Alantolactone

Alantolactone belongs to the sesquiterpene lactones from the Compositae family, a chemical group notorious for skin sensitization.

Hapten activity. The molecule binds with free amino acids and skin proteins, triggering contact allergy. In pre-sensitized guinea pigs and in human dermatitis patients, a 1 percent patch test gave positive reactions in 4 of 25 cases.

Toxicological classification. Based on a review of German-language literature, alantolactone was classified as Category A, a significant contact allergen.

Bioactivity. Alantolactone is cytotoxic in vitro against several human cancer cell lines. It also induces endogenous detoxifying enzymes including quinone reductase, glutathione reductase, glutathione S-transferase and heme oxygenase.

The protein-binding tendency of alantolactone simultaneously explains three properties: skin sensitization, induction of detoxifying enzymes, and cytotoxicity against cancer cells.

Isoalantolactone, an isomer not separately profiled in the source literature, shows similar properties.