Induction of apoptosis of human gastric carcinoma SGC-7901 cell line by 5,7-dihydroxy-8-nitrochrysin in vitro

AIM： To investigate the effect of 5, 7-dihydroxy-8- nitrochrysin （NOChR） on apoptosis of human gastric carcinoma SGC-7901 cell line.METHODS： SGC-7901 cells were cultured in vitro and the inhibitory effect of NOChR on proliferation of SGC-7901 cells was measured by using an Ml-r assay. NOChR-induced apoptosis rate of SGC-7901 cells was detected using flow cytometry （FCM） with PI staining. DNA ladder bands were observed by DNA agarose gel electrophoresis. The influence of NOChR on the proxisome proliferator-activated receptor-γ （PPARγ）, Bcl-2 and Bax protein expression of SGC-7901 cells was analyzed by Western blot.RESULTS： MIF assay showed that NOChR markedly inhibited proliferation of SGC-7901 cells in a dose- dependent manner, and when ICso was 4.14 μmol/L, the potency of NOChR was 10 times than that of lead compound, chrysin （ChR, IC50 was 40.56 μmol/L）, and was similar to 5-fluorouracil （5-FU, IC50 was 4.51 μmol/L）. FCM with propidium iodide （PI） staining demonstrated that the apoptosis rates of SGC-7901 cells treated with 1.25, 5.00 and 20.00 μmol/L NOChR for 48 h were 9.8% 4- 0.2%, 36.8% 4- 1.9% and 45.5% 4- 3.5%, respectively, and were significantly higher when treated with 5.00 and 20.00 μmol/L NOChR than that with 20.00 μmol/L ChR （12.9% 4- 1.5%）. DNA agarose gel electrophoresis showed that treatment of SGC-7901 cells with 20.00 μmol/L NOChR for 48 h resulted in typical DNA ladder bands of DNA of SGC-7901 cells, which could be eliminated by treating with 10.00 μmol/L GW9662, a blocker of PPARy. Western blot analysis revealed that after 24 h of treatment with 20.00 μmol/L NOChR, PPARgamma and Bax protein expression of SGC-7901 cells increased but Bcl-2 expression decreased; however, pre-incubation with 10.00 μmol/L GW9662 could efficiently antagonize and weaken the regulatory effect of 20.00 μmol/L NOChR on Bax and Bcl-2 protein expression of SGC-7901 cells. CONCLUSION： NOChR induces apoptosis of SGO7901 cell lines by activating PPARy and decreasing ratio of Bcl-2 to Bax.

Induction of apoptosis in human liver carcinoma HepG2 cell line by 5-allyl-7-gen-difluoromethylenechrysin

