Jae-Chan Song

Quercetin suppresses proinflammatory cytokines production through MAP kinases and NF-κB pathway in lipopolysaccharide-stimulated macrophage

Quercetin is a flavonoid molecule ubiquitous in nature and functions as an anti-oxidant and anti-inflammatory agent with little toxicity in vivo and in vitro. Dose- and time-dependent effect of quercetin has been investigated on proinflammatory cytokine expression and NO production, focusing on its effects on the MAP kinases and the NF-κB signal transduction pathways in LPS-stimulated RAW 264.7 cells by using RT-PCR and immunoblotting. Quercetin strongly reduced activation of phosphorylated ERK kinase and p38 MAP kinase but not JNK MAP kinase by LPS treatment. In addition, quercetin treatment inhibited NF-κB activation through stabilization of the NF-κB/IκB complex and IκB degradation and proinflammatory cytokines and NO/iNOS expression. Quercetin may exert its anti-inflammatory and immunomodulatory properties in the effect molecules such as proinflammatory cytokines and NO/iNOS by suppressing the activation of ERK and p38 MAP kinase, and NF-κB/IκB signal transduction pathways.

Radical scavenging and anti-inflammatory activity of extracts from Opuntia humifusa Raf.

Opuntia humifusa Raf. (O. humifusa Raf.) is a member of the Cactaceae family. To determine the antioxidative and anti‐inflammatory effects of this herb, various solvent fractions (methanol, hexane, chloroform, ethyl acetate, butanol, and water) prepared from the leaves of cacti were tested using DPPH (2,2‐diphenyl‐l‐picrylhydrazyl radical) and xanthine oxidase assays, and nitric oxide (NO)‐producing macrophage cells. We found that O. humifusa Raf. displayed potent antioxidative and anti‐inflammatory activity. Thus, all solvent fractions, except for the water layer, showed potent scavenging effects. The scavenging effect of the ethyl acetate fraction was higher than that of the other fractions, with IC50 values of 3.6 and 48.2 μg mL−1. According to activity‐guided fractionation, one of the active radical scavenging principles in the ethyl acetate fraction was found to be quercetin. In contrast, only two fractions (chloroform and ethyl acetate) significantly suppressed nitric oxide production from the lipopolysaccharide (LPS)‐activated RAW264.7 cells. In addition, chloroform and ethyl acetate fractions significantly blocked the expression of inducible nitric oxide synthetase (iNOS) and interleukin‐6 (IL‐6) from the RAW264.7 cells stimulated by LPS. Moreover, ethyl acetate fractions significantly blocked the expression of IL‐1β from the RAW264.7 cells stimulated by LPS. Therefore, the results suggested that O. humifusa Raf. may modulate radical‐induced toxicity via both direct scavenging activity and the inhibition of reactive species generation, and the modulation of the expression of inflammatory cytokines. Finally, O. humifusa Raf. may be useful as a functional food or drug against reactive species‐mediated disease.

Bulnesia Sarmienti Aqueous Extract Inhibits Inflammation in LPS-Stimulated RAW 264.7 Cells

Bulnesia sarmienti (BS), a traditional South American herbal medicine native to Gran Chaco, has been used to treat various human ailments. We investigated the cytotoxic activities and the inhibitory effects of BS bark extract(0, 50, 100 and ) on the production of nitric oxide (NO), prostaglandin (), cyclooxygenase (COX) and proinflammatory cytokines (, IL-6 and ) in the lipopolysaccharide (LPS) (100 ng/ml)-stimulated murine macrophage cell line RAW264.7. The levels of NO, COX, PGE2 production and proinflammatory cytokines (, IL-6 and ) were measured by ELISA kit. Cell viability, as measured by the MTT assay, showed that BS extract had no significant cytotoxicity in RAW264.7 cells. BS extract significantly inhibited the LPS-induced NO, and COX production accompanied by an attenuation of , IL-6 and formation in macrophages. These results suggest that BS extract has potential as an herbal medicine for the treatment of inflammatory diseases.

Anticancer Activity and Apoptotic Effects of Bulnesia sarmienti against Human Lung Cancer H460 Cells

Bulnesia sarmienti (BS), a traditional South American herbal medicine native to Gran Chaco, has been used to treat various human ailments. The effects of BS aqueous extract (100, 200, and 400 microg/ml) on H460 cell lines were investigated. High-performance liquid chromatography (HPLC) confirmed that BS contains catechins as major compound. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, cell cycle analysis, DNA fragmentation, apoptosis, and immunoblot analysis on cells were carried out. BS has strong cytotoxic activity on the H460 cell lines (IC50; less than 100 microg/ml) in MTT assay. Flow cytometry indicated that BS arrested the cell cycle in the sub-G1 phase. When BS was treated on H460 cells, DNA fragmentation was increased, and early apoptotic cells were shown to be positive by annexin V staining. Also, the expressions of the p53 and Bax were increased and Bcl-2 protein was downregulated with BS treatment. These results indicated that the BS has anticancer activity on H460 cells and BS may be useful in future therapeutic applications for developing anticancer agents.

Hepatoprotective Effects of Polysaccharides Isolated from Phellinus gilvus Against Carbon Tetrachloride-induced Liver Injury in Rats

Phellinus gilvus (PG) is a widely used mushroom for health promotion. We studied the hepatoprotective effect of the polysaccharide aqueous extract of PG (PGP) against carbon tetrachloride (CCl4)-induced liver injury in rats. Sprague Dawley rats were divided into 5 groups: Normal control, CCl4 control, PGP 50, 100, and 200 mg/kg + CCl4. The levels of serum biochemical parameters, liver lipid peroxide and antioxidant enzymes, and histological appearances were evaluated. The CCl4-induced increments of alanine aminotransferase, asparate aminotransferase, and alkaline phosphatase levels in serum were significantly decreased by PGP-pretreatments. The PGP dose-dependently decreased hepatic malondialdehyde formations in CCl4-treatment groups. Hepatic antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) were elevated by PGP in CCl4-treatment groups. Histopathological evaluation of liver showed that the loss of hepatocytes, fatty changes, swelling and extensive necrosis of hepatocytes in centrilobular regions of the CCl4-treated rats were ameliorated by PGP pretreatment. The PGP has hepatoprotective and antioxidative effects in CCl4-induced liver injury of rat.