Proteomic study of gamma-oryzanol preventive effect on a diet-induced non-alcoholic fatty liver disease model

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease associated with obesity and diabetes prevalence. The use of natural compounds has become an attractive approach to prevent NAFLD and its progression. Gamma-oryzanol (Orz) is a natural compound whose beneficial effects on chronic metabolic diseases have been reported. Therefore, we aimed to investigate the preventive effect of Orz on the hepatic proteome in a diet induced NAFLD model. Wistar rats were randomly distributed into three experimental groups (n=6/group) according to the diet received for 30 weeks: Control group, high sugar-fat (HSF) group, and HSF+Orz group. The isolated Orz was added to the chow at the dose of 0.5% (w/w). We evaluated the nutritional profile, characterized the presence of steatosis through histological analysis, triglyceride content in liver tissue and hepatic inflammation. Next, we performed label-free quantitative proteomics of hepatic tissue. Network analysis was performed to describe involved protein pathways. NAFLD induction was characterized by the presence of hepatic steatosis. Orz prevented lipid accumulation. The compound prevented alterations of the hepatic proteome, highlighted by the modulation of lipid metabolism, inflammation, oxidative stress, xenobiotic metabolism, and the sirtuin signaling pathway. It was possible to identify key altered pathways of NAFLD pathophysiology modulated by Orz which may provide insights into NAFLD treatment targets.

Differential regulation of key triterpene synthase gene under abiotic stress in Withania somnifera L. Dunal and its co-relation to sterols and withanolides

Withania somnifera (Ashwagandha), is one of the most reputed Indian medicinal plants, having immense pharmacological activities due to the occurrence of withanolides. The withanolides are biosynthesized through triterpenoid biosynthetic pathway with the involvement of WsCAS leading to cyclization of 2, 3 oxidosqualene, which is a key metabolite to further diversify to a myriad of phytochemicals. In contrast to the available reports on the studies of WsCAS in withanolide biosynthesis, its involvement in phytosterol biosynthesis needs investigation. Present work deals with the understanding of role of WsCAS triterpenoid synthase gene in the regulation of biosynthesis of phytosterols & withanolides. Docking studies of WsCAS protein revealed Conserved amino acids, DCATE motif, and QW motif which are involved in efficient substrate binding, structure stabilization, and catalytic activity. Overexpression/silencing of WsCAS leading to increment/decline of phytosterols confers its stringent regulation in phytosterols biosynthesis. Differential regulation of WsCAS on the metabolic flux towards phytosterols and withanolide biosynthesis was observed under abiotic stress conditions. The preferential channelization of 2, 3 oxidosqualene towards withanolides and/or phytosterols occurred under heat/salt stress and cold/water stress, respectively. Stigmasterol and β-sitosterol showed major contribution in high/low temperature and salt stress, and campesterol in water stress management. Overexpression of WsCAS in Arabidopsis thaliana led to the increment in phytosterols in general. Thus, the WsCAS plays important regulatory role in the biosynthetic pathway of phytosterols and withanolides under abiotic stress conditions.

Identification of Adulteration of Flaxseed Oil From QINGHAI Area Using GC-MS Profiling of Phytosterol Composition and Chemometrics

Flaxseed oil is an important source of vegetable oil with a polyunsaturated fatty acid. It is significant to establish a method to quickly identify adulterated flaxseed oil. In the present study, the qualitative and quantitative analysis of phytosterol of flaxseed oil from different varieties and different production areas in the Qinghai area was first performed by gas chromatography-mass spectrometry (GC-MS) and the phytosterol standard profile of flaxseed oil was established. Then, a combination of similarity evaluation and cluster analysis was used to distinguish pure flaxseed oil from flaxseed oil adulterated with concentrations of 10-50% rapeseed oil, peanut oil, sunflower oil, and sesame oil, and discriminant analysis was used to identify the types of adulterated flaxseed oil. The results showed that similarity evaluation combined with cluster analysis can distinguish pure and adulterated flaxseed oil when the concentration of the adulterant was greater than 10%. Discriminant analysis models accurately identified the types of adulterating oil in flaxseed oil when the concentration of rapeseed, peanut, or sunflower oil was greater than 20%, and that of sesame oil was greater than 30%. This study shows that the determination of the phytosterol composition and chemometrics is a valuable tool to evaluate the purity of flaxseed oil.

Oxy- and Phytosterols as Biomarkers: Current Status and Future Perspectives

Oxysterols and phytosterols are sterol compounds present at markedly low levels in tissues and serum of healthy individuals. A wealth of evidence suggests that they could be employed as biomarkers for human diseases or for cholesterol absorption.An increasing number of reports suggest circulating or tissue oxysterols as putative biomarkers for cardiovascular and neurodegenerative diseases or cancers. Thus far most of the studies have been carried out on small study populations. To achieve routine biomarker use, large prospective cohort studies are absolutely required. This, again, would necessitate thorough standardization of the oxysterol analytical methodology across the different laboratories, which now employ different technologies resulting in inconsistencies in the measured oxysterol levels. Routine use of oxysterol biomarkers would also necessitate the development of a new targeted analytical methodology suitable for high-throughput platforms.The most important use of phytosterols as biomarkers involves their use as markers for cholesterol absorption. For this to be achieved, (1) their quantitative analyses should be available in routine lipid laboratories, (2) it should be generally acknowledgment that the profile of cholesterol metabolism can reveal the risk of the development of atherosclerotic cardiovascular diseases (ASCVD), and (3) screening of the profile of cholesterol metabolism should be included in the ASCVD risk surveys. This should be done e.g. in families with a history of early onset or frequent ASCVD and in young adults aged 18-20 years, to exclude the presence of high cholesterol absorption. Individuals in high cholesterol absorption families need preventive measures from young adulthood to inhibit the possible development and progression of atherosclerosis.

Lipidomics insight on differences in lipid profiles and phytosterol compositions of coconut oils extracted by classical and green solvents

Searching for green and ecofriendly solvents to replace classical solvents for industrial scale extraction of coconut oil is of great interest. To explore these possibilities, this study performed comprehensive comparative analyses of lipid profiles and phytosterol compositions in coconut oils obtained by extraction with n-hexane, absolute ethyl alcohol, deep eutectic solvent/n-hexane, dimethyl carbonate (DME) and cyclopentyl methyl ether (CPME) using a foodomics approach. Results indicated that CPME (64.23 g/100 g dry matter) and DME (65.64 g/100 g dry matter) showed comparable capacity for total lipid extraction of total lipids to classical solvents (63.5-65.66 g/100 g dry matter). Considering the phytosterol yield, CPME (644.26 mg/kg) exhibited higher selectivity than other solvents (535.64-622.13 mg/kg). No significant difference was observed in the fatty acid composition of coconut oil by the different solvents assayed. Additionally, total 468 lipid molecules were identified in the samples. For glycerolipid and sphingolipid, the five solvents showed comparable extraction capabilities. However, CPME exhibited higher extraction efficiency of polar lipids (glycerophospholipid and saccharolipid) than other solvents. Overall, these results may be a useful guide for the application of green solvents in industrial production of coconut oil.

Phytosterol conversion into C9 non-hydroxylated derivatives through gene regulation in Mycobacterium fortuitum

Androst-4-ene-3,17-dione (AD) and 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC) are important drug intermediates that can be biosynthesized from phytosterols. However, the C9 hydroxylation of steroids via 3-ketosteroid 9α-hydroxylase (KSH) limits AD and 4-HBC accumulation. Five active KshAs, the oxidation component of KSH, were identified in Mycobacterium fortuitum ATCC 35855 for the first time. The deletion of kshAs indicated that the five KshA genes were jointly responsible for C9 hydroxylation during phytosterol biotransformation. MFKDΔkshA, the five KshAs deficient strain, blocked C9 hydroxylation and produced 5.37 g/L AD and 0.55 g/L 4-HBC. The dual function reductase Opccr knockout and 17β-hydroxysteroid dehydrogenase Hsd4A enhancement reduced 4-HBC content from 8.75 to 1.72% and increased AD content from 84.13 to 91.34%, with 8.24 g/L AD being accumulated from 15 g/L phytosterol. In contrast, hsd4A and thioesterase fadA5 knockout resulted in the accumulation of 5.36 g/L 4-HBC from 10 g/L phytosterol. We constructed efficient AD (MFKDΔkshAΔopccr_hsd4A) and 4-HBC (MFKDΔkshAΔhsd4AΔfadA5) producers and provided insights for further metabolic engineering of the M. fortuitum ATCC 35855 strain for steroid productions. KEY POINTS: • Five active KshAs were first identified in M. fortuitum ATCC 35855. • Deactivation of all five KshAs blocks the steroid C9 hydroxylation reaction. • AD or 4-HBC production was improved by Hsd4A, FadA5, and Opccr modification.

