Effect of structure and form on the ability of plant sterols to inhibit cholesterol absorption in hamsters

Phytosterols in mountain cultivated ginseng, as master healthy ageing dietary supplement, activates steroid signaling in ageing Drosophila melanogaster

Mountain cultivated ginseng (MCG) is planted in mountain forests to simulate traditional wild ginseng; therefore, it has a greater pharmacological effect than cultivated ginseng (CG) in the garden; however, insufficient evidence confirms this theory. In light of the health-promoting and life-extending properties of ginseng, we analyzed the efficacy of MCG and CG. Initial observations revealed that the phytosterols content of MCG was higher than that of CG, with a positive correlation to the duration of growth. The distinction between phytosterols in MCG and in CG is predominately determined by the stigmasterol content using High-Performance Liquid Chromatography (HPLC). The lifespan of Drosophila melanogaster (fruit flies) that aged naturally was prolonged by phytosterols in MCG and CG and stigmasterols. Further, they prolonged healthy ageing as measured by progeny numbers, length of sleep, climbing distance, and survival following oxidative damage. The findings of behavioral observations revealed that phytosterols in MCG were more efficacious than in CG in promoting health maintenance and life extension; moreover, stigmasterol indicated that these effects were dose-dependent. Stigmasterols, phytosterols in MCG and CG have restored age-associated decreases in steroid hormone levels. Notably, molecular docking was predicted to promote stigmasterol's binding to the steroid hormone receptor ECR due to its similarity to steroid hormones. In addition, stigmasterols triggered the steroid hormone signaling pathway by increasing the activity of key genes Eip75B and Br in 20E signaling and Jhamt, HmGR, Met, and Kr-h1 in JH signaling. Phytosterols, as a natural product, regulated health and longevity as a dietary supplement similar to that of steroids, which supported the social requirements of healthy ageing.

Fermented camel milk enriched with plant sterols improves lipid profile and atherogenic index in rats fed high -fat and -cholesterol diets

The current study was designed to explore the effect of fermented camel milk, plant sterols and their combination on the blood levels of sd-LDL and atherogenicity in rats fed on high-fat-cholesterol diets (HFC). Forty male Wistar rats were distributed into five groups: Normal control (NC), Positive control (PC, HFC), plant sterol (PS, HFC containing 1% (w/w) β-sitosterol:Stigmasterols; 9:1), FM (HFC containing 4% (w/w) lyophilized fermented camel milk), and PSFM (HFC containing 1% (w/w) plant sterols +4% (w/w) lyophilized fermented camel milk). Antioxidant activity showed that β-sitosterol had the highest radical scavenging activity, followed by fermented camel milk and stigmasterol (p < 0.05). Feeding rats on HFC for 8 weeks resulted in a significant (p < 0.05) increase in blood lipids of PC group compared with NC group. Administration of PS, FM, and PSFM resulted in a significant reduction in atherogenic index (50, 24.5, and 41.5 %, p < 0.05), and sd-LDL levels (73, 45, and 59%, p < 0.05), respectively. Only the FM group showed a significant reduction in triglycerides levels of rats. Administration of PS, FM and PSFM decreased serum MDA levels significantly by 58.7, 45.4, and 69% (p < 0.05), and increased total antioxidant capacity by 35.9, 84.8, and 38.3% (p < 0.05), respectively. This is the first report to the best of our knowledge that shows fermented camel milk enriched with plant sterol could reduce atherogenesis and cardiovascular diseases activity via inhibition of the status of small dense LDL and oxidative stress.

Plantain based dough meal: nutritional property, antioxidant activity and dyslipidemia ameliorating potential in high-fat induced rats

Background

Dyslipidemia is an aberrant rise in blood lipids due to diet and lifestyle. It has implicated as the major risk factor for developing hypertension among other diseases. This study was designed to evaluate plantain based dough meal nutritional property, antioxidant activity and dyslipidemia ameliorating potential in high-fat induced rats.

