PLE effectively alleviated imiquimod (IMQ)-induced psoriasis-like lesions, reduced psoriasis lesion area and severity index, decreased epidermal hyperplasia, ameliorated the oxidative stress-induced changes in the levels of superoxide dismutase (SOD) and malondialdehyde (MDA), and reduced the levels of the inflammatory cytokines TNF-α and IL-17A. This evidence concerns the gene SOD1 and psoriasis.