Inhaled turmerone can attenuate nicotine-induced degeneration of the aorta

Abstract

Nicotine in secondhand smoke can increase the risk of development of cardiovascular disease in passive smokers through degeneration of the aorta which is one of main pathologies of cardiovascular disease. We speculated that the adverse effect of nicotine can be attenuated by volatile active molecules. As the potential molecule having vasoprotective effect, we focused on turmerone which is major volatile compound in turmeric (Curcuma longa). Oral administration of turmerone reportedly shows biological activities such as anti-inflammation, anti-oxidation, and anti-depression effects. We previously reported that turmerone was detected in the blood and organs of mice that inhaled turmeric essential oil. In addition, high fat-induced weight gain was suppressed in the group of mice that inhaled turmeric essential oil, suggesting the existence of biological activity of inhaled turmerone. However, the effects of inhaled turmerone on the aorta remain unclear. The aim of this study is to investigate the effects of inhaled turmerone on nicotine-induced aortic degeneration. Nicotine-induced degradation of elastic fiber and increased matrix metalloproteinase (MMP)-2 was attenuated by inhalation of the turmeric essential oil. In the serum of mice that inhaled the turmeric essential oil, all turmerone species, α-turmerone, β-turmerone, and ar-turmerone, were detected. In ex vivo cultured aorta, ar-turmerone showed the strongest protective effects on nicotine-induced degeneration of the aorta compared to α-turmerone and β-turmerone. These data indicate that inhaled turmerone attenuate nicotine-induced aortic degeneration after incorporated into the body.