Hypnotic effect of Ocimum basilicum on pentobarbital-induced sleep in mice

Abstract EN

Background : Sleep disorders are accompanied by several complications, and currently used soporific drugs can induce unwanted effects such as psychomotor impairment, tolerance, amnesia, and rebound insomnia.

Objectives : The present study was carried out to investigate if Ocimum basilicum has a sleep-prolonging effect.

Materials and Methods : This work was an experimental study on 72 mice which were randomly divided into 9 groups: saline (control); diazepam (3 mg/kg, positive control); hydro-alcoholic extract (HAE) of Ocimum basilicum (25, 50, or 100 mg / kg); ethyl acetate fraction (EAF, 50 mg / kg); n-butanol fraction (NBF, 50 mg / kg); water fraction (WF, 50 mg / kg); and saline containing 10 % DMSO (vehicle for EAF and NBF).

All the test compounds were injected intraperitoneally (IP) 30 minutes before pentobarbital administration (30 mg/kg).

Duration and latency of pentobarbital-induced sleep were recorded.

Also, LD50 of HAE was determined and the cytotoxicity of HAE was tested on neural and fibroblast cells using the MTT assay.

Results: HAE increased the duration of pentobarbital-induced sleep at doses of 25, 50, and 100 mg/kg (P < 0.001).

The hypnotic effect of HAE was comparable to that induced by diazepam.

Similarly, WF, EAF, and NBF at 50 mg/kg could increase sleep duration.

The sleep latency was decreased by HAE (P < 0.01 - P < 0.001) and NBF (P < 0.001), but not by WF and EAF.

The LD50 value for HAE was found to be 2.4 g/kg.

HAE had no effect on the viability of neuronal PC12 cells and L929 fibroblast cells.

Conclusions : The present data demonstrated that Ocimum basilicum potentiates sleeping behaviors without any cytotoxicity.

The main component (s) responsible for the hypnotic effects of this plant is most likely a non-polar agent (s) which is found in NBF.

Isolation of the active constituents may yield a novel sedative drug.