Combined effect of plant sterols and dietary fiber for the treatment of hypercholesterolemia

Dietary fiber influence on overall health, with an emphasis on CVD, diabetes, obesity, colon cancer, and inflammation

Dietary fiber, found in plant-based foods, plays an essential role in human health. It is divided into two types-soluble and insoluble-both offering significant health benefits. Research has shown that increasing fiber intake can reduce the risk of various chronic diseases, such as cardiovascular diseases (CVD), type II diabetes, obesity, colon cancer, and inflammation. These health conditions are major global challenges, making fiber consumption a key focus for disease prevention. This study reviews a range of clinical trials, cohort studies, and meta-analyses to explore how dietary fiber affects these health risks. By synthesizing data from multiple sources, we found a clear association between higher fiber intake and a lower incidence of these diseases. However, studying the effects of fiber on health presents several challenges. Variations in fiber types and bioavailability make it difficult to generalize results. Additionally, dietary intake is often self-reported, leading to potential inaccuracies in data. Many studies also lack consistency in methodology, and short study durations limit the ability to assess long-term health outcomes. These factors make it harder to draw definitive conclusions about the full range of fiber's health benefits. Despite these challenges, increasing fiber-rich foods like fruits, vegetables, whole grains, and legumes remains a highly recommended strategy for improving health and reducing the risk of chronic disease.

Protective effect of Chaetomorpha gracilis aqueous extract against erythrocytes oxidative damage induced by high fat diet in treated mice

High fat diet (HFD) exposure is associated with various pathological dysfunctions, including haematological disorders and oxidative stress. The in vitro analysis of AECG revealed the presence of important levels of polyphenols and flavonoids, and denoted antioxidant capacities confirmed by nitric oxide radical (NO^•), reducing the power and HPLC chemical components' determinations. The animals exposed to HFD revealed a severe damage in the blood cells structure and haematological parameters accompanied with a significant decrease in serum Mg²⁺ and Ca²⁺ ATPase activities. Furthermore, malondialdehyde (MDA) and the advanced oxidation of protein products (AOPP) levels were significantly increased, while vitamin C level, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities were markedly reduced in the erythrocytes and platelets of HFD-treated mice. However, the co-administration of AECG with HFD-treated animals restored the parameters cited above to near-normal values. Therefore, our investigation revealed that Chaetomorpha gracilis extract was a useful element preventing HFD-induced blood cells damage.

Hepatoprotective and in vitro antioxidant effects of native depolymerised-exopolysaccharides derived from Termitomyces albuminosus

In this study, native depolymerised-exopolysaccharides (DEPS) were successfully derived from the exopolysaccharides (EPS) of Termitomyces albuminosus, and its hepatoprotective effects against a high-fat emulsion and in vitro antioxidant activities were investigated. Based on the results of in vitro assays, DEPS showed superior antioxidant activities compared with EPS dose-dependently. According to the in vivo assays both EPS and DEPS significantly decreased the lipid levels, improved the enzymatic activities, and reduced lipid peroxidation in both serum and hepatic homogenates. Furthermore, EPS and DEPS attenuated the high-fat emulsion-induced histopathological injury to the liver. Both EPS and DEPS might be used as natural drugs to treat and protect against hyperlipidaemia and liver injury induced by a high-fat emulsion. In addition, based on the results of GC and HPLC analyses, rhamnose and low molecular weight compounds may play an important role in contributing to the antioxidant activities of EPS and DEPS.

Joint position statement on "Nutraceuticals for the treatment of hypercholesterolemia" of the Italian Society of Diabetology (SID) and of the Italian Society for the Study of Arteriosclerosis (SISA)

AIM

Evidence showed that LDL-cholesterol lowering is associated with a significant cardiovascular risk reduction. The initial therapeutic approach to hypercholesterolemia includes dietary modifications but the compliance to recommendations is often inadequate. Some dietary components with potential cholesterol-lowering activity are present in small amounts in food. Therefore, in recent years the use of "nutraceuticals" (i.e., nutrients and/or bioactive compounds with potential beneficial effects on human health) has become widespread. Such substances may be added to foods and beverages, or taken as dietary supplements (liquid preparations, tablets, capsules). In the present manuscript, the cholesterol-lowering activity of some nutraceuticals (i.e. fiber, phytosterols, soy, policosanol, red yeast rice and berberine) will be discussed along with: 1) the level of evidence on the cholesterol-lowering efficacy emerging from clinical trial; 2) the possible side effects associated with their use; 3) the categories of patients who could benefit from their use.

