AMELIORATIVE EFFECTS OF SAFRANAL AND N-ACETYLCYSTEINE ON NEURO- AND BIOCHEMICAL DYSFUNCTION INDUCED BY HYPERTHYROIDISM IN THE BRAIN OF ADULT MALE ALBINO RATS

Abstract

THs are involved in the regulation of numerous body functions, including lipid and carbohydrate metabolism, oxygen consumption and numerous physiological processes such as development, reproduction and growth. Hyperthyroidism cause many health problems e.g. cardiovascular and hepatocellular complications. For a long time, the brain was believed to be unresponsive to THs. However, THs receptors were detected in human and rat brain. Besides the crucial role of thyroid hormones in brain development and physiology, recent investigations have highlighted the involvement of these hormones in affecting the characteristics of various neurotransmitter systems and neurotransmission. By binding to nuclear receptors and modulating gene expression, thyroid hormones influence neuronal migration, differentiation, myelination, synaptogenesis and neurogenesis in developing adult brains. The mechanism underlying brain dysfunction that results from thyroid disorders is still vague. Oxidative stress, lipid peroxidation and cellular apoptosis are the major culprits. Several antioxidant or anti-apoptotic agents have been used to ameliorate hyperthyroidism-induced brain dysfunction. N-Acetylcysteine (NAC) crosses the blood brain barrier (BBB), replenishes brain GSH and augments neurogenesis of neuronal stem cells and maintains neuronal persistence. NAC is now emerging as a treatment of neurological disorders. Safranal is a volatile compound and is one of the main active constituents of saffron. The potent significance of safranal as an antioxidant agent in biol