Gut microbiota-derived isoxanthohumol metabolite, 8-prenylnaringenin, mitigates endothelial dysfunction in Angiotensin II-induced hypertension through G protein-coupled estrogen receptor-mediated eNOS activation.

8-PN increased eNOS phosphorylation at Ser1177 and NO production in endothelial cells through GPER-mediated Ca2+-dependent signaling.

• The Ca2+-dependent pathway involved phosphorylation of Ca2+/calmodulin-dependent protein kinase β (CaMKKβ) and AMP-activated protein kinase (AMPK).
• The effect was mediated through the Gβγ subunit of GPER.
• 8-PN is a phytoestrogen derived from isoxanthohumol via gut microbiota conversion.
• In vitro endothelial cell assays were used to characterize the signaling cascade.

8-PN activated eNOS through a second GPER-mediated pathway involving EGFR transactivation and c-Src-facilitated PI3K/Akt and ERK phosphorylation.

• c-Src was identified as a facilitator of phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) and extracellular signal-related kinase (ERK) phosphorylation.
• EGFR activation was downstream of GPER signaling in this second pathway.
• Both eNOS phosphorylation pathways were mediated through the Gβγ subunit.
• The dual GPER-dependent pathways were characterized using in vitro endothelial cell assays.

Molecular docking analysis indicated that 8-PN can bind to GPER and facilitate activation of downstream signaling cascades.

• Molecular docking was used to support the mechanistic findings from cell-based assays.
• The docking results were consistent with the functional data showing GPER-mediated effects of 8-PN.
• 8-PN is described as a potent phytoestrogen, consistent with its ability to interact with estrogen receptors including GPER.

8-PN attenuated Angiotensin II-induced endothelial dysfunction and induced vasorelaxation in vivo in a mouse model.

• An in vivo mouse model of Angiotentin II (Ang II)-induced endothelial dysfunction was used.
• Ex vivo isolated artery preparations were also used to assess vasorelaxation.
• 8-PN stimulated eNOS phosphorylation and NO production in vivo consistent with in vitro findings.
• The in vivo results supported the potential of 8-PN as a therapeutic candidate for endothelial dysfunction-related vascular diseases.

8-PN is a gut microbiota-derived metabolite formed from isoxanthohumol, found in Humulus lupulus L. (hops), a botanical source used traditionally in brewing.

• Humulus lupulus L. is described as 'a rich botanical source of prenylated flavonoids with potential cardiovascular protective properties.'
• 8-PN is characterized as 'a potent phytoestrogen formed from isoxanthohumol by the gut microbiota.'
• Isoxanthohumol is the precursor compound present in hops that is converted to 8-PN by gut microbial metabolism.
• The cardiovascular protective properties of hop-derived prenylated flavonoids provided the rationale for investigating 8-PN in vascular health.