The present invention relates to a compound of Antrodia camphorata used to treat autoimmune diseases, in particular to an extract, 4-hydroxy-2,3-dimethoxy-6-methyl-5(3,7,11-trimethyl-dodeca-2,6,10-trienyl)-cyclohex-2-enone, isolated from Antrodia camphorata, and its use in alleviating symptoms of autoimmune diseases such as systemic lupus erythematosus (SLE). The cyclohexenone compound according to the present invention helps to decrease proteinuria levels and antinuclear antibody titers in SLE mammals in order to alleviate kidney inflammation and disease, as well as the self-damage caused by antinuclear antibodies. The purpose for prevention and treatment of autoimmune diseases and kidney diseases by the natural, side-effect free substance can then be accomplished.本發明係關於一種用於治療自體免疫疾病之牛樟芝環己烯酮化合物，尤其是關於一種由牛樟芝萃取物中分離出之4－羥基－2,3－二甲氧基－6－甲基－5(3,7,11－三甲基－2,6,10－十二碳三烯)－2－環己烯酮(4－hydroxy－2,3－dimethoxy－6－methy－5[3,7,11－trimethyl－dodeca－2,6,10－trienyl]－cyclohex－2－enone)並可有效減緩系統性紅斑性狼瘡等自體免疫疾病所致病症。本發明中，牛樟芝環己烯酮化合物係有助於降低罹患系統性紅斑性狼瘡哺乳動物之尿蛋白含量以及血液中抗核抗體之濃度，藉以減緩腎臟發炎與病變，並降低抗核抗體對自體組織的傷害，而達到以天然無副作用物質治療系統性紅斑性狼瘡等自體免疫性疾病以及腎臟相關疾病之效果。
