Melatonin increases gene expression for antioxidant enzymes in rat brain cortex

Abstract

During the last years several reports have demonstrated that melatonin is a efficient free radical scavenger and general antioxidant. In addition, it has been shown that this neurohormone is able to increase the activity of glutathione peroxidase in rat brain cortex as well as the gene expression for some antioxidant enzymes in the Harderian gland of female Syrian hamster. Also, it is well known that brain cells are particularly exposed to free radicals, with antioxidant enzymes as the major defense mechanism that the brain uses to neutralize reactive oxygen species. The aim of the present study was to examine the influence of melatonin on gene expression for antioxidant enzymes in rat brain cortex. Our results clearly demonstrate that exogenously administered melatonin increases the levels of mRNA for glutathione peroxidase, copper-zinc superoxide dismutase, and manganese superoxide dismutase in this tissue. These stimulatory effects are observed after both acute and chronic treatment with this hormone, producing in the latter case the more marked increase. We therefore conclude that melatonin exerts an important role in providing indirect protection against free radical injury by stimulating gene expression for antioxidant enzymes. Consequently, melatonin could be considered as a potential therapeutic agent in some age-related neurodegenerative diseases where excessive free radical production has been implicated.

The effects of prophylactic zinc and melatonin application on experimental spinal cord ischemia–reperfusion injury in rabbits: experimental study

“…15 Parallel to these, it was suggested that melatonin supplementation causes the antioxidant characteristic to emerge by increasing plasma zinc levels 32 and at the same time by increasing Cu-Zn-SOD activity. 33 When the part of the study related to NO was evaluated, I/R procedure did not result with significant difference in NO levels. This situation may be the result of the shortness of I/R period.…”

Melatonin and ubiquitin: what’s the connection?

“…Melatonin has been reported to increase tissue levels of glutathione peroxidase [66,67], an enzyme that metabolizes glutathione (an antioxidant) to its oxidized form [68] and to increase the mrna for glutathione peroxidase [69,70] in the rat brain. the possible interaction of ubiquitin in this effect of melatonin has not been directly tested.…”

Mitochondrial Disorders Therapy: The Utility of Melatonin~!2009-11-18~!2010-01-21~!2010-06-23~!

“…It has been reported that melatonin can increase the SOD and catalase activities and induces the expression and activity of GPx and GRd, regulating the redox cycle of glutathione [142][143][144][145][146][147]. The regulation of glutathione system by melatonin is also reflected by the stimulation of the rate limiting enzyme in glutathione synthesis, γ-glutamylcysteine synthase [148].…”