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.

Abstract: Type 1 diabetes (T1D) is the result of the selective destruction of the pancreatic β-cells by T cells of the immune system. Although spleen is a secondary lymphoid organ, it is also involved in the T1D pathogenesis. However, the alterations in a variety of cellular processes of this disease need to be further understood. We aimed to analyze the benefits of resveratrol, and its complexed form on diabetic complications in the spleen of rats. To this end, we investigated important enzymes of phosphoryl transfer network, and Na+, K+-ATPase activity. Wistar rats were divided into non-diabetic groups: Control, Ethanol, Resveratrol, Hydroxypropyl-β-cyclodextrin, Resveratrol-hydroxypropyl-β-cyclodextrin, and diabetic groups with the same treatments. Diabetes was induced by a single dose of 60 mg/kg of streptozocin intraperitoneally, and treatments by intragastric gavage once daily for 60 days. Hyperglycemia reduced creatine kinase activity, which was reversed by the administration of resveratrol. Na+, K+-ATPase activity was greatly affected, but it was reversed by resveratrol and resveratrol-hydroxypropyl-β-cyclodextrin. This suggest an energetic imbalance in the spleen of diabetic rats, and in case this also occurs in the diabetic patients, it is possible that resveratrol supplementation could be beneficial to the better functioning of the spleen in diabetic patients.

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.

RESUMO Considerando que a doença de Alzheimer é uma doença neurodegenerativa prevalente em todo o mundo, buscou-se investigar o envolvimento da atividade de três quinases: creatinaquinase, piruvatoquinase e adenilatoquinase no hipocampo e no córtex cerebral em um modelo da doença de Alzheimer. Os camundongos Swiss, machos, adultos, receberam β-amiloide ou solução salina. Um dia depois, os camundongos foram tratados com nanocápsulas vazias (17 ml/kg) ou nanocápsulas contendo meloxicam (5 mg/kg) ou meloxicam livre (5 mg/kg). Os tratamentos foram realizados em dias alternados, até o final do ptotocolo experimental. No décimo quarto dia, as atividades das quinases foram avaliadas. A β-amiloide não alterou a atividade das quinases no hipocampo e no córtex cerebral dos camundongos. No entanto, o meloxicam livre diminuiu a atividade da creatinaquinase na fração mitocondrial no grupo induzido pela β-amiloide, mas na fração citosólica observou-se um aumento na atividade da piruvatoquinase no córtex cerebral. Além disso, o tratamento com as nanocápsulas contendo meloxicam diminuiu a atividade da adenilatoquinase no hipocampo dos camundongos induzidos pela β-amiloide. Em conclusão, observamos ausência de efeitos de curto prazo nas atividades das quinases do metabolismo energético no hipocampo e no córtex cerebral de camundongos, no modelo induzido com o peptídeo amiloide-β. Esses resultados estabeleceram uma base para um estudo mais aprofundado das quinases em alterações na rede de fosforiltransferência observadas nos cérebros de pacientes pós-morte com a doença de Alzheimer.

ABSTRACT Considering that Alzheimer's disease is a prevalent neurodegenerative disease worldwide, we investigated the activities of three key kinases: creatine kinase, pyruvate kinase and adenylate kinase in the hippocampus and cerebral cortex in Alzheimer's disease model. Male adult Swiss mice received amyloid-β or saline. One day after, mice were treated with blank nanocapsules (17 ml/kg) or meloxicam-loaded nanocapsules (5 mg/kg) or free meloxicam (5 mg/kg). Treatments were performed on alternating days, until the end of the experimental protocol. In the fourteenth day, kinases activities were performed. Amyloid-β did not change the kinases activity in the hippocampus and cerebral cortex of mice. However, free meloxicam decrease the creatine kinase activity in mitochondrial-rich fraction in the group induced by amyloid-β, but for the cytosolic fraction, it has raised in the activity of pyruvate kinase activity in cerebral cortex. Further, meloxicam-loaded nanocapsules administration reduced adenylate kinase activity in the hippocampus of mice injected by amyloid-β. In conclusion we observed absence in short-term effects in kinases activities of energy metabolism in mice hippocampus and cerebral cortex using amyloid-β peptide model. These findings established the foundation to further study the kinases in phosphoryltransfer network changes observed in the brains of patients post-mortem with Alzheimer's disease.