Subchronic administration of Parastar insecticide induced behavioral changes and impaired motor coordination in male Wistar rats.

Parastar is an insecticide formulation of lambda-cyhalothrin and imidacloprid largely used for crop protection in North West Region of Cameroon. In the present study, we evaluated the behavioral activities and motor function of Wistar male rats after subchronic treatment with the pesticide formulation. To this end, three groups of adult rats were administered Parastar at doses 1.25, 2.49 and 6.23 mg/kg, respectively, for 35 days. A control group was included and received distilled water. At the end of the treatment, the animals were submitted to behavioral and functional tests (open field test, elevated plus maze test, light-dark box test, forced swimming test, tail suspension test, beam-walking test, grid suspension test and wire hang test) for estimation of anxiety, exploration, depression and motor coordination. Results revealed that Parastar, at the higher doses tested, 2.49 and 6.23 mg/kg, induced anxiogenic-like pattern behavior in rats in all behavioral assays including open field test (total distance moved, total lines crossed, frequency and total time in center square were all reduced), elevated plus maze (decreased total time spent in open arms and the number of entries in open arms of the elevated plus maze), and light-dark box (the dark box duration increased, while light box duration time and frequency of transition between dark and light box decreased). Treatment with 2.49 and 6.23 mg/kg Parastar increased the immobility time of animals in both forced swimming test and tail suspension test. The insecticide induced decrease in the distance traveled, foot slip and number of turns of animals in the beam walking test. Parastar also decreased the animal suspension time in both grid suspension grip-strength test and the wire hang test. Taken altogether, these results suggest that subchronic administration of Parastar at the doses of 2.49 and 6.23 mg/kg induced anxiety-like and depressive-like behavior as well as impaired motor coordination and muscle strength in male rats.

Ejaculatory activities of Allanblackia floribunda stem bark in spinal male rats.

CONTEXT: Medicinal plants have become a great source of relief for more 70% of the population in developing countries where access to modern medicine is very limited. Some of these plants are used as aphrodisiac agents. The stem bark of Allanblackia floribunda Oliver (Clusiacea) has been used in Cameroon as an aphrodisiac. OBJECTIVE: This study was designed to assess the effects of Allanblackia floribunda aqueous and ethanol extracts and their potential mechanism on fictive ejaculation in spinal male rats. MATERIALS AND METHODS: Electromyographic activities of the bulbospongiosus muscles were recorded in 24 groups of spinal rats after intravenous administration of aqueous and ethanol extracts (2.5, 10, 20, 40 or 60 mg/kg) from the stem bark of A. floribunda in the presence or absence of dopamine (60 mg/kg). Furthermore, electromyographic activities of the bulbospongiosus muscles were recorded in five groups of spinal rats pre-treated orally during 8 d with extracts (150 and 300 mg/kg) in the presence of dopamine. RESULTS: Sequential treatments of rats with extracts significantly decreased the occurrence of ejaculation induced by dopamine up to 88.94% inhibition. The oral pre-treatment with both extracts significantly decreased the ejaculation induced by dopamine with the highest inhibition of 89.79%. DISCUSSION AND CONCLUSION: Two extracts of A. floribunda used in this study had inhibitory activities on ejaculation. The inhibitory effect of A. floribunda extracts on fictive ejaculation in rat may be directly mediated through dopaminergic pathways. Inhibition of ejaculation caused by these extracts could support its use in patients suffering from rapid ejaculation.