Cinobufagin exerts anti-proliferative and pro-apoptotic effects through the modulation ROS-mediated MAPKs signaling pathway

Abstract

Cinobufagin (CBG) is a cardiotoxic bufanolide steroid secreted by the skin and parotid venom glands of the Asiatic toad Bufo bufo gargarizans (called Chan-Su). Although CBG is known to exhibit anti-cancer activities, very little is known about its potential mechanism(s) of action. In this study, we investigated whether CBG mediates its effect through the modulation of the mitogen-activated protein kinases (MAPKs) signaling pathway in human multiple myeloma (MM) U266 cells. We found that CBG caused the significant activation of ERK, JNK and p38 MAPK in U266 cells. CBG showed much higher cytotoxicity against U266 cells as compared to peripheral blood mononuclear cells (PBMC). Induction of CBG increased reactive oxygen species (ROS) generation from mitochondria, which is associated with the induction of apoptosis as characterized by increased sub-G1 DNA contents of cell cycle, positive Annexin V binding, activation of caspase-3 and cleavage of PARP. Inhibition of ROS generation by N-acetyl-l-cysteine (NAC) significantly prevented CBG-induced ERK, JNK and p38 MAPK activation and apoptosis. CBG also down-regulated the expression of various downstream gene products that mediate cell proliferation, survival, angiogenesis and metastasis. Interestingly, ERK, JNK and p38MAPK pharmacological inhibitors blocked CBG-induced MAPKs activation and ERK inhibitor (PD98059) also prevented the CBG-induced caspase-3 activation and PARP cleavage in U266 cells. Taken together, these findings suggest that CBG can act as a potent anticancer agent against MM and possibly exerts its effects through the ROS-mediated activation of ERK, JNK and p38 MAPK leading to the activation of caspase-3 in U266 cells.     

HPLC法测定蒡芩慢咽滴丸中酯蟾毒配基及华蟾酥毒基的含量

目的:建立用HPLC测定蒡芩慢咽滴丸中蟾酥内酯含量的方法。方法:采用十八烷基键合硅胶色谱柱(250mm×4.6mm,5μm),以乙腈-0.5%磷酸二氢钾溶液(用磷酸调pH值为3.2)(32∶68)为流动相,检测波长为296nm,柱温40℃。结果:酯蟾毒配基及华蟾酥毒基的线性范围分别为0.2～1.0μg(r=0.9997)及0.224～1.12μg(r=0.9996),平均回收率(n=6)分别为99.91%(RSD=0.7960%)和99.84%(RSD=1.0023%)。结论:该方法简单可靠。     

高效液相色谱法测定消炎解毒软膏中华蟾酥毒基和脂蟾毒配基的含量

目的建立消炎解毒软膏中华蟾酥毒基和脂蟾毒配基含量测定方法。方法采用HPLC法测定消炎解毒软膏中华蟾酥毒基和脂蟾毒配基的含量,色谱条件为Alltima C18：色谱柱（4.6mm×250mm,5μm）;流动相：水-乙腈（50∶50）,流速：1mL·min-1;检测波长：296nm;柱温：35℃。结果华蟾酥毒基的进样量在0.427～17.080μg峰面积积分值与进样量有良好的线性关系（r=0.9999）,平均回收率为98.3%,RSD为2.0%（n=6）;脂蟾毒配基的进样量在0.262～10.480μg峰面积积分值与进样量有良好的线性关系（r=0.9999）;平均回收率为98.9%,RSD为1.8%（n=6）。结论本方法简便、快速准确、灵敏度高、重现性好,可作为该制剂的含量测定方法。     

蟾酥通痹软膏的质量标准研究

目的:建立蟾酥通痹软膏(蟾酥、冰片、防己等)的质量标准。方法:采用TLC法对处方中的防己等进行定性鉴别;用HPLC法测定了华蟾酥毒基和脂蟾毒配基的含量。结果:在TLC图谱中可检出防己等药材的特征斑点;华蟾酥毒基在1.15μg~5.75μg之间线性关系良好,r=0.999 7,精密度实验RSD为1.05%,平均回收率为97.95%,(RSD=1.63%,n=5);脂蟾毒配基在1.05μg~5.25μg之间线性关系良好,r=0.999 6,精密度实验RSD为1.02%,平均回收率为97.45%,(RSD=0.61%,n=5)。结论:所采用方法准确、可靠,可行性及重复性良好,能有效控制该制剂的质量。     

