Search

Context: Co-administration of amodiaquine with MAMA decoction (MD), an herbal antimalarial drug comprising the leaves of Mangifera indica L. (Anacardiaceae), Alstonia boonei De Wild (Apocynaceae), Morinda lucida Benth (Rubiaceae) and Azadirachta indica A. Juss (Meliaceae) was investigated. The practice of concurrent administration of herbal medicines with orthodox drugs is currently on the increase globally., Objective: The study was designed to investigate the possible enhancement of the antimalarial potency as well as possible herb-drug interaction resulting from concurrent administration of MAMA decoction with amodiaquine (AQ)., Materials and Methods: Combinations of MD with AQ were investigated in chloroquine (CQ)-sensitive Plasmodium berghei NK 65 in varying oral doses (mg/kg) at: sub-therapeutic [MD30 + AQ1.25], therapeutic [MD120 + AQ10] and median effective [MD40 + AQ3.8], using chemosuppressive and curative antimalarial test models. Secondly, P. berghei ANKA (CQ-resistant)-infected mice were orally treated with MD 120, 240, [MD120 + AQ10] and [MD240 + AQ10] mg/kg, using both models. The survival times of mice were monitored for 28 d., Results: ED50 values of MD and AQ were 48.8 and 4.1 mg/kg, respectively. A total parasite clearance of CQ-sensitive P. berghei NK65 was obtained with the therapeutic combination dose in the curative test giving an enhanced survival time. In CQ-resistant P. berghei ANKA-infected mice, [MD120 + AQ10] and [MD240 + AQ10] mg/kg gave comparable activities with AQ (10 mg/kg) in both models., Conclusion: The therapeutic combination dose gave total parasite clearance of CQ-sensitive P. berghei NK65, whereas none of the doses tested showed notable activity against CQ-resistant P. berghei ANKA.

The use of decoctions of different plant materials is common practice in antimalarial ethnomedicine in Africa. Scientific evaluation of such herbal combinations to verify the claims is important. The study has evaluated the antimalarial efficacy of MAMA decoction (MD), a multicomponent herbal preparation and its individual plant components, namely leaves of Morinda lucida Benth [Rubiaceae] (ML), Azadirachta indica A. Juss [Meliaceae] (AI), Alstonia boonei De Wild [Apocynaceae] (AB) and Mangifera indica L [Anacardiaceae] (MI) in Plasmodium berghei-infected mice. Each decoction was prepared by boiling the powdered leaf in water, concentrated in vacuo and freeze-dried. The acute toxicity of MD (LD50=3.8 g/kg) was determined using Lorke's method. The antimalarial activities of MD and its plant components were evaluated by oral administration of the freeze-dried extracts (15-240 mg/kg) using the early malaria infection test model. The established malaria infection test was used to evaluate MD (60-240 mg/kg) while amodiaquine [10 mg/kg] (AQ) and distilled water were employed as the positive and negative controls, respectively. From the early malaria infection test, the effective doses at 50 % (ED50) and 90 % (ED90) for MD, AB, AI, ML, MI and AQ were 43, 79, 140, 134, 208 and 3.9 mg/kg and 202, 276, 291, 408, 480 and 9.2 mg/kg, respectively. For the established infection test, MD (240 mg/kg) and AQ gave parasite clearance of 55 and 95 % on day 5 of treatment. MD possesses antimalarial activity and is relatively safe.