The growing interest in alternative medicines, including traditional medicinal plants, has caused some health concerns due to poor awareness in the general population of the possible side effects from inappropriate practices. Psoralea corylifolia L. has been used in Chinese and Indian traditional medicine for the treatment of various inflammatory diseases of the skin and to improve vitality. Our data show that the extract obtained from the seeds of Psoralea corylifolia L. decreased mitochondrial complex I and proteasome activities; and oxidative stress might be an early event.