去水淫羊藿素对大鼠视网膜缺血/再灌注损伤的保护作用

目的 研究去水淫羊藿素(ICT)对大鼠视网膜缺血/再灌注损伤是否具有保护作用,并初步探讨其作用机制.方法 将40只SD大鼠采取随机数表法分为5组(n=8),通过夹闭一侧颈总动脉的方法构建大鼠视网膜缺血/再灌注(I/R)模型.分别于夹闭前,一次性经腹腔注射不同剂量(1.0 mg/kg、2.0 mg/kg、4.0 mg/kg)ICT;假手术组及模型组给予等体积生理盐水腹腔注射;假手术组只分离不夹闭,模型组与药物组建立视网膜I/R模型.各组分别在夹闭前、缺血30 min时行视网膜电流图(ERG)、眼底照相检查以及再灌注1 h后行ERG、眼底荧光血管造影(FFA)检查.再灌注6 h后获取视网膜,通过免疫印迹法检测白介素10(IL-10)蛋白表达水平.结果 与模型组比较,ICT治疗组能显著改善ERG的a波、b波振幅降低,使后极部视网膜缺血动脉明显扩张,并且能升高视网膜I/R损伤后视网膜组织IL-10蛋白表达水平[(1.02±0.44)vs(0.47±0.21)],差异有统计学意义(P<0.05).结论 ICT对视网膜缺血/再灌注损伤具有保护作用,其保护机制可能与上调抗炎细胞因子IL-10蛋白表达水平,抑制炎症反应有关.     

淫羊藿苷衍生物的制备及其雌激素样作用研究

目的:研究淫羊藿苷(icariin,ICA)及其衍生物淫羊藿素(icaritin,ICT)和去甲淫羊藿素(desmethyli-caritin,DICT)的雌激素样作用及其相关的构效关系.方法:ICA经纤维素酶水解成ICT,进一步在BBr3和CH2Cl2的体系中反应生成DICT;用不同浓度的化合物与雌激素敏感性人乳腺癌细胞株MCF-7和T47D分别共培养6 d和9 d,MTT法检测其对细胞的促增殖率,以此评价化合物雌激素样作用的强弱.结果:ICT、DICT促细胞增殖作用显著,10-6 mol/L浓度时促MCF-7细胞增殖作用分别是雌二醇(10-9 mol/L)的90.0%和94.0%(P<0.01);促T47D细胞增殖作用分别是雌二醇的65.6%,50.0%(P<0.01).ICA未呈现促MCF-7细胞和T47D细胞增殖作用.ICT、DICT的促细胞增殖作用被10-7 mol/L雌激素受体完全拮抗剂ICI 182、780完全抑制.结论:ICT和DICT具有促MCF-7细胞和T47D细胞增殖的雌激素样作用,而ICA未体现该作用.     

淫羊藿提取物中淫羊藿苷及其代谢产物在骨质疏松模型大鼠肾脏中的分布研究

目的：骨质疏松模型大鼠灌胃给予淫羊藿提取物后,利用HPLC法对其肾脏中的淫羊藿苷及其代谢产物（淫羊藿次苷Ⅰ、淫羊藿素、淫羊藿次苷Ⅱ）进行测定,以考察淫羊藿苷及其代谢产物在肾脏中的分布情况.方法：按118mg/kg（相当于淫羊藿苷）灌胃给予骨质疏松模型大鼠淫羊藿提取物后,于40min、1.5h、8h、24h取组织,经生物样品预处理后,利用HPLC法测定肾脏中各成分的浓度.色谱柱：Agilent Eclipse XDB-C18（4.6mm＆#215;250mm,5μm）;柱温为40℃;流动相：A（0.4％ HAC水）-B（甲醇）;流速为1.0mL/min进行梯度洗脱;检测波长为270nm.结果：淫羊藿提取物给药40min后在肾脏中即有分布且能被检测,1.5h浓度较高,其后逐渐消除或代谢为其代谢产物;其代谢产物淫羊藿次苷Ⅰ、淫羊藿素、淫羊藿次苷Ⅱ在肾中均被检测;给药8h后,淫羊藿苷在肾脏中浓度较低,其代谢产物仍维持一定浓度;给药24h后各成分逐渐消除.结论：淫羊藿苷在大鼠肾脏中有一定程度的蓄积,并且与其代谢产物共存于肾脏组织中,并能维持一定的时间,与中医学认为淫羊藿归肾经补肝肾强腰膝的理论相符。     

