Mode of action of the sesquiterpene lactones eupatoriopicrin and estafietin on Trypanosoma cruzi.

BACKGROUND: The sesquiterpene lactones (STLs) eupatoriopicrin (EP) and estafietin (ES), isolated from Stevia alpina Griseb. (Asteraceae) and Stevia maimarensis (Hieron.) Cabrera (Asteraceae) respectively, have previously showed promising trypanocidal activity, both in vitro and in vivo. PURPOSE: In this work, using biochemical studies and electron microscopy, we aimed at characterizing the mode of action of both STLs on Trypanosoma cruzi. METHODS: The interaction of STLs with hemin was examined by measuring modifications in the Soret absorption band of hemin; the thiol groups interaction was determined spectrophotometrically through its reaction with 5,5'-dithiobis-2-nitrobenzoate; the effect on cruzipain activity was also assayed by spectrophotometry. The synthesis of sterols were qualitatively and quantitatively tested by TLC. Mitochondrial functionality was assessed by measuring mitochondrial membrane potential and the activity of NADH-cytochrome c reductase and succinate-cytochrome c reductase enzymes. The status of the antioxidant system was assessed by quantifying the level of free thiols by spectrophotometry, together with the intracellular oxidative state by flow cytometry. Ultrastructural changes were analyzed by transmission electron microscopy. RESULTS: EP and ES were found to impair the functionality and the redox status of the parasite. ES produced a greater decrease in the activity of succinate dehydrogenase than eupatoriopicrin, affecting the functioning of the respiratory chain and the Krebs cycle. EP increased the formation of triglycerides leading to the presence of cytoplasmic lipid droplets. By electron microscopy, alterations in the kinetoplast and the appearance of large translucent vacuoles in the cytoplasm were observed for both compounds. CONCLUSIONS: Both sesquiterpenelactones proved to act additively on T. cruzi, supporting the hypothesis that each compound would be acting on different primary targets.. The treatment combining eupatoriopicrin and estafietin could be considered a promising alternative for the treatment of Chagas' disease.

Time to develop chronic kidney disease in an Ecuadorian Type 2 Diabetes Mellitus cohort: Survival analysis in primary care.

Chronic Kidney Disease (CKD) represents a high burden to health systems. However, the survival time for CKD in a Type 2 Diabetes Mellitus (T2DM) population is unknown. AIMS: Determine the risk factors, survival time and the incidence rate of CKD in T2DM. METHODS: Retrospective clinical cohort study (follow up 10 years). 513 patients with T2DM were included. Numerical variables were compared using the mean difference. Chi squared and odds ratios were calculated for categorical variables. Survival analysis was done through life tables and Kaplan-Meier. RESULTS: The mean difference between the group that developed CKD and those who did not, was significant in: age, age at diagnosis of T2DM and years with T2DM. Risk factors for developing CKD were: the presence of hypertension, albuminuria, retinopathy, high triglycerides and high HbA1c. The incidence rate was 32.07 per 1000 person-years of follow-up and 207 (40.4%) of patients developed CKD during the study. The median for developing CKD was 20.52 years of disease with an increasing risk with time. CONCLUSIONS: Half of the patients with T2DM will develop CKD by the second decade of disease. Time, arterial hypertension, retinopathy, albuminuria and triglycerides are factors associated with CKD in patients with T2DM.