Evaluation of the sedative and anti-oxidative activity of Rauwolfia vomitoria methanol leaves extract using mature Swiss albino rats

There is growing recognition that many adolescents obtain insufficient and/or poor quality sleep, which is regarded both as an epidemic of sleep deprivation amongst adolescents and an important public health problem. Adolescents are thought to optimally require approximately nine hours of sleep per night. However, a meta-analysis found that 53% obtain less than eight hours of sleep on school nights, and 36% report difficulty in falling asleep. This study therefore evaluated the effects of Rauwolfia vomitoria in the treatment of insomnia as well as its anti-oxidative potentials. Rauwolfia vomitoria 1,600 g leaf powder was extracted using cold maceration in methanol for 72 hours with intermittent shaking. Phytochemical analysis, total phenolic content, acute toxicity study, invitro anti-oxidative studies and sedative activity of the extract were done using standard methods. The phytochemical analysis showed the presence of alkaloids, saponins, tannins, flavonoids, steroids and terpenoids. Mean total phenolic content was estimated as 120.95 ± 1.31 mgGAE/g. No mortality was observed in both phases of the acute toxicity test. The LD50 was greater than 5,000 mg/kg body weight. In the anti-oxidant assays, at doses of 0.8 and 1.6 mg/ml, the methanol extract was at the same range of percentage inhibition of free radicals with the standard drug. The extract also showed reduced mean sleep onset similar to that of diazepam but more potent at higher doses. In conclusion, this study indicated rapid, long-lasting and significant anti-oxidant and sedative activities of Rawoulfia vomitoria methanol leaves extract which was however dose dependent.