Control Phytophagous Nematodes By Engineering Phytosterol Dealkylation Caenorhabditis elegans as a Model

Plant-parasitic nematodes ingest and convert host phytosterols via dealkylation to cholesterol for both structural and hormonal requirements. The insect 24-dehydrocholesterol reductase (DHCR24) was shown in vitro as a committed enzyme in the dealkylation via chemical blocking. However, an increased brood size and ovulation rate, instead compromised development, were observed in the engineered nematode Caenorhabditis elegans where the DHCR24 gene was knocked down, indicating the relationship between DHCR24 and dealkylation and their function in nematodes remains illusive. In this study, a defect in C. elegans DHCR24 causes impaired growth of the nematode with sitosterol (a major component of phytosterols) as a sole sterol source. Plant sterols with rationally designed structure (null substrates for dealkylation) can't be converted to cholesterol in wild-type worms, and their development was completely halted. This study underpins the essential function of DHCR24 in nematodes and would be beneficial for the development of novel nematocidal strategies.

Phytochemistry and biological activity of Erigeron annuus (L.) Pers

Erigeron annuus L. is a flowering herb of North America, Europe, Asia and Russia. This plant is used as folk medicine in China for the cure of indigestion, enteritis, epidemic hepatitis, haematuria and diabetes. Phytochemical studies showed the presence of 170 bioactive compounds like coumarins, flavonoids, terpenoids, polyacetylenic compounds; γ-pyrone derivatives, sterols and various caffeoylquinic acids derived from the essential oil and organic extracts from its various parts such as aerial parts, roots, leaves, stems and flowers. The pharmacological studies demonstrated various extracts and the compounds of E. annuus to exhibit anti-fungal, anti-atherosclerosis, anti-inflammatory, antidiabetic, phytotoxic, cytoprotective, antiobesity and antioxidant activities. This article covers a critical compendious on geographical distribution, botanical description, phytochemistry, ethnomedicinal uses and pharmacological activities of E. annuus. However, further in-depth studies are needed to determine the medical uses of E. annuus and its chemical constituents, pharmacological activities and clinical applications.

Sitosterol-rich Digera muricata against 7-ketocholesterol and lipopolysaccharide-mediated atherogenic responses by modulating NF-ΚB/iNOS signalling pathway in macrophages

Digera muricata L., commonly known as Tartara, is an edible herb used as traditional medicine in many countries of Africa and Asia. This study aimed to elucidate the effect of a phytosterol-rich extract of D. muricata on 7-ketocholesterol-mediated atherosclerosis in macrophages. The extract was examined by phytochemical analyses, GC-MS, TLC, DPPH scavenging and hRBC membrane stabilization assays. Macrophage polarization was studied with experimental groups framed based on alamar blue cell viability and griess assays. Regulations of arginase enzyme activity, ROS generation, mitochondrial membrane potential, cell membrane integrity, pinocytosis, lipid uptake and peroxidation, as well as, intracellular calcium deposition were determined. In addition, expressions of atherogenic mediators were analysed using PCR, ELISA and immunocytochemistry techniques. Diverse phytochemicals with higher free radical scavenging activity and anti-inflammatory potential have been detected in the D. muricata. Co-treatment with D. muricata markedly reduced the atherogenic responses induced by 7KCh in the presence of LPS such as ROS, especially, NO and O2- along with lipid peroxidation. Furthermore, D. muricata significantly normalized mitochondrial membrane potential, cell membrane integrity, pinocytic activity, intracellular lipid accumulation and calcium deposition. These results provided us with the potentiality of D. muricata in ameliorating atherogenesis. Additionally, it decreased the expression of pro-atherogenic mediators (iNOS, COX-2, MMP9, IL-6, IL-1β, CD36, CD163 and TGFβ1) and increased anti-atherogenic mediators (MRC1 and PPARγ) with high cellular expressions of NF-κB and iNOS. Results showed the potential of sitosterol-rich D. muricata as a versatile biomedical therapeutic agent against abnormal macrophage polarization and its associated pathologies.

Plant-based diet and its effect on coronary artery disease: A narrative review

Coronary artery disease (CAD), a primary component of cardiovascular diseases, is one of the top contributors to mortality rates worldwide. In 2021, dietary risk was estimated to be attributed to 6.58 million cardiovascular deaths. Plant-based diets (PBDs), which encourage higher consumption of plant foods and lower intake of animal-based foods, have been shown to reduce the risk of CAD by up to 29% when compared to non-vegetarian diets in a meta-analysis. This article aims to summarize the array of PBDs and compare them with conventional Western diets that include meat. We review the various proposed mechanisms for how the bioactive nutrients of PBDs aid in preventing atherosclerosis and CAD events, as well as other cardiac diseases. We conducted a detailed search of PubMed using our exclusive search strategy using the keywords plant-based diet, vegan diet, phytosterols, CAD, myocardial ischemia, and atherosclerosis. A total of 162 pertinent articles published within the past decade were identified for qualitative synthesis. To ensure the accuracy and reliability of our review, we included a total of 55 full-text, peer-reviewed articles that demonstrated the effects of plant-based diets on CAD and were written in English. We excluded animal studies, in vitro or molecular studies, and non-original data like editorials, letters, protocols, and conference abstracts. In this article, we emphasize the importance of dietary interventions, such as PBDs, to prevent CAD and their benefits on environmental sustainability. Integrating plant foods and whole grains into one's daily eating habits leads to an increase in the intake of nutrient-rich foods while reducing the consumption of processed food could not only prevent millions of premature deaths but also provide prevention against many chronic gastrointestinal and metabolic diseases.

Chemical conversions of free phytosterols during the bleaching of corn oil

Phytosterols have health benefits; however, they are partially removed during the bleaching of corn oil. We evaluated the chemical conversion of free phytosterols (FPs) during bleaching. FP degradation accelerated with increased time and temperature, following a first-order kinetic model. In the n-heptane system, air and activated clay promoted the chemical conversion of the FPs. Sterenes formation was analysed under different conditions using a zero-order kinetic model. The apparent activation energies revealed sterene formation decreasing in the following order: campesta-3,5-diene ≈ stigmasta-3,5,22-triene > stigmasta-3,5-diene. Isomers of the above were not detected, indicating that these sterenes were the only primary products of FPs. The desorption test indicated that the FP loss from corn oil was not only due to FPs being adsorbed the activated clay, but also FPs adsorbed at acidic activated sites being degraded. This study presents a vital scientific foundation for retaining FPs to develop healthier and more nutritious oils.

Blood phytosterols in relation to cardiovascular diseases and mediating effects of blood lipids and hematological traits: a Mendelian randomization analysis

BACKGROUND

Short-term clinical trials have shown the cholesterol-lowering potentials of phytosterols, but their impacts on cardiovascular disease (CVD) remain controversial. This study used the Mendelian randomization (MR) to investigate the relationships between genetic predisposition to blood sitosterol concentration and 11 CVD endpoints, along with the potential mediating effects of blood lipids and hematological traits.

METHODS

Random-effect inverse-variance weighted method was used as the main analysis of MR. Genetic instruments of sitosterol (seven SNPs, F = 253, and R² = 15.4 %) were derived from an Icelandic cohort. Summary-level data of the 11 CVDs were obtained from UK Biobank, FinnGen, and publicly available genome-wide association study results.

RESULTS

Genetically predicted one unit increment in log-transformed blood total sitosterol was significantly associated with a higher risk of coronary atherosclerosis (OR: 1.52; 95 % CI: 1.41, 1.65; n = 667,551), myocardial infarction (OR: 1.40; 95 % CI: 1.25, 1.56; n = 596,436), all coronary heart disease (OR: 1.33; 95 % CI: 1.22, 1.46; n = 766,053), intracerebral hemorrhage (OR: 1.68; 95 % CI: 1.24, 2.27; n = 659,181), heart failure (OR: 1.16; 95 % CI: 1.08, 1.25; n = 1,195,531), and aortic aneurysm (OR: 1.74; 95 % CI: 1.42, 2.13; n = 665,714). Suggestive associations were observed for an increased risk of ischemic stroke (OR: 1.06; 95 % CI: 1.01, 1.12; n = 2,021,995) and peripheral artery disease (OR: 1.20; 95 % CI: 1.05, 1.37; n = 660,791). Notably, blood non-high-density lipoprotein cholesterol (nonHDL-C) and apolipoprotein B mediated about 38-47 %, 46-60 %, and 43-58 % of the associations between sitosterol and coronary atherosclerosis, myocardial infarction, and coronary heart disease, respectively. However, the associations between sitosterol and CVDs were less likely to depend on hematological traits.

CONCLUSION

The study suggests that genetic predisposition to higher blood total sitosterol is linked to a greater risk of major CVDs. Moreover, blood nonHDL-C and apolipoprotein B might mediate a significant proportion of the associations between sitosterol and coronary diseases.

Heterologous expression of Chlorophytum borivilianum Squalene epoxidase in tobacco modulates stigmasterol production and alters vegetative and reproductive growth

KEYMESSAGE

CbSE overexpression increased stigmasterol levels and altered plant morphology. The genes upstream and downstream of CbSE were found to be upregulated, which confirms its regulatory role in the saponin biosynthetic pathway. Chlorophytum borivilianum is a high-value medicinal plant with many promising preclinical applications that include saponins as a major active ingredient. Squalene epoxidase (SE) is one of the major rate-limiting enzymes of the saponin biosynthetic pathway. Here, we functionally characterized C. borivilianum SE (CbSE) by over-expressing heterologously in Nicotiana tabacum. The heterologous expression of CbSE resulted in stunted pant growth with altered leaf and flower morphology. Next, RT-qPCR analysis of transgenic plants overexpressing CbSE revealed increased expression levels of Cycloartenol synthase (CAS), Beta amyrin synthase (βAS), and cytochrome P450 monooxygenase 51 (CYP51) (Cytochrome P450), which encode key enzymes for triterpenoid and phytosterol biosynthesis in C. borivilianum. Further, Methyl Jasmonate (MeJa) treatment upregulated Squalene synthase (SQS), SE, and Oxidosqualene cyclases (OSCs) to a significant level. GC-MS analysis of the leaf and hairy roots of the transformants showed an increased stigmasterol content (0.5-1.0 fold) compared to wild type (WT) plants. These results indicate that CbSE is a rate-limiting gene, which encodes an efficient enzyme responsible for phytosterol and triterpenoid production in C. borivilianum.

