St John's wort (Hypericum perforatum) diminishes cognitive impairment caused by the chronic restraint stress in rats.
ABSTRACT In this study we tested the hypothesis that St John's wort (Hypericum perforatum) may counteract stress-induced memory impairment. Object recognition test and Morris water maze were used to determine whether administration of H. perforatum (350 mg kg(-1) for 21 days), standardized to 0.3% hypericin content, protects against non-spatial and/or spatial memory impairments due to chronic restraint stress (2h daily for 21 days). A group of rats administered the exogenous corticosterone at the dose of 5 mg kg(-1) daily for 21 days, yielding its similar plasma levels as these observed in stress was run in parallel. In the first experiment all rats were tested for recognition memory in the object recognition test. On the following day, the animals were tested in open field and elevated "plus" maze to control for the contribution of respectively, motor and emotional effects of our treatments to the memory tests. In the second experiment, new group of stressed animals was tested for spatial memory in the water maze. We observed that H. perforatum prevented the deleterious effects of both chronic restraint stress and long-term corticosterone on learning and memory as measured in both, the object recognition and the water maze tests. The herb not only prevented stress- and corticosterone-induced memory impairments, but it significantly improved recognition memory (p<0.01) in comparison to control. These results suggest that H. perforatum has a potential to prevent stress memory disorders.
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ABSTRACT: Stress affects neuroendocrine stress response system, oxidative and nitrosative stress. Some reports claim that antioxidants and antistressors could attenuate these alterations. This study was realized to investigate antistress and antioxidant effects of Hypericum perforatum, Melissa officinalis, Valeriana officinalis and Passiflora incarnata extracts on repeated restraint (RS) in rats. Thirty-six rats were equally divided into six groups: A (control), B (only RS treated), C (H. perforatum + RS treated), D (M. officinalis + RS treated), E (V. officinalis + RS treated), F (P. incarnata + RS treated). Cortisol, lipid peroxidation, protein oxidation and nitric oxide (NO) levels escalated dramatically in group B compared to control, whereas almost all of them diminished remarkably again in groups C, D, E and F. Besides slight alterations of reduced glutathione content and glutathione-s-transferase, catalase activities were recorded between groups. Among vitamins only depletion of vitamin E was significant in Group B comparing to control. Interestingly administration of each plant extract led to increments of vitamins A and E even when compared to control. The results revealed that the aforementioned plant extracts has remarkable potentials to counteract repeated RS caused alterations of cortisol as well as oxidative and nitrosative stress biomarkers probably through their antistress, antioxidant and free radical defusing effects.
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ABSTRACT: The sedative and analgesic potential of Urena sinuata L. was investigated for the first time in this study. The crude methanol extract of Urena sinuata L. leaves was evaluated for its central nervous system (CNS) depressant effect using rodent behavioral models. Methanol extract of Urena sinuata at a dose of 400 mg/kg body weight, displayed a suppressive effect on motor activity, exploratory behavior (in hole cross and open field tests) and prolongation of thiopental induced sleeping time in mice. In the elevated plus-maze (EPM) test, the same dose of methanol extract significantly (p < 0.05) increased the time spent by the treated mice in EPM open arms. Analgesic potential of the extract was also evaluated for centrally acting analgesic activity using formalin induced licking response model and for peripheral analgesic action using acetic acid-induced writhing test and tail immersion tests. In formalin induced licking response model, a significant (p < 0.05) inhibition of pain compared to reference drug diclofenac sodium was observed. In acetic acid-induced writhing test and tail immersion test, the extract at 200 mg/kg body weight produced a significant reduction of writhing response and pain respectively. These results evidenced the potential sedative and analgesic effects of Urena sinuata leaves.International Food Research Journal 01/2014; 21((5)):: 2069-2075.
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ABSTRACT: Scoparia dulcis Linn. (SD) is a perennial herb that has been well studied for its antioxidant, anti-inflammatory, anti-diabetic and hepatoprotective effects. However, scientific information on SD regarding the neuropharmacological effect is limited. This study evaluated the sedative and hypnotic effect of the ethanolic extract of whole plants of Scoparia dulcis (EESD). For this purpose, the whole plants of S. dulcis were extracted with ethanol following maceration process and tested for the presence of phytochemical constituents. The sedative and hypnotic activity were then investigated using hole cross, open field, hole board, rota-rod and thiopental sodium-induced sleeping time determination tests in mice at the doses of 50, 100 and 200 mg/kg of EESD. Diazepam at the dose of 1 mg/kg was used as a reference drug in all the experiments. We found that, EESD produced a significant dose-dependent inhibition of locomotor activity of mice both in hole cross and open field tests (p<0.05). Besides, it also decreased rota-rod performances and the number of head-dipping in hole board test. Furthermore, EESD significantly decreased the induction time to sleep and prolonged the duration of sleeping, induced by thiopental sodium. Taken together, our study suggests that EESD may possess sedative principles with potent hypnotic properties.Evidence-based Complementary and Alternative Medicine 03/2015; 2015:1-6. · 2.18 Impact Factor