Table 1. Melatonin regulation of biliary functions.

Parameter	Mechanisms	References
Inhibition of biliary hyperplasia in BDL rats	Reduced expression CLOCK genes by downregulation of cAMP levels, and PKA phosphorylation by interaction with MT1	(56)
Modulation of biliary hyperplasia in normal and BDL rats	In vivo and in vitro overexpression of AANAT in cholangiocytes decreased biliary proliferation	(42)
Modulation of biliary hyperplasia in ANIT-fed rats	Anti-oxidant activity	(60,61)
Inhibition of cholangiocarcinoma growth	Decreased AANAT expression and melatonin secretion leads to enhanced cholangiocarcinoma growth	(54)

Abbreviations: AANAT, arylalkylamine N-acetyltransferase; ANIT, α-naphthylisothiocyanate; BDL, bile duct ligation.