MODIFICATING ACTION OF DICLOFENAC ON EFFECTS OF PHOTODYNAMIC THERAPY – IN VIVO STUDY

Abstract

Introduction. Non-steroidal anti-inflammatory drugs and, in particular, diclofenac, are considered as drugs with a potentially anticarcinogenic effect and can be used to enhance the effects of antitumor therapy. Aim. To evaluate the effectiveness of diclofenac as a potential modifier of photodynamic therapy (PDT) in vivo in Ehrlich tumor model in mice. Materials and methods. The study was conducted on male mice of BALB/C strain with intradermally grafted Ehrlich carcinoma. Experimental procedures were performed on day 7 after tumor inoculation. The control group did not receive treatment, in one group only diclofenac was administered, photosensitizer was administered in three groups (photoditazin, 5 mg / kg, intravenously once), tumor was irradiated with a laser (ALOD, 662 nm) or PDT was performed, respectively, and in three groups the procedures indicated above in each case were combined with the administration of diclofenac. 2 series of experiments were conducted to assess the reproducibility of the results. The size of the tumor was recorded after exposure. Results. In the first series of the experiment, in all groups with the administration of diclofenac (45 mg/kg/day), a high animal mortality was unexpectedly observed, associated with the toxic effect of diclofenac, which required a change in its administration regime and dose (15 mg/kg) in the second series of the experiment. The administration of diclofenac did not significantly affect the efficacy of PDT, and also did not have a modifying effect in other groups (with the introduction of a photosensitizer or laser irradiation) compared with similar groups without diclofenac. PDT with photoditazine turned out to be the most effective treatment regimen: in 8 out of 10 mice in the group from the 21th day after procedure the tumors were not recorded, the animals were alive until the end of the observation for 60 days. The introduction of a photosensitizer and radiation without a photosensitizer did not lead to a significant inhibition of tumor growth. Conclusion. In vivo on a model of intradermally grafted Ehrlich tumor in mice, diclofenac does not have a modifying effect on the antitumor effects of PDT.