licochalcone-a and indicine

Licorice root has been used as a traditional medicine for the treatment of gastric ulcer, bronchial asthma and inflammation. Licochalcone A is a major component of Xinjiang licorice, Glycyrrhiza inflata. Previously we showed that Licochalcone A significantly inhibited LPS-induced NF-kappaB transcriptional activation by abrogating the phosphorylation of NF-kappaB p65 at serine 276. Glycyrrhiza inflata contains not only Licochalcone A but also Licochalcone B, Licochalcone C, Licochalcone D, Echinatin and Isoliquiritigenin, harboring the common structure of chalcones. No chalcones had any effect on LPS-induced IkappaB degradation, nuclear translocation and DNA binding activity of NF-kappaB p65; however, we observed that Licochalcone B and Licochalcone D significantly inhibited LPS-induced phosphorylation at serine 276 and transcriptional activation of NF-kappaB, the same as Licochalcone A. Interestingly, we also found that Licochalcone A, Licochalcone B and Licochalcone D effectively inhibited LPS-induced activation of PKA, which is required for the phosphorylation of NF-kappaB p65 at serine 276. Consequently, Licochalcone B and Licochalcone D significantly reduced the LPS-induced production of NO, TNFalpha and MCP-1. On the other hand, Licochalcone C, Echinatin and Isoliquitigenin failed to inhibit LPS-induced NF-kappaB activation. These findings suggest that the anti-inflammatory effect of Glycyrrhiza inflata is ascribable to the potent inhibition of NF-kappaB by Licochalcone A, Licochalcone B and Licochalcone D.

Topics: Animals; Cell Line; Chalcones; Chemokine CCL2; Cyclic AMP-Dependent Protein Kinases; Glycyrrhiza; Lipopolysaccharides; Macrophages; Mice; Nitric Oxide; Nitric Oxide Synthase Type II; Phosphorylation; Pyrrolizidine Alkaloids; Signal Transduction; Transcription Factor RelA; Tumor Necrosis Factor-alpha