Combinations of stem bark powders of Enantia chlorantha and Uvaria chamae showed antimalarial activities in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: The stem bark of Enantia chlorantha Oliver (Annonaceae) and Uvaria chamae P. Beauv (Annonaceae) is widely used in African ethnomedicine for the treatment of malaria.

AIM OF THE STUDY: This study investigated the antimalarial activities of E. chlorantha and U. chamae stem bark powders in order to optimize their antimalarial activity. It also aimed to assess possible herb-drug interaction with orthodox antimalarial drugs.

MATERIALS AND

METHODS

The single and combined [1:1 (EU1); 1:2 (EU2) and 2:1 (EU3)] powders of E. chlorantha and U. chamae were reconstituted by suspending in propylene glycol (50%). Evaluation of the chemosuppressive and curative antimalarial models was carried out by oral administration of the single (6.25-200 mg/kg) and combined (6.25-25 mg/kg) powders on mice infected with the chloroquine-sensitive Plasmodium berghei NK65 and chloroquine-resistant Plasmodium berghei ANKA, respectively. Co-administration with artesunate-amodiaquine (ACT) and chloroquine was also assessed. The n-hexane extracts of the combined powders were analyzed individually by GC-MS.

RESULTS

At 200 mg/kg, E. chlorantha and U. chamae powders each gave significant chemosuppressive (86% and 83%) and curative (77% and 76%) activities, respectively. At 25 mg/kg, EU3 exhibited significant chemosuppressive activity (85.23%). At 6.25 mg/kg, EU3+CQ and EU3+ACT had chemosuppressive (77.61% and 75.87%) and curative (93.01% and 96.66%) activities, respectively. The GC-MS fingerprint of the combined powders revealed predominantly sesquiterpenes, oxygenated sesquiterpenes, fatty acid esters, and phytosterols.

CONCLUSION

Antimalarial activity was enhanced with combination of the powders while additive interaction was observed with the herb-drug combinations.