Alpha-Tocopheryl Succinate-Conjugated G5 PAMAM Dendrimer Enables Effective Inhibition of Ulcerative Colitis

Ulcerative colitis (UC) is a severe inflammatory disease in colon, however, the therapeutic efficacy of the standard-of-care in clinic for UC patients is unsatisfactory. To explore new drugs for effective and safe treatment of UC, alpha-tocopheryl succinate (α-TOS) is conjugated to generation 5 (G5) poly(amidoamine) (PAMAM) dendrimer to construct a nanodevice of G5-NH-acetamide (Ac)-TOS. The inhibitory effects of the G5-NH-Ac-TOS on UC are evaluated in vivo in a dextran sulfate sodium induced UC mouse model, and its mechanisms are explored in vitro in lipopolysaccharide stimulated mouse peritoneal macrophages. The results indicate that the G5-NH-Ac-TOS exhibits greater inhibitive effects on UC than free α-TOS, through significant attenuation of the disease activity index and reduction of macrophage infiltration in the colon tissues. The protective mechanisms of the G5-NH-Ac-TOS are revealed to be related to inhibition of expression of nuclear translocation of NF-κB, phosphorylation of Akt, and reduction of reactive oxygen species production in the macrophages.