Effects of dietary lycopene on the protection against oxidation of muscle and hepatic tissue in finishing pigs

Research Progress on Lycopene in Swine and Poultry Nutrition: An Update

Oxidative stress and in-feed antibiotics restrictions have accelerated the development of natural, green, safe feed additives for swine and poultry diets. Lycopene has the greatest antioxidant potential among the carotenoids, due to its specific chemical structure. In the past decade, increasing attention has been paid to lycopene as a functional additive for swine and poultry feed. In this review, we systematically summarized the latest research progress on lycopene in swine and poultry nutrition during the past ten years (2013-2022). We primarily focused on the effects of lycopene on productivity, meat and egg quality, antioxidant function, immune function, lipid metabolism, and intestinal physiological functions. The output of this review highlights the crucial foundation of lycopene as a functional feed supplement for animal nutrition.

Lycopene Affects Intestinal Barrier Function and the Gut Microbiota in Weaned Piglets via Antioxidant Signaling Regulation

BACKGROUND

In pig production, early and abrupt weaning frequently causes weaning stress, which manifests as oxidative damage, barrier disruption, and digestion and absorption capacity declines. Lycopene exhibits beneficial antioxidant capacity in both humans and other animal models.

OBJECTIVES

The present study aimed to investigate the effects of lycopene supplementation on early weaning stress in piglets and the underlying mechanisms by examining the oxidative stress state, gut intestinal barrier function, and the gut microbiota.

METHODS

Twenty-four 21-day-old weaned piglets [Duroc × (Landrace × Yorkshire); castrated males; 5.48 ± 0.10 kg initial body weight] were randomly assigned to 2 treatments. The piglets were fed a basal diet (control treatment) or a basal diet supplemented with 50 mg/kg lycopene (lycopene treatment) for 28 days. The serum lipid levels, serum and jejunum enzyme activities, jejunum morphology, mRNA and protein expression, and gut microbiota were determined.

RESULTS

Compared with the control treatment, lycopene supplementation increased the serum catalase activity (P = 0.042; 62.0%); serum total cholesterol concentration (P = 0.020; 14.1%); and jejunum superoxide dismutase activity (P = 0.032; 21.4%), whereas it decreased serum (P = 0.039, 23.0%) and jejunum (P = 0.047; 20.9%) hydrogen peroxide concentrations. Additionally, lycopene increased the mRNA and protein expression of NFE2-like bZIP transcription factor 2 (214.0% and 102.4%, respectively) and CD36 (100.8% and 145.2%, respectively) in the jejunum, whereas it decreased the mRNA and protein expression of Kelch-like ECH-associated protein 1 (55.6% and 39.8%, respectively ). Lycopene also improved jejunal morphology, increasing the villus height (P = 0.018; 27.5%) and villus:crypt ratio (P < 0.001; 57.9%). Furthermore, it increased the abundances of potentially beneficial bacterial groups, including Phascolarctobacterium and Parasutterella, and decreased those of potentially pathogenic bacterial groups, including Treponema_2 and Prevotellaceae_unclassified.

CONCLUSIONS

Lycopene supplementation strengthens the intestinal barrier function and improves the gut microbiota in weaned piglets by regulating intestinal antioxidant signaling.

Lycopene improves maternal reproductive performance by modulating milk composition and placental antioxidative and immune status

Placental health and milk quality are important for maternal reproductive performance during pregnancy and lactation. Lycopene plays an important role in antioxidation, anti-inflammation and regulating lipid metabolism. The goal of the present study was to investigate the effects of dietary lycopene supplementation in the pig model on reproductive performance, placental health and milk composition during maternal gestation and lactation. In the present study, the litter size of live piglets was increased and the litter size of dead piglets was decreased by lycopene supplementation of the diet of sows. The litter weight at birth and weaning were increased in the lycopene group. Through placental proteomics, we enriched differentially expressed proteins (DEPs), gene ontology (GO) terms, and Kyoto encyclopedia of proteins and genomes (KEGG) pathways involved in immunity, anti-inflammation, antioxidants, and lipid metabolism and transport. Furthermore, in terms of placental health, we analyzed the levels of related enzymes, metabolites and mRNA expression in the placenta. Lycopene was shown to reduce mRNA expression and the levels of placental inflammatory factors, increase the content of immunoglobulin, improve the antioxidant capacity, and improve lipid metabolism and lipid transport in the placenta. In terms of sow milk composition, lycopene increased the levels of immunoglobulins in colostrum and lactose in colostrum and milk. Overall, the results of the present study demonstrate that dietary lycopene supplementation of sows during gestation and lactation improves the reproductive performance to a certain extent; this may be due to lycopene improving the placental health and milk composition of sows.