Aim: Infections caused by protozoa of the genus Leishmania are major worldwide health problems with high endemicity in developing countries. The incidence of leishmaniasis has increased in the absence of a vaccine. Usual drugs for treatment of the disease have many side effects; therefore, there is an urgent need to find new effective alternatives. The plant kingdom is a valuable source of new medicinal agents. Methods: In this randomized, one-blind clinical trial, the in vitro leishmanicidal effects of Artemisia aucheri and Camellia sinensis on Leishmania major were evaluated. The methanolic extracts were prepared by percolation method. The extracts were dried and redissolved in PBS+DMSO 1% solvent. L. major cells treated with five concentrations (150, 300, 450, 600, and 750 µg/ml) of the extracts and an untreated control group were used in the study. The number of promastigotes in each concentration was calculated using a hemocytometer slide at time zero and at 24, 48, and 72 hours after being harvested. Results: Methanolic extract of A. aucheri inhibited the parasite multiplication at doses of 150, 300 and 450 µg/ml at 48 and 72 hours of culture. Doses of 600 and 750 µg/ml showed the same effect at 24, 48 and 72 hours of culture (P< 0.05). Methanolic extract of C. sinensis showed inhibition of parasite multiplication when administered at doses of 150, 300, 450, 600 and 750 µg/ml at 72 hours (P

Aim: Infections caused by protozoa of the genus Leishmania are major worldwide health problems with high endemicity in developing countries. The incidence of leishmaniasis has increased in the absence of a vaccine. Usual drugs for treatment of the disease have many side effects; therefore, there is an urgent need to find new effective alternatives. The plant kingdom is a valuable source of new medicinal agents. Methods: In this randomized, one-blind clinical trial, the in vitro leishmanicidal effects of Artemisia aucheri and Camellia sinensis on Leishmania major were evaluated. The methanolic extracts were prepared by percolation method. The extracts were dried and redissolved in PBS+DMSO 1% solvent. L. major cells treated with five concentrations (150, 300, 450, 600, and 750 µg/ml) of the extracts and an untreated control group were used in the study. The number of promastigotes in each concentration was calculated using a hemocytometer slide at time zero and at 24, 48, and 72 hours after being harvested. Results: Methanolic extract of A. aucheri inhibited the parasite multiplication at doses of 150, 300 and 450 µg/ml at 48 and 72 hours of culture. Doses of 600 and 750 µg/ml showed the same effect at 24, 48 and 72 hours of culture (P< 0.05). Methanolic extract of C. sinensis showed inhibition of parasite multiplication when administered at doses of 150, 300, 450, 600 and 750 µg/ml at 72 hours (P