Sterol transport proteins in yeast: a review / 生物工程学报

Sterols are a class of cyclopentano-perhydrophenanthrene derivatives widely present in living organisms. Sterols are important components of cell membranes. In addition, they also have important physiological and pharmacological activities. With the development of synthetic biology and metabolic engineering technology, yeast cells are increasingly used for the heterologous synthesis of sterols in recent years. Nevertheless, since sterols are hydrophobic macromolecules, they tend to accumulate in the membrane fraction of yeast cells and consequently trigger cytotoxicity, which hampers the further improvement of sterols yield. Therefore, revealing the mechanism of sterol transport in yeast, especially understanding the working principle of sterol transporters, is vital for designing strategies to relieve the toxicity of sterol accumulation and increasing sterol yield in yeast cell factories. In yeast, sterols are mainly transported through protein-mediated non-vesicular transport mechanisms. This review summarizes five types of sterol transport-related proteins that have been reported in yeast, namely OSBP/ORPs family proteins, LAM family proteins, ABC transport family proteins, CAP superfamily proteins, and NPC-like sterol transport proteins. These transporters play important roles in intracellular sterol gradient distribution and homeostasis maintenance. In addition, we also review the current status of practical applications of sterol transport proteins in yeast cell factories.

Biosynthesis of steroidal intermediates using Mycobacteria: a review / 生物工程学报

Steroids are a class of medicines with important physiological and pharmacological effects. In pharmaceutical industry, steroidal intermediates are mainly prepared through Mycobacteria transformation, and then modified chemically or enzymatically into advanced steroidal compounds. Compared with the "diosgenin-dienolone" route, Mycobacteria transformation has the advantages of abundant raw materials, cost-effective, short reaction route, high yield and environmental friendliness. Based on genomics and metabolomics, the key enzymes in the phytosterol degradation pathway of Mycobacteria and their catalytic mechanisms are further revealed, which makes it possible for Mycobacteria to be used as chassis cells. This review summarizes the progress in the discovery of steroid-converting enzymes from different species, the modification of Mycobacteria genes and the overexpression of heterologous genes, and the optimization and modification of Mycobacteria as chassis cells.

Phytosterol supplementation in the treatment of dyslipidemia in children and adolescents: a systematic review / Suplementação de fitoesteróis no tratamento da dislipidemia em crianças e adolescentes: uma revisão sistemática

ABSTRACT Objective: To carry out a systematic review on the effects of phytosterol supplementation on the treatment of dyslipidemia in children and adolescents. Data sources: Review in the SciELO, Lilacs, Bireme, PubMed and Web of Science databases, with no time limit. Descriptors: phytosterols or plant sterols and dyslipidemias, hypercholesterolemia, cholesterol, children, adolescent, in English and Portuguese. The articles included were published in Portuguese, English or Spanish and evaluated the effect of phytosterol supplementation in pediatric patients with dyslipidemia. Documents that involved adults or animals, review papers, case studies and abstracts were excluded. Two authors performed independent extraction of articles. Of 113 abstracts, 19 were read in full and 12 were used in this manuscript. Data synthesis: Phytosterol supplementation to reduce cholesterol levels has been shown to be effective in reducing LDL-cholesterol levels by approximately 10%, with reductions above 10% in LDL-cholesterol levels observed after 8 to 12 weeks of intervention. Studies have not shown significant changes in HDL-cholesterol and triglyceride levels. Based on the absence of adverse effects, its use seems to be safe and of good tolerance in children and adolescents. Conclusions: Phytosterol supplementation seems to be of great therapeutic aid for the treatment of hypercholesterolemia in children and adolescents. Further studies assessing the long-term effect of phytosterol supplementation are necessary.

