Effects of probiotics on methionine choline deficient diet-induced steatohepatitis in rats.
OBJECTIVE
Intestinal bacteria induce endogenous signals that play a pathogenic role in hepatic insulin resistance and non-alcoholic fatty liver disease. Probiotics could modulate the gut flora and could influence the gut-liver axis. We aimed to investigate the preventive effect of two probiotic mixtures on the methionine choline-deficient diet-induced non-alcoholic steatohepatitis model in rats.


METHODS
Two studies, short-term (2 weeks) and long-term (6 weeks), were carried out using 60 male Wistar rats. The 2-week study included six groups. Rats were fed with methionine choline-deficient diet or pair-fed control diet and were given a placebo or one of two probiotic mixtures (Pro-1 and Pro-2) by orogastric gavage. In the 6-week study, rats were allocated into four groups and were fed with methionine choline-deficient diet or pair-fed control diet and given a placebo or Pro-2. At the end of the 2- and 6-week periods, blood samples were obtained, the animals were sacrificed, and liver tissues were removed. Serum alanine aminotransferase activity was determined; histologic and immunohistochemical analysis was performed for steatosis, inflammation, protein expression of tumor necrosis factor-α, and apoptosis markers.


RESULTS
In both studies, methionine choline-deficient diet caused an elevation of serum alanine aminotransferase activity, which was slightly reduced by Pro-1 and Pro-2. In the 2- and 6-week studies, feeding with methionine choline-deficient diet resulted in steatosis and inflammation, but not fibrosis, in all rats. In the 2-week study, in rats fed with methionine choline-deficient diet and given Pro-1, steatosis and inflammation were present in 2 of 6 rats. In rats fed with methionine choline-deficient diet and given Pro-2, steatosis was detected in 3 of 6 rats, while inflammation was present in 2 of 6 rats. In the 6-week study, in rats fed with methionine choline-deficient diet and given Pro-2, steatosis and inflammation were present in 3 of 6 rat livers. In both the 2- and 6-week studies, methionine choline-deficient diet resulted in tumor necrosis factor-α, proapoptotic Bax, caspase 3, caspase 8, and anti-apoptotic Bcl-2 expression in all rat livers. Pro-1 and Pro-2 treatment influenced protein expression involved in apoptosis and tumor necrosis factor-α in varying degrees.


CONCLUSIONS
Pro-1 and Pro-2 decrease methionine choline-deficient diet-induced steatohepatitis in rats. The preventive effect of probiotics may be due, in part, to modulation of apoptosis and their anti-inflammatory activity.
Süleyman Demirel University Faculty of Medicine, Department of Pathology, Isparta, Turkey. nerminkarahan@hotmail.com
Nermin
N
Karahan
Mehmet
M
Işler
Ahmet
A
Koyu
Aynur G
AG
Karahan
Gülden
G
Başyığıt Kiliç
Ibrahim Metin
IM
Cırış
Recep
R
Sütçü
Ibrahim
I
Onaran
Hakan
H
Cam
Muharrem
M
Keskın
D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D053148:Caspase 3 / Q000378:metabolism; D053181:Caspase 8 / Q000378:metabolism; D002796:Choline Deficiency; D004032:Diet; D004195:Disease Models, Animal; D005234:Fatty Liver / Q000139:chemically induced / Q000473:pathology* / Q000628:therapy*; D007150:Immunohistochemistry; D007249:Inflammation / Q000473:pathology; D008099:Liver / Q000378:metabolism / Q000473:pathology*; D008297:Male; D019936:Probiotics / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000378:metabolism
C494828:Bax protein, rat; D014409:Tumor Necrosis Factor-alpha; D051028:bcl-2-Associated X Protein; D000410:Alanine Transaminase; D053148:Caspase 3; D053181:Caspase 8