Effects of Lutein and Zeaxanthin on LPS-Induced Secretion of IL-8 by Uveal Melanocytes and Relevant Signal Pathways.

Shih-Chun Chao,Tommaso Vagaggini,Hung-Yu Lin,Sheng-Chieh Huang,Chan-Wei Nien

doi:10.1155/2015/152854

Abstract

The effects of lutein and zeaxanthin on lipopolysaccharide- (LPS-) induced secretion of IL-8 by uveal melanocytes (UM) were tested in cultured human UM. MTT assay revealed that LPS (0.01–1 μg/mL) and lutein and zeaxanthin (1–10 μM) did not influence the cell viability of cultured UM. LPS caused a dose-dependent increase of secretion of IL-8 by cultured UM. Lutein and zeaxanthin did not affect the constitutive secretion of IL-8. However, lutein and zeaxanthin decreased LPS-induced secretion of IL-8 in cultured UM in a dose-dependent manner. LPS significantly increased NF-κB levels in cell nuclear extracts and p-JNK levels in the cell lysates from UM, but not p-p38 MAPK and p-ERG. Lutein or zeaxanthin significantly reduced LPS-induced increase of NF-κB and p-JNK levels, but not p38 MAPK and ERG levels. The present study demonstrated that lutein and zeaxanthin inhibited LPS-induced secretion of IL-8 in cultured UM via JNK and NF-κB signal pathways. The anti-inflammatory effects of lutein and zeaxanthin might be explored as a therapeutic approach in the management of uveitis and other inflammatory diseases of the eye.

Highlights

Zeaxanthin and lutein are two natural bioactives that belong to the xanthophyll class
Quantikine IL-8 Enzyme-linked immunosorbent assay (ELISA) kit was obtained from R&D System (Minneapolis, MN, USA). p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinases 1/2 (ERK1/2), and c-Jun N-terminal kinase 1/2 (JNK1/2) ELISA kits and cell extraction buffer, PMSF, hypotonic buffer, and nuclear factor-kappa B (NF-κB) ELISA kits were obtained from Invitrogen (Carlsbad, CA, USA)
Lutein and zeaxanthin at the final levels of 1, 3, and 10 μM had no effects on the cell viability of cultured uveal melanocytes (UM) (p > 0.05, compared with cells not treated with LPS) (Figures 1(b) and 1(c))

Summary

Introduction

Zeaxanthin and lutein are two natural bioactives that belong to the xanthophyll class. They are present in the eye in high concentrations. There is increasing evidence that lutein and zeaxanthin may play an important role in protecting against several eye diseases, such as age-related macular degeneration (AMD) [3,4,5,6,7,8]. Lutein and zeaxanthin are widely used as nutrient supplements for the prevention and treatment of AMD and other eye diseases. The protective effects of lutein and zeaxanthin may be related to their short wave lightscreening effect and antioxidant properties [1,2,3,4,5,6,7,8,9]. It has been reported that lutein can suppress the development of uveitis caused by injection of lipopolysaccharide (LPS) in rats and mice [10, 11]

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Results

Conclusion