Abstract: 〔Abstract〕Objective: To study the effects of active extract of Periplaneta americana（PA-B）on liver fibrosis induced by carbon
tetrachloride in rats by gastric and intestinal administration. Methods: According to the body weight, male SD rats were randomly
divided into 8 groups, including the control group, the model group, enteric-soluble excipient group, gastric-soluble excipient group,
the positive drug group, the active pharmaceutical ingredients（APIs）group, enteric drug group and gastric drug group. Except for the
control group, the other groups were intraperitoneally injected with 40% carbon tetrachloride oil, the control group was injected with the
same dose of olive oil. After successful modeling, each group was given corresponding drugs. The liver tissues were stained by
hematoxylin-eosin（HE）and Masson, and the pathological changes were observed under the microscope. The microplate method was
used to determine alanine aminotransferase（ALT）and aspartate aminotransferase（AST）; the enzyme-linked immunosorbent assay
（ELISA）was applied to measure serum liver fibrosis indexes hyaluronic acid（HA）, laminin（LN）, procollagen type Ⅲ（PC-Ⅲ）and
collagen type Ⅳ（Col-Ⅳ）; the content of hydroxyproline（HYP）in liver tissue was measured by the alkaline hydrolysis method.
Results: Compared with the control group, the model group had more collagen fibers and more false lobules; compared with the model
group, the levels of various detection indexes in the positive drug group, the APIs group, enteric drug group and gastric drug group
decreased, and the differences were statistically significant（P < 0.05 or P < 0.01）. There was no statistical significance in each index
among positive drug group, APIs group, enteric drug group and gastric drug group（P＞0.05）. Conclusion: PA-B and related
preparations could effectively improve liver fibrosis in rats, but there was no significant difference in the therapeutic effect of PA-B on
liver fibrosis in rats by gastric and intestinal administration.

Key words: 〔Key words〕Periplaneta americana, liver fibrosis, carbon tetrachloride, administration route