AIM： To investigate the effect of 5-allyl-7-gen-difluoromethylenechrysin （ADFMChR） on apoptosis of human liver carcinoma HepG2 cell line and the molecular mechanisms involved.METHODS： HepG2 cells and L-02 cells were cultured in vitro and the inhibitory effect of ADFMChR on their proliferation was measured by MTT assay. The apoptosis of HepG2 cells was determined by flow cytometry （FCM） using propidium iodide （PI） fluorescence staining. DNA ladder bands were observed by DNA agarose gel electrophoresis. The influence of ADFMChR on the proxisome proliferator-activated receptor γ （PPARγ）, NF-κB, Bcl-2 and Bax protein expression of HepG2 cells were analyzed by Western blotting.RESULTS： MTT assay showed that ADFMChR significantly inhibited proliferation of HepG2 cells in a dose- dependent manner, with little effect on growth of L-02 cells, and when ICs0 was measured as 8.45 μmol/L and 191.55 μmol/L respectively, the potency of ADFMChR to HepG2 cells, was found to be similar to 5-fluorouracil （5-FU, ICso was 9.27 μmol/L）. The selective index of ADFMChR cytotoxicity to HepG2 cells was 22.67 （191.55/8.45）, higher than 5-FU （SI was 7.05 （65.37/9.27）. FCM with PI staining demonstrated that the apoptosis rates of HepG2 cells treated with 3.0, 10.0 and 30.0 μmol/L ADFMChR for 48 h were 5.79%, 9.29% and 37.8%, respectively, and were significantly higher when treated with 30.0 μmol/L ADFMChR than when treated with 30.0 μmol/L ChR （16.0%） （P 〈 0.05） and were similar to those obtained with 30.0 μmol/L 5-FU（41.0%）. DNA agarose gel electrophoresis showed that treatment of HepG2 cells with 10.0 μmol/L ADFMChR for 48 h and 72 h resulted in typical DNA ladders which could be reversed by 10.00 pmol/1 GW9662, a blocker of PPARy. Western blotting analysis revealed that aEer 24 h of treatment with 3.0, 10.0, 30.0 μmol/L ADFMChR, PPARy and Bax protein expression in HepG2 cells increased but Bcl-2 and NF-κB expression decreased; however, pre-incubation with 10.0 μmol/L GW9662 could efficiently antagonize and weaken the regulatory effect of 3.0, 30.0 μmol/L ADFMChR on PPARy and NF-KB protein expression in HepG2 cells.CONCLUSION： ADFMChR induces apoptosis of HepG2 cell lines by activating PPARγ, inhibiting protein expression of Bcl-2 and NF-κB, and increasing Bax expression.

A Convenient Synthesis of Chrysin and Tectochrysin

Chrysin(1) and tectochrysin(2) were respectively synthesized in four steps from 1,3,5-tribromobenzene in an overall yield of 46.8% and that of 37.0% with the key step being the Bu_4NBr catalyzed hydrolysis of 1-phenyl-3-(2′,4′,6′-trimethoxyphenyl)-1, 3-propanedione (11) under different conditions.

8-bromo-7-methoxychrysin-induced apoptosis of hepatocellular carcinoma cells involves ROS and JNK

AIM:To investigate whether the apoptotic activities of 8-bromo-7-methoxychrysin(BrMC) involve reactive oxygen species(ROS) generation and c-Jun N-terminal kinase(JNK) activation in human hepatocellular carcinoma cells(HCC).METHODS:HepG2,Bel-7402 and L-02 cell lines were cultured in vitro and the apoptotic effects of BrMC were evaluated by flow cytometry(FCM) after propidium iodide(PI) staining,caspase-3 activity using enzymelinked immunosorbent assay(ELISA),and DNA agarose gel electrophoresis.ROS production was evaluated by FCM after dichlorodihydrofluorescein diacetate(DCHFDA) probe labeling.The phosphorylation level of JNK and c-Jun protein was analyzed by Western blotting.RESULTS:FCM after PI staining showed a dose-dependent increase in the percentage of the sub-G1 cell pop-ulation(P < 0.05),reaching 39.0% ± 2.8% of HepG2 cells after 48 h of treatment with BrMC at 10 μmol/L.The potency of BrMC to HepG2 and Bel-7402(32.1% ± 2.6%) cells was found to be more effective than the lead compound,chrysin(16.2% ± 1.6% for HepG2 cells and 11.0% ± 1.3% for Bel-7402 cell) at 40 μmol/L and similar to 5-flurouracil(33.0% ± 2.1% for HepG2 cells and 29.3% ± 2.3% for Bel-7402 cells) at 10 μmol/L.BrMC had little effect on human embryo liver L-02 cells,with the percentage of sub-G1 cell population 5.4% ± 1.8%.Treatment of HepG2 cells with BrMC for 48 h also increased the levels of active caspase-3,in a concentration-dependent manner.z-DEVD-fmk,a caspase-3specific inhibitor,prevented the activation of caspase-3.Treatment with BrMC at 10 μmol/L for 48 h resulted in the formation of a DNA ladder.Treatment of cells with BrMC(10 μmol/L) increased mean fluorescence intensity of DCHF-DA in HepG2 cells from 7.2 ± 1.12 at 0 h to 79.8 ± 3.9 at 3 h and 89.7 ± 4.7 at 6 h.BrMC did not affect ROS generation in L-02 cells.BrMC treatment failed to induce cell death and caspase-3 activation in HepG2 cells pretreated with N-acetylcysteine(10 mmol/L).In addition,in HepG2 cells treated with BrMC(2.5,5.0,10.0 μmol/L) for 12 h,JNK activation was observed.Peak JNK activation occurred at 12 h post-treatment and this activation persisted for up to 24 h.The expression of phosphorylated JNK and c-Jun protein after 12 h with BrMC-treated cells was inhibited by N-acetylcysteine and SP600125 pre-treatment,but GW9662 had no effect.SP600125 substantially reduced BrMC-induced cell death and caspase-3 activation of HepG2 cells.N-acetylcysteine and GW9662 also attenuated induction of cell death and caspase-3 activation in HepG2 cells treated with BrMC.CONCLUSION:BrMC induces apoptosis of HCC cells by ROS generation and sustained JNK activation.

