Flavonoids and stilbenoids as a promising arsenal for the management of chronic arsenic toxicity

Rapid industrial and technological development has impacted ecosystem homeostasis strongly. Arsenic is one of the most detrimental environmental toxins and its management with chelating agents remains a matter of concern due to associated adverse effects. Thus, safer and more effective alternative therapy is required to manage arsenic toxicity. Based on existing evidence, native and indigenous plant-based active biomolecules appear as a promising strategy to mitigate arsenic-induced toxicity with an acceptable safety profile. In this regard, various phytochemicals (flavonoids and stilbenoids) are considered important classes of polyphenolic compounds with antioxidant and chelation effects, which may facilitate the removal of arsenic from the body more effectively and safely with regard to conventional approaches. This review presents an overview of conventional chelating agents and the potential role of flavonoids and stilbenoids in ameliorating arsenic toxicity. This report may provide a roadmap for identifying novel prophylactic/therapeutic strategies for managing arsenic toxicity.     

A novel chrysin thiazole derivative polarizes macrophages to an M1 phenotype via targeting TLR4

Tumor-associated macrophages (TAMs) are an important cause of tumorigenesis and tumor development. M2 macrophages can promote tumor growth while M1 macrophages kill tumor cells, therefore, polarizing macrophages to achieve a functional M1 phenotype could effectively play its anti-tumor role. In the current study, we synthesized a novel chrysin derivative which is termed as ChR-TD. And we found ChR-TD might be a ligand of TLR4 that polarized the TAMs towards M1 phenotype and played its anti-tumor role. Further study indicated that ChR-TD reprogrammed the macrophages into an M1 phenotype via TLR4 activation. Moreover, ChR-TD activated TLR4/NF-κB signaling pathway and promoted the NF-κB/p65 translocated into the nuclear, leading to the activation of NF-κB and proinflammatory cytokines release. In addition, type I interferon signaling was also activated by ChR-TD, leading to the expressions of IFN-α and IFN-β and its targeted genes NOS2, MCP-1 and IP-10 were significantly increased in macrophages. Importantly, these effects were disturbed in TLR4^−/− macrophages, which are constructed by using CRISPR/Cas9 system. And the molecule docking simulation further indicated that ChR-TD could bind to TLR4 and might be a ligand of TLR4. Hence, these findings suggested that ChR-TD might be a ligand of TLR4 and can be used as a potential lead compound for tumors treatment.     

Assessment of ultra-structure,viability and function of lipopolysaccharides-stimulated human dermal fibroblasts treated with chrysin and exosomes (in vitro study)

BackgroundLipopolysaccharides (LPS) stimulate production of inflammatory cytokines. Chrysin is flavonoid beneficial for treatment of inflammatory conditions. Bone marrow mesenchymal stem cell (BM-MSC) exosomes have regenerative ability in different tissues.ObjectiveTo assess potential role of chrysin and BM-MSC exosomes on ultra-structure, viability and function of human dermal fibroblasts-adult (HDFa) stimulated by LPS.MethodsHDFa cells were divided into: Group I: Cells received no treatment. Group II: Cells were stimulated with LPS. Group III: LPS stimulated cells were treated with chrysin. Group IV: LPS stimulated cells were treated with exosomes.ResultsAfter 48 h, ultrastructural examination of HDFa cells in Group I revealed intact plasma membrane and numerous cytoplasmic organelles. Group II displayed destructed plasma membrane and apoptotic bodies. Group III showed intact plasma membrane with loss of its integrity at some areas. Group IV demonstrated intact plasma membrane that showed fusion with exosomes at some areas. Statistical analysis of MTT represented highest mean value of cell viability% in Group IV followed by Groups III, I and II respectively. Statistical analysis of enzyme-linked immunosorbent assay (ELISA) showed the highest mean value of interleukin-1β (IL-1β) was in Group II followed by Groups III, IV and I, while highest mean values of interleukin-10 (IL-10), nuclear factor-erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) proteins were in Group I, followed by Groups IV, III and II respectively.ConclusionsLPS have harmful consequences on ultra-structure, viability and function of HDFa cells. BM-MSC exosomes have better regenerative action on inflamed fibroblasts in comparison to chrysin.     

