Antileishmanial and cytotoxic activities of three plants used in colombian folk medicine

As part of our research on medicinal plants traditionally used in folk medicine in Casanare (Colombia), some important species were selected for further studies through phytochemical exploration. In this study, we investigate the phytochemical profile, antileishmanial and cytotoxic activities of three selected plants (Bowdichia virgilioides, Jacaranda obtusifolia, and Hymenaea courbaril). These plants are commonly used in the above-mentioned region to treat different infectious diseases. Leaves from test plants were collected in Casanare, Colombia, dried, grounded and macerated with ethanol. The chemical profile was determined by UFLC-DAD analysis and by measuring total phenolic (TP) and total flavonoid (TF) contents. They were also tested against promastigotes of Leishmania panamensis, J774 murine macrophages and THP-1 monocytes in order to examine a preliminary extracts' ability and security in a screening platform. The TP and TF contents (> 30 mg gallic acid equiv/g DE and > 3 mg quercetin equiv/g DE, respectively) were found to be reasonable. Chemical characterization of the ethanol extracts was achieved by UFLC-DAD employing a validated method for profiling herbal extracts using standards. All extracts were found to be enriched in flavonoid-related metabolites. Antileishmanial activity of extracts exhibited relatively high EC₅₀ values (20 – 100 µg/mL). The extract from Hymenaea courbaril was the most active (EC₅₀= 20.1 µg/mL). Additionally, a low cytotoxiciy against J774 and THP-1 was determined for all extracts (IC₅₀ > 600 µg/mL, selectivity indexes (SI) > 8). Although the activity against promastigotes is quite low, and tests with the more relevant amastigotes must follow, these results might be related to the traditional use of these plants to treat infections. Therefore, the evaluation of test extracts against amastigotes and a bioguided fractionation to obtain bioactive compounds is currently in progress.