Melatonin scavenges phenylglyoxylic ketyl radicals.
The antioxidant properties of melatonin were tested in this work by EPR technique. It was found that melatonin scavenges phenylglyoxylic ketyl radicals. Its effectiveness was 10-times lower than that of vitamin C. A new method of generation of phenylglyoxylic ketyl radicals by spontaneous decomposition of D,L-2,3-diphenyltartaric acid in propan-2-ol was used.
Melatonin and the Pineal Gland
&NA; The pineal gland is an enigma within the central nervous system that appears to exert tremendous control over the homeostatic mechanisms of the body. In the animal kingdom, the pineal gland and the hormone it produces, melatonin, regulate circadian rhythms, sleep‐wake cycles, thermal and immunologic systems, and reproductive capability. Human research has demonstrated that the pineal gland also plays a role in sleep disturbances, menstrual and reproductive irregularities, psychological and behavioral disorders, and may even serve as a tumor inhibitory gland. Although research is still in the early stages, it is apparent that the pineal gland and melatonin have widespread effects and optimal functioning of the pineal gland is essential to our well‐being.
Neonatal pinealectomy impairs murine antibody-dependent cellular cytotoxicity
The pineal gland, through its principal hormone melatonin, is able to modulate different immune functions. We have previously demonstrated that exogenous melatonin induces a significant enhancement of murine antibody-dependent cellular cytotoxicity (ADCC). In order to determine whether the pineal gland plays a physiological role in ADCC regulation, we studied the influence of neonatal pinealectomy on this activity. The results presented here indicate that ablation of the pineal gland during the first week of life significantly reduces ADCC levels in adult mice. This impairment appears around 60 days of age, suggesting that sexual hormones may be involved in the pineal effect. Moreover, the administration of melatonin to pinealectomized mice restores ADCC levels regardless of the hour and seasonal time of injection. On the basis of the data reported here, a physiological regulation of ADCC by the pineal gland can be assumed.