Administration of CCl4 caused a significant increase in the number of cells recognized by antibodies against SMA. Emodin treatment significantly reduced the number of cells labeled with SMA antibodies, suggesting that emodin might suppress HSC activation in the rat model. The comparative Ct method of 2 Ct and IHC evaluation result showed that protein and mRNA levels of SMA in liver tissues from normal control rats were 8.88 1.26 and 1.01 0.19, respectively while those in the CCl4 group were 21.97 1.68 and 3.52 0.60, respectively. Treatment of rats with emodin during CCl4 exposure largely increased expression of SMA and resulted in protein and mRNA levels of 14.61 1.67 and 2.46 0.91, respectively . Emodin reduces the concentration of TGF 1 in serum and mRNA levels in liver tissues TGF 1 is the major profibrogenic factor during hepatic fibrogenesis. We examined the effect of emodin on the concentration of TGF 1 in serum and mRNA levels in liver tissues of the rat model by ELISA and real time PCR. As shown in Figure 3, compared with those in the normal group , the levels of TGF 1 in serum and mRNA levels of TGF 1 in liver tissues were dramatically increased in the CCl4 group .
The levels of TGF 1 in serum and mRNA levels of TGF 1 in liver tissues were significantly Masitinib reduced in the emodin group . Although these was still higher than those of the normal group, these data indicated that emodin significantly reduced the levels of TGF 1 in serum and mRNA levels in liver tissues in the rat model, which might result in the inhibition of HSC activation stimulated by CCl4. Emodin down regulates the protein and mRNA levels of Smad4 in liver tissues of the CCl4 rat model Because TGF 1 signals within the cell through Smad is involved in fibrosis, the effects of emodin on mRNA and protein levels of Smad4 in liver tissues were demonstrated by real time PCR , Western blotting , and IHC analyses . Experiments revealed that exposure of rats to CCl4 significantly increased mRNA and protein levels of Smad4 in liver tissues from 1.00 0.13, 0.54 0.04 and 5.78 1.05, respectively, in the normal group to 4.63 0.86, 13.44 0.64 and 23.95 3.23, respectively, in the CCl4 group.
In contrast, protein and mRNA levels of Smad4 in liver tissues from rats treated with emodin during CCl4 exposure were attenuated and were 2.94 0.74, 9.25 0.84 and 17.00 1.88, respectively. Treatment of rats with emodin during CCl4 exposure blunted the increase in protein and mRNA levels of Smad4 significantly. DISCUSSION In the present study, we confirmed that emodin protects the rat liver from CCl4 induced injury and fibrogenesis. The mechanism for this protective compound libraries for drug discovery effect may relate to the fact that emodin efficiently inhibits HSC activation in vivo. Hepatic fibrosis, which may lead to cirrhosis, is associated with most chronic liver diseases .