ABSTRACT
Entamoeba histolytica is the causative agent of human amoebiasis, which mainly affects developing countries. Although several drugs are effective against E. histolytica trophozoites, the control of amoebiasis requires the development of new and better alternative therapies. Medicinal plants have been the source of new molecules with remarkable antiprotozoal activity. Incomptine A isolated from Decachaeta incompta leaves, is a sesquiterpene lactone of the heliangolide type which has the major in vitro activity against E. histolytica trophozoites. However the molecular mechanisms involved in its antiprotozoal activity are still unknown. Using a proteomic approach based on two-dimensional gel electrophoresis and mass spectrometry (ESI-MS/MS) analysis, we evidenced that 21 E. histolytica proteins were differentially expressed in response to incomptine A treatment. Notably, three glycolytic enzymes, namely enolase, pyruvate:ferredoxin oxidoreductase and fructose-1,6-biphosphate aldolase, were down-regulated. Moreover, ultrastructural analysis of trophozoites through electronic microscopy showed an increased number of glycogen granules. Taken together, our data suggested that incomptine A could affect E. histolytica growth through alteration of its energy metabolism.
Subject(s)
Asteraceae/chemistry , Energy Metabolism/drug effects , Entamoeba histolytica/drug effects , Lactones/pharmacology , Sesquiterpenes/pharmacology , Blotting, Western , Down-Regulation , Dysentery, Amebic/drug therapy , Electrophoresis, Gel, Two-Dimensional , Entamoeba histolytica/metabolism , Entamoeba histolytica/ultrastructure , Gene Expression/drug effects , Gene Expression Regulation, Enzymologic/drug effects , Glycogen/metabolism , Humans , Inhibitory Concentration 50 , Lactones/isolation & purification , Microscopy, Electron, Transmission , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Plant Leaves/chemistry , Plants, Medicinal/chemistry , Protozoan Proteins/genetics , Protozoan Proteins/metabolism , Sesquiterpenes/isolation & purification , Spectrometry, Mass, Electrospray Ionization , Tandem Mass SpectrometryABSTRACT
We report the effect of the Sesquiterpene Lactones Ambrosin, Incomptine B and Glaucolide E against seven strains of Trypanosoma cruzi, the etiological agent of Chagas Disease. These compounds were isolated from Parthenium hysterophorus, Decachaeta incompta, and Vernonia liatroides, respectively. We evaluated by flow cytometry the viability of epimastigotes. Ambrosin was the most effective, then Incomptine B, and Glaucolide E (IC50â¯=â¯67.1, 123.7, and 215.1⯵M, respectively). These compounds were more potent than the drugs Benznidazole (IC50â¯>â¯400⯵M) and Nifurtimox (IC50â¯=â¯199.7 to >400⯵M). Toxicity to mammalian Vero and Jurkat cells was also determined in vitro. All the compounds had a poor selective index (0.003-1.859). Toxicoinformatics is useful to forecast in silico toxicological and pharmacokinetic properties. Ambrosin and Incomptine B may not possess mutagenic, tumorigenic, or reproductive effects. Glaucolide E could possess a low mutagenic and high tumorigenic effects, and probably target the Amine Oxidase A, Prostaglandin and G/H Synthase I. Interestingly, Ambrosin, Incomptine B and Glaucolide E, comply with Lipinsky Rule of Five, indicating a suitable pharmacokinetic profile. Ambrosin and Incomptine B possess high trypanocidal activity, and pharmaceutical properties suitable for development; however, their safety profile should be optimized by structural modifications.