A highly efficient step-wise biotransformation strategy for direct conversion of phytosterol to boldenone

Collaborative microbial communities are ubiquitous in nature and exhibit appealing functions for enhanced production of natural products, which provides new possibility for biotechnology development. In this study, we bridged Mycobacterium neoaurum with Pichia pastoris to establish a step-wise biotransformation strategy for efficient biosynthesis of boldenone (BD) from phytosterol (PS). Firstly, the producing strains were rationally designed with overexpression of 3-ketosteroid-Δ1-dehydrogenase (KsdD) and 17β-hydroxysteroid dehydrogenase (17βHSD) in M. neoaurum and P. pastoris, respectively. Then, to shorten the total biotransformation process and provide reducing power, semi-batch fermentation strategy and glucose supplementation strategy were introduced at side-chain degradation stage and carbonyl reduction stage, respectively. Under the optimal transformation conditions, the productivity of BD was increased from 10% to 76% and the total biotransformation process was shortened by 41.7%, which is the shortest among the ever reported. Our results demonstrated an excellent biological strategy for production of many other valuable microbial products from bioresources.

VKM Ac-1817D

Background

Aerobic side chain degradation of phytosterols by actinobacteria is the basis for the industrial production of androstane steroids which are the starting materials for the synthesis of steroid hormones. A native strain of Mycobacterium sp. VKM Ac-1817D effectively produces 9α-hydroxyandrost-4-ene-3,17-dione (9-OH-AD) from phytosterol, but also is capable of slow steroid core degradation. However, the set of the genes with products that are involved in phytosterol oxidation, their organisation and regulation remain poorly understood.

Results

High-throughput sequencing of the global transcriptomes of the Mycobacterium sp. VKM Ac-1817D cultures grown with or without phytosterol was carried out. In the presence of phytosterol, the expression of 260 genes including those related to steroid catabolism pathways significantly increased. Two of the five genes encoding the oxygenase unit of 3-ketosteroid-9α-hydroxylase (kshA) were highly up-regulated in response to phytosterol (55- and 25-fold, respectively) as well as one of the two genes encoding its reductase subunit (kshB) (40-fold). Only one of the five putative genes encoding 3-ketosteroid-∆¹-dehydrogenase (KstD_1) was up-regulated in the presence of phytosterol (61-fold), but several substitutions in the conservative positions of its product were revealed.

Among the genes over-expressed in the presence of phytosterol, several dozen genes did not possess binding sites for the known regulatory factors of steroid catabolism. In the promoter regions of these genes, a regularly occurring palindromic motif was revealed. The orthologue of TetR-family transcription regulator gene Rv0767c of M. tuberculosis was identified in Mycobacterium sp. VKM Ac-1817D as G155_05115.

Conclusions

High expression levels of the genes related to the sterol side chain degradation and steroid 9α-hydroxylation in combination with possible defects in KstD_1 may contribute to effective 9α-hydroxyandrost-4-ene-3,17-dione accumulation from phytosterol provided by this biotechnologically relevant strain. The TetR-family transcription regulator gene G155_05115 presumably associated with the regulation of steroid catabolism. The results are of significance for the improvement of biocatalytic features of the microbial strains for the steroid industry.

Electronic supplementary material

The online version of this article (10.1186/s12896-019-0533-7) contains supplementary material, which is available to authorized users.

Modification of phytosterol composition influences cotton fiber cell elongation and secondary cell wall deposition

BACKGROUND

Cotton fiber is a single cell that arises from the epidermis of ovule. It is not only a main economic product of cotton, but an ideal material for studying on the growth and development of plant cell. Our previous study indicated that phytosterol content and the ratio of campesterol to sitosterol fluctuated regularly in cotton fiber development. However, what effects of modified phytosterol content and composition on the growth and development of cotton fiber cell is unknown. In this study, we overexpressed the GhSMT2-1, a cotton homologue of sterol C-24 methyltransferase 2 gene in transgenic upland cotton plants to modify phytosterol content and composition in fiber cells and investigated the changes on fiber elongation and secondary cell wall deposition.

RESULTS

GhSMT2-1 overexpression led to changes of phytosterol content and the ratio of campesterol to sitosterol in fiber cell. At the rapid elongation stage of fiber cell, total phytosterol and sitosterol contents were increased while campesterol content was decreased in transgenic fibers when compared to control fibers. Accordingly, the ratio of campesterol to sitosterol declined strikingly. Simultaneously, the transgenic fibers were shorter and thicker than control fibers. Exogenous application of sitosterol or campesterol separately inhibited control fiber cell elongation in cotton ovule culture system in vitro. In addition, campesterol treatment partially rescued transgenic fiber elongation.

CONCLUSION

These results elucidated that modification of phytosterol content and composition influenced fiber cell elongation and secondary cell wall formation. High sitosterol or low ratio of campesterol to sitosterol suppresses fiber elongation and/or promote secondary cell wall deposition. The roles of sitosterol and campesterol were discussed in fiber cell development. There might be a specific ratio of campesterol to sitosterol in different developmental stage of cotton fibers, in which GhSMT2-1 play an important role. Our study, at a certain degree, provides novel insights into the regulatory mechanisms of fiber cell development.

