Sedative Effects of Hot Flower Infusion of Nyctanthes avbo-tristis on Rats

摘要

Hot infusion of Nyctanthes arbo-tristis Linn. (Oleaceae) flowers are used often by some elderly Sri Lankan Buddhist monks as a potential sedative. However, in Ayurve-dic, traditional and folkloric medicine of Sri Lanka, no such implication has been made regarding therapeutic activity of these flowers. The aim of this study was to investigate the sedative potential of N. arbo-tristis flowers in rats using the hole-board technique. A hot flower infusion was made as used by the monks in different concentrations (3.7, 7.5, 12.5, or 18.7mg/kg) and was orally administered. Sedative potential was assessed 2h post-treatment. The infusion had a moderate dose-dependent conscious sedative activity in male but, surprisingly, not in female rats. The infusion was well tolerated (in terms of overt toxic signs, liver or kidney functions) even following subchronic treatments and also did not show any overt signs of dependence (classical signs of withdrawal reactions). Sedation appears to result mainly by antioxidant, membrane stabilizing, and by yet undiscovered mechanisms of sedative actions of anthocyanin, a flavonoid, in the flower.