Ethanolic extracts of Brazilian red propolis increase ABCA1 expression and promote cholesterol efflux from THP-1 macrophages

• Published in: Phytomedicine (Stuttgart) Vol. 19; no. 5; pp. 383 - 388
• Main Authors: Iio, Akio, Ohguchi, Kenji, Maruyama, Hiroe, Tazawa, Shigemi, Araki, Yoko, Ichihara, Kenji, Nozawa, Yoshinori, Ito, Masafumi
• Format: Journal Article
• Language: English
• Published: Germany Elsevier GmbH 15.03.2012; Urban & Fischer Verlag
• Subjects: ABCA1-expression; Animals; Apolipoprotein A-I - drug effects; Apolipoprotein A-I - metabolism; ATP Binding Cassette Transporter 1 - genetics; ATP Binding Cassette Transporter 1 - metabolism; Biological Transport - drug effects; Cattle; Cell Line; Cell Survival - drug effects; Cholesterol; Cholesterol - metabolism; Cholesterol efflux; Health aspects; Humans; Liver X Receptors; LXRα; Macrophages; Macrophages - drug effects; Macrophages - metabolism; Materia medica, Vegetable; Models, Biological; Orphan Nuclear Receptors - drug effects; Orphan Nuclear Receptors - genetics; Physiological aspects; Plant extracts; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plant Extracts - pharmacology; PPAR gamma - drug effects; PPAR gamma - genetics; PPARγ; Promoter Regions, Genetic - drug effects; Promoter Regions, Genetic - genetics; Propolis - chemistry; Red propolis; RNA, Messenger - genetics; RNA, Messenger - metabolism; Transcription, Genetic - drug effects; Japan; Red propolis; LXRα; ABCA1-expression; PPARγ; Cholesterol efflux
• ISSN: 0944-7113; 1618-095X
• DOI: 10.1016/j.phymed.2011.10.007

The ATP-binding cassette transporter A1 (ABCA1) is a membrane transporter that directly contributes to high-density lipoprotein (HDL) biogenesis by regulating the cellular efflux of cholesterol. Since ABCA1 plays a pivotal role in cholesterol homeostasis and HDL metabolism, identification of a novel substance that is capable of increasing its expression would be beneficial for the prevention and therapy of atherosclerosis. In the present study, we studied the effects of ethanolic extracts of Brazilian red propolis (EERP) on ABCA1 expression and cholesterol efflux in THP-1 macrophages. EERP enhanced PPARγ and liver X receptor (LXR) transcriptional activity at 5–15μg/ml, which was associated with upregulation of PPARγ and LXRα expression. It was also found that EERP increase the activity of the ABCA1 promoter, which is positively regulated by LXR. Consistent with these findings, treatment with EERP increased both mRNA and protein expression of ABCA1. Finally, EERP upregulated ApoA-I-mediated cholesterol efflux. Our results showed that EERP promote ApoA-I-mediated cholesterol efflux from macrophages by increasing ABCA1 expression via induction of PPARγ/LXR.