This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Anatomy
Ursodeoxycholic acid is a 
Select and explain. 
A. Urinary Stone dissolving drug, B. Thrombolytic drug, C. Gallstone dissolving drug, D. Antifibrinolytic
C: Gallstone dissolving drug
Answer: C: Gallstone dissolving drug 
Explanation: Medical therapy of Gallstones Medical therapy of gallstones utilize bile acids : Chenodeoxycholic acid(CDCA) and Ursodeoxycholic acid(UDCA) Mechanism of Action : They inhibit HMG-CoA reductase, rate limiting enzyme for cholesterol synthesis, thus decreasing cholesterol saturation of bile They cause disruption of cholesterol from the stones by physicochemical means Ref: Sabiston 20th edition Pgno : 1494