Inhibition of nitric oxide biosynthesis by anthocyanin fraction of blackberry extract
Section snippets
Anthocyanins contained in blackberry extract
Blackberry fruits were obtained as commercial products. Fruit extract (43.6 g) was obtained by pounding in a mortar about 1 kg of fruits. The extract was centrifuged at 6000 rpm for 20 min, the juice filtered on glass wool, and the pulps extracted overnight with about 1 L of ethyl alcohol (EtOH)/HCl (99:1, v/v) at room temperature. The filtered extract was concentrated under reduced pressure and diluted with water (1:1, v/v). Both the filtered juice and the pulp extract were applied to a C18 silica
Effect of anthocyanin fraction of blackberry extract on LPS-induced nitrite production
To asses whether the anthocyanin fraction of the blackberry extract was able to reduce NO production we utilized the Griess assay to measure nitrite, the stable end-product of NO, in supernatants of the murine macrophage cell line J774 stimulated with LPS (10 μg/ml). A marked increase of nitrite production in the cell medium was observed at 24 h (23.10 ± 0.55 nmol/106 cells; p < 0.001, n = 3) in respect to unstimulated macrophages (3.12 ± 0.40 nmol/106 cells). When the anthocyanin fraction of the
Discussion
Recently, much attention has focused on the protective function of naturally occurring antioxidants in biological systems, and on the mechanisms of their action. Phenolic compounds, which are widely distributed in plants, are considered to play an important role as dietary antioxidants for the prevention of oxidative damage caused, in living systems, by active oxygen radicals.
Anthocyanin pigments are widely distributed in the human diet through crops, beans, fruits, and vegetables, suggesting
Acknowledgments
The authors are grateful to Dr. Antonio Leonardi (Department of Biology and Cellular and Molecular Pathology “L. Califano,” University of Naples Federico II, Naples, Italy) for his advice on EMSA. Thanks are due to the Italian MIUR for financial support (COFIN 2003).
References (47)
- et al.
Antioxidant and prooxidant behaviour of flavonoids: structure–activity relationship
Free Radic. Biol. Med.
(1997) - et al.
Protective effects of cyanidin-3-O-glucoside from blackberry extract against peroxynitrite-induced endothelial dysfunction and vascular failure
Life Sci.
(2003) - et al.
Biosynthesis and action of nitric oxide in mammalian cells
Trends Biochem. Sci.
(1997) - et al.
Chronic infections and inflammatory processes as cancer risk factors: possible role of nitric oxide in carcinogenesis
Mutat. Res.
(1994) - et al.
Nitric oxide synthases: gene structure and regulation
Adv. Pharmacol.
(1995) - et al.
TIS10, a phorbol ester tumor promoter-inducible mRNA from Swiss 3T3 cells, encodes a novel prostaglandin synthase/cyclooxygenase homologue
J. Biol. Chem.
(1991) The inducible transcription activator NF-κB: regulation by distinct protein subunits
Biochim. Biophys. Acta
(1991)- et al.
Molecular mechanism underlying chemopreventive activities of anti-inflammatory phytochemicals: down-regulation of COX-2 and iNOS through suppression of NF-κB activation
Mutation Res.
(2001) - et al.
MEK kinase is involved in tumor necrosis factor alpha-induced NF-κB activation and degradation of IκBα
J. Biol. Chem.
(1996) Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assay
J. Immunol. Methods
(1983)