Niemann-Pick type C disease (NPC) is a fatal, autosomal recessive disorder, which causes excessive accumulation of free cholesterol in endolysosomes, resulting in progressive hepatomegaly and neurodegeneration. Currently, 2-hydroxypropyl-β-cyclodextrin (HP-β-CyD) is used at a high dose for the treatment of NPC, risking lung toxicity and hearing loss during treatment. One method to reduce the required dose of HP-β-CyD for the treatment of hepatomegaly is to actively deliver β-cyclodextrin (β-CyD) to hepatocytes. Previously, we synthesized lactosyl-β-CyD (Lac-β-CyD) and demonstrated that it lowers cholesterol in NPC model liver cells. In the present study, we studied the efficacy and safety of Lac-β-CyD treatment of hepatomegaly in Npc1−/− mice. After subcutaneous administration, Lac-β-CyD accumulated in the liver and reduced hepatomegaly with greater efficacy than HP-β-CyD. In addition, subcutaneous administration of a very high dose of Lac-β-CyD was less toxic to the lungs than HP-β-CyD. Notably, the accumulation of intracellular free cholesterol in endolysosomes of NPC-like liver cells was significantly lower after administration of Lac-β-CyD than after treatment with HP-β-CyD. In conclusion, these results suggest that Lac-β-CyD is a candidate for the effective treatment of hepatomegaly in NPC.
