β-Cyclodextrins alter the energy metabolism-related enzyme activities in rats

Abstract Although widely used in medicine, separation technology, and other fields, the effects of cyclodextrins on the activities of phosphoryl transfer enzymes have not been previously evaluated. In vivo studies evaluated the function of cyclodextrins as active compounds. Despite the use of cyclodextrins as active compounds, the effects of cyclodextrins on hepatic and renal tissues remain to be fully elucidated. The primary objective of this study was to evaluate the effects of β- cyclodextrins, methyl-β-cyclodextrin (M-β- cyclodextrins), and (2-hydroxypropyl)-β-cyclodextrin (HP-β-cyclodextrins) on enzyme activities regulating the maintenance of energy homeostasis in the kidney and liver tissues in relation to toxicity. Serum levels of liver and kidney markers were measured, and oxidative stress parameters were assessed. After 60-day treatments, we observed that the administration of β-cyclodextrins and M-β-cyclodextrins inhibited the hepatic activity of pyruvate kinase, an irreversible enzyme within the glycolytic pathway. Additionally, administration of HP-β-cyclodextrins inhibited creatine kinase activity and increased the total sulfhydryl content in kidneys. Here, we demonstrated for the first time that β-cyclodextrins, M-β-cyclodextrins, and HP-β-cyclodextrins cause bioenergetic dysfunction in renal and hepatic tissues. These findings suggest that understanding the balance between cyclodextrins’ efficacy and adverse effects is essential for better accepting their use in medicine

Administração aguda de leucina provoca uma diminuição nos níveis plasmáticos de vários aminoácidos alifáticos

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Administração aguda de leucina provoca uma diminuição nos níveis plasmáticos de vários aminoácidos alifáticos

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Thiol/disulfide status regulates the activity of thiol-containing kinases related to energy homeostasis in rat kidney

<div><p>ABSTRACT Considering that thiol-containing enzymes like kinases are critical for several metabolic pathways and energy homeostasis, we investigated the effects of cystine dimethyl ester and/or cysteamine administration on kinases crucial for energy metabolism in the kidney of Wistar rats. Animals were injected twice a day with 1.6 µmol/g body weight cystine dimethyl ester and/or 0.26 µmol/g body weight cysteamine from the 16th to the 20th postpartum day and euthanized after 12 hours. Pyruvate kinase, adenylate kinase, creatine kinase activities and thiol/disulfide ratio were determined. Cystine dimethyl ester administration reduced thiol/disulfide ratio and inhibited the kinases activities. Cysteamine administration increased the thiol/disulfide ratio and co-administration with cystine dimethyl ester prevented the inhibition of the enzymes. Regression between the thiol/disulfide ratio, and the kinases activities were significant. These results suggest that redox status may regulate energy metabolism in the rat kidney. If thiol-containing enzymes inhibition and oxidative stress occur in patients with cystinosis, it is possible that lysosomal cystine depletion may not be the only beneficial effect of cysteamine administration, but also its antioxidant and thiol-protector effect.</p></div