Physiological and Biochemical Effects of Echium Amoenum Extract on Mn2+-Imposed Parkinson Like Disorder in Rats

Purpose: Manganism is a cognitive disorder take places in peoples are exposed to environmental manganese pollution. Overexposure to manganese ion (Mn2+) mainly influences central nervous system and causes symptoms that increase possibility of hippocampal damages. Methods: In this study rats were administrated by two different doses of MnCl2 and behavioral and physiological consequences were evaluated. We also investigated effects of E. Amoenum on Mn2+-imposed toxicity by behavioral, biochemical, immunoblotting and histological studies on hippocampus tissue. Results: Results showed metal overexposure increases oxidative stress mainly by lipid peroxidation and reactive oxygen species overproduction. Histological studies and caspase 3 analyses by immunoblotting revealed Mn2+ induced apoptosis from mitochondrial-dependent pathway in the presence of low metal dose. This study provides evidence that oral administration of E. amoenum extract inhibited manganese neurotoxicity by oxidative stress attenuation and apoptosis reduction that lead to improved depression like behavior. Plant extract also increased catecholamine content in Mn2+ treated hippocampus. Conclusion: As molecular and pathophysiological effects of E. amoenum, it could be considered as a pre-treatment for Parkinson and Parkinson like disorders in high-risk people.

Antidepressant behavior in thyroidectomized Wistar rats is induced by hippocampal hypothyroidism

Thyroidectomy is a surgical procedure indicated in cases of several maligned or benign thyroid diseases, thus, the aim of our study was to verify how the hypothyroidism induced by thyroidectomy influences behavioral parameters and its relation to thyroid hormones metabolism and neurogenesis at hippocampus. For this purpose, Adult male Wistar rats underwent to thyroidectomy to induce hypothyroidism. Behavioral tests, the thyroid profile and hippocampal gene expression were evaluated in control and in thyroidectomized animals. It was observed that thyroidectomized group had a significant increasing in serum thyroid-stimulating hormone (TSH) and a decreasing in thyroxine (T4) levels as well as in triiodothyronine (T3) serum level. It was also observed reduction of the monocarboxylate transporter 8 (Mct8), thyroid hormone receptor alfa (Trα1), deiodinase type 2 (Dio2), ectonucleotide pyrophosphatase/phosphodiesterase 2 (Enpp2) and brain-derived neurotrophic factor (Bdnf) mRNA expression in hippocampus of thyroidectomized animals. In the forced swimming test, it was verified that thyroidectomy promotes a decrease in time of immobility and climbing when compared with the control group. In summary, we demonstrated that antidepressant behavior in thyroidectomized Wistar rats is induced by hippocampal hypothyroidism. This effect could be associated to an impaired neuronal activity in acute stress response as it is observed in forced swimming paradigm.