The Experimental Study Of Periplaneta Americana Extract On Liver Injury

Objective:To investigate the protective effects of two kinds extracts of Periplaneta Americana （PA）and their mechanisms on liver injury, based on the traditional cure idea of "activating blood circulation to dissipate blood stasis, detoxifying to eliminate malnutrition" and our prior study that extracts of live PA showed great protection against liver injury. In this paper, animal models of CCl₄-induced acute liver injury in mice were established to screen the effective extracts of PA, models of acute liver injury induced by acetaminophen and alcohol were established in mice to verify effects of the very extracts, while chronic liver injury model induced by CCl₄ in rats was established to explore the mechanisms of the extracts on liver injury.Methods:1. Acute liver injury animal models induced by CCl₄ in mice was established, intragastric administration of PA extracts （extract of Periplaneta americana by cooling extraction on live insects using cold 75% ethanol（EoPa）, water extract of Periplaneta americana dregs left by cooling extraction on live insects using cold 75% ethanol （WEoPa）） were given to animals for 10 days, Viscera indices and anti-oxygen related indicators in serum and liver tissue were detected to evaluate the protective effects of different extracts of PA.2. Acute liver injury animal models induced by acetaminophen and alcohol in mice were established respectively, effects of different extracts were further verified by investigating related indicators in serum and histo-pathology of liver was examined to evaluate the effect of extracts against liver injury in mice.3. The model of chronic liver injury induced by CCl₄ in rats was established, Intragastric administration of EoPa and WEoPa were given to rats for 7 weeks, respectively. The activities or contents of alanine aminotransferase （ALT）, Glutamic oxalacetic transaminase （AST）, alkline phosphatase （AKP）, total protein （TP）, albumin（ALB）, hydroxyproline（Hyp） and indices related to liver fibrosis such as hyaluronidase（HA）, laminin （LN）, pro collagen Ⅲ（PCⅢ） and collagen-type IV （ColIV） in serum were determined, the activities of Superoxide Dismutase （SOD）, Malondialdehyde （MDA）,glutathione peroxidasein （GSH-Px） and total antioxidant capacityin（T-AOC） in liver were observed, Viscera indices and the histo-pathology of liver was examined to evaluate the effect of different extracts against chronic liver injury in rats.Results:1. The activities of ALT and AST in serum of liver injury mice induced by CCl₄ were significantly reduced in animals administrated EoPa at the dosage of 65.07 and 130.14 mg/kg （P<0.05 or P<0.01） and animals administrated WEoPa at the dosage of 49.13mg/kg, the later can significantly reduce the content of MDA in liver homogenate （P<0.05）.2. EoPa at the dosage of 86.76 mg/kg can obviously reduce ALT activity in serum of mice induced by acetaminophen （P<0.05）, while WEoPa at the dosage of 49.13mg/kg had a decreasing trend on activities of AST and ALT in serum and significantly decreased the spleen index of model mice （P<0.05）.3. EoPa at the dosage of 43.38mg/kg,65.07mg/kg can significantly decreased the liver index of mice induced by alcohol （P<0.01）, which at the dosage of 43.38mg/kg,65.07mg/kg and 86.76mg/kg significantly decreased the spleen index and AST activity in serum （P<0.01）, and which at the dosage of 65.07mg/kg,86.76mg/kg significantly decreased ALT activity in serum （P<0.01）. WEoPa at the dosage of 49.13mg/kg and 65.51 mg/kg significantly reduced the activities of AST and ALT in serum （P<0.01） and inhibited the abnormal increase of the content of MDA in liver tissue （P<0.05）.4. EoPa at the dosage of 60.35mg/kg and 100.35mg/kg significantly increased the thymus index of chronic liver injury rats model induced by CCl₄ （P<0.01）, which significantly decreased contents of LN and COLIV in serum （P<0.01）. WEoPa at the dosage of 49.13mg/kg and 75.78mg/kg significantly increased the thymus index of rats, which at the dosage of 75.78mg/kg significantly decreased the activities of AST, ALT and Hyp, AKP （P<0.05）, and increased the ALB content （P<0.05） in serum, which also can significantly decrease contents of HA, LN, COIIV and PC Ⅲ in serum （P<0.01）and MDA content in liver homogenate（P<0.05）and significantly increased T-AOC content and GSH-PX activity in liver homogenate （P<0.05）Conclusions:EoPa and WEoPa have a good protection effects on both acute and chronic liver injury animal models, which maybe the main material basis of PA on liver injury, Improving the immune function, antioxidation, anti-fibrosis and promoting the repair process of liver may be parts of its mechanisms.