RESUMO Objetivo: Realizar uma revisão sistemática sobre os efeitos da suplementação de fitoesteróis no tratamento da dislipidemia em crianças e adolescentes. Fontes de dados: Revisão nos bancos SciELO, Lilacs, Bireme, Pubmed e Web of Science, sem limite de tempo. Descritores: phytosterols or plant sterols, dyslipidemias, hypercholesterolemia, cholesterol, children, adolescent, nas línguas inglesa e portuguesa. Os artigos incluídos foram publicados nos idiomas português, inglês ou espanhol e avaliaram o efeito da suplementação de fitoesteróis em pacientes pediátricos com dislipidemia. Estudos que envolviam adultos ou animais, trabalhos de revisão, estudos de caso e resumos foram excluídos. A extração independente de artigos foi realizada por dois autores. Do total de 113 resumos, 19 foram lidos na íntegra, e 12 utilizados neste manuscrito. Síntese de dados: A suplementação de fitoesteróis para a redução dos níveis de colesterol mostrou-se eficiente, de forma a promover a redução de aproximadamente 10% dos níveis de LDL-colesterol, sendo observadas reduções acima de 10% em 8 a 12 semanas de intervenção. Os estudos não mostraram alterações significantes nos níveis de HDL-colesterol e triglicérides. Com base na ausência de efeitos adversos, seu uso parece ser seguro e de boa tolerância em crianças e adolescentes. Conclusões: A suplementação com fitoesteróis parece ser de grande auxílio terapêutico para o tratamento da hipercolesterolemia em crianças e adolescentes. São necessários mais estudos que avaliem o efeito em longo prazo da suplementação de fitoesteróis.

Reinforcement of sterols production through directed storage and transportation in yeast: a review / 生物工程学报

Sterols, a class of cyclopentane poly-hydrophenanthrene derivatives, are the predominant membrane constituent of eukaryotes. These substances have a variety of biological activities and have been widely used in food and pharmaceutical industries. The presence of endogenous ergosterol biosynthetic pathway in Saccharomyces cerevisiae cells make it an ideal chassis for the de novo synthesis of sterol and its derivatives. Most recently, the rational modification of organelles provides a novel strategy for the directed transportation and storage of target products and the ultimate enhanced product synthesis. This review summarizes the phenotypic responses of S. cerevisiae cells upon different physiological stimulations and the underlying molecular mechanisms. Reinforcement of sterol production through directed storage, transportation, and excretion of sterols offers a novel strategy for breaking the limitation of de novo biosynthesis of sterols in yeast.

Isolamento do estigmasterol do extrato hexânico das folhas de Sphagneticola trilobata Pruski (Asteraceae) / Isolation of stigmaterol from hexanic extract of the leaves of Sphagneticola trilobata Pruski (Asteraceae)

O interesse de pesquisadores e da população geral é bastante evidente, e tem crescido bastante na atualidade, no uso de plantas medicinais. A espécie de interesse deste trabalho, a Sphagneticola trilobata Pruski é uma planta herbácea pertencente à família Asteraceae. Alguns relatos têm mostrado a presença de diversos constituintes químicos nesta planta, principalmente diterpenos. O presente trabalho realizou o estudo fitoquímico de uma fração do extrato hexânico, devido ao baixo rendimento da fração diclorometânica, através da utilização de diversos métodos cromatográficos, na qual isolouse o fitoesterol estigmasterol. Este composto foi confirmado por meio de dados espectroscópicos e de literaturas, e o isolamento de compostos desta classe de substâncias indicam uma nova vertente para o uso medicinal desta planta como um futuro hipocolesterolêmico. Para isto, estudos serão direcionados para o isolamento de fitoesteróis, com posterior realização de ensaios biológicos (AU)

The interest of researchers and the general population is quite evident, and has grown considerably today, in the use of medicinal plants. The species of interest in this work, Sphagneticola trilobata Pruski is a herbaceous plant, belonging to Asteraceae family. Some reports have shown the presence of several chemical constituents in this plant, mainly diterpenes. The present work carried out the phytochemical study of a fraction of the hexane extract, due to the low yield of the dichloromethane fraction, by several chromatographic methods, in which the phytosterol estigmasterol was isolated. This compound has been confirmed by means of spectroscopic and literature data, and the isolation of compounds of this class of substances indicates a new strand for the medicinal use of this plant as a hypocholesterolemic future. For this, studies will be directed to the isolation of phytosterols, with subsequent biological tests (AU)

