Intake of Herring Oils Resulted in Lower Pulmonary Concentration of Angiotensin-Converting Enzyme 2 without affecting Blood Pressure in Obese Rats.

BACKGROUND

Angiotensin-converting enzyme 2 (ACE2) is a receptor for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and is involved in blood pressure regulation and inflammation through the renin-angiotensin system. Fish intake is associated with a lower risk of severe coronavirus disease 2019, but the effect of fish oil intake on pulmonary ACE2 has not been investigated.

OBJECTIVES

Primarily, to investigate the effect of consuming fish oils containing cetoleic acid (CA, 22:1n-11), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) on the pulmonary concentration of ACE2 in rats. Secondary outcomes include inflammatory markers in the lungs and blood pressure.

METHODS

Thirty male obese Zucker fa/fa rats aged 7 wk were fed regular diets containing herring oil (HERO), a CA concentrate (CECO), or soybean oil as the sole lipid source (control diet) for 5 wk. The HERO diet contained 0.70 wt% CA and 0.35 wt% EPA + DHA, and the CECO diet contained 1.40 wt% CA and 0.24 wt% EPA + DHA. Blood and tissues were collected at the endpoint, and blood pressure was measured at baseline and after 33 d. Data were analyzed using 1-way analysis of variance followed by Fisher's least significant difference test when appropriate.

RESULTS

Compared with controls, the HERO and CECO groups had lower pulmonary protein concentrations of ACE2 (32% and 24%, respectively), tumor necrosis factor-α (31% and 28%, respectively), and monocyte chemotactic protein 1 (34% and 17%, respectively), all comparisons P < 0.05, with no effect on blood pressure (P > 0.05).

CONCLUSIONS

The lower pulmonary ACE2 concentration indicates that herring oils could reduce cell entry of SARS-CoV-2 without a detrimental increase in blood pressure. Herring oils also reduced protein concentrations of inflammatory markers in the lungs.