Immune modulating activity of Maillard reaction products from milk proteins with lactose by nitric oxide reduction on macrophage

Caseins and whey proteins constitute most of the milk proteins. Also, lactose is the most abundant sugar in milk. The Maillard reaction makes the chemical compounds using reducing sugars and amino acids by non‐enzymatic reactions. The macrophages are participating in the initiation of inflammation, and they are activated by numerous inflammation factors, lipopolysaccharide (LPS), cytokines and other chemical factors. The activated macrophages synthesize nitric oxides for further anti‐inflammation processes. Using sodium caseinate and whey protein concentrate with lactose, we made Maillard reaction products (MRPs) as lactose‐sodium caseinate (LSC) and lactose‐whey protein concentrate (LWPC). The reaction was conducted with 120°C for 20 minutes in 0.1M sodium phosphate buffer solution, proteins (sodium caseinate or whey protein concentrate) and lactose ratio was 1:2 (w:w). As a result, the fluorescence of MRPs was increased and we confirmed by SDS‐PAGE that high molecular weight proteins were generated. Also, an intermediate in the Maillard reaction, hydroxymethylfurfural (HMF) was increased. Macrophage cells were produced more nitric oxide with sodium caseinate and whey protein concentrate, but lactose MRPs of each proteins are reduce nitric oxide level below the LPS‐induced nitric oxide level. Using RT‐PCR method, cytokine levels of IL‐1β and IL‐8 were also measured.