A Comprehensive Update on Phytochemistry, Analytical Aspects, Medicinal Attributes, Specifications and Stability of Stigmasterol

Phytosterols are bioactive substances naturally found in plant cell membranes, and their chemical structure is comparable to cholesterol found in mammalian cells. They are widely distributed in plant foods like olive oil, nuts, seeds, and legumes. Amongst the variety of phytosterols, stigmasterol is the vital compound found abundantly in plants. Numerous hormones, including estrogen, progesterone, corticoids and androgen, are synthesized by stigmasterol. Multiple in-vitro and in-vivo investigations have shown that stigmasterol has various biological effects, including antioxidant, anticancer, antidiabetic, respiratory diseases, and lipid-lowering effects. Experimental research on stigmasterol provides indisputable proof that this phytosterol has the potential to be employed in supplements used to treat the illnesses mentioned above. This substance has a high potential, making it a noteworthy medication in the future. Although several researchers have investigated this phytosterol to assess its prospective qualities, it has not yet attained therapeutic levels, necessitating additional clinical studies. This review offers a comprehensive update on stigmasterol, including chemical framework, biosynthesis, synthetic derivatives, extraction and isolation, analytical aspects, pharmacological profile, patent status, clinical trials, stability and specifications as per regulatory bodies.

The elucidation of structure-activity and structure-permeation relationships for the cutaneous delivery of phytosterols to attenuate psoriasiform inflammation

Phytosterols have been reported to exert anti-inflammatory activity. This study aimed to investigate the capacity of campesterol, β-sitosterol, and stigmasterol on the mitigation of psoriasiform inflammation. We also tried to establish structure-activity and structure-permeation relationships for these plant sterols. To support this study, we first approached the in silico data of the physicochemical properties and the molecular docking of phytosterols with stratum corneum (SC) lipids. The anti-inflammatory activity of the phytosterols was explored in the activated keratinocytes and macrophages. Using the activated keratinocyte model, a significant inhibition of IL-6 and CXCL8 overexpression by phytosterols was detected. A comparable inhibition level was found for the three phytosterols tested. The macrophage-based study showed that the anti-IL-6 and anti-CXCL8 activities of campesterol were greater than those of the other compounds, which indicated that a phytosterol structure without a double bond on C₂₂ and with methyl moiety on C₂₄ was more effective. The conditioned medium of phytosterol-treated macrophages decreased STAT3 phosphorylation in the keratinocytes, suggesting the inhibition of keratinocyte hyperproliferation. β-sitosterol was the penetrant with the highest pig skin absorption (0.33 nmol/mg), followed by campesterol (0.21 nmol/mg) and stigmasterol (0.16 nmol/mg). The therapeutic index (TI) is a parameter measured by multiplying the cytokine/chemokine suppression percentage with skin absorption for anticipating the anti-inflammatory activity after topical delivery. β-sitosterol is a potential candidate for treating psoriatic inflammation due to having the greatest TI value. In this study, β-sitosterol attenuated epidermal hyperplasia and immune cell infiltration in the psoriasis-like mouse model. The psoriasiform epidermis thickness could be reduced from 92.4 to 63.8 μm by the topical use of β-sitosterol, with a downregulation of IL-6, TNF-α, and CXCL1. The skin tolerance study manifested that the reference drug betamethasone but not β-sitosterol could generate barrier dysfunction. β-sitosterol possessed anti-inflammatory activity and facile skin transport, showing the potential for development as an anti-psoriatic agent.

Improving the production of 9α-hydroxy-4-androstene-3,17-dione from phytosterols by 3-ketosteroid-Δ1-dehydrogenase deletions and multiple genetic modifications in Mycobacterium fortuitum

BACKGROUND

9α-hydroxyandrost-4-ene-3,17-dione (9-OHAD) is a significant intermediate for the synthesis of glucocorticoid drugs. However, in the process of phytosterol biotransformation to manufacture 9-OHAD, product degradation, and by-products restrict 9-OHAD output. In this study, to construct a stable and high-yield 9-OHAD producer, we investigated a combined strategy of blocking Δ¹‑dehydrogenation and regulating metabolic flux.

RESULTS

Five 3-Ketosteroid-Δ¹-dehydrogenases (KstD) were identified in Mycobacterium fortuitum ATCC 35855. KstD2 showed the highest catalytic activity on 3-ketosteroids, followed by KstD3, KstD1, KstD4, and KstD5, respectively. In particular, KstD2 had a much higher catalytic activity for C9 hydroxylated steroids than for C9 non-hydroxylated steroids, whereas KstD3 showed the opposite characteristics. The deletion of kstDs indicated that KstD2 and KstD3 were the main causes of 9-OHAD degradation. Compared with the wild type M. fortuitum ATCC 35855, MFΔkstD, the five kstDs deficient strain, realized stable accumulation of 9-OHAD, and its yield increased by 42.57%. The knockout of opccr or the overexpression of hsd4A alone could not reduce the metabolic flux of the C22 pathway, while the overexpression of hsd4A based on the knockout of opccr in MFΔkstD could remarkably reduce the contents of 9,21 ‑dihydroxy‑20‑methyl‑pregna‑4‑en‑3‑one (9-OHHP) by-products. The inactivation of FadE28-29 leads to a large accumulation of incomplete side-chain degradation products. Therefore, hsd4A and fadE28-29 were co-expressed in MFΔkstDΔopccr successfully eliminating the two by-products. Compared with MFΔkstD, the purity of 9-OHAD improved from 80.24 to 90.14%. Ultimately, 9‑OHAD production reached 12.21 g/L (83.74% molar yield) and the productivity of 9-OHAD was 0.0927 g/L/h from 20 g/L phytosterol.

CONCLUSIONS

KstD2 and KstD3 are the main dehydrogenases that lead to 9-OHAD degradation. Hsd4A and Opccr are key enzymes regulating the metabolic flux of the C19- and C22-pathways. Overexpression of fadE28-29 can reduce the accumulation of incomplete degradation products of the side chains. According to the above findings, the MF-FA5020 transformant was successfully constructed to rapidly and stably accumulate 9-OHAD from phytosterols. These results contribute to the understanding of the diversity and complexity of steroid catabolism regulation in actinobacteria and provide a theoretical basis for further optimizing industrial microbial catalysts.

Solubilization of free β-sitosterol in milk sphingomyelin and polar lipid vesicles as carriers: Structural characterization of the membranes and sphingosome morphology

High consumption of plant sterols reduces the risk of cardiovascular diseases in humans and provides health benefits. Increasing the amount of plant sterols in the diet is therefore necessary to reach the recommended daily dietary intake. However, food supplementation with free plant sterols is challenging because of their low solubility in fats and water. The objectives of this study were to investigate the capacity of milk-sphingomyelin (milk-SM) and milk polar lipids to solubilise β-sitosterol molecules in bilayer membranes organised as vesicles called sphingosomes. The thermal and structural properties of milk-SM containing bilayers composed of various amounts of β-sitosterol were examined by differential scanning calorimetry (DSC) and temperature-controlled X-ray diffraction (XRD), the molecular interactions were studied using the Langmuir film technique, the morphologies of sphingosomes and β-sitosterol crystals were observed by microscopy. We showed that the milk-SM bilayers devoid of β-sitosterol exhibited a gel to fluid L_α phase transition for T_m = 34.5 °C and formed facetted spherical sphingosomes below T_m. The solubilisation of β-sitosterol within milk-SM bilayers induced a liquid-ordered L_o phaseabove 25 %mol (1.7 %wt) β-sitosterol and a softening of the membranes leading to the formation of elongated sphingosomes. Attractive molecular interactions revealed a condensing effect of β-sitosterol on milk-SM Langmuir monolayers. Above 40 %mol (25.7 %wt) β-sitosterol, partitioning occured with the formation of β-sitosterol microcrystals in the aqueous phase. Similar results were obtained with the solubilization of β-sitosterol within milk polar lipid vesicles. For the first time, this study highlighted the efficient solubilization of free β-sitosterol within milk-SM based vesicles, which opens new market opportunities for the formulation of functional foods enriched in non-crystalline free plant sterols.

Age-related reference intervals for serum phytosterols in children by gas chromatography-mass spectrometry and its application in diagnosing sitosterolemia

BACKGROUND AND AIMS

Serum phytosterol profiles are essential for the diagnosis and management of sitosterolemia. However, pediatric reference interval (RI) studies are scarce and various mass spectrometry (MS) approaches for phytosterol analysis still face multiple limitations. Therefore, an optimized gas chromatography (GC)-MS assay and age-related RIs in children are both required.