Chemical constituents of Calotropis procera latex and ultrastructural effects on Haemonchus contortus / Constituintes químicos do látex de Calotropis procera e efeitos ultraestruturais em Haemonchus contortus

Abstract This study aimed to evaluate the anthelmintic and ultrastructural effects of Calotropis procera latex on Haemonchus contortus. C. procera latex was twice centrifuged at 10,000×g and dialyzed to obtain a fraction rich in proteins, named LP (latex protein), and at 3,000 rpm to obtain a fraction rich in secondary metabolites, named LNP (latex non-protein). Specimens of H. contortus exposed to LNP, LP and PBS in the Adult Worm Motility Test (AWMT) were submitted to scanning (SEM) and transmission (TEM) electron microscopy to verify changes in their ultrastructure. Phytochemical tests in the LNP indicated the presence of phenols, steroids, alkaloids and cardenolides. High-Performance Liquid Chromatography (HPLC) characterized the presence of the compounds gallic acid and quercetin in the LNP. The protein content in the LP was 43.1 ± 1.1 mg/mL and 7.7 ± 0.3 mg/mL in LNP. In AWMT, LNP and LP inhibited the motility of 100% of the nematodes, with LNP being more effective than LP and ivermectin more effective than both (p <0.05). Cuticle changes were observed by SEM and TEM in nematodes treated with LP and LNP. Calotropis procera latex has anthelmintic effects against H. contortus, causing damage to its cuticle and other alterations in its ultrastructure.

Resumo Este estudo objetivou avaliar os efeitos anti-helmínticos e ultraestruturais do látex de Calotropis procera sobre Haemonchus contortus. Látex de C. procera foi centrifugado duas vezes à a 10.000xg e dialisado para obter uma fração rica em proteínas, denominada proteínas do látex (LP). E centrifugado e centrifugado a 3.000 rpm, para obter uma fração rica em metabólitos secundários, denominada LNP (látex não proteico). Espécimes de H. contortus expostos à LNP, LP e PBS no Teste de Motilidade dos Nematoides Adultos (TMNA) foram submetidos a microscopia eletrônica de varredura (MEV) e de transmissão (MET), para verificar alterações em sua ultraestrutura. Testes fitoquímicos em LNP indicaram a presença de fenóis, esteroides, alcaloides e cardenolídeos. A presença dos compostos ácido gálico e quercetina em LNP foi caracterizada por Cromatografia Líquida de Alta Eficiência (CLAE). O conteúdo de proteínas em LP foi de 43,1 ± 1,1 mg/mL e de 7,7 ± 0,3 mg/mL em LNP. No TMNA, LNP e LP inibiram a motilidade de 100% dos nematoides, sendo LNP mais eficaz que LP, e a ivermectina mais eficaz que ambos (p <0,05). Alterações na cutícula de nematoides tratados com LP e LNP foram observadas por MEV e MET. O látex de C. procera apresenta efeito anti-helmíntico sobre H. contortus, causando danos à sua cutícula e outras alterações em sua ultraestrutura.

Phytosterols Content in Vegetable Oils of Brazil: Coconut, Safflower, Linseed and Evening Primrose

Abstract In the last years phytosterols, natural components of plants, have received more attention due to association of their consumption with reducing risk of cardiovascular diseases and cancer. There are several scientific studies about phytosterols in vegetable oils, but they are scarce in unconventional oils. The objective of this research was evaluating the content of phytosterols (β-sitosterol, stigmasterol and campesterol) in vegetable oils sold in São Paulo city, in Brazil. The analysis included cold alkaline saponification, derivatization with hexamethyldisilazane and trimethylchlorosilane reagents, and quantification by gas chromatography using flame ionization detection and internal standardization. The quality control parameters indicated that the method was suitable for analysis. Total sterols were between 272.3 mg kg-1 (coconut oil) to 6169.7 mg kg-1 (evening primrose oil). β-sitosterol was the component found in higher concentrations and evening primrose oil was the most representative in quantity of phytosterols.

