flowers of Alcea aucheri (EFA) in two in vivo seizure models. METHODS: Seizures were induced in male adult Swiss mice by administration of Pentylenetetrazol (PTZ) or Maximal Electroshock (MES). Mice were randomly subjected to receive saline, EFA (8.75-175 mg.kg-1), or diazepam intraperitoneally (i.p.) 15 or 30 min before PTZ injection. In another experiment, mice were treated (i.p.) with saline, EFA (8.75-350 mg.kg-1), or phenytoin 15 or 30 min before the MES test. Diazepam and phenytoin were used as reference drugs. RESULTS: EFA (175 mg.kg-1) significantly increased the PTZ-induced seizure threshold compared with the saline control group 15 min after its administration. In the MES test, the extract (35 mg.kg-1) increased the latency to onset of tonic Hind Limb Extension (HLE) (seizure activity) compared with the saline group 15 min after treatment. Also, 30 min after treatment, EFA (35, 70, and 175 mg.kg-1) increased the latency to onset of the seizure, decreased the duration of the seizure (70 mg.kg-1), and decreased seizure occurrence (350 mg.kg-1) compared with those of the saline group. At both time points, the extract at all doses significantly reduced the mortality rate compared with the saline group. CONCLUSION: These findings provide evidence of a possible anticonvulsant effect of A. aucheri in PTZ and MES seizure models in mice.

Anxiolytic-Like and Sedative Effects of Alcea Aucheri (Boiss.) Alef. Flower Extract in the Laboratory Rat.

The present study was conducted to investigate the possible anxiolytic and sedative of an acute administration and 4-day repeated dosing of an aqueous extract of flowers of Alcea aucheri (Boiss.) Alef. (EFA)in rats subjected to the elevated plus-maze (EPM), open-field, and horizontal wire tests. All drugs were administered intraperitoneally. Phytochemical screening confirmed the presence of phenolic compounds, flavonoids, and polysaccharides in the extract. Repeated dosing of EFA (at dose of 35 mg/kg) significantly increased percentage of time spent on open arms and of open arms entries, and also decreased percentage of time spent on closed arms and of closed arms entries; compared with saline control, 24 h after treatment. In addition, repeated dosing of EFA (at dose of 175 mg/kg) significantly increased open arm activity 48 h after treatment, versus saline group. This effect was also observed following acute administration of EFA at 175 mg/kg. In open field, acute administration of EFA at doses of 17.5, 35, 70, 175, 350, and 700 mg/kg induced a statistically significant and dose-dependent decrease in locomotor activity, compared with saline control. ED50 value for EFA-induced decrease in locomotor activity was 194 mg/kg. Furthermore, unlike diazepam; EFA didn´t decrease the percent of the rats grasping the wire. These data suggest that Alcea aucheri extract may have anxiolytic and sedative properties and some of the components in the extract such as phenolic compounds may have contributed to the observed effects.

Effects of Sodium Cromoglycate on Iranian Asthmatic Subjects Without Exposure to any Bronchoconstrictor agent.

Cromolyn sodium, a mast cell stabilizing agent, provides an immediate protective effect against the exercise-induced bronchoconstriction while being used before the exercise. However, cromolyn is ineffective in reversing asthmatic bronchospasm; it is used as a maintenance therapy and has a prophylactic role in chronic asthma. The purpose of this study was to determine the extent of change in baseline lung function tests following a single dose of cromolyn sodium in adult asthmatics. Forty volunteers (33 women and 7 men) with moderate to severe persistent asthma were randomly assigned to receive 20 mg cromolyn, 40 mg cromolyn or cromolyn-placebo. The percent of improvement in lung function parameters was compared among the groups, during 1 h of inhalation. Low dose of cromolyn induced more improvement in most lung function parameters such as forced expiratory flow volume in one second, forced vital capacity and peak expiratory flow compared with other groups. After 15 min, the improvement percentage of baseline forced expiratory flow volume in one second was 3.35 ± 1.5, for sodium cromoglycate-20 mg group compared with 0.98 ± 1.43 and - 0.68 ± 1.2 for sodium cromoglycate-placebo and sodium cromoglycate-40 mg, groups respectively. However, the differences between means were not significant. Furthermore, based on the definition of American Thoracic Society (ATS) for a "significant post-bronchodilator response" developed in a few patients 15 min after the inhalation of 20 mg cromolyn sodium. It is suggested that probably the inhalation of 20 mg of cromolyn sodium could immediately improve the lung function in few adults with asthma.

