Inhibitory Effect of Known Antioxidants and of Press Juice from Herring (Clupea harengus) Light Muscle on the Generation of Free Radicals in Human Monocytes

Abstract

Reactive oxygen species (ROS) can cause oxidative stress, which has been linked to various diseases. It has been suggested that antioxidant-rich foods can reduce such oxidative stress. However, the lack of suitable model systems to screen for in vivo effects of food-derived antioxidants has prevented a clear consensus in this area. In this study, the aim was to use a single-cell model system (human monocyte) to evaluate whether certain pure antioxidants and complex muscle extracts (herring light muscle press juice, PJ) could prevent ROS formation under in vivo like conditions. ROS were excreted from the monocytes upon stimulation with phorbol myristate acetate and were then detected as isoluminol-enhanced chemiluminescence (CL). Adding 2000 units of catalase and 50 units of superoxide dismutase to the monocytes model lowered the CL response by 35 and 86%, respectively. Ascorbate (14.1 mM) lowered the response by 99%, alpha-tocoperhol (188 microM) by 37%, and Trolox (50 microM) by almost 100%. Crude herring PJ gave a dose-dependent reduction in the CL response. At 10, 100, and 1000 times dilution, the PJ reduced the CL signal by 93, 60.5, and 10.6%. PJ fractionated into low molecular weight (LMW) (<1000 Da) and high molecular weight (>3500 Da) fractions decreased the CL response by 52.9 and 71.4%, respectively, at a 100-fold dilution. Evaluation of the PJ samples in the oxygen radical absorbance capacity test indicated that proteins may be the primary radical scavenging compounds of PJ, whereas the ROS-preventing effect obtained from the LMW fraction may also be attributed to other mechanisms. Thus, this study proved that the monocyte assay can be a useful tool for studying whether food-derived antioxidants can limit ROS production under physiologically relevant conditions. It also showed that herring contains numerous aqueous compounds demonstrating antioxidative effects in the monocyte model system.

Changes in the Antioxidative Property of Herring (Clupea harengus) Press Juice during a Simulated Gastrointestinal Digestion

“…The LMPJ sample at the start of digestion had numerous bands ranging from 181 kDa to below 5 kDa size (Figure 4, lane 1). This was in accordance with Gunnarsson et al (6), who reported herring PJ to comprise many peptides distributed over a broad range of molecular size. The supernatant resulting from centrifugation of the 0 min digested LMPJ sample also had numerous bands (Figure 4, lane 2), showing that most of its proteins/peptides were soluble.…”

Herring (Clupea harengus) intake influences lipoproteins but not inflammatory and oxidation markers in overweight men

“…Intake of such antioxidants in a fish meal could theoretically help prevent oxidative stress in the body, caused by the easily oxidised n -3 PUFA. The liquid fraction (press juice) from herring was found to prevent oxidation in a food system ( 6 ) and to have antioxidative effects in a human monocyte model system ( 7 ) . Second, fish contains high concentrations of Se, which has been related to a reduced risk of CVD ( 8 , 9 ) .…”

Antioxidative Properties of Press Juice From Herring (Clupea harengus) Against Hemoglobin (Hb) Mediated Oxidation of Washed Cod Mince

“…This table is reproduced from Gunnarson et al(19); however, additional statistical treatment is included.…”