Phytosterol Supplementation Could Improve Atherogenic and Anti-Atherogenic Apolipoproteins: A Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials

Phytosterol and phytostanol (PS) supplementation is reported to improve atherogenic and anti-atherogenic apolipoproteins (Apo). The purpose of the present study is to critically investigate the effectiveness of PS supplementation on Apo in adults.A comprehensive search was conducted of all randomized controlled trials (RCTs) conducted up to September 2018 in the following databases: PubMed, Web of Science, Cochrane Library, and Scopus. Mean difference with 95% confidence intervals (CIs) were pooled using a random-effects model (DerSimonian-Laird method).Fifty-one arms from 37 RCTs were included in the present meta-analysis. Findings showed that PS supplementation and fortification increased Apo-AI (weighted mean difference [WMD]: 0.014 mg/dl, 95% CI: 0.001, 0.028, p = 0.042) and Apo-CII (WMD: 0.303 mg/dl, 95% CI: 0.084, 0.523, p = 0.007) and lowered Apo-B (WMD: -0.063 mg/dl, 95% CI: -0.075, -0.051, p < 0.001), Apo-B/Apo-A-I ratio (WMD: -0.044 mg/dl, 95% CI: -0.062, -0.025, p < 0.001), and Apo-E (WMD: -0.255 mg/dl, 95% CI: -0.474, -0.036, p = 0.023). However, PS supplementation did not have significant effects on Apo-AII and Apo-CIII. PS supplementation or fortification significantly changes Apo-E (r = -0.137, p nonlinearity = 0.006) and Apo-CIII (r = 1.26, p nonlinearity = 0.028) based on PS dosage (mg/d) and Apo-CIII (r = 3.34, p nonlinearity = 0.013) and Apo-CII (r = 1.09, p nonlinearity = 0.017) based on trial duration (weeks) in a nonlinear fashion.Based on our findings, supplements or fortified foods containing PS might have a considerable favorite effect in achieving Apo profile target; however, due to high heterogeneity among included studies, results must be interpreted with caution.KEY TEACHING POINTSCardiovascular diseases (CVDs) recognized as main public health concern worldwide with considerable mortality of all global deaths.Apo-lipoproteins are amphipathic molecules involved in the lipoprotein metabolism which introduced as biomarkers in the evaluation of CVD risk.Phytosterols bioactive components of plants have important biological functions in cholesterol metabolism in humans.Here we showed that phytosterols and phytostanols improve apo-lipoproteins profile of humans; finding from meta-analysis of randomized controlled trials.Phytosterols supplementation lowered atherogenic apo-lipoproteins (Apo-B and Apo-E) and increased anti-atherogenic apo-lipoproteins (Apo-AI, Apo-CII).

Rapid determination of phytosterols by NIRS and chemometric methods

Phytosterols have been extensively studied because it plays essential roles in the physiology of plants and can be used as nutritional supplement to promote human health. We use a rapid method by coupling near-infrared spectroscopy (NIRS) and chemometric techniques to quickly and efficiently determine three essential phytosterols (β-sitosterol, campesterol and stigmasterol) in vegetable oils. Continuous wavelet transform (CWT) method was adopted to remove the baseline shift in the spectra. The quantitative analysis models were constructed by partial least squares (PLS) regression and randomization test (RT) method was used to further improve the models. The optimized models were used to calculate the phytosterol contents in prediction set in order to evaluate their predictability. We have found that the phytosterol contents obtained by the optimized models and Gas Chromatography/Mass Spectrometry (GC/MS) analysis are almost consistent. The root mean square error of prediction (RMSEP) and ratio of prediction to deviation (RPD) for the three phytosterols are 525.7590, 212.2245, 65.1611 and 4.0060, 4.7195 and 3.5441, respectively. The results have proved the feasibility of the proposed method for rapid and non-destructive analysis of phytosterols in edible oils.

The Effect of Microwave Pretreatment on Micronutrient Contents, Oxidative Stability and Flavor Quality of Peanut Oil

The purpose of the present study is to investigate the changes in extraction yield, physicochemical properties, micronutrients content, oxidative stability and flavor quality of cold pressed peanut oil extracted from microwave (MW) treated seeds (0, 1, 2, 3, 4, 5 min, 700 W). The acid value and peroxide value of extracted oil from MW-treated peanuts were slightly increased but far below the limit in the Codex standard. Compared with the untreated sample, a significant (p < 0.05) increase in extraction yield (by 33.75%), free phytosterols content (by 32.83%), free tocopherols content (by 51.36%) and induction period (by 168.93%) of oil extracted from 5 min MW-treated peanut were observed. MW pretreatment formed pyrazines which contribute to improving the nutty and roasty flavor of oil. In conclusion, MW pretreatment is a feasible method to improve the oil extraction yield and obtain the cold pressed peanut oil with longer shelf life and better flavor.

The Effect of Microwave Pretreatment on Micronutrient Contents, Oxidative Stability and Flavor Quality of Peanut Oil

The purpose of the present study is to investigate the changes in extraction yield, physicochemical properties, micronutrients content, oxidative stability and flavor quality of cold pressed peanut oil extracted from microwave (MW) treated seeds (0, 1, 2, 3, 4, 5 min, 700 W). The acid value and peroxide value of extracted oil from MW-treated peanuts were slightly increased but far below the limit in the Codex standard. Compared with the untreated sample, a significant (p < 0.05) increase in extraction yield (by 33.75%), free phytosterols content (by 32.83%), free tocopherols content (by 51.36%) and induction period (by 168.93%) of oil extracted from 5 min MW-treated peanut were observed. MW pretreatment formed pyrazines which contribute to improving the nutty and roasty flavor of oil. In conclusion, MW pretreatment is a feasible method to improve the oil extraction yield and obtain the cold pressed peanut oil with longer shelf life and better flavor.

