Hydroalcoholic extract of Myrtus communis can alter anxiety and sleep parameters: a behavioural and EEG sleep pattern study in mice and rats

Figures & data

Figure 1. Effects of the M. communis extract on open field parameters: (a) Velocity, (b) distance moved, (c) number of rears. While the anxiety parameters were significantly reduced by all applied doses (**p < 0.01 and ***p < 0.001), flumazenil could not reduce those effects (ns: not significant, p > 0.05). Values represent mean ± SEM (n = 10 mice/group).

Figure 2. Effects of the M. communis extract in pentobarbital induced loss of righting reflex. The extract induced sleep at dose 200 mg/kg (**p < 0.01 and ***p < 0.001). The response was not reduced by co-injection of flumazenil (ns: not significant, p > 0.05). Values represent the mean ± SEM (n = 10 mice/group). The Y-axis is shown in logarithmic scale.

Figure 3. Muscle relaxation effects of diazepam, M. communis extract and their combination with flumazenil in grip strength test. The results showed significant muscle tone reduction by the extract (200 and 400 mg/kg) as well as diazepam (**p < 0.01 and ***p < 0.001) while, flumazenil could not diminish the myorelaxant effects (p > 0.05). Values represent mean ± SEM for the applied force to pull on from the instrument.

Table 1. Effects of M. communis extract (200 mg/kg) and diazepam (2 mg/kg) on EEG spectra.

	Saline	Myrtle (200 mg/kg)	Diazepam (2 mg/kg)	p Value (F test)
Total sleep %	42.2 ± 1.5	85.3 ± 6.2***	96 ± 0.5***	<0.001
NREM %	48.2 ± 5.2	82.5 ± 7.6 **	90.2 ± 1.5***	<0.05
REM %	4.3 ± 1.7	2.4 ± 0.5*	3.5 ± 0.2	<0.01

Tukey’s post-test revealed that administration of M. communis extract (200 mg/kg) elevated total sleep as well as NREM sleep time in the tested rats (***p < 0.001 and **p < 0.01, respectively). Diazepam did not alter REM% (p > 0.05), while shortening of REM sleep by the extract was significant but weak (*p < 0.05).