Methods

The flour blends, i.e., PSC (Plantain 70%, Soycake 30%), PSR (Plantain 65%, Soycake 30%, Rice-bran 5%), PSO (Plantain 65%, Soycake 30%, Oat-bran 5%), PSRO (Plantain 60%, Soycake 30%, Rice-bran 5%, Oat-bran 5%) and controls (100% Plantain flour & Cerolina) were evaluated for chemical, antioxidants and antihyperlipidemia.

Results

Protein, fiber and energy composition varied from 2.2–4.97 g/100 g, 16.44–19.59 g/100 g and 369.7–385.5 kcal/100 g, respectively. Essential amino acid index and predicted-biological values of the foods ranged from 68.31–76.31% and 62.19–71.48%, respectively. Phenolic profiles (mg/g) were gallic acid (25.33–31.26), caffeic acid (2.75–4.61), ferulic acid (5.16–12.73), luteolin (16.31–23.60), kaempferol (21.51–30.64), quercetin (24.28–37.13), chlorogenic acid (42.25–59.78), myricetin (28.41–38.41), 3,5-dicaffeoylquinic acid (27.17–41.59) and 4, 5-dicaffeoylquinic acid (39.96–51.28). The antioxidant activity of PSRO on ABTS, DPPH, FRAP, Fe2+ chelation and OH free radicals was higher than other foods. Atherogenic index, coronary risk index and log (TG/HDL-conc.) of rats fed on experimental foods were lower than recommended values.

Conclusion

The study established that PSRO had higher antioxidant and anti-hyperlipidemia properties; hence, it may be suitable as a functional food.

Methodological Aspects of Phytosterol Measurements in Biological Samples

Phytosterol measurement has gained a lot of interest during the last two decades after foods and supplements with added 4-desmethyl phytosterols were recognized and used as effective and safe non-pharmacologic hypocholesterolemic agents, and also after the mechanisms of intestinal absorption and hepatic excretion of sterols were unraveled. In addition, the wide use of serum phytosterols as biomarkers of cholesterol absorption has increased the interest in their measurement. In this review, the basic methods are discussed without going into details of the practical operations. The analysis includes first lipid extraction and saponification from various biologic matrices such as serum/plasma, feces, or tissues, after which the individual sterols are separated by adsorption chromatography (gas-liquid or liquid or high performance liquid chromatography) based on the polarity of the various sterols. We also deal with some specific aspects of phytosterol measurements in biological samples such as the need of harmonization of their analysis in biological samples, the discrepancies in the results of sitosterol and campesterol concentrations between different studies, and what is known about their biological day-to-day fluctuation. Phytosterols have a remarkable role in human health, so that their complicated and time consuming measurements call attention to routine ways of standardization between the sterol research laboratories.

Oral shea nut oil triterpene concentrate supplement ameliorates pain and histological assessment of articular cartilage deterioration in an ACLT injured rat knee osteoarthritis model

Osteoarthritis (OA) is a multifactorial joint disease and a common disabling condition in the elderly population. The associated pain and pathohistological changes in cartilage are common features of OA in both humans and animal models. Shea nut oil extract (SheaFlex75) contains a high triterpenoid concentration and has demonstrated anti-inflammatory and antiarthritic effects in both human and animal studies. In this study, we aim to investigate the potential of SheaFlex75 to prevent articular cartilage deterioration in a rat model of chronic OA progression. By employing anterior cruciate ligament transection (ACLT) with medial meniscectomy (MMx)-induced OA, we found attenuation of both early and chronic onset OA pain and cartilage degeneration in ACLT+MMx rats receiving SheaFlex75 dietary supplementation. Under long-term oral administration, the rats with induced OA presented sustained protection of both pain and OA cartilage integrity compared to the OA-control rats. Moreover, rats subjected to long-term SheaFlex75 ingestion showed normal biochemical profiles (AST, BUN and total cholesterol) and presented relatively lower triglycerides (TGs) and body weights than the OA-control rats, which suggested the safety of prolonged use of this oil extract. Based on the present evidence, preventive management is advised to delay/prevent onset and progression in OA patients. Therefore, we suggest that SheaFlex75 may be an effective management strategy for symptom relief and cartilage protection in patients with both acute and chronic OA.

