Phytosterol-mediated inhibition of intestinal cholesterol absorption in mice is independent of liver X receptor

The Bioavailability and Biological Activities of Phytosterols as Modulators of Cholesterol Metabolism

Phytosterols are natural sterols widely found in plants that have a variety of physiological functions, and their role in reducing cholesterol absorption has garnered much attention. Although the bioavailability of phytosterols is only 0.5–2%, they can still promote cholesterol balance in the body. A mechanism of phytosterols for lowering cholesterol has now been proposed. They not only reduce the uptake of cholesterol in the intestinal lumen and affect its transport, but also regulate the metabolism of cholesterol in the liver. In addition, phytosterols can significantly reduce the plasma concentration of total cholesterol, triglycerides, and low-density lipoprotein cholesterol (LDL-C), with a dose-response relationship. Ingestion of 3 g of phytosterols per day can reach the platform period, and this dose can reduce LDL-C by about 10.7%. On the other hand, phytosterols can also activate the liver X receptor α-CPY7A1 mediated bile acids excretion pathway and accelerate the transformation and metabolism of cholesterol. This article reviews the research progress of phytosterols as a molecular regulator of cholesterol and the mechanism of action for this pharmacological effect.

Phytosterols as bioactive food components against nonalcoholic fatty liver disease

Phytosterols are bioactive food components widely present in cell membranes of plants, especially in nuts and oilseeds. In recent years, many studies have shown that phytosterols possess therapeutic potentials for nonalcoholic fatty liver disease (NAFLD). This review summarizes the effects of phytosterols from in vitro and in vivo studies to lower the levels of total cholesterol (TC) and triglycerides (TG), and the evidence supporting the potential of phytosterols against NAFLD. The potential mechanisms by which phytosterols improve NAFLD may include (i) competition with cholesterol; (ii) regulation of key factors involved in cholesterol and TG metabolism; and (iii) inhibition of liver inflammation and (iv) regulation of liver fatty acid composition. In summary, phytosterols are potential natural ingredients with good safety profile against NAFLD, which deserve more future studies.

Phytosterols extraction from hickory (Carya cathayensis Sarg.) husk with a green direct citric acid hydrolysis extraction method

This study investigated the direct citric acid hydrolysis extraction method to optimize phytosterols extraction from hickory husk. Single factor experiments followed by a three-level three-factor Box-Behnken experiments were performed. The optimal extraction parameters were determined as: pH of 2.0, liquid-to-solid ratio of 17.12: 1 mL/g, and temperature of 55.81 °C. Practical experiments were carried out in triplicate, and subsequently yielded phytosterols of 912.452 ± 17.452 μg/g DW, in good consistence with the predicted extraction yield of 902.874 μg/g DW. The conductivity of the extract was also found to play effective role under direct citric acid hydrolysis and recorded 36.30 ± 1.08 μs/cm at optimum extraction condition. β-Sitosterol stigmasterol, campsterol, ergosterol and lupeol were detected as main PSs and triterpenoids in hickory husk using UPLC-Triple-TOF/MS. Finally, the comparison between direct hydrolysis extraction and traditional solvent extraction showed that this new method was more effective and eco-friendlier to extract both free and conjugated phytosterols.

Cardiovascular Disease Prevention: The Earlier the Better? A Review of Plant Sterol Metabolism and Implications of Childhood Supplementation

Atherosclerosis is the underlying cause of major cardiovascular events. The development of atherosclerotic plaques begins early in life, indicating that dietary interventions in childhood might be more effective at preventing cardiovascular disease (CVD) than treating established CVD in adulthood. Although plant sterols are considered safe and consistently effective in lowering plasma cholesterol, the health effects of early-life supplementation are unclear. Studies suggest there is an age-dependent effect on plant sterol metabolism: at a younger age, plant sterol absorption might be increased, while esterification and elimination might be decreased. Worryingly, the introduction of low-cholesterol diets in childhood may unintentionally favor a higher intake of plant sterols. Although CVD prevention should start as early as possible, more studies are needed to better elucidate the long-term effects of plant sterol accumulation and its implication on child development.

Plasma Cholesterol-Lowering Activity of Soybean Germ Phytosterols

Soybean germ phytosterols (SGP) largely exist in soybean germ oil. Our previous study demonstrated that soybean germ oil was effective in reducing plasma cholesterol. However, it remains unknown if its phytosterols are the active ingredients responsible for the plasma cholesterol-lowering activity. The present study aimed to test the effect of SGP on plasma cholesterol and to investigate its associated underlying mechanisms using hamsters as animal model. Male hamsters (n = 40) were randomly divided into five groups (n = 8/group) and fed one of the five diets: a non-cholesterol diet (NCD), a high cholesterol diet (HCD), a HCD diet containing 0.5% cholestyramine (PC), and two HCD diets containing 0.1% (LP) and 0.2% (HP) SGP, respectively, for six weeks. Results showed that SPG reduced plasma cholesterol level in a dose-dependent manner, whereas it dose-dependently increased the excretion of both fecal neutral and acidic sterols. SGP was also effective in displacing cholesterol from micelles. It was concluded that SGP possessed hypocholesterolemic activity, likely by inhibiting cholesterol absorption in the intestine and promoting fecal sterol excretion.

Peanut (Arachis hypogaea L.): A Prospective Legume Crop to Offer Multiple Health Benefits Under Changing Climate

Peanut is a multipurpose oil-seed legume, which offer benefits in many ways. Apart from the peanut plant's beneficial effects on soil quality, peanut seeds are nutritious and medicinally and economically important. In this review, insights into peanut origin and its domestication are provided. Peanut is rich in bioactive components, including phenolics, flavonoids, polyphenols, and resveratrol. In addition, the involvement of peanut in biological nitrogen fixation is highly significant. Recent reports regarding peanut responses and N₂ fixation ability in response to abiotic stresses, including drought, salinity, heat stress, and iron deficiency on calcareous soils, have been incorporated. As a biotechnological note, recent advances in the development of transgenic peanut plants are also highlighted. In this context, regulation of transcriptional factors and gene transfer for the development of stress-tolerant peanut genotypes are of prime importance. Above all, this review signifies the importance of peanut cultivation and human consumption in view of the scenario of changing world climate in order to maintain food security.

Add-on therapy with traditional Chinese medicine: An efficacious approach for lipid metabolism disorders

Add-on therapy with traditional Chinese medicine (TCM) has been extensively researched in the intractable diseases, such as asthma, cancer, and Alzheimer's disease. As an entirely new concept, add-on therapy of TCM has been also used to prevent and treat hyperlipidemia via lowering cholesterol level. However, the efficacy of add-on therapy with TCM for mediating lipid metabolism disorders remains controversial. In this review, we summarize and provide strong evidence that add-on therapy of TCM as a novel approach is efficacious and safe for hyperlipidemia associated diseases based on the mediation of lipid metabolism disorders.