Immune-enhancing activity of phosvitin by stimulating the production of pro-inflammatory mediator

Abstract

Egg yolk phosvitin is one of the most phosphorylated proteins in nature, and the extraordinarily high concentration of phosphate groups in its structure provides a strong metal-binding ability. Phosvitin is known to possess various functional activities, including metal-chelating, antioxidant, emulsifying, antimicrobial, and cytotoxic activities. However, little is known about the immune-enhancing activity of phosvitin. The objective of this study was to evaluate the immune-enhancing activity of phosvitin in murine RAW 264.7 macrophages. Griess reagents and quantitative real-time PCR were used to determine the effect of phosvitin (at 12.5, 25, 50, and 100 μg/mL) on the levels of pro-inflammatory mediators NO and inducible nitric oxide synthase (iNOS), cytokines TNF-α and IL-1β in RAW 264.7 macrophages. The effect of phosvitin on the phagocytic activity of RAW 264.7 macrophages was also measured using the Neutral-Red Uptake method. Lipopolysaccharides was used as a positive control. Phosvitin significantly (P < 0.05) increased the production of NO in RAW 264.7 macrophages in a dose-dependent manner, but did not show any cytotoxicity. The amounts of NO produced were 3.47, 7.12, 10.23, and 14.57 μM in 12.5 to 100 μg/mL range of phosvitin (control: 0.46 μM). Compared with the untreated group, phosvitin treatment at a 100 μg/mL level increased the production of NO by 31.67 times. Phosvitin also significantly increased the mRNA expression of the RAW 264.7 macrophages: 100 μg/mL of phosvitin treatment increased the expression of mRNA for iNOS, TNF-α, and IL-1β by 46.25, 9.09, and 85.18 times of the control, respectively. The phagocytic activity of RAW 264.7 macrophages was also increased significantly by phosvitin treatment. These results demonstrated that phosvitin dramatically improved the immune functions RAW 264.7 macrophages by enhancing the production of immune mediators and increasing phagocytic activity. Therefore, phosvitin has a potential to be used as an immune-enhancing agent by food or nutraceutical industries.

The Influence of Nutrients on Inflammatory Bowel Diseases

“…In addition, the compound inhibited the expression of other proinflammatory cytokines (IL-8 and IL-12) [129]. Lee et al presented in their work the action of phosvitin increasing the phagocytic activity of macrophages in vitro [130]. Li et al presented the effect of phosvitin on intestinal microflora in animal models.…”

Ovalbumin Hydrolysates Inhibit Nitric Oxide Production in LPS-induced RAW 264.7 Macrophages

“…The MTT assay (Lee et al, 2017b) was used for determining the effects of OVA and OVA hydrolysates on cell viability of RAW 264.7 cells. After measuring NO concentration in the medium, an aliquot of the MTT solution (2.5 mg/mL) was added to each well and incubated for an additional 4 h. Supernatants were removed, and dimethyl sulfoxide was added to the wells to dissolve the formazan crystals.…”

“…Macrophages play a vital role in immune reactions, and the functions of macrophages that include phagocytosis, antigen presentation, and NO and inflammatory cytokine production (Lee et al, 2017b). Macrophages produce pro-inflammatory factors via several cell signaling pathways, including nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) pathways when they are activated by lipopolysaccharides (LPS), which are one of the main sources of stimulation for macrophages (Ham et al, 2015;Li et al, 2017).…”

Review article: emulsifiers in the food supply and implications for gastrointestinal disease

“…It is presumed that the mucosal inflammation that is associated with the exposure of emulsifiers and thickening agents in animal models is a direct consequence of the alteration of barrier function and of increased aggressiveness of bacteria with greater translocation. However, some proteins with strong emulsifier activity, such as egg‐yolk phosvitin, have direct effects on a macrophage‐like cell line by increasing nitric oxide production and increasing phagocytosis in a dose‐dependent manner . The in vivo significance of this is unknown.…”