Zebrafish (Danio rerio), is a well‐established vertebrate animal model widely used in developmental biology and toxicological research. In the present study, foldscope is used as an innovative tool to study the developmental stages and toxicological analysis of the zebrafish embryos. Briefly, the developmental stages, such as zygote, cleavage, blastula, gastrula, segmentation, and pharyngula formation are observed and documented using simple foldscope. Toxicological parameters upon exposure to different concentration of ethanol extract of Curcuma longa and its lead compound, ar‐turmerone along with rhodamine B (bio‐coupler) on zebrafish embryos are analyzed upto 72 hr using foldscopes in live condition. The lethal endpoints, such as coagulation, lack of somite formation, non‐detachment of tail, and lack of heartbeat are clearly monitored and documented using foldscope. Bio‐evaluation of test compounds with the aid of foldscope confirms that the toxicity is directly proportional to the concentration. Our results conclude that, ethanol extract of C. longa, ar‐turmerone and rhodamine B exposed embryos remains healthy up to 96, 48, and 24 µg concentrations, respectively. Embryos exposed to higher concentrations become coagulated, however normal physiological active movement of tail lashing and heartbeat are evident in lower concentration exposed embryos. Except coagulation, no other abnormalities are observed and interestingly, the hatching ability is not delayed, when compared with the control embryos. It is confirmed that the test compounds are not highly toxic to zebrafish embryos. Hence it can be used for further analysis, especially for studying the neural‐regeneration and its neuronal development in zebrafish embryos.

中文翻译：

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斑马鱼 (Danio rerio) 胚胎的发育阶段和使用折叠显微镜的毒理学研究。

斑马鱼（Danio rerio）是一种成熟的脊椎动物模型，广泛用于发育生物学和毒理学研究。在本研究中，foldscope 被用作研究斑马鱼胚胎发育阶段和毒理学分析的创新工具。简而言之，使用简单的折叠镜观察和记录发育阶段，例如受精卵、卵裂、囊胚、原肠胚、分割和咽部形成。暴露于不同浓度姜黄乙醇提取物的毒理学参数及其先导化合物阿姜黄酮和罗丹明 B（生物偶联剂）在斑马鱼胚胎上使用折叠镜在活体条件下进行长达 72 小时的分析。使用 foldscope 清楚地监测和记录致命终点，例如凝血、体节形成不足、尾部不脱离和心跳不足。借助折叠镜对测试化合物的生物评估证实，毒性与浓度成正比。我们的结果得出结论，C. longa 的乙醇提取物，阿姜黄酮和罗丹明 B 暴露的胚胎分别在 96、48 和 24 µg 浓度下保持健康。暴露于较高浓度的胚胎会凝固，但在暴露于较低浓度的胚胎中，尾部鞭打和心跳的正常生理活动运动是明显的。除了凝固，没有观察到其他异常，有趣的是，与对照胚胎相比，孵化能力没有延迟。经证实，测试化合物对斑马鱼胚胎没有高毒性。因此，它可用于进一步分析，特别是研究斑马鱼胚胎的神经再生及其神经元发育。