Milk nutrition and childhood epilepsy: An ex vivo study on cytokines and oxidative stress in response to milk protein fractions.

ABSTRACT

We present a pilot study on the effects of milk protein fractions [αS1-casein (CN), αS2-CN, κ-CN, ß-CN, and a mix of α-lactalbumin (α-LA) and ß-lactoglobulin (ß-LG)] from different animal species (bovine, ovine, and caprine) on pro- and anti-inflammatory cytokines and oxidative status in cultured peripheral blood mononuclear cells from children with generalized epilepsy. Peripheral blood mononuclear cells (PBMC) were obtained by density gradient from blood of 10 children with generalized epilepsy (5 males; mean age 33.6 ± 5.4 mo) and 10 controls (5 males; mean age 35.6 ± 6.8 mo). Children with epilepsy were grouped according to cytokine levels as follows children with epilepsy having low levels of cytokines not different from those of control children (LL-EC); children with epilepsy having cytokine levels at least 5-fold higher (medium levels) than those of control children (ML-EC); and children with epilepsy having cytokine levels at least 10-fold higher (high levels) than those of control children (HL-EC). The production of tumor necrosis factor-α (TNF-α), IL-10, IL-6, and IL-1ß was studied in cultured PBMC incubated with αS1-CN, αS2-CN, κ-CN, ß-CN, and a mix of α-LA and ß-LG from bovine, caprine, and ovine milks. The levels of reactive oxygen and nitrogen species (ROS/RNS) and catalase activity were assessed in cultured supernatant. In the HL-EC group, ß-CN from small ruminant species (ovine and caprine) induced the highest levels of TNF-α, whereas PBMC incubated with αS2-CN from ovine milk and the mix of ß-LG and α-LA from all tested milk species had the lowest levels of TNF-α. Within the HL-EC group, production of IL-1ß was higher for bovine and ovine αS2-CN fractions and lower for caprine and ovine ß-CN and κ-CN. In the HL-EC group, IL-6 was higher in cultured PBMC incubated with αS2-CN from bovine and ovine milk than from caprine milk. The cytokine IL-10 did not differ among milking species. The highest levels of ROS/RNS were found after incubation of PBMC with the ß-CN fraction in bovine milk. Catalase activity was higher in PBMC cultured with ß-CN isolated from bovine and caprine milk and with αS1-CN from ovine milk.