基于计算毒理学的遗传毒性评价研究进展

计算毒理学是一种使用计算方法分析、模拟、可视化或预测化学品毒性的毒性评估方法,在时间、成本和动物福利方面具有明显优势。近年来,使用计算工具预测遗传毒性正受到监管机构更多的关注,ICH M7指南表明在药品监管中认可应用(Q)SAR模型预测药物杂质的Ames致突变性。本文讨论了经典的遗传毒性计算评估方法及其原理,总结目前常用的遗传毒性评价模型及模型的构建现状,回顾计算毒理学在药物杂质、纳米材料和化妆品成分的遗传毒性评价中的应用,旨在为评价遗传毒性的计算模型的构建和优化提供一定参考,进一步促进计算毒理学在国家遗传毒性监管中的应用。     

天然药物成分致突变性风险预测与评价方法研究进展

天然药物成分复杂，无法逐一完成系统的致癌性风险评价及体内遗传毒性试验。鉴于计算机毒理学结合体外致突变风险评价方法在遗传毒性杂质致突变性评价方面的快速发展，也可考虑将此评价模式应用于天然药物成分的致突变性筛选与机制研究。从计算机毒理学和体外致突变性评价两方面出发，综述天然药物致突变性的研究方法，为其遗传毒性试验评价及监管提供借鉴。     

亚硝胺类遗传毒性杂质的监管策略及思考

如何对药品中存在致癌风险的亚硝胺类杂质进行控制,已成为企业和监管部门关注的热点。本文对亚硝胺类杂质的常见类型、来源、致癌性作用特点进行梳理,并结合EMA、FDA、ICH及我国相关遗传毒性杂质控制指导原则,对制定符合我国国情的亚硝胺类杂质的监管限度和监管工作提出建议。尽管国外已陆续出台了一系列针对药品中亚硝胺类杂质的含量限定的指南性文件,但众多亚硝胺类杂质的毒性剂量、人体暴露量尚不明确,且药物合成工艺存在差异,我国无法完全照搬欧美等国的监管方法。当前应深入研究亚硝胺类杂质的遗传毒性和致癌性,从而制定符合我国国情的监管限度值和药品中亚硝胺杂质监管策略;此外,本文从解决实际问题的角度出发,讨论如何根据已有指导原则,确定在已知毒理学数据、毒理学数据不足和短期使用药物不同情况下亚硝胺类杂质的监管限度。本文将为药物生产和杂质评价与研究和监管领域相关人员提供借鉴。     

亚硝胺类遗传毒性杂质的监管策略及思考

如何对药品中存在致癌风险的亚硝胺类杂质进行控制,已成为企业和监管部门关注的热点。本文对亚硝胺类杂质的常见类型、来源、致癌性作用特点进行梳理,并结合EMA、FDA、ICH及我国相关遗传毒性杂质控制指导原则,对制定符合我国国情的亚硝胺类杂质的监管限度和监管工作提出建议。尽管国外已陆续出台了一系列针对药品中亚硝胺类杂质的含量限定的指南性文件,但众多亚硝胺类杂质的毒性剂量、人体暴露量尚不明确,且药物合成工艺存在差异,我国无法完全照搬欧美等国的监管方法。当前应深入研究亚硝胺类杂质的遗传毒性和致癌性,从而制定符合我国国情的监管限度值和药品中亚硝胺杂质监管策略;此外,本文从解决实际问题的角度出发,讨论如何根据已有指导原则,确定在已知毒理学数据、毒理学数据不足和短期使用药物不同情况下亚硝胺类杂质的监管限度。本文将为药物生产和杂质评价与研究和监管领域相关人员提供借鉴。     

遗传毒性早期快速评价方法

遗传毒性评价是药物安全性评价的重要组成部分。如何早期、快速地获得药物可能的毒性反应数据,是当前遗传毒理学领域的研究热点之一。介绍几种目前应用比较广泛或有较好应用前景的早期、快速的遗传毒性评价方法,包括AmesII试验、Gadd45 Green Screen试验、高通量体外彗星试验和流式细胞术检测微核试验,主要围绕这些方法的基本原理、简要操作流程、预测毒性的可信度以及与传统方法相比的优缺点等展开。同时简要介绍计算机辅助毒性预测模型以及基因芯片技术在遗传毒性评价中的应用。     

药物杂质的毒理学评价要求及进展

 药物原料或制剂中的杂质可能引起临床不良反应。杂质毒理学评价是药物研究的重要内容。ICH关于药物及制剂杂质方面指导原则规定了杂质的报告、鉴定和质控限度,含量超过质控限度的杂质应进行毒理学评价。但指导原则对于研发阶段的药物杂质和遗传毒性杂质的限度未作明确要求。EMEA对于遗传毒性杂质制定了专门的指导原则,引入了毒理学担忧阈值（TTC）的概念对遗传毒性杂质限度进行控制,遗传毒性杂质每日接触量应小于1.5 μg。FDA也推荐采用TTC原则控制遗传毒性和致癌性杂质。本文结合ICH,EMEA及美国FDA等指导原则,对药物杂质毒理学评价的要求及其进展进行了综述。     

药品杂质遗传毒性评价的概述

本文综述了近年来国内外药品杂质遗传毒性评价的进展.药品遗传毒性评价的结果直接关系到药品杂质限度的制定,各种杂质的遗传毒性评价方法的研究进展迅猛,在现阶段条件下,使用计算机预测药品杂质的遗传毒性;探索以γH2AX为代表的生物标志物检测替代传统的体内外遗传毒性检测体系;并使用斑马鱼模式动物对其遗传毒性进行验证是行之有效的杂...     

