Candimine from Hippeastrum escoipense (Amaryllidaceae): Anti-Trypanosoma cruzi activity and synergistic effect with benznidazole.

• Hippeastrum escoipense is a potential source for the treatment of Chagas disease. • Candimine decreases the cytotoxic effect of benznidazole in mammalian cells. • Candimine induces alterations in the ultrastructure of T. cruzi. • The combination between candimine and benznidazole shows a synergistic effect in anti- T. cruzi assays. Chagas disease (CD), caused by Trypanosoma cruzi , represents a health threat to around 20 million people worldwide. Side effects of benznidazole (Bzn) cause 15–20% of patients to discontinue their treatment. Evidence has increased in favor of the use of drug combinations to improve the efficacy and tolerance of the treatment. Natural products are well known to provide structures that could serve as new drugs or scaffolds for CD treatment. Spp of the Amaryllidoideae sub family of Amaryllidaceae family are known by their bioactives alkaloids, which have been reported by their antiparasitic activities. To evaluate the anti- T. cruzi activity of the isolated alkaloid candimine (Cnd) from Hippeastrum escoipense Slanis & Huaylla; and to assess the combination effect between Cnd and Bzn against different life stages of T. cruzi parasites. The chemical profile of H. escoipense alkaloids extract (AE- H. escoipense), including quantitation of Cnd was performed through GC/MS and UPLC-MS/MS techniques. Subsequently, Cnd was isolated using Shephadex LH-20. Then, the AE- H. escoipense and Cnd were tested against T. cruzi , (epimastigotes, trypomastigotes, and amastigotes) by in vitro proliferation and viability assays. The cytotoxicity was evaluated against Vero and HepG2 mammalian cells. The ultrastructural analysis was perform by transmission electron microscopy (TEM) and mitochondrial activity was carried out by MTT assay. Drug combination assay between Cnd and Bzn was evaluated using the Chou-Talalay method. The AE- H. escoipense and Cnd showed high and specific anti- T. cruzi activity, comparable to Bzn. Cnd induces ultrastructural changes in T. cruzi , such as vacuolization, membrane blebs, and increased mitochondrial activity. Regarding the interaction between Cnd and Bzn, it generates synergism in the combinations of 0.25×IC 50 in epimastigotes, 2×IC 50 in trypomastigotes+amastigotes, and 0.25, 2, and 4×IC 50 in amastigotes. The synergism between Cnd and Bzn indicates that the combination at the concentration of 4×IC 50 could be useful as an effective new therapy against CD in the chronic stage. Thus, Cnd isolated from the leaves of H. escoipense emerges as potential candidate for the development of a new drug for the treatment of CD. [Display omitted] [ABSTRACT FROM AUTHOR]