In vitro tripanocidal effect of 1,8-dioxooctahydroxanthenes (xanthenodiones) and tetraketones and improvement of cardiac parameters in vivo.

OBJECTIVE: Trypanosoma cruzi infection affects millions of people worldwide, and the drugs available for its treatment have limited efficacy. 1,8-Dioxooctahydroxanthenes and tetraketones are compounds with important biological applications. The aim of this study was to assess the trypanocidal and inflammatory activities of nine 1,8-dioxooctahydroxanthenes (1-9) and three tetraketones (10-12). METHODS AND RESULTS: By in vitro killing assay, three compounds were able to eliminate CL TdTomato expressing strain of T. cruzi, 9 (IC50=30.65µM), 10 (IC50=14.11µM), and 11 (IC50=26.43µM). However, only 9 was not toxic to Vero cells. Next, to evaluate the in vivo antitrypanosomal and immunological efficacy of 9, Swiss mice were infected with the Y and CL strains of T. cruzi and treated for 10 days with 50mg/kg of 9. This compound reduced the cardiac inflammatory infiltration in animals infected with both strains. Rank's ligand (RankL), CCL2, and interferon (IFN)-γ were measured in the cardiac tissue homogenate of the Y-strain-infected animals, and no interference of 9 was observed. However, compound 9 increased the RankL and interleukin (IL)-10 levels in CL-infected mice. No hepatic and renal toxicity was observed. CONCLUSION: Our findings showed that 1,8-dioxooctahydroxanthene has antiparasitic effect and ameliorates the cardiac inflammatory parameters related to T. cruzi infection.

Potential Antivirals: Natural Products Targeting Replication Enzymes of Dengue and Chikungunya Viruses.

Dengue virus (DENV) and chikungunya virus (CHIKV) are reemergent arboviruses that are transmitted by mosquitoes of the Aedes genus. During the last several decades, these viruses have been responsible for millions of cases of infection and thousands of deaths worldwide. Therefore, several investigations were conducted over the past few years to find antiviral compounds for the treatment of DENV and CHIKV infections. One attractive strategy is the screening of compounds that target enzymes involved in the replication of both DENV and CHIKV. In this review, we describe advances in the evaluation of natural products targeting the enzymes involved in the replication of these viruses.