白杨黄素通过调控氧化应激反应保护脂多糖介导的炎症环境中人牙周膜干细胞的成骨分化能力

目的: 探讨白杨黄素对牙龈卟啉单胞菌(P.g)脂多糖(P.g LPS)介导的炎症环境中人牙周膜干细胞 (hPDLSCs)成骨分化能力的影响。方法：原代培养hPDLSCs, 采用流式细胞术鉴定后取第4代细胞进行实验。采用四唑盐(MTT)试验检测不同浓度P.g LPS (1, 10, 100 和1000 ng/mL)及白杨黄素 (0.1, 0.4, 1.6, 6.25, 25, 50, 100 μmol/L) 对hPDLSCs增殖能力的影响;P.g LPS与成骨诱导剂共培养24h, 48h, 72h和96h后,活性氧 (ROS)试剂盒检测hPDLSCs 的ROS含量, 实时荧光定量聚合酶链式反应 (RT-PCR)检测hPDLSCs锰超氧化物歧化酶(MnSOD), 铜锌超氧化物歧化酶(Cu/ZnSOD)和过氧化氢酶 (CAT) mRNA的表达; P.g LPS与成骨诱导剂共培养3天, 7天, 14天后, 碱性磷酸酶(ALP)试剂盒检测hPDLSCs 的ALP活性, RT-PCR法检测成骨相关转录因子(RUNX2), 锌指结构转录因子(OSX), 碱性磷酸酯酶(ALP) 和骨钙素(OCN) mRNA表达; 25 μmol/L 白杨黄素作用hPDLSCs后, 通过ROS试剂盒检测hPDLSCs 的ROS含量, 及实时PCR法检测抗氧化因子MnSOD、Cu/ZnSOD、CAT及成骨分化基因RUNX2、OSX、OCN和ALP的mRNA表达。结果：与对照组相比, MTT结果显示1000 ng/mL P.g LPS 作用hPDLSCs 72h [(0.51±0.03) 比 (0.68±0.02), 96h后(0.62±0.06) 比 (0.97±0.07), P均<0.05]均对细胞增殖活性受到显著抑制。并且25 μmol/L 的白杨黄素对hPDLSCs 增殖活性无抑制效应 [(99.8±1.02) 比 (100±1.02) %, P>0.05). 与常规成骨诱导液培养细胞相比, P.g LPS显著增加hPDLSCs的ROS含量至 (17.3±1.34) 比(3.12±1.21) ng/ml (P<0.01), 并显著降低抗氧化因子[Cu/ZnSOD, (0.89±0.24) 比 (2.84±0.27); CAT, (1.12±0.09) 比 (2.64±0.28), P均<0.05]和成骨分化基因表达 [ALP活性, (0.94±0.11) 比 (1.25±0.14); RUNX2, (1.42±0.13) 比 (1.97±0.16); OSX (1.97 ±0.16) 比 (2.68 ±0.19); OCN (1.23±0.11) 比 (2.56±0.17), P均<0.05]; 与P.g LPS+成骨诱导液组相比, 白杨黄素显著改善P.g LPS介导hPDLSCs的氧化状态及增强其成骨分化能力[RUNX2, (1.96±0.28) 比 (1.67±0.23); OSX (2.16±0.31) 比 (1.64±0.17), P均<0.05]。结论: 白杨黄素可能对P.g LPS介导的炎症环境中人牙周膜干细胞的成骨分化能力具有促进作用。     

Antiviral Activity of Chrysin Derivatives against Coxsackievirus B3 in vitro and in vivo

Chrysin is a 5,7-dihydroxyflavone and was recently shown to potently inhibit enterovirus 71 (EV71) by suppressing viral 3C protease (3C^pro) activity. In the current study, we investigated whether chrysin also shows antiviral activity against coxsackievirus B3 (CVB3), which belongs to the same genus (Enterovirus) as EV71, and assessed its ability to prevent the resulting acute pancreatitis and myocarditis. We found that chrysin showed antiviral activity against CVB3 at 10 μM, but exhibited mild cellular cytotoxicity at 50 μM, prompting us to synthesize derivatives of chrysin to increase the antiviral activity and reduce its cytotoxicity. Among four 4-substituted benzyl derivatives derived from C(5) benzyl-protected derivatives 7, 9–11 had significant antiviral activity and showed the most potent activity against CVB3 with low cytotoxicity in Vero cells. Intraperitoneal injection of CVB3 in BALB/c mice with 1×10⁶ TCID₅₀ (50% tissue culture infective dose) of CVB3 induced acute pancreatitis with ablation of acinar cells and increased serum CXCL1 levels, whereas the daily administration of 9 for 5 days significantly alleviated the pancreatic inflammation and reduced the elevation in serum CXCL1 levels. Collectively, we assessed the anti-CVB3 activities of chrysin and its derivatives, and found that among 4-substituted benzyl derivatives, 9 exhibited the highest activity against CVB3 in vivo, and protected mice from CVB3-induced pancreatic damage, simultaneously lowering serum CXCL1 levels.     

