Journal of Natural Remedies

V. S. Nade , L. A. Kawale , S. Dwivedi , A. V. Yadav

Abstract

Objective: To investigate the effect of the methanolic extract of Hibiscus rosa sinensis ischolar_mains (H. sinensis) on the central nervous system in mice and rats. Materials and methods: The methanolic extract of H. sinensis was studied on pentobarbital-induced sleeping time, elevated plus maze, hole board test, foot shock-induced aggression, haloperidol-induced catalepsy, lithium-induced head twitches, locomotor activity, acetic acid-induced writhing and hot plate analgesiometer at various doses (50 - 200 mg/kg), intraperitoneally for sedative, anxiolytic, antipsychotic, muscle relaxant and analgesic activities. Results: The extract prolonged pentobarbital-induced sleeping time indicating sedative effect. The extract increased the time spent in open arms and the number of head dips in elevated plus maze and hole board test respectively demonstrating anxiolytic activity. H. sinensis decreased number of fights in foot shock-induced aggression and potentiated haloperidol-induced catalepsy in dose dependent manner showing antipsychotic effect. The extract significantly inhibited head twitches induced by lithium suggesting its inhibitory effect on serotonergic system. The H. sinensis significantly decreased the locomotor activity in dose dependent manner. The extract showed potential analgesic activity in acetic acid-induced writhing and hot plate analgesiometer. The H. sinensis attenuated the behavior mediated by the dopaminergic and serotonergic system and potentiated the GABAergic actions. Conclusion: The results suggest that the methanolic extract of Hibiscus rosa sinensis has potential neuropharmacological activities.

Keywords

Hibiscus Rosa Sinensis, Sedative, Anxiolytic, Antipsychotic, Analgesic, Catalepsy

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V. S. Nade , A. V. Yadav

Abstract

The present study was designed to investigate the neuroprotective effect of Hibiscus rosa sinensis L. in aluminuminduced neurotoxicity in rats. The animals were treated with aluminium chloride (4.2 mg/kg, p.o) for 21 days to induce oxidative stress. The methanolic extract of Hibiscus rosa sinensis (HRS - 100, 200 and 300 mg/kg/day, p.o, for 21 days) was administered 30 min before aluminum. The elevated plus-maze paradigm was used to assess the effect of HRS on aluminum-induced memory impairment. Animals were sacrificed on 21st day, brains were isolated and biochemical estimations were performed. The aluminium treated group showed significant increase in transfer latency (TL) on day 20th and 21st indicating impairment of memory. Administration of HRS (100 - 300 mg /kg, p.o) significantly (p < 0.01) reversed the memory impairment. Biochemical analysis of brain revealed that the chronic administration of aluminium significantly increased lipid peroxidation and decreased levels of catalase (CAT) and glutathione reductase (GSH), an index of oxidative stress process. Administration of extract significantly (p < 0.01) attenuated the lipid peroxidation; and reversed the decrease in brain CAT and GSH levels (p < 0.01). The superoxide dismutase (SOD) levels were increased after aluminium treatment which was normalized by HRS (p < 0.01). The results strengthen the oxidative stress hypothesis of aluminium- induced neurotoxicity and suggest the beneficial role of HRS in the management of Alzheimer's disease and oxidative stress. Cognitive-enhancing activity of HRS may be exerted through antioxidant mechanism.

Keywords

Hibiscus rosa sinensis, Aluminium, Elevated Plus-maze, Lipid Peroxidation, Oxidative Stress

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