Bulk industrial fruit fibres. Characterization and prevalence of the original fruit metabolites

Here we analysed the content of primary and secondary metabolites in nine types of industrially processed fibres derived from the juice industry. Specifically, we examined fibre from: apple, peach, and pear, as non-citrus fruits; the peel and flesh of orange and tangerine, and lemon flesh, as citrus fruits; and carrot, as vegetable. Regarding primary metabolites, the sugar content ranged from 21.6 mg/g in lemon to 290 mg/g in orange peel and lower mass organic acid content ranged from 25.0 mg/g in pear to 250 mg/g in lemon. The content of fatty acids were constant during fibre processing, ranging from 0.5 to 1.46%. Furthermore, the fatty acid profile was not affect for the processing. Concerning secondary metabolites, industrial processing did not decrease the sterols content, which ranged from 0.51 to 1.66 μg/g. Regarding carotenoids, of note was the presence of epoxycarotenoids, which may reflect the quality of the industrial process, thus giving added value to the by-product.

Effect of gestational diabetes mellitus on newborn cholesterol metabolism

BACKGROUND AND AIMS

Impaired glucose metabolism during pregnancy may associate with changes in fetal cholesterol metabolism. We investigated if gestational diabetes mellitus (GDM) affects newborn cholesterol metabolism as determined by cord blood squalene and non-cholesterol sterols. Furthermore, we examined potential correlations between cord blood and maternal serum non-cholesterol sterols.

METHODS

Pregnant women at risk for GDM (BMI>30 kg/m²) were enrolled from maternity clinics in Finland. GDM was determined from the results of an oral glucose tolerance test. Serum samples were taken in the third trimester of pregnancy, and cord blood samples collected from their newborns at birth. Squalene and non-cholesterol sterols were analyzed from serum and cord blood by gas liquid chromatography. All women with GDM were in good glycaemic control.

RESULTS

The ratios of squalene and non-cholesterol sterols to cholesterol (100 × μmol/mmol of cholesterol) in cord blood did not differ between the infants born to mothers with GDM (n = 15) or mothers with normal glucose tolerance (n = 13). The ratios of sitosterol and campesterol to cholesterol in the cord blood correlated with the corresponding maternal serum ratios (r = 0.70, p < 0.0001) in both groups.

CONCLUSIONS

In obese women under good glycaemic control, GDM did not affect newborn cholesterol metabolism. Cord blood sitosterol and campesterol ratios to cholesterol correlated with the corresponding maternal serum ratios thus potentially reflecting maternal-fetal cholesterol transport.

Changes in 3-MCPD esters, glycidyl esters, bioactive compounds and oxidation indexes during kenaf seed oil refining

An optimized refining process for kenaf seed oil was conducted. The 3-monochloro-1,2-propanediol (3-MCPD) contents, triacylglycerol composition, fatty acids composition, bioactive compounds, phosphorus contents, and oxidation indexes of the kenaf seed oil during each stage of the refining process were determined. The results showed that there was no detected 3-MCPD ester in kenaf seed oil throughout the refining process. Deodorization had slightly increased the 2-MCPD ester (9.0 μg/kg) and glycidyl ester (54.8 μg/kg). Oleic (36.53%) and linoleic acids (36.52%) were presented in the largest amount in the refined kenaf seed oil, and triacylglycerols contributed to 99.96% in the oil. There was a removal of 31.6% of phytosterol content and 17.1% of tocopherol and tocotrienol contents in kenaf seed oil after refining. The refining process was totally removed the hydroperoxides, 93% of free fatty acids and 98.8% of phosphorus content in kenaf seed oil.

Protective effects of stigmasterol against ketamine-induced psychotic symptoms: Possible behavioral, biochemical and histopathological changes in mice

BACKGROUND

Stigmasterol, a naturally occurring phytoestrogen has been reported to possess many pharmacological activities. The aim of the present study was to screen the effect of stigmasterol against ketamine-induced mice model of psychosis.

METHODS

The behavioural studies included an assessment of locomotor activity, stereotypic behaviours, immobility duration, step down latency and effects on catalepsy. Biochemical estimations involved the estimations of GABA, dopamine, GSH, MDA, TNF-α, total protein content and AChE activity. Histopathological changes and effect on androgenic parameters were also evaluated.

RESULTS

Stigmasterol treated animals showed significant decrease in locomotor activity, stereotypic behaviours, immobility duration and increased step down latency. Biochemical estimations revealed increased GABA, GSH levels and decreased dopamine, MDA, TNF-α levels and AChE activity. These findings were confirmed by histopathological changes in the cortex part of the brain. Further, stigmasterol was not found to cause catalepsy and any adverse effect on the reproductive system.

CONCLUSION

This study concluded that stigmasterol could ameliorate ketamine-induced behavioral, biochemical and histopathological alterations in mice showing its potential effects in the management of psychotic symptoms.

