Pseudohypericin is isolated and purified from the herbs of Hypericum perforatum L.Pseudohypericin has photocytotoxic, and antiretroviral activities, it has potential therapeutic value in diseases such as AIDS. Pseudohypericin can inhibit LPS-stimulated PGE2 and NO in mouse macrophages by potentiating suppressor of cytokine signaling 3 (SOCS3) expression, it has anti-tumor potential.