A Study of Phototoxicity Using the Candida Albicans Test and the Photohemolysis Test / 대한피부과학회지

Background: If phototoxic:ity can be predetermined in vitro, the information will aid in prognosticating whether or not caimpounds have a photosensitizing pczrlial. OBJECTIVE: For the evaluation of the phototoxic potentials of reral drugs, we performed the Candida albicans test and the photohemolysis test. METHODS: The Candida altiicans test is based on growth inhibtion of Candida albicans after application of the drug and ultraviolet light A( UVA ) irradiatior and the photohemolysis test is based on hemolysis of red blood cells caused by irradiation ir the presence of photosensitizing compounds. In the Candida albicans test, clear zones around the drug patches were evaluated, which means positive results for the phototoxic potential of the drugs. In the photohemolysis test, the amounts of hemolysis were evaluated by measuring the relar absorbance at 540nm using a spectrophotometer. RESULTS: In the Candida albicans test, ibuprofen, naldix acid, chlorpromazine and thiodiphenylamine showed positive results, whereas others did not the photohemolysis test, griseofulvin, ibuprofen and nalicdixic acid showed increased amounts hemolysis at UVA and ultraviolet light B(UVB) irracliation, and chlorpromazine, thiodiphenylaiair, chlorothiazide and piroxicam showed increased amounts of hemolysis at UVA irradiation only. CONCLUSION: The results showed that both methods were goodness screening tests for demonstrating the phototoxicity of therapeutic drugs.

Candida albicans test for the screening of phototoxicity in anthistamines / 대한피부과학회지

BACKGROUND: Antihistamine drugs are used widely in many conditions. Although some antihistamines may cause a photosensitive reaction,many physicians are not awae of it. OBJECTIVE: For examination of the phototoxic potential of antihistamines, we performed the Candida albiecrns test which is simple, cheap, and good for the screening of many drugs. MEHTODS: Thirty microliters of each solute of various antihistamines were applied to the Sabraud dextrose agar plate in which Candida albicans were applied diffusly. Four hours after the application, 60J/cm fo UVA was irradiated for two days. The irradiated. plates and nonirradiated control ones were incubated in a dark room for 48 hours, and examined for lear zones arround the drug, which means a positive results for the phototoxic potential of the drugs. RESULTS: Mequitazine, thiethylperazine, perphenazine and cllorromazine showed positive results, whereas others did not. An additional Candida albicans test using 0.1%, 0.01%, and 0.001% of the positive drugs revealed tht chlorpromazine, thiethylperazine aderphenazine showed positive results at 0.1%, but negative at 0.01 and 0.001%. Mequitazine was niegative at 0.1, 0.01, and 0,001%, Additional studies of the Candida albicans test using 5% and 10% of the diphenhydramine and dimenhydrinate, those were known photosensitizers but they slowed negative results at this study and revealed very weak posit,ive result in 10% diphenhydramine. CONCLUSION: A photosensitive reaction such as photoallergy and persistent light react,ion may be triggered by the phenothiazine antihistamines. Negative result in 1%, and very weak positive results in 10% diphenhydramine may be due to different mechanism of phototoxicity, or the low phototoxic potential of diphenhydrainine.

Phototoxic reaction to amidarone as studied with the mouse tail technique and the candida albicans test / 대한피부과학회지

We carried out the mouse tail technique and the Candida albicans test for the study of the phototoxic reaction to amiodarone. The mouse tail technique is based on the inflammatory response of mouse tails after systemic administration of the drug and UVA irradiation and the Candida albicans test is based on growth inhibition of Candida albicana In the mouse tail technique, following the administration of amiodarone and UVA irradia tion for 5 consecutive days, there was a significant increase(14% ) in the relative water content as compared to other control groups. In the Candida albicans test, UVA irradiation after pretreatment with amiodarone resulted in a clear Candida-free zone around the disc. The results showed that amiodarone had a phototoxic potential and that both of the methods were a good screening test for demonstrat.ing the phototoxicity of a certain drug.