Synthesis and Anticancer Effect of gem-Difluoromethylenated Chrysin Derivatives

Ten gem-difluoromethylenated chrysin derivatives were prepared and their anticancer activities in vitro were evaluated by the standard MTT method. The results of biological test showed that some of gem-difluoromethylenated chrysin derivatives had higher anticancer activity than chrysin.

Design,synthesis,and biological evaluation of novel chrysin derivatives as poly(ADP-ribose)polymerase 1(PARP1)inhibitors for the treatment of breast cancer

In this study,we reported the discovery and structure-activity relationship analysis of chrysin derivatives as a new class of inhibitors targeting poly(ADP-ribose)polymerase 1(PARP1).Among these derivatives,compound 5d emerged as the most effective chrysin-based inhibitor of PARP1,with an IC50 value of 108 nmol·L^(-1).This compound significantly inhibited the proliferation and migration of breast cancer cell lines HCC-1937 and MDA-MB-436 by inducing DNA damage.Furthermore,5d induced apoptosis and caused an extended G1/S-phase in these cell lines.Molecular docking studies revealed that 5d possesses a strong binding affinity toward PARP1.In vivo,in a xenograft model,5d effectively reduced tumor growth by downregulating PARP1 expression.Overall,compound 5d shows promise as a potential therapeutic agent for the treatment of BRCA wild-type breast cancer.

白杨素减轻非酒精性脂肪性肝炎小鼠脂肪变性及血脂异常

目的:探究白杨素对非酒精性脂肪性肝炎(NASH)的治疗作用。方法:将8周龄C57BL/6雄性小鼠随机分为对照组、模型组和白杨素组。除对照组给予普通饲料外,其余各组给予蛋氨酸胆碱缺乏(MCD)饲料喂养。造模5周后灌胃,白杨素组给予白杨素(20 mg/kg),对照组和模型组给予同体积生理盐水,连续给药6周。实验期间观察小鼠状态;处死后观察小鼠肝脏形态;检测体质量和肝脏湿重;用生化分析仪检测血清中甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)含量、丙氨酸转氨酶(ALT)和天冬氨酸转氨酶(AST)水平;用试剂盒检测肝脏组织中TG和TC含量;采用苏木素-伊红(HE)染色和F4/80免疫组化染色探究白杨素对NASH中肝细胞损伤和炎症的影响;用油红O染色探究肝脏脂质沉积的程度;Masson和天狼星红染色检测肝纤维化;免疫组化法检测纤维化相关分子的表达水平。结果:与对照组比较,模型组小鼠体重和肝脏湿重明显下降,肝脏体积减小,呈黄色,可见黄色脂肪斑,边缘钝;血清TG、LDL-C、ALT和AST水平,以及肝组织TG和TC水平显著升高,HDL-C水平降低;病理染色结果显示有明显的炎症细胞浸润、脂质沉积及肝脏纤维化。与模型组相比,白杨素组小鼠体重和肝重均有升高,肝脏红润,表面相对光滑,肝缘锐利;血清TG、LDL-C、AST和ALT水平,以及肝组织TG水平显著降低;白杨素可抑制炎症细胞浸润、脂质沉积及肝组织纤维化。结论:白杨素可抑制肝脏脂肪变性、炎症及纤维化,有潜力成为治疗NASH的候选药物。

