Effect of casein supplementation on HBD-1, Th-17 and IL-22 in a preterm Rattus norvegicus chorioamnionitis model

Purpose: To investigate casein's role in the expressions of human beta-defensin (HBD)-1, T helper subset (Th)-17, and interleukin (IL)-22 in preterm Rattus norvegicus (RNs). Methods: Twenty-four healthy, first-time pregnant RNs were divided into three groups (G). Group 1 (G1) received regular casein (R) 0.4 g/RN/day, while G2 and G3 received casein supplementation (S) 2 g/RN/ day. Each RN was given 10 g of food and drank 10 mL. On day 10, a single intraperitoneal lipopolysaccharide (LPS) was injected with 100 g/kg body weight. Lipopolysaccharide was injected into G3 as a premature model with chorioamnionitis. Histopathological examination was carried out to measure the expression of HBD-1, Th-17, and IL-22 using methyl green counterstaining. Chorioamnion specimens were taken and fixed in 4 % paraformaldehyde, and then evaluated by immunohistochemical (IHC) procedures to obtain immunoreactive score (IMS). Results: The IMS expression of HBD-1 in G1 was 1.187 ± 0.372, while G3 was 9.562 ± 2.351 (p < 0.05). Th-17 expression were G1: 2.062 ± 0.140, G2: 6.122 ± 1.347, and G3: 9.112 ± 2.019 (p < 0.05). Furthermore, IL-22 expressions were G1: 1.825 ± 0.468, G2: 4.700 ± 1.614, and G3: 7.800 ± 1.669 (p < 0.05). Conclusion: Casein supplementation increases HBD-1, Th-17, and IL-22 expression in preterm RN and in the LPS-induced RN chorioamnionitis model. The increase in HBD-1, Th-17, and IL-22 indicate that casein plays a role in the protection and control of chorioamnionitis tissue inflammation.