BackgroundResveratrol, a plant phenol, affords protection against inflammation and oxidative stress. The objective of this study was to investigate the effects of dietary resveratrol supplementation during pregnancy and lactation on the antioxidant status of sows and piglets and on antioxidant gene expression and pathway in placenta.MethodsForty sows were allotted to 2 dietary treatments 20 d after breeding. Sows were fed a control diet and a control diet with 300 mg/kg resveratrol. Oxidative stress biomarkers and antioxidant enzymes were measured in the placenta, milk, and plasma of sows and piglets. Antioxidant gene expression and protein expression of Kelch-like ECH-associated protein 1-Nuclear factor E2-related factor 2 (Keap1-Nrf2), nuclear factor kappa B-p65 (NFκB-p65) and sirtuin1 (Sirt1) were quantified in the placenta.ResultsDietary resveratrol increased the litter and piglets weaning weights. Antioxidant status in the milk, placenta and plasma of sows and piglets was partially improved by dietary resveratrol. In placenta, Nrf2 protein expression was increased and Keap1 protein expression was decreased by dietary resveratrol. The mRNA expression of antioxidant genes including catalase (CAT), glutathione peroxidase 1 (GPX1), GPX4, superoxide dismutase 1 (SOD1) and heme oxygenase 1 (HO1), and phase 2 detoxification genes, including glutamate-cysteine ligase modifier (GCLM), microsomal glutathione S-transferase 1(MGST1) and UDP glucuronosyltransferase family 1 member A1 (UGT1A1), was increased by dietary resveratrol. Dietary resveratrol also increased Sirt1 and phosphorylated NFκB-p65 protein expression in the placenta. We failed to observe any influences of dietary resveratrol on pro-inflammatory cytokine levels, including those of interleukin 1β (IL-1β), IL-6, IL-8 and tumor necrosis factor α (TNF-α). However, we observed that the mRNA expression of IL-8 in placenta was reduced by maternal resveratrol. In addition, dietary resveratrol showed interactive effects with day of lactation on activities of SOD and CAT and levels of malonaldehyde (MDA) and hydrogen peroxide (H2O2) in milk.ConclusionsDietary resveratrol supplementation during pregnancy and lactation improves the antioxidant status of sows and piglets, which is beneficial to the reproductive performance of sows. Dietary resveratrol regulates placental antioxidant gene expression by the Keap1-Nrf2 pathway and Sirt1 in placenta.

Low-density lipoprotein receptor (LDLR) has been demonstrated to play a central role in lipoprotein metabolism, with Ldlr-deficient (Ldlr(-/-)) mice developing severe dyslipidemia. In the present study we investigated whether Ldlr knockout could harm female reproduction and explored the mechanisms involved. The results indicate that although the number of litters born to Ldlr(-/-) mice did not differ significantly from that born to controls, the number of pups per litter was significantly lower in the former group. Interestingly, although Ldlr(-/-) mice were obese, the weight of their ovaries was lower than that in control mice. Serum cholesterol levels was significantly higher in Ldlr(-/-) mice than in their wild-type counterparts. In contrast, there were significant decreases in cholesterol, triglyceride and total lipid levels in ovaries of Ldlr(-/-) mice. Both ovarian lipid deposition, as detected by Oil red O staining, and lipid droplets, as evaluated by transmission electron microscopy, supported decreased lipid levels in ovaries from Ldlr(-/-) mice. In addition, Ldlr(-/-) mice had fewer ovarian follicles, more atretic follicles, lower oestrogen levels and spent significantly less time in oestrus than did the controls. Superovulation assays indicated immature Ldlr(-/-) mice ovulated fewer ova than controls. These results indicate that lack of Ldlr results in dyslipidaemia and poor fertility.

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