We have previously reported the effects of Kaempferia parviflora (KP), including anti-obesity, preventing various metabolic diseases, and regulating differentiation of white adipose cells. In this study we used Tsumura, Suzuki, Obese Diabetes (TSOD) mice--an animal model of spontaneous obese type II diabetes--and primary brown preadipocytes to examine the effects of the ethyl acetate extract of KP (KPE) on brown adipose tissue, which is one of the energy expenditure organs. TSOD mice were fed with MF mixed with either KPE 0.3 or 1% for 8 weeks. Computed tomography images showed that whitening of brown adipocytes was suppressed in the interscapular tissue of the KPE group. We also examined mRNA expression of uncoupling protein 1 (UCP-1) and β3-adrenalin receptor (β3AR) in brown adipose tissue. As a result, mRNA expression of UCP-1 significantly increased in the KPE 1% treatment group, indicating that KPE activated brown adipose tissue. We then evaluated the direct effects of KPE on brown adipocytes using primary brown preadipocytes isolated from interscapular brown adipocytes in ICR mice. Triacylglycerol (TG) accumulation in primary brown preadipocytes was increased by KPE in a dose-dependent manner. Each mRNA expression of peroxisome proliferator-activated receptor γ (PPARγ), UCP-1, and β3AR exhibited an upward trend compared with the control group. Moreover, some polymethoxyflavonoids (PMFs), the main compound in KP, also increased TG accumulation. This study therefore showed that KPE enhanced the thermogenesis effect of brown adipocytes as well as promoted the differentiation of brown adipocyte cells.
Keywords: Brown adipose tissue; Kaempferia parviflora; Polymethoxyflavonoids; TSOD mice; UCP-1.