Neurobehavioral effect of ethanol extract of Calyptrochilum emarginatum leaves in male Swiss mice

Abstract

Background

Calyptrochilum emarginatum is a medicinal plant used in traditional African medicine to address conditions such as convulsive fever, memory loss, malaria, dysmenorrhea, TB, and cough. This study aimed to look into the central effects of the ethanol extract of C. emarginatum leaves in mice.

Method

Ethanol extract of C. emarginatum leaves (EECEL) was obtained by macerating the dried, pulverized leaves in 70 % ethanol for 72 h, followed by filtration and concentration. Acute toxicity was assessed according to OECD guideline 423. Thirty male Swiss mice (18–22 g) were randomly assigned into five groups (n = 6): distilled water (10 mL/kg, p.o.), EECEL (50, 100, or 200 mg/kg, p.o.), and diazepam (5 mg/kg, i.p.). The following behavioral tests were conducted: open field test (novelty-induced rearing and grooming, locomotor activity), hole board test (sedative effect), Y-maze (working memory), and elevated plus maze (anxiety). Data were analyzed using one-way ANOVA followed by Tukey’s post hoc test in GraphPad Prism 8.4.2, with results expressed as Mean ± SEM.

Results

The administration of EECEL (100 and 200 mg/kg, p.o) resulted in a significant (p < 0.005) increase in rearing & grooming [F (4, 40) = 6.537; p = 0.0004], and locomotion [F (4, 20) = 114.2; p < 0.0001] compared to the control groups. EECEL (50–200 mg/kg) significantly [F (4, 20) = 9.317; p = 0.0002] increased head-dipping behavior in the hole board test compared to the control groups. EECEL (100–200 mg/kg) had a significant effect [F (4, 20) = 9.317; p = 0.0002] on working memory in the Y-maze, resulting in a significant increase compared to the control group. However, EECEL (50 mg/kg and 200 mg/kg) had a significant effect (p < 0.0001) on the index of open arm avoidance in the elevated plus maze.

Conclusion

The present findings suggest that the ethanol extract of C. emarginatum leaves (EECEL) may exert central stimulatory effects, as evidenced by increased novelty-induced rearing, grooming, head-dipping, and locomotor activity. These behavioral outcomes are indicative of heightened central excitability and exploratory drive. The study thus provides preliminary empirical support for the neurobehavioral relevance of C. emarginatum, a plant hitherto underexplored in neuropharmacological literature. Further investigative efforts are, however, required to delineate its mechanistic pathways, including potential interactions with specific neurotransmitter systems, as well as to evaluate sex-based responses to its administration.