熊果酸和齊墩果酸的抗氧化作用能對抗各種原因引起的氧化應(yīng)激所致的肝組織脂質(zhì)過氧化反應(yīng)、炎性損傷、脂肪變和纖維化。熊果酸和齊墩果酸通過阻斷兩面神激酶2-信號傳導(dǎo)及轉(zhuǎn)錄激活因子3（JAK2-STAT₃）信號轉(zhuǎn)導(dǎo)，抑制還原型煙酰胺腺嘌呤二核苷酸磷酸氧化酶（NOX）活化，阻止靜息態(tài)肝星狀細胞活化、增殖，促進活化態(tài)肝星狀細胞凋亡，從而減少膠原生成、增加細胞外基質(zhì)降解，產(chǎn)生防治肝纖維化的作用。熊果酸和齊墩果酸誘導(dǎo)肝臟去毒酶和外排轉(zhuǎn)運體表達，降低膽汁淤積動物血清膽汁酸、膽紅素水平和肝臟膽汁酸水平，減輕膽汁淤積性肝損傷和纖維化；還可通過降血脂作用抑制肝外脂質(zhì)在肝臟沉積、抑制肝臟脂質(zhì)生物合成和促進脂質(zhì)代謝，阻滯肝脂肪變的發(fā)生和發(fā)展。

Anti-oxidation of ursolic acid and oleanolic acid antagonizes oxidative stress-induced lipid peroxidation, inflammatory injury, steatosis, and fibrosis in liver tissue. Ursolic acid and oleanolic acid could block static state hepatic stellate cells activation and proliferation, and promote active state hepatic stellate cells apoptosis, thus decrease expression of collagen, and increase decomposition of extracellular matrix, to produce the effect in prevention and treatment of hepatic fibrosis by obstruction of JAK2-STAT₃ signal transduction to inhibit NOX activation. Ursolic acid and oleanolic acid induce expression of detoxification enzymes and efflux transporters to reduce serum levels of bile acids and bilirubin, and liver levels of bile acids in cholestatic animal, thus ameliorating cholestatic liver injury and fibrosis. Ursolic acid and oleanolic acid inhibit occurrence and development of hepatic steatosis via decreasing hyperlipidemia to inhibit lipid out of liver accumulating to liver, inhibiting hepatic lipid synthesis, and improving lipid metabolism.