Phytosterol-enriched milk lowers LDL-cholesterol levels in Brazilian children and adolescents: Double-blind, cross-over trial

BACKGROUND AND AIMS

Despite evidence of the lipid-lowering effect of plant sterols among adults with hypercholesterolemia, data regarding phytosterol use in children are limited. In this paper, we examined the effects of daily consumption of a phytosterol-enriched milk compound on the lipid profiles of Brazilian children and adolescents with dyslipidemia.

METHODS AND RESULTS

This was a randomized, double blind, crossover clinical trial. Twenty eight dyslipidemics outpatients (aged 6-9 years) from an University Hospital were randomly allocated to control or intervention group. The intervention group received milk enriched with 1.2 g/day of plant sterol and the control group received the equivalent amount of skim milk during the period of 8 weeks. Changes from baseline in the mean lipid profile, including total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and triglyceride (TG) concentrations. Serum lipid profiles, glucose levels, dietary and anthropometric data were determined at weeks 0, 4, 8, 16, and 20. Details regarding the safety and tolerance of phytosterol were obtained, using an open-ended questionnaire. Intention-to-treat analysis were performed, using the proc mixed procedure in SAS. After 8 weeks, the mean concentrations of TC and LDL-C were significantly reduced in the intervention group as compared to the control group with reductions of 5.9% (p = 0.09) and 10.2% (p = 0.002), respectively. In addition, TG concentrations were reduced by 19.7% (p = 0.09). No serious side effects were reported during the study.

CONCLUSION

Our results confirm that plant sterols are an effective and safe treatment of infantile dyslipidemia.

TRIAL REGISTRATION

RBR-3h7f9k.

Virus-induced gene silencing of the two squalene synthase isoforms of apple tree (Malus × domestica L.) negatively impacts phytosterol biosynthesis, plastid pigmentation and leaf growth

The use of a VIGS approach to silence the newly characterized apple tree SQS isoforms points out the biological function of phytosterols in plastid pigmentation and leaf development. Triterpenoids are beneficial health compounds highly accumulated in apple; however, their metabolic regulation is poorly understood. Squalene synthase (SQS) is a key branch point enzyme involved in both phytosterol and triterpene biosynthesis. In this study, two SQS isoforms were identified in apple tree genome. Both isoforms are located at the endoplasmic reticulum surface and were demonstrated to be functional SQS enzymes using an in vitro activity assay. MdSQS1 and MdSQS2 display specificities in their expression profiles with respect to plant organs and environmental constraints. This indicates a possible preferential involvement of each isoform in phytosterol and/or triterpene metabolic pathways as further argued using RNAseq meta-transcriptomic analyses. Finally, a virus-induced gene silencing (VIGS) approach was used to silence MdSQS1 and MdSQS2. The concomitant down-regulation of both MdSQS isoforms strongly affected phytosterol synthesis without alteration in triterpene accumulation, since triterpene-specific oxidosqualene synthases were found to be up-regulated to compensate metabolic flux reduction. Phytosterol deficiencies in silenced plants clearly disturbed chloroplast pigmentation and led to abnormal development impacting leaf division rather than elongation or differentiation. In conclusion, beyond the characterization of two SQS isoforms in apple tree, this work brings clues for a specific involvement of each isoform in phytosterol and triterpene pathways and emphasizes the biological function of phytosterols in development and chloroplast integrity. Our report also opens the door to metabolism studies in Malus domestica using the apple latent spherical virus-based VIGS method.

Oxidation of sitosterol and transport of its 7-oxygenated products from different tissues in humans and ApoE knockout mice

The most common phytosterols in the human diet are sitosterol and campesterol, which originate exclusively from plant derived food. These phytosterols are taken up by NPC1L1 transport from the intestine into the enterocytes together with cholesterol and other xenosterols. Phytosterols are selectively pumped back from the enterocytes into the intestinal lumen and on the liver site from hepatocytes into bile by heterodimeric ABCG5/G8 transporters. Like cholesterol, both phytosterols are prone to ring and side chain oxidation. It could be shown that oxyphytosterols, found in atherosclerotic tissue, are most likely of in situ oxidation (Schött et al.; Biochem. Biophys. Res. Commun. 2014 Apr 11;446(3):805-10). However, up to now, the entire mechanism of phytosterol oxidation is not clearly understood. Here, we provide further information about the oxidation of sitosterol and the transport of its oxidation products out of tissue. Our survey includes data of 104 severe aortic stenosis patients that underwent an elective aortic valve cusp replacement. We studied their phytosterol concentrations, as well as absolute and substrate corrected oxyphytosterol levels in plasma and valve cusp tissue. In addition, we also examined phytosterol and oxyphytosterol concentrations in plasma and tissues (from brain and liver) of 10 male ApoE knockout mice. The ratio of 7-oxygenated-sitosterol-to-sitosterol exceeds the ratio for 7-oxygenated-campesterol-to-campesterol in plasma and tissue of both humans and mice. This finding indicates that sitosterol is oxidized to a higher amount than campesterol and that a selective oxidative mechanism might exist which can differentiate between certain phytosterols. Secondly, the concentrations of oxyphytosterols found in plasma and tissue support the idea that oxysitosterols are preferably transported out of individual tissues. Selective oxidation of sitosterol and preferred transport of sitosterol oxidation products out of tissue seem to be a metabolic pathway of forced sitosterol clearance from tissue compartments.

