Comparative effects of a valerian extract and single compounds on sleep and body temperature in mice evaluated by telemetry

Traditional use of Valeriana officinalis L. suggests sleep promoting properties, yet contemporary observations in clinical trials and rodent models using the extract and isolated compounds are contradictory [1,2]. We evaluated locomotor activity and body temperature of mice using telemetry to obtain evidence of sleep promoting effects. This method provides a reduced variable environment which improves upon previous methodologies. A 70% ethanolic extract of Valeriana officinalis root (250, 500, and 1000mg/kg) was administered orally and data recorded for 180 minutes thereafter in male C57BL/6J mice. Oral administration of valerian extract had no effect on locomotor activity and body temperature compared to vehicle. Zolpidem (5mg/kg, positive control) significantly decreased locomotor activity by 57% (activity counts after 30min; control: 492.1±41.8, zolpidem: 212.6±44.2; p<0.001) and body temperature by 0.57°C (ΔT_max at 18 minutes, control: 36.53±0.12°C, zolpidem: 35.96±0.13°C; p<0.01) whereas caffeine (5mg/kg, negative control) induced an increase in activity of 47% (activity counts after 30 minutes; control: 492.1±41.8, caffeine: 725.1±76.4; p<0.01) without affecting body temperature. In conclusion, telemetry is a simple, adequate method for the specific measurement of sleep promoting effects. The extract showed no significant difference to vehicle; yet, further studies on single compounds may help substantiate the use of Valeriana officinalis as insomnia treatment.

References: [1]Hattelstohl, M. et al. (2008) Phytomedicine 15:2–15.

[2] Fernández, S. et al. (2003) Pharmacol. Biochem. Behav. 77:399–404.