Biocompatibility and antibacterial activity of photolytic products of sulfonamides
Related Experiment Video
Updated: May 5, 2026

LED-Based In Vitro Screening for Assessing Photoactivable Molecules in Bacterial Photodynamic Inactivation
Published on: January 24, 2025
Katrin Zessel1, Siegrun Mohring2, Gerd Hamscher2
1Institute of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, Foundation, Buenteweg 17, 30559 Hannover, Germany.
Background:
This study assessed the photochemical fate of nine sulfonamides (sulfamerazine, sulfanilamide, sulfamethoxypyridazine, sulfamethoxazole, sulfachloropyridazine, sulfamethazine, sulfadiazine, sulfathiazole and sulfadimethoxine) during a 6h irradiation period with UVA/UVB-light and UVA-light and over 7 days under natural (sunlight) conditions. The cell growth inhibition effect and cytotoxicity of sulfonamides and their photodegradation products was investigated over 24 and 48 h with murine fibroblasts and keratinocytes. Antibacterial activity of the degradation products was studied using the Geobacillus stearothermophilus var. Calidolactis C953 assay.
Results:
UVA/UVB treatment of several sulfonamide solutions results in degradation of the compounds in different amounts with the highest degradation rate for sulfathiazole and sulfanilamide. The UVA/UVB light degradation products exhibit no antimicrobial activity. Sun light exposure over 7 days reveals a similar degradation pattern of the different sulfonamides, albeit to a different extent. Compared with UVA/UVB-irradiation, UVA-irradiated sulfonamides degrade to a lesser extent (except sulfamethazine). There was no impact on cell toxicity of the UVA/UVB-degrading products except for sulfanilamide, while a slight impact on cell proliferation was observed.
Conclusions:
All studied sulfonamides undergo photodegradation under UV-light exposure to a greater or lesser extent. The degradation products have no cytotoxic potential except sulfanilamide and have a slight impact on cell proliferation. All degradation products showed no antibacterial activity. Thus, UV-light exposure seems to represent an adequate method for inactivating sulfonamides with regard to their antimicrobial activity.
More Related Videos
09:29In Vivo Investigation of Antimicrobial Blue Light Therapy for Multidrug-resistant Acinetobacter baumannii Burn Infections Using Bioluminescence Imaging
Published on: April 28, 2017
08:25Inactivation of Pathogens via Visible-Light Photolysis of Riboflavin-5′-Phosphate
Published on: April 6, 2022
Related Concept Videos
Combined Effects of Drugs: Synergism
Such synergistic combinations...
Inhibitors of Bacterial DNA Synthesis
Aryldiazonium Salts to Azo Dyes: Diazo Coupling
Inhibitors of Bacterial Protein Synthesis
Antimicrobial Effectiveness