Immunomodulatory effects by oral contraceptives in normal and cholestatic female rats: role of cytokines.

Abstract

Oral contraceptives (OC) may cause intrahepatic cholestasis or increase a pre-established liver damage. OC effects on hepatic injury biochemical markers remain contradictory and the role of cytokines in those processes is fairly unknown. Two doses, simple or double, of the OC combination ethinylestradiol/norgestrel were administered during 14 or 28 days to normal and cholestatic female rats. Liver damage markers and the cytokines tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) were determined in plasma and liver. OC caused ambiguous results on cholestasis indicators, even more in cholestatic rats. Necrosis rose during cholestasis while OC lowered it in normal rats. Fibrosis was induced by cholestasis but OC double dose or intake time diminished that. Cholestasis depleted glycogen while OC did not alter it. Double dose or time of administration of OC significantly elevated the lipid peroxidation. Cholestasis modified plasma and liver cytokines but OC remarkably altered them in normal and cholestatic animals. TNF-α as well as IL-10 were increased in both tissues by OC, such rise was higher in normal rats. TGF-β was augmented by OC and more in cholestatic rats receiving double dose. Thus, OC modified most liver injury markers in normal rats although more pronouncedly in cholestatic ones, as well as increased hepatic oxidative stress. Liver fibrosis was decreased and corroborated by histological analysis even when TGF-β is elevated by OC. OC strongly immunomodulate cytokines that mediate liver damage or worsen a prior hepatopathy; those processes are influenced by dose, administration time and OC formulation.