Steroid Bioconversions

Steroid modifications by selected wild-type and engineered strains of microorganisms became an effective tool for the production of high-valued steroidal drugs and their precursors for the pharmaceutical industry. Some microorganisms are effective at the performance of sterol side-chain degradation, oxyfunctionalization of steroid core, and redox reactions at different positions of the steroid molecule. A number of bioprocesses using steroid-transforming microbial strains are well established on an industrial level. Although a range of biocatalytic methods has been developed, selection of suitable microorganisms, as well as creation of new engineered strains, is of great importance for generation of improved bioprocesses and production schemes for obtaining known and new metabolites with potent biological activity. The achievements in genetic and metabolic engineering of steroid-transforming strains in combination with novel approaches in the enzymatic and whole-cell biocatalysis provide a platform for highly effective and selective biotransformations.Here, we briefly review the current state and prospects in the field of microbial bioconversions with special attention to the application of molecular microbiology methods for the generation of new whole cell biocatalysts.

Obtaining of 11α-Hydroxyandrost-4-ene-3,17-dione from Natural Sterols

Two-step one-pot microbial transformation enables obtaining of valuable steroids that are difficult to produce chemically. Here we describe a method for obtaining 11α-hydroxyandrost-4-ene-3,17-dione (11α-HAD) from cheap and available natural sterols (phytosterols or cholesterol).11α-HAD is a primary adrenal steroid in mammals and also a key precursor in the syntheses of halogenated corticoids. Conventional routes for its obtaining are based on chemical synthesis, or microbial hydroxylation of androst-4-ene-3,17-dione (AD). AD in turn is produced primarily with microbial biotransformation of natural sterols by some actinobacteria.Consequent bioconversions of sterols using two microbial strains in one bioreactor vessel without separation and purification of AD provides high yield of 11α-HAD. At the first fermentation step, phytosterol is converted to AD with Mycobacterium neoaurum NRRL 3805B, or relative strains, to yield about 70% (mol/mol). At the second step, AD is almost fully (98%) hydroxylated at the position 11α with Aspergillus ochraceus VKM F-830, or other suitable organisms, in the same bioreactor. At the average, 30% (w/w) of the high-purity crystalline 11α-HAD can be obtained.The method can be exploited for production of 11α-HAD for practical use.

Rapid measurement of phytosterols in fortified food using gas chromatography with flame ionization detection

A novel method for the measurement of total phytosterols in fortified food was developed and tested using gas chromatography with flame ionization detection. Unlike existing methods, this technique is capable of simultaneously extracting sterols during saponification thus significantly reducing extraction time and cost. The rapid method is suitable for sterol determination in a range of complex fortified foods including milk, cheese, fat spreads, oils and meat. The main enhancements of this new method include accuracy and precision, robustness, cost effectiveness and labour/time efficiencies. To achieve these advantages, quantification and the critical aspects of saponification were investigated and optimised. The final method demonstrated spiked recoveries in multiple matrices at 85-110% with a relative standard deviation of 1.9% and measurement uncertainty value of 10%.

The effect of phytosterol protects rats against 4-nitrophenol-induced liver damage

We investigated the effect of phytosterol (PS) in regard to liver damage induced by 4-nitrophenol (PNP). Twenty rats were randomly divided into four groups (Control, PS, PNP, and PNP+PS). The PS and PNP+PS groups were pretreated with PS for one week. The PNP and PNP+PS groups were injected subcutaneously with PNP for 28 days. The control group received a basal diet and was injected with vehicle alone. Treatment with PS prevented the elevation of the total bilirubin levels, as well as an increase in serum alkaline transaminase and aspartate transaminase, which are typically caused by PNP-induced liver damage. Histopathologically showed that liver damage was significantly mitigated by PS treatment. However, there was no significant change in antioxidant enzyme activities, and the Nrf2-antioxidant system was not activated after treatment with PS. These results suggest that PS could mitigate liver damage induced by PNP, but does not enhance antioxidant capacity.

Rice phytochemicals concentrated by molecular distillation process and their use as co-surfactant in water dispersion

This study investigated the effects of evaporating temperature during molecular distillation (MD) process employed to deodorizer distillate (DD) on the retention of rice phytochemicals in the unevaporated fraction (UMDs), which were then further used as co-surfactants in the fabrication of water-dispersible vesicles. The pilot-scale MD unit was operated at 120, 140 or 160 °C and 0.1 Pa to concentrate rice phytosterols from 1540.8 mg in 100 g DD to 3990.2-4904.8 mg in 100 g UMDs by evaporating out free fatty acids. Although γ-oryzanol content was increased from 598.9 mg in 100 g DD to 870.0-1018.1 mg in 100 g UMDs when the temperature was raised to 160 °C, such high temperature decreased tocols from 2185.7 mg in 100 g DD to 850.5 mg in 100 g UMDs and antioxidant capacity of UMDs measured as 2,2-diphenyl-1-picrylhydrazyl scavenging capacity. The UMD obtained after distillation at 140 °C was used as co-surfactant with soy lecithin, sucrose palmitate or polyoxyethylene sorbitan monooleate (Tween 80) to fabricate vesicles in pH 7.0 phosphate buffered saline (PBS). This study showed potential use of the UMD as a source of rice phytochemicals and a co-surfactant when used with Tween80 in small vesicle fabrication. The fabricated Tween 80/UMD vesicles in PBS had the size range of 200-300 nm and were stable within a temperature range of 4 to 37 °C for 96 h.

