Search

Oleacein is a polyphenol and can be found in unfiltered extra virgin olive oil and leaves Ligustrum vulgare L. (Oleaceae). The aim of the present study was to investigate whether oleacein could increase efflux cholesterol from macrophages.Oleacein in dose-dependent manner (OLEA20, OLEA50) significantly reduced lipid deposits in macrophages. The increase of SRB1 expression was found for OLEA50 and OLEA20 compared to oxLDL-induced macrophages. Oleacein significantly up-regulated protein expression of ABCA1 and ABCG1 transporter. Moreover, oleacein increased of HO-1 intracellular secretion, as well as increased activation of Nrf2. Whereas, the level of NF-κB protein was almost completely inhibited by oleacein at the same concentrations. For OLEA10, no significant changes were observed for the parameters tested.Our study demonstrated that oleacein may reduce foam cell formation. Therefore, we propose a novel explanation for the oleacein, that can be used to develop new therapeutic strategies for the treatment of atherosclerosis.

Gynostemma pentaphyllum was widely consumed in China because of its various pharmacological activities. Numerous studies have confirmed the beneficial effects of G. pentaphyllum. However, the ultimate compounds responsible for its inhibitory effects on foam cell formation were still unknown. Gypenoside LVI (GPLVI), a dammarane-type gynosaponin was isolated and identified from G. pentaphyllum. Treatment of GPLVI successfully attenuated foam cell formation, as evidenced by Oil Red O staining, TG and cholesterol contents, and Dil-ox-LDL uptake analyses. GPLVI displayed significant inhibitory effects on secretion of IL-6 and IL-1β. In contrast, production of TNF-α was not markedly reduced. GPLVI also markedly induced ABCG1, SRB1 and LXRα expression. Additionally, GPLVI significantly blocked phosphorylation of ERK and JNK. Taken together, our results suggested that GPLVI might be responsible for the inhibitory effect of G. pentaphyllum on ox-LDL-induced foam cell formation mainly by promoting cholesterol efflux and inhibiting inflammatory response.

Gynostemma pentaphyllum (Thunb.) Makino was traditionally used as antiatherogenic foods in China but ingredients responsible for the effects remained unexplored. Here, kaempferol 3-O-[2G-(E)-Coumaroyl-3G-O-β-D-glucosyl-3R-O-β-D-glucosylrutinoside] (KCGG), gypenoside XLVI (GPXLVI), gypenoside LI (GPLI), gypenoside L (GPL), ginsenoside Rd (GSRd) and 2α, 3β, 12β, 20 (S)-tetrahydroxy-25-hydroperoxy-dammar-23-ene-20-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside (GLUP) were isolated, among which KCGG, GPLI and GLUP exhibited greater antioxidant potential. The predominant inhibitory effects of KCGG, GPLI and GLUP on oxidized low-density lipoproteins (ox-LDL)-induced foam cell formation and intracellular lipid accumulation were further confirmed at non-cytotoxic concentrations. KCGG mainly decreased interleukin-6 (IL-6) production, while GPLI and GLUP were more powerful in inhibiting interleukin-1β (IL-1β) accumulation. KCGG, GPLI and GLUP significantly inhibited extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) phosphorylation. They also dramatically promoted cholesterol efflux through up-regulating scavenger receptor class B type I (SRB1) expression. In conclusion, KCGG, GPLI and GLUP acted through different pathways that acted simultaneously.