Phytosterol Profiles of Common Foods and Estimated Natural Intake of Different Structures and Forms in China

Phytosterols are well-known for their cholesterol-lowering effects, and the structures and forms of phytosterols affect their bioactivity. We aimed to illustrate the phytosterol profiles in common foods and estimate their natural intake in five geographical regions and among different age groups in China. In total, 12 phytosterols in free and esterified forms of 119 foods from five regions across China were examined using gas chromatography-mass spectrometry. Then, the dietary intake of phytosterols was calculated combined with the dietary foods intake data of Chinese people. The total phytosterol content was highest in vegetable oils (150.4-1230.9 mg/100 g), followed by legumes (129.6-275.6 mg/100 g), nuts (18.9-255.2 mg/100 g), and cereals (11.9-93.8 mg/100 g). Vegetables and fruits contained lower contents of total phytosterols. Phytosterols were mainly esterified in most common foods except in nuts. The predominant phytosterols were β-sitosterol, campesterol, and stigmasterol, all of which belonged to plant sterols and 4-desmethylsterols. Total phytosterol intake varied across different regions, ranging between 257.7 and 473.7 mg/standard-person (sp)/day, with the highest intake in Beijing, followed by Hangzhou, Wuhan, Chongqing, and Guangzhou. However, phytosterol proportion was similar across regions, with β-sitosterol accounting for 46.5-50.3% of the natural intake. Phytosterol intake was mainly constituted by plant sterols and 4-desmethylsterols in esterified form (61.9-74.6%). At the age of 2-70 years, phytosterol intake ranged from 154.3 mg/day to 348.0 mg/day in the national scale.

Rice brans, rice bran oils, and rice hulls: composition, food and industrial uses, and bioactivities in humans, animals, and cells

Rice plants produce bioactive rice brans and hulls that have been reported to have numerous health-promoting effects in cells, animals, and humans. The main objective of this review is to consolidate and integrate the widely scattered information on the composition and the antioxidative, anti-inflammatory, and immunostimulating effects of rice brans from different rice cultivars, rice bran oils derived from rice brans, rice hulls, liquid rice hull smoke derived from rice hulls, and some of their bioactive compounds. As part of this effort, this paper also presents brief summaries on the preparation of health-promoting foods including bread, corn flakes, frankfurters, ice cream, noodles, pasta, tortillas, and zero-trans-fat shortening as well as industrial products such bioethanol and biodiesel fuels. Also covered are antibiotic, antiallergic, anticarcinogenic, antidiabetic, cardiovascular, allelochemical, and other beneficial effects and the mechanisms of the bioactivities. The results show that food-compatible and safe formulations with desirable nutritional and biological properties can be used to develop new multifunctional foods as well as bioethanol and biodiesel fuel. The overlapping aspects are expected to contribute to a better understanding of the potential impact of the described health-promoting potential of the rice-derived brans, oils, and hulls in food and medicine. Such an understanding will enhance nutrition and health and benefit the agricultural and industrial economies.

