Non-animal photosafety screening for complex cosmetic ingredients with photochemical and photobiochemical assessment tools

Reactive oxygen species (ROS) assay-based photosafety screening for complex ingredients: Modification of the ROS assay protocol

“…On the basis of the previous studies and literature searches (Onoue et al, 2017(Onoue et al, , 2009Onoue and Tsuda, 2006;Onoue et al, 2013b, EFSA, 2012EMA, 2021;IFRA, 2021;Nishida et al, 2015), 20 plant extracts and 44 chemicals were selected as model substances (Table 1). To clarify the impact of MW of test materials on prediction accuracy of the ROS assay, chemicals with various MW ranging from 60 to 606 were used as test chemicals.…”

“…Two chemicals and 8 plant extracts were employed as model phototoxic substances referring to the globally-accepted International Fragrance Association (IFRA) standards (IFRA, 2021), and 32 chemicals and 3 plant extracts were also selected according to the previous reports (Onoue et al, 2017(Onoue et al, , 2009Onoue and Tsuda, 2006;Onoue et al, 2013b, EFSA, 2012EMA, 2021). As reported previously (Onoue et al, 2013b, Nishida et al, 2015, 10 chemicals and 9 plant extracts were defined as non-phototoxic materials. Thus, 44 chemicals, including 34 phototoxic and 10 non-phototoxic chemicals, and 20 complex materials (plant extracts), including 11 phototoxic and 9 nonphototoxic materials, were selected for the present study.…”

“…In the validated protocol of the ROS assay (Onoue et al, 2013a(Onoue et al, , 2014, a molar concentration is employed as a unit of the test chemical concentration, and the photoreactivity of test chemicals is judged on the basis of ROS generation from test chemicals at a concentration of 200 μM on exposure to simulated sunlight. In our previous study, the mass concentration (μg/mL) was tentatively employed as the concentration unit, and then the ROS assay was applied to 11 phototoxic and 9 non-phototoxic plant extracts or oils at a chemical concentration of 50 μg/mL (Nishida et al, 2015). All the phototoxic chemicals tested were correctly identified as photoreactive, and the phototoxic potential of complex materials was also partially evaluable in the ROS assay at the concentration of 50 μg/mL.…”

Comparison of in chemico skin sensitization methods and development of an in chemico skin photosensitization assay

“…A high correlation between in vivo test outcome and NRU 3T3 PT assay predictions was established (Ceridono et al, 2012). UV-VIS light spectra analysis to check the light absorption pattern as well as measurement of singlet oxygen using ROS (reactive oxygen species) assays has been suggested to evaluate the photosensitive nature of test chemicals (Nishida et al, 2015). However, these are indirect approaches that do not address the MIE or any KE involved in the sensitization AOP.…”

TG 495: Ros (Reactive Oxygen Species) Assay for Photoreactivity

“…Based on the data currently available, the ROS assay was shown to be applicable to test chemicals covering a variety of organic functional groups, reaction mechanisms, phototoxic potency (as determined in in vivo studies) and physicochemical properties. Limited information is currently available on the applicability of the ROS assay to multi-constituent chemicals/mixtures (27). When considering testing of mixtures, difficult to test chemical (e.g.…”