Identification and characterization of β-sitosterol target proteins

β-Sitosterol is the most abundant plant sterol in the human diet. It is also the major component of several traditional medicines, including saw palmetto and devil's claw. Although β-sitosterol is effective against enlarged prostate in human clinical trials and has anti-cancer and anti-inflammatory activities, the mechanisms of action are poorly understood. Here, we report the identification of two new binding proteins for β-sitosterol that may underlie its beneficial effects.

Cytotoxic and natural killer cell stimulatory constituents of Phyllanthus songboiensis

A dichapetalin-type triterpenoid and a dibenzylbutyrolactone-type lignan, together with five known lignans, a known aromatic diterpenoid, and a known acylated phytosterol, were isolated from the aerial parts of Phyllanthus songboiensis, collected in Vietnam. Their structures were determined by interpretation of the spectroscopic data, and the inhibitory activity toward HT-29 human colon cancer cells of all isolates was evaluated by a cytotoxicity assay. The known arylnaphthalene lignan, (+)-acutissimalignan A, was highly cytotoxic toward HT-29 cells, with an IC50 value of 19 nM, but this compound was inactive as a DNA topoisomerase IIα (topo IIα) poison. The known phytosterol, (-)-β-sitosterol-3-O-β-D-(6-O-palmitoyl)glucopyranoside, was found to stimulate natural killer (NK) cells at a concentration of 10μM in the presence of interleukin 12 (IL-12).

Content of carotenoids, tocopherols, sterols, triterpenic and aliphatic alcohols, and volatile compounds in six walnuts (Juglans regia L.) varieties

The aim of this work was to study the content of tocopherols, sterols, triterpenic and aliphatic alcohols, carotenoids, and volatile compounds in the kernel oils from six walnut (Juglans regia L.) varieties. The levels of β-carotene ranged between 0.22 and 0.62 mg/kg, followed by lutein (0.01-0.06 mg/kg). The total content of tocopherol ranged from 186.5 to 436.2 mg/kg of the extracted oil and the major isoform in all samples was γ-tocopherol. The most abundant phytosterol was β-sitosterol (974-1494 mg/kg) followed by campesterol then Δ-5-avenasterol. The major triterpenic alcohol was cycloartenol (226.4-532.1 mg/kg). Hexacosanol (9.71-28.15 mg/kg) was the major aliphatic alcohol. The detected volatile compounds were pentanal, hexanal, nonanal, 2-decenal and hexanol. The statistical analysis showed significant differences between varieties, which are probably due to genetic factors.

Rheological and physical properties of yogurt enriched with phytosterol during storage

Phytosterols enriched products are innovative types of functional foods, in which dairy products, like low fat yogurt are ideal vehicles for this functional component. In this study, phytosterol dispersions were prepared using an oil/water (O/W) emulsion. The emulsion was added to yogurt milk. pH, titratable acidity (TA), syneresis, firmness and apparent viscosity of enriched yogurt were determined during storage. Moreover, phytosterols distribution in different parts of enriched yogurt was studied. Results indicated that in enriched yogurt, apparent viscosity and syneresis were lower and firmness was higher compared to the control. Addition of phytosterol to the yogurt had significant effect on acidity. Distribution of phytosterols in different parts of one sample was not uniform. Sensory results showed that there was no significant difference between enriched and control on texture, appearance, flavor and overall acceptance.

Dietary supplementation contributes to lifestyle improvement in hypercholesterolemic patients in real-life contexts

AIMS

Assess the evolution of cardiovascular lifestyle behaviors in hypercholesterolemic patients concomitantly with changes in their daily intake of phytosterol-supplemented yoghurt (Phyto-SY).

METHODS

Nationwide prospective observational study conducted in general practices across France and Spain. Each practitioner suggested lifestyle changes to five consecutive patients with hypercholesterolemia (whether or not they were taking hypocholesterolemic drugs) and recommended daily consumption of Phyto-SY. The study design involved an inclusion visit, a patient's self-monitoring assessment after 1 month, and a final visit after 4 months. Primary evaluation criterion: changes in dietary habits assessed by a standardized Nutritional Lifestyle score. Secondary criteria: changes in lipid profile, anthropometry (waist circumference) and lifestyle behavior.

RESULTS

A total of 2376 hypercholesterolemic patients (of whom 54.8% were women) were included. The average age was 56.2 years old. The Nutritional Lifestyle score improved from 15.4 ± 5.4 to 8.7 ± 4.0 (p < 0.0001). Total cholesterol decreased by 10.6% (<0.0001), HDL-C increased by 8.0% (<0.0001), and LDL-C fell by 12.7% (<0.0001). Similar results were observed in patients treated with statins and those who were not. Frequency of walking (>30 min) increased from 59.3% to 78.3% (p < 0.0001). The overweight rate decreased from 22.8% to 17.5% (p < 0.0001) and waist circumference from 94.6 ± 13.3 cm to 93.0 ± 12.8 cm (p < 0.0001). Nutritional Lifestyles and other lifestyle markers' improvement were parallel to adherence to Phyto-SY adherence.

CONCLUSION

Improvements in Nutritional Lifestyle scores, which included regular consumption of Phyto-SY over 4 months, was significantly linked to healthier lifestyles and to beneficial modifications in atherogenic lipid profiles, which reflected patient empowerment in a 'real life' context.

