title: Acute improvement of endothelial functions after oral ingestion of isohumulones, bitter components of beer.
abstract: Isohumulones, principal components of the bitter taste of beers, have antioxidant capacity. We studied i) the effects of oral ingestion of isomerized hop extract (IHE) on the endothelial functions in smokers as well as non-smokers and ii) the effects of IHE on cultured endothelial cells in high oxidative stress state. Twelve cigarette smokers and eleven non-smokers ingested IHE and placebo in a randomized crossover design. Flow-mediated vasodilatation (FMD) was measured using ultrasonography. We also studied the effects of isohumulones on i) the cell viability under hypoxia and ii) the levels of angiotensin II (AT-II)-induced reactive oxygen species (ROS) in the cultured human aortic endothelial cells (HAECs). At baseline, the FMDs of the smokers were significantly lower than those of the non-smokers. The FMDs increased significantly after 30 min and 120 min of IHE ingestion in both the smokers and the non-smokers. IHE protected the HAECs from hypoxia-induced cell death as assessed by cell viability. IHE also reduced the AT-II-induced intracellular ROS level. Oral ingestion of IHE appears to exert acute beneficial effects on the endothelial functions in both the smokers and non-smokers, and the in vitro experiments using HAECs suggested that the effect be through reducing intracellular oxidative stress.
authors.affiliation: Department of Cardiology, Kasaoka City Hospital, Japan; Department of Hematology, Oncology, and Respiratory Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan. Electronic address: tomita-j@kasaokacityhsp.jp.
authors.forename: Junko
authors.initials: J
authors.lastname: Tomita
authors.affiliation: Department of Medical Engineering, Kawasaki University of Medical Welfare, Japan.
authors.forename: Seiichi
authors.initials: S
authors.lastname: Mochizuki
authors.affiliation: Department of Health Care Medicine, Kawasaki Medical School, Japan.
authors.forename: Sohachi
authors.initials: S
authors.lastname: Fujimoto
authors.affiliation: Department of Nephrology, Kawasaki Medical School, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kashihara
authors.affiliation: Department of Cardiology, Wakayama Medical University, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Akasaka
authors.affiliation: Department of Hematology, Oncology, and Respiratory Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan; Department of Medicine, Iwakuni Medical Center, Japan.
authors.forename: Mitsune
authors.initials: M
authors.lastname: Tanimoto
authors.affiliation: Department of Cardiology, Sakakibara Heart Institute of Okayama, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Yoshida
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000434:Alcoholic Beverages; D001515:Beer; D002478:Cells, Cultured; D018592:Cross-Over Studies; D003517:Cyclopentanes / Q000008:administration & dosage*; D004311:Double-Blind Method; D004435:Eating / Q000502:physiology; D042783:Endothelial Cells / Q000187:drug effects* / Q000502:physiology*; D006801:Humans; D027582:Humulus / Q000737:chemistry*; D008297:Male; D009569:Nitric Oxide / Q000097:blood; D010936:Plant Extracts / Q000008:administration & dosage; D012907:Smoking / Q000188:drug therapy / Q000378:metabolism*
chemical_list: D003517:Cyclopentanes; D010936:Plant Extracts; D009569:Nitric Oxide; C081209:isohumulone
keywords: Beer hop; Cigarette smoker; Endothelial cell; Endothelial dysfunction; Isohumulones; Oxidative stress