MATERIALS AND METHODS

Cholesterol and phytosterols (sitosterol, campesterol, cholestanol, stigmasterol, and sitostanol) were simultaneously determined by optimized GC-MS and performance was verified by the lower limit of quantification (LLOQ), linearity, precision, recovery, matrix effects, and method comparison. Healthy children (247 males and 263 females) were recruited, sex and age dependence were assessed using quantile regression (2.5th percentile and 97.5th percentile), and RIs were established according to Clinical and Laboratory Standards Association guideline C28-A3. These RIs were validated in 19 patients with sitosterolemia and 23 patients with hypercholesterolemia.

RESULTS

The optimized method shortened the sample processing time by approximately 60 min. Among the five phytosterols, all precision, recoveries (ranging from 89.97% to 104.94%), and relative matrix effects (%CV: ranging from 0.08% to 13.88%) met the specifications. GC-MS showed good agreement with lower cholesterol concentrations compared to conventional enzymatic methods. No significant differences between males and females were observed for all phytosterols, but age dependency was found and age-related RIs were established accordingly. Five phytosterols were significantly higher than RIs in patients with sitosterolemia.

CONCLUSION

We established age-related RIs for five phytosterols in children based on an optimized GC-MS assay, providing a screening tool for the diagnosis of sitosterolemia in children.

Comparison of the metabolomic and proteomic profiles associated with triterpene and phytosterol accumulation between wild and cultivated ginseng

Wild ginseng is thought to be superior in its medicinal quality to cultivated ginseng, potentially owing to the differences in active components. This study was designed accordingly to assess the differences in secondary metabolite components and their synthesis in wild and cultivated ginseng by using quantitative proteomics combined with secondary metabolomics approaches. A total of 72 secondary metabolites were found to be differentially abundant, of which dominant abundant in wild ginseng primarily included triterpenoid saponins (ginsenosides) and phytosterols. Ginsenoside diversity was increased in wild ginseng, particularly with respect to rare ginsenosides. Ginsenoside Rk1, F1, Rg5, Rh1, PPT, Rh2, and CK enriched in wild ginseng were validated by HPLC. In addition to ginsenosides, stigmasterol and β-sitosterol were accumulated in wild ginseng. 102 differentially expressed proteins between wild and cultivated ginseng were identified using iTRAQ labeling technique. Among them, 25 were related to secondary metabolism, mainly involved in sesquiterpene and triterpene biosynthesis, which was consistent with metabolomics results. Consistently, the activity levels of HMGR, FDPS, SS, SE, DS, CYP450, GT and CAS, which are key enzymes related to ginsenoside and phytosterol biosynthesis, were confirmed to be elevated in wild ginseng.The biosynthesis of ginsenosides and phytosterols in wild ginseng is higher than that in cultivated ginseng, which may be related to natural growth without artificial domestication. To some extent, this study explained the accumulation of pharmacodynamic components and overall quality of ginseng, which could provide reference for the germplasm improvement and planting of ginseng.

Current Trends and Perspectives in Microbial Bioconversions of Steroids

The microbiological transformation of sterols is currently the technological basis for the industrial production of valuable steroid precursors, the so-called synthons, from which a wide range of steroid and indane isoprenoids are obtained by combined chemical and enzymatic routes. These compounds include value-added corticoids, neurosteroids, sex hormones, bile acids, and other terpenoid lipids required by the medicine, pharmaceutical, food, veterinary, and agricultural industries.Progress in understanding the molecular mechanisms of microbial degradation of steroids, and the development and implementation of genetic technologies, opened a new era in steroid biotechnology. Metabolic engineering of microbial producers makes it possible not only to improve the biocatalytic properties of industrial strains by enhancing their target activity and/or suppressing undesirable activities in order to avoid the formation of by-products or degradation of the steroid core, but also to redirect metabolic fluxes in cells towards accumulation of new metabolites that may be useful for practical applications. Along with whole-cell catalysis, the interest of researchers is growing in enzymatic methods that make it possible to carry out selective structural modifications of steroids, such as the introduction of double bonds, the oxidation of steroidal alcohols, or the reduction of steroid carbonyl groups. A promising area of research is strain engineering based on the heterologous expression of foreign steroidogenesis systems (bacterial, fungal, or mammalian) that ensure selective formation of demanded hydroxylated steroids.Here, current trends and progress in microbial steroid biotechnology over the past few years are briefly reviewed, with a particular focus on the application of metabolic engineering and synthetic biology techniques to improve existing and create new whole-cell microbial biocatalysts.

Obtaining of 24-Norchol-4-ene-3,22-dione from Phytosterol with Mutants of Mycolicibacterium neoaurum

Engineered mutants of Mycolicibacterium spp. are known producers of valuable steroid synthons with C19 or C22 skeleton. Here we describe a method for site-directed mutagenesis of Mycolicibacterium neoaurum strains, bioconversion from phytosterol, and selective purification of C23 steroid 24-norchol-4-ene-3,22-dione (24-NCED) and C22 steroid 20-hydroxymethylpregn-4-ene-3-one (20-HMP). The yields of crystalline products with 95% purity by the method here described are 2.74 ± 0.085 g for 24-NCED and 1.42 ± 0.085 g for 20-HMP from 10 g/L phytosterol. 20-HMP is recognized as the key precursor in chemical syntheses of pharmaceutical corticosteroids and 24-NCED is a promising synthon for the synthesis of valuable steroids and own potent biological activity.

Mutants in Miniaturized and High-Throughput Format to Characterize Their Growth, Phytosterol Conversion Ability, and Resistance to the Steroid Products

This chapter describes methods for cultivation and characterization of the growth of Mycolicibacterium spp. mutants in a microbioreactor system in the presence of steroids and/or phytosterols followed by high-throughput mass spectrometry analysis to describe their ability to convert phytosterols into the target steroid androstenedione (AD). We focus on Mycolicibacterium neoaurum NRRL B-3805 ΔkstD which can convert phytosterol into androstenedione (AD) as one of its major steroid products, and mutants thereof with increased tolerance towards this end-product. By using BioLector 48-well plates with optodes at the bottom of each well, bacterial growth can be monitored online despite the turbidity of the growth medium resulting from non-dissolved phytosterol and steroid particles. To cope with the large number of samples that accumulate during growth experiments in microbioreactors and similar formats (e.g., microtiter plates), protocols for extraction and subsequent RapidFire-MS analysis are presented. This reduces the analysis time per sample to 10 s from 10 min required for regular LC-MS analysis.

A Case of Peripheral Precocious Puberty May Be Caused by a Diet Containing Phytosterols in a 20-Month-Old Boy

INTRODUCTION

Precocious puberty in boys generally remains an etiology. In addition to the causes of endogenous hormone changes, endocrine-disrupting chemicals of exogenous substances may interfere with children's pubertal development.

CASE PRESENTATION

A 20-month-old boy presented with peripheral precocious puberty may be due to a phytosterol-containing diet. The patient came to see a doctor because of acne, hairiness, increased penis size, and coarse voice. Genital examination revealed a Tanner stage of 2 for pubic hair and a stretched penile length of 5 cm, which disagreed with the prepubertal testicular volume (2 mL bilaterally). At the same time, he was found to have pigmentation on both nipples and areola. The concentrations of estradiol and testosterone increased significantly. Since the age of 6 months, the patient had taken food added with a large amount of chicken essence seasoning (a flavoring in Chinese cooking), with an average of 15 g of this seasoning a day. A kind of phytosterol (C29H48O) was detected in chicken essence seasoning by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS). After avoidance of the chicken essence seasoning, the patient's sex hormone levels decreased, all clinical symptoms returned to normal, and no further development of secondary sexual characteristics was detected.

CONCLUSION

This phytosterol-containing diet may be responsible for the sexual development of this patient. However, the mechanism of how phytosterols affect the process of development in children needs to be further explored.

Bioproduction of testosterone from phytosterol by Mycolicibacterium neoaurum strains: "one-pot", two modes

The main male hormone, testosterone is obtained from cheap and readily available phytosterol using the strains of Mycolicibacterium neoaurum VKM Ac-1815D, or Ac-1816D. During the first "oxidative" stage, phytosterol (5-10 g/L) was aerobically converted by Ac-1815D, or Ac-1816D to form 17-ketoandrostanes: androstenedione, or androstadienedione, respectively. At the same bioreactor, the 17-ketoandrostanes were further transformed to testosterone due to the presence of 17β-hydroxysteroid dehydrogenase activity in the strains ("reductive" mode). The conditions favorable for "oxidative" and "reductive" stages have been revealed to increase the final testosterone yield. Glucose supplement and microaerophilic conditions during the "reductive" mode ensured increased testosterone production by mycolicibacteria cells. Both strains effectively produced testosterone from phytosterol, but highest ever reported testosterone yield was achieved using M. neoaurum VKM Ac-1815D: 4.59 g/l testosterone was reached from 10 g/l phytosterol thus corresponding to the molar yield of over 66%. The results contribute to the knowledge on phytosterol bioconversion by mycolicibacteria, and are of significance for one-pot testosterone bioproduction from phytosterol bypassing the intermediate isolation of the 17-ketoandrostanes.

