This paper deals with two potential modes for the treatment of skin cancer-one a novel approach using a squaraine dye
and the other using a natural product- the flavonoid fraction of Saraca asoka. Squaraine dye is a photosensitizing agent,
which is preferentially taken up and retained by the tumor cells and when irradiated with high power visible light results
in the selective destruction of the tumor cells by photodynamic therapy. The uniqueness of this mode of treatment lies in
the selective destruction of tumor cells without affecting the neighbouring normal cells, which is much advantageous
over radiation therapy now frequently used. The chemopreventive and therapeutic effects of the plant component are
explored as well. The experimental models were Swiss albino mice in which skin tumor was induced by DMBA. Marked
reduction in tumor volume and burden in the treated groups were observed. The reversal of biochemical enzyme markers
like rhodanese, myeloperoxidase, β-D glucuronidase, lactate dehydrogenase, hexokinase and sialic acid to near normal
levels were observed in the PDT and flavonoid fraction treated groups. The live photographs of the experimental animals
and histopathological data further support the obtained results. The study assumes importance as it combines a
traditional treatment mode and a novel aspect in cancer therapy using the same experimental models. Also this is the first
report on PDT using a squaraine dye for skin cancer therapy in vivo.
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