(P25-003-23) Raspberries Favorably Mediate Redox Enzymes in the Liver of Angiotensin II-Infused Rats

Objectives: It has been suggested that angiotensin (Ang) II play a substantial role in liver oxidative stress, inflammation, and fibrogenesis. Polyphenolic compounds which are found in berries have been shown to interact with molecular targets and prevent and/or mitigate these effects. Thus, we aim to investigate whether diet supplementation with raspberry (RB) attenuates the Ang II-induced increase in oxidative stress in the liver of rats.

Methods: Eight-week-old male Sprague-Dawley rats were fed either a control diet (AIN-93M) or a 10% RB-supplemented diet for seven weeks. At the end of week four, rats were implanted with subcutaneous osmotic minipumps that delivered 0.9% saline (control) or Ang II (270 ng/kg body weight/min). At week seven, rats were sacrificed and livers were excised. Protein expression of cytoprotective enzymes such as heme oxygenase (HO)-1, NADPH quinone oxidoreductase (NQO)1, catalase (CAT), superoxide dismutase (SOD) 1 and SOD2, as well as pro-oxidant enzymes xanthine oxidase (XO) and NADPH oxidase (NOX) 2 were measured by western blot. Data were analyzed by one-way ANOVA followed by Tukey’s post-hoc analysis for multiple comparisons.

Results: NOX2 expression was significantly increased by Ang II infusion compared to control (P = 0.04); however, RB supplementation did not prevent this effect. Conversely, RB attenuated the increase in XO (0.70 ± 0.10 vs 1.50 ± 0.41, P = 0.006) induced by Ang II. Compared to control, SOD2 was significantly reduced in Ang II-infused animals with (P = 0.01) and without RB supplementation (P = 0.01). However, NQO1 was significantly increased in RB-supplemented animals compared to Ang II alone (0.82 ± 0.24, P = 0.002) and control (P = 0.02). The peroxidase, CAT, was significantly decreased with Ang II compared to control (0.64 ± 0.15, P = 0.007) and RB consumption (0.88 ± 0.10, P = 0.03). No significant differences were observed in GPx1 expression (P = 0.28).

Conclusions: Our results suggest the potential for RB to mitigate oxidative stress induced by Ang II in the liver by reducing pro-oxidant enzymes and increasing antioxidant defense.

Funding Sources: This work is supported by the Agriculture and Food Research Initiative (grant no. 2019-67017-29257/project accession no. 1018642) from the USDA National Institute of Food and Agriculture.