Characterization and functional analysis of BmSR-B1 for phytosterol uptake

Insects cannot synthesize sterols, such as cholesterol, and require sterols in their diet. Phytophagous insects use dietary phytosterols as a source of cholesterol. Sterols are transported from the midgut by the insect lipoprotein, lipophorin (Lp), although mechanisms for uptake of phytosterols into tissues are unclear. This study characterizes Scavenger Receptor class B type1 (SR-B1) from Bombyx mori (BmSR-B1) as molecules related to phytosterol uptake. According to sterol quantification using LC-MS/MS analysis, the midgut and fat body were phytosterol-rich relative to cholesterol-rich brain and prothoracic glands. Gene expression analysis of Bmsr-b1 in silkworm tissues showed that the genes Bmsr-b1_2, 3, 4, 6, and 10 were expressed in the midgut and fat body. To characterize the function of BmSR-B1, 11 BmSR-B1 homologs expressed in Bombyx ovary-derived BmN cells and Drosophila melanogaster embryo-derived Schneider 2 (S2) cells were incubated with purified Lp. Our analysis showed that BmSR-B1_3 induced the accumulation of campesterol and BmSR-B1_4 induced the accumulation of β-sitosterol and campesterol in culture cells. BmSR-B1 incorporated specific phytosterols into insect cells by selective uptake across the cell membrane where BmSR-B1 was localized. In conclusion, our study demonstrated that one function of BmSR-B1 is the uptake of phytosterols into silkworm tissues.

Interfacial organization and phase behavior of mixed galactolipid-DPPC-phytosterol assemblies at the air-water interface and in hydrated mesophases

The structural behavior of model assemblies composed of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG), the two main galactolipids found in plants, was investigated at the air/water interface and in aqueous dispersion. To approach the composition of the natural photosynthetic membranes, tunable Langmuir model membrane of galactolipids (GL) were used, and were complexified to form either heterogenous binary or ternary assemblies of GL, phospholipids (PL), and phytosterols (pS). The impact of pS, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or both on the structural properties of GL membrane was studied. The nature of the interactions between the different molecules was investigated using biophysical characterizations (ellipsometry, tensiometry, atomic force microscopy). In addition, the phase behavior was determined by SAXS analysis on the model assemblies in aqueous dispersions. Results revealed the good interfacial stability of these specific plant membrane lipids. The morphology of the GL film was characteristic of a fluid phase, with an interfacial roughness induced by the intercalation of monogalactosyl and digalactosyl polar heads of MGDG and DGDG, respectively. A phase heterogeneity in the monolayer was induced by the addition of DPPC and/or pS, which resulted in the modification of galactolipid organization and headgroup interactions. These structural changes were confirmed by SAXS analysis, showing more favorable interactions between MGDG and DPPC than between DGDG and DPPC in aqueous dispersion. This phenomenon was exacerbated in the presence of pS.

GC/EI-MS method for the determination of phytosterols in vegetable oils

Sterols are a highly complex group of lipophilic compounds present in the unsaponifiable matter of virtually all living organisms. In this study, we developed a novel gas chromatography with mass spectrometry selected ion monitoring (GC/MS-SIM) method for the comprehensive analysis of sterols after saponification and silylation. A new referencing system was introduced by means of a series of saturated fatty acid pyrrolidides (FAPs) as internal standards. Linked with retention time locking (RTL), the resulting FAP retention indices (RI_FAP) of the sterols could be determined with high precision. The GC/MS-SIM method was based on the parallel measurement of 17 SIM ions in four time windows. This set included eight molecular ions and seven diagnostic fragment ions of silylated sterols as well as two abundant ions of FAPs. Altogether, twenty molecular ions of C₂₇- to C₃₁-sterols with 0-3 double bonds were included in the final method. Screening of four common vegetable oils (sunflower oil, hemp oil, rapeseed oil, and corn oil) enabled the detection of 30 different sterols and triterpenes most of which could be identified.

Salvinia auriculata: chemical profile and biological activity against Staphylococcus aureus isolated from bovine mastitis

The aquatic plant Salvinia auriculata has been shown to possess promising properties for the treatment of Staphylococcus aureus bovine mastitis. The disease affects cattle health and compromises dairy cattle productivity, resulting in reduced milk production and higher mortality rates. The aim of this study was to evaluate the antimicrobial activity, antibiofilm activity, and toxicity of S. auriculata root extracts using bovine mammary epithelial cells (MAC-T); determine the chemical composition of the most active extract; and develop an S. auriculata antiseptic solution for pre- and post-milking teat disinfection. Plants were collected during the four seasons of the year. The most active hexane extract was subjected to bioguided fractionation, which resulted in the isolation of six known compounds, stigmast-22-ene-3,6-dione, stigmasterol, friedelinol, β-sitosterol, octadecyl alcohol, and octadecanoic acid. The antimicrobial and antibiofilm activities of the most active extract and isolated compounds were determined against nine S. aureus strains isolated from cows with mastitis. The efficacy of the S. auriculata teat dip formulation was tested using an excised teat model (ex vivo), and promising results were obtained. The S. auriculata extract formulation proved to be as effective as commercial antimicrobials in reducing log counts in excised teats.

Preparation and characterization of phytosterol-loaded nanoparticles with sodium caseinate/dextran conjugates

Sodium caseinate (SC)/dextran conjugates were prepared via Maillard reaction under controlled dry-heating conditions. Moreover, the nanoparticles of phytosterols (PS) encapsulated by SC or SC/dextran were produced using the emulsion evaporation method. The encapsulation efficiency (78.81 ± 5.22%) of PS in SC/dextran nanoparticles was higher than that (73.5 ± 2.78%) in SC nanoparticles. Compared with the compact and dense structure of SC nanoparticles, SC/dextran nanoparticles existed as relatively loose aggregates. The result of differential scanning calorimetry demonstrated that the encapsulation of PS greatly decreased its crystallinity. The released rates of PS from SC and SC/dextran nanoparticles under acidic gastric conditions were 8.59% and 4.73%, respectively. After 7 h of intestinal digestion, the released rate (52.19%) of PS from SC/dextran nanoparticles was significantly higher than that from SC (32.67%) nanoparticles. Therefore, SC/dextran conjugates prepared by the Maillard reaction are more suitable to be used as wall material for the nano-encapsulation of PS.

Comparing the stability of retinol in liposomes with cholesterol, β-sitosterol, and stigmasterol

In this study, cholesterol (CH), β-sitosterol (SI), and stigmasterol (ST) were explored to improve the stability of retinol in the liposome bilayer. Retinol was incorporated into liposomes composed of soybean-derived L-α-phosphatidylcholine (PC) and 10% sterol (w/w), which were prepared as multilamellar vesicles. Under all conditions, the efficiency of retinol incorporation into liposomes was higher than 99%, and the average particle size of liposomes was similar to that of PC alone. Liposomes were stored at 4 and 25 °C, with and without light, respectively, for 10 days. It was found that during the storage, CH and SI were effective in stabilizing the retinol in liposomes. These results indicate that an appropriate phytosterol could improve the stability of retinol in liposomes.

Combining a liquid-liquid extraction with successive air assisted liquid-liquid microextraction for the analysis of phytosterols present in animal based butter and oil samples

In this study, an elevated temperature liquid-liquid extraction combined method with successive air-assisted liquid-liquid microextraction has been proposed for the extraction of four phytosterols in cow milk butter and animal oil samples prior to gas chromatography-flame ionization detector. The method is started by combining a few grams of the melted butter or oil samples with ethanol. The mixture is vortexed and placed into a water-bath adjusted at 50 ⁰C. After a few minutes, the mixture is allowed to cool at room temperature. In this step, the butter or oil is become stiff and ethanol is collected on top of the sample. The separated ethanol phase is collected and mixed with deionized water to obtain a homogenous solution. After that, a few microliters of ethyl methyl ammonium chloride: pivalic acid deep eutectic solvent is added into the solution and the mixture was pulled into a glass test tube and pushed back to the tube for five times. After centrifugation, whole of the collected phase at the bottom of tube was withdrawn and transferred into a microtube and contacted with sodium hydroxide solution. The mixture is withdrawn and released to the tube 2 times to remove the extracted fatty acids. The validation data verified that high enrichment factors (385-450) and extraction recoveries (77-90%), low limits of quantification (2.6-5.2 ng g^-1) and detection (0.73-1.5 ng g^-1), and satisfactory relative standard deviations (≤ 9.3%) can be obtained with this method. At last, the developed method was successfully used for the analysis of phytosterols in various butter and oil samples marketed in Tabriz, Iran.