符合中药特点的致癌风险评价方法

如何对中药的致癌性风险作出科学而合理的评价是毒理学研究的难点之一。因中药成分和配伍的复杂性,现有的常规遗传毒性评价方法在评价中药方面有所局限。在原有试验原理基础上开发高通量筛选方法,以及利用新型生物标志物和基于新原理的试验技术已在中药毒性预测和评价领域显露一定的应用价值。本文聚焦适合大量成分毒性筛选及靶器官毒性评价的试验方法,包括改良的传统试验方法、自动化检测手段、生物标志物、三维组织培养技术和计算机毒理学的引入等,为中药致癌性评价提供借鉴思路。     

我国遗传毒理学发展的回顾

回顾了中国遗传毒理学发展的三个阶段 :自 70年代末至 1983年为启动阶段 ,建立了一系列遗传毒性检测方法 ,筛检了大量环境化学物的遗传毒性 ,以及培训了大量专业人员 ,成立了中国环境诱变剂学会。自 1983～ 1993年为深入发展的关键阶段。遗传毒性检测方法标准化、规范化 ,开展遗传毒性机制的研究 ,遗传毒性试验列入新药、农药、食品、化妆品等安全性评价准则 ,并成立了中国毒理学会遗传毒理专业委员会。自 1993年至今 ,遗传毒理学进入了分子时代。建立了分子致突变测试系统 ,例如穿梭质粒载体系统 ,转基因动物致突变测试系统 ,以及其他应用分子生物学方法进行突变的分子分析等。开展了基因突变分子机制的研究 ,在非定标性突变方面取得了显著成就。并且 ,还回顾了遗传毒理在我国人类环境的现场监测、人群健康监测、遗传毒性与疾病、肿瘤的流行病学调查中的应用     

新药评价中遗传毒性试验方法学研究及其发展趋势

比较各国的新药遗传毒性评价方案 ,重点介绍 Ames试验和微核试验的研究进展、遗传毒性评价的新技术和新方法 (FISH技术、彗星试验等 ) ,并提出了新世纪遗传毒理学的发展趋势。     

齿痛消炎灵颗粒联合多西环素治疗慢性牙周炎的临床研究

目的探讨齿痛消炎灵联合多西环素治疗慢性牙周炎的临床疗效。方法选取2019年5月—2020年5月濮阳市第三人民医院收治的慢性牙周炎患者110例(139颗患牙),随机分为对照组(55例69颗牙)和治疗组(55例70颗牙)。对照组口服盐酸多西环素片,0.1 g/次,1次/d;治疗组在对照组基础上口服齿痛消炎灵颗粒,10 g/次,3次/d。两组均连续治疗4周。比较两组的临床疗效,观察两组牙周指标、外周血细胞因子水平、基质金属蛋白酶2(MMP-2)、基质金属蛋白酶组织抑制因子2(TIMP-2)的变化情况。结果治疗后,治疗组的总有效率是94.55%,显著高于对照组的78.18%(P0.05)。治疗后,两组口腔内牙周袋深度(PD)、菌斑指数(PLI)、出血指数(BI)、附着丧失(AL)和牙槽骨吸收(ABL)显著低于同组治疗前(P0.05);治疗组治疗后这些牙周指标明显低于对照组(P0.05)。治疗后,两组患者TNF-α、IL-6和HMGB水平明显低于同组治疗前,而IL-10显著提高(P0.05);治疗组治疗后这些外周血中细胞因子水平改善优于对照组(P0.05)。治疗后,两组MMP-2、TIMP-2、MMP-2/TIMP-2比值明显低于同组治疗前水平(P0.05);治疗后治疗组MMP-2、TIMP-2、MMP-2/TIMP-2比值明显低于对照组(P0.05)。结论齿痛消炎灵联合多西环素治疗慢性牙周炎疗效明显,可有效地降低炎症水平,从根本上改善牙周指标和基质金属蛋白酶,具有一定的临床推广应用价值。     

药物中肼类基因毒性杂质分析研究进展

基因毒性杂质具有在极低暴露水平下即能导致严重毒性的特点,对用药的安全性造成严重的威胁。作为一类重要的基因毒性杂质,肼是一种常见的中间体,而且是常见药物的降解产物。对基因毒性杂质进行了概述,并较为详尽地介绍了肼类基因毒性杂质的分析方法,为需要测定此类基因毒性杂质的分析人员提供参考。     

An evaluation of the sensitivity of the Ames assay to discern low-level mutagenic impurities

