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Ozone-Induced Vascular Contractility and Pulmonary Injury Are Differently Impacted by Coconut, Fish and Olive Oil-Rich diets
Citation:
Snow, S., W. Cheng, A. Henriquez, M. Hodge, M. Schladweiler, J. Richards, H. Tong, K. Gowdy, AND U. Kodavanti. Ozone-Induced Vascular Contractility and Pulmonary Injury Are Differently Impacted by Coconut, Fish and Olive Oil-Rich diets. Experimental Biology, Chicago, IL, April 22 - 26, 2017.
Impact/Purpose:
The omega-3 polyunsaturated fatty acids present in fish oil supplements are proposed to offer cardioprotective benefits, but it is not established if these supplements can protect against the adverse health effects induced by exposure to air pollution. Our data indicate that while fish oil offered protection from ozone-induced aortic vasoconstriction and vascular albumin leakage in the lung, it increased pulmonary injury/inflammation and impaired lipid transport mechanisms resulting in foamy macrophage accumulation. These data demonstrate the need to be cognizant of potential off-target pulmonary effects that might offset the overall benefit of this vasoprotective dietary supplement.
Description:
The omega-3 polyunsaturated fatty acids present in fish oil supplements are proposed to offer cardioprotective benefits, but it is not established if these supplements can protect against the adverse health effects induced by exposure to air pollution. Ozone, an ubiquitous air pollutant and a component of smog, is associated with premature cardiovascular mortality. We hypothesized that fish oil dietary supplementation would attenuate ozone-induced vascular and pulmonary impairments. Male Wistar Kyoto (WKY) rats were fed either a normal diet or a diet enriched with fish oil (6% by weight) starting at 4 weeks of age. Eight weeks following the initial start of the diet, animals were exposed to filtered air or 0.8 ppm ozone, 4h/day for 2 days. Aortic segments were isolated for myograph assessment of vascular reactivity in response to pharmacological intervention. The phenylephrine-induced vasoconstriction that was increased following ozone exposure in the animals fed the normal diet was completely abolished in the animals fed the fish oil diet, demonstrating vascular protection against this ozone-induced effect. Contrary to the vasoprotective response, the fish oil supplementation exacerbated pulmonary injury and inflammation. The fish oil diet increased baseline levels of bronchoalveolar lavage fluid (BALF) total protein, inflammatory cells (macrophages, neutrophils, and eosinophils), inflammatory cytokines (TNF-α and KC/GRO), as well as, lactate dehydrogenase, gamma-glutamyl transpeptidase, and n-acetyl glucosaminidase (NAG) activity, but did not increase albumin leakage. Fish oil further exacerbated increases in NAG activity, TNF-α and IL-6 proteins following ozone exposure, but attenuated the ozone-induced albumin leakage, neutrophilic and eosinophilic inflammation. Furthermore, fish oil supplementation regardless of exposure led to enlarged, foamy macrophages in the BALF that coincided with decreased mRNA expression of cholesterol transporters (ABCA1 and ABCG1), cholesterol receptors (SR-B1 and LDLR), and nuclear receptors (LXR-α and PPAR-α) in the lung. Collectively, these data indicate that while fish oil offered protection from ozone-induced aortic vasoconstriction and vascular albumin leakage in the lung, it increased pulmonary injury/inflammation and impaired lipid transport mechanisms resulting in foamy macrophage accumulation. These data demonstrate the need to be cognizant of potential off-target pulmonary effects that might offset the overall benefit of this vasoprotective dietary supplement. (Does not reflect the US EPA policy).