Pharmacological Exploration of Hypericum Annulatum Morris Subsp . Annulatum as a Source of Novel Antineoplastic Compounds

This mini-review gives an outline of the oncopharmacological projects focused on the identification of potential anticancer agents or lead compounds from Hypericum annulatum Morris subsp. annulatum, an endemic species inhabiting the Balkan Peninsula, Sardinia, East Africa and Saudi Arabia. A total of 14 phenolic compounds (incl. five benzophenones/benzophenone glycosides, one xanthone, and eight prenylated species), incorporating the core phloroglucinol scaffold were tested using different in vitro end-points to assess their antineoplastic potential. The prenylated acylphloroglucinols have shown prominent cytotoxic effects, whereas the benzophenones and the xanthone, albeit less cytotoxic proved to exert other interesting activities, incl. cytoprotective, antioxidant and MDR-reversal effects. These findings give us reason to consider Hypericum annulatum Morris subsp. annulatum as a valuable source of potential anticancer compounds.