Phylloquinone improves endothelial function, inhibits cellular senescence, and vascular inflammation

Area of Science:

• Biochemistry
• Cardiovascular Research
• Nutritional Science

Background:

• Vitamin K compounds, including phylloquinone (PK) and menaquinones (MK), are vital nutrients.
• Vascular dysfunction is a significant health concern, and understanding protective mechanisms is crucial.
• Previous studies suggested menaquinones possess vasoprotective properties.

Purpose of the Study:

• To investigate the vasoprotective potential of phylloquinone (PK) in various models of vascular dysfunction.
• To compare the effects of PK and MK on endothelial function, inflammation, and cellular senescence.
• To explore the vascular conversion of PK to menaquinone-4 (MK-4).

Main Methods:

• In vivo studies using ApoE/LDLR-/- mice fed with PK or MK.
• In vitro studies on isolated aorta and cultured vascular cells (endothelial and smooth muscle cells).
• Assessment of endothelial function, TNF-induced vasorelaxation, inflammation (NFκB activation), and cell senescence.

Main Results:

• Both PK and MK significantly improved endothelial function in ApoE/LDLR-/- mice over 8 weeks.
• PK and MK equally prevented TNF-induced impairment of vasorelaxation in isolated aortas.
• PK and MK demonstrated comparable anti-senescence effects by reducing DNA damage and anti-inflammatory activity via NFκB modulation in vascular cells.

Conclusions:

• Phylloquinone (PK) and menaquinones (MK) exhibit similar vasoprotective effects.
• These effects are partly attributed to the inhibition of cellular senescence and inflammation in the vascular wall.
• The vascular conversion of PK to MK-4 suggests a potential role for MK in PK's vasoprotective actions.