Astaxanthin protects against renal fibrosis through inhibiting myofibroblast activation and promoting CD8 + T cell recruitment.

•Astaxanthin exhibited marked protective effects against renal fibrosis.•It inhibited fibroblast activation via Smad2, Akt, and STAT3.•It suppressed EMT in tubular epithelial cells via Smad2, snail, and β-catenin.•It promoted the accumulation of IFN-γ-expressing CD8+ T cells in the kidney.•To recruit CD8+ T cells, it upregulated the expression of CCL5 in macrophages.