Effect of natsudaidain isolated from Citrus plants on TNF-alpha and cyclooxygenase-2 expression in RBL-2H3 cells.

Abstract

OBJECTIVES:

Flavonoids inhibit the activity of chemical mediators released from mast cells. Our aim was to investigate the effects of natsudaidain, a polymethoxyflavone isolated from Citrus plants, on mast cells.

METHODS:

We investigated the inhibitory effects of natsudaidain, which is a polymethoxyflavone isolated from Citrus plants, on histamine release, tumour necrosis factor-alpha production and cyclooxygenase-2 expression in Ca ionophore-stimulated rat basophilic leukemia cells (A23187-stimulated RBL-2H3 cells) by spectrofluorometric, ELISA and immunoblotting methods.

KEY FINDINGS:

The percent of histamine release from A23187-stimulated RBL-2H3 cells pretreated with natsudaidain at 5, 25 and 50 microM was not changed as compared with non-treated A23187-stimulated cells. At 100 and 200 microM, natsudaidain pretreatment resulted in slightly reduced histamine release (% histamine release, 89.8+/-3.5% and 71.5+/-5.6% at 100 and 200 microM). Thus, natsudaidain hardly affects histamine release from RBL-2H3 cells, except at high concentrations. On the other hand, natsudaidain dose-dependently inhibited tumour necrosis factor-alpha protein and mRNA levels in A23187-stimulated RBL-2H3 cells; a concentration of 6.8 microM was required for a 50% reduction. In addition, all concentrations of this compound that we tested also inhibited cyclooxygenase-2 protein expression. The mRNA levels of cyclooxygenase-2 in A23187-stimulated RBL-2H3 cells treated with natsudaidain were also markedly decreased. The phosphorylated-p38 MAPK protein levels in A23187-stimulated RBL-2H3 cells treated with natsudaidain were lower than in the non-treated cells.

CONCLUSIONS:

These findings suggest that natsudaidain inhibits tumour necrosis factor-alpha and cyclooxygenase-2 production by suppressing p38 MAPK phosphorylation but not p65 NFkappaB phosphorylation, and that natsudaidain might alleviate inflammatory diseases.

• Authors: Takuya Matsui, Chihiro Ito, Masataka Itoigawa, Tadashi Okada, Hiroshi Furukawa
• Journal: The Journal of pharmacy and pharmacology (J Pharm Pharmacol) Vol. 61 Issue 1 Pg. 109-14 (Jan 2009) ISSN: 0022-3573 [Print] England
• PMID: 19126304 (Publication Type: Evaluation Study, Journal Article)

Chemical References

• Flavones
• Flavonoids
• Ionophores
• RNA, Messenger
• Tumor Necrosis Factor-alpha
• natsudaidain
• Calcimycin
• nobiletin
• Cyclooxygenase 2
• p38 Mitogen-Activated Protein Kinases

Topics

• Analysis of Variance
• Animals
• Calcimycin (pharmacology)
• Cell Line, Tumor
• Chromatography, High Pressure Liquid
• Citrus (chemistry)
• Cyclooxygenase 2 (genetics, metabolism)
• Dose-Response Relationship, Drug
• Enzyme-Linked Immunosorbent Assay
• Flavones (chemistry, isolation & purification, pharmacology)
• Flavonoids (chemistry, isolation & purification, pharmacology)
• Histamine Release (drug effects)
• Immunoblotting
• Ionophores (pharmacology)
• Molecular Structure
• Phosphorylation (drug effects)
• Plant Leaves (chemistry)
• RNA, Messenger (genetics, metabolism)
• Reverse Transcriptase Polymerase Chain Reaction
• Time Factors
• Tumor Necrosis Factor-alpha (genetics, metabolism)
• p38 Mitogen-Activated Protein Kinases (antagonists & inhibitors, drug effects, metabolism)