白杨素脂质体的制备工艺优化及抗神经炎症活性研究

目的 优化白杨素脂质体的制备工艺并研究其体外抗神经炎症活性。方法 采用乙醇注入法制备白杨素脂质体,根据单因素实验结果,通过Box-Behnken响应面筛选最优处方并表征。细胞毒性实验确定白杨素及其脂质体的安全药物浓度范围,利用脂多糖(LPS)诱导的BV2细胞分析白杨素脂质体的抗神经炎症活性。结果 白杨素脂质体最佳制备工艺参数:磷脂与胆固醇比7.86∶1、搅拌速度615 r·min^(-1)、水浴温度60℃,制备的白杨素脂质体形态呈椭圆球形,包封率为(85.01±0.33)%,平均粒径为(141.43±0.5)nm,平均PDI为(0.240±0.021),体外释药具有明显的缓释特征。细胞实验结果显示,在0~100μmol·L^(-1)实验浓度范围内,空白脂质体对BV2细胞无明显的细胞毒性。抗炎性能分析表明,相较于游离白杨素,白杨素脂质体对LPS诱导的BV2细胞具有更强的抗炎效果,且在使用范围(<25μmol·L^(-1))内无细胞毒性。结论 本研究成功制备并优化了白杨素脂质体,该制剂提高了白杨素的溶解度和体外释放性能,同时展现出良好的体外抗炎活性,为未来白杨素新剂型的开发提供了理论基础。

Chrysin promotes osteogenic differentiation via ERK/MAPK activation

T he effect of the anti-infl ammatory fl avonoid chrysin on osteogenesis was determined in preosteoblast MC3T3-E1 cells.Results demonstrated that chrysin could induce osteogenic differentiation in the absence of other osteo-genic agents.Chrysin treatment promoted the expres-sion of transcription factors(Runx2 and Osx)and bone formation marker genes(Col1A1,OCN,and OPN)as well as enhanced the formation of mineralized nodules.During osteogenic differentiation,chrysin preferentially activated ERK1/2,but not JNK nor the p38 MAPKs.Further experi-ments with inhibitors revealed the co-treatment of U0126,PD98059,or ICI182780(a general ER antagonist)with chrysin effectively abrogated the chrysin-induced osteo-genesis and ERK1/2 activation.Thus,the effect of chrysin on osteogenesis is ERK1/2-dependent and involves ER.Therefore,chrysin has the signifi cant potential to enhance osteogenesis for osteoporosis prevention and treatment.