DATA SYNTHESIS

Based on the current literature, the cholesterol-lowering effect of fiber, phytosterols and red yeast rice is consistent and supported by a good level of evidence. Over berberine, there is sufficient evidence showing significant cholesterol-lowering effects, although the results come from studies carried out almost exclusively in Asian populations. Data on the effects of soy are conflicting and, therefore, the strength of recommendation is quite low. The evidence on policosanol is inconclusive.

CONCLUSION

Although health benefits may arise from the use of nutraceuticals with cholesterol-lowering activity, their use might be also associated with possible risks and pitfalls, some of which are common to all nutraceuticals whereas others are related to specific nutraceuticals.

Phytosterols and Dementia

As the aging of the world's population is becoming increasingly serious, dementia-related diseases have become a hot topic in public health research. In recent years, human epidemiological studies have focused on lipid metabolism disorders and dementia. The efficacy of phytosterol intake as a cholesterol-lowering agent has been demonstrated. Phytosterols directly serve as ligands of the nuclear receptors, peroxisome proliferator-activated receptors (PPARs), activating Sirtuin 1 (SIRT-1), which are involved in the regulation of lipid metabolism and the pathogenesis of dementia. Moreover, phytosterols mediate cell and membrane cholesterol efflux or beta amyloid (Aβ) metabolism, which have preventative and therapeutic effects on dementia. Additionally, incorporation of plant sterols in lipid rafts can effectively reduce dietary fat and alter the dietary composition of fiber, fat and cholesterol to regulate appetite and calories. Overall, the objectives of this review are to explore whether phytosterols are a potentially effective target for the prevention of dementia and to discuss a possible molecular mechanism by which phytosterols play a role in the pathogenesis of dementia via the PPARs-SIRT-1 pathway.

Antihyperlipidemic and Antioxidant Activities of Edible Tunisian Ficus carica L. Fruits in High Fat Diet-Induced Hyperlipidemic Rats

The phenolic constituents of the aqueous-ethanolic extract of Tunisian Ficus carica (F. carica) fruit (FE) and its antihyperlipidemic and antioxidant activities in high-fat diet-induced hyperlipidemic rats (HFD) were evaluated. The obtained results demonstrated that the FE improved the lipid profile by decreasing the total cholesterol, triglyceride, low-density lipoprotein cholesterol and increasing high-density lipoprotein cholesterol levels. It also reduced the content of thiobarbituric acid-reactive substances and increased the antioxidant enzymes in liver, heart and kidney in HFD-fed rats. These antihyperlipidemic effects and in vivo antioxidative effects correlated with the in vitro phenolic content scavenging ability. Thus, the major phenolic compounds were identified using reversed-phase ultra-high-performance liquid chromatography (RP-UHPLC) coupled with two detection systems: diode-array detection (DAD) and quadrupole time-of-flight (QTOF) mass spectrometry (MS). Therefore, in the negative ionization mode, 28 phenolic compounds, including hydroxybenzoic acids, hydroxycinnamic acids, flavanoids and hydroxycoumarins were characterized. Dihydroxybenzoic acid di-pentoside, the flavonol quercetin 3-O-rutinoside and the flavone assigned as apigenin 8-C-glucoside were the main representative compounds in 'Tounsi' fruits. This work was complemented by the detection of seven other phenolic compounds in the positive ionization mode, including anthocyanins and furanocoumarins. Overall, these results have shown that the FE has a significant hypocholesterolemic effect and antioxidant activity in HFD-fed rats. This beneficial effect may be partly due to these phenolic constituents, especially vitexin, dihydroxybenzoic acid di-pentoside as well as rutin.