Graphical abstract Highlights • GPLVI from ethyl acetate fractions of G. pentaphyllum was a dammarane-type gynosaponin. • GPLVI inhibited ox-LDL-induced foam cell formation. • GPLVI induced a LXRα-dependent ABCG1 and SRB1 expression. • GPLVI blocked ox-LDL-induced phosphorylation of ERK and JNK. • GPLVI might be responsible for the anti-atherosclerotic effect of G. pentaphyllum. Abstract Gynostemma pentaphyllum was widely consumed in China because of its various pharmacological activities. Numerous studies have confirmed the beneficial effects of G. pentaphyllum. However, the ultimate compounds responsible for its inhibitory effects on foam cell formation were still unknown. Gypenoside LVI (GPLVI), a dammarane-type gynosaponin was isolated and identified from G. pentaphyllum. Treatment of GPLVI successfully attenuated foam cell formation, as evidenced by Oil Red O staining, TG and cholesterol contents, and Dil-ox-LDL uptake analyses. GPLVI displayed significant inhibitory effects on secretion of IL-6 and IL-1β. In contrast, production of TNF-α was not markedly reduced. GPLVI also markedly induced ABCG1, SRB1 and LXRα expression. Additionally, GPLVI significantly blocked phosphorylation of ERK and JNK. Taken together, our results suggested that GPLVI might be responsible for the inhibitory effect of G. pentaphyllum on ox-LDL-induced foam cell formation mainly by promoting cholesterol efflux and inhibiting inflammatory response. [ABSTRACT FROM AUTHOR]

• Oleacein is a secoiridoid of Olea europea L. and Ligustrum vulgare L. (Oleaceae). • Oleacein reduces lipid deposits in macrophages via SRB1 receptor and ABC transporters. • Oleacein increases HO-1 intracellular secretion. • Oleacein increases Nrf2 protein level and decreases NFkB protein level. • Oleacein could play role in the prevention of atherosclerosis. Oleacein is a polyphenol and can be found in unfiltered extra virgin olive oil and leaves Ligustrum vulgare L. (Oleaceae). The aim of the present study was to investigate whether oleacein could increase efflux cholesterol from macrophages. Oleacein in dose-dependent manner (OLEA20, OLEA50) significantly reduced lipid deposits in macrophages. The increase of SRB1 expression was found for OLEA50 and OLEA20 compared to oxLDL-induced macrophages. Oleacein significantly up-regulated protein expression of ABCA1 and ABCG1 transporter. Moreover, oleacein increased of HO-1 intracellular secretion, as well as increased activation of Nrf2. Whereas, the level of NF-κB protein was almost completely inhibited by oleacein at the same concentrations. For OLEA10, no significant changes were observed for the parameters tested. Our study demonstrated that oleacein may reduce foam cell formation. Therefore, we propose a novel explanation for the oleacein, that can be used to develop new therapeutic strategies for the treatment of atherosclerosis. [ABSTRACT FROM AUTHOR]

• Six compounds with anti-atherosclerosis effects were isolated from G. pentaphyllum. • KCGG, GPLI and GLUP exhibited greater antioxidant potency than GPXLVI, GPL and GSRd. • KCGG decreased IL-6 production, GPLI and GLUP inhibit IL-1β accumulation. • KCGG, GPLI and GLUP inhibited ERK and JNK phosphorylation. • G. pentaphyllum acted by multiple active ingredients through multi-targets. Gynostemma pentaphyllum (Thunb.) Makino was traditionally used as antiatherogenic foods in China but ingredients responsible for the effects remained unexplored. Here, kaempferol 3-O-[2G-(E)-Coumaroyl-3G-O-β-D-glucosyl-3R-O-β-D-glucosylrutinoside] (KCGG), gypenoside XLVI (GPXLVI), gypenoside LI (GPLI), gypenoside L (GPL), ginsenoside Rd (GSRd) and 2α, 3β, 12β, 20 (S)-tetrahydroxy-25-hydroperoxy-dammar-23-ene-20-O-β-D-glucopyranosyl-(1 → 6)-β-D-glucopyranoside (GLUP) were isolated, among which KCGG, GPLI and GLUP exhibited greater antioxidant potential. The predominant inhibitory effects of KCGG, GPLI and GLUP on oxidized low-density lipoproteins (ox-LDL)-induced foam cell formation and intracellular lipid accumulation were further confirmed at non-cytotoxic concentrations. KCGG mainly decreased interleukin-6 (IL-6) production, while GPLI and GLUP were more powerful in inhibiting interleukin-1β (IL-1β) accumulation. KCGG, GPLI and GLUP significantly inhibited extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) phosphorylation. They also dramatically promoted cholesterol efflux through up-regulating scavenger receptor class B type I (SRB1) expression. In conclusion, KCGG, GPLI and GLUP acted through different pathways that acted simultaneously. [ABSTRACT FROM AUTHOR]