Ascorbic acid (AA) has been shown to exert beneficial effects, including mitigating oxidative stress and inhibiting inflammation. However, the preventative effect of vitamin C in chronic inflammatory diseases such as inflammatory bowel disease (IBD) remains unclear. In our study, we investigated the anti-inflammatory effects of AA and possible mechanism involved in inhibiting dextran sulfate sodium (DSS)-induced ulcerative colitis in mice. Male C57BL/6 mice were randomly divided tothree groups: control group, DSS group, and DSS plus ascorbic acid treated group. Several clinical and inflammatory parameters as well as oxidative stress were evaluated. The results demonstrated that ascorbic acid significantly reduced clinical signs, inflammatory cytokines, myeloperoxidase (MPO) and malonaldehyde (MDA) activities, whereas the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were increased in DSS-induced mice. In addition, ascorbic acid was capable of inhibiting NF-κB, COX-2 and iNOS expression in the colonic. Taken together, these findings suggest that ascorbic acid contributes to the reduction of oxidative stress and inflammatory response in DSS-induced colitis and exerts the potential to prevent and clinical treatment of inflammatory bowel disease.

Measles virus may persist in intestinal tissue, particularly that affected by Crohn's disease, and early exposure to measles may be a risk factor for the development of Crohn's disease. Crohn's disease and ulcerative colitis occur in the same families and may share a common aetiology. In view of the rising incidence of inflammatory bowel disease (Crohn's disease and ulcerative colitis), we examined the impact of measles vaccination upon these conditions. Prevalences of Crohn's disease, ulcerative colitis, coeliac disease, and peptic ulceration were determined in 3545 people who had received live measles vaccine in 1964 as part of a measles vaccine trial. A longitudinal birth cohort of 11,407 subjects was one unvaccinated comparison cohort, and 2541 partners of those vaccinated was another. Compared with the birth cohort, the relative risk of developing Crohn's disease in the vaccinated group was 3.01 (95% CI 1.45-6.23) and of developing ulcerative colitis was 2.53 (1.15-5.58). There was no significant difference between these two groups in coeliac disease prevalence. Increased prevalence of inflammatory bowel disease, but not coeliac disease or peptic ulceration, was found in the vaccinated cohort compared with their partners. These findings suggest that measles virus may play a part in the development not only of Crohn's disease but also of ulcerative colitis.

Nonalcoholic fatty liver disease (NAFLD) develops in ulcerative colitis (UC) and Crohn's disease. However, there is scarce reporting on the onset of UC in patients with NAFLD. A 44-year-old man was diagnosed with UC and referred to us in 2019. His height was 166.0 cm, and body weight was 86.3 kg. The waist circumference was 93.7 cm (normal range<85) and triglyceride was 751 mg/dL. These findings, in addition to hypertension, resulted in a diagnosis of metabolic syndrome. HbA1c was normal. Ultrasonography disclosed severe fatty liver. Nonalcoholic fatty liver disease was diagnosed. He underwent 12 days of educational hospitalization for UC. A lacto-ovo-semi-vegetarian diet (1400 kcal/day), a kind of plant-based diet (PBD), was provided. He lost 4 kg, which was 4.6% of his base body weight. Triglyceride and total cholesterol decreased to the normal ranges. Transaminases andγ-glutamyl transpeptidase also decreased. His body weight decreased further after discharge. Follow-up ultrasonography indicated an improvement in hepatic enlargement. The shear wave velocity decreased from 1.11 to 0.88 m/s. His soft stool became normal stool by 2 months after discharge. Records ofhis health checkups revealed the presence of metabolic syndrome and abnormal liver function tests already in 2015. Thus, it was concluded that UC developed in a patient with NAFLD in this case. Plant-based diet has already been shown to be effective in inflammatory bowel disease (IBD). In the present case, NAFLD parameters were dramatically improved by PBD. Whether the improvement was due to weight loss per se or due to weight loss with PBD is to be clarified.

Ultraviolet (UV) eye irradiation denatures the cells of the intestine. This study examined the action of UVA and UVB on dextran sodium sulfate (DSS)-induced ulcerative colitis. We produced a mouse model of ulcerative colitis by administering DSS for 5 days and irradiated the eye with UVB or UVA for each day of the DSS treatment period. DSS-induced ulcerative colitis was deteriorated by the UVB eye irradiation. Conversely, the symptoms improved with UVA eye irradiation. The levels of adrenocorticotropic hormone (ACTH), corticotropin-releasing hormone (CRH), urocortin 2, interleukin (IL)-18, IL-6 and histamine in the blood increased after the UVB eye irradiation of DSS-treated mice (UVB/DSS-treated mice). In contrast, theβ-endorphin level in the blood of the UVA/DSS-treated mice increased and the levels of urocortin 2, tumor necrosis factor (TNF)-α and histamine decreased. Furthermore, in the colon, the expression of melanocortin-2 receptors (MC2R) increased in the UVB/DSS-treated mice, while the expression of μ-opioid receptors increased in the UVA/DSS-treated mice. When an ACTH inhibitor was administered, UVB eye irradiation caused the deterioration of DSS-treated ulcerative colitis, while the effect of UV eye irradiation disappeared with a μ-opioid receptor antagonist. These results suggested that UV eye irradiation plays an important role in DSS-induced ulcerative colitis.