Fatty Acid Profile and Squalene, Tocopherol, Carotenoid, Sterol Content of Seven Selected Consumed Legumes

Legume seeds (Fabaceae) of seven species Cyamopsis tetragonoloba (guar), Glycine max (soybean), Lablab purpureus (lablab-bean), Macrotyloma uniflorum (kulthi bean), Phaseolus vulgaris (common bean), Trigonella foenum-graecum (fenugreek) and Vigna unguiculata (cowpea) were studied. The oil yield ranged from 1.2 to 20.2% dw, in the lablab-bean and soybean, respectively. The polyunsaturated fatty acids (PUFA) constituted the largest part (46-78%) of total fatty acids in studied legumes. γ-Tocopherol was the predominant tocopherol (T) homologue (61-95%) in most of the tested legumes with the exception of fenugreek (α-T, 97%) and cowpea (γ-T and δ-T, nearly equal). The β-sitosterol was the main sterol (51-56%) in most legumes. While in cowpea, lablab-bean and kulthi bean the main sterols were β-sitosterol and Δ5-stigmasterol (28-37% and 14-42%, respectively). Squalene was detected only in kulthi bean and lablab-bean (58 and 284 mg/100 g oil). The total concentration of carotenoids, tocochromanols, and sterols in the studied legumes was 0.2-9.2, 12.4-276.0, and 350-8,542 mg/100 g oil, respectively. Based on the levels of minor lipophilic compounds of this study, C. tetragonoloba, T. foenum-graecum and G. max seem to have a better nutritional value compared to P. vulgaris, V. unguiculata, L. purpureus, and M. uniflorum.

Three phytosterols from sweet potato inhibit MCF7-xenograft-tumor growth through modulating gut microbiota homeostasis and SCFAs secretion

Researches demonstrated that gut microbiota are associated with breast cancer progression. This study aims to evaluate the anti-breast tumor effects of daucosterol linolenate (DLA), daucosterol linoleate (DL), and daucosterol palmitate (DP) from sweet potato in MCF-7 xenograft nude mice by determining the tumor growth, serum tumor markers, tumor-related proteins, and performing 16S rDNA sequencing. After treatment at 87.8 mg/kg/day for 29 days, DLA, DL and DP delayed tumor growth and decreased levels of tumor marker carcinoembryonic antigen (CEA), cancer antigen 125 (CA125) and cancer antigen 153 (CA153) in vivo. All treatments activated caspase 3, 9, PARP1 cleavage, down-regulated Ki67, VEGF, BCL-2, BCL-XL, up-regulated BAX expression, and inhibited PI3K/AKT/NF-κB activation in tumor tissues. Their anti-breast tumor effects were associated with the regulation on gut microbiota. The three treatments increased Bacteroidetes whereas decreased Firmicutes richness. They also modulated the diversity of gut microbiota at family and genus levels. Furthermore, DL treatment promoted butyric acid secretion, DP promoted acetic acid and butyric acid secretion in the colorectal and feces. Our findings indicate that DLA, DL, and DP inhibit tumor growth in MCF-7 xenograft nude mice by regulating the homeostasis of gut microbiota, producing SCFAs, and then disturbing the expression of cancer-related proteins. The present study suggests three phytosterols as gut microbiota regulator for breast cancer prevention.

Different genome-wide transcriptome responses of Nocardioides simplex VKM Ac-2033D to phytosterol and cortisone 21-acetate

BACKGROUND

Bacterial degradation/transformation of steroids is widely investigated to create biotechnologically relevant strains for industrial application. The strain of Nocardioides simplex VKM Ac-2033D is well known mainly for its superior 3-ketosteroid Δ1-dehydrogenase activity towards various 3-oxosteroids and other important reactions of sterol degradation. However, its biocatalytic capacities and the molecular fundamentals of its activity towards natural sterols and synthetic steroids were not fully understood. In this study, a comparative investigation of the genome-wide transcriptome profiling of the N. simplex VKM Ac-2033D grown on phytosterol, or in the presence of cortisone 21-acetate was performed with RNA-seq.

RESULTS

Although the gene patterns induced by phytosterol generally resemble the gene sets involved in phytosterol degradation pathways in mycolic acid rich actinobacteria such as Mycolicibacterium, Mycobacterium and Rhodococcus species, the differences in gene organization and previously unreported genes with high expression level were revealed. Transcription of the genes related to KstR- and KstR2-regulons was mainly enhanced in response to phytosterol, and the role in steroid catabolism is predicted for some dozens of the genes in N. simplex. New transcription factors binding motifs and new candidate transcription regulators of steroid catabolism were predicted in N. simplex. Unlike phytosterol, cortisone 21-acetate does not provide induction of the genes with predicted KstR and KstR2 sites. Superior 3-ketosteroid-Δ1-dehydrogenase activity of N. simplex VKM Ac-2033D is due to the kstDs redundancy in the genome, with the highest expression level of the gene KR76_27125 orthologous to kstD2, in response to cortisone 21-acetate. The substrate spectrum of N. simplex 3-ketosteroid-Δ1-dehydrogenase was expanded in this study with progesterone and its 17α-hydroxylated and 11α,17α-dihydroxylated derivatives, that effectively were 1(2)-dehydrogenated in vivo by the whole cells of the N. simplex VKM Ac-2033D.

CONCLUSION

The results contribute to the knowledge of biocatalytic features and diversity of steroid modification capabilities of actinobacteria, defining targets for further bioengineering manipulations with the purpose of expansion of their biotechnological applications.

Fabrication and structural properties of water-dispersible phytosterol using hot melt extrusion

Hot-melt extrusion (HME) technology was employed to improve water dispersibility of phytosterol (P) using glycerol (G), lecithin (L), and gum arabic (A) as emulsifiers and stabilizers. The structural properties and water dispersibility of HME products were investigated. In contrast to physical mixtures, better water dispersibility and storage stability were observed for HME products, especially P:L:G:A extrudate. These improvements may be mainly associated with decreased crystallinity of phytosterol due to the occurrence of co-crystallization of phytosterol with glycerol during HME process, as confirmed by DSC and XRD data. In addition, HME-induced lecithin-arabic gum reaction products effectively stabilize phytosterol microparticle in aqueous dispersion by providing a steric hindrance. These results suggest that HME could be an effectively and potentially solvent-free technique to produce water-dispersible phytosterol on a large scale.

Identification of bottlenecks in 4-androstene-3,17-dione/1,4-androstadiene-3,17-dione synthesis by Mycobacterium neoaurum JC-12 through comparative proteomics

Intermediates such as 4-androstene-3,17-dione (AD) and 1,4-androstadiene-3,17-dione (ADD) have extensive clinical applications in the production of steroid pharmaceuticals. The present study explores the effect of two factors in the production of these intermediates in Mycobacterium neoaurum JC-12: the precursor, phytosterol and a molecule that increases AD/ADD solubility, hydroxypropyl-β-cyclodextrin (HP-β-CD). Differentially expressed proteins were separated and identified using 2D gel electrophoresis (2-DE) and matrix assisted laser desorption/ionization time-of-flight/time-of-flight tandem mass spectrometry (MALDI-TOF/TOF-MS/MS). In total, 31 proteins were identified, and improved expression levels of ten proteins involved in metabolism was induced by phytosterol and/or HP-β-CD, which strengthened the stress resistance of the strain. In the presence of phytosterol and/or HP-β-CD, five proteins involved in the synthesis of AD/ADD, acetyl-CoA acetyltransferase (AAT), alcohol dehydrogenase (ADH), enoyl-CoA hydratase (EH) and short-chain dehydrogenase 1 and 2, increased their expression levels. Reverse transcription-quantitative PCR (RT-qPCR) was used to verify the 2-DE results and the transcriptional level of these five proteins. This analysis identified AAT, ADH, EH, and electron transfer flavoprotein subunit α/β as the possible bottlenecks for AD/ADD synthesis in M. neoaurum JC-12, which therefore are suggested as targets for strain modification.

Effect of phytosterol capsule supplementation associated with the National Cholesterol Education Program Step 2 diet on low-density lipoprotein in children and adolescents with dyslipidemia: A double-blind crossover trial

OBJECTIVE

To evaluate the effect of phytosterol capsule supplementation associated with the National Cholesterol Education Program (NCEP) Step 2 diet on LDL-C levels in children and adolescents with dyslipidemia.

METHODS

This is a randomized, double-blind, crossover trial conducted with children and adolescents (n = 31; mean ± SD, age 9.0 ± 2.22 years, BMI zscore 1.65 ± 1.47 kg/m²) with dyslipidemia. After a run-in period, the participants were randomly allocated to control or intervention groups. The intervention group received capsules containing 1.5 g/day of phytosterols, and the control group received capsules containing 2 g/day of sunflower oil for 8 weeks. Patients in both groups were instructed to follow the NCEP Step 2 diet during the study. The primary outcome was LDL-C and secondary outcomes were total cholesterol (TC), HDL-C, triglyceride, insulin, blood pressure, and anthropometric measures. Intention-to-treat analyses were performed using the proc mixed procedure in SAS.

RESULTS

The rate of change for LDL-C was not different between intervention and control groups (p=0.30). No significant reduction was also observed for TC (p=0.47), HDL-C (p=0.97), insulin (p=0.27), triglycerides (p=0.38), systolic blood pressure (p=0.11), and diastolic blood pressure (p=0.57) compared to control group. Although we observed a high adherence to the capsule intake (95.7% in phytosterol and 93.8% in the control group), the low adherence to the diet may have contributed to explaining the results.

CONCLUSION

Daily phytosterol capsules supplementation associated with the NCEP Step 2 diet did not reduce LDL-cholesterol concentrations in children and adolescents with dyslipidemia.

Effectiveness of Echium amoenum on premenstrual syndrome: a randomized, double-blind, controlled trial

Background

The present study aimed to evaluate the effect of Echium amoenum (EA) on the severity of premenstrual syndrome (PMS) in comparison with placebo.

