Potentiating Effects of Lactuca sativa on Pentobarbital-Induced Sleep

Document Type: Research article

Authors

1 Pharmacological Research Center of Medicinal Plants, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

2 1- Pharmacological Research Center of Medicinal Plants, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. 2- Department of Pharmacology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.

3 1- Pharmacological Research Center of Medicinal Plants, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. 2- Neurocognitive Research Center, School of Mashhad University of Medical Sciences, Mashhad, Iran.

Abstract

Traditionally, Lactuca sativa (lettuce) has been recommended for its hypnotic property.
The present study was planned to investigate sleep-prolonging effect of this plant. The hydroalcoholic
extract (HAE) of lettuce and its water fraction (WF), ethyl acetate fraction (EAF),
and n-butanol fraction (NBF) were administrated (IP) to mice 30 min before the pentobarbital
injection. Moreover, both in-vivo and in-vitro toxicity of the extracts were determined. The
quality of HAE and NBF was also evaluated using HPLC fingerprint. The HAE prolonged the
pentobarbital-induced sleep duration at dose of 400 mg/Kg. The NBF was the only fraction
which could increase the sleep duration and decrease sleep latency. The effects of NBF were
comparable to those of induced by diazepam. The LD50-value for HAE was found to be 4.8
g/Kg. No neurotoxic effect was observed either by HAE or by its fractions in cultured PC12
neuron-like cells. The results suggest that lettuce potentiates pentobarbital hypnosis without
major toxic effect. The main component(s) responsible for this effect is most likely to be nonpolar
agent(s) which found in NBF of this plant.

Keywords