Pharmacognostic Screening and Antimalaria Activity of Methanol Bark Extract of Daniellia oliveri (ROLFE) Hutch. & Dalz. [Fabaceae] Extract on Plasmodium berghei Infected Mice

Introduction: Malaria parasite infection has remained a global leading cause of death and disability in which about 50% of the world population is estimated to be at risk, especially in low and middle income countries.

Aim: This research is designed to evaluate the pharmacognostic, phytochemical profile, and investigate its antimalarial activity by analysing different hematological indices of the methanolic bark extract of Daniellia oliveri, a plant belonging to the family of fabaceae.

Methods: The barks of this plants were collected, cleared, dried, pulverized and sequentially extracted with petroleum ether, n-hexane, ethyl acetate, methanol and aqueous using the soxhlet extractor. Acute toxicity studies (LD50) for the methanol bark extract was studied using standard method. Phytochemical and pharmacognostic screening was carried out using standard methods, its hematological analysis were investigated using standard methods. The antimalarial activity of the methanol bark extract Daniellia oliveri, was evaluated at different doses of 100, 200 and 400mg/kg using in-vivo models.

Results: The plant is a tall slender tree with a dark grey colour. The following extractive values were obtained petroleum ether (0.600±0.10), n-hexane (0.667±0.88), ethyl acetate (1.600±0.10), methanol (8.400±0.10) and aqueous (6.200±0.10).The methanol extract had the hightest extractive value and was found to be non-toxic at dose 5000mg/kg. The qualitative and quantitative phytochemical analyses reveals the presence of alkaloids (10.179±0.61), saponins (1.674±0.43), tannins (10.738±0.61), flavonoids (3.923±0.15), steroids (2.665±0.07), phenols (134.604±14.83), terpenoids (22.436±4.87), glycosides (14.485±0.08), reducing sugars (4.138±1.36), soluble carbohydrates but absence of cyanogenic glycosides The pharmacognostic parameters values were obtained as follows, total ash value (5.600±0.10), acid insoluble ash value (2.800±0.88), water soluble ash value (0.500±0.10), moisture content (13.933±0.12), bitterness value , foaming index (less than 100), swelling index (2.867±0.99).

Conclusion: This result has shown that the hematological analysis carried out exhibited significant improvement in PCV, RBC and Hb when administered the plant extract compared to the standard group. It exhibited significant increase in platelet and lymphocyte while reduction in neutrophil compared to the standard group. The increased hematological indices indicate a better transportation capacity of the red blood cells and this should be attributed to the antimalarial properties of the extract. Also, the white blood differential count indicates a boost in the immune system of the treated P. berghei infected mice. This study justifies the ethno-medicinal use of D. oliveri in the management of malaria.