8-Prenylnaringenin suppresses obesity in high-fat diet-fed C57BL/6J mice via adiponectin secretion.

8-Prenylnaringenin (8-PN) is a prenylflavonoid found in hops (Humulus lupulus L.). It has several beneficial functions, which include the inhibition of bone loss and muscle atrophy. 8-PN is a metabolite of xanthohumol, which can prevent obesity in mice; however, the effect of 8-PN on obesity is still unknown. In the present study, we found that 8-PN prevented obesity in high-fat diet-fed mice. When C57BL6/J male mice were fed 8-PN at 0.0005% or 0.005% with a high-fat diet for 8 weeks, body weight gain, fat accumulation in adipose tissue, and fatty liver induced by the high-fat diet were prevented. In mice fed a high-fat diet and 8-PN, adenosine monophosphate-activated protein kinase (AMPK) was activated in visceral adipose tissue, which was accompanied by decreased expression of a fatty acid synthesis-related factor and increased expression of a mitochondrial biosynthesis-related factor downstream of AMPK. AMPK appeared to be activated by adiponectin secretion, which was associated with increased expression of adipocyte differentiation markers in mice fed a high-fat diet and 8-PN. For the first time, this study shows that 8-PN can prevent obesity in mice and that it is effective at low concentrations that humans could consume in their daily diet.