基于网络药理学和分子对接探究白杨素和柚皮素抗PEDV的作用机制及试验验证

【目的】探讨白杨素和柚皮素抗猪流行性腹泻病毒(Porcine epidemic diarrhea virus,PEDV)的作用靶点和机制,为进一步以白杨素和柚皮素开发新型抗PEDV的治疗药物提供理论依据。【方法】利用PharmMapper、TCMSP、SEA Search Server和STITCH在线数据库获得白杨素和柚皮素的潜在作用靶点,同时检索GeneCards数据库获得PEDV对宿主的作用靶点,利用在线程序Draw Venny Diagram获取白杨素、柚皮素与疾病的交集靶点。通过STRING数据库和Cytoscape 3.9.1软件构建靶蛋白互作(PPI)网络并筛选关键靶点,对靶点进行GO功能和KEGG通路富集分析。通过AutoDock Vina v 1.2.0软件对核心靶点及小分子进行分子对接,并分析白杨素和柚皮素与靶蛋白的结合能和结合模式,利用PyMOL v 2.5实现对接结果的可视化。采用实时荧光定量PCR和Western blotting检测白杨素和柚皮素对核心靶蛋白表达的影响。【结果】白杨素潜在抗PEDV的靶点有12个,其中白蛋白(ALB)、雌激素受体1(ESR1)、转化生长因子β-1蛋白(TGF-β1)可能是白杨素抗PEDV的核心靶点;柚皮素潜在抗PEDV的靶点有18个,其中ALB、胱天蛋白酶3(Caspase-3,CASP3)、过氧化物酶体增殖物激活受体γ(PPARG)可能是柚皮素抗PEDV的核心靶点。白杨素抗PEDV靶点涉及21种生物过程、5种细胞组分和6种分子功能,共获得11条信号通路;柚皮素抗PEDV靶点涉及31种生物过程、8种细胞组分和19种分子功能,共获得13条信号通路。核心靶点与两种天然化合物之间以氢键和疏水作用力为主,有较强的相互作用。白杨素和柚皮素能极显著降低Caspase-3表达量(P<0.01),可能通过影响Caspase-3的表达和活化来颉颃PEDV诱导的细胞凋亡;极显著升高TGF-β1蛋白表达量(P<0.01),可能通过影响TGF-β1的表达抗PEDV诱导的炎症反应而治疗PEDV的感染。【结论】本研究揭示了白杨素和柚皮素分别通过潜在核心靶点ALB、ESR1、TGF-β1和ALB、Caspase-3、PPARG,以及IL17、PI3K-Akt和AMPK信号通路发挥抗PEDV作用的机制,为新型抗PEDV药物的研发提供新的思路。

7-羟乙基白杨素聚乳酸-羟基乙酸共聚物纳米粒的制备及体外释放评价

目的:制备和评价7-羟乙基白杨素(7-HEC)聚乳酸-羟基乙酸共聚物(PLGA)纳米粒。方法:采用乳化溶剂挥发法制备7-HEC/PLGA纳米粒,以粒径、多分散系数(PDI)、包封率、载药量及Zeta电位为评价指标,通过单因素考察结合Box-Behnken响应面法优化处方。采用甘露醇作为冻干保护剂制备冻干粉,对最优处方制备的7-HEC/PLGA纳米粒进行表征及体外释放研究。结果:经Box-Behnken响应面法优化后的最优处方为:药载比2.12∶20,油水体积比1∶14.7,乳化剂为2.72%大豆磷脂。最优处方条件制备的7-HEC/PLGA纳米粒的平均粒径为(240.28±0.96)nm、PDI为0.25±0.69、包封率为(75.74±0.80)%、载药量为(6.98±0.83)%、电位为(-18.17±0.17)mV。体外释放48 h内累积释放度达到50%以上。结论:优化所得处方工艺稳定、操作简便。所得7-HEC/PLGA纳米粒粒度均匀,包封率较高。相对于7-HEC原料药,7-HEC/PLGA纳米粒的溶出度显著提高。

Investigation on Electrochemical Behavior and Scavenging Superoxide Anion Ability of Chrysin at Mercury Electrode

The electrochemical behavior of chrysin in pH 2.0-9.0 Britton-Robinson （B-R） buffer solutions was studied by the means of linear sweep voltammetry and cyclic voltammetry at a static mercury drop electrode. In different pH range of B-R buffer solutions, chrysin could cause four reduction waves. In pH 2.0-5.8 B-R buffer solutions, wave P1 yielded by chrysin is a one-electron reduction wave, and wave P1 caused by further reduction of the products of wave P1 in pH〈3.0 B-R buffer solution is also a one-electron reduction wave. But in 3.0〈pH〈5.8 B-R buffer solution wave P1 was overlapped by the hydrogen wave. Between pH 5.8 and 9.0, chrysin could yield two reduction waves P2 and P3- The former is an irreversible adsorptive wave of ionized chrysin involving one electron and the latter is also an irreversible adsorptive wave of reduction intermediate radical of chrysin involving one electron and one proton. And a linear relationship between ip3 and the concentration of chrysin can be established from 1.0×10^-6 to 4.0×10^-5 mol·L^-1 （r=0.9924） with the detection limit of 5×10^-7 mol·L^-1. In addition, the antioxidant ability of chrysin was investigated by linear sweep voltammetry （LSV）. The determination result of IC50 of chrysin showed that chrysin is a good antioxidant.

