Zinc coadministration attenuates melatonin’s effect on nitric oxide production in mice

Abstract

Both melatonin (MEL) and zinc (Zn) are considered beneficial for anti-immunosenescence. MEL's effects on immune functions are partly attributed to an interaction with Zn. However, the augmentation of or interference with MEL's effects by coadministration of Zn remains unclear. In this study, adult older mice received either MEL (10 microg/mL), Zn (22 microg/mL), MEL+Zn, or null supplementation from drinking water for 3 mo. The results showed that treated mice, irrespective of the type of added chemicals, had higher body-weight gain and body-fat content than control mice. MEL- and Zn-treated mice also had increased serum free fatty acid levels. In addition, the MEL group had decreased serum NOx (nitrite+nitrate) values. Serum tumor necrosis factor-alpha levels were increased, although nonsignificantly, in mice that received either MEL or Zn supplementation. However, the differences described were not retained in the mice that received MEL+Zn treatment. We conclude that a high-dose Zn coadministration might exert negative influences on MEL's regulatory effects, at least on nitric oxide production.

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

“…In fact, it has been established that melatonin supplementation has decreased the serum nitrite and nitrate levels. 13 However, it is stated that melatonin and zinc supplementation negatively affects the suppression on NO levels formed by melatonin. Although NO is defined as a mediator of especially the post I/R glutamate toxicity, it has been determined that melatonin supplementation decreases the brain NO production by suppressing NO synthetase.…”

“…12 Application of zinc together with melatonin suppresses the effect that melatonin creates in NO production. 13 It was reported that melatonin treatment prevented cell apoptosis and necrosis in parallel with lipid peroxidation. 14 Zinc is also a strong antioxidant and it is acknowledged that it reduces oxidative stress and has neuroprotective effects.…”

Phenotype of the neural tube defect mouse model bent tail is not sensitive to maternal folinic acid, myo‐inositol, or zinc supplementation

“…There were no adverse effects if 0.5 mg ZnCl 2 (corresponding to 0.24 mg zinc) per day was given with the drinking water. We used this amount in our study because even lower amounts of zinc (0.11 mg per day) had shown physiological effects in a study evaluating the effect of melatonin on the production of nitric oxide in the mouse (Chen et al, 1999). A search of the literature yielded no data regarding the effect of a zinc surplus on NTDs in mice or rats.…”

Zinc in Attention-Deficit/Hyperactivity Disorder

“…In this form, vitamin B6 is necessary for the conversion of tryptophan to serotonin. Zinc is also necessary for the production and modulation of melatonin, which helps regulate dopamine function (Sandyk 1990;Chen et al 1999), which is widely believed to be a key factor in attention-deficit/hyperactivity disorder (ADHD) and its treatment. In fact, Sandyk (1990) hypothesized that parasympathomimetic stimulants, at least amphetamine, work in ADHD partly through their effects on melatonin.…”