Antiplasmodial Properties, Toxicity and Novelty-Induced Behavior of a Formulation from Picralima nitida and Alstonia boonei

Abstract

Aims: This study aimed at investigating the antiplasmodial activities of the combination of Alstonia boonei De Wild (Apocynaceae) stem-bark and Picralima nitida (Stapf) T.&H.Dur. (Apocynaceae) seed, which is currently being produced as MAMA Syrup (MS) for malaria treatment in Nigeria. The study has also provided information on the CNS and sub-chronic toxicity effects of MS. This is to justify the folkloric use of the mixture of the two plants as an antimalarial remedy as well as the safety of MS. Methodology: Swiss albino mice of both sexes, (18-22 g), were used for the antiplasmodial experiments with the freeze-dried extractive from the decoction of the 1:1 mixture of the two plants against chloroquine-sensitive Plasmodium berghei NK65 strain. For the toxicity and novelty-induced behavioral (NIB) studies, twenty four rats were divided into four groups (n=6 per group) for three dose (150, 300 and 600 mg/kg) levels of MS and the vehicle (distilled water). The NIB was observed on days 1 and 30 of administration of MS and the vehicle. The animals were sacrificed on day 30 and blood harvested for biochemical assays. Results: The results of the antiplasmodial investigation showed that 12.5 mg/kg extractive of the plant mixture gave antiplasmodial activity equivalent to 82% of the activity of chloroquine (5 mg/kg). The NIB results showed that acute oral administration of MS had no significant effects while the sub-chronic administration caused a significant (P<0.05) increase in rearing but decrease in grooming behaviours, dose-dependently. The biochemical parameters were not affected by the administration of MS at all doses used. Conclusion: The extractive of the plant mixture possessed antiplasmodial activity while the oral sub-chronic administration of MAMA Syrup had central excitatory effects but no significant toxicity potentials in rats.