Cholesterol-lowering effects of plant steryl and stanyl laurate by oral administration in mice

The present study was conducted to investigate the efficacy of synthesized plant steryl and stanyl laurate in lowering the cholesterol level and to further examine the cholesterol-lowering potential of the free plant sterols and stanols dissolved in liquid emulsion on serum and liver lipids in mice by oral administration. Experimental results showed that both plant steryl and stanyl laurate could significantly decrease the serum levels of TC, LDL-C, LDL-C/HDL-C, and liver cholesterol contents and markedly increase fecal cholesterol concentrations but have no effect on serum TAG level, indicating that the produced plant steryl and stanyl laurate retained the cholesterol-lowering potential of natural plant sterols and stanols. However, no statistical difference in cholesterol-lowering efficacy was observed between plant steryl laurate and plant stanyl laurate, and free plant sterols and stanols dissolved in liquid emulsion could also significantly decrease serum cholesterol levels and markedly increase fecal cholesterol excretion. These results suggested that the esterified plant sterols/stanols had comparable effects to the free plant sterols/stanols in lowering serum TC levels but that they did gain a solubility advantage from the free plant sterols/stanols. Therefore, plant steryl/stanyl laurate could be considered as a potential nutraceutical or functional ingredient to reduce or prevent atherosclerosis and its related complications.

Therapies targeting exogenous cholesterol uptake: new insights and controversies

Exogenous cholesterol uptake involves a complex process in the intestines for the absorption of cholesterol and bile acids. This process is regulated by intestinal nuclear transcription factors such as LXR that affect sterol transporters NPC1L1, ABCG5/G8, and ABCG1, and enzymes such as ACAT-2. Plant sterol/stanols, ezetimibe, and bile acid sequestrants have a variety of effects on these various transporters, and new insights into their mechanism(s) of action have provided a plethora of exciting targets for metabolic diseases, dyslipidemia, and atherosclerosis.

Use of hamster as a model to study diet-induced atherosclerosis

Golden-Syrian hamsters have been used as an animal model to assess diet-induced atherosclerosis since the early 1980s. Advantages appeared to include a low rate of endogenous cholesterol synthesis, receptor-mediated uptake of LDL cholesterol, cholesteryl ester transfer protein activity, hepatic apoB-100 and intestinal apoB-48 secretion, and uptake of the majority of LDL cholesterol via the LDL receptor pathway. Early work suggested hamsters fed high cholesterol and saturated fat diets responded similarly to humans in terms of lipoprotein metabolism and aortic lesion morphology. Recent work has not consistently replicated these findings. Reviewed was the literature related to controlled hamster feeding studies that assessed the effect of strain, background diet (non-purified, semi-purified) and dietary perturbation (cholesterol and/or fat) on plasma lipoprotein profiles and atherosclerotic lesion formation. F1B hamsters fed a non-purified cholesterol/fat-supplemented diet had more atherogenic lipoprotein profiles (nHDL-C > HDL-C) than other hamster strains or hamsters fed cholesterol/fat-supplemented semi-purified diets. However, fat type; saturated (SFA), monounsaturated or n-6 polyunsaturated (PUFA) had less of an effect on plasma lipoprotein concentrations. Cholesterol- and fish oil-supplemented semi-purified diets yielded highly variable results when compared to SFA or n-6 PUFA, which were antithetical to responses observed in humans. Dietary cholesterol and fat resulted in inconsistent effects on aortic lipid accumulation. No hamster strain was reported to consistently develop lesions regardless of background diet, dietary cholesterol or dietary fat type amount. In conclusion, at this time the Golden-Syrian hamster does not appear to be a useful model to determine the mechanism(s) of diet-induced development of atherosclerotic lesions.

Influence of growth temperature on the amounts of tocopherols, tocotrienols, and gamma-oryzanol in brown rice

