Research in Pharmaceutical Sciences

ORIGINAL ARTICLE
Year
: 2019  |  Volume : 14  |  Issue : 3  |  Page : 190--200

Siamese neem flower extract suppresses cholesterol absorption by interfering NPC1L1 and micellar property in vitro and in intestinal Caco-2 cells


Acharaporn Duangjai1, Atcharaporn Ontawong2, Chutima Srimaroeng4 
1 Division of Physiology, School of Medical Sciences, University of Phayao, Phayao, Thailand
2 Division of Physiology, School of Medical Sciences, University of Phayao, Phayao; Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand

Correspondence Address:
Chutima Srimaroeng
Department of Physiology, Faculty of Medicine, Chiang Mai University, Chiang Mai
Thailand

Siamese neem (Azadirachta indica A. Juss var. siamensis Valeton) (A. indica) leaf extract, a traditional ayurvedic medicine, has been reported to exhibit antipyretic, antibacterial, antidyslipidemic, and antihyperglycemia effects. This study investigated the mechanism of hypocholesterolemic effect of methanolic extract of Siamese neem flowers in in vitro studies and in Caco-2 cells. Pancreatic cholesterol esterase and 3-hydroxy 3-methylglutaryl-CoA (HMG-CoA) reductase activities were assessed. Cholesterol micelle formation was prepared for in vitro cholesterol physicochemical property analyses, micelle size and solubility, and transport of cholesterol into the Caco-2 cells. The expression of niemann-pick C1 like 1 (NPC1L1), and its major regulator, peroxisome proliferator-activated receptor δ (PPARδ), were determined by western blot and real time polymerase chain reaction, respectively. A. indica flower extract inhibited pancreatic cholesterol esterase activity and increased cholesterol micelles size. Uptake of cholesterol into Caco-2 cells was inhibited by A. indica flower extract in a dose-dependent manner. In addition, A. indica extract inhibited HMG-CoA reductase activity, resulting in low level of intracellular cholesterol accumulation, together with increased cytosolic NPC1L1 protein expression and decreased PPARδ gene expression. In conclusion, A. indica flower extract has cholesterol-lowering effects by inhibiting intestinal cholesterol absorption, interfering micellar cholesterol formation, and attenuating cholesterol synthesis. As such, A. indica flower extract has potential for developing into nutraceutical product for prevention of hypocholesterolemia.


How to cite this article:
Duangjai A, Ontawong A, Srimaroeng C. Siamese neem flower extract suppresses cholesterol absorption by interfering NPC1L1 and micellar property in vitro and in intestinal Caco-2 cells.Res Pharma Sci 2019;14:190-200


How to cite this URL:
Duangjai A, Ontawong A, Srimaroeng C. Siamese neem flower extract suppresses cholesterol absorption by interfering NPC1L1 and micellar property in vitro and in intestinal Caco-2 cells. Res Pharma Sci [serial online] 2019 [cited 2019 Sep 17 ];14:190-200
Available from: http://www.rpsjournal.net/article.asp?issn=1735-5362;year=2019;volume=14;issue=3;spage=190;epage=200;aulast=Duangjai;type=0