The Protective Effect of Antioxidants in Areca Nut Extract-Induced Oral Carcinogenesis

Objective: Oral submucous fibrosis (OSF) is the premalignant disorder associated with fibrosis and epithelial atrophy. Areca Nut (AN) is the most significant risk factors for OSF. However, the molecular mechanism behind AN induced OSF remains unclear, and there exists no effective treatment for the malignant disorder. We aimed to investigate whether AN-extract causes epithelial-mesenchymal transition (EMT) in oral keratinocytes, and evaluated the therapeutic potential of antioxidants. Methods: The HPV16 E6/E7-transfected immortalized human oral keratinocytes (IHOK) were employed in the present study. For the preparation of AN-extract, dried AN was dissolved in distilled water overnight. The solution was centrifuged and the supernatant was collected for further use. For the determination of change in cytokine levels, ELISA was performed. To investigate EMT-related protein expression and phenotype, immunoblot and immunofluorescence were performed. Results: Among tumor-promoting cytokines (Gro-α, IL-6 and IL-8), IL-6 was remarkably increased by AN in IHOK. AN-extract induced EMT phenotypes, such as cell elongation, up-regulation of vimentin and snail. After treatment with neutralizing antibody of IL-6, AN-induced snail expression was reduced remarkably. Collectively, AN-extract induced IL-6 expression and mediated EMT. The use of antioxidants (EGCG, glutathione and NAC) significantly reduced IL-6 expression in AN-treated IHOK. Also, AN-decreased E-cadherin and increased vimentin were reversed by antioxidants, indicating that the effectiveness of antioxidants in inhibiting IL-6-induced EMT by AN. Conclusion: AN promotes EMT and antioxidants interrupt AN-induced-EMT in oral keratinocytes. Consequently, it is proposed that antioxidants could prevent AN-induced carcinogenesis and function as a prototype for developing therapeutic interventions of OSF.     

槟榔提取物刺激口腔黏膜角朊细胞培养上清对成纤维细胞增殖活性的影响

目的：探讨槟榔提取物刺激口腔黏膜角朊细胞在黏膜下纤维性变发病中的作用。方法：采用不同浓度槟榔提取液刺激体外培养的角朊细胞,取细胞培养上清,MTT法观察细胞培养上清对成纤维细胞增殖的影响。结果：一定浓度槟榔提取液刺激的角朊细胞培养上清能促进成纤维细胞增殖;细胞培养上清对成纤维细胞增殖的促进作用存在个体差异。结论：槟榔成分可能通过改变口腔黏膜角朊细胞的活性而导致口腔黏膜下纤维性变的发生。     

Effect of betel chewing, tobacco smoking and alcohol consumption on oral submucous fibrosis: a case–control study in Sri Lanka

BACKGROUND: Oral submucous fibrosis (OSMF) is a chronic, insidious, disabling potentially malignant condition of the oral mucosa seen predominantly in south and Southeast Asia. No reports are hitherto available on the aetiological factors of OSMF based on Sri Lankan patients. METHODS: A total of 74 patients with OSMF and 74 controls who consecutively attended the Oral Medicine clinic at the Dental Hospital (Teaching) Faculty of Dental Sciences, University of Peradeniya, Sri Lanka were included in the study. Binary logistic regression analyses were performed to model the influence of betel chewing, smoking and alcohol use and to determine the effects of different combinations of chewing habits on OSMF. RESULTS: Betel chewing was the only significantly associated factor in the aetiology of OSMF (OR = 171.83, 95% CI: 36.35-812.25). There were no interaction effects of chewing, smoking and alcohol consumption in the causation of OSMF. CONCLUSION: The present study has shown a strong association of betel quid chewing (including tobacco as an ingredient) with the causation of OSMF.     

