In vitro evaluation of the effect of black tea decoction extract on Leishmania major promastigotes

Cutaneous Leishmaniasis is an endemic disease in some parts of Iran and parasites disease without an effective medical treatment.  In this study we attempted to evaluate the antileishmanial effects of the black tea decoction extract as herbal medicines. L. major promastigotes were cultured in RPMI-1640 medium enriched with 10% FCS in the presence of 10, 20, 30 and 40% of extracts. Parasites behavioral reaction and growth pattern was monitored after 0.5, 1, 5, 24, 48 and 72 hours post-seeding by counting fixed parasites in a haemocytometer chamber and observing their motility pattern and shape by invert microscopy. Parasite viability was evaluated by MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay.  The results indicated that the number of promastigotes in groups containing 10, 20, 30 and 40% extract had decreased after 24, 28 and 72 hours while normal growth was observed in the control group which was significantly different (p<0.05) in comparison with the treatment groups. This study indicated that black tea decoction extracts could effectively prevent the growth of L. major promastigotes in vitro.