Sang-Kwan Lee, Jungmi Kim, G. Seo
Jan 24, 2009
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4
Influential Citations
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Quality indicators
Journal
Inflammation Research
Abstract
Abstract.Objectives:Isoliquiritigenin (ISL), one of the major constituents of Dalbergia odorifera T. Chen (Leguminosae), is reported to exert anti-inflammatory effects, but the relevant anti-inflammatory mechanisms are not completely understood. Heme oxygenase-1 (HO-1) has been proven to be involved in the resolution of inflammatory responses. In this study, we investigated whether ISL could induce HO-1 expression in RAW264.7 macrophages, and if so, whether HO-1 could mediate the anti-inflammatory effects of ISL.Methods:The protein expression of inducible nitric oxide synthase and HO-1 was analyzed by western blot analysis. The production of nitric oxide (NO) and interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) was assayed by Griess and ELISA, respectively. The TNF-α and HO-1 mRNA expression was analyzed by northern blot analysis.Results:ISL markedly suppressed LPS-induced NO, IL-1β, and TNF-α production. ISL induced HO-1 expression through the extracellular signal-regulated kinase1/2 pathway in RAW264.7 macrophages. The effects of ISL on LPS-induced NO and TNF-α production were reversed by the HO-1 inhibitor, tin protoporphyrin.Conclusions:ISL is an effective HO-1 inducer capable of inhibiting macrophage-derived inflammation.