Toxic effects and changes of blood components by photodynamic action induced by pheophorbide-a in rats [Chlorella-derived substances, Japan]

In order to clarify the effects of pheophorbide-a, a Chlorella-derived substance with photodynamic activity, the substance was administered orally to rats and on the following day they were irradiated with 20, 000 lux of visible light. The toxic effects on these animals were observed, and analysis of blood components and of the resistance of erythrocytes was performed. The results obtained were as follows: 1) Redness was frequently observed on the skin at the auricle and the tail, but scarcely any edema was observed at the occipital and the dorsal positions. 2) LD50 of pheophorbide-a was reduced as the irradiation time with visible light was increased. 3) Toxicity of pheophorbide-a to rats no longer seen by the 4th day after administration, so this substance might be relatively quickly excreted or decomposed. 4) The number of erythrocytes, levels of hemoglobin concentration and hematocrit were increased in the experimental animals. It was also observed that the percentage of rod-shaped nuclear neutrophilic leukocytes in the leukocyte population increased (p