Red ginseng acidic polysaccharide (RGAP), isolated from Korean red ginseng, displays immunostimulatory and antitumor activities. Even though numerous studies have been reported, the mechanism as to how RGAP is able to stimulate the immune response is not clear. In this study, we aimed to explore the mechanism of molecular activation of RGAP in macrophages. RGAP treatment strongly induced NO production in RAW264.7 cells without altering morphological changes, although the activity was not strong compared to LPS-induced dendritic-like morphology in RAW264.7 cells. RGAP-induced NO production was accompanied with enhanced mRNA levels of iNOS and increases in nuclear transcription factors such as NF-κB, AP-1, STAT-1, ATF-2, and CREB. According to pharmacological evaluation with specific enzyme inhibitors, Western blot analysis of intracellular signaling proteins and inhibitory pattern using blocking antibodies, ERK, and JNK were found to be the most important signaling enzymes compared to LPS signaling cascade. Further, TLR2 seems to be a target surface receptor of RGAP. Lastly, macrophages isolated from RGS2 knockout mice or wortmannin exposure strongly upregulated RGAP-treated NO production. Therefore, our results suggest that RGAP can activate macrophage function through activation of transcription factors such as NF-κB and AP-1 and their upstream signaling enzymes such as ERK and JNK.
The Rheum palmatum L., a traditional medicine in Korea, was screened for their estrogenic activity in a recombinant yeast system with a human estrogen receptor (ER) expression plasmid and a reporter plasmid used in a previous study. The EC50 values of the n-hexane, dichloromethane, ethyl acetate, n-butanol, and water fractions of the methanolic extract of R. palmatum in the yeast-based estrogenicity assay system were 0.145, 0.093, 0.125, 1.459, 2.853 microg/mL, respectively, with marked estrogenic activity in the dichloromethane fraction. Using an activity-guided fractionation approach, five known anthraquinones, chrysophanol (1), physcion (2), emodin (3), aloe-emodin (4) and rhein (5), were isolated from the dichloromethane fraction. Compound 3 had the highest estrogenic relative potency (RP, 17bestradiol = 1.00) (6.3 x 10(-2)), followed by compound 4 (3.8 x 10(-3)), compound 5 (2.6 x 10(-4)), a compound 1 (2.1 x 10(-4)). Also, compound 3 and fraction 3 (which contained compound 3) of the dichloromethane fraction of R. palmatum showed strong cytotoxicity in both ER-positive (MCF-7) and-negative (MDA-MB-231) breast cancer cell lines.
Inflammation is a complex protective response of body tissues to harmful stimuli. Acute inflammation can progress to chronic inflammation, which can lead to severe disease. Therefore, this research focuses on the development of anti-inflammatory drugs, and natural extracts have been explored as potential agents. No study has yet examined the inflammation-associated pharmacological activity of Potentilla glabra Var. mandshurica (Maxim.) Hand.-Mazz ethanol extract (Pg-EE). To examine the mechanisms by which Pg-EE exerts anti-inflammatory effects, we studied its activities in lipopolysaccharide (LPS)-treated murine macrophage RAW264.7 cells and an HCl/EtOH-induced gastritis model. LPS-triggered nitric oxide (NO) release and mRNA levels of inducible nitric oxide synthase (iNOS), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) in RAW264.7 cells were suppressed by Pg-EE in a dose-dependent manner. Using a luciferase assay and western blot assay, we found that the NF-κB pathway was inhibited by Pg-EE, particularly by the decreased level of phosphorylated proteins of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) subunits (p65 and p50), inhibitor of kappa B alpha (IκBα), p85, and Src. Using an overexpression strategy, cellular thermal shift assay, and immunoprecipitation analysis, we determined that the anti-inflammatory effect of Pg-EE was mediated by the inhibition of Src. Pg-EE further showed anti-inflammatory effects in vivo in the HCl/EtOH-induced gastritis mouse model. In conclusion, Pg-EE exerts anti-inflammatory activities by targeting Src in the NF-κB pathway, and these results suggest that Pg-EE could be used as an anti-inflammatory herbal medicine.
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