Helenalin is a selective inhibitor of transcription factor NF-κB by direct targeting of p65. It is an anti-inflammatory sesquiterpene lactone compound with alkylating activity. Through its ability to target the cysteine sulfhydryl groups in the p65 subunit of NF-κB, helenalin effectively inhibits its DNA binding.

After 80 minutes, Helenalin (10 μM; 20-120 minutes) induces complete inhibition of NF-κB DNA binding [1]. Helenalin, the anti-inflammatory and anti-carcinogenic phytochemicals, is an effective inhibitor of periodic Skp2 accumulation which is an F-box protein mediating SCF E3 ligase ubiquitylation and degradation of both CKIs during S phase progression[3].

To immature male ICR mice, Helenalin (25 mg/kg; i.p.; 6 to 12 hours) administers, induced a rapid reduction in hepatic glutathione levels[2].