Objective: To study the protective effects of Curcuma zanthorrhiza rhizome on liver injury induced by concanavalin A(Con A) in mice

and investigate its possible mechanism. Method: SPF mice were randomly divided into normal group

model group

biphenyl group

C. zanthorrhiza rhizome high dose group

middle dose group and low dose group. All the mice except those in normal group received Con A (30 mg·kg-1) by injection via tail vein to induce mice liver injury. The drugs were given for 7 days by gavage administration

and the mice in normal group received the equal volume of normal saline. After fasting (but water was given) for 8 h

their body weight was measured; blood was taken from eyeball

and the mice were killed by taking off the cervical vertebrae. Then their liver index

spleen index

contents of alanine aminotransferase (ALT)

aspartate amino transferase (AST)

and lactate dehydrogenase (LDH) in serum and total superoxide dismutase (T-SOD)

malondialdehyde (MDA)

nitric oxide (NO) in liver homogenates were measured. Hepatic tissue was observed by hematoxylin-eosin staining. Furthermore

real-time fluorescence quantitative PCR (Real-time PCR) and Western blot assay were used to detect mRNA and protein expression levels of liver tramsforming gravth factor-β1(TGF-β1)

Smad3 and Smad7. Result: As compared with the normal group

the liver index

spleen index

levels of ALT

AST and LDH in serum as well as MDA and NO levels in liver homogenates were significantly increased in model group; T-SOD level in liver homogenates was significantly reduced; mRNA and protein expression levels of liver TGF-β1

Smad3 were significantly increased

while mRNA and protein expression levels of Smad3 were significantly reduced (P<0.01)

with more obvious liver lesions in model group. As compared with the model group

both C. zanthorrhiza rhizome and biphenyl significantly reduced the liver index and spleen index; decreased the levels of ALT

AST

LDH in serum and MDA

NO levels in liver homogenates; and significantly increased T-SOD level in liver homogenates. The liver lesions were significantly relieved in C. zanthorrhiza rhizome high dose group

mRNA and protein expression levels of liver TGF-β1

Smad3 were reduced

while mRNA and protein expression levels of Smad3 were increased (P<0.05

P<0.01). Conclusion: Curcuma zanthorrhiza rhizome had significant protective effect for the liver injury induced by Con A

and its mechanism to block the progression of liver injury may be associated with multi-site affecting TGF-β1/Smad pathways in liver tissues.