The present study was carried out to assess the photosensitizing potential of
embelin, the biologically active natural product isolated from Embelia ribes in
photodynamic therapy (
PDT) experiments in vivo. In vitro
PDT clearly indicated that
embelin recorded significant cytotoxicity in Ehrlich's
Ascites Carcinoma (EAC) cells, which is superior to 5-aminolevulinic
acid, a known photodynamic compound. For in vivo experiments solid
tumor was induced using EAC cells in the male Swiss albino mice of groups I, II, III and IV. Group I served as the control (without solid
tumor), group II served as
tumor bearing mice without treatment and groups III and IV served as treatments. At the completion of 4 weeks of induction, the
tumor bearing mice from group III and IV were given an
intraperitoneal injection with
embelin (12.5mg/kg
body weight). After 24h,
tumor area in the Group III and IV animals was exposed to visible light from a 1,000 W
halogen lamp. The mice from groups I to III were sacrificed 2 weeks after the
PDT treatment and the marker
enzymes (
myeloperoxidase [MPO], β-d-
glucuronidase, and
rhodanese) were assayed and expression of Bcl-2 and Bax were analyzed in normal and
tumor tissues. Animals from group IV were sacrificed after 90 days of
PDT treatment and the above mentioned parameters were recorded. Reduction in
tumor volume and reversal of
biochemical markers to near normal levels were observed in the treated groups. This is the first report on
PDT using a natural compound for solid
tumor control in vivo. The uniqueness of the mode of treatment lies in the selective uptake of the nontoxic natural compound,
embelin from the medicinal plant E. ribes used in Indian system of medicine, by the solid
tumor cells and their selective destruction using
PDT without affecting the neighboring normal cells, which is much advantageous over
radiation therapy now frequently used.