Brown rice is a valuable source of lipid-soluble antioxidants including ferulated phytosterols (i.e., gamma-oryzanol), tocopherols, and tocotrienols. To evaluate the impact of temperature on the accumulation of these compounds, seeds from six different rice lines grown to maturity in replicate greenhouses in Gainesville, FL, were analyzed. The lines represented Oryza sativa indica, O. sativa japonica, and Oryza glaberrima of different origins. Temperatures were maintained near ambient at one end of each greenhouse and at approximately 4.5 degrees C above ambient at the other end. gamma-Oryzanols, tocopherols, and tocotrienols were extracted from whole seed (i.e., brown rice) and analyzed by HPLC. Tocotrienols and tocopherols varied widely between lines but changed only slightly with respect to temperature. In general, the proportions of alpha-tocotrienol and/or alpha-tocopherol increased at elevated temperature, whereas gamma-tocopherol and gamma-tocotrienol decreased. Six gamma-oryzanol peaks, identified on the basis of absorbance maxima at 330 nm and HPLC-mass spectrometry, were quantified. The most abundant component was 24-methylenecycloartanyl ferulate, present at 40-62% of total. Its levels increased 35-57% at elevated temperature in five of six lines, accounting for most of the change in total gamma-oryzanol. The results suggest that the physiological action of individual ferulated phytosterols should be investigated because their relative proportions in gamma-oryzanol can change.

Dose-response effects of different plant sterol sources in fat spreads on serum lipids and C-reactive protein and on the kinetic behavior of serum plant sterols

OBJECTIVE

To test the dose-response effect on low-density lipoprotein cholesterol (LDL-c) of plant sterols (PS) from different sources in a low-fat spread.

METHODS

Dose responses of soybean oil (BO), tall oil (TO) and a mix of tall oil and rapeseed oil (TO/RP) as fatty acid esters were tested in a parallel design in free-living subjects recruited from the general community who had elevated cholesterol concentrations. Subjects received either control for 6 weeks or 1.6 g PS per day for 3 weeks, then 3.0 g/day for 3 weeks.

RESULTS

LDL-c was lowered significantly by consumption of 1.6 g/day of PS (-10.4%, range -7.3 to -11.4%). Increasing the dose to 3.0 g/day modestly reduced LDL-c concentrations further to -14.7%. TO, containing 78% sitosterol, produced an increase in serum sitosterol of 6.5 nmol/ml, while BO, containing only 27% campesterol, produced an increase in serum campesterol of 9.5 nmol/ml in 6 weeks. After PS withdrawal, serum sterols declined by 50% within 2 weeks.

CONCLUSION

Different PS sources were equally effective in lowering serum LDL-c concentrations. The decrease in absolute concentrations of LDL-c was dependent on the baseline concentrations.

Plant stanol ascorbate esters reduce body weight gain through decreased energy absorption in hamsters

OBJECTIVE

The objective of this study was to determine the effects of disodium ascorbyl phytostanyl phosphate (DAPP), a novel hydrophilic phytostanol analogue, on energy homeostasis, including body weight and intestinal energy absorption, and plasma triglyceride concentrations, in hamsters.

METHODS

Male Golden Syrian hamsters (n = 50) were fed for 5 weeks with experimental diets varying in cholesterol and phytostanol content. Diets included (i) non-cholesterol (semipurified diet without added cholesterol), (ii) cholesterol-control (semipurified diet with 0.25% cholesterol), (iii) stanol (cholesterol-control with 1% free phytostanols), (iv) DAPP 0.7% (cholesterol-control with 0.71% DAPP) or (v) DAPP 1.4% (cholesterol-control with 1.43% DAPP). Fecal samples were collected continuously for 3 days on week 3, and fecal energy output was measured by bomb calorimetry.

RESULTS

Hamsters fed 1.4% DAPP gained less (P<0.05) weight than hamsters fed non-cholesterol and stanol diets. Diets had no effect on total food consumption or gross energy intake after 5 weeks, but lower (P<0.05) weekly food consumptions in hamsters fed 1.4% DAPP were observed at weeks 1 and 2 of the experiment in comparison to animals fed the non-cholesterol diet. In comparison to non-cholesterol and cholesterol-control diets, DAPP 1.4% increased (P<0.01) fecal energy output by 47 and 46%, respectively. In hamsters supplemented with 1.4% DAPP, plasma triglyceride concentrations were 45% lower (P<0.05) than in cholesterol-control fed hamsters. Furthermore, plasma triglyceride levels in the DAPP 1.4% group was 49% lower (P<0.01) than in the stanol group, despite the fact that both diets contained equivalent amounts of phytostanols. The lower concentration of DAPP (0.7%) also reduced plasma triglycerides (P<0.05) compared with the stanol diet.

