October 1/Pharma Investments, Ventures & Law Weekly -- According to recent research from Chengdu, People's Republic of China, "Quercetin is a herbal flavonoid derived from various foods of plant origin and widely used as a major constituent of nutritional supplements. Quercetin has been shown to have anti-inflammatory properties and can play a role in anti-inflammatory procedure."

"Intercellular adhesion molecule-1 (ICAM-1) is one of the important pro-inflammatory factors, especially in early phage of inflammation. However, the mechanisms regulating ICAM-1 expression by quercetin in human A549 cells were still unclear. In this study, the inhibitory effect of quercetin on ICAM-1 expression by interleukin-1 beta (IL-1 beta)-stimulated A549 cells was investigated, and the roles of mitogen-activated protein kinases (MAPK) pathways were explored. Quercetin attenuated IL-1 beta-induced expression of ICAM-1 mRNA and protein in a dose-dependent manner. The experiment suggested that quercetin actively inhibited inhibitory protein of nuclear factor-kappa B (I kappa B) degradation, and nuclear factor-kappa B (NF-kappa B) activity. The c-fos and c-jun, components of activator protein-1 (AP-1), were mediated by MAPK pathways. ERK and p38 were involved in the c-fos mRNA expression, and JNK was involved in the c-jun mRNA expression. The inhibitory effect of quercetin on ICAM-1 expression was mediated by the sequential attenuation of the c-fos and c-jun mRNA expressions. These inhibitory effects were partially inhibited by SB203580, a specific inhibitor of p38 MAPK, but not by PD98059, a specific inhibitors of extracellular signal-regulated kinase (ERK), and SP600125, a specific inhibitor of c-Jun-N-terminal kinase (JNK)," wrote B.W. Ying and colleagues, Sichuan University.

The researchers concluded, "Taken together, these results suggest that quercetin negatively modulating ICAM-1 partly dependent on MAPK pathways."

Ying and colleagues published their study in Molecular Biology Reports ("Quercetin Inhibits IL-1 Beta-induced ICAM-1 Expression in Pulmonary Epithelial Cell Line A549 Through the MAPK Pathways." Molecular Biology Reports, 2009;36(7):1825-1832).

For additional information, contact F.Q. Wen, Sichuan University, Division Pulmology Diseases, State Key Laboratory Biotherapy, W China Hospital, W China School Medical, Chengdu 610041, Sichuan, People's Republic of China.

From the October 12, 2009, Prepared Foods E-dition