Experimental Aspects: Diagnostics and Therapeutics. Antileishmanial activity of green tea (Camelia sinensis) catechins against Leishmania (Leishmania) amazonensis and Leishmania (Viannia) braziliensis

BARROSO, PAOLA ANDREA; MARCO, JORGE DIEGO; KORENAGA, MASATAKA; HASHIGUCHI, YOSHIHISA

Studies on New and Old World Leishmaniasis and their transmission, with particular reference to Ecuador, Peru, Argentina and Pakistan

Kyowa Printing & Co. Ltd.

Lugar: Kochi, Japan; Año: 2007; p. 104 - 110

The anti-leishmanial efficacy of green tea catechins (GTC) was determined in vitro against Leishmania (Leishmania) amazonensis and L. (Viannia) braziliensis. Parasites and J774.1, a murine macrophage cell line, were cultured in complete RPMI medium at 23ºC and 37°C, 5% CO2 respectively. MTT assay was used to assess the effects of GTC on the viability of promastigotes and J774.1 cells. On the other hand, the activity of GTC against intracellular amastigotes was determined through IC50. In order to compare the toxicity of GTC on intracellular amastigotes and J774.1, the selectivity index ratio (SIR= IC50 J774.1/IC50 leishmania) was also calculated. When the GTC were tested in promastigotes cultures, (-)-gallocatechin (GC), (-)-epigallocatechin (EGC), (-)epigallocatechin gallate (EGCG), (-)-gallocatechin gallate (GCG) and whole extract polyphenol E (PE) showed anti-leishmanial activity against L. (L.) amazonensis and L. (V.) braziliensis with a range of IC50 between 31-51µg/ml and 32-151 µg/ml respectively. However, (+)-catechin and (-)-epicatechin did not show any activity on both Leishmania species with doses lower than 290 µg/ml. In addition, meglumine antimoniate (MA), one of the standard drugs for leishmaniasis treatment, was also tested against promastigotes, but no anti-leishmanial effect was observed with doses >1000 µg/ml. The PE and MA were also tested against intracellular amastigotes of L. (L.) amazonensis, and the IC50 was 10 ± 5 and 6 ± 3 µg/ml respectively. The SIRs for both PE and MA were greater than 1, suggesting that the compounds were more toxic to L. (L.) amazonensis than to J774.1 macrophages. In conclusion, in the present study the anti-leishmanial effects of GTC (GC, EGC, EGCG and GCG) and PE fraction were shown against L. (L.) amazonensis and L (V.) braziliensis promastigotes, and against intracellular amastigotes of L. (L.) amazonensis. Further studies in vitro will be performed in order to assess the sensitivity of other Leishmania species to GTC.