A method for simultaneous analysis of phytosterols and phytosterol esters in tobacco leaves using non aqueous reversed phase chromatography and atmospheric pressure chemical ionization mass spectrometry detector

While numerous analytical methods for phytosterols have been reported, the similar polarity and large molecules of phytosterol esters have made the methods lengthy and complicated. For this reason, an analytical method that could completely separate phytosterol esters including the higher fatty acids such as palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid in addition to phytosterols without preliminary separation was developed. The separation was accomplished by non-aqueous reversed phase chromatography technique using only acetone and acetonitrile. An atmospheric pressure chemical ionization/mass spectrometry detector configured at selected ion monitoring mode was hyphenated with the separation system to detect phytosterols and phytosterol esters. Twenty-four types of these were consequently separated and then identified with their authentic components. The calibration curve was drawn in the range of about 5 to 25,000 ng/mL with a regression coefficient over 0.999. The limit of detection and limit of quantification, respectively, ranged from 0.9 to 3.0 ng/mL and from 3.0 to 11.0 ng/mL. Recovery rates ranged from 80 to 120%. The quantification results were subjected to statistical analysis and hierarchical clustering analysis, and were used to determine the differences in the amounts of phytosterols and phytosterol esters across tobacco leaves. The newly developed method succeeded in clarifying the whole composition of phytosterols and phytosterol esters in tobacco leaves and in explaining compositional differences across the variety of tobacco leaves.

Quality and characteristics of ginseng seed oil treated using different extraction methods

Ginseng seed oil was prepared using compressed, solvent, and supercritical fluid extraction methods of ginseng seeds, and the extraction yield, color, phenolic compounds, fatty acid contents, and phytosterol contents of the ginseng seed oil were analyzed. Yields were different depending on the roasting pretreatment and extraction method. Among the extraction methods, the yield of ginseng seed oil from supercritical fluid extraction under the conditions of 500 bar and 65℃ was the highest, at 17.48%. Color was not different based on the extraction method, but the b-value increased as the roasting time for compression extraction was increased. The b-values of ginseng seed oil following supercritical fluid extraction were 3.54 to 15.6 and those following compression extraction after roasting treatment at 200℃ for 30 min, were 20.49, which was the highest value. The result of the phenolic compounds composition showed the presence of gentisic acid, vanillic acid, ferulic acid, and cinnamic acid in the ginseng seed oil. No differences were detected in phenolic acid levels in ginseng seed oil extracted by compression extraction or solvent extraction, but vanillic acid tended to decrease as extraction pressure and temperature were increased for seed oil extracted by a supercritical fluid extraction method. The fatty acid composition of ginseng seed oil was not different based on the extraction method, and unsaturated fatty acids were >90% of all fatty acids, among which, oleic acid was the highest at 80%. Phytosterol analysis showed that β-sitosterol and stigmasterol were detected. The phytosterol content of ginseng seed oil following supercritical fluid extraction was 100.4 to 135.5 mg/100 g, and the phytosterol content following compression extraction and solvent extraction was 71.8 to 80.9 mg/100 g.

Special lipid-based diets alleviate cognitive deficits in the APPswe/PS1dE9 transgenic mouse model of Alzheimer's disease independent of brain amyloid deposition

Dietary fish oil, providing n3 polyunsaturated fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), associates with reduced dementia risk in epidemiological studies and reduced amyloid accumulation in Alzheimer mouse models. We now studied whether additional nutrients can improve the efficacy of fish oil in alleviating cognitive deficits and amyloid pathology in APPswe/PS1dE9 transgenic and wild-type mice. We compared four isocaloric (5% fat) diets. The fish oil diet differed from the control diet only by substituted fish oil. Besides fish oil, the plant sterol diet was supplemented with phytosterols, while the Fortasyn diet contained as supplements precursors and cofactors for membrane synthesis, viz. uridine-monophosphate; DHA and EPA; choline; folate; vitamins B6, B12, C and E; phospholipids and selenium. Mice began the special diets at 5 months and were sacrificed at 14 months after behavioral testing. Transgenic mice, fed with control chow, showed poor spatial learning, hyperactivity in exploring a novel cage and reduced preference to explore novel odors. All fish-oil-containing diets increased exploration of a novel odor over a familiar one. Only the Fortasyn diet alleviated the spatial learning deficit. None of the diets influenced hyperactivity in a new environment. Fish-oil-containing diets strongly inhibited β- and γ-secretase activity, and the plant sterol diet additionally reduced amyloid-β 1-42 levels. These data indicate that beneficial effects of fish oil on cognition in Alzheimer model mice can be enhanced by adding other specific nutrients, but this effect is not necessarily mediated via reduction of amyloid accumulation.