New Horizons for the Study of Dietary Fiber and Health: A Review

Dietary fibre has been consumed for centuries with known health benefits, but defining dietary fibre is a real challenge. From a functional perspective, dietary fibre is described as supporting laxation, attenuating blood glucose responses and assisting with cholesterol lowering. The problem is different types of dietary fibre have different effects, and new effects are increasingly observed, such as the influence on gut microbiota. Thus, a single definition may need to be described in more generic terms. Rather than being bound by a few functional definitions, we may need to embrace the possibilities of new horizons, and derive a working definition of dietary fibre based on a set of conceptual principles, rather than the limited definitions we have to date. To begin this process, a review of individual fibre types and their physiological effects would be helpful. Dietary fibre is a complex group of substances, and there is a growing interest in specific effects linked to fibre type. Different fractions of dietary fibre have different physiological properties, yet there is a paucity of literature covering the effects of all fibres. This paper describes a range of individual fibre types and identifies gaps in the literature which may expose new directions for a working definition of dietary fibre.

Cholesterol esterase inhibitory activity of bioactives from leaves of Mangifera indica L

Background:

In the earlier studies, methanolic extract of Mangifera indica L leaf was exhibited hypocholesterol activity. However, the bioactive compounds responsible for the same are not reported so far.

Objective:

To isolate the bioactive compounds with hypocholesterol activity from the leaf extract using cholesterol esterase inhibition assay which can be used for the standardization of extract.

Materials and Methods:

The leaf methanolic extract of M. indica (Sindoora variety) was partitioned with ethyl acetate and chromatographed on silica gel to yield twelve fractions and the activity was monitored by using cholesterol esterase inhibition assay. Active fractions were re-chromatographed to yield individual compounds.

Results and Discussion:

A major compound mangiferin present in the extract was screened along with other varieties of mango leaves for cholesterol esterase inhibition assay. However, the result indicates that compounds other than mangiferin may be active in the extract. Invitro pancreatic cholesterol esterase inhibition assay was used for bioactivity guided fractionation (BAGF) to yield bioactive compound for standardization of extract. Bioactivity guided fractionation afford the active fraction containing 3b-taraxerol with an IC50 value of 0.86μg/ml.

Conclusion:

This study demonstrates that M. indica methanol extract of leaf have significant hypocholesterol activity which is standardized with 3b-taraxerol, a standardized extract for hypocholesterol activity resulted in development of dietary supplement from leaves of Mangifera indica.

Complementary Cholesterol-Lowering Response of a Phytosterol/α-Lipoic Acid Combination in Obese Zucker Rats

To investigate the cholesterol-lowering effectiveness of a phytosterol/α-lipoic acid (PS/αLA) therapy, thirty-two male Zucker rats were randomly assigned to 1 of 4 diets for 30 days: (i) high fat diet (HF, 40% energy from fat); (ii) HF diet supplemented with 3% phytosterols; (iii) HF diet supplemented with 0.25% αLA; or (iv) HF diet supplemented with PS (3%) and αLA (0.25%, PS/αLA). Compared with the HF diet, combination PS/αLA proved more effective in reducing non-HDL cholesterol (-55%) than either the PS (-24%) or the αLA (-25%) therapies alone. PS supplementation did not affect LDL particle number, however, αLA supplementation reduced LDL particle number when supplemented alone (-47%) or in combination with PS (-54%). Compared with the HF-fed animals, evidence of increased HDL-particle number was evident in all treatment groups to a similar extent (21-22%). PS-mediated interruption of intestinal cholesterol absorption was evident by increased fecal cholesterol loss (+52%) and compensatory increase in HMG-CoA reductase mRNA (1.6 fold of HF), however, αLA supplementation did not affect fecal cholesterol loss. Hepatic mRNA and protein expression patterns suggested that αLA modulated multiple aspects of cholesterol homeostasis including reduced synthesis (HMG-CoA reductase mRNA, 0.7 fold of HF), reduced bile acid synthesis (CYP7a1 expression, 0.17 of HF), and increased cholesterol clearance (reduced PCSK9 mRNA, 0.5 fold of HF; increased LDLr protein, 2 fold of HF). Taken together, this data suggests that PS and αLA work through unique and complementary mechanisms to provide a superior and more comprehensive cholesterol lowering response than either therapy alone.