Treatment of Psoriasis by Topical Application of a small peptide (7 amino acids) which is a PEDF
This invention provides a novel small peptide (P5-2) which can be used for treating psoriasis. The
P5-2 consists of 7 amino acid residues which correspond to 388-394 amino acid residues of PEDF
(Pigment Epithelium-Derived Factor, 418 amino acid residues in total).
The P5-2 shows anti-psoriatic effects (reduction of epidermal thickness of the psoriatic skin) when
applied onto human psoriatic skin grafted onto rat.
Human psoriatic skin was grafted to rat and. 7 days after the graft, P5-2 or PBS (control) was injected
subcutaneously 3 times/week for 3 weeks. The thickness of psoriatic skin was significantly (p<0.05)
reduced when compared with control.
Left : Hematoxylin-eosin staining of the psoriatic skin after the treatment with P5-2.
Right : Bar graph showing the epidermal thickness after the treatment (ave. for 3 times)
Further, topical application of P5-2 onto the grafted skin reduced the epidermal thickness of the
psoriatic skin (Left panel) as well as the number of CD31 positive capillary endothelial cells in the
papillary dermis (Right panel).
It was further observed that topically applied P5-2 was detected in the dermis and colocalized with
endothelial Cells. This means that P5-2 penetrates into the psoriatic skin when topically applied onto
Biotin-labeled P5-2 was applied to the grafted skin and its localization
was analyzed 2 hours later using Rhodamine-Avidin staining.
Patent and status
PCT/JP2009/055165, patent pending at the international (PCT) stage
- Medicine for treating psoriasis.
- It is possible to develop an external drug containing the P5-2 for treating psoriasis.
- The P5-2 (7 amino acid residues) can be chemically or genetically produced.
Dr. Ri-ichiro Abe
Akio Hitoshio, IP manager