Role of nitric oxide and prostaglandin systems in lithium modulation of acetylcholine vasodilation.

The mechanism of lithium action, an effective treatment for bipolar disease, is still unknown. The present study examined the role of nitric oxide (NO) and prostaglandin systems in lithium modulation of acetylcholine in mesenteric vascular bed of rats by cannulating superior mesenteric artery. Acetylcholine (ACh) or sodium nitroprusside was injected under constant controlled flow induced by phenylephrine; therefore, changes in perfusion pressure reflect changes in resistance. Although 0.5 mM or 1 mM lithium-pretreatment of vascular bed causes reduction in ACh-response, 1.5 mM lithium induced no changes and 2 and 2.5 mM lithium potentiated ACh-induced mesenteric vascular bed relaxation compared to control group. Pretreatment of vascular bed with L-NAME or indomethacin decreased ACh-induced relaxation in 2 concentrations of 0.5 and 2 mM of lithium. The vasorelaxation response to sodium nitroprusside, the NO donor, was not different among lithium groups (0.5 and 2 mM) and controls. In conclusion, there is a dual modulation of endothelium-dependent relaxation, including an inhibitory effect at lower dose and a stimulating effect at higher dose of lithium in rat mesenteric vascular bed. NO synthesis or cyclooxygenase inhibition decreased vasorelaxation in both lower and higher doses of lithium, suggesting a role for NO and prostaglandin in this effect.

The effect of lithium chloride on morphine-induced tolerance and dependence in isolated guinea pig ileum.

The chronic use of opioids is often accompanied by the development of tolerance and/or dependence upon these agents due to the adaptive changes in the response of the subject to the agent. On cellular level, these phases of altered responsiveness have been shown to be the sequelae of a combination of multiple independent components acting in concert. Changes in the number, affinity, or membrane trafficking of opioids receptors, the coupling of receptors to G-proteins or in associated second messenger systems have been implicated in underlying the aforementioned phenomena. Several observations have been shown that lithium is able to contradict the expected response in animals pre-treated with morphine. These facts clearly manifest the involvement of lithium in at least one of the diverse pathways that lead to morphine dependence and/or tolerance. The aim of the present study was to investigate the effect of lithium on acute morphine-induced tolerance and dependence in an in vitro model of isolated guinea pig ileum which has been extensively used for the assessment of these effects of opioids. Morphine inhibited electrically stimulated twitch of ileum in a concentration-dependent manner (pD(2)=7.27+/-0.16). Tolerance to this effect was induced by the incubation of ileum with 2xIC(50) of morphine for 2 h that induced a degree of tolerance of 14.7. The co-incubation of ileum with morphine along lithium chloride (1 mM) reduced the degree of tolerance significantly (P<0.001) and restored the sensitivity of ileum to the morphine inhibitory effect. Lithium chloride can also reduce the expression of tolerance to morphine significantly (P<0.01). Dependence was induced by incubation with 4xIC(50) of morphine for 2 h and was assessed based on naloxone-induced contractions (10(-5 )M). Lithium chloride (1 mM) can attenuate the development but not the expression of dependence to morphine as shown by the significant decrease in naloxone-induced contractions (P<0.05). These results suggest that lithium chloride can reduce the development and expression of acute tolerance to and development of dependence on morphine in the myenteric plexus of guinea pig ileum.