Pre-Treatment Of Erythrocytes With Garlic Or Tea Tree Oil Promotes Oxidation Of The Peroxiredoxin 2 Protein And Makes The Cells Less Susceptible To Infection By Plasmodium Falciparum


Plasmodium falciparum, the causal organism of the most deadly form of human malaria, lacks catalase and glutathione peroxidase enzymes and thus is highly dependent on peroxiredoxin (Prx) enzymes for its defence against oxidative stress. In addition to its own five Prx enzymes, P. falciparum also uses the human Prx2 protein which it imports from the host erythrocyte. Here we have investigated the effects of pre-treatment of uninfected erythrocytes with increasing concentrations of garlic or tea tree oil on the redox/oligomerization state of the Prx2 protein and on the P. falciparum parasitemia in the erythrocytes. Both oils were shown to be able to disrupt the Prx2 redox state in pre-treated uninfected erythrocytes by promoting oxidised dimer formation. Garlic oil was a more potent promotor of the oxidation/inactivation of the Prx2 protein than tea tree oil. The results also showed that both oils promoted oxidation/inactivation of the Prx2 protein at the 2nd generation ring stage and also appeared to promote oxidation of other sulfhydryl group-containing proteins. Additionally, pre-treatment of uninfected erythrocytes with the test oils made the erythrocytes less susceptible to infection by P. falciparum at the 2nd generation ring stage (new infections). Garlic oil was more effective than tea tree oil in this respect. Thus, oxidation of the Prx2 protein might be involved in decreasing the susceptibility of pre-treated uninfected erythrocytes to infection by P. falciparum. These results suggest that garlic and tea tree oils could be used as antimalarial drugs