番石榴叶水提取物对糖尿病小鼠小肠α-葡萄糖苷酶活性的影响

目的 研究番石榴叶水提取物对α-葡萄糖苷酶的抑制作用.方法 蒸馏水浸提、浓缩、干燥制备番石榴叶水提取物.昆明小鼠链脲佐菌素腹腔注射诱导糖尿病模型,以小鼠小肠粘膜生理盐水匀浆液作为α-葡萄糖苷酶,与双糖底物孵育,比色法测定葡萄糖产量代表α-葡萄糖苷酶的活性.比较正常小鼠和糖尿病小鼠小肠粘膜α-葡萄糖苷酶活性,以及番石榴叶水提取物对小肠粘膜α-葡萄糖苷酶活性的影响,Lineweaver-Burk作图判断水提物对α-葡萄糖苷酶抑制作用类型.结果 番石榴叶水提取物对小肠α-葡萄糖苷酶活性具有较强的抑制作用,并呈剂量效应关系;对蔗糖酶和麦芽糖酶的半数抑制浓度(IC50)分别为1.0 g/L和3.0 g/L,抑制作用类型为竞争性和非竞争性混合型.结论 番石榴叶水提取物具有抑制糖尿病小鼠小肠粘膜α-葡萄糖苷酶作用.     

槟榔提取物体外诱导人口腔黏膜成纤维细胞增殖模型的建立

目的为研究口腔黏膜下纤维化的修复机制,建立体外人口腔黏膜成纤维细胞增殖模型。方法体外培养口腔黏膜成纤维细胞,并用波形蛋白、角蛋白免疫细胞化学方法鉴定;分别用0、5、50、100、150、200μg/mL浓度的槟榔提取液对培养的成纤维细胞诱导,MTT法检测细胞增殖。结果波形蛋白表达阳性,而角蛋白表达阴性;50、100μg/mL槟榔提取物促进口腔黏膜成纤维细胞增殖。结论培养的细胞为纯化的成纤维细胞,槟榔提取物诱导口腔黏膜成纤维细胞增殖的最佳浓度为50～100μg/mL。该模型可为进一步的研究提供实验基础。     

Areca nut extracts suppress the differentiation and functionality of human monocyte-derived dendritic cells

Wang C‐C, Chen T‐Y, Wu H‐Y, Liu T‐Y, Jan T‐R. Areca nut extracts suppress the differentiation and functionality of human monocyte‐derived dendritic cells. J Periodont Res 2012; 47: 198–203. © 2011 John Wiley & Sons A/S Background and Objective: Areca quid chewing, a major risk factor contributing to the occurrence of oral cancer and precancer, has been reported to be associated with the severity and high prevalence of periodontal diseases in areca quid chewers. As dendritic cells are critically involved in the regulation of innate and adaptive immunity in oral mucosa, the objective of the present study was to investigate the effect of areca nut extracts (ANE) on the differentiation and reactivity of dendritic cells derived from monocytes. Material and Methods: Human peripheral blood monocytes were cultured in the presence of granulocyte–monocyte colony‐stimulating factor and interleukin‐4 for 7 d to generate dendritic cells. To examine the effect of ANE on the generation of dendritic cells, the monocytes were exposed to ANE throughout the 7 d culture period. In addition, the effect of ANE on the maturation of monocyte‐derived dendritic cells induced by lipopolysaccharide (LPS) was examined. Results: Monocytes cultured in granulocyte–monocyte colony‐stimulating factor and interleukin‐4 exhibited a typical phenotype of dendritic cells, as evidenced by the heightened expression of human leukocyte antigen (HLA)‐DR, CD11c and the co‐stimulatory molecules CD40, CD80 and CD86. Exposure of the monocytes to ANE did not influence the expression of HLA‐DR and CD11c, but markedly attenuated the proportion of CD40‐positive cells and the mean fluorescence intensity of CD86. The expression of co‐stimulatory molecules in LPS‐activated dendritic cells was not affected, whereas the mRNA expression of interleukin‐12 induced by LPS was markedly suppressed by ANE treatment in a concentration‐dependent manner. Conclusion: These results suggest that ANE exposure interfered with the differentiation of dendritic cells from monocytes. Moreover, the functionality of mature monocyte‐derived dendritic cells was attenuated in the presence of ANE.     

