BackgroundInflammation has been found to be associated with many neurodegenerative diseases, including Parkinson’s and dementia. Attenuation of microglia-induced inflammation is a strategy that impedes the progression of neurodegenerative diseases.MethodsWe used lipopolysaccharide (LPS) to simulate murine microglia cells (BV2 cells) as an experimental model to mimic the inflammatory environment in the brain. In addition, we examined the anti-inflammatory ability of corylin, a main compound isolated from Psoralea corylifolia L. that is commonly used in Chinese herbal medicine. The production of nitric oxide (NO) by LPS-activated BV2 cells was measured using Griess reaction. The secretion of proinflammatory cytokines including tumor necrosis factor (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) by LPS-activated BV2 cells was analyzed using enzyme-linked immunosorbent assay (ELISA). The expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3), apoptosis-associated speck-like protein containing a caspase-activation and recruitment domain (ASC), caspase-1, IL-1β and mitogen-activated protein kinases (MAPKs) in LPS-activated BV2 cells was examined by Western blot.ResultsOur experimental results demonstrated that corylin suppressed the production of NO and proinflammatory cytokines by LPS-activated BV2 cells. In addition, corylin inhibited the expression of iNOS and COX-2, attenuated the phosphorylation of ERK, JNK and p38, decreased the expression of NLRP3 and ASC, and repressed the activation of caspase-1 and IL-1β by LPS-activated BV2 cells.ConclusionOur results indicate the anti-inflammatory effects of corylin acted through attenuating LPS-induced inflammation and inhibiting the activation of NLRP3 inflammasome in LPS-activated BV2 cells. These results suggest that corylin might have potential in treating brain inflammation and attenuating the progression of neurodegeneration diseases.
Shikonin is a naphthoquinone isolated from the dried root of Lithospermum erythrorhizon, an herb used in Chinese medicine. Although several studies have indicated that shikonin exhibits antitumor activity in breast cancer, the mechanism of action remains unclear. In the present study, we performed transcriptome analysis using RNA-seq and explored the mechanism of action of shikonin in regulating the growth of different types of breast cancer cells. The IC 50 of shikonin on MCF-7, SKBR-3 and MDA-MB-231 cells were 10.3 μΜ, 15.0 μΜ, 15.0 μΜ respectively. Our results also demonstrated that shikonin arrests the progression of cell cycle and induces apoptosis in MDA-MB-231 cells. Using RNAseq transcriptome analysis, we found 38 common genes that significantly express in different types of breast cancer cells under shikonin treatment. In particular, our results indicated that shikonin induces the expression of dual specificity phosphatase (DUSP)-1 and DUSP2 in both RNA and protein levels. In addition, shikonin also inhibits the phosphorylation of JNK and p38, the downstream signaling molecules of DUSP1 and DUSP2. Therefore, our results suggest that shikonin induces the expression of DUSP1 and DUSP2 which consequently switches off JNK and p38 MAPK pathways and causes cell cycle arrest and apoptosis in breast cancer cells.Breast cancer is one of the most common cancers and the second leading cause of cancer death among women in the United States 1 . One in eight women will be diagnosed with breast cancer in her lifetime. Approximately 70% of breast cancer patients are inoperable because of advanced tumor growth or bone metastasis 2 . Therefore, new strategies for the treatment of breast cancer are necessary. Many agents extracted from Traditional Chinese medicine (TCM) have been shown to possess anticancer activities and can be considered as alternative treatments for breast cancer 3 .Shikonin, a naphthoquinone isolated from the Chinese herbal plant Lithospermum erythrorhizon, has been used to treat a variety of inflammatory and infectious diseases 4 . Several biological and pharmacological actions of shikonin have been reported, including anti-inflammatory 5 , antibacterial 6 , antiviral 7 , and antioxidant 8 activities. In particular, shikonin has been shown to exert anticancer properties via different mechanisms on various