淫羊藿苷及其拟代谢物的雌激素样作用研究

目的:用雌激素受体(Estrogen Receptor,ER)表达阳性细胞株人乳腺癌细胞MCF-7检测淫羊藿苷及其拟代谢物的雌激素样活性[1]及构效关系。方法:用MTT法,增殖细胞核抗原(Proliferating CellNuclear Antigen,PCNA)免疫组化法检测其对体外培养MCF-7细胞增殖及细胞周期的影响;Real-timeRT-PCR法检测ERα、ERβ和PS2 mRNA表达水平变化。结果:淫羊藿素促进MCF-7增殖,而淫羊藿苷、淫羊藿次苷I和脱水淫羊藿素促增殖效应不明显;淫羊藿素10-9mol.L-1组PCNA阳性表达强于其它三组;淫羊藿素极显著增加ERα和PS2 mRNA的表达水平。所有受试物均不促进ERβmRNA表达。淫羊藿素促进ERα蛋白表达强于其它三组。结论:淫羊藿素有明显的雌激素样作用,而淫羊藿苷及其它两种受试物雌激素样作用不明显。四种受试物均不促进ERβmRNA表达。     

Icaritin induces lytic cytotoxicity in extranodal NK/T-cell lymphoma

Background

Extranodal NK/T-cell lymphoma (ENKL) is an aggressive hematological malignancy associated with Epstein–Barr virus (EBV) infection. It is often resistant to conventional chemotherapy and has a poor prognosis. Icaritin, a compound derived from Chinese herbal medicine, Herba Epimedii, has been reported to exert antitumor effects on a variety of cancer cell lines. In the present study, we investigated the cytotoxic effects of Icaritin on the two EBV-positive ENKL cell lines SNK-10 and SNT-8, along with the underlying molecular mechanisms.

Methods

ENKL cell lines SNK-10 and SNT-8 were exposed to different concentrations of Icaritin for the indicated time. Treated cells were analyzed for cell proliferation, cell cycle, and cell apoptosis. Phosphorylation of Stat3 and Akt proteins in signaling pathways and the EBV-encoded LMP1 proteins were measured by Western blot. Expression of EBV genes was assessed by Real-Time PCR.

Results

Our results showed that Icaritin dose-dependently inhibits ENKL cell proliferation and induces apoptosis and cell cycle arrest at G₂/M phase. Additionally, Icaritin upregulates Bax, downregulates Bcl-2 and pBad, and activates caspase-3 and caspase-9. The anti-proliferative and pro-apoptotic effects of Icaritin are likely mediated by inhibition of Stat3 and Akt pathways through LMP1 downregulation. Importantly, Icaritin induces EBV lytic gene expression in ENKL cells, and the combination of Icaritin and the antiviral drug ganciclovir (GCV) is more effective in inducing ENKL cells apoptosis than Icaritin or GCV alone.

Conclusions

These findings indicate that EBV-targeted approaches may have significant therapeutic potential for ENKL treatment.     

Icaritin induces cell death in activated hepatic stellate cells through mitochondrial activated apoptosis and ameliorates the development of liver fibrosis in rats

Aim of the study

Icaritin is an active ingredient extracted from the plant Herba Epimedium Sagittatum (Sieb. et Zucc.) Maxim. The purpose of this study is to investigate the effects and mechanisms of icaritin-induced cell death in activated hepatic stellate cells (HSCs) and ameliorating the development of liver fibrosis in rats.

