Antioxidant effects on the intracerebroventricular galactose damage in rats

Classical Hereditary galactosemia: findings in patients and animal models

Classic galactosemia is a rare inborn error of metabolism that affects the metabolism of galactose, a sugar derived from milk and derivates. Classic galactosemia is caused by variants of the GALT gene, which lead to absent or misfolded forms of the ubiquitously present galactose-1-phosphate uridylyltransferase enzyme (GALT) driving galactose metabolites to accumulate, damaging cells from neurons to hepatocytes. The disease has different prevalence around the world due to different allele frequencies among populations and its symptoms range from cognitive and psychomotor impairment to hepatic, ophthalmological, and bone structural damage. The practice of newborn screening still varies among countries, dairy restriction treatment is a consensus despite advances in preclinical treatment strategies. Recent clinical studies in Duarte variant suggest dairy restriction could be reconsidered in these cases. Despite noteworthy advances in the classic galactosemia understanding, preclinical trials are still crucial to fully understand the pathophysiology of the disease and help propose new treatments. This review aims to report a comprehensive analysis of past studies and state of art research on galactosemia screening, its clinical and preclinical trials, and treatments with the goal of shedding light on this complex and multisystemic innate error of the metabolism.

Effects of resveratrol on alterations in cerebrum energy metabolism caused by metabolites accumulated in type I citrullinemia in rats

We investigated the in vitro effects of citrulline (0.1, 2.5 and 5.0 mM) and ammonia (0.01, 0.1 and 1.0 mM), and the influence of resveratrol (0.01 mM, 0.1 mM and 0.5 mM) on pyruvate kinase, citrate synthase, succinate dehydrogenase (SDH), complex II, and cytochrome c oxidase activities in cerebral cortex, cerebellum and hippocampus homogenates of 60-day-old male Wistar rats. Results showed that 2.5 and 5.0 mM citrulline decreased pyruvate kinase activity in cerebral cortex and, at a concentration of 5.0 mM, increased its activity in hippocampus. Additionally, 5.0 mM citrulline increased citrate synthase activity in the cerebellum of rats. Citrulline (5.0 mM) reduced complex II and cytochrome c oxidase activities in cerebral cortex and hippocampus. With regard to ammonia, at 0.1 and 1.0 mM, decreased complex II activity in cerebral cortex and at 1.0 mM decreased its activity in cerebellum and hippocampus. Ammonia (1.0 mM) also decreased cytochrome c oxidase activity in cerebral cortex and cerebellum of rats. Resveratrol was able to prevent most of the alterations caused by these metabolites in the biomarkers of energy metabolism measured in the cerebrum of rats. Data suggest that these alterations in energy metabolism, caused by citrulline and ammonia, are probably mediated by the generation of free radicals, which can in turn be scavenged by resveratrol.