Serum biochemistry assays
Blood samples were taken from the abdominal aorta of anesthetized animals, and the serum levels of alanine aminotransferase (ALT), aspartate amino transferase (AST), alkaline phosphatase (ALP), total bilirubin (TBIL), and direct bilirubin (DBIL)(Sichuan Maker Biotechnology Co. Ltd, Chengdu, China) were measured using a standard automatic biochemical analyzer (HITACHI 7020).