Intervention of standardized ethanol leaf extract of Annickia polycarpa, (DC.) Setten and Maas ex I.M. Turner. (Annonaceae), in Plasmodium berghei infested mice produced anti-malaria action and normalized gross hematological indices.

Abstract Ethnopharmacological relevance Malaria is a global public health burden due to large number of annual infections and casualties caused by its hematological complications. The bark of Annickia polycarpa is an effective anti-malaria agent in African traditional medicine. However, there is no standardization parameters for A. polycarpa. The anti-malaria properties of its leaf are also not known. Aim of the study To standardize the ethanol leaf extract of A. polycarpa (APLE) and investigate its anti-malaria properties and the effect of its treatment on hematological indices in Plasmodium berghei infected mice in the Rane’s test. Materials and methods Malaria was induced by inoculating female ICR mice with 1.0 x 107 P. berghei-infected RBCs in 0.2 mL (i.p.) of blood. Treatment was commenced 3 days later with APLE 50, 200, 400 mg/kg p.o., Quinine 30 mg/kg i.m. (Standard drug) or sterile water (Negative control) once daily per group for 4 successive days. Anti-malarial activity and gross malaria indices such as hyperparasitemia, mean change in body weight and mean survival time (MST) were determined for each group. Changes in white blood cells (WBCs), red blood cells (RBCs), platelets (PLT) counts, hemoglobin (HGB) concentration, hematocrit (HCT) and mean corpuscular volume (MCV) were also measured in the healthy mice before infection as baseline and on day 3 and 8 after inoculation using complete blood count. Standardization was achieved by UHPLC-MS chemical fingerprint analysis and quantitative phytochemical tests. Results APLE, standardized to its total alkaloids, phenolics and saponin contents, produced significant (P 0.05) weight gain. Hematological studies revealed the development of leukocytopenia, erythrocytosis, microcytic anemia and thrombocytopenia in the malaria infected mice which were reverted with the treatment of APLE 50 – 400 mg/kg p.o. or Quinine 30 mg/kg i.m. but persisted in the negative control. The UHPLC-MS fingerprint analysis of APLE led to identification of one oxoaporphine and two aporphine alkaloids (1 – 3). Alkaloids 1 and 3 are being reported in this plant for the first time. Conclusion These results indicate that APLE possessed significant anti-malaria, immunomodulatory, erythropoietic and hematinic actions against malaria infection. APLE also has the ability to revoke deleterious physiological alteration produced by malaria and hence, promote clinical cure. These properties of APLE are due to its constituents especially, aporphine and oxoaporphine alkaloids.