Carob Pod Insoluble Fiber Exerts Anti-Atherosclerotic Effects in Rabbits through Sirtuin-1 and Peroxisome Proliferator-Activated Receptor-γ Coactivator-1α

Abstract

The aim of this study was to evaluate the potential effects of an insoluble dietary fiber from carob pod (IFC) (1 g ⋅ kg(-1) ⋅ d(-1) in the diet) on alterations associated with atherosclerosis in rabbits with dyslipidemia. Male New Zealand rabbits (n = 30) were fed the following diets for 8 wk: 1) a control diet (SF412; Panlab) as a control group representing normal conditions; 2) a control supplemented with 0.5% cholesterol + 14% coconut oil (DL) (SF302; Panlab) for 8 wk as a dyslipidemic group; and 3) a control containing 0.5% cholesterol + 14% coconut oil plus IFC (1 g ⋅ kg(-1) ⋅ d(-1)) (DL+IFC) for 8 wk. IFC was administered in a pellet mixed with the DL diet. The DL-fed group developed mixed dyslipidemia and atherosclerotic lesions, which were associated with endothelial dysfunction, inflammation, and fibrosis. Furthermore, sirtuin-1 (SIRT1) and peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) protein expression in the aorta were reduced to 77% and 63% of the control group, respectively (P < 0.05), in these rabbits. Administration of IFC to DL-fed rabbits reduced the size of the aortic lesion significantly (DL, 15.2% and DL+IFC, 2.6%) and normalized acetylcholine-induced relaxation (maximal response: control, 89.3%; DL, 61.6%; DL+IFC, 87.1%; P < 0.05) and endothelial nitric oxide synthase expression (DL, 52% and DL+IFC, 104% of the control group). IFC administration to DL-fed rabbits also reduced cluster of differentiation 36 (DL, 148% and DL+IFC, 104% of the control group; P < 0.05), plasminogen activator inhibitor-1 (DL, 141% and DL+IFC, 107% of the control group), tumor necrosis factor-α (DL, 166% and DL+IFC, 120% of the control group), vascular cell adhesion molecule-1 (DL, 153% and DL+IFC, 110% of the control group), transforming growth factor-β (DL, 173% and DL+IFC, 99% of the control group), and collagen I (DL, 157% and DL+IFC, 112% of the control group) in the aorta. These effects were accompanied by an enhancement of SIRT1 and PGC-1α (160% and 121% of the control group, respectively; P < 0.05) vascular expression. In summary, we demonstrated for the first time, to our knowledge, that administration of IFC reduces the development of atherosclerosis in rabbits. This effect seems to be related to an improvement in endothelial function and a reduction of inflammation and fibrosis, most probably as a consequence of the reduction of serum concentrations of cholesterol and triglycerides. Increased expression of aortic SIRT1 and PGC-1α could play an important role in the observed effects of IFC in rabbits with dyslipidemia.

Carob pods (Ceratonia siliqua L.) improve growth performance, antioxidant status and caecal characteristics in growing rabbits

“…To do this, flavonoids increase LDL receptor densities in liver by binding to apolipoprotein B (El‐Beshbishy et al., ). Moreover, carob fibre and polyphenol‐rich preparations have shown good potential for a diverse variety of health benefits, including reduction in LDL in hypercholesterolaemic patients, beneficial effect on body weight and improved digestion and lipid utilization (Valero‐Muntildoz et al., ; Nasar‐Abbas et al., ). Treatment with carob pods prevented the lipid peroxidation by enhancing the SOD, CAT and GPx activities.…”

Functional Components of Carob Fruit: Linking the Chemical and Biological Space

“…Carob powder could be a potential candidate in diet regimen of obese and overweight persons. Valero-Munoz et al observed that carob pod fibers suppressed physiological events that led to atherosclerosis in rabbits with dyslipidemia [96]. They observed that the expression of SIRT1 and PGC-1a, proteins with a key role in the vascular and metabolic system, were enhanced, proposing a new mechanism of action of carob components.…”

Degree of roasting of carob flour affecting the properties of gluten-free cakes and cookies

“…In fact, the carob fibre can be used to minimize the lipid oxidation in cookies; in a similar way that tocopherol does (Haber 2002). Several studies have also reported a cholesterol attenuation activity of this carob fibre (Ruiz-Roso et al 2010;Zunft et al 2003), an antiatherosclerotic effect of carob pod insoluble fibre in rabbits (Valero-Muñoz et al 2014) and even a carob pod treatment for acute-onset diarrhea has been proposed (Loeb et al 1989). Added to that, carob is also rich in D-pinitol, a compound that can lower blood glucose and has antiinflammatory effects (Tetik et al 2011).…”