Effects of Melatonin Supplementation during Pregnancy on Reproductive Performance, Maternal–Placental–Fetal Redox Status, and Placental Mitochondrial Function in a Sow Model

Abstract

Melatonin (MT) is a bio-antioxidant that has been widely used to prevent pregnancy complications, such as pre-eclampsia and IUGR during gestation. This experiment evaluated the impacts of dietary MT supplementation during pregnancy on reproductive performance, maternal–placental–fetal redox status, placental inflammatory response, and mitochondrial function, and sought a possible underlying mechanism in the placenta. Sixteen fifth parity sows were divided into two groups and fed each day of the gestation period either a control diet or a diet that was the same but for 36 mg of MT. The results showed that dietary supplementation with MT increased placental weight, while the percentage of piglets born with weight < 900 g decreased. Meanwhile, serum and placental MT levels, maternal–placental–fetal redox status, and placental inflammatory response were increased by MT. In addition, dietary MT markedly increased the mRNA levels of nutrient transporters and antioxidant-related genes involved in the Nrf2/ARE pathway in the placenta. Furthermore, dietary MT significantly increased ATP and NAD+ levels, relative mtDNA content, and the protein expression of Sirt1 in the placenta. These results suggested that MT supplementation during gestation could improve maternal–placental–fetal redox status and reproductive performance by ameliorating placental antioxidant status, inflammatory response, and mitochondrial dysfunction.

Melatonin Supplementation during the Late Gestational Stage Enhances Reproductive Performance of Sows by Regulating Fluid Shear Stress and Improving Placental Antioxidant Capacity

“…In this study, it is found that melatonin supplementation does not modify levels of blood progesterone and estrogen. The results are similar to that reported by Peng et al, and Lv et al [ 22 , 31 ]. In addition, energy metabolism and cortisol level are also important factors for the reproductive performance of animals [ 32 , 33 ].…”

“…For example, in sheep, the subcutaneous embedding of melatonin promoted the growth and development of lambs [ 29 ]. As mentioned above, Peng et al, gave melatonin to early gestated sows and also tested their oxidative stress responsibility [ 22 ]. Their study seems to have some similarities to ours.…”

“…Renshall et al, have reported that in mice with normal pregnancy, melatonin supplementation between days 12.5 and 18.5 of the gestation stage also increases fetal birth weight [ 21 ]. Recently, Peng et al, supplemented melatonin to sows from the period of fertilization to parturition [ 22 ]. They observed that the proportion of piglets with birth weight <900 g was reduced, but the average birth weight of piglets exhibited no significant difference compared to the control.…”

Endocrine disorders and fertility and pregnancy: An update

“…Melatonin deficiency is correlated with decreased fertility ( 29 , 30 ), lower levels of sex steroid hormones ( 30 ), and decreased survival of embryos after fertilization ( 31 ). At the same time, a positive correlation was observed between serum melatonin concentration and fertility ( 32 – 36 ). Administration of exogenous melatonin is associated with a higher percentage of maintained pregnancies ( 37 ).…”

Antioxidants in Animal Feed

“…Melatonin is considered as a bio-antioxidant. Peng et al evaluated the impacts of dietary melatonin supplementation during pregnancy on reproductive performance, maternal–placental–fetal redox status, placental inflammatory response and mitochondrial function [ 2 ]. They concluded that melatonin supplementation during gestation could improve maternal–placental–fetal redox status and reproductive performance by ameliorating placental antioxidant status, inflammatory response and mitochondrial dysfunction.…”