Materials and methods

: In vitro, icaritin-induced cell death rates in HSC-T6 (rat) and LX-2 (human) HSC lines as well as normal hepatocyte cell lines HL-7702 (L02) and WRL-68 were assayed by MTT method, and the apoptotic ratios were detected by both flow cytometry and the Annexin-V-FITC Apoptosis Detection Kit. A Whole Rat Genome Microarray Kit was used to identify expression of interest genes through fold-change screening. In vivo study, experimental liver fibrosis models were built by carbon tetrachloride (CCl₄) or common bile duct ligation (CBDL) in Wistar rats. Icaritin (1 mg/kg/day, three days a week) was administered by gastric gavage for four weeks (n = 6 per group). At the end of the study, serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) as well as the contents of hydroxyproline and collagen I in liver tissues were measured. Histopathological changes and the distribution of activated HSCs were observed in the liver tissues using hematoxyline-eosin (HE) staining and immunohistochemical staining for α-smooth muscle actin (α-SMA).

Results

Icaritin induced apoptosis in HSC-T6 and LX-2 in a concentration- and time-dependent manner with little toxicity to normal hepatocyte cell lines. The IC₅₀ of icaritin in HSC-T6 was 12.83 μM at 48 h. Apoptotic ratio of HSC-T6 treated with 24 μM icaritin was 20.19%, and the G2 phase of the cell cycle did not occur (P < 0.05). Gene analysis showed that icaritin up-regulated Bak-1, Bmf and Bax expression while significantly down-regulated Bcl-2 expression (vs. control group, P < 0.01). These results suggested that mitochondrial pathway played an important role in icaritin-induced apoptosis in activated HSCs. In vivo results showed that icaritin reduced the number of activated HSCs, and brought the elevated levels of AST, ALT, hydroxyproline and collagen I to normal or near normal values (vs. model group, P < 0.05).

Conclusions

Icaritin can induce cell death in activated HSCs through mitochondria-mediated apoptosis, ameliorate the progression of hepatic fibrosis in rats, and could be a promising drug for treating liver fibrosis.     

淫羊藿素通过雌激素受体和骨形态发生蛋白信号诱导MC3T3-E1 subclone 14细胞分化

目的: 观察淫羊藿素(ICT)对MC3T3-E1 subclone 14前体成骨细胞株增殖、分化的影响,以及雌激素受体(ER)和骨形态发生蛋白(BMP)信号在分化中的作用。方法: WST-8、BrdU法检测ICT对MC3T3-E1 subclone 14细胞活力和增殖的影响;ICI182780阻断ER受体信号后,检测ICT和noggin对MC3T3-E1 subclone 14细胞碱性磷酸酶(ALP)活性、I型胶原(Col I)和骨钙素(BGP)的影响;实时荧光PCR检测ICT对BMP-2、4、7 mRNA表达的影响;Western blotting检测ER受体信号阻断后,ICT对Smad1/5/8蛋白磷酸化的影响。结果: ICT(0.1 μmol/L、1 μmol/L)可以提高MC3T3-E1 subclone 14细胞ALP、Col I、BGP和矿化结节数量(P<0.01或P<0.05),表明ICT有促分化的作用,但对细胞活力和增殖指数无明显影响;阻断ER受体信号后,ICT促分化作用明显下降(P<0.01);ICT可以提高BMP-2、4 mRNA的表达(P<0.01),但对BMP-7 mRNA无作用(P>0.01);阻断ER信号后,ICT 促Smad1/5/8磷酸化明显减弱(P<0.01)。进一步阻断BMP/Smad信号可以抑制ICT促分化的作用(P<0.01)。结论: ICT可以通过ER受体激活BMP/Smad信号通路,进而促进MC3T3-E1 subclone 14细胞的分化。     

Icaritin enhances sorafenib-induced apoptosis through a mitochondria-dependent pathway

