Behavioural studies on the ethanol leaf extract of Grewia carpinifolia in Wistar rats.

Background: Grewia carpinifolia is a plant commonly used in the tropics to manage various central nervous system (CNS) disorders. However, despite its widespread use no scientific work has been reported to validate these claims. Objectives: To evaluate the activity of G. carpinifolia as it affects behaviour using animal model. Methods: Twenty five adult Wistar rats were randomly divided into five groups (A-E). Group A served as control (given only distilled water), Groups B,C, D and E were administered with single oral dose of ethanol extract of G. carpinifolia leaf at 100, 200, 400 and 800 mg/kg body weight respectively for twenty eight days consecutively. Subsequently, open field test, negative geotaxis and hanging wire test were performed. Body and brain weights were measured and histological examination of the brain was also performed. Results: At the tested doses, the extract significantly increased the time spent on the hanging wire and decreased locomotor activity at 800 mg/kg. No significant difference was observed in body and brain weights of extract treated groups when compared with the control. No visible histological lesion was also observed. Conclusion: The plant extract may improve muscular strength at tested doses and possess CNS depressant activity at 800 mg/ kg.

Formulation and stability of topical water in oil emulsion containing corn silk extract

Purpose: To formulate the water in oil (W/O) emulsion of corn silk (CS) extract and to evaluate its stability at various storage conditions. Methods: Ethanol CS extract was prepared using maceration (cold) technique. A 4 % CS emulsion was prepared using varying concentrations of liquid paraffin, ABIL EM90 and water. The formulations were kept at 40 oC for 28 days and to screen out the less stable formulations. The remaining formulations were further stressed at 50 oC to choose the most stable formulation. The optimized formulation was evaluated for physical characteristics including phase separation, rheology and mean droplet size. The physical stability of the formulation was evaluated by monitoring these parameters over a period of 12 weeks at 8, 25, 40 and 40 oC, and 75 % RH. Results: The chosen formulation showed good resistance to phase separation on centrifugation under all storage conditions. Rheological behavior followed non-Newtonian pseudoplastic pattern at various storage conditions. Mean droplet size of freshly prepared formulation was 2.98 ± 1.32 µm and did not show significant (p < 0.05) changes at normal storage conditions (8 and 25 oC). Conclusion: The findings indicate that the developed CS extract W/O emulsion is stable and therefore may be suitable for topical use on skin as an antioxidant preparation.

Oral glutamate intake reduces acute and chronic effects of ethanol in rodents

Purpose: To assess the effects of oral glutamate intake on acute motor effects and chronic intake of ethanol in rodents. Methods: The acute effects of ethanol on motor function were studied in ICR mice by giving 2 or 6 g/kg of ethanol 2 h after distilled water or 2.5 g/kg glutamate per os. Thirty minutes after ethanol treatment, behavioral assays, including rotarod tests and foot print analysis were monitored. In chronic ethanol treatment, male Wistar rats were trained to consume ethanol-sucrose solution during a 2-h period daily, starting with 2 % ethanol/10 % sucrose and gradually increasing to 10 % ethanol/5 % sucrose solution over 56 days. After training session, the drug treatment phase was done for 10 days. The animals were force-fed 50 mg/kg/day topiramate or 2.5 g/kg/day glutamate 2 h before ethanol treatment sessions. Each day, ethanol intake, water intake, food intake and body weight were recorded. Results: Mice that received 2 or 6 g/kg of ethanol orally, showed a significant reduction in time on the rod in the rotarod test and a significant increase in both forelimb and hindlimb stride lengths when compared to control. Oral treatment with 2.5 g/kg of glutamate reversed the acute motor effects of ethanol. In chronic ethanol treatment, the intake of 10 % ethanol/5 % sucrose, accessible for 2 h, was significantly decreased in rats treated with either topiramate or glutamate. Conclusion: These results provide evidence that oral glutamate administration help to reduce the acute motor effects of ethanol in mice and ethanol intake in the chronic ethanol drinking rats.