Phototoxicity activity of Psoralea drupacea L. using Atremia salina bioassay system

Objective: Phototoxicity is a kind of dermatitis that is activated by exposure to ultraviolet light following the administration of some drugs or natural products. Artemia salina (A. salina) (brine shrimp) has been effectively applied for toxicity testing and is perfect for biological screening of many chemicals for simultaneous evaluation of toxicity and phototoxicity. The objective of this study was to investigate the phototoxic activitiy of the methanolic extract and chloroform and CH3OH/H2O2 fraction of Psoralea drupacea (P. drupacea). Materials and methods: The phototoxic effect of the methanolic extract, chloroform and CH3OH/H2O2 fractions of P. drupacea was evaluated using A. salina bioassay system. Different concentrations of methanolic extract and fractions of P. drupacea were added to the plate of one-day old larvae followed by exposure to UV radiation at 366 nm in three different exposure times (0, 4 and 20 h). Mortality was determined 24h after the start of the irradiation. Results: The value of LC50 of P. drupacea methanolic extract and methoxalen as positive control were 0.64 and 3.5x10^-4 mg/ml, respectively. P. drupacea methanolic extract and chloroform fraction demonstrated phototoxic activity after 4 h radiation. Conclusion: The result showed that P. drupacea methanolic extract and chloroform fraction have phototoxicity in A. salina bioassay system and their toxic effect is related to phototoxic constituents such as psoralen.