Sorafenib remains the standard systemic treatment for advanced human hepatocellular carcinoma (HCC). However, the low response rate, high recurrence, and high progression limit the therapeutic efficacy. Therefore, a combination therapy strategy was advanced to strengthen the antitumor effects of sorafenib. In the present study, we aimed to evaluate whether icaritin could enhance the inhibitory effects of sorafenib on HCC cells and clarify the underlying mechanism. The cell viability was evaluated via MTT assay, and the synergistic inhibitory effects of sorafenib and icaritin were verified by calculating the combination index (CI). Their combined effects on cell proliferation or apoptosis were investigated using colony formation assay and flow cytometry. Mitochondrial membrane potential (MMP) was detected by flow cytometric assay. The protein expressions associated with the apoptotic pathway were determined by Western blotting analysis. The data demonstrated that sorafenib and icaritin exerted synergistic inhibitory effects on cell viability (CI < 1). Icaritin enhanced the inhibitory effect of sorafenib on colony formation and sorafenib-induced apoptosis of HCC cells. We discovered a reduced level of antiapoptotic Bcl-2 and an elevated level of proapoptotic protein Bax when the cells were exposed to the combination. The effect of cleaved and activated PARP was also enhanced. Cleaved caspase-9 and cleaved caspase-3 were increased markedly in the combination group. Furthermore, the combination of icaritin and sorafenib significantly increased the loss of MMP compared with the single treatment group and induced the release of cytochrome c from the mitochondria to the cytosol. These findings indicated that icaritin could enhance sorafenib-induced cytotoxicity and trigger sorafenib-induced apoptosis through a mitochondria-dependent pathway.     

Proliferation-stimulating effects of icaritin and desmethylicaritin in MCF-7 cells

Icariin, icaritin and desmethylicaritin are constituents of Epimedium with a similar structure to genistein and daidzein. Using the modified MCF-7 cell proliferation assay (E-SCREEN assessment system), these compounds were tested for their estrogen-like activities. Icaritin and desmethylicaritin, but not icariin, strongly stimulated the proliferation of MCF-7/BUS cells. Cell cycle analysis revealed that the proliferation stimulatory effect was associated with a marked increase in the number of MCF-7/BUS cells in S phase and a significant increase in the G2/M population, with effects similar to those of estradiol. These actions were dose dependent (range from 1 nM to 10 microM) and could be significantly inhibited by the specific estrogen receptor antagonist ICI 182,780 [7 alpha-[9(4,4,5,5,5-pentafluoropentyl)sulfinyl]nonyl)-estra-1,3,5(10)-triene-3,17beta-diol)]. The estrogen receptor-regulated progesterone receptor and PS2 mRNA levels were increased by treatment with icaritin or desmethylicaritin within 24 h and the effects were also reversed by ICI 182,780. It was concluded that icaritin and desmethylicaritin are novel phytoestrogens and that the estrogenic effects of icaritin and desmethylicaritin are mediated by the estrogen receptor.     

Icaritin Attenuates Lipid Accumulation by Increasing Energy Expenditure and Autophagy Regulated by Phosphorylating AMPK

Background and AimsLipid accumulation is the major characteristic of non-alcoholic fatty liver disease, the prevalence of which continues to rise. We aimed to investigate the effects and mechanisms of icaritin on lipid accumulation.MethodsCells were treated with icaritin at 0.7, 2.2, 6.7, or 20 µM for 24 h. The effects on lipid accumulation in L02 and Huh-7 cells were detected by Bodipy and oil red O staining, respectively. Mitochondria biogenesis of L02 cells was detected by MitoTracker Orange staining. Glucose uptake and adenosine triphosphate content of 3T3-L1 adipocytes and C2C12 myotubes were detected. The expression levels of proteins in the adenosine 5′-monophosphate-activated protein kinase (AMPK) signaling pathway, biomarkers of autophagy, and mitochondria biogenesis were measured by western blotting. LC3 puncta were detected by immunofluorescence.ResultsIcaritin significantly attenuated lipid accumulation in L02 and Huh-7 cells and boosted the mitochondria biogenesis of L02 cells. Icaritin enhanced glucose uptake, decreased adenosine triphosphate content, and activated the AMPK signaling pathway in 3T3-L1 adipocytes and C2C12 myotubes. Icaritin boosted autophagy and also enhanced the initiation of autophagic flux in 3T3-L1 preadipocytes and C2C12 myoblasts. However, icaritin decreased autophagy and promoted mitochondria biogenesis in 3T3-L1 adipocytes and C2C12 myotubes.ConclusionsIcaritin attenuates lipid accumulation by increasing energy expenditure and regulating autophagy by activating the AMPK pathway.