Betalains are plants pigments identified as potent antioxidant molecules, naturally present in foods like beetroot and prickly pears. Although activities described for betalain-containing formulations include cancer prevention and treatment, the use of extracts instead of purified pigments has avoided the investigation of the real chemopreventive and chemotherapeutic potential of these phytochemicals. Three betalain-rich extracts and six individual pure betalains were used in this work to characterize the activity and to explore possible molecular mechanisms. The animal model Caenorhabditis elegans (tumoral strain JK1466) was used to evaluate the effect of betalains as chemotherapeutics drugs. An objective evaluation method of tumor growth in C. elegans has been developed to assess the possible antitumoral activity of the different treatments. This protocol allowed a fast and reliable screening of possible antitumoral drugs. Among the betalains tested, tryptophan-betaxanthin reduced tumor size by 56.4% and prolonged the animal’s lifespan by 9.3%, indicating high effectiveness and low toxicity. Structure–activity relationships are considered. Assays with mutant strains of C. elegans showed that the mechanism underlying these effects was the modulation of the DAF-16 transcription factor and the insulin signaling pathway. Our results indicate that tryptophan-betaxanthin and related betalains are strong candidates as antitumoral molecules in cancer treatment.

中文翻译：

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秀丽隐杆线虫肿瘤模型中色氨酸-虾青素和相关植物甜菜碱的抗肿瘤药物潜力。

甜菜素是被认为是有效的抗氧化剂分子的植物色素，天然存在于甜菜根和刺梨等食物中。尽管所描述的含甜菜碱制剂的活性包括预防和治疗癌症，但使用提取物代替纯化的色素已避免了对这些植物化学物质真正的化学预防和化学治疗潜力的研究。在这项工作中使用了三种富含betalain的提取物和六个单独的纯betalains来表征活性并探索可能的分子机制。使用动物模型秀丽隐杆线虫（肿瘤菌株JK1466）评估甜菜碱作为化学治疗药物的效果。线虫肿瘤生长的客观评价方法已经开发出用于评估不同疗法可能的抗肿瘤活性的药物。该方案允许对可能的抗肿瘤药物进行快速可靠的筛选。在所测试的甜菜碱中，色氨酸-甜菜黄素使肿瘤大小降低了56.4％，并使动物的寿命延长了9.3％，表明其有效性和低毒性。考虑结构－活动关系。秀丽隐杆线虫突变株的测定表明，这些作用的基础是DAF-16转录因子和胰岛素信号通路的调节。我们的结果表明，色氨酸-β-黄嘌呤和相关的β-小分子在癌症治疗中作为抗肿瘤分子是很强的候选者。