Anticancer effect of altersolanol A, a metabolite produced by the endophytic fungus Stemphylium globuliferum, mediated by its pro-apoptotic and anti-invasive potential via the inhibition of NF-κB activity

Altersolanol A, a natural product from the endophytic fungus Stemphylium globuliferum isolated from the medicinal plant Mentha pulegium (Lamiaceae) growing in Morocco, shows cytotoxic, cytostatic, anti-inflammatory and anti-migrative activity against human chronic myeloid K562 leukemia and A549 lung cancer cells in a dose dependent manner without affecting the viability of non cancerous cells. Altersolanol A induces cell death by apoptosis through the cleavage of caspase-3 and -9 and through the decrease of anti-apoptotic protein expression. Moreover, we report here the importance of the distinct structural features of altersolanol A by testing other related anthracene derivatives in order to identify preliminary structure-activity relationships. Acetylation of altersolanol A did not improve activity where other derivatives such as tetrahydroaltersolanol B and ampelanol that differ from altersolanol A by reduction of one of a carbonyl group and removal of hydroxyl substituents were inactive in comparison. Altogether our results suggest that altersolanol A may be considered as an interesting lead for further development of chemotherapeutic agents.