Effects of Black Soybean on Atherogenic Prevention in Hypercholesterolemic Rabbits and on Adhesion Molecular Expression in Cultured HAECs

Abstract

<p> The aim of the study was to investigate the effect of black soybean (BS) on the susceptibility of low-density lipoprotein (LDL) in hypercholesterolemic New Zealand white rabbits. Effects of the BS extract (BSE) and its components on monocyte adhesion of human aortic endothelial cells (HAECs), and adhesion molecule were investigated. Rabbits were divided into four groups, including control, 0.5% cholesterol with 20% casein (either with or without 0.5% vitamin E), and BS groups, all fed for 8 weeks. LDL was treated with 10 μM Cu²⁺ in vitro to determine the LDL lag time, and the vitamin E content of LDL was determined. The thickness of the tunica intima was measured on paraffin sections of thoracic aortas and aortic arches stained with Movat’s pentachrome. HAECs were pretreated with 100 μg/ml of BSE, and 10 μM of genistein, daidzein, cyanidin, and aspirin for 18 h, followed by tumor necrosis factor (TNF)-<i><span style="font-family:'Times New Roman','serif';font-size:10pt;">α</span></i> (2 ng/ml) for 6 h, after which U937 cell adhesion was determined. Adhesion molecule expression was examined using ELISAs. The LDL lag time in the BS group was similar to that in the vitamin E group, while its lag time was significantly longer than those in the control and casein groups. The ratio of the intimal area/medial area of the aortic arch of the casein group was significantly higher than those in the control, BS, and vitamin E groups. The vitamin E group had the lowest value, and was closest to the control group. The BS group exhibited a significantly decreased atheroma region in the aortic arch compared to the casein group. Pre-incubation with BSE, genistein, daidzein, cyanidin, and aspirin significantly decreased adhesion by U937 monocytic cells to TNF-<i><span style="font-family:'Times New Roman','serif';font-size:10pt;">α </span></i>stimulated HAECs. Genistein, daidzein, cyanidin, and aspirin significantly suppressed the expression of vascular cell adhesion molecule (VCAM)-1. Only genistein and aspirin significantly decreased intracellular adhesion molecule (ICAM)-1 expression compared to TNF-<i><span style="font-family:'Times New Roman','serif';font-size:10pt;">α</span></i> treatment, while no treatments had any effect on E-selectin expression. BS significantly prolonged the LDL lag time and decreased the atheroma region of the aortic arch in hypercholesterolemic rabbits, thereby exerting an antiatherosclerotic effect. Presumably, the BSE downregulate intracellular redox-dependent signaling pathways in HAECs upon TNF-<i><span style="font-family:'Times New Roman','serif';font-size:10pt;">α</span></i> stimulation through regulating NF-κB, thereby attenuating the inflammatory response in atherosclerosis. The antiatherogenic and anti-inflammatory effects of BS can be used as a nutraceutical for atherogenesis prevention. </p

Inhibitive Effects of Mulberry Leaf-Related Extracts on Cell Adhesion and Inflammatory Response in Human Aortic Endothelial Cells

“…In addition, the present results were obtained using in vitro studies and may be consistent with an in vivo model of atherogenesis similar to that reported by Enkhmaa et al [ 21 ] in which mulberry leaves suppressed the development of atherosclerotic lesions. Previously, we proved that black beans significantly prolong LDL lag time and decrease the atheroma regions of the aortic arch and thoracic aorta in hypercholesterolemic NZW rabbits [ 61 ]. We then demonstrated that black soybean extract and PSPLE significantly decreased the adhesion of U937 monocytic cells to TNF- α -stimulated HAECs and reduced adhesion molecules expression (VCAM-1 and ICAM-1) as well as NF- κ B-p65 expression [ 37 ].…”

Antioxidant Activity and Health Benefits of Anthocyanin of Black Soybeans

“…The inhibition of platelet activation is contributed by the anthocyanin, peptides, isoflavone, and adenosine. An in vivo study by Chao et al (2013) was published on the effect of black soybean as prevention of the atherogenic process in the hypercholesterolemic rabbit. Black soybean could prolong the lag time of LDL oxidation, which can inhibit LDL oxidation.…”

Natural Phenol Polymers: Recent Advances in Food and Health Applications

“…The broths from fermentation of black soybean in the presence of specific ingredients exhibited high antioxidant potency on account of the high levels of polyphenols including flavonoids and anthocyanins together with essential amino acids, which makes this material of interest for the preparation of nutritional drinks and health foods [ 129 ]. The anti-obesity, blood glucose control, cholesterol and insulin resistance lowering effects of black soybean either fermented or not were confirmed on animal models including hypercholesterolemic rabbits [ 130 ] and mice with high fat/cholesterol diet-induced obesity [ 131 , 132 ]; in addition, in ovariectomized mice, fermented black soybean supplementation lowered serum HDL-cholesterol, estradiol levels, serum alkaline phosphatase activity and osteocalcin levels, suggesting an osteoporosis preventive action [ 133 ].…”