The field of microbial pigments is an emerging area in natural products science. Carotenoids form a major class of such pigments and are found to be diversely synthesized by microorganisms that reside in hypersaline ecosystems to provide resistance against oxidative stress. Human cells can benefit from compounds such as carotenoids as antioxidant agents through either their capability to quench free radicals or their effect on promoting the antioxidant defense pathway. In this study, the antioxidant effectiveness of carotenoid extract from an extremely halophilic archaeon Halovenus aranensis strain EB27^T has been evaluated using different approaches. Finally, the ability of the extracted pigment to induce the antioxidant defense pathway of human primary skin fibroblast cells was studied. Hvn. aranensis carotenoid extract exhibited strong effectiveness such that at 2 µg/ml, the carotenoid extract fully neutralized the oxidative stress of hydrogen peroxide at its EC50 based on MTT assay. Results from real-time PCR of relevant genes, luciferase bioreporter of oxidative stress, and the western blot analysis further confirmed the antioxidant capability of the carotenoids. It was also shown the carotenoid extract had more antioxidant activity compared to β-carotene the same concentration. Results suggest the carotenoid extract from this archaeon to have high potential for clinical and industrial applications.

微生物色素领域是天然产物科学的新兴领域。类胡萝卜素形成了此类色素的主要类别，并且被发现由存在于高盐度生态系统中的微生物以多种方式合成，以提供对氧化应激的抵抗力。人类细胞可以通过类胡萝卜素等化合物作为抗氧化剂，通过它们淬灭自由基的能力或它们对促进抗氧化防御途径的作用而受益。在这项研究中，来自极端嗜盐古菌Halovenus aranensis EB27 ^T菌株的类胡萝卜素提取物的抗氧化作用已经使用不同的方法进行了评估。最后，研究了提取的色素诱导人原代皮肤成纤维细胞抗氧化防御途径的能力。恩。aranensis类胡萝卜素提取物表现出很强的有效性，根据 MTT 测定，在 2 µg/ml 时，类胡萝卜素提取物在其 EC50 下完全中和过氧化氢的氧化应激。相关基因的实时 PCR、氧化应激的荧光素酶生物报告基因和蛋白质印迹分析的结果进一步证实了类胡萝卜素的抗氧化能力。还表明，与相同浓度的 β-胡萝卜素相比，类胡萝卜素提取物具有更高的抗氧化活性。结果表明，来自这种古细菌的类胡萝卜素提取物具有很高的临床和工业应用潜力。