Alpha lipoic acid ameliorates THIM-induced prefrontal cell loss and abnormal enzymatically contents in the developing rat.

Thimerosal (THIM) is a common preservative used in many pharmaceutical drugs, vaccines, cosmetics and many other products. Today, it was somewhat clear that Thimerosal (THIM) is a neurotoxicant preservative. We aimed to use of a suitable agent for preventing of THIM side effects on brain. Therefore, in this research, the protective effects of Alpha Lipoic Acid (ALA), against THIM-induced brain cell loss, changes in neuroimmune cell and enzymatically contents were examined. Male Wistar rats (n = 60) were randomly distributed into five groups: 1- THIM group; this group received THIM at dose of 300 µg /kg on 7, 9, 11, 15 days after birth 2- ALA group; received ALA (20 mg/kg) in the same order. 3- THIM & ALA group; this group received ALA in the same dose, 30 min before THIM administration.4& 5; Saline and ALA vehicle groups were also included. At 56th postnatal day, samples of the prefrontal cortex were collected and prepared for stereological, immune-histochemical, and enzymatic evaluations. The result showed that ALA, prevents the adverse effects of THIM on brain cell loss, abnormal changes in neuroimmune cells (p < 0.05), prefrontal cortex volume (p < 0.05), and the glutathione content of prefrontal cortex (p < 0.05). In conclusion, neonatal exposure to THIM can induce abnormal alterations in neuroimmune cells and brain cell density as well as prefrontal cortex volume & glutathione content, and ALA can ameliorate these abnormalities.

Long-term administration of high-dose methylphenidate-induced cerebellar morphology and function damage in adult rats.

BACKGROUND AND AIM: Stated in previous studies, physicians are typically prescribing methylphenidate (MPH), commonly known as Ritalin, for children diagnosed with attention deficit hyperactivity disorder (ADHD). Nevertheless, researchers have not still understood mechanisms of this stimulant medication. Research has also found an association between apoptosis signaling pathway, neurological disorder, as well as treatment targets for neurological diseases. Therefore, the present study investigated effects of 3-week Ritalin oral (20 mg/kg) administration versus vehicle therapy on cerebellar morphology and function in adult male rats. MATERIALS AND METHODS: A total number of 30 adult male rats were randomly but equally divided into control and treatment groups. In fact, the treatment group was administered by Ritalin at doses of 20 mg/kg for 21 days and the control group only received saline. At the end of weeks 1, 2, and 3 following drug treatment, rotarod performance test was fulfilled. Once the study ended, tissues of the cerebellum were separated; then, inflammation parameters (i.e. tumor necrosis factor [TNF- α] and interleukin 1 beta [IL-1ß]), pro-apoptotic genes (that is, bcl-2-associated X [bax] and caspase-8 proteins), along with histological changes were analyzed. RESULTS: According to the findings, Ritalin with the high dose of 20 mg/kg could remarkably enhance the levels of bax and caspase-8 genes compared with those in the control group (p < 0.05). It should be noted that treatment with Ritalin could significantly increase TNF-α and IL-1ß levels in isolated cerebellar cells (p < 0.05). Moreover, 20 mg/kg of Ritalin decreased mean volumes of granular layer, white matter, as well as molecular layers. It also reduced the number of Purkinje cells compared with those in control rats. In addition, lower coordination movement was observed in the group receiving Ritalin. CONCLUSION: Data analysis showed that chronic treatment with increased dose of Ritalin could possibly lead to neuroinflammation and neurodegeneration in the cerebellum of adult rats.

Alterations of neuroimmune cell density and pro-inflammatory cytokines in response to thimerosal in prefrontal lobe of male rats.

Evidence suggests that the effect of heavy metals on neuroimmune cells lead to neurogenic inflammatory responses. In this study, immune cells [mast cells (MCs) and microglia] and pro-neuroinflammation cytokines (interleukin-1b and tumor necrosis factor-α) were assessed in the prefrontal lobe of rat brains exposed to thimerosal in different timeframes. A total of 108 neonatal Wistar rats were divided into three groups having three subgroups. The experimental groups received a single dose of thimerosal (300 µg/kg) postnatally at 7, 9, 11, and 15 days. The vehicle groups received similar injections of phosphate-buffered saline in a similar manner. The control groups received nothing. Samples of the prefrontal cortex were collected and prepared for stereological, immunohistochemical, and molecular studies at timeframes of 12 or 48 h (acute phase) and 8 days (subchronic phase) after the last injection. The average density of the microglia and MCs increased significantly in the experimental groups. This increase was more evident in the 48 h group. At 8 days after the last injection, there was a significant decrease in the density of the MCs compared to the 12 and 48 h groups. Alterations in pro-inflammatory cytokines were significant for all timeframes. This increase was more evident in the 48 h group after the last injection. There was a significant decrease in both neuroinflammatory cytokines at 8 days after the last injection. It was found that ethylmercury caused abnormal neurogenic inflammatory reactions and alterations in the neuroimmune cells that remained for a longer period in the brain than in the blood.