Monochromatic green and blue light stimulated fat production in the liver and abdominal fat tissue of broilers

1. This study evaluated the effects of monochromatic lights on lipid metabolism, inflammation and antioxidant capacity in broilers. Eighty newly hatched broilers were assigned to four treatment groups (n = 20/group) and exposed to white (400–700 nm), red (660 nm), green (560 nm), or blue (480 nm) LED light for 35 d.2. Abdominal adipose tissue histology, tissue weight, plasma hormones, blood biochemistry, lipid metabolism gene/protein expression, antioxidant activity and inflammatory levels were assessed.3. Green and blue light exposure increased abdominal adipose tissue weight, adipocyte size and relative area of lipid droplets (p < 0.05). These groups exhibited elevated high-density lipoprotein cholesterol (HDL-C), adiponectin (adipoQ), very low-density lipoprotein (VLDL) and Triglyceride (TG) levels (p < 0.05), concurrent with reduced free fatty acid (FFA) concentrations in plasma and adipose tissue.4. Green and blue light increased fat synthesis gene expression (Scd1andSrebp1; p < 0.05) while downregulating fatty acid (FA) uptake genes (Cd36; p < 0.001), FA β-oxidation genes (Cpt-1andPPARα; p < 0.05) and lipid export genes (ApoB; p < 0.05) in the liver. Additionally, blue light significantly inhibited lipolysis-related genes (ATGL, HSL, LPL; p < 0.001) to a greater extent than it affected fat synthesis compared with white light in abdominal adipose tissue.5. Both green and blue lights upregulated anti-inflammatory factors (IL-4, IL-10; p < 0.05), elevated glutathione (GSH), total glutathione (T-GSH) and oxidised glutathione/glutathione (GSSG/GSH) ratios (p < 0.05) and reduced malondialdehyde (MDA) levels (p < 0.001) and pro-inflammatory markers (IL-6, IL-1β, TNF-α) (p < 0.05). Notably, green light treatment had the highest total antioxidant capacity (T-AOC) in the liver and abdominal adipose tissues.6. The results suggested exposure to monochromatic blue and green light leads to lipid accumulation, decreased inflammation and improved antioxidant capacity and green light may offer superior protection against oxidative stress.