• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.211-219
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• 2020

Quercetin is a polyphenol compound with excellent antioxidant and anti-inflammatory activity. However, little has been reported about the efficacy of quercetin to control psoriasis. Thus, we aimed to investigate the effect of quercetin to regulate psoriatic dermatitis with HaCaT cell lines activated by TNF-α and IL-17A, which are in vitro psoriasis skin models. When quercetin was treated with TNF-α-activated HaCaT cell line, inflammatory cytokine expressions such as IL-1α, IL-1β and IL-6 were reduced by 49.1±7.14, 42.8±8.16, and 34.5±2.52%, respectively. In addition, mRNA expression levels of IL-8 and CCL20 the chemokines that attract immune cells such as Th17 cells and dendritic cells to the inflammatory reaction site, were also reduced by 38.4±5.83 and 52.9±4.59% compared to the TNF-α treatment group. The expression of proteins KRT6A and KRT16, which was nonspecifically increased in psoriatic skin was also significantly suppressed. Moreover, phosphorylation of IκBα and STAT3 proteins activated by TNF-α was also significantly inhibited. After stimulating the HaCaT with IL-17A, known as another psoriasis-inducing cytokine, it was observed that IκBα mRNA expression decreased by 55.8±5.28%, and STAT3 phosphorylation was downregulated by 36.3±6.81%. Finally, after co-activation by TNF-α/IL-17A, quercetin inhibited all of IL-1α, IL-1β, IL-6, TNF-α and CCL20 gene expression. The above results strongly suggest that quercetin is a material that has not only anti-oxidant and anti-inflammatory activities, but also has an activity in improving psoriasis.

• Food Science and Preservation
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• v.25 no.1
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• pp.107-116
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• 2018

The aim of this study is to investigate the antioxidant and intracellular anti-inflammatory efficacy of blueberry leaf extracted with hot water (BLW), 70% ethanol (BLE), and 70% acetone (BLA) in RAW 264.7 macrophages. In order to evaluate the anti-inflammatory effect of blueberry leaf extracts, RAW 264.7 macrophages were stimulated with lipopolysaccharide (LPS) to induce the production of inflammation-related factors, which were measure by Western blotting and real-time PCR methods. i-NOS, COX-2 protein, and mRNA expression showed concentration-dependent decrease. The decreases in the mRNA expression levels of interleukin-$1{\beta}$ (IL-$1{\beta}$), interleukin-6 (IL-6), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and prostaglandin $E_2$ ($PGE_2$) were concentration-dependent. Further, the antioxidant effects of blueberry leaf on total polyphenol contents, electron donating ability and $ABTS^+$ radical scavenging activity were evaluated. The total polyphenol contents of BLW, BLE, and BLA were $217.04{\pm}2.98$, $156.72{\pm}3.90$, and $182.88{\pm}3.02mg\;TAE/g$, respectively, while the electron donating abilities at $1,000{\mu}g/mL$ of BLW, BLE, and BLA were 81.7, 79.6, and 79.3%, respectively. The $ABTS^+$ radical scavenging activity was fond to be concentration dependent. The nitric oxide (NO) production inhibition activities at $50{\mu}g/mL$ of BLW, BLE, and BLA were 35.1, 42.4 and 42.7%, respectively. In conclusion, the antioxidant and anti-inflammatory test results indicate that blueberry leaf extracts (BLW, BLE, and BLA) can be used as potential anti-inflammatory agents.