Probucol mitigates streptozotocin-induced cognitive and biochemical changes in mice.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by synaptic loss and cognitive impairments. Although AD is the most prevalent aging-related neurodegenerative disease, therapeutic strategies remain palliative. Recent studies have shown that probucol presents neuroprotective effects in experimental models of neurodegenerative disease. The present study aimed to investigate the potential protective effects of probucol against streptozotocin (STZ)-induced cognitive impairment and hippocampal biochemical changes (oxidative stress-related parameters, acetylcholinesterase (AChE) activity, cholesterol levels and ß-secretase (BACE) protein levels) in mice. Adult Swiss mice received STZ [150 µg/bilateral, i.c.v.], and treated daily with probucol (≅10 mg/kg/day, in drinking water, for 5 weeks,). Twenty-one days after i.c.v. administrations, STZ-infused animals displayed significant deficits in cognition (evaluated in the displaced and new object recognition tasks), which were paralleled by a significant increase in hippocampal AChE activity. Moreover, STZ-infused mice showed increased levels of BACE and decreased glutathione reductase (GR) activity in the hippocampus compared with the control group. Probucol treatment significantly protected against the behavioral and hippocampal biochemical changes induced by STZ. However, it was unable to prevent STZ-induced increase of hippocampal BACE levels and did not change hippocampal cholesterol levels. It is noteworthy that probucol treatment increased the glutathione peroxidase (GPx) activity per se independent of STZ injection. The present findings are the first to show that i.c.v. STZ infusions are able to increase hippocampal BACE expression. Moreover, the results also show that probucol can counteract STZ-induced cognitive impairments and biochemical parameters independently of potential modulator effects toward BACE levels. The study is the first to report the protective effects of probucol against STZ-induced biochemical hippocampal changes and behavioral impairments, rendering this compound a promising molecule for further pharmacological studies on the search for therapeutic strategies to treat or prevent AD.

Potentially adverse interactions between haloperidol and valerian.

This study was designed to determine whether the treatment with haloperidol (HP), valerian or both in association impairs the liver or kidney functions. Valerian alone did not affect oxidative stress parameters in the liver or kidney of rats. HP alone only increased glutathione (GSH) depletion in liver, but not in kidney. However, when HP was associated with valerian, an increase in lipid peroxidation levels and dichlorofluorescein (DCFH) reactive species production was observed in the hepatic tissue. Superoxide dismutase (SOD) and Catalase (CAT) activities were not affected by the HP plus valerian treatment in the liver and kidney of rats. HP and valerian when administered independently did not affect the activity of hepatic and renal delta-aminolevulinate dehydratase (delta-ALA-D), however, these drugs administered concomitantly provoked an inhibition of hepatic delta-ALA-D activity. The delta-ALA-D reactivation index was higher in rats treated with HP plus valerian than other treated groups. These results strengthen the view that delta-ALA-D can be considered a marker for oxidative stress. Serum aspartate aminotransferase (AST) activity was not altered by any treatment. However, serum alanine aminotransferase (ALT) activity was higher in the HP group and HP plus valerian group. Our findings suggest adverse interactions between haloperidol and valerian.