Sonodynamically induced cell damage and membrane lipid peroxidation by novel porphyrin derivative, DCPH-P-Na(I)

Background: Ultrasonically induced cell damage and active oxygen generation with a novel porphyrin derivative DCPH-P-Na(I), were compared in the same in vitro insonation setup. Materials and Methods: Sarcoma 180 cells suspended in air-saturated PBS were exposed to ultrasound at 2 MHz for up to 60 s in the presence and absence of DCPH-P-Na(I). Cell viability was determined with the trypan blue exclusion test. Lipid peroxidation in cell membranes was estimated by measuring the amount of reactive substance produced immediately following the addition of thiobarbituric acid. Results: Significant enhancement of the rates of both ultrasonically induced cell damage and lipid peroxidation was observed in the presence of 2-8 μM DCPH-P-Na(I). Both rates correlated very well. Conclusion: The enhancement of both rates with DCPH-P-Na(I) was suppressed by 10 mM histidine. These results suggest that ultrasonically generated active oxygen plays a primary role in the ultrasonically induced cell damage in the presence of DCPH-P-Na(I).