## 3 Results and Discussion
### Cellular Immunomodulatory Activity
Values represent the mean \(\pm\) SEM of three independent experiments. Statistical analysis by ANOVA followed by Dunnett’s test. *, ***, and **** denote statistically significant difference in IL-6 production between sample and LPS control at \(p<0.05\), \(p<0.001\), and \(p<0.0001\), respectively. In a similar cell model, exposure of wheatgrass to LPS-stimulated THP-1 monocytes increased NO production along with increasing levels of inflammatory cytokines TNF-\(\alpha\), IL-6, IL-1\(\beta\) compared with the LPS control (\(p<0.05\)) [54]. Inflammatory compounds have been identified in numerous food components including fatty acids [55], polysaccharides [56], and protein sources [57; 58; 59]. Although the majority of immunomodulatory fish protein hydrolyses have been shown to mitigate proinflammatory mediators and cytokines, proinflammatory hydrolyses have been generated from giant croaker (_Nibea japonica_) and tilapia fish with the ability to increase inflammation mediators and cytokines in cellular systems [16; 17]. Intragastric administration of marine oligopeptide preparation from chum salmon (0, 0.22, 0.45, 1.35 g/kg bodyweight (BW), 4 weeks) did not activate macrophage cells, however innate and adaptive immunities were enhanced via the promotion of natural killer cell activity and stimulation of Th cells, thereby increasing the secretion of Th1 and Th2 cytokines [60]. In addition, a fermented fish protein concentration prepared from pacific whiting, which has been shown to increase immunoglobulin (Ig)A+ cells, secretory-IgA (S-IgA), and cytokines IL-4, IL-6, IL-10, IFN\(\gamma\), and TNF-\(\alpha\) upon oral administration to BALB/c mice (0.30 mg/mL, 7 days), is now commercially available as Seacure(r) [61]. The findings of the present study demonstrated that BW-SPH-F may act as a nonspecific immunositulant (i.e., not antigen specific) upon oral administration, with the potential to stimulate immune cells for therapeutic use in chronic infections, immunodeficiency, autoimmunity, and neoplastic diseases. The production of inflammatory mediators and cytokines must be regulated carefully, however, as excess secretion may negatively impact human health [62]. While previous studies have reported fish protein hydrolyses with antioxidant and anti-inflammatory properties [11; 63], we have identified hydrolysate BW-SPH-A herein, which exhibited antioxidant activities in oxidatively stressed RAW264.7 cells as well as proinflammatory effects in LPS-activated RAW264.7 cells. A study [64] concluded that tripeptide glutathione, which decreased LPS-induced ROS generation, also stimulated the production of NO and proinflammatory cytokines in RAW264.7 cells via nuclear factor-\(\kappa\)B (NF-\(\kappa\)B), mitogen-activated protein kinase (MAPK), and Notch signal pathways. Simi  
Figure 3: The effect of blue whiting soluble protein hydrolyses (BWSPHs) (BW-SPH-A–F) and simulated gastrointestinal digested (SGID) BWSPHs (BW-SPH-A-GI—F-GI) at 0.5% (\(w/v\) dry weight) on TNF-\(\alpha\) production in lipopolysaccharide-stimulated RAW 264.7 cells. RAW264.7 cells (0.2 \(\times\) 10\({}^{5}\) cells/mL, 200 \(\upmu\)L/well) were simultaneously exposed to 0.1 ug/mL LPS and BWSPHs or SGID BWSPHs for 24 h. Values were expressed as a percentage relative to positive control, cells treated with 0.1 ug/mL LPS alone (100% TNF- \(\alpha\) secretion). Values represent the mean \(\pm\) SEM of three independent experiments. Statistical analysis by ANOVA followed by [PERSON]’s test. * and *** denote statistically significant difference in TNF-\(\alpha\) production between sample and LPS control at \(p<0.05\) and \(p<0.0001\), respectively. # indicates a significant difference at \(p<0.05\) between pre- and post-SGID values measured by \(t\)-test. larly, bioavailable whey peptides obtained post-SGID inhibited free radicals in oxidatively stressed muscle and liver cells and increased the secretion of proinflammatory cytokine IL-1\(\beta\) from LPS-stimulated THP-1 macrophages [65].