Abstract: AimTo observe the protective effects of tanshinones (tanshinone IIA, tanshinone I, cryptotanshinone and dihydrotanshinone) against liver injury in mice loaded with restraint stress. Methods The liver injury model was established under 12 h restraint stress in mice 5 days after tanshinones treatment. The hepatoprotective effects were evaluated by assessing alanine aminotransferase (ALT) levels in plasma. The contents of vitamin C, GSH and malondialdehyde (MDA) in liver were performed by HPLC and TBARS methods, respectively. Oxygen radical absorbance capacity (ORAC) assay was used to measure the antioxidant capacity. ResultsTanshinones decreased ALT and MDA levels, and increased ORAC, vitamin C and GSH levels in liver tissues as compared with restraint stress control. Tanshinones also significantly inhibited oxidation In vitro. Among four tanshinones, dihydrotanshinone was more effective than others both in vivo and In vitro test. ConclusionTanshinones possesses potent antioxidant activity In vitro and in vivo, and protected against liver injury induced by restraint stress. The active mechanisms may be related to their antioxidant capability.