Low level impurities often reside in active pharmaceutical ingredients (API). Some of these impurities are potentially genotoxic since reactive intermediates are used in the synthetic route for the production of API. Routine mutagenicity testing is conducted in support of clinical trials with the intent to identify genotoxic hazards associated with API. Depending on the amount of impurity present in the API tested, the potency of the impurities and the relative sensitivity of the Ames assay, it is possible that mutagenicity associated with the presence of genotoxic impurities could also be detected while testing API. Therefore, we evaluated published data and generated new information to understand the sensitivity of the Ames assay. Based on a literature survey of approximately 450 mutagens, it was estimated that 85% of mutagens are detected at concentrations of 250 microg/plate or less. Based on this estimate, most mutagens should be detected in an Ames assay testing API concentrations up to 5000 microg/plate if present at a 5% or greater concentration. Data from experiments where several direct and indirect-acting mutagens were spiked into representative API further support the literature-based evaluation. Some limitations of this approach, including toxicity of API and competing metabolism are discussed.     

The application of structure-based assessment to support safety and chemistry diligence to manage genotoxic impurities in active pharmaceutical ingredients during drug development

Starting materials and intermediates used to synthesize pharmaceuticals are reactive in nature and may be present as impurities in the active pharmaceutical ingredient (API) used for preclinical safety studies and clinical trials. Furthermore, starting materials and intermediates may be known or suspected mutagens and/or carcinogens. Therefore, during drug development due diligence need be applied from two perspectives (1) to understand potential mutagenic and carcinogenic risks associated with compounds used for synthesis and (2) to understand the capability of synthetic processes to control genotoxic impurities in the API. Recently, a task force comprised of experts from pharmaceutical industry proposed guidance, with recommendations for classification, testing, qualification and assessing risk of genotoxic impurities. In our experience the proposed structure-based classification, has differentiated 75% of starting materials and intermediates as mutagenic and non-mutagenic with high concordance (92%) when compared with Ames results. Structure-based assessment has been used to identify genotoxic hazards, and prompted evaluation of fate of genotoxic impurities in API. These two assessments (safety and chemistry) culminate in identification of genotoxic impurities known or suspected to exceed acceptable levels in API, thereby triggering actions needed to assure appropriate control and measurement methods are in place. Hypothetical case studies are presented demonstrating this multi-disciplinary approach.     

In vitro toxicity assessment of rivaroxaban degradation products and kinetic evaluation to decay process

Degradation kinetics of oral anticoagulant rivaroxaban (RIV) was assessed in acid and alkaline media and while exposed to UVC radiation. Among all stress conditions tested, kinetic degradation process was better described by a zero-order model. A stability indicating method was validated for the analysis of the anticoagulant RIV in tablets by high-performance liquid chromatography. Robustness was evaluated with a two-level Plackett–Burman experimental design. The effect of acute exposition of the human hepatoblastoma HepG2 cell line to RIV stressed samples (100 and 500?µM) was assessed through in vitro toxicity tests. MTT reduction, neutral red uptake, mitochondrial membrane potential, and low molecular weight DNA diffusion assays were employed for cytotoxicity evaluation (5×10⁴ cells/well). The genotoxic potential was assessed by comet assay (2×10⁴ cells/well). Acute toxicity to HepG2 cells was assessed after 24?h incubation with sample solutions, for each test. A direct relationship between the increased amount of alkaline degradation products and higher cytotoxic potential was found. Results obtained by viability assay investigations support the concerns on risks associated with acute toxicity and genotoxicity of pharmaceutical samples containing degradation products as impurities.     

密蒙花的化学成分及质量控制方法研究进展

对密蒙花化学成分、质量评价体系及控制方法研究进展做系统分析,为进一步完善密蒙花的质量评价体系提供参考与依据。对大量国内外相关文献进行查阅、比较与分析,并对其进行归纳与综述。密蒙花中化学成分丰富,其中黄酮类、苯乙醇苷类、挥发油类和三萜类等为主要活性物质;其质量控制方法涉及传统的性状鉴别、显微鉴别、理化鉴别及光谱法、色谱法等多种技术。其质量控制方法虽多,但并不完善,面对掺伪造假、等级评价模糊等问题,建立一套灵敏度高及专属性强的密蒙花质量评价体系显得尤为重要。     

Evaluation of salidroside in vitro and in vivo genotoxicity

It is reported that salidroside, the main component of a traditional Chinese medicine, Rhodiola rosea, has the efficacy of protecting Coxsackie virus impairment. As part of a safety evaluation on salidroside for use in the treatment of viral myocarditis, the present study evaluated potential genotoxicity of salidroside by using the standard battery of tests (i.e., bacterial reverse mutation assay, chromosomal aberrations assay, and mouse micronucleus assay) recommended by the State Food and Drug Administration of China. The results showed that salidroside was not genotoxic under the conditions of the reverse mutation assay, chromosomal aberrations assay, and mouse micronucleus assay conditions. The anticipated clinical dose seems to be smaller than the doses administered in the genotoxicity assays. With confirmation from further toxicity studies, salidroside would hopefully prove to be a safe anti-Coxsackie virus agent.