Protective effect of dried safflower petal aqueous extract and its main constituent, carthamus yellow, against lipopolysaccharide-induced inflammation in RAW264.7 macrophages

BACKGROUND: Safflower, whose botanic name is Carthamus tinctorius L., is a member of the family Compositae or Asteraceae. Carthamus yellow (CY) is the main constituent of safflower and is composed of safflomin A and safflomin B. Dried safflower petals are used in folk medicine and have been shown to invigorate blood circulation, break up blood stasis, and promote menstruation. In addition, dried safflower petals contain yellow dyes that are used to color food and cosmetics. In this study, we investigated the effects of dried safflower petals aqueous extracts (SFA) and CY on lipopolysaccharide (LPS)-induced inflammation using RAW264.7 macrophages. RESULTS: Our data showed that treatment with SFA (1–1000 µg mL−1) and CY (1–2000 µg mL−1) does not cause cytotoxicity in cells. SFA and CY inhibited LPS-stimulated nitric oxide (NO), prostaglandin E2 (PGE2), and interleukin 1β (IL-1β) release, through attenuation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein expression. Further, SFA and CY suppressed the LPS-induced phosphorylation of nuclear factor-κB, which was associated with the inhibition of IκB-α degradation. CONCLUSION: These results suggest that SFA and CY provide an anti-inflammatory response through inhibiting the production of NO and PGE2 by the downregulation of iNOS and COX-2 gene expression. Thus safflower petals have the potential to provide a therapeutic approach to inflammation-associated disorders. Copyright © 2010 Society of Chemical Industry