Effect of systemic administration of phytosterol on lacrimal quality of dogs / Efeito da administração sistêmica de fitoesterol na qualidade lacrimal de cães

The tear lipid layer (oily outer layer) reduces evaporation and prevents tear overflow. In dogs, reductions in the lipid components of this layer (cholesterol, triglycerides and phospholipids) can cause eye serious diseases. In this way, the tear crystallization test analyzes the lacrimal quality, however, it is less used in veterinary. As phytosterol reduces blood cholesterol, the objective of this study was to investigate, through the tear crystallization test, whether the systemic administration of this drug influences the lacrimal quality of healthy dogs and, in addition, to verify differences in the interpretation of the ophthalmic test between different evaluators. Eight beagles, healthy, of both sexes, young and adults, without clinical ophthalmic signs apparent were selected. Basal lacrimal samples (D0) were collected from the right and left eye of all animals with glass capillary tube and arranged on a glass slide for scanning the images and subsequent microscopic analysis. Subsequently, all were medicated with the phytosterol (Collestra® 650 mg: 1 capsule, orally, every 12 hours, for 15 days). After seven (D7) and fifteen (D15) days of this systemic administration, the tear crystallization test in both eyes of all dogs was again performed for statistical comparison with the baseline results. The photographs of the slides were classified by four evaluators (AV1 and AV2 with professional experience in ophthalmology and AV3 and AV4 without previous professional experience in ophthalmology), following standards established by Rolando (1984). The results were statistically verified by analysis of simple variance (ANOVA One-Way). There was no statistical difference in the tear crystallization test between the established periods and in relation to the different ophthalmic test evaluators (p≤0.05). Although phytosterols reduce blood cholesterol levels, it was observed in the present study that these drugs when administered systemically did not interfere in the tear lipid layer and, consequently, in the lacrimal quality of healthy dogs, and may be prescribed as lipid-lowering agents for patients with ocular diseases, especially the lacrimal ones.

A camada lipídica lacrimal (camada externa oleosa) reduz a evaporação e previne o transbordamento lacrimal. Em cães, reduções nos componentes lipídicos desta camada (colesterol, triglicérides e fosfolipídios) podem causar doenças graves nos olhos. Desta forma, o teste de cristalização lacrimal analisa a qualidade lacrimal, no entanto, é menos utilizado em veterinária. Como o fitoesterol reduz o colesterol sanguíneo, o objetivo deste estudo foi investigar, através do teste de cristalização lacrimal, se a administração sistêmica deste fármaco influencia na qualidade lacrimal de cães hígidos e, além disso, verificar diferenças na interpretação do teste oftalmológico entre diferentes avaliadores. Oito beagles, saudáveis, de ambos os sexos, jovens e adultos, sem sinais oftalmológicos clínicos aparentes foram selecionados. Amostras lacrimais basais (D0) foram coletadas do olho direito e esquerdo de todos os animais, com tubo capilar de vidro e, dispostas em lâmina de vidro para escaneamento das imagens e posterior análise microscópica. Ato contínuo todos foram medicados com o fitoesterol (Collestra® 650 mg: 1 cápsula, por via oral, a cada 12 horas, durante 15 dias). Após sete (D7) e quinze (D15) dias desta administração sistêmica, o teste de cristalização lacrimal em ambos os olhos de todos os cães foi novamente realizado para comparação estatística com os resultados basais. As fotografias das lâminas foram classificadas por quatro avaliadores (AV1 e AV2 com experiência profissional em oftalmologia e AV3 e AV4 sem experiência profissional prévia em oftalmologia), seguindo padrões estabelecidos por Rolando (1984). Os resultados foram estatisticamente verificados pela análise de variância simples (ANOVA One-Way). Não houve diferença estatística no teste de cristalização lacrimal entre os períodos estabelecidos e em relação aos diferentes avaliadores de teste oftalmológico (p≤0,05). Embora os fitoesteróis reduzam os níveis de colesterol no sangue, observou-se no presente estudo que esses fármacos quando administrados sistemicamente não interferiram na camada lipídica da lágrima e, consequentemente, na qualidade lacrimal de cães hígidos, podendo ser prescritos como agentes hipolipemiantes para pacientes com doenças oculares, especialmente as lacrimais.

