It was found that H. cordata and 2-undecanone could effectively activate the Nrf2-HO-1/NQO-1 signaling pathway, inhibit intracellular reactive oxygen species production, and thus attenuate the effects of benzo[a]pyrene (B[a]P) stimulation-induced DNA damage and inflammation; the results indicated that H. cordata is chemoprevention for lung cancer and offers protection for B[a]P stimulation-induced DNA damage and inflammation. The gene discussed is NQO1; the disease is lung cancer.