Effects of Inclusion of Chrysin in Cucurbit[8]uril on Its Stability, Solubility and Antioxidant Potential

The host-guest interaction between cucurbit[8]uril（Q[8]） and chrysin（CHR） has been studied by means of 1H NMR, mass spectrometry（MS）, differential thermal analysis（DTA）, and UV-Vis spectrophotometry. The results show that CHR forms a 1：1 inclusion complex with Q[8], with a binding constant of CHR with Q[8] by UV absorp- tion being 5.4 × 106. Phase solubility experiments show a 5.13-fold increase in the solubility of CHR through interac- tion with Q[8] {c（Q[8]）=10-4 real/L}. A study of the evolution of UV absorption spectra with time shows that Q[8] significantly increases the stability of CHR. The antioxidant activity of CHR-Q[8] has been tested by the ABTS me- thod. The CHR-Q[8] inclusion complex shows a better scavenging effect towards the ABTS radical than CHR, with respective IC50 values of 1.05 ×10-6 and 3.07× 10-6 mol/L. In vitro release studies have shown that CHR-Q[8] has a sustained release effcct.

Chrysin serves as a novel inhibitor of DGKα/FAK interaction to suppress the malignancy of esophageal squamous cell carcinoma(ESCC)

Among current novel druggable targets,proteineprotein interactions(PPIs)are of considerable and growing interest.Diacylglycerol kinase a(DGKα)interacts with focal adhesion kinase(FAK)band 4.1-ezrin-radixin-moesin(FERM)domain to induce the phosphorylation of FAK Tyr397 site and promotes the malignant progression of esophageal squamous cell carcinoma(ESCC)cells.Chrysin is a multi-functional bioactive flavonoid,and possesses potential anticancer activity,whereas little is known about the anticancer activity and exact molecular mechanisms of chrysin in ESCC treatment.In this study,we found that chrysin significantly disrupted the DGKα/FAK signalosome to inhibit FAKcontrolled signaling pathways and the malignant progression of ESCC cells both in vitro and in vivo,whereas produced no toxicity to the normal cells.Molecular validation specifically demonstrated that Asp435 site in the catalytic domain of DGKαcontributed to chrysin-mediated inhibition of the assembly of DGKα/FAK complex.This study has illustrated DGKα/FAK complex as a target of chrysin for the first time,and provided a direction for the development of natural products-derived PPIs inhibitors in tumor treatment.

Preventive effect of chrysin on experimental autoimmune uveitis triggered by injection of human IRBP peptide 1-20 in mice

Uveitis is a common cause of blindness worldwide.Experimental autoimmune uveitis(EAU)is an animal model of noninfectious uveitis.Chrysin(5,7-dihydroxyflavone)is a member of the flavonoid family and has anti-inflammatory effects.We immunized C57BL/6J mice with human interphotoreceptor retinoid-binding protein peptide 1–20 to induce EAU.Chrysin was administered intragastrically at 25 mg/kg daily to the chrysin-treated mice from 3 days before immunization to 21 days after immunization.Vehicle was administered to the mice in the control group according to the same protocol.Lower clinical and histopathological scores,increased integrity of the blood–retinal barrier(BRB)and higher expression of tight junction proteins were observed in the chrysin-treated mice.Chrysin significantly decreased the proportions of Th1,Th17 and CD4^(+)CD3^(+)CD62L^(+)Th0 cells,and increased the proportion of Treg cells.Both macrophage infiltration and the expression of inducible nitric oxide synthase in the retina were efficiently inhibited by chrysin treatment.In chrysin-treated mice,the expression of interferon-γ,interleukin(IL)-17A,IL-6,IL-1βand tumor necrosis factor-αwas reduced in the retina,whereas higher levels of transforming growth factor-βwere detected.Furthermore,NF-κBp65 was downregulated after chrysin treatment.In conclusion,as an anti-inflammatory molecule,chrysin exerts a preventive effect on EAU by modulating the balance among helper T-cell subsets and suppressing ocular inflammation,thereby maintaining the integrity of the BRB.

