Prevention of Fine Dust-Induced Vascular Senescence by Humulus lupulus Extract and Its Major Bioactive Compounds

Abstract

Both short- and long-term exposure to fine dust (FD) from air pollution has been linked to various cardiovascular diseases (CVDs). Endothelial cell (EC) senescence is an important risk factor for CVDs, and recent evidence suggests that FD-induced premature EC senescence increases oxidative stress levels. Hop plant (Humulus lupulus) is a very rich source of polyphenols known to have nutritional and therapeutic properties, including antioxidant behavior. The aims of this study were to evaluate whether Humulus lupulus extract prevents FD-induced vascular senescence and dysfunction and, if so, to characterize the underlying mechanisms and active components. Porcine coronary arteries and endothelial cells were treated with FD in the presence or absence of hop extract (HOP), and the senescence-associated-beta galactosidase (SA-β-gal) activity, cell-cycle progression, expression of senescence markers, oxidative stress level, and vascular function were evaluated. Results indicated that HOP inhibited FD-induced SA-β-gal activity, cell-cycle arrest, and oxidative stress, suggesting that HOP prevents premature induction of senescence by FD. HOP also ameliorated FD-induced vascular dysfunction. Additionally, xanthohumol (XN) and isoxanthohumol (IX) were found to produce the protective effects of HOP. Treatment with HOP and its primary active components XN and IX downregulated the expression of p22phox, p53, and angiotensin type 1 receptor, which all are known FD-induced redox-sensitive EC senescence inducers. Taken together, HOP and its active components protect against FD-induced endothelial senescence most likely via antioxidant activity and may be a potential therapeutic agent for preventing and/or treating air-pollution-associated CVDs.

Taxifolin as a Major Bioactive Compound in the Vasorelaxant Effect of Different Pigmented Rice Bran Extracts

“…Epidemiological studies have indicated that regular intake of polyphenol-rich diets, such as red wine and tea, is associated with the prevention of cardiovascular diseases. It has also been proposed that certain polyphenolic-rich products and authentic polyphenols can increase the protective effect of these phytochemicals on the vascular system, especially on the endothelium ( Hertog et al, 1993a ; Hertog et al, 1993b ; Hertog et al, 1997 ; Oak et al, 2018 ; Shiwakoti et al, 2020 ). Indeed, several polyphenol-rich plant and fruit extracts derived from grape, tea, berries, and traditional medicinal plants cause pronounced endothelium-dependent vasorelaxations of pre-contracted arterial rings ( Fitzpatrick et al, 1995 ; Shiwakoti et al, 2020 ).…”

“…It has also been proposed that certain polyphenolic-rich products and authentic polyphenols can increase the protective effect of these phytochemicals on the vascular system, especially on the endothelium ( Hertog et al, 1993a ; Hertog et al, 1993b ; Hertog et al, 1997 ; Oak et al, 2018 ; Shiwakoti et al, 2020 ). Indeed, several polyphenol-rich plant and fruit extracts derived from grape, tea, berries, and traditional medicinal plants cause pronounced endothelium-dependent vasorelaxations of pre-contracted arterial rings ( Fitzpatrick et al, 1995 ; Shiwakoti et al, 2020 ). After confirming the strong vasodilatory effect of RRBE among the different pigmented RBEs evaluated, we hypothesized that observed effects were due to relatively high contents of polyphenol in RRBE compared to others.…”

“…Nevertheless, many studies have recently suggested that polyphenols, such as phenolic acid, anthocyanin, and proanthocyanidin, are major antioxidants in rice ( Min et al, 2011 ). Plant polyphenols have been shown to improve vascular function by directly acting as an antioxidant in interacting with reactive oxygen species like superoxide, hydroxy, and peroxy radicals or by activation of endothelial NO synthase (eNOS) through phosphoinositide-3 kinase (PI3K)/Akt pathway ( Oak et al, 2018 ; Shiwakoti et al, 2020 ). Thus, with increasing interest in health worldwide, various pigmented rice including black, red, brown, and green, is being consumed for its natural antioxidant properties.…”

Xanthohumol from Hop: Hope for cancer prevention and treatment

“…XN is a prenylated flavonoid extracted from the Hop plant Humulus lupulus L., (Figure 1a) which form an essential ingredient of beer. [63][64][65] XN exists ubiquitously in the Hop plant and is a component of the secreted resin from female inflorescences and through the glandular trichromes present on the cone bracts of hop plants. 63,66 The young leaves of the Hop plant also form as the source for XN.…”

“…Xanthohumol (XN) is one such agent that has high potential in the prevention and treatment of several diseases, including cancer. XN is a prenylated flavonoid extracted from the Hop plant Humulus lupulus L., (Figure 1a) which form an essential ingredient of beer 63–65 . XN exists ubiquitously in the Hop plant and is a component of the secreted resin from female inflorescences and through the glandular trichromes present on the cone bracts of hop plants 63,66 .…”