Ex vivo Study of Antimalarial Activity of Canarium Odontophyllum Leaf Extracts Against Plasmodium Berghei NK65

Background: Malaria is a parasite that is transmitted to human through the bite of a female Anopheles mosquito. Every year human was exposed to the threat of malaria infection. This disease becomes more fatal as these parasites show resistance towards the drug available. Thus, searches for new antimalarial drug are crucial. This study was carried out to evaluate the antimalarial activity in Canarium odontophyllum leaf extracts (methanol, acetone and aqueous) against erythrocytes infected with Plasmodium berghei NK65 using Plasmodium Lactate Dehydrogenase (pLDH) Assay and SYBR green I fluorescence Assay. Method: Three types of solvents were used to extracts Canarium odontophyllum leaf according to increasing polarity index; acetone, methanol and aqueous. These extracts were made into eight-fold serial dilution; concentrations ranging from 0.00001μg / ml as the lowest concentration until 100 μg / ml as the highest concentration and further tested on Plasmodium berghei NK65 infected erythrocytes via ex-vivo. The IC50 (inhibition concentration) 50 readings were taken at the point of 5% parasitemia level and in the synchronization process. Both PLDH assay and SYBR green I fluorescence assay were being carried out simultaneously. Result: The One-way ANOVA showed that there is no significant difference between extracts at 5% parasitemia level, even so methanol was further tested on synchronization process as it showed the lowest reading of IC50 among the three extracts for PLDH assay and SYBR green I fluorescence assay respectively, (IC50 0.00045μg / ml, 0.002 μg / ml). For synchronization stages, the One-way ANOVA result showed there is no significant difference between stages of morphology. However, methanol extracts showed the most potent on schizont, (1.16x10-5 μg / ml ) and young trophozoite, (0.00195 μg / ml ) stages for each method respectively. Conclusions: All three extracts of Canarium odontophyllum leaf were effective on Plasmodium berghei NK65, however methanol showed most promising results and further research on the fractions were required for proper drug development. The Ministry of Higher Learning funded this project, Government of Malaysia, under the Fundamental Research Grant Scheme Code No. FRGS/2/2014/SG05/UKM/02/3.