BACKGROUND: In our previous study, the aqueous extract of Channa striatus (family: Channidae) fillet (AECSF) showed an antidepressant-like effect in mice. However, the mechanism of the antidepressant-like effect is unknown.
AIM: The objective of this study was to explore the involvement of monoamines in the antidepressant-like effect of AECSF in mice.
MATERIALS AND METHODS: AECSF was prepared by steaming the fillets of C. striatus. The male ICR mice were pretreated with various monoaminergic antagonists viz., p-chlorophenylalanine (100 mg/kg, i.p.), prazosin (1 mg/kg, i.p.) and yohimbine (1 mg/kg, i.p.), SCH23390 (0.05 mg/kg, s.c.) and sulpiride (50 mg/kg, i.p.) followed by treatment with AECSF and tested in tail suspension test (TST). Two-way ANOVA with Tukey test were used at p < 0.05 for significance.
RESULTS: The pretreatments with p-chlorophenylalanine, prazosin and yohimbine, but not with SCH23390 and sulpiride, were able to reverse the antidepressant-like effect of AECSF in TST.
CONCLUSIONS: The antidepressant-like effect of AECSF may be mediated through the serotonergic and noradrenergic systems and not through the dopaminergic system.
Eurycoma longifolia Jack was investigated for sexual motivation activity in adult, middle-aged male mice and in retired breeders, using the modified open field and the modified runway choice methods. Each mouse received 500 mg/kg of one of 4 fractions of E. longifolia Jack, viz. chloroform, methanol, butanol, and water, whereas the mice in the control and yohimbine groups received 3 ml/kg of normal saline and 30 mg/kg of yohimbine daily respectively for 10 d. The results show a transient increase in the percentage of male mice responding to the right choice after chronic consumption of the fractions with 50 percent of the adult middle-aged male mice treated with E. longifolia Jack and yohimbine scoring the right choice after 8 and 5 days post-treatment respectively. In conclusion, this study has shown that E. longifolia Jack continues to enhance sexual motivation in adult, middle-aged male mice and in retired breeders.