Atividades melanogênica, genotóxica e antiproliferativa de extratos de Brosimum gaudichaudii Trécul e Dorstenia brasiliensis Lam induzidas por radiação UVA.

Abstract

The linear furanocoumarins or psoralens are photosensitizers used in dermatology associated with ultraviolet A in the treatment of diseases such as vitiligo. Photochemotherapy has immediate adverse reactions (nausea, pruritus, erythema and xeroderma) and late (carcinogenesis and possibly cataracts). In Brazil, there are no medication or herbal products containing plant extracts for treatment of vitiligo that comply with current legislation of the National Agency for Sanitary Vigilance. The objective of this study was to analyze extracts of species of the Cerrado containing furanocoumarins and evaluate their melanogenic, mutagenic and antiproliferative activities. The quantification of furanocoumarins by high performance liquid chromatography coupled with photodiode array detector (HPLC-DAD) revealed 40.77 mg / g of 5-methoxypsoralen (5-MOP) in Brosimum gaudichaudii extract and 85.33 mg / g of psoralen + 5-MOP in Dorstenia brasiliensis extract. Chromatographic profiles were obtained for quality control of extracts on thin layer chromatography (TLC) and HPLC-DAD. The dorstenin was identified in the D. brasiliensis extract by gas chromatography coupled to mass spectrometry (GC-MS). The extracts of B. gaudichaudii and D. brasiliensis and the furanocoumarins psoralen, 5-MOP and 8-methoxypsoralen (8-MOP) showed strong antiproliferative activity (GI50 of 2.45, 2.05, 0.25, 2.30, and 0.28 μg / mL, respectively) in the in vitro assay with B16-F10 cells by SRB method in the presence of UVA. All samples were inactive in the absence of irradiation. Two tests were standardized for evaluate melanogenic activity: activation of tyrosinase and melanin dosage. Both extracts showed activity. The extracts of B. gaudichaudii and D. brasiliensis showed genotoxic activity in the in vivo Somatic Mutation And Recombination Test (SMART) of the wings of Drosophila melanogaster in the presence of UVA. The extract of D. brasiliensis showed higher genotoxicity that the extract of B. gaudichaudii the SMART with descendants of the pattern strain (ST) of D. melanogaster. The evaluation of the test in the high bioactivation strain (HB) revealed the presence of progenotoxic substances as components of the extract of B. gaudichaudii. In the absence of UVA, the D. brasiliensis extract showed small, but significant genotoxic activity.