The research of natural products has allowed for the discovery of biologically relevant compounds inspired by plant secondary metabolites, which contributes to the development of many chemotherapeutic drugs used in
cancer treatment. Psidium guajava leaves present a diverse
phytochemical composition including
flavonoids, phenolics, meroterpenoids, and
triterpenes as the major bioactive constituents.
Guajadial, a
caryophyllene-based meroterpenoid, has been studied for potential anticancer effects tested in
tumor cells and animal experimental models. Moreover,
guajadial has been reported to have a mechanism of action similar to
tamoxifen, suggesting this compound as a promisor
phytoestrogen-based therapeutic agent. Herein, the anti-estrogenic action and anti-proliferative activity of
guajadial is reported. The enriched
guajadial fraction was obtained by sequential chromatographic techniques from the crude P. guajava
dichloromethane extract showing promising anti-proliferative activity in vitro with selectivity for human
breast cancer cell lines MCF-7 and MCF-7 BUS (Total Growth Inhibition = 5.59 and 2.27 µg·mL-1, respectively). Furthermore, evaluation of anti-estrogenic activity in vivo was performed demonstrating that
guajadial enriched fraction inhibited the proliferative effect of
estradiol on the uterus of pre-pubescent rats. These results suggest a relationship between anti-proliferative and anti-estrogenic activity of
guajadial, which possibly acts in
tumor inhibition through
estrogen receptors due to the compounds structural similarity to
tamoxifen.