Synthesis of New 7-O-Modified Chrysin Derivatives and Their Anti-proliferative and Apoptotic Effects on Human Gastric Carcinoma MGC-803 Cells

Two series of 7-O-modified chrysin derivatives were prepared from 7-O-carboxymethy! chrysin（2a）, 7-O-carboxypropylchrysin（2b） and short-chain alcohols by using 1-ethyl-3-（3-dimethylaminopropyl）carbodiimide hydrochloride（EDCI）, N-hydroxybenzotriazole（HOBt） and 4-dimethylamiopryidine（DMAP） as coupling reagents. Taking cisplatin as a reference substance, their anti-proliferative activities in vitro against human gastric carcinoma MGC-803 cells were evaluated by the standard 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl-2H-tetrazolium bromide （MTT） method. The results show that among the compounds tested, hepty 4-（5-hydroxy-4-oxo-2-phenyl-4H- chromen-7-yloxy） acetate（3f） displayed the most potent growth-inhibitory effect on MGC-803 cells with half maximal inhibitory concentration（ICso） value of 3.23 pmol/L. The preliminary mechanism of inhibitory effect of compound 3f was also detected by flow cytometry（FCM）, and the compound exerted anti- cancer activity via inducing the apoptosis of MGC-803 cells in a dose dependent manner, which suggested that compound 3f would be a potential anti-cancer agent.

多光谱法结合分子对接探究4种黄酮与β-乳球蛋白的相互作用

目的 探究4种黄酮[柚皮苷(naringin,Nar)、黄芩素(baicalein,Bai)、白杨素(chrysin,Chr)和漆黄素(fisetin,Fis)]与β-乳球蛋白(β-lactoglobulin,β-Lg)的相互作用。方法 首先采用分子对接技术模拟预测4种黄酮与β-Lg的结合位点,再利用荧光光谱法研究4种黄酮与β-Lg的荧光猝灭作用及作用机制,并计算相关参数,最后通过多种光谱法分析4种黄酮对β-Lg空间构象的变化。结果 分子对接结果 表明Nar和Fis结合在β-Lg的疏水空腔口处,Bai与Chr与β-Lg的结合位点在β-Lg的外表面。荧光光谱结果 表明,4种黄酮对β-Lg均产生静态猝灭,结合常数均在104~107数量级,说明Nar/Bai/Chr/Fis均与β-Lg结合紧密且形成稳定的复合物;热力学参数分析表明Nar/Bai/Chr/Fis与β-Lg的结合为自发进行,其中Nar/Bai与β-Lg作用力类型是氢键和范德华力, Chr/Fis与β-Lg是疏水相互作用。同步荧光光谱、三维荧光光谱、紫外-可见光吸收光谱和傅里叶变换红外光谱结果 表明,Nar/Bai/Chr/Fis与β-Lg发生相互作用后使β-Lg的空间构象发生变化。结论 4种黄酮均能与β-Lg结合,为黄酮类化合物与生物大分子作用机制研究及对活性成分的保护和利用提供理论支持。