华蟾素对原位膀胱癌大鼠的影响

目的：建立荷人膀胱癌的原位动物模型,通过磁共振成像（MRI）监测肿瘤生长过程,并利用此模型评价华蟾素抗膀胱癌作用．方法：直视下经尿道机械BALB／c裸鼠膀胱黏膜,将人膀胱癌细胞T24经尿道种植于25只裸鼠膀胱,建立荷人膀胱癌原位动物模型．以钆-二乙三胺五乙酸作为膀胱造影剂,用MRI监测肿瘤的生长,同时取裸鼠膀胱组织标本行HE染色进行病理学检查．同法建立膀胱癌动物模型18只,分为对照组和给药组,各9只．膀胱灌注6次后,荷瘤膀胱称质量．结果：25只裸鼠在种植T24细胞后均形成膀胱肿瘤,种植后7d,裸鼠膀胱MRI检查无明显变化,14,21,28d MRI检查均可发现膀胱不同程度的充盈缺损,MRI图像与肿瘤实际大小吻合．病理检查显示,种植后7d,肿瘤生长于裸鼠膀胱黏膜或浅层肌肉,14～28d局限于肌层,35d时侵及浆膜层．华蟾素给药组抑瘤率为46．9％．结论：成功建立了裸鼠原位膀胱癌动物模型,肿瘤生长基本模拟了人膀胱癌的发生、发展过程,MRI检查可作为对裸鼠膀胱原位肿瘤动态观察的可靠方法,华蟾素确有明显的抗膀胱癌的作用．     

HPLC法测定蟾皮中蟾毒配基类成分的含量

目的用HPLC法测定蟾皮中蟾蜍灵、脂蟾毒配基、华蟾蜍精等成分的含量。方法样品经乙醇室温浸渍提取,采用HPLC法测定。色谱柱为DiamonsilTMC18(250 mm×4.6 mm,5μm),流动相为甲醇-乙腈-水(体积比为4∶1∶5),流速为1.0 mL.min-1,检测波长为296 nm,柱温为40℃。结果蟾蜍灵、脂蟾毒配基和华蟾蜍精分别在0.0848~0.5088、0.0884~0.5304和0.2000~1.2000μg内与色谱峰面积线性关系良好,相关系数r分别为0.9999、0.9992和1.0000。蟾蜍灵、脂蟾毒配基和华蟾蜍精的平均回收率分别为99.3%、99.6%和99.0%,RSD分别为0.5%、0.2%和0.6%(n=9)。结论HPLC法可用于蟾皮中蟾蜍灵、脂蟾毒配基和华蟾蜍精的含量测定。     

Immunomodulatory effects of cinobufagin isolated from Chan Su on activation and cytokines secretion of immunocyte in vitro

The objective of this study was to evaluate the immunomodulatory effects of cinobufagin (CBG) isolated from Chan Su (Venenum Bufonis) in vitro. In this paper, our results show that CBG signi?cantly stimulated cell proliferation of splenocytes and peritoneal macrophages (PMΦ) and markedly enhanced the phagocytic activation of PMΦ. CBG also significantly increased CD4⁺CD8⁺ double-positive T-cell populations and the percentage of S-phase cells of splenic lymphocytes. The levels of several Th1 cytokines, including interferon-γ and tumor necrosis factor-α, are signi?cantly increased after CBG treatment, whereas the levels of the Th2 cytokine interleukin-4 and interleukin-10 are signi?cantly decreased. As a result, the ratio of Th1/Th2 also increased. Taken together, these results indicated that CBG had potential immune system regulatory effects and suggested that this compound could be developed as a novel immunotherapeutic agent to treat immune-mediated diseases such as cancer.     

反相高效液相色谱法测定梅花点舌丸中酯蟾毒配基、华蟾毒配基的含量

目的 :建立测定梅花点舌丸中酯蟾毒配基、华蟾毒配基的反相高效液相色谱法。方法 :采用KromasilC18 柱 ,流动相为乙腈∶0 5 %KH2PO4 溶液 (50∶50) ,检测波长为296nm。结果 :该方法线形关系良好 ,酯蟾毒配基的平均加样回收率为97 40 % ,RSD为2 2 % ;华蟾毒配基的平均加样回收率为97 78 % ,RSD为2 6 %。结论 :方法简便可靠 ,分离度较好 ,可用于梅花点舌丸的质量控制。     

灵猫香解毒丸的质量标准研究

目的:制定灵猫香解毒丸的含量测定标准.方法:采用反相高效液相色谱法测定蟾酥中华蟾酥毒基和酯蟾毒配基.结果:华蟾酥毒基和酯蟾毒配基分别在48.84～784.44,50.28～804.48 ng与峰面积呈良好线性关系,平均回收率100.5%,100.3%.结论:本实验定量方法简便、实用,重复性好,能够较好控制灵猫香解毒丸的质量.     

RP-HPLC测定蕲龙胶囊中华蟾酥毒基和酯蟾毒配基的含量

目的建立蕲龙胶囊中华蟾酥毒基和酯蟾毒配基的含量测定方法。方法采用高效液相色谱法,Phenomenex lunaC18(250 mm×4.6 mm,5μm)色谱柱,流动相为乙腈-水(50:50),流速0.8 mL/min,检测波长296 nm。结果方法学考察结果表明,本研究建立的分析方法有较好的重现性和稳定性。华蟾酥毒基平均加样回收率为98.5%(RSD=0.55%,n=6);酯蟾毒配基平均加样回收率为101.0%(RSD=0.67%,n=6)。结论本方法定量准确、重复性好,可用该制剂的质量控制。