Anti-inflammation Response of Astaxanthin on Inhibiting Nuclear Factor Kappa B Activation

Objectives: Oral lichen planus (OLP) is a chronic inflammatory disease⁽¹⁾ that affects the mucous membrane of the oral cavity and a T cell mediated autoimmune disease in which the cytotoxic CD8⁺ T cells trigger apoptosis of the keratinocyte is considered. The cytokine mediated lymphocyte homing mechanism plays an important role in the pathogenesis of lichen planus. Some of the cytokines such as interleukin (IL)-1, IL-6 and tumor necrosis factor (TNF)-α that are responsible for the up-regulation of the adhesion molecules. On the other hand, Astaxanthin (AX) is known as a kind of carotenoid and having a capacity of anti-inflammation and anti-oxidant⁽²⁾. In this study, to improve of pathology on OLP we evaluated the anti-inflammatory effects of AX for chronic inflammation with lipopolysaccaride (LPS) derived on Escherichia coli O55 on human gingival keratinocyte NDUSD-1.

Methods: Immortalized human gingival keratinocyte (NDUSD-1) were cultured in keratinocyte serum free medium (K-SFM) on 24 well flat bottom. LPS was used as inflammatory stimulation. Before or after LPS stimulation, AX was treated for NDUSD-1. After cell early adhesion (dissemination after one day), AX treatment group (Post-AX) was replaced to 100 µg/mL LPS added with medium and initiated inflammation until for 24 h. Subsequently, Post-AX was displaced 10 µM AX added with medium time point at 0, 48, 96 h. Control group for Post-AX was cultured in K-SFM. On the other hand, after early adhesion, AX prevention group (Pre-AX) was replaced to AX added with medium and acted until for 24 h. Subsequently, Pre-AX was displaced LPS added with medium time point at 0, 48, 96 h. Control group for Pre-AX was cultured in LPS added with medium. Cell supernatant fluid and cell pellet were collected each time point. Measurement was performed using immunofluorescence for nuclear factor kappa-B (NF-κB)/p65 and quantity of NF-κB/p65 into the cytoplasm or nucleus, enzyme-linked immunosorbent assay (ELISA) for inflammatory cytokines (IL-1β, IL-6, TNF-α) and cell proliferation. The data are presented as means ± standard deviations (SD). The Tukey HSD (honestly significant difference) test or Student’s t-test for unpaired results was used to evaluate differences between two groups respectively. Differences were considered to be significant for values of less than 5% (p<0.05).  

Results: Quantity of the NF-κB/p65 into the cytoplasm was significantly increased in Pre-AX. Pre-AX of that into the nucleus was tended to be the down-regulation compared with control group. But the difference significant was not accepted between Pre-AX and control group or Post-AX and control group. Production of IL-6 on Pre-AX was decreased significantly onward 24 h compared with control group. Also, production of TNF-α on Post-AX was decreased significantly at 1, 12 h compared with control group. Cell proliferation of Pre-AX was increased significantly until 12 h compared with control group and Post-AX was increased significantly onward 24 h compared with control group.

Conclusion: As a result, effect of anti-inflammation by down-regulation of NF-κB/p65 was detected by preventive and curative administration of AX.  Therefore, AX may be improved the inflammation of OLP. (492 words)

1. Roopashree MR, Gondhalekar RV, Shashikanth MC, George J, Thippeswamy SH, Shukla A. Pathogenesis of oral lichen planus--a review. J Oral Pathol Med. 2010 Nov;39(10):729-34.

2. Park JS, Chyun JH, Kim YK, Line LL, Chew BP. Astaxanthin decreased oxidative stress and inflammation and enhanced immune response in humans. Nutr Metab (Lond). 2010;7:18.