CONCLUSION

Stanol-ascorbate decreases body weight gain in hamsters, likely due to lower energy absorption at the intestinal level. In addition to its previously observed powerful cholesterol-lowering effect, DAPP has a hypotriglyceridemic function in hamsters.

Fish oil fatty acid esters of phytosterols alter plasma lipids but not red blood cell fragility in hamsters

In an attempt to combine the hypocholesterolemic properties of plant sterols with the hypotriglyceridemic action of fish oil FA, plant sterols have recently been esterified to fish oil n-3 PUFA. The objective of this study was to determine the effects of plant sterols esterified to n-3 PUFA on plasma lipid levels and erythrocyte fragility. For 5 wk, male Golden Syrian hamsters were fed diets varying in cholesterol and plant sterol content: (i) Non-cholesterol (semipurified diet with no added cholesterol or plant sterols) (ii), Cholesterol (0.25% cholesterol) (iii), Sterols (0.25% cholesterol plus 1% nonesterified plant sterols), or (iv) Fish oil esters of plant sterols (0.25% cholesterol plus 1.76% EPA and DHA sterol esters, providing 1% plant sterols). The addition of fish oil esters of plant sterols to the cholesterol diet decreased (P = 0.001) plasma total cholesterol levels by 20%, but nonesterified plant sterols did not have such a beneficial impact. In addition, non-HDL cholesterol concentrations were 29% lower in hamsters fed fish oil esters of plant sterols than in hamsters fed nonesterified plant sterols (P < 0.0001). Despite higher (P < 0.0001) plant sterol levels in whole erythrocytes of hamsters fed nonesterified plant sterols and fish oil esters of plant sterols compared with hamsters fed no plant sterols, no difference was observed in erythrocyte fragility. The present results show that EPA and DHA esters of plant sterols have a hypocholesterolemic effect in hamsters, and that these new esters of plant sterols exert no detrimental effect on erythrocyte fragility.

Definition of Soybean Genomic Regions That Control Seed Phytoestrogen Amounts

Soybean seeds contain large amounts of isoflavones or phytoestrogens such as genistein, daidzein, and glycitein that display biological effects when ingested by humans and animals. In seeds, the total amount, and amount of each type, of isoflavone varies by 5 fold between cultivars and locations. Isoflavone content and quality are one key to the biological effects of soy foods, dietary supplements, and nutraceuticals. Previously we had identified 6 loci (QTL) controlling isoflavone content using 150 DNA markers. This study aimed to identify and delimit loci underlying heritable variation in isoflavone content with additional DNA markers. We used a recombinant inbred line (RIL) population ( $n=100$ ) derived from the cross of “Essex” by “Forrest,” two cultivars that contrast for isoflavone content. Seed isoflavone content of each RIL was determined by HPLC and compared against 240 polymorphic microsatellite markers by one-way analysis of variance. Two QTL that underlie seed isoflavone content were newly discovered. The additional markers confirmed and refined the positions of the six QTL already reported. The first new region anchored by the marker BARC-Satt063 was significantly associated with genistein ( $P=0.009$, $Rcirc;2=29.5\%$ ) and daidzein ( $P=0.007$, $Rcirc;2=17.0\%$ ). The region is located on linkage group B2 and derived the beneficial allele from Essex. The second new region defined by the marker BARC-Satt129 was significantly associated with total glycitein ( $P=0.0005$, $Rcirc;2=32.0\%$ ). The region is located on linkage group D1a+Q and also derived the beneficial allele from Essex. Jointly the eight loci can explain the heritable variation in isoflavone content. The loci may be used to stabilize seed isoflavone content by selection and to isolate the underlying genes.