Methods

The present study was a randomized double-blind controlled clinical trial. A checklist questionnaire was completed by 120, 18 to 35-year-old, college students. And then, 84 eligible women (20 to 35 years old) were enrolled in the trial; they were randomly assigned to two groups of intervention (EA) and control (placebo), with 42 participants in each group. Participants in the intervention group received 450 mg capsules of EA per day (three times a day) from the 21st day of their menstrual cycle until the 3rd day of their next cycle for two consecutive cycles. The severity of PMS was measured and ranked using the premenstrual symptoms screening tool (PSST). The generalized estimating equation was used to compare the total score of the severity of PMS between the two groups.

Results

Sixty-nine women with regular menstrual cycles suffering from PMS completed the study. The mean scores of the symptoms in the EA group were 35.3 and 16.1 (P ≤ 0.001) at baseline and after 2 months, respectively, while the mean scores of the symptoms in the placebo group were 31.0 and 28.3 (P = 0.09) at baseline and after 2 months, respectively. The evaluation of the first and the second follow-ups in the intervention group showed that, after being adjusted for age and body mass index (P ≤ 0.001), the mean scores of the premenstrual syndrome, using GEE analysis, have decreased to 6.2 and 11.6, respectively.

Conclusion

Based on the results, in comparison with the placebo group, EA was found to be more effective in improving the symptoms of PMS, and is highly recommended for treatment of this syndrome.

Trial registration

IRCT2015110822779N3; Registration date: 2015–11–27.

Obtusifoliol 14α-demethylase OsCYP51G1 is involved in phytosterol synthesis and affects pollen and seed development

As structural components of biological membranes, phytosterols are essential not only for a variety of cellular functions but are also precursors for brassinosteroid (BR) biosynthesis. Plant CYP51 is the oldest and most conserved obtusifoliol 14α-demethylase in eukaryotes and is an essential component of the sterol biosynthesis pathway. However, little is known about rice (Oryza sativa L.) CYP51G1. In this study, we showed that rice OsCYP51G1 shared high homology with obtusifoliol 14α-demethylase and OsCYP51G1 was strongly expressed in most of rice organs. Subcellular localization analysis indicated that OsCYP51G1 was localized to the endoplasmic reticulum. Knockdown and knockout of OsCYP51G1 resulted in delayed flowering, impaired membrane integrity, abnormal pollen, and reduced grain yield, whereas OsCYP51G1 overexpression led to increased grain yield. Knockdown of OsCYP51G1 also reduced the levels of end-products (sitosterol and stigmasterol) and increased those of upstream intermediates (24-methylene-cycloartenol and cycloeucalenol) of the OsCYP51G1-mediated sterol biosynthesis step. In contrast, overexpression of OsCYP51G1 increased the sitosterol and stigmasterol content and reduced that of cycloeucalenol. However, knockdown of OsCYP51G1 by RNAi did not elicit these BR deficiency-related phenotypes, such as dwarfism, erect leaves and small seeds, nor was the leaf lamina angle sensitive to brassinolide treatment. These results revealed that rice OsCYP15G1 encodes an obtusifoliol 14α-demethylase for the phytosterols biosynthesis and possible without affecting the biosynthesis of downstream BRs, which was different from its homolog, OsCYP51G3.

Effects of enzymatic free fatty acid reduction process on the composition and phytochemicals of rice bran oil

The effects of enzymatic free fatty acid reduction process (EFFARP) on the composition and phytochemicals of dewaxed and degummed rice bran oil (DDRBO) were investigated and compared with the effects observed using internal acyl acceptors. The acid value of DDRBO was effectively decreased from 16.99 mg KOH/g to approximately 0.36 mg KOH/g by EFFARP. EFFARP significantly decreased the moisture content and peroxide value of DDRBO and increased the induction period. The Sn-2 fatty acid comoposition of DDRBO after EFFARP was very reaching the total fatty acid composition. EFFARP significantly increased the triacylglycerol content compared to the control, while the oryzanol content was not obviously affected. The contents of free sterol, and total tocopherol and tocotrienol were increased slightly by EFFARP compared to the control. When conducted under vacuum with added nitrogen, EFFARP shows great application potential in the edible oil industry.

Effects of Phytosterols supplementation on blood glucose, glycosylated hemoglobin (HbA1c) and insulin levels in humans: a systematic review and meta-analysis of randomized controlled trials

Background

In the literature, there are still controversies regarding the effect of phytosterol(PS) supplementation on fasting blood sugar (FBS), insulin levels and glycosylated hemoglobin (HbA1c) in humans. We aimed to assess the impact of PS supplementation on FBS, HbA1c and insulin levels by conducting a systematic review and meta-analysis of the available randomized controlled trials (RCTs).

Methods

A comprehensive search was conducted to identify all RCTs published up to May 2019 in the following databases: PubMed-MEDLINE, Web of Science, Cochrane Library and Scopus. The mean difference with 95% confidence intervals (CIs) was pooled using a random-effects model (DerSimonian-Laird method).

Results

Twenty-six arms from 20 RCTs were included in the present meta-analysis. Our findings show that PS supplementation decreases insulin levels (mean difference [MD]: -6.426 μU/ml, 95% CI: -7.187, -5.665, P- value = 0.000). However, PS supplementation did not have significant effects on FBS and HbA1c levels. Following PS supplementation, significant changes in FBS (mean difference [MD]: -1.942 mg/dl, 95% CI: -3.637, -0.246, P- value = 0.025) and HbA1c (mean difference [MD]: -0.059%, 95% CI: -0.114, -0.004, P- value = 0.035) based on PS dosage (mg/d) were recorded.

Conclusions

In patients with a baseline BMI <25 kg/m², PS consumption significantly increased FBS levels. Patients who consumed 1-2 g/day of PS had a lower FBS and lower HbA1c levels.

Enhancing the bioconversion of phytosterols to steroidal intermediates by the deficiency of kasB in the cell wall synthesis of Mycobacterium neoaurum

Background

The bioconversion of phytosterols into high value-added steroidal intermediates, including the 9α-hydroxy-4-androstene-3,17-dione (9-OHAD) and 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC), is the cornerstone in steroid pharmaceutical industry. However, the low transportation efficiency of hydrophobic substrates into mycobacterial cells severely limits the transformation. In this study, a robust and stable modification of the cell wall in M. neoaurum strain strikingly enhanced the cell permeability for the high production of steroids.

Results

The deletion of the nonessential kasB, encoding a β-ketoacyl-acyl carrier protein synthase, led to a disturbed proportion of mycolic acids (MAs), which is one of the most important components in the cell wall of Mycobacterium neoaurum ATCC 25795. The determination of cell permeability displayed about two times improvement in the kasB-deficient strain than that of the wild type M. neoaurum. Thus, the deficiency of kasB in the 9-OHAD-producing strain resulted in a significant increase of 137.7% in the yield of 9α-hydroxy-4-androstene-3,17-dione (9-OHAD). Ultimately, the 9-OHAD productivity in an industrial used resting cell system was reached 0.1135 g/L/h (10.9 g/L 9-OHAD from 20 g/L phytosterol) and the conversion time was shortened by 33%. In addition, a similar self-enhancement effect (34.5%) was realized in the 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC) producing strain.

Conclusions

The modification of kasB resulted in a meaningful change in the cell wall mycolic acids. Deletion of the kasB gene remarkably improved the cell permeability, leading to a self-enhancement of the steroidal intermediate conversion. The results showed a high efficiency and feasibility of this construction strategy.

In-vitro bioaccessibility of spray dried refined kenaf (Hibiscus cannabinus) seed oil applied in coffee drink

This study aimed to investigate the effect of a coffee beverage matrix on the oil release percentage and bioaccessibility of bioactive compounds from microencapsulated refined kenaf seed oil (MRKSO) using an in vitro gastrointestinal digestion model. Refined kenaf seed oil was spray-dried with gum arabic, β-cyclodextrin, and sodium caseinate. Oil release percentage, total phenolic content, radical scavenging activity of DPPH and ABTS, tocopherol and tocotrienol contents, as well as phytosterol content, were measured in the oil released from digested MRKSO along with the coffee matrix and compared to the digested MRKSO without coffee matrix and undigested MRKSO. Refined kenaf seed oil showed a significantly higher oxidative stability index than crude, degummed, and neutralized oil samples. About 91.2 and 94.7% of the oils were released from the digested MRKSO without and with coffee matrix, respectively. Oil released from the digested MRKSO with coffee matrix showed an increase in the total phenolic content (200.5%), DPPH (172.7%), and ABTS (68.1%) values, tocopherol and tocotrienol contents (24.6%), as well as the phytosterol content (62.0%), compared to oil released from the digested MRKSO without coffee matrix. MRKSO was successfully incorporated in the coffee drink and can use as a partial replacement for coffee creamers or supplementation in coffee drinks.

