Antimalarial and Antioxidant Potentials of Extract and Fractions of Aerial part of Borreria ocymoides DC (Rubiaceae).

Introduction: Borreria ocymoides (Burm F) DC is a weak, erect and decumbent herb that has several folkloric, ethno medicinal uses and is included in antimalarial preparations by some traditional healers. It is also used in treatment of ring worm, eczema and microbial infections. Objectives: To evaluate antimalarial activity of extract and fractions of Borreria ocymoides in Plasmodium berghei infected mice and to investigate their antioxidant activity using 1, 1-diphenyl-2-picryl-hydrazile (DPPH). Methods: The methanol extract of aerial part of B. ocymoides and the solvent fractions obtained from partition between organic solvents were assessed for antimalarial activity against chloroquine sensitive Plasmodium berghei NK65 infected mice using the suppressive and curative test procedures. Chloroquine (10 mg/ml) was used as positive control. The antioxidant activity was evaluated using DPPH radical scavenging ability and determination of total phenolic content. Results: The crude extract (250 and 500 mg kg-1) produced a dose dependent anti-plasmodial activity in the suppressive and curative tests. The chemo suppression activity was best in the ethyl acetate fraction (87.31%) and in the order ethyl acetate >dichloromethane > hexane > aqueous fraction. The DPPH radical scavenging activity of the extract increased with concentration. The antioxidant activity was less than ascorbic acid used as positive control. Oral administration up to 5 g/kg produced no noticeable deleterious effect 24 hours after dosing and up to 7 days afterwards. Conclusion: The results indicated that the extract has a potent anti-plasmodial activity against Plasmodium berghei and the activity seems to reside in the mid-polar fractions. Thus, the plant is a potential source of new antimalarial agents.