Monosodium glutamate (MSG): a villain and promoter of liver inflammation and dysplasia.
Chronic inflammation is a common theme in a variety of disease pathways, including autoimmune diseases. The pathways of chronic inflammation are well illustrated by nonalcoholic steatohepatitis (NASH), which is of a serious concern due to its increasing prevalence in the westernized world and its direct correlation with lifestyle factors, particularly diet. Importantly, NASH may ultimately lead to the development of hepatocellular carcinoma. We previously reported that injection of monosodium glutamate (MSG) in ICR mice leads to the development of significant inflammation, central obesity, and type 2 diabetes. To directly address the long-term consequences of MSG on inflammation, we have performed serial analysis of MSG-injected mice and focused in particular on liver pathology. By 6 and 12 months of age, all MSG-treated mice developed NAFLD and NASH-like histology, respectively. In particular, the murine steatohepatitis at 12 months was virtually undistinguishable from human NASH. Further, dysplastic nodular lesions were detected in some cases within the fibrotic liver parenchyma. We submit that MSG treatment of mice induces obesity and diabetes with steatosis and steatohepatitis resembling human NAFLD and NASH with pre-neoplastic lesions. These results take on considerable significance in light of the widespread usage of dietary MSG and we suggest that MSG should have its safety profile re-examined and be potentially withdrawn from the food chain.
Nakanishi
Yuko
Y
Department of Diagnostic Pathology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
Tsuneyama
Koichi
K
Fujimoto
Makoto
M
Salunga
Thucydides L
TL
Nomoto
Kazuhiro
K
An
Jun-Ling
JL
Takano
Yasuo
Y
Iizuka
Seiichi
S
Nagata
Mitsunobu
M
Suzuki
Wataru
W
Shimada
Tsutomu
T
Aburada
Masaki
M
Nakano
Masayuki
M
Selmi
Carlo
C
Gershwin
M Eric
ME
D000818:Animals; D056486:Chemical and Drug Induced Liver Injury / Q000209:etiology / Q000473:pathology*; D003924:Diabetes Mellitus, Type 2 / Q000139:chemically induced / Q000276:immunology / Q000473:pathology*; D005234:Fatty Liver / Q000139:chemically induced / Q000276:immunology / Q000473:pathology*; D006801:Humans; D008099:Liver / Q000473:pathology*; D008103:Liver Cirrhosis / Q000473:pathology; D051379:Mice; D009765:Obesity / Q000139:chemically induced / Q000276:immunology; D012970:Sodium Glutamate / Q000008:administration & dosage / Q000633:toxicity*
D012970:Sodium Glutamate