Effects of phytosterols supplementation on blood pressure: A systematic review and meta-analysis

Several reports have indicated a positive effect of phytosterols on blood pressure (BP), nevertheless these findings have been controversial. Therefore, a systematic review and meta-analysis of randomized controlled trials (RCTs) was aimed to investigate the effects of phytosterol supplementation on BP. An online search was carried out in PubMed, Scopus, ISI Web of Science, Cochrane library and Google Scholar up to May 2019. Weighted Mean difference (WMD) with 95% confidence intervals (CIs) were calculated using a fixed-effects model. The present meta-analysis of 19 RCTs showed that supplementation with phytosterols can decrease both systolic BP (WMD: -1.55 mmHg, 95% CI: -2.67 to -0.42, p = 0.007) and diastolic BP (WMD: -0.84 mmHg, 95% CI: -1.60 to -0.08, p = 0.03). Dose-response analysis revealed that phytosterol intake change SBP significantly based on treatment dose in nonlinear fashion. Subgroup analysis based on duration showed a significant effect of phytosterol on SBP and DBP in subsets of <12 weeks. In addition, a significant effect of phytosterol was observed in dosage of ≥2000 mg for SBP and <2000 mg for DBP. Based on current findings supplementation with phytosterol may be a beneficial adjuvant therapy in hypertensive patients as well as a complementary preventive option in prehypertensive and normotensive individuals. However, this issue is still open and requires further investigation in future studies.

Use of saw palmetto (Serenoa repens) extract for benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a noncancerous growth of the prostate. BPH commonly occurs in elderly men. Lower urinary tract symptoms (LUTS) secondary to BPH (LUTS/BPH) have significant impacts on their health. Saw palmetto (Serenoa repens) extract (SPE) has been evaluated for its effectiveness in improvement of LUTS/BPH at preclinical and clinical levels. Potential mechanisms of actions include anti-androgenic, pro-apoptotic, and anti-inflammatory effects. However, SPE efficacy was inconsistent, at least partly due to a lack of a standardized SPE formula. A hexane extract (free fatty acids, > 80%) provided more consistent results. Free fatty acids (lauric acid) were effective in inhibition of 5α-reductase, and phytosterol (β-sitosterol) reduced prostatic inflammation. Multiple actions derived from different constituents may contribute to SPE efficacy. Evaluation of the clinical relevance of these bioactive components is required for standardization of SPE, thereby enabling consistent efficacy and recommendations for the use in the prevention and treatment of BPH.

Nitrate Metabolism Decreases the Steroidal Alcohol Byproduct Compared with Ammonium in Biotransformation of Phytosterol to Androstenedione by Mycobacterium neoaurum

In biotransformation of phytosterol to 4-androstene-3,17-dione (AD) by Mycobacterium, the steroidal alcohol (such as 22-hydroxy-23,24-bisnorchol-4-ene-3-one, HBC) was a main byproduct. To weaken the accumulation of this byproduct in sterol biotransformation, ammonium was substituted by nitrate as nitrogen resource. The nitrate was utilized by Mycobacterium and led to metabolic flux shift towards AD production. The ratio of AD/HBC increased maximally from 2.1 to 5.5 and AD production increased correspondently. In the meanwhile, the nitrate metabolism resulted in the decreased intracellular redox level (NADH/NAD⁺) maximally by 59.5% and a slight descent tendency with the increase of the nitrate concentrations. It indicated that the nitrate utilization effectively decreased the steroidal alcohol production by regulating intracellular redox level in sterol biotransformation. These results gave an insight into the mechanism of the steroidal alcohol formation in sterol biodegradation and provided a simple strategy to regulate the metabolic distribution.

A novel phytosterol isolated from Datura inoxia, RinoxiaB is a potential cure colon cancer agent by targeting BAX/Bcl2 pathway

Plant sterols have been widely used as chemotherapeutic agents for colorectal cancer for years together. In this study, a novel phytosterol was isolated and characterized from the leaf extract of a medicinal plant, Datura inoxia and was coined as RinoxiaB (RB). This phytosterol was observed to have antiproliferative activity against human colon adenocarcinoma cells, HCT 15. The cell viability assay revealed the IC₅₀ value of the RB as 4 µM. Moreover, RB treated cells showed prominent morphological changes dose dependently and progressively increased the number of dead cells. Additionally, results of the comet, flow cytometry, and cell cycle analysis revealed that the majority of cells were arrested in their S and G2/M phase by blocking the mitotic spindle formation. The western blot analysis (Bcl-2, BAX, Cytochrome C, Caspases 9 & 3) clearly indicated that RB has the ability to induce apoptosis by significantly upregulating (P < 0.05) Bcl-2 and causing mitochondrial damage leading to Cytochrome C release and activation of caspases, which subsequently results in downregulation of BAX expression in the cytosol. Furthermore, the expression of tumor suppressors (p53 and p21) and cell cycle regulatory proteins (Cyclins D1 & B1) suggested that RB inhibit cell proliferation. Thus, the present finding concludes that RB can offer possible apoptotic effects by targeting BAX/Bcl2 pathway in HCT 15 cells, thus alleviating colon cancer.

Stigmasterol stimulates transintestinal cholesterol excretion independent of liver X receptor activation in the small intestine

Despite advances in healthcare, cardiovascular disease (CVD) remains the leading cause of death in the United States. Elevated levels of plasma cholesterol are highly predictive of CVD and stroke and are the principal driver of atherosclerosis. Unfortunately, current cholesterol lowering agents, such as statins, are not known to reverse atherosclerotic disease once it has been established. In preclinical models, agonists of nuclear receptor, LXR, have been shown to reduce and reverse atherosclerosis. Phytosterols are bioactive non-cholesterol sterols that act as LXR agonists and regulate cholesterol metabolism and transport. We hypothesized that stigmasterol would act as an LXR agonist and alter intestinal cholesterol secretion to promote cholesterol elimination. Mice were fed a control diet, or a diet supplemented with stigmasterol (0.3% w/w) or T0901317 (0.015% w/w), a known LXR agonist. In this experiment we analyzed the sterol content of bile, intestinal perfusate, plasma, and feces. Additionally, the liver and small intestine were analyzed for relative levels of transcripts known to be regulated by LXR. We observed that T0901317 robustly promoted cholesterol elimination and acted as a strong LXR agonist. Stigmasterol promoted transintestinal cholesterol secretion through an LXR-independent pathway.

Biochemistry of blood platelet activation and the beneficial role of plant oils in cardiovascular diseases

The main function of blood platelets is to form hemostatic plugs and enable thrombosis. These properties, however, can be greatly influenced by dietary components which may inhibit certain steps of platelet activation, including platelet aggregation. Such inhibition can play a role in the prophylaxis and treatment of cardiovascular diseases associated with blood platelet hyperactivation. In fact, plant and fish oils have been identified and specifically used for this purpose. Numerous in vivo and in vitro experiments have explored the potential use of these oils to inhibit platelet activation as well as their role in reducing oxidative stress and blood pressure, and lowering triglyceride and cholesterol. This chapter presents and compares the anti-platelet effects of fish and plant oils and their constituents, especially fatty acids. Studies on healthy subjects and patients with various cardiovascular diseases are also examined. Findings indicate that both fish and plant oils contain protective components with anti-platelet activity having clearly defined mechanisms of action. Although both are excellent sources of omega fatty acids and vitamins, plant oils contain components with cardioprotective benefit in hypercholesterolemics, i.e., phytosterols. Plant oils may hence play a key role in strategies for preventing and treating cardiovascular diseases associated with platelet hyperactivation. Further studies are clearly needed to determine the precise dose of these components needed for effective prophylaxis and treatment.

The lipid-lowering effect of once-daily soya drink fortified with phytosterols in normocholesterolaemic Chinese: a double-blind randomized controlled trial

PURPOSE

Phytosterols reduce intestinal cholesterol absorption and help to lower LDL-cholesterol. Many Chinese adults are lactose-intolerant and cannot tolerate bovine milk enriched with phytosterol. Soya-milk is a common beverage in Asia and it has beneficial effects on general health. We therefore conducted a randomized double-blind controlled trial to assess the effectiveness of a phytosterols-enriched soya drink in lowering serum LDL-cholesterol level (primary outcome) and other cardiovascular parameters (secondary outcomes).

METHODS

One hundred and fifty-nine normocholesterolaemic participants (85 men and 74 women; aged 19-79) were randomized to daily intake of one serving of phytosterols-enriched soya drink (N = 82), equivalent to 2 g of phytosterol per day, or a matched soya drink without phytosterols (N = 77) for 3 weeks. Adverse events, withdrawal and compliance were documented.

RESULTS

Among the treatment group (N = 82), phytosterols-enriched soya drink significantly decreased LDL-cholesterol by 5.96% (SE 1.48, 95% CI - 8.91%, - 3.00%) with a median of 6.74% compared with baseline, resulting in a significant reduction of 4.70% (95% CI - 8.89%, - 0.51%; p = 0.028) with a median of 5.20% compared with placebo (N = 77). In contrast, there were no significant changes in other lipid parameters, blood glucose, blood pressure, body weight or waist circumference. Remarkably, 95% of the participants randomized to the fortified drink reported no adverse events at all.

CONCLUSIONS

Daily consumption of a phytosterols-enriched soya drink may be a simple and cost-neutral means of lowering LDL-cholesterol in individuals in China, with massive population and rising incidence of coronary heart disease (ClinicalTrials.gov identifier: NCT02881658; date of registration: 14 Aug 2016).