Efeitos do chá verde (Camellia sinensis) e da epigalocatequina-3-galato sobre a hemostasia e o desenvolvimento tumoral do melanoma em células B16-F10

Abstract

Cancer is a multifactorial disease that comes up from disorderly growth of atypical cells resulting in tissue invasions that lead to tumor formation. Among the of the most diverse types of existing cancers, melanoma-type skin cancer is one of the most dangerous, especially in countries with a tropical climate, duo to the high incidence of sunlight. Based on this, several treatments are studied around the world, with the aim of improving the effectiveness and quality of life of patients who suffer from the side effects of conventional cancer treatments. Seeking to reduce the adverse effects resulting from usual antineoplastic molecules, several studies have investigated the effect of plants on tumor progession and on the hypercoagulable state that is associated with cancer. Among the most studied medicinal plants currently is Camellia sinensis, from which green tea is extracted and EGCG (Major compound of green tea). Based on the above, the aim of this study was to evaluate the effect of the green tea and EGCG on hemostasis and melanoma tumor development, which may be contributing as an adjuvant in traditional cancer treatment. The present study evaluated the antitumor, antiangiogenic and anticoagulant properties of green teat and EGCG. During the various experiments carried out, the tested concentrations of green tea and EGCG were 25μg/mL, 50μg/mL e 100μg/mL. It was observed in the platelet aggregation test a potent effect of green tea decreasing by up to 50% and EGCG decreasing by about 85% when compared to the negative control. The evaluation of the effects of green tea and EGCG on cell death through the apoptosis test by incubation with DAPI revealed a reduction of around 25% and 50% of green tea and EGCG, respectively. During the angiogenesis experiment performed with endothelial cells, there was a reduction in the formation of new blood vessels of about 25% in the presence of green tea and about 99% in the presence of EGCG at concentrations of 100μg/mL; In the study of the possible effect of green tea and MCGT on the reduction of VEGF and IL-8 secretion, VEGF and IL-8 production were inhibited in the presence of green tea by 55% and 20% respectively; and in the presence of EGCG there was a 75% reduction in VEGF inhibition and about 80% in the inhibition of IL-8 secretion; in both cases at a concentration of 100μg/mL. Therefore, the effects of green tea and EGCG on primary hemostasis and tumor development are evidenced through the results, and further studies are needed to clarify the action of these substances.