The beneficial effects of the Lab4 probiotic consortium in atherosclerosis

Background Cardiovascular disease (CVD) is currently the leading cause of mortality world-wide, responsible for approximately one-third of all global deaths. Atherosclerosis, the primary cause of CVD, is a chronic inflammatory disease characterised by lipid accumulation in the arterial wall. Despite the success of current therapies, the incidence of CVD continues to rise and the search continues for alternative therapeutic agents. The Lab4, Lab4b and CUL66 probiotic consortia have been shown to possess lipid-lowering and immunomodulatory capabilities, highlighting their anti-atherogenic potential. The aim of this project was to assess the anti-atherogenic effects of Lab4, Lab4b and CUL66 probiotic consortia using in vitro and in vivo model systems. Results Experiments using in vitro model systems demonstrated probiotic-induced attenuation of macrophage foam cell formation at the cellular and molecular levels. In addition, probiotics reduced monocyte migration, increased phagocytosis, and reduced proliferation of key atherosclerosis-associated cell types. Mice supplemented with a live combination of Lab4 and CUL66 demonstrated reduced atherosclerotic plaque formation, and an improved plasma lipid profile compared to the control. In addition, numbers of macrophages and T-cells were reduced in both the plaque and the bone marrow of probiotic-treated mice. Liver gene expression analysis revealed probiotic-induced attenuation of several key pro-atherogenic genes. Conclusion Findings from this study demonstrate many anti-atherogenic effects of Lab4, Lab4b and CUL66 probiotic consortia in both in vitro and in vivo model systems, and highlight their potential as candidates for inclusion in clinical trials and future atherosclerosis intervention strategies. Underlying mechanisms of action have also been investigated and proposed, thereby contributing to the understanding of probiotic action

Nutraceuticals in the prevention and treatment of Atherosclerosis

Objectives: To investigate the effects of nutraceuticals on key processes associated with atherosclerosis in vitro and in vivo. Background: Atherosclerosis is an inflammatory disease of the vasculature in which macrophages play key roles at all stages and represent promising therapeutic targets. Unfortunately, current therapies against atherosclerosis are not fully effective and associated with other issues such as adverse side effects. In addition, there have been many failures on pharmaceutical agents identified from drug discovery programs. Nutraceuticals represent promising alternatives in the prevention and treatment of atherosclerosis but requires a thorough understanding of their actions together with the underlying mechanisms. The purpose of this study was to address this with emphasis on key macrophage processes associated with atherosclerosis. Methods: A combination of macrophage cell lines and primary cultures were used with gene expression analysed by atherosclerosis profiler arrays and real time quantitative PCR. Foam cell formation was investigated by following the uptake of fluorescently labeled modified LDL, intracellular lipid profiling and cholesterol efflux assays. Inflammasome activation was evaluated by following the release of interleukin (IL)-1beta using an ELISA and ROS production using a kit from Abcam. The effects in vivo were analysed in C57BL/6 mice fed a high fat diet. Results: The studies focused on polyphenols, flavanols and omega-6 polyunsaturated fatty acids. These either inhibited or had no effect on several key macrophage processes associated with atherosclerosis such as pro-inflammatory gene expression, the uptake of modified LDL, macropinocytosis, ROS production and the activation of the inflammasome. In addition, where analysed, the nutraceutical inhibited several atherosclerosis-associated markers in mice fed a high fat diet. The mechanisms underlying such actions will be presented. Conclusions: The studies provide new insights into the beneficial actions of nutraceuticals in atherosclerosis

The Lab4P consortium of probiotics attenuates atherosclerosis in LDL receptor deficient mice fed a high fat diet and causes plaque stabilization by inhibiting inflammation and several pro-atherogenic processes