Comparative analysis of genes encoding key steroid core oxidation enzymes in fast-growing Mycobacterium spp. strains

A comparative genome analysis of Mycobacterium spp. VKM Ac-1815D, 1816D and 1817D strains used for efficient production of key steroid intermediates (androst-4-ene-3,17-dione, AD, androsta-1,4-diene-3,17-dione, ADD, 9α-hydroxy androst-4-ene-3,17-dione, 9-OH-AD) from phytosterol has been carried out by deep sequencing. The assembled contig sequences were analyzed for the presence putative genes of steroid catabolism pathways. Since 3-ketosteroid-9α-hydroxylases (KSH) and 3-ketosteroid-Δ(1)-dehydrogenase (Δ(1) KSTD) play key role in steroid core oxidation, special attention was paid to the genes encoding these enzymes. At least three genes of Δ(1) KSTD (kstD), five genes of KSH subunit A (kshA), and one gene of KSH subunit B of 3-ketosteroid-9α-hydroxylases (kshB) have been found in Mycobacterium sp. VKM Ac-1817D. Strains of Mycobacterium spp. VKM Ac-1815D and 1816D were found to possess at least one kstD, one kshB and two kshA genes. The assembled genome sequence of Mycobacterium sp. VKM Ac-1817D differs from those of 1815D and 1816D strains, whereas these last two are nearly identical, differing by 13 single nucleotide substitutions (SNPs). One of these SNPs is located in the coding region of a kstD gene and corresponds to an amino acid substitution Lys (135) in 1816D for Ser (135) in 1815D. The findings may be useful for targeted genetic engineering of the biocatalysts for biotechnological application.

Dietary phytosterol does not accumulate in the arterial wall and prevents atherosclerosis of LDLr-KO mice

SCOPE

There have been conflicting reports on the usefulness of phytosterols (PS) in preventing atherosclerosis. We evaluated the effects of dietary PS supplementation in LDLr-KO male mice on the plasma and aorta sterol concentrations and on atherosclerotic lesion development.

METHODS AND RESULTS

Mice were fed a high fat diet (40% of energy) supplemented with or without PS (2% w/w, n = 10). Plasma and arterial wall cholesterol and PS concentrations, lesion area, macrophage infiltration, and mRNA expression from LOX-1, CD36, ABCA1 and ABCG1 in peritoneal macrophages were measured. After 16 weeks, the plasma cholesterol concentration in PS mice was lower than that in the controls (p = 0.02) and in the arterial wall (p = 0.03). Plasma PS concentrations were higher in PS-fed animals than in controls (p < 0.0001); however, the arterial wall PS concentration did not differ between groups. The atherosclerotic lesion area in the PS group (n = 5) was smaller than that in controls (p = 0.0062) and the macrophage area (p = 0.0007). PS correlates negatively with arterial lipid content and macrophage (r = -0.76; p < 0.05). PS supplementation induced lower ABCG1 mRNA expression (p < 0.05).

CONCLUSIONS

Despite inducing an increase in PS plasma concentration, PS supplementation is not associated with its accumulation in the arterial wall and prevents atherosclerotic lesion development.

Rhizomes of Eremostachys laciniata: Isolation and Structure Elucidation of Chemical Constituents and a Clinical Trial on Inflammatory Diseases

PURPOSE

The purpose of this study was the isolation and structure elucidation of chemical compounds from the rhizomes of Eremostachys laciniata (L) Bunge (EL), an Iranian traditional medicinal herb with a thick root and pale purple or white flowers as well as the clinical studies on the therapeutic efficacy and safety of topical application of the EL extract in the management of some inflammatory conditions, e.g., arthritis, rheumatoid arthritis and septic arthritis (Riter's syndrome).

METHODS

The structures of the isolated compounds were elucidated unequivocally on the basis of one and two dimensional NMR, UV and HR-FABMS spectroscopic data analyses. A single-blinded randomized clinical trial was carried out with the extract of the rhizomes of E. laciniata (EL) to determine the efficacy and safety of the traditional uses of EL compared to that of piroxicam in treatment of inflammatory diseases, e.g., osteoarthritis, rheumatoid arthritis and Reiter's syndrome.

RESULTS

Eleven iridoid glycosides, two phenylethanoids and two phytosterols were isolated and identified for the first time from the rhizomes of EL. After 14 days of treatment with the EL and piroxicam ointments, all groups showed significant improvements compared to the control groups. EL (5%) ointment induced better initial therapeutic response than piroxicam (5%) onitment.

CONCLUSION

This clinical trial established that EL was suitable for topical applications as a safe and effective complementary therapy for inflammatory diseases.

Inhibition of Escherichia coli O157:H7 motility and biofilm by β-sitosterol glucoside

BACKGROUND

Escherichia coli O157:H7 (EHEC) is a food borne pathogen, which causes diarrhea and hemolytic uremic syndrome (HUS). There is an urgent need of novel antimicrobials for treatment of EHEC as conventional antibiotics enhance shiga toxin production and potentiate morbidity and mortality.

METHODS

Six bioactive compounds were isolated, identified from citrus and evaluated for the effect on EHEC biofilm and motility. To determine the possible mode of action, a series of genes known to affect biofilm and motility were overexpressed and the effect on biofilm/motility was assessed. Furthermore, the relative expression of genes involved in motility and biofilm formation was measured by qRT-PCR in presence and absence of phytochemicals, to examine the repression caused by test compounds.

RESULTS

The β-sitosterol glucoside (SG) was identified as the most potent inhibitor of EHEC biofilm formation and motility without affecting the cell viability. Furthermore, SG appears to inhibit the biofilm and motility through rssAB and hns mediated repression of flagellar master operon flhDC.

CONCLUSION

SG may serve as novel lead compound for further development of anti-virulence drugs.

GENERAL SIGNIFICANCE

Plant sterols constitute significant part of diet and impart various health benefits. Here we present the first evidence that SG, a plant sterol has significant effect on EHEC motility, a critical virulence factor, and may have potential application as antivirulence strategy.