Astaxanthin (AST) exists trans/cis forms in food. Currently, the functional activities and molecular mechanisms of the geometrical isomers remain unclear. In this study, the anti-aging activities of isomers were studied in Caenorhabditis elegans. The median lifespan of C. elegans fed with 9-cis, 13-cis and all-trans isomers was observed to increase by 59.39%, 24.99%, and 30.43%, respectively. AST isomers didn’t exert adverse effects on reproductive behavior, and could alleviate the decline in physiological function caused by senility in C. elegans. In addition, the decreased intracellular ROS accumulation was consistent with the life extension. RNA-seq analysis demonstrated that the lifespan extension was mediated primarily through the modulation of genes involved in the longevity regulating pathway, and was caused by the 9-cis (hsp-16.48, hsp-16.49) and all-trans (fat-5, pha-4) relative to the 13-cis. Furthermore, different isomers resulted in differences in anti-aging mechanisms through the regulation of the expression of specific differentially expressed genes.

虾青素（AST）以反/顺式形式存在于食物中。目前，几何异构体的功能活性和分子机理尚不清楚。在这项研究中，研究了秀丽隐杆线虫中异构体的抗衰老活性。饲喂9-顺式，13-顺式和全反式异构体的秀丽隐杆线虫的中位寿命分别增加了59.39％，24.99％和30.43％。AST异构体不会对生殖行为产生不利影响，并且可以缓解秀丽隐杆线虫衰老引起的生理功能下降。另外，减少的细胞内ROS积累与寿命延长是一致的。RNA-seq分析表明寿命延长主要是通过调节参与长寿调节途径的基因来介导的，并且是由9-顺式（hsp-16.48，hsp-16.49）和全反式（fat-5，pha-4）相对于13-顺式。此外，不同的异构体通过调节特定差异表达基因的表达而导致抗衰老机制的差异。