Efeito de suplemento dietético à base de fitosterol associado à Dieta Passo II do NCEP sobre o LDL em crianças e adolescentes dislipidêmicos: Ensaio clínico randomizado cruzado, duplo cego / Effect of phytosterol dietary supplement associated with NCEP step II diet on LDL in dyslipidemic children and adolescents: double-blind, cross-over trial

Apesar das evidências do efeito dos esteróis vegetais entre adultos dislipidêmicos , dados sobre o uso de cápsulas com fitosteróis em crianças são limitados. O presente estudo teve como objetivo avaliar o efeito de suplemento dietético à base de fitosterol associado à dieta Passo II no NCEP no LDL de crianças e adolescentes dislipidêmicos em um hospital universitário no Rio de Janeiro. Deste modo, foi realizado um ensaio clínico randomizado cruzado, duplo cego com uso de placebo durante vinte semanas utilizando como critério de inclusão valores de lipoproteína de baixa densidade (LDL) maoir que 110mg/dL. Cinquenta e três crianças com idade entre 7 e 14 anos foram recrutadas, das quais 40 eram elegíveis para participar do estudo, sendo submetidas ao período do run in durante quatro semanas onde receberam orientações para seguir as recomendações da dieta Passo II do NCEP. Ao final do run in trinta e uma crianças e adolescentes permaneceram com LDL superior a 110mg/dL e foram randomizados para participar do estudo. O grupo intervenção recebeu cápsulas contendo 1,5mg/dia de fitosteróis na forma livre e esterificada e o grupo controle recebeu cápsulas contendo 2g/dia de óleo de girassol durante o período de oito semanas. Os participantes foram submetidos ao período do wash out durante quatro semanas. Foram coletados bioquímicos incluindo glicose, colesterol total, LDL, lipoproteína de alta densidade (HDL), triglicerídeos e dados antropométricos nas semanas 0, 8, 12 e 20. Foi realizada análise por intenção de tratar através dos modelos generalizados lineares mistos, usando o software SAS. Ao final do run in 9 participantes reduziram o LDL à menos 110 mg/dL, representando 25% da amostra. Foi observado ainda a prevalência de obesidade em 66,7% dos participantes que reduziram o LDL no run in. Após oito semanas, os participantes do grupo intervenção reduziram o LDL em 6,5%, enquanto o grupo controle apresentou redução de 1,7%. O HDL aumentou em 15,2% no grupo intervenção e 0,1% no grupo controle. 35% dos participantes do grupo intervenção alcançaram os valores considerados desejáveis para o LDL. Contudo, nenhuma destas variações foi significativamente diferente entre os grupos. Apesar do estudo não observar diferença estatisticamente significativa nas reduções do LDL entre os grupos o uso de suplementos a base de fitosteróis por meio de cápsulas mostrou-se seguro no tratamento das dislipidemias na infância e adolescência. Nota-se ainda que a dieta Passo II do NCEP mostrou-se efetiva na redução do LDL nas crianças e adolescentes obesos, sendo este um resultado relevante para redução do risco cardiovascular. Os resultados apresentados no presente estudo reforçam a necessidade de novos estudos envolvendo suplementação de fitosterol por meio de cápsulas, para que estes possam ser comparados.

