Possible in vivo mechanisms involved in photodynamic therapy using tetrapyrrolic macrocycles

Photodynamic therapy (PDT) mediated by oxidative stress causes direct tumor cell damage as well as microvascular injury. To improve this treatment new photosensitizers are being synthesized and tested. We evaluated the effects of PDT with 5,10,15,20-tetrakis(4-methoxyphenyl)-porphyrin (TMPP) and its zinc complex (ZnTMPP) on tumor levels of malondialdehyde (MDA), reduced glutathione (GSH) and cytokines, and on the activity of caspase-3 and metalloproteases (MMP-2 and -9) and attempted to correlate them with the histological alterations of tumors in 3-month-old male Wistar rats, 180 ± 20 g, bearing Walker 256 carcinosarcoma. Rats were randomly divided into five groups: group 1, ZnTMPP+irradiation (IR) 10 mg/kg body weight; group 2, TMPP+IR 10 mg/kg body weight; group 3, 5-aminolevulinic acid (5-ALA+IR) 250 mg/kg body weight; group 4, control, no treatment; group 5, only IR. The tumors were irradiated for 15 min with red light (100 J/cm², 10 kHz, 685 nm) 24 h after drug administration. Tumor tissue levels of MDA (1.1 ± 0.7 in ZnTMPP vs 0.1 ± 0.04 nmol/mg protein in control) and TNF-α (43.5 ± 31.2 in ZnTMPP vs 17.3 ± 1.2 pg/mg protein in control) were significantly higher in treated tumors than in controls. Higher caspase-3 activity (1.9 ± 0.9 in TMPP vs 1.1 ± 0.6 OD/mg protein in control) as well as the activation of MMP-2 (P < 0.05) were also observed in tumors. These parameters were correlated (Spearman correlation, P < 0.05) with the histological alterations. These results suggest that PDT activates the innate immune system and that the effects of PDT with TMPP and ZnTMPP are mediated by reactive oxygen species, which induce cell membrane damage and apoptosis.

Possible in vivo mechanisms involved in photodynamic therapy using tetrapyrrolic macrocycles.

Photodynamic therapy (PDT) mediated by oxidative stress causes direct tumor cell damage as well as microvascular injury. To improve this treatment new photosensitizers are being synthesized and tested. We evaluated the effects of PDT with 5,10,15,20-tetrakis(4-methoxyphenyl)-porphyrin (TMPP) and its zinc complex (ZnTMPP) on tumor levels of malondialdehyde (MDA), reduced glutathione (GSH) and cytokines, and on the activity of caspase-3 and metalloproteases (MMP-2 and -9) and attempted to correlate them with the histological alterations of tumors in 3-month-old male Wistar rats, 180 ± 20 g, bearing Walker 256 carcinosarcoma. Rats were randomly divided into five groups: group 1, ZnTMPP+irradiation (IR) 10 mg/kg body weight; group 2, TMPP+IR 10 mg/kg body weight; group 3, 5-aminolevulinic acid (5-ALA+IR) 250 mg/kg body weight; group 4, control, no treatment; group 5, only IR. The tumors were irradiated for 15 min with red light (100 J/cm², 10 kHz, 685 nm) 24 h after drug administration. Tumor tissue levels of MDA (1.1 ± 0.7 in ZnTMPP vs 0.1 ± 0.04 nmol/mg protein in control) and TNF-α (43.5 ± 31.2 in ZnTMPP vs 17.3 ± 1.2 pg/mg protein in control) were significantly higher in treated tumors than in controls. Higher caspase-3 activity (1.9 ± 0.9 in TMPP vs 1.1 ± 0.6 OD/mg protein in control) as well as the activation of MMP-2 (P < 0.05) were also observed in tumors. These parameters were correlated (Spearman correlation, P < 0.05) with the histological alterations. These results suggest that PDT activates the innate immune system and that the effects of PDT with TMPP and ZnTMPP are mediated by reactive oxygen species, which induce cell membrane damage and apoptosis.

The dynamics of reactive oxygen species in photodynamic therapy with tetra sulfophenyl-porphyrin.

Photodynamic therapy (PDT) is a promising therapy especially in skin cancer, using the systemic administration of a photosensitizer (PS), followed by the local irradiation of the tumor with visible light. The antitumor effects of PDT are determined especially by the generation of cytotoxic reactive oxygen species (ROS). The 5,10,15,20-tetra-sulfo-phenyl-porphyrin (TSPP) is a synthetic photosensitizer, which proved its efficiency in in vitro studies. Our study evaluates the effects of PDT with TSPP upon the tumor levels of ROS and upon the metalloproteinases 2 (MMP2) activities on Wistar male rats bearing 256 Walker carcinosarcoma in correlation with the accumulation of PS in the tumor and with the intratumor histological alterations. The evaluations were performed dynamically, at 3 hours, 6 hours, 24 hours and 14 days after the PDT with TSPP. Our results emphasize that 24 hours after the PDT with TSPP, the ROS generation increases, as revealed by protein carbonyls and malondialdehyde levels and the antioxidant capacity (hydrogen donors, thiol groups) decreases in the tumor tissue. These parameters were correlated with the appearance of the histological disorders. The MMP-2 activity increases exponentially in the 24 hours-14 days post PDT interval. PDT with TSPP offers, in vivo , consistent results regarding ROS generation, MMP2 activation and cytotoxic capacity.

[Clinico-histopathological correlations of venous wall modifications in chronic venous insufficiency]. / Corelatii clinico-histopatologice ale modificarilor parietale venoase in insuficienta venoasa cronica.

The interest manifested for the conjunctive tissue pathology leaded to the study of the structural disorder that appears in the varicose veins walls. The study is a prospective one initiated in March 2007 made on 11 patients with varicose disease hospitalized at Cluj-Napoca within Surgery Clinic no. II. The purpose of this study is to point out the histopathological modifications in the varicose venous wall (great saphenous vein cross, communicating veins, perforating veins), as well as the correlation of histopathological results with the evolutive stage of chronic vein insufficiency (CEAP classification) and with the clinical score at these patients. The histopathological (HP) results for 2 of the patients revealed hypertrophy of the media, intimal hyperplasia (stage II) corresponding to a CEAP 3. Six patients were integrated in HP stage III due to the partial intimal fibrosis corresponding to a CEAP 6 for one case, CEAP 4 one case, CEAP 3 four cases. One patient had HP stage I with CEAP 3 and two patients had HP stage IV corresponding to CEAP 5, respectively CEAP 6.