Suppressive effect of carotenoid extract of Dunaliella salina alga on production of LPS-stimulated pro-inflammatory mediators in RAW264.7 cells via NF-κB and JNK inactivation

Abstract The carotenoid extract from Dunaliella salina was used to evaluate the suppressive effects on lipopolysaccharide (LPS)-induced pro-inflammatory mediators in RAW264.7 cells. The extract composed all- trans forms of α -carotene (28.8 mg/g extract), β -carotene (471.1 mg/g extract), lutein (7.1 mg/g extract) and zeaxanthin (7.2 mg/g extract), 13- or 13′- cis - β -carotene (12.1 mg/g extract), 9- or 9′- cis - α -carotene (19.1 mg/g extract) and 9- or 9′- cis - β -carotene (440.3 mg/g extract) dose-dependently reduced the production of interleukin (IL)-1 β , IL-6 and tumor necrosis factor- α (TNF- α ), the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and the secretion of nitric oxide (NO) and prostaglandin E 2 (PGE 2 ) in LPS-activated RAW264.7 cells. Its attenuation of LPS-induced inflammatory responses was closely related to inhibition of the nuclear NF-κB p50 subunit translocation by blocking inhibitor of κB α (IκB) phosphorylation and degradation correlated with suppressing IκB kinase (IKK) α / β phosphorylation, as well as down-regulation of the c-Jun NH 2 -terminal kinase (JNK) activation.