Even with the evidence of lipid-lowering effect of plant sterols among dyslipidemic adults, the use of capsules with phytosterols in children is limited. The objective of the present study was evaluate the effect of phytosterol-based dietary supplementation associated with the Step II diet NCEP, in LDL of dyslipidemic children and adolescents at university hospital in Rio de Janeiro. A randomized, double-blind, crossover clinical trial with placebo was realized for 20 weeks. Thirty-one children and adolescents between seven and fourteen years old participated in the study. The intervention group received capsules containing 1.5g / day of phytosterols in the free and esterified form and the control group received capsules containing 2g / day of sunflower oil during the eight-week period. The partitipants were submited to wash out during four weeks. Biochemical data were collected including glucose, total cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL) and triglycerides; anthropometric measures at weeks 0, 8, 12 and 20. Intention-to-treat analysis were performed, using the proc mixed procedure in SAS. In the end of run in 9 participats reduced LDL above 110mg/dL, representing 25% sample size. The prevalence of obesity was also observed in 66.7% of the participants who reduced LDL in the run-in. Intention-to-treat analysis were performed, using the proc mixed procedure in SAS. After eight weeks, participants in the intervention group reduced LDL by 6.48%, while the control group had a reduction of 1.68%. HDL increased by 15.2% in the intervention group and 0.07% in the control group. 35% of participants in the intervention group achieved values considered desirable for LDL. However, none of these variations was significantly different between groups. Even the study did not achieve significantly statistic diference on reduction of LDL between the groups, the intake of phytosterol´s capsule showed safe on dislipidemic in child and youth treatment. It is also noted that the step II diet of the NCEP proved to be effective in reducing LDL in obese children and adolescents, which is a revealing result for reducing cardiovascular risk.The results presented in the present study reinforce the need for new studies involving supplementation of phytosterol with capsules, so that they can be compared.

Advances in research on hypolipidemic mechanism of phytosterols / 中国中药杂志

Hyperlipidemia,as one of the severe risk factors of cardiovascular disease,could easily trigger atherosclerosis,coronary heart disease,peripheral vascular disease,pancreatitis,etc.,and could also increase the incidence of type 2 diabetes and fatty liver disease. Improving dyslipidemia could slow down the progression of atherosclerosis and reduce the risk of coronary heart disease. This is of great importance for prevention and treatment of cardiovascular disease. Phytosterols are natural active ingredients in plants. Many researches have shown that phytosterols have significant lipid-lowering activity,which could effectively lower blood cholesterol and triglyceride levels. Foods containing phytosterols have been widely used as therapeutic diets for improving dyslipidemia. In the early years,it was believed that the lipid-lowering effect of phytosterols was achieved by competitively inhibiting the absorption of dietary cholesterol in the intestine since phytosterols had similar chemical structures with cholesterol. In further researches in recent years,more progress has been made in the lipid-lowering mechanisms of phytosterols. In this paper,PubMed and Web of Science were used to review the cholesterol-lowering and triglyceride-lowering mechanisms of phytosterols according to the available data published,so as to use phytosterols more rationally in clinical application to improve hyperlipidemia and other induced diseases.

New steroidal alkaloid and furostanol glycosides isolated from Solanum lyratum with cytotoxicity / 中国天然药物

Two previously undescribed steroidal compounds, 16, 23-epoxy-22, 26-epimino-cholest-22(N), 23, 25(26)-trien-3β-ol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside (1) and 26-O-β-D-glucopyranosyl-(25R)-5α-furost-20(22)-en-3β, 26-diol (2), together with 7 known ones including 26-O-β-D-glucopyranosyl-(25R)-5, 20(22)-dien-furost-3β, 26-diol (3), (25R)-5-en-spirost-3β-ol-O-β-D-glucopyranosyl-(1→4)-[α-L-rhmanopyranosyl-(1→2)]-β-D-galactopyranoside (4), funkioside D (5), aspidistrin (6), tigogenin-3-O-β-D-lucotrioside (7), desglucolanatigonin II (8), and degalactotigonin (9), were isolated from Solanum lyratum Thunb. Their cytotoxic activities were tested in two cancer cell lines by MTT method. One of the steroidal glycosides (6) showed significant cytotoxic activity against gastric cancer SGC7901 and liver cancer BEL-7402 cells.

New steroidal alkaloid and furostanol glycosides isolated from Solanum lyratum with cytotoxicity / 中国天然药物

Two previously undescribed steroidal compounds, 16, 23-epoxy-22, 26-epimino-cholest-22(N), 23, 25(26)-trien-3β-ol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside (1) and 26-O-β-D-glucopyranosyl-(25R)-5α-furost-20(22)-en-3β, 26-diol (2), together with 7 known ones including 26-O-β-D-glucopyranosyl-(25R)-5, 20(22)-dien-furost-3β, 26-diol (3), (25R)-5-en-spirost-3β-ol-O-β-D-glucopyranosyl-(1→4)-[α-L-rhmanopyranosyl-(1→2)]-β-D-galactopyranoside (4), funkioside D (5), aspidistrin (6), tigogenin-3-O-β-D-lucotrioside (7), desglucolanatigonin II (8), and degalactotigonin (9), were isolated from Solanum lyratum Thunb. Their cytotoxic activities were tested in two cancer cell lines by MTT method. One of the steroidal glycosides (6) showed significant cytotoxic activity against gastric cancer SGC7901 and liver cancer BEL-7402 cells.

