tetrahydroisohumulone (TRA), hexahydroisohumulone (HEX) and rho-isohumulone [3,4]. In vivo and in vitro studies in rats and mice suggest that isohumulones and reduced isohumulones had anti-cancer activity in Fischer 344 rats, anti-inflammatory activity in C57BL/6 mice, KK-A y mice and murine macrophage cell line RAW 264.7, and enhancement of glucose and lipid metabolism in C57BL/6 mice and Wistar rats [5][6][7][8][9][10]. Humulone at a dose of 50 μmol/mL reduced phorbol ester-induced cyclooxygenase-2 (COX-2, prostaglandin-H-synthase EC 1.14.99.1), an inflammatory mediator in ICR mouse skin [11]. In vitro exposure to Rho isohumolone (20 µg/mL) suppresses the level of COX-2 protein in RAW 264.7 cells [12]. In humans rho isohumolone at 1000 mg/day reduced the clinical symptoms of patients with knee osteoarthritis in a 6-week trial [12]. Hop extract (18.