Protective Effects of Gallic Acid against Streptozotocin-induced Oxidative Damage in Rat Striatum.

The present study aimed to investigate the protective effects of gallic acid (GA) against ICV STZ-induced oxidative damage in the rat striatum. Animals were randomly divided into 4 groups (8 each). Group 1 (Sham), were injected ICV on day 1 and 3 with artificial CSF and treated with normal saline (2 ml/kg, p.o.). Group 2 (sham+GA), were injected ICV on day 1 and 3 with artificial CSF and treated with GA (30 mg/kg, p.o.) for 26 days. Group 3 (lesion) were injected with ICV-STZ (3 mg/kg bilaterally, on day 1 and 3) and received normal saline (2 ml/kg, p.o.) as vehicle. Group 4 (lesion+GA), were injected with ICV-STZ (3 mg/kg bilaterally, on day 1 and 3) and treated with gallic acid (30 mg/kg, p.o.) once daily for 26 days starting 5 days before the first injection of ICV STZ. The homogenized striatum was used for measuring thiobarbituric acid reactive species (TBARS) and total thiol contents, glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD) activities. The results showed that ICV STZ-injection increased the level of TBARS (+69.3%) and decreased total thiol concentration (-48.8%), GPx (-47.3%), CAT (-47.1%) and SOD (-30.7%) activities. In contrast, chronic administration of GA significantly prevented the biochemical alterations in the ICV-STZ rats. These findings highlight the beneficial role of GA via enhancement of cerebral antioxidant defense system.

Protective effects of oral crocin against intracerebroventricular streptozotocin-induced spatial memory deficit and oxidative stress in rats.

Intracerebroventricular (ICV) streptozotocin (STZ) has been shown to cause cognitive impairment, associated with free radical generation. In this study, we evaluated the effects of crocin on cognitive performance in ICV STZ-lesioned rats (3 mg/kg bilaterally, on day 1 and 3). Crocin (100 mg/kg, p.o.) was administered for 21 consecutive days, starting 1h prior to the first dose of STZ. Cognitive performance was assessed using Morris water maze task while the parameters of oxidative stress assessed, were malondialdehyde (MDA) and total thiol levels besides glutathione peroxidase (GPx) activity. STZ-lesioned rats showed a severe deficit in memory associated with elevated MDA levels, reduced GPx activity and total thiol content. Crocin treatment improved cognitive performance and resulted in a significant reduction in MDA levels and elevation in total thiol content and GPx activity. This study demonstrates that crocin may have beneficial effects in the treatment of neurodegenerative disorders such as Alzheimer's disease.

Gender-dependent behavioural impairment and brain metabolites in young adult rats after short term exposure to lead acetate.

We investigated the behavioural effects of short-term lead (Pb) exposure in adult rats producing blood Pb concentration (<10 µg/dL) below those associated with neurological impairment in occupationally exposed individuals. In order to assess gender differences, we performed parallel behavioural experiments in male and female rats. Exposure to Pb acetate (50 mg/L in drinking water) for 30-45 days induced behavioural alterations consisting in hyperactivity in a novel environment and impairment of spatial memory. These effects were observed only in male rats. Object recognition, motor coordination were unaffected by Pb exposure. Magnetic resonance spectroscopy allows in vivo assessment of main brain metabolites (glutamate/glutamine, creatine, myoinositol, N-acetylaspartate and choline) whose changes have been demonstrated in several central nervous system pathologies. Exposure to Pb did not affect metabolite profile in the striatum and increase myoinositol signal in the hippocampus of male rats. The increase in myoinositol in hippocampus suggests early Pb-induced alteration in glial metabolism in this brain region and may represent a potential marker of early brain dysfunction during Pb exposure.