Phytosterols in the Treatment of Hypercholesterolemia and Prevention of Cardiovascular Diseases / Fitosteróis no Tratamento da Hipercolesterolemia e Prevenção de Doenças Cardiovasculares

Abstract Phytosterols are bioactive compounds found in foods of plant origin, which can be divided into plant sterols and plant stanols. Clinical studies consistently indicate that the intake of phytosterols (2 g/day) is associated with a significant reduction (8-10%) in levels of low-density lipoprotein cholesterol (LDL-cholesterol). Thus, several guidelines recommend the intake of 2 g/day of plant sterols and/or stanols in order to reduce LDL-cholesterol levels. As the typical western diet contains only about 300 mg/day of phytosterols, foods enriched with phytosterols are usually used to achieve the recommended intake. Although phytosterols decrease LDL-cholesterol levels, there is no evidence that they reduce the risk of cardiovascular diseases; on the contrary, some studies suggest an increased risk of atherosclerosis with increasing serum levels of phytosterols. This review aims to address the evidence available in the literature on the relationship between phytosterols and risk of cardiovascular disease.

Resumo Os fitosteróis são compostos bioativos encontrados em alimentos de origem vegetal e que podem ser divididos em esteróis vegetais e estanóis vegetais. Estudos clínicos indicam de forma consistente que a ingestão de fitosteróis (2 g/dia) está associada a uma redução significativa (8-10%) de níveis de colesterol da lipoproteína de baixa densidade (LDL-C). Desta forma, diversas diretrizes recomendam a ingestão de 2 g/dia de esteróis e/ou estanóis vegetais com o objetivo de reduzir os níveis de LDL-C. Como uma dieta ocidental típica contém apenas cerca de 300 mg/dia de fitosteróis, normalmente são utilizados alimentos enriquecidos com fitosteróis para alcançar a ingestão recomendada. Apesar dos fitosteróis reduzirem os níveis de LDL-C, não há evidências de que reduzam o risco de doenças cardiovasculares. Pelo contrário, alguns estudos sugerem que a elevação na concentração sérica de fitosteróis possa estar associada com aumento no risco de aterosclerose. Esta revisão tem como objetivo abordar as evidências disponíveis na literatura sobre a relação entre fitosteróis e risco de doenças cardiovasculares.

Combined bioactive approach over atherosclerosis risk biomarkers / Abordagem combinada de compostos bioativos sobre biomarcadores de risco para aterosclerose

