Resistance Mitigating Effect of Artemisia Annua Phytochemicals against Plasmodium berghei ANKA and Plasmodium yoelii in Swiss Albino Mice

Malaria is a disease of global concern. Resistance of Plasmodium falciparum to drugs such as chloroquine and sulfadoxine-pyrimethamine is a major problem in malaria control. Artemisinin derivatives, particularly in combination with other drugs, are thus increasingly used to treat malaria, reducing the probability that parasites resistant to the components will emerge. Artemisinin resistance has recently been reported in the Thai-Cambodia border. The project was designed to demonstrate resistance-mitigating effects of phytochemical A. annua of Artemisia annua relative to pure artemisinin against the rodent malaria parasite Plasmodium berghei Anka and plasmodium yoelii. The in vivo experiments were done by inoculating the Swiss albino mice with the P. berghei ANKA parasite and P. yoelii and thereafter treated them with pure artemisinin and Artemisia annua phytochemicals. After 4 days parasitaemia was determined and the ED50 and the ED9O calculated and then the mice were passaged. The ED values got were utilized to determine the doses to be used for resistance development. The ED50 and ED90 got for artemisinin with P. berghei ANKA was 1.43 and 7.18 mg/kg. day respectively while the ED50 and ED90 got for the A. annua with P. berghei ANKA was 34.5 and 118 mg/kg. day respectively. The chloroquine resistant murine plasmodium (P. yoelii) values were as follows artemisinin ED50 and ED90 got was 11.63 and 29.8 mg/kg. day respectively. The efficacy of dihydroartemisinin was also determined in order to compare with artemisinin and the ED50 and ED90 got for DHA with P. berghei ANKA was 1.73 and 8.31 mg/ kg. day respectively. In order to determine resistance development the ED50 and ED90 were determined after every 10 cycles. This was compared with the values that had been obtained before exposure to the drug pressure. Relative index was calculated as final ED50 divided by the parental ED50. The results indicated that there was incremental increase in the Relative index with increase in cycles in both P. yoelii and P. berghei anka. Resistance obtained in the two murine plasmodium parasites was found to be transient.