근육세포에서 진귤과피 성분의 대사조절 기능

Abstract

Citrus sunki Hort. ex Tanaka is one of several Jeju-native citrus fruits, and its dried peel has been used as an essential ingredient in traditional medicine. The purpose of the study was to investigate the effect of various compounds rich in the peel of Citrus sunki on glucose and fat metabolism in L6 muscle cells. Synephrine, an alkaloid compound, and two polymethoxyflavones, tangeritin and nobiletin, were more rich in the extract of Citrus sunki peel than other compounds. Synephrine increased glucose consumption by L6 muscle cells. Synephrine also increased the translocation of glucose transport 4 (GLUT4) to the plasma membrane. Synephrine stimulated the phosphorylation of AMPK, but not of PKB/Akt. Although tangeritin and nobiletin stimulated phosphorylation of AMPK, they failed to increased glucose consumption by muscle cells. Free fatty acid (FFA, palmitate)-induced cytoplasmic fat accumulation was suppressed by synephrine and PMFs. Palmitate-induced suppression of AMPK phosphorylation was also reversed by the addition of synephrine or PMFs. These results suggest that synephrine and PMFs rich in the peel of Citrus sunki are potent functional compounds that can ameliorate abnormalities in glucose-and fat metabolism in muscle cells.