Recent outbreaks of
variant Creutzfeldt-Jakob disease and iatrogenic
Creutzfeldt-Jakob disease have aroused great concern in many countries and have necessitated the development of suitable
therapies. We have demonstrated that sulfated
glycans such as
pentosan polysulfate and
fucoidan, and amyloidophilic compounds such as
amyloid dye derivatives, styrylbenzoazole derivatives, and
phenylhydrazine derivatives have efficacies in
prion-infected animals. Amyloidophilic compounds present potentialities not only as therapeutic candidates but also as
prion amyloid imaging probes for use in nuclear medicine technology such as positron emission tomography. A representative of styrylbenzoazole compounds has been used recently for clinical trials of brain
prion amyloid imaging in patients. On the other hand, a representative of
phenylhydrazine compounds,
compB, displays excellent effectiveness in prolonging the incubation times of infected animals when given orally. However, both its anti-
prion effectiveness in vitro and its therapeutic efficacy in vivo are consistently dependent on the
prion strain. This
prion-strain-dependency is similarly observed in other amyloidophilic compounds. Therefore, aside from further improvement of the safety profiles and pharmacokinetic properties of such compounds, elucidation and management in the mechanism of the
prion strain-dependent effectiveness is necessary. Nevertheless, because
compB studies suggest that amyloidophilic compounds are also therapeutic candidates for
Alzheimer's disease, amyloidophilic compounds might be attractive as
drug candidates for various conformational diseases and hasten development of therapeutic drugs for
prion diseases.