Butein inhibits ethanol-induced activation of liver stellate cells through TGF-β, NFκB, p38, and JNK signaling pathways and inhibition of oxidative stress.
BACKGROUND
Butein has been reported to prevent and partly reverse liver fibrosis in vivo; however, the mechanisms of its action are poorly understood. We, therefore, aimed to determine the antifibrotic potential of butein.


METHODS
We assessed the influence of the incubation of hepatic stellate cells (HSCs) and hepatoma cells (HepG2) with butein on sensitivity to ethanol- or acetaldehyde-induced toxicity; the production of reactive oxygen species (ROS); the expression of markers of HSC activation, including smooth muscle α-actin (α-SMA) and procollagen I; and the production of transforming growth factor-β1 (TGF-β1), metalloproteinases-2 and -13 (MMP-2and MMP-13), and tissue inhibitors of metalloproteinases (TIMPs). The influence of butein on intracellular signals in HSCs; i.e., nuclear factor-κB (NFκB), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38 MAPK) induced by ethanol was estimated.


RESULTS
Butein protected HSCs and HepG2 cells against ethanol toxicity by the inhibition of ethanol- or acetaldehyde-induced production of ROS when cells were incubated separately or in co-cultures; butein also inhibited HSC activation measured as the production of α-SMA and procollagen I. As well, butein downregulated ethanol- or acetaldehyde-induced HSC migration and the production of TGF-β, TIMP-1, and TIMP-2; decreased the activity of MMP-2; and increased the activity of MMP-13. In ethanol-induced HSCs, butein inhibited the activation of the p38 MAPK and JNK transduction pathways as well as significantly inhibiting the phosphorylation of NF κB inhibitor (IκB) and Smad3.


CONCLUSIONS
The results indicated that butein inhibited ethanol- and acetaldehyde-induced activation of HSCs at different levels, acting as an antioxidant and inhibitor of ethanol-induced MAPK, TGF-β, and NFκB/IκB transduction signaling; this result makes butein a promising agent for antifibrotic therapies.
Department of Virology and Immunology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland. szustera@hektor.umcs.lublin.pl
Agnieszka
A
Szuster-Ciesielska
Magdalena
M
Mizerska-Dudka
Jadwiga
J
Daniluk
Martyna
M
Kandefer-Szerszeń
D000079:Acetaldehyde / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000199:Actins / Q000096:biosynthesis; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D047188:Chalcones / Q000494:pharmacology*; D018920:Coculture Techniques; D024042:Collagen Type I / Q000096:biosynthesis; D004353:Drug Evaluation, Preclinical / Q000379:methods; D000431:Ethanol / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D056945:Hep G2 Cells; D055166:Hepatic Stellate Cells / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D048670:MAP Kinase Kinase 4 / Q000502:physiology; D016328:NF-kappa B / Q000502:physiology; D018384:Oxidative Stress / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D016212:Transforming Growth Factor beta / Q000502:physiology; D048051:p38 Mitogen-Activated Protein Kinases / Q000502:physiology
D000079:Acetaldehyde; D000199:Actins; D000975:Antioxidants; D047188:Chalcones; D024042:Collagen Type I; D000431:Ethanol; D048670:MAP Kinase Kinase 4; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D016212:Transforming Growth Factor beta; D048051:p38 Mitogen-Activated Protein Kinases; C498862:Acta2 protein, rat; C040918:butein