响应面分析用于槟榔储藏条件考察的研究

探寻A.flavus菌株在槟榔原药材中生长及产黄曲霉毒素（AFB1,AFB2,AFG1和AFG2）的规律,分析槟榔药材的最佳储藏条件。采用响应面分析法（Response Surface Analysis,RSA）结合Central composite设计,通过测定染菌后的槟榔中水分含量及总黄曲霉毒素的变化,考察温度（Temp,20～40 ℃）和湿度（Hum,80%～95%）两个环境因子对药材上A.flavus菌株产毒的影响,分析该菌株的最适产毒条件。结果发现,储藏后的槟榔水分含量发生了显著的增加;当湿度范围为90%～95%,温度高于25 ℃时,A.flavus菌株在槟榔中生长较快并产生大量黄曲霉毒素。研究表明,当储存条件为湿度小于90%,温度低于25 ℃,槟榔药材在储藏过程中不易霉变产毒,为槟榔储藏规范的制定及降低真菌毒素污染的概率提供了较好的依据。     

槟榔致癌物质与口腔癌

槟榔为一级致癌物,咀嚼槟榔引起口腔癌缘于槟榔中的槟榔碱（ARC）、槟榔鞣质、槟榔特异性亚硝胺（ASNA）和活性氧（ROS）等具有细胞毒性、遗传毒性、致突变性和致癌性。ARC可诱导口腔成纤维细胞、角质形成细胞和人脐静脉内皮细胞程序性死亡。槟榔鞣质有否遗传毒性和致突变性至今仍有争议,不同类型的短期筛选试验结果差异很大,但含鞣质的槟榔多酚是槟榔的主要致癌成分。3-甲基亚硝氨基内醛可诱发人颊黏膜角质形成细胞的DNA链断裂和DNA蛋白交联。3-甲基亚硝氨基丙腈为强致癌剂,可诱发试验动物肿瘤,靶器官包括鼻腔、食管、舌等。槟榔咀嚼过程中可产生大量的ROS,造成DNA氧化性损伤和激活癌基因的方式促使癌症的发生。相对分子质量为3．0×10^4-10．0×10^4的槟榔提取物组分中一种新发现的蛋白聚糖通过增加胞内ROS水平及一系列信号级联放大,上调口腔癌细胞低氧诱导因子-1d的表达,最终诱导细胞自噬。细胞自噬有利于保护癌细胞免遭ARC诱导的程序性细胞死亡,促进口腔癌的发展。槟榔提取物还可能通过ROS增强舌鳞状上皮细胞癌细胞株刺激血小板聚集的效应,从而促进舌癌转移。     

蕃荔枝化合物L2-11对Heps荷瘤小鼠抗肿瘤作用的实验研究

目的:研究光叶番荔枝化合物L2-11对Heps荷瘤小鼠瘤体生长的抑制作用和对免疫的影响。方法:给予Heps荷瘤小鼠不同剂量的光叶番荔枝化合物L2-11连续8天,停药后处死小鼠,计算抑瘤率、脾指数、胸腺指数和NK细胞活性;观察ALT、AST、BUN、SCr和血常规。结果:光叶番荔枝化合物L2-11的20mg/kg、10mg/kg组能显著抑制Heps荷瘤小鼠的生长(P<0.05),平均抑瘤率分别为48.52%、35.55%,其中20mg/kg组疗效和5-FU相当;同时L2-11能显著提高Heps荷瘤小鼠的NK细胞活性,而对荷瘤小鼠肝、肾功能、血常规无明显影响。结论:光叶番荔枝化合物L2-11具有较显著的抗肿瘤作用,其机理部分可能与提高荷瘤小鼠的NK细胞活性、增强小鼠免疫功能有关。