IN VITRO TRYPANOCIDAL AND ANTIFUNGAL ACTIVITIES OF MAYTENUS VISCIFOLIA GRISEB (CELASTRACEAE)

PIÑEIRO, MAURICIO; LIMA, BEATRIZ; BARRERA, PATRICIA; SORTINO, M; MARQUEZ, JUSTO; SOSA, MIGUEL; TAPIA, ALEJANDRO

San Luis

Congreso; XXXVII Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2019

Maytenus viscifolia, popularly known as ?sombra de toro?, in San Juan it is frequent in the Departments of Valle Fértil, and Caucete. So far the antioxidant activity and mineral content and fatty acids of the fruits of this species have been reported. The aim was evaluate the in vitro trypanocidal and antifungal activities of apolar extracts from M. viscifolia collected in province of San Juan (Argentina). Five hundred grams of dried and ground root were extracted with soxhlet with a mixture of petroleum ether: ethyl ether (1:1, three times, 1 h). The extracts were filtered and concentrated to afford petroleum ether: ethyl ether extract (PE-EEE). The antifungal activity (MIC/MFC) was carried out following the Clinical and Laboratory Standards Institute (CLSI) guidelines for yeast and filamentous fungi. To the assessment of trypanocidal activity, 3x106 epimastigotes/mL were incubated in Diamond?s medium supplemented with 15% fetal bovine serum and hemin at 28 °C. Treatments were performed with a concentration of 50 μg/mL of PE-EEE (dissolved in DMSO). Negative control: parasites incubated without extract; positive control: parasites incubated with benznidazole (5 μg/mL). Aliquots of the cultures were collected at 24, 48 and 72 h, and were counted in Neubauer chamber under optical microscopy to evaluate growth. To evaluate the survival, aliquots (24 and 48 h) were stained (eosin exclusion test) and observed under optical microscopy. The growth of T. cruzi treated with PE-EEE was significantly lower than the negative control. The survival is close to 0 % at 48 h for PE-EEE, whereas the controls negative and positive present a survival close to 100 %. The PE-EEE showed a strong trypanocidal effect and moderated antifungal activity (MICs ≤ 1000µg/mL). The bioassay-guided fractionation by Sephadex LH 20 and silica gel column of PE-EEE led to the isolation of quinonemethide triterpene pristimerina. Their structure was characterized by1H-NMR, 13C-NMR, and ES-MS experiments. Pristimerin showed a potent trypanocidal activity and moderated antifungal activity against Cryptococcus neoformans ATCC 32264; Microsporum gypseum C 115 2000, Trichophyton rubrum C 113 2000 and Trichophyton mentagrophytes ATCC 997 (MICs/MFCs between 500-1000 µg/ml). Authors are grateful to CICITCA-UNSJ, UNCuyo.