The present invention provides methods of administering a Dendrobium polyphenol in an amount effective to lower blood sugar, treat hepatic disease, obesity or diabetes. Exemplary hepatic disease includes fibrosis, fatty liver and hepatitis. Moreover, the Dendrobium polyphenol is extracted from the plants of the genus Dendrobium.本發明所揭之石斛多酚係為萃取自藥用植物中之活性成份，具有對抗如肝臟纖維化、肝臟脂肪堆積、肝臟發炎等肝臟病變、調控血糖以及降低體重之功效，可用以製造作為治療肝臟疾病或是糖尿病之醫藥組合物，或是作為一保健食品而具有保肝或是調控血糖之功效。
