(P03-026-23) Protective Effects of Raspberry Consumption on the Lung in Angiotensin II-infused Rats

Objectives: Oxidative stress plays a role in the development of chronic obstructive pulmonary disease. Angiotensin (Ang) II is a hormone that can promote oxidative stress via binding to the Ang II type-1 receptor in the lung. Epidemiological studies indicate that polyphenol intake is associated with improved lung function. Raspberries are a rich source of polyphenols; thus, their consumption may beneficially affect the lung. Thus, we aimed to assess the impact of a raspberry (RB) supplemented diet on Ang II-induced oxidative stress in the lung of rats.

Methods: Eight-week-old male Sprague-Dawley rats were fed AIN-93M (4% corn oil) diets with or without a 10% w/w RB freeze-dried powder for seven weeks. During week four, osmotic minipumps were implanted subcutaneously which delivered either 0.9% saline as a control, or Ang II (270 ng/kg/BW). During week seven, lungs were extracted, and the tissue was homogenized. The expression of pro-oxidant enzyme NAD(P)H oxidase (NOX)1 and antioxidant enzymes superoxide dismutase (SOD)1, SOD2, NAD(P)H quinone oxidoreductase (NQO)1 and catalase (CAT) were assessed via western blot. Protein expression was quantified and then analyzed with one-way ANOVA followed by Tukey post-hoc multiple comparisons analysis. Significance was deemed a P ≤ 0.05.

Results: The expression of superoxide (O₂-) producing NOX1 increased in animals treated with Ang II alone (P = 0.05) compared to control, while RB treatment was neither significantly different from Ang II alone nor control. Enzymes which convert O2- to hydrogen peroxide (H₂O₂), SOD1, SOD2 and NQO1, were all significantly increased in RB-supplemented animals compared to Ang II treatment alone. Finally, CAT, a peroxidase which neutralizes H₂O₂ to H₂O, was significantly increased in RB-supplemented animals compared to Ang II alone.

Conclusions: An RB-supplemented diet favorably improved the protein expression of redox enzymes, suggesting significantly increased antioxidant activity in the lung. Future work should assess whether RB supplementation could improve lung function in animal models of lung disease.

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.