dFMAChR抑制荷人宫颈癌裸鼠移植瘤生长的机制研究

目的：研究6,8-二-三氟甲基-7-乙酰氧基白杨素（dFMAChR）抑制荷人宫颈癌裸鼠移植瘤生长的可能机制。方法：建立人宫颈癌裸鼠移植瘤模型,通过免疫组织化学SP染色法观察dFMAChR对人宫颈癌移植瘤组织血管内皮生长因子（VEGF）、细胞增殖核抗原（PCNA）表达的影响。结果：免疫组织化学检测发现dFMAChR抑制人宫颈癌移植瘤组织VEGF和PCNA的表达,且呈剂量依赖性。结论：dFAMChR能有效抑制人宫颈癌裸鼠移植瘤细胞PCNA和VEGF蛋白表达,这可能是dFMAChR抑制人宫颈癌裸鼠移植瘤生长的分子机制之一。     

白杨黄素影响两种胃癌细胞系增殖与凋亡的研究

目的研究白杨黄素对两种胃癌细胞系SGC-7901和MKN-45是否具有抑制作用的分子生物学机制。方法通过MTT法检测白杨黄素对SGC-7901和MKN-45细胞的增殖抑制作用，流式细胞术测定经白杨黄素处理后两种细胞的细胞周期，Westen-blot测定凋亡相关因子Caspase-3、Survivin和Bcl-2的表达水平。结果白杨黄素对SGC-7901和MKN-45细胞具有增殖抑制作用，呈时间浓度依赖性；能够将细胞周期阻滞于Sub G1期；能上调Caspase-3，下调Survivin和Bcl-2的基因表达。结论白杨黄素能够诱导SGC-7901和MKN-45细胞的凋亡并有效地抑制其增殖。其机制可能与干扰细胞周期及激活Caspase-3，抑制Survivin和Bcl-2有关。     

活性氧生成在8-硝基白杨素诱导人胃癌SGC-7901细胞凋亡中的作用

目的研究活性氧生成在8-硝基白杨素(NOC)诱导人胃癌SGC-7901细胞凋亡中的作用。方法体外培养SGC-7901细胞,采用流式细胞术分析细胞凋亡率,ELISA法检测细胞组蛋白/DNA碎片,H2DCFH-DA探针流式细胞仪检测细胞活性氧(ROS)生成。结果 NOC诱导亚G1峰(Sub-G1)细胞百分率增高和细胞组蛋白/DNA碎片增加(P<0.01),促进SGC-7901细胞活性氧生成(P<0.01)。抗氧化剂N-乙酰半胱氨酸(NAC)能有效对抗NOC诱导SGC-7901细胞凋亡作用。结论 NOC诱导SGC-7901细胞凋亡作用与促进活性氧生成相关。     

8-硝基白杨素对人宫颈癌Hela细胞增殖和凋亡的影响

目的：观察8-硝基白杨素(8-NOChR)抑制体外培养人宫颈癌Hela细胞增殖和诱导凋亡作用。方法：体外培养人宫颈癌Hela细胞系细胞。MTT比色法测定Hela细胞增殖活性。软琼脂培养克隆形成法检测Hela细胞集落形成能力。AO/EB染色荧光显微镜观察Hela细胞凋亡形态学改变。DNA凝胶电泳观察梯形DNA条带。结果：MTT比色测定显示，8-NOChR抑制Hela细胞增殖，呈剂量依赖性。软琼脂培养克隆形成法检测表明，8-NOChR显著抑制Hela细胞集落形成，呈剂量依赖性。AO/EB染色荧光显微镜观察发现，8-NOChR诱导Hela细胞呈现典型凋亡细胞形态特征。8-NOChR（30μmol/L）处理Hela细胞72h，琼脂糖凝胶电泳出现“梯形”DNA条带。结论：8-NOChR具有抑制人宫颈癌Hela细胞增殖和诱导细胞凋亡作用