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.     

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     

白杨素和它的四乙基二磷酸酯对人宫颈癌 Hela细胞增殖和核基质蛋白影响的研究

探讨白杨素和它的四乙基二磷酸酯对人宫颈癌细胞的增殖、分化和核基质蛋白的影响。用终浓度为10μmol/L的白杨素(chrysin,CR)和四乙基白杨素二磷酸酯(tetraethyl bis-phosphoric ester of chrysin,CP)分别处理人人宫颈癌Hela细胞,记录细胞生长数目,进行增殖分化型细胞染色,测定软琼脂集落形成率,应用SDS-PAGE技术分析细胞核基质蛋白成分的变化。CR/CP能明显抑制Hela细胞的增殖,处理组与对照组之间差异有显著性(P<0.05);处理组与对照组比较增殖型细胞减少,分化型细胞数增加,双层软琼脂中细胞集落形成受到明显抑制,对照组集落普遍比药物组集落大,且单个集落中细胞数目多(P<0.05);通过Quantity One软件分析,实验组(CR组与CP组)与对照组(C组)比较,相对分子质量70 0006、8 000、13 000为增加的条带,14 000、17 000、18 000为增强的条带,58 000、43 000是减弱的条带。两实验组相比,以CP组变化显著。CR和CP对Hela细胞具有增殖抑制和诱导分化作用。同时还可以诱导Hela细胞核基质蛋白成分改变,这可能对肿瘤细胞基因表达调控、分化及凋亡起重要作用。     

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.     

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.     

6,8-二-三氟甲基-7-乙酰基白杨素抗肝癌作用实验研究

目的:研究6,8-二-三氟甲基-7-乙酰基白杨素(dFMAChR)体内外抗肝癌作用。方法:MTT比色法测定dFMAChR对体外培养人肝癌细胞Hep G2细胞和人胚肝细胞L-02细胞增殖的影响;平皿克隆形成法及软琼脂克隆形成法测定dFMAChR对体外培养Hep G2细胞的锚定依赖性及非锚定依赖性生长作用;PI染色流式细胞术(FCM)分析dFMAChR对Hep G2细胞周期的影响;人肝癌裸鼠异种移植瘤模型治疗实验评价dFMAChR治疗人肝癌的有效性。结果:dFMAChR抑制体外培养人肝癌Hep G2细胞增殖和生长,其效价强度高于先导化合物白杨素(ChR),而对人胚肝(L-02)细胞的毒性小,其选择指数为42.96。PI染色FCM结果显示3.0μM,10.0μM,30.0μM的dFMAChR作用于Hep G2细胞48h后,其G1期累积细胞百分率分别为64.5%、69.1%、78.4%,较溶媒对照组和ChR 30.0μM的58.2%和68.3%有显著提高,呈现G1期阻滞现象。人肝癌裸鼠异种移植瘤模型治疗实验结果显示:dFMAChR对人肝癌异种移植瘤生长具有显著抑制作用,20,40,80 mg/kg的dFMAChR对移植瘤的瘤重抑制率分别为40.17%,47.41%和66.81%。结论:dFMAChR具有人肝癌治疗作用。     

6,8-二-三氟甲基-7-乙酰氧基白杨素抑制酪蛋白激酶诱导人卵巢癌CoC1细胞凋亡

目的:研究6,8-二-三氟甲基-7-乙酰氧基白杨素(9dFMAChR))抑制体外培养人卵巢癌细胞系CoC1细胞增殖和诱导凋亡作用及机制。方法:体外培养CoC1细胞,MTT比色法测定dFMAChR对CoC1细胞增殖活性的影响;AO/EB染色法荧光显微镜观察dFMAChR诱导CoC1凋亡细胞的形态学改变;DNA凝胶电泳确证dFMAChR诱导CoC1细胞凋亡作用;Western blotting法分析dFMAChR对CoC1细胞酪蛋白激酶CK2α蛋白表达和活性的影响。结果:MTT比色法结果显示,dFMAChR有效抑制CoC1细胞增殖活性,呈剂量依赖性;其IC50值为11.8μM。AO/EB染色荧光显微镜观察dFMAChR处理后,部分CoC1细胞呈现典型凋亡细胞形态特征;dFMAChR(10.0μM)处理CoC1细胞48 h,琼脂糖凝胶电泳出现“梯形”DNA条带。Western blotting分析结果表明:dFMAChR下调酪蛋白激酶CK2α表达,呈浓度和时间依赖性。结论:dFMAChR具有抑制人卵巢癌CoC1细胞增殖和诱导细胞凋亡作用;作用机制与其抑制酪蛋白激酶CK2α表达有关。     

Chrysin promotes tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) induced apoptosis in human cancer cell lines

Chrysin exists widely in plants, honey and propolis. The anti-cancer property of chrysin has been demonstrated though the molecular mechanism is not clear. In this study, we found that pre-treatment with chrysin could promote the cell death induced by TRAIL according to the morphological changes and appearance of sub-G1 peak in four human cancer cell lines. In HCT-116 cells, the results of flow cytometry analysis showed that the percentage of sub-G1 reached (38.89 ± 3.78) % when pre-treatment of chrysin was used at 40 μM, but that was only (2.53 ± 0.10) % in the untreated group and (13.22 ± 0.20) % in TRAIL alone group. The differences between the combination and the untreated or TRAIL alone group were all significant (P < 0.05) and dose-dependent effect was obvious. Similar results were obtained in CNE1 cells. In the search of molecular mechanisms, we found that pre-treatment with chrysin could increase TRAIL-induced degradation of caspase 3, caspase 8, PARP proteins. Z-VAD-fmk, which is a pan-caspase inhibitor, could inhibit the apoptosis enhanced by the combination of chrysin and TRAIL. All data indicate that chrysin can enhance the apoptosis induced by TRAIL, and the apoptosis is caspase-dependent and related to the activation of caspase 8.     

HPLC法测定紫果西番莲叶中白杨素的含量

目的:建立测定紫果西番莲叶中白杨素含量的方法。方法:样品经硅胶柱色谱分离纯化后进行高效液相色谱分析。色谱柱为HypersilODSC18(250mm×4.6mm,5μm),流动相为乙腈-0.1磷酸(18:82),流速为1.0mL.min-1,检测波长为220nm,进样量为10μL。结果:白杨素进样浓度在0.012～0.120mg.mL-1范围内与峰面积积分值呈良好线性关系(r=0.9980);平均加样回收率为99.41%,RSD=1.6%(n=6)。结论:该方法准确、可靠、重复性好,可用于西番莲属植物中白杨素含量的测定。     

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。