Suppressive Effect on Lipopolysaccharide-Induced Proinflammatory Mediators by Citrus aurantium L. in Macrophage RAW 264.7 Cells via NF-κB Signal Pathway.
Citrus fruits have been used as an edible fruit and a traditional medicine since ancient times. In particular, the peels of immature citrus fruits are used widely in traditional herbal medicine in Korea, as they are believed to contain bioactive components exerting anti-inflammatory activity. This study examined whether the crude methanol extract of Citrus aurantium L. (CME) has a suppressive effect on inducible enzymes and proinflammatory cytokines by inhibiting the NF-κB pathway in LPS-stimulated macrophage RAW 264.7 cells. The cells were pretreated with the indicated concentrations of CME (5, 10, 20, and 50 μg/mL) and then treated with LPS (1 μg/mL). The results showed that CME (10, 20, and 50 μg/mL) inhibited the LPS- (1 μg/mL) induced mRNA and protein expression of iNOS in macrophage Raw 264.7 cells. In addition, the expression of COX-2 was inhibited at the mRNA and protein levels by CME in a dose-dependent manner. The mRNA expression of proinflammatory cytokines, such as TNF-α and IL-6, were markedly reduced by CME (10, 20, and 50 μg/mL). Moreover, CME clearly suppressed the nuclear translocation of the NF-κB p65 subunits, which was correlated with its inhibitory effect on I-κB phosphorylation. These results suggest that CME has anti-inflammatory properties by modulating the expression of COX-2, iNOS, and proinflammatory cytokines, such as TNF-α and IL-6, in macrophage RAW 264.7 cells via the NF-κB pathway.
Institute of Life Science and College of Veterinary Medicine, Gyeongsang National University, Gazwa, Jinju 660-701, Republic of Korea.
Sang-Rim
SR
Kang
Dae-Yong
DY
Han
Kwang-Il
KI
Park
Hyeon-Soo
HS
Park
Yong-Bae
YB
Cho
Hu-Jang
HJ
Lee
Won-Sup
WS
Lee
Chung Ho
CH
Ryu
Yeong Lae
YL
Ha
Do Hoon
DH
Lee
Jin A
JA
Kim
Gon-Sup
GS
Kim