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.
Subject(s)
Epilepsy, Generalized/metabolism , Leukocytes, Mononuclear/metabolism , Milk Proteins/metabolism , Oxidative Stress , Animals , Caseins/metabolism , Cattle , Cells, Cultured , Child, Preschool , Cytokines/metabolism , Epilepsy, Generalized/etiology , Female , Goats , Humans , Interleukin-10/metabolism , Interleukin-6/metabolism , Lactalbumin/metabolism , Male , Milk Proteins/adverse effects , Milk Proteins/analysis , Pilot Projects , Reactive Nitrogen Species/metabolism , Reactive Oxygen Species/metabolism , Sheep , Tumor Necrosis Factor-alpha/metabolismABSTRACT
The present study was undertaken to evaluate the effect of protein fractions from bovine, caprine, and ovine milk on production of cytokines and reactive oxygen species (ROS) and reactive nitrogen species (RNS) by cultured peripheral blood mononuclear cells (PMBC) from infants with generalized epilepsy. Bovine, caprine, and ovine bulk milks were pasteurized and analyzed for chemical composition. Then, PBMC were isolated from 10 patients with generalized epilepsy (5 males; mean age 33.6±5.4mo). Production of tumor necrosis factor-α (TNF-α), IL-10, IL-6, and IL-1ß was studied in cultured PBMC (from infants with epilepsy and controls) stimulated by bovine, caprine, and ovine milk and casein and whey protein fractions, and levels of ROS and RNS were measured in the culture supernatant. The ability of PBMC to secrete cytokines in response to milk and protein fraction stimulation may predict the secretion of soluble factor TNF-α in the bloodstream of challenged patients. Bovine, caprine, and ovine bulk milks induced low-level production of IL-10 by cultured PBMC in at least 50% of cases; the same behavior was observed in both casein and whey protein fractions for all species studied. Bovine and ovine milk and their casein fractions induced production of lower levels of IL-1ß in 80% of patients, whereas caprine milk and its casein fraction induced the highest levels in 80% of patients. The amount of IL-6 detected after stimulation of PBMC by milk and its fractions for all species was lower than that of other proinflammatory cytokines. In the bovine, total free radicals were higher in bulk milk and lower in the casein fraction, whereas the whey protein fraction showed an intermediate level; in caprine, ROS/RNS levels were not different among milk fractions, whereas ovine had higher levels for bulk milk and casein than the whey protein fraction. Lower levels of ROS/RNS detected in PBMC cultured with caprine milk fraction could be responsible for the lower levels of TNF-α cytokine in the corresponding fraction. Cytokines might be useful biomarkers to discriminate the effects of foods on the inflammatory response; dietary strategies could help in alleviating the negative effects of epilepsy in infants.
