Objective: To establish the 3T3 mouse fibroblast neutral red uptake (NRU-PT) phototoxicity test method, and evaluate the practicality of the method in detecting potential phototoxicity of the cosmetic products.
Methods: Fifteen phototoxic and 9 non-phototoxic chemicals were tested in our laboratories, the phototoxic potential of the test chemicals was evaluated in a prediction model in which either the photo irritation factor (PIF) or the mean photo effect (MPE) was compared with the coherence and sensitivity of the method. 20 kinds of functional cosmetics were detected and the results were analyzed by the 3T3 NRU-PT in vitro and Guinea pig skin phototoxicity test (in vivo).
Results: Both PIF and MPE of the chemicals were highly reproduced, and the correlation between in vitro and in vivo data was almost perfect. All the non-phototoxic provided a negative result, while 14 of the 15 phototoxic tested chemicals gave clear positive results. For cosmetics, the correlation between in vitro and in vivo data was consistent.
Conclusion: The 3T3 NRU PT test was established successfully, it should be used as a good alternative method for assessing the phototoxic potential of the chemicals and cosmetics in China.