A smart cauliflower-like carrier for astaxanthin delivery to relieve colon inflammation.

As a fat-soluble carotenoid, astaxanthin has excellent antioxidant and anti-inflammation biological activities, but its poor biocompatibility and low stability limit application of astaxanthin in the food industry. In this study, cauliflower-like carriers (CCs) were constructed based on caseinate, chitosan-triphenylphosphonium (TPP) and sodium alginate through an electrostatic self-assembly method to improve the biocompatibility, stability and targeting transport properties of astaxanthin. The smart CCs showed pH-response release and mitochondrial targeted characteristics. In vitro studies demonstrated that the CCs could improve the internalization of astaxanthin, and significantly inhibited the excessive production of reactive oxygen species and the depolarization of mitochondrial membrane potential caused by oxidative stress. In vivo studies revealed that the astaxanthin-loaded CCs could effectively relieve the colitis induced by dextran sodium sulfate and protect the integrity of the colon tissue structure. The astaxanthin-loaded CCs could significantly inhibit the expression of inflammation factors such as interleukin-1β, interleukin-6, tumor necrosis factor alpha, cyclooxygenase-2, myeloperoxidase, inducible nitric oxide synthase, and nitric oxide. Moreover, the astaxanthin-loaded CCs could maintain the expression of zonula occludens-1, increase the abundance of Firmicutes and Lactobacillaceae in the intestine. In a word, the constructed astaxanthin delivery system provided a potential application for the oral uptake hydrophobic bio-activator in intervention of ulcerative colitis.