ABSTRACT
Experimental autoimmune uveitis (EAU) is an animal model of human autoimmune uveitis that is characterized by the infiltration of autoimmune T cells with concurrent increases in pro-inflammatory cytokines and reactive oxygen species. This study aimed to assess whether betaine regulates the progression of EAU in Lewis rats. EAU was induced via immunization with the interphotoreceptor retinoid-binding protein (IRBP) and oral administration of either a vehicle or betaine (100 mg/kg) for 9 consecutive days. Spleens, blood, and retinas were sampled from the experimental rats at the time of sacrifice and used for the T cell proliferation assay, serological analysis, real-time polymerase chain reaction, and immunohistochemistry. The T cell proliferation assay revealed that betaine had little effect on the proliferation of splenic T cells against the IRBP antigen in an in vitro assay on day 9 post-immunization. The serological analysis showed that the level of serum superoxide dismutase increased in the betainetreated group compared with that in the vehicle-treated group. The anti-inflammatory effect of betaine was confirmed by the downregulation of pro-inflammation-related molecules, including vascular cell adhesion molecule 1 and interleukin-1β in the retinas of rats with EAU. The histopathological findings agreed with those of ionized calcium-binding adaptor molecule 1 immunohistochemistry, further verifying that inflammation in the retina and ciliary bodies was significantly suppressed in the betaine-treated group compared with the vehicle-treated group. Results of the present study suggest that betaine is involved in mitigating EAU through anti-oxidation and anti-inflammatory activities.
ABSTRACT
Experimental autoimmune uveitis (EAU) is an animal model of human autoimmune uveitis that is characterized by the infiltration of autoimmune T cells with concurrent increases in pro-inflammatory cytokines and reactive oxygen species. This study aimed to assess whether betaine regulates the progression of EAU in Lewis rats. EAU was induced via immunization with the interphotoreceptor retinoid-binding protein (IRBP) and oral administration of either a vehicle or betaine (100 mg/kg) for 9 consecutive days. Spleens, blood, and retinas were sampled from the experimental rats at the time of sacrifice and used for the T cell proliferation assay, serological analysis, real-time polymerase chain reaction, and immunohistochemistry. The T cell proliferation assay revealed that betaine had little effect on the proliferation of splenic T cells against the IRBP antigen in an in vitro assay on day 9 post-immunization. The serological analysis showed that the level of serum superoxide dismutase increased in the betainetreated group compared with that in the vehicle-treated group. The anti-inflammatory effect of betaine was confirmed by the downregulation of pro-inflammation-related molecules, including vascular cell adhesion molecule 1 and interleukin-1β in the retinas of rats with EAU. The histopathological findings agreed with those of ionized calcium-binding adaptor molecule 1 immunohistochemistry, further verifying that inflammation in the retina and ciliary bodies was significantly suppressed in the betaine-treated group compared with the vehicle-treated group. Results of the present study suggest that betaine is involved in mitigating EAU through anti-oxidation and anti-inflammatory activities.
ABSTRACT
We investigated the antihypertensive effect of lutein on NG-nitro-L-arginine methyl ester hydrochloride (L-NAME)-induced hypertensive rats. Daily oral administration of L-NAME (40 mg/kg)-induced a rapid progressive increase in mean arterial pressure (MAP). L-NAME significantly increased MAP from the first week compared to that in the control and reached 193.3+/-9.6 mmHg at the end of treatment. MAP in the lutein groups was dose-dependently lower than that in the L-NAME group. Similar results were observed for systolic and diastolic blood pressure of L-NAME-induced hypertensive rats. The control group showed little change in heart rate for 3 weeks, whereas L-NAME significantly reduced heart rate from 434+/-26 to 376+/-33 beats/min. Lutein (2 mg/kg) significantly prevented the reduced heart rate induced by L-NAME. L-NAME caused hypertrophy of heart and kidney, and increased plasma lipid peroxidation four-fold but significantly reduced plasma nitrite and glutathione concentrations, which were significantly prevented by lutein in a dose-dependent manner. These findings suggest that lutein affords significant antihypertensive and antioxidant effects against L-NAME-induced hypertension in rats.