白杨素通过促进氧化应激介导的AKT/mTOR通路失活诱导肺癌细胞发生自噬

目的研究白杨素(Chrysin,CHR,5,7-二羟基黄酮)通过AKT/mTOR通路在肺癌细胞中诱导自噬的机制。方法培养肺癌细胞A549及PC9并通过行细胞活力实验、克隆形成实验检测白杨素对肺癌细胞增殖能力的影响;通过行透射电镜、免疫荧光实验、蛋白质印记、活性氧实验等探究AKT/mTOR通路在肺癌细胞中诱导自噬的机制。结果1.细胞增殖实验、克隆形成实验结果表明,白杨素可以以时间浓度依赖性的方式抑制肺癌细胞增殖。2.透射电镜的结果显示,白杨素能够增加肺癌细胞中自噬小体和自噬溶酶体数量。3.免疫荧光的实验结果表明,在白杨素作用后的肺癌细胞中,检测到LC3Ⅱ的细胞内定位和丰富的LC3Ⅱ斑点,而对照组细胞没有表现出明显的荧光强度。4.一定浓度的白杨素上调了肺癌细胞中LC3Ⅱ和Beclin 1蛋白的表达,下调了P62蛋白的表达。联合使用氯喹(CQ)后,LC3Ⅱ的表达进一步升高。5.细胞增殖实验结果表明,在加入氯喹后,白杨素对肺癌细胞增殖的抑制的能力进一步增强。6.白杨素可以促进肺癌细胞活性氧(ROS)集聚,在加入N-乙酰-L-半胱氨酸(NAC)后,LC3Ⅱ的表达下调。7.白杨素抑制了AKT/mTOR通路相关蛋白的表达,在加入NAC后,通路相关蛋白的表达升高。结论在肺癌中,活性氧介导的AKT/mTOR通路的失活参与了白杨素诱导的自噬,自噬抑制剂可以进一步增强白杨素的抗癌效果。

Synthesis and anti-tumor activities of novel 7-O-amino acids chrysinderivatives

Objective: To design and synthesize a series of chrysin derivatives and evaluate the antitumor activities with MTT assay, so as to investigate molecular structure-activity relationship with molecular docking.Methods: Target products were synthesized with high yield by substitution reaction, hydrolysis reaction,esterification reaction, and saponification reaction in sequence, and activities of all compounds were evaluated with human gastric carcinoma cell lines MGC-803 and human breast carcinoma cell lines MCF-7 through standard MTT assay. Molecular docking results were calculated with Surflex Geom X programme of Sybyl X-2.0 version workstation.Results: 7-O-amino acids chrysin derivatives 6 a–6 l were synthesized and their inhibitory effects were evaluated by comparing the material chrysin with positive control drug 5-fluorouracil(5-FU). Among these derivatives, compound 5 b(IC50= 24.50 ± 2.26 μmol/L), 5 k(IC50= 24.30 ± 2.19 μmol/L), and 6 f(IC50= 24.61 ± 2.01 μmol/L) showed better inhibitory activities against MGC-803 cell lines, and compound 5 g(IC50= 13.15 ± 1.73 μmol/L) and 5 j(IC50= 12.34 ± 1.25 μmol/L) showed better inhibitory activities against MCF-7 cell lines than chrysin and 5-FU. Molecular docking scores showed a credible consistency compared with MTT results.Conclusion: Compounds 5 b, 5 d, 5 g, 5 j, 5 k, and 6 f showed good antiproliferative effects on specific tumor cells, and compound 5 g should be researched further when according to molecular docking.

Potential therapeutic activities and novel delivery systems of chrysin-a nature’s boon

Flavonoids are a diverse group of phytonutrients that have gained attention as dietary supplements due to their broad spectrum of therapeutic properties and negligible side effects.Chrysin,a 5,7-dihydroxyflavone,has been explored for various pharmacological effects in the last few decades.Despite vast biological activities,the use of this polyphenol seems to be compromised due to low solubility,extensive pre-systemic metabolism and thus very poor oral bioavailability.The present review elucidates various pharmacological actions of chrysin such as cardioprotective,antioxidant,neuroprotective,hepatoprotective,anti-inflammatory,anticancer and antidiabetic activities with the help of reported scientific studies.Additionally,it focuses on different formulations developed for chrysin to increase its absorption and subsequent bioavailability.This review thus analyses the beneficial effects of chrysin and gives an overview of possible techniques adopted to increase its systemic bioavailability.