GPT and primary biliary cholangitis: Furthermore, pretreatment with OA or ursodeoxycholic acid (UDCA), the only approved drug for treatment of PBC by Food and Drug Administration (FDA), in BDL mice lowered the level of alanine aminotransferase (ALT) by 59% and 41%, aspartate transaminase (AST) by 33% and 28%, alkaline phosphatase (ALP) by 44% and 39%, respectively.