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 antimalaria
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 × 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)
dose-dependent clearance of mean hyperparasitemia of 22.78 ± 0.93% with the minimum parasitemia level of
2.01 ± 0.25% achieved at 400 mg/kg p.o. on day 8. Quinine 30 mg/kg i.m. achieved a minimum parasitemia
level of 6.15 ± 0.92%. Moreover, APLE (50–400 mg/kg p.o.) evoked very significant anti-malaria activity of
89.22–95.50%. Anti-malaria activity of Quinine 30 mg/kg i.m. was 86.22%. APLE also inverse dose-dependently
promotes weight gain with the effect being significant (P < 0.05) at 50 mg/kg p.o. Moreover, APLE dosedependently
increased the MST of malaria infested mice with 100% survival at 400 mg/kg p.o. Quinine 30
mg/kg i.m. also produce 100% survival rate but did not promote (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.
