Fraxinellone: From pesticidal control to cancer treatment.

Fraxinellone (FRA) is a degraded limonoid isolated from the root bark of Dictamnus plants. The potent insecticidal activity of FRA has led to the synthesis of numerous derivatives (presented here with the structure-activity relationships) active against the oriental armyworm Mythimna separata Walker. In addition to its pesticidal activity, the natural product displays potent anti-inflammatory and immuno-modulatory effects at the origin of hepatoprotective and anticancer properties. This mini-review provides an update of the mechanism of action of FRA to highlight the recently discovered capacity of the compound to deactivate cancer-associated fibroblasts and thus to limit the immunosuppressive tumor microenvironment. The anticancer mode of action of FRA raises new ideas to better understand its primary insecticidal activity. The relationship between drug-induced cancer cell death and insect cell death is discussed. A drug interaction with the insect cytokine growth-blocking peptide (GBP), a member of the large EGF family, is proposed, supported by preliminary molecular modeling data. Altogether, the review shed light on the pharmacological properties of fraxinellone as an antitumor agent and a natural insecticide.