Scope Previous studies showed that Lab4 probiotic consortium plus Lactobacillus plantarum CUL66 (Lab4P) reduced diet-induced weight gain and plasma cholesterol levels in C57BL/6J mice fed a high fat diet (HFD). The effect of Lab4P on atherosclerosis is not known and was therefore investigated. Methods and results Atherosclerosis-associated parameters were analyzed in LDL receptor deficient mice fed HFD for 12 weeks alone or supplemented with Lab4P. Lab4P increased plasma HDL and triglyceride levels and decreased LDL/VLDL levels. Lab4P also reduced plaque burden and content of lipids and macrophages, indicative of dampened inflammation, and increased smooth muscle cell content, a marker of plaque stabilization. Atherosclerosis arrays showed that Lab4P altered the liver expression of 19 key disease-associated genes. Lab4P also decreased the frequency of macrophages and T-cells in the bone marrow. In vitro assays using conditioned media from probiotic bacteria demonstrated attenuation of several atherosclerosis-associated processes in vitro such as chemokine-driven monocytic migration, proliferation of monocytes and macrophages, foam cell formation and associated changes in expression of key genes, and proliferation and migration of vascular smooth muscle cells. Conclusion This study provides new insights into the anti-atherogenic actions of Lab4P together with the underlying mechanisms and supports further assessments in human trials

Protective effects of a unique combination of nutritionally active ingredients on risk factors and gene expression associated with atherosclerosis in C57BL/6J mice fed a high fat diet

Atherosclerosis, an inflammatory disorder of the vasculature and the underlying cause of cardiovascular disease, is responsible for one in three global deaths. Consumption of active food ingredients such as omega-3 polyunsaturated fatty acids, flavanols and phytosterols have many beneficial effects on cardiovascular disease. However, their combined actions on risk factors for atherosclerosis remains poorly understood. We have previously shown that a formulation containing each of these active components at physiologically relevant doses modulated several monocyte/macrophage processes associated with atherosclerosis in vitro, including inhibition of cytokine-induced pro-inflammatory gene expression, chemokine-driven monocyte migration, expression of M1 phenotype markers, and promotion of cholesterol efflux. The objective of the present study was to investigate whether the protective actions of the formulation extended in vivo and to delineate the potential underlying mechanisms. The formulation produced several favourable changes, including higher plasma levels of HDL and reduced levels of macrophages and myeloid-derived suppressor cells in the bone marrow. The mRNA expression of liver-X-receptor-α, peroxisome proliferator-activated receptor-γ and superoxide dismutase-1 was induced in the liver and that of interferon-γ and the chemokine (C-X-C motif) ligand 1 decreased, thereby suggesting potential mechanisms for many beneficial effects. Other changes were also observed such as increased plasma levels of triglycerides and lipid peroxidation that may reflect potential activation of brown fat. This study provides new insights into the protective actions and the potential underlying mechanisms of the formulation in vivo, particularly in relation to risk factors together with changes in systemic inflammation and hepatic lipid alterations associated with atherosclerosis and metabolic syndrome, and supports further assessments in human trials

Anti-Atherogenic actions of the Lab4b consortium of probiotics in vitro

Probiotic bacteria have many protective effects against inflammatory disorders, though the mechanisms underlying their actions are poorly understood. The Lab4b consortium of probiotics contains four strains of lactic acid bacteria and bifidobacteria that are reflective of the gut of newborn babies and infants. The effect of Lab4b on atherosclerosis, an inflammatory disorder of the vasculature, has not yet been determined and was investigated on key processes associated with this disease in human monocytes/macrophages and vascular smooth muscle cells in vitro. The Lab4b conditioned medium (CM) attenuated chemokine-driven monocytic migration, monocyte/macrophage proliferation, uptake of modified LDL and macropinocytosis in macrophages together with the proliferation and platelet-derived growth factor-induced migration of vascular smooth muscle cells. The Lab4b CM also induced phagocytosis in macrophages and cholesterol efflux from macrophage-derived foam cells. The effect of Lab4b CM on macrophage foam cell formation was associated with a decrease in the expression of several key genes implicated in the uptake of modified LDL and induced expression of those involved in cholesterol efflux. These studies reveal, for the first time, several anti-atherogenic actions of Lab4b and strongly implicate further studies in mouse models of the disease in vivo and in clinical trials