Abstract
To minimize the use of animals in toxicity testing, and to reduce the cost in vivo test, more rational test method was described which determines, in the same animal, photoxic and photoallergic potential of a substance, and is daptable to routine testing. The other purpose of this study was to investigate the usefulness of in vivo alternatives ; photostability and spectrophotometric carbonyl assay. In this modified photosensitization model, animal numbers and resting periods, the number and method of topical application were simplified. Two positive photoreactive agents, Benzocaine and 6-methyl coumarine, showed a similar photoallergic potential to that of Ichikawa's method. Two sunscreens, Octyl methoxy cinnamate, Butyl methoxyl dibenzoyl methane, hardly showed photoallergic potentials. The photostability test could be used in the step of prescreening of photosensitization potential because most of the photoreactive agents represented the reduction of more than 20% in the absorbance. And photoreactive agents have a high potential of photosensitization in the sddessment of spectrophotometric carbonyl level although two sunscreens have a low possibility of photosensitization. Therefore this method was assumed as a valuable in vivo alternatives in the respect even in the very low concentrations which phototoxicity test using almonella showed no phototoxic potential.
동물시험을 최소화 하고, 동물시험에 사용되는 노력과 비용을 줄이기 위해 동일한 동물에서 광독성과 광알러지성을 함께 보는 새로운 방법을 제안하고, in vitro alternatives로서 photostability와 spectrophotometric carbonyl assay의 유용성을 검토하였다. Modified photosensitization model에서는 Ichikawa 방법과는 달리 동물수, 휴식 기간, 첩포 횟수를 단순히하고 폐쇄 첩포를 추가하였다. 방법의 유용성을 보기 위해 Benzocaine, 6-methyl coumarine을 Ichikawa 방법 및 본 시험 방법으로 결과를 비교한 결과 macroscopic, histologic examination에서 비슷한 결과를 얻었다. Photostability 시험에서는 pbotoreactive agent 들이 모두 20%이상의 흡광도 감소를 보여 pbotosensitization potential을 측정하기 위한 전 단계 실험으로서의 가능성을 보여주었고, spectrophotometric carbonyl assay에서는 salmonella를 이용한 광독성 실험에서는 나타나지 않았던 저농도의 Amthracene, Hematoporphyrin에서 조차도 phtotoxic prtential을 보여주어 in vitro alternatives로서의 가능성을 보여주었다.
