Protective effects of Kurozu and Kurozu Moromimatsu on dextran sulfate sodium-induced experimental colitis.

Background: Kurozu, a traditional Japanese black vinegar made from unpolished rice, and Kurozu Moromimatsu (Kurozu-M), its sediment, are both consumed in Japan as health foods or supplements. However, it is not known whether they have anti-colitis activity.

Aims: We examined the protective effects of Kurozu and Kurozu-M in an animal model of dextran sulfate sodium (DSS)-induced colitis.

Methods: DSS-induced colitis was induced in C57 black 6 mice by orally administering 3.5% DSS solution for 12 days. The control group received basal CE-2 diet (n = 10), the Kurozu group received CE-2 containing Kurozu (n = 10), the Kurozu-M group received CE-2 containing Kurozu-M (n = 10), and the acetic acid group received CE-2 containing acetic acid (n = 10), starting a week before DSS administration. Changes of body weight and bloody stool frequency were monitored. At 12 days after DSS administration, mice were killed for pathological examination and measurement of nitrotyrosine levels in rectal tissues.

Results: Kurozu significantly inhibited body weight loss during 6-12 days after DSS administration and reduced bloody stool frequency during 2-12 days, and also significantly decreased nitrotyrosine levels at 12 days, compared to the control group. Kurozu-M significantly inhibited body weight loss during 6-8 days after DSS administration and reduced bloody stool frequency during 2-12 days, but tissue nitrotyrosine level was not significantly different from the control. Acetic acid had no ameliorating effect on DSS-induced colitis compared to the control group.

Conclusions: Kurozu and Kurozu-M have protective effects against DSS-induced colitis. Kurozu has anti-oxidative and anti-nitration activity.