国家自然科学基金303004149;国家中医药管理局02-03ZP52;重庆医科大学XBYB2007104,XBYB2007108资助项目.This work was supported by grants from The National Natural Science Foundation of China30300449;State Administration of Traditional Chinese Medicine02-03ZP52;Chongqing Medical UniversityXBYB2007104, XBYB2007108