Effectively directing the chondrogenesis of adipose-derived stem cells (ADSCs) to engineer articular cartilage represents an important challenge in ADSC-based articular cartilage tissue engineering. The discoidin domain receptor 1 (DDR1) has been shown to affect cartilage homeostasis; however, little is known about the roles of DDR1 in ADSC chondrogenesis. In this study, we used the three-dimensional culture pellet culture model system with chondrogenic induction to investigate the roles of DDR1 in the chondrogenic differentiation of human ADSCs (hADSCs). Real-time polymerase chain reaction and Western blot were used to detect the expression of DDRs and chondrogenic genes. Sulfated glycosaminoglycan (sGAG) was detected by Alcian blue and dimethylmethylene blue (DMMB) assays. Terminal deoxy-nucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining was used to assess cell death. During the chondrogenesis of hADSCs, the expression of DDR1 but not DDR2 was significantly elevated. The depletion of DDR1 expression in hADSCs using short hairpin RNA increased the expression of chondrogenic genes (SOX-9, collagen type II, and aggrecan) and cartilaginous matrix deposition (collagen type II and sGAG) and only slightly increased cell death (2-8%). DDR1 overexpression in hADSCs decreased the expression of chondrogenic genes (SOX-9, collagen type II, and aggrecan) and sGAG and enhanced hADSC survival. Moreover, DDR1-depleted hADSCs showed decreased expression of the terminal differentiation genes runt-related transcription factor 2 (Runx2) and matrix metalloproteinase 13 (MMP-13). These results suggest that DDR1 suppression may enhance ADSC chondrogenesis by enhancing the expression of chondrogenic genes and cartilaginous matrix deposition. We proposed that the suppression of DDR1 in ADSCs may be a candidate strategy of genetic modification to optimize ADSC-based articular cartilage tissue engineering.
We describe herein the preparation of certain 2-substituted 3-arylquinoline derivatives and the evaluation of their anti-inflammatory effects in LPS-activated murine J774A.1 macrophage cells. Among these newly synthesized 2-substituted 3-arylquinoline derivatives, 2-(4-methoxy- benzoyl)-3-(3,4,5-trimethoxyphenyl)quinoline (18a) and 2-(4-fluorobenzoyl)-3-(3,4,5-trimethoxy- phenyl)quinoline (18b) are two of the most active compounds which can inhibit the production of NO at non-cytotoxic concentrations. Our results have also indicated that compounds 18a and 18b significantly decrease the secretion of pro-inflammatory cytokines (TNF-á and IL-6), inhibit the expression of iNOS, suppress the phosphorylation of MAPKs, and attenuate the activity of NF-êB by LPS-activated macrophages. Through molecular docking analysis, we found that 18b could fit into the middle of the TNF-á dimer and form hydrophobic interactions with Leu55, Leu57 chain A and B, Tyr59, Val123 chain B and D, Ile 155. These results suggest that both 18a and 18b are potential lead compounds in inhibiting LPS-induced inflammatory responses. Further structural optimization to discover novel anti-inflammatory agents is ongoing.
The inflammatory response of macrophages is involved in pathogenesis of lifestyle-related diseases. Green tea consumption reduces the incidence of lifestyle-related diseases. This study investigated the anti-inflammatory effect of polyphenols of green tea including gallic acid, (+)-catechin, (-)-catechin, (-)-epicatechin and (-) epigallocatechin-3-gallate (EGCG) in vitro. The macrophage cell line RAW264 cells were pre-treated with different concentrations of polyphenols (gallic acid, (+)-catechin, (-)-catechin, (-)-epicatechin and EGCG) for 4 h, and were stimulated with LPS for 45 min, 2 h and 24 h. After 24 h LPS challenge, cell lysates and supernatants were harvested. The protein concentration of whole cell lysate was used for determination of cell growth/viability by the BCA assay. The production of TNF-? and IL-6 was measured by ELISA. The total expression and phosphorylation of p38 MAPK was detected by Western blotting. Our results showed that the total protein content of cells was decreased after LPS challenge, while this effect was attenuated when cells were pre-treated with 10 ?M gallic acid and EGCG. Pre-treatment with 1 and 10 ?M EGCG and (-)-catechin significantly decreased the production of TNF-? and IL-6. Furthermore, pre-treatment with 10 ?M gallic acid significantly reduced the production of TNF-? and IL-6. Pre-treatment with 10 ?M (+)-catechin, (-)-catechin, (-) epicatechin, and EGCG enhanced the expression and phosphorylation of p38 MAPK after stimulation with LPS for 45 min and 2 h. By contrast, pre-treatment with gallic acid did not affect the production and phosphorylation of p38 MAPK. These results demonstrated that polyphenols with pyrogallol-type structures in green tea attenuate the activation of macrophages.
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