Atherosclerosis, one major cause of morbidity and mortality worldwide, is a complex and multifactorial disease that involves three mainly conditions: chronic inflammation, dyslipidemia and oxidative stress. Although statins are the first-line therapy for LDL cholesterol (LDL-C) lowering, the efficacy of cardiovascular events prevention is limited to 30-40%. This residual risk brought attention to the need of new therapies and clinical targets beyond LDL-C, such as inflammation and oxidative stress. Importantly, suboptimal treatment and/or statin discontinuation due to adverse effects have also been a very challenging clinical problem. Complementary diet therapy can be an effective and safe approach to support pharmacological treatment, especially when drugs alone are insufficient to attenuate risk factors and/or the recommended dose is not well tolerated. The aim of this study was to evaluate the effects of three bioactive components, namely omega-3 fatty acids, plant sterols and polyphenols, on markers of dyslipidemia, inflammation and oxidative stress in patients treated with statins. A randomized, crossover clinical study was carried out, with the participation of 53 subjects. At each intervention period, study participants received a packaged for the functional or control treatment. Functional treatment consisted of fish oil (1.7 g of EPA+DHA/day), chocolate containing plant sterols (2.2 g/day) and green tea (two tea sachets/day). Control treatment consisted of soy oil softgels, regular chocolate and anise tea. After 6 weeks of intervention, functional treatment reduced plasma LDL-C (-13.7% ± 3.7, p=0.002) and C-reactive protein (-35.5% ± 5.9, p=0.027). Plasma triacylglycerol (-15.68% ± 5.94, p=0.02) and MDA (-40.98% ± 6.74, p=0.04) were reduced in subgroups of patients (n=23) with baseline values above the median (93 mg/dL and 2.23 umol/L, respectively). Analysis of lathosterol and campesterol in plasma suggested that intensity of LDL-C reduction was influenced by cholesterol absorption rate rather than its endogenous synthesis. After multivariate analysis, patients identified as "good responders" to supplementation (n=10) were recruited for a pilot protocol of statin dose reduction with complementary diet therapy. Responders received the functional treatment for 12 weeks: standard statin therapy was kept during the first 6 weeks and reduced by 50% from weeks 6 to 12. No difference was observed for plasma lipids and inflammation biomarkers, cholesterol efflux capacity or HDL particle number after statin dose reduction when compared to standard therapy. Although limited by the small sample size, our study demonstrates the potential for a new therapeutic approach combining lower statin dose and specific dietary compounds. This may be particularly helpful for the many patients with, and at risk for, CVD who cannot tolerate high-dose statin therapy

A aterosclerose, uma importante causa mundial de morbidade e mortalidade, é uma doença complexa e multifatorial que envolve três principais condições: inflamação crônica, dislipidemia e estresse oxidativo. Embora as estatinas sejam fármacos de primeira linha para redução de LDL colesterol (LDL-C), sua eficácia na prevenção de eventos cardiovasculares é limitadada a 30-40%. Este risco cardiovascular residual evidencia a necessidade de novas terapias e marcadores clínicos que vão além do LDL-C, como inflamação e estresse oxidativo. Não obstante, tratamento subótimo e/ou interrupção do uso de estatinas devido à ocorrencia de efeitos adversos também é um grave obstáculo na clínica médica. Neste contexto, a terapia dietética complementar representa uma abordagem efetiva e segura para o suporte do tratamento farmacológico, especialmente quando as drogas são insuficientes para atenuar fatores de risco e/ou quando a dose recomendada não é bem tolerada. O objetivo do presente estudo foi avaliar o efeito de três compostos bioativos - ácidos graxos ômega 3, fitosteróis e polifenóis - sobre marcadores de inflamação, lipemia e estresse oxidativo em indivíduos tradados com estatinas. Foi realizado um estudo clínico randomizado, de delineamento crossover, com a participação de 53 voluntários. A cada período de intervenção, os participantes receberam um tratamento funcional ou controle. O tratamento funcional foi composto por cápsulas de óleo de peixe (1.7 g/dia de EPA+DHA), chocolate contendo fitosteróis (2.2 g/dia) e chá verde (dois sachês/dia). O tratamento controle foi composto por cápsulas de óleo de soja, chocolate sem adição de fitosteróis e chá de anis. Após 6 semanas de intervenção, o tratamento funcional reduziu a concentração plasmática de LDL-C (-13.7% ± 3.7, p=0.002) e proteína C-reativa (-35.5% ± 5.9, p=0.027). Triglicerídeos (- 15.68% ± 5.94, p=0.02) e malondialdeído (-40.98% ± 6.74, p=0.04) foram reduzidas apenas em subgrupos de indivíduos que apresentavam valores basais acima da mediana (93 mg/dL e 2.23 umol/L, respectivamente). A análise de latosterol e campesterol no plasma sugeriu que a intensidade da redução de LDL-C não foi influenciada pela síntese endógena de colesterol, mas sim pela taxa de absorção. Após análise multivariada dos resultados, pacientes identificados como "good responders" à suplementação (n=10) foram recrutados para um estudo piloto de redução da dosagem da estatina, aliado à terapia dietética complementar. Estes pacientes receberam o tratamento funcional por 12 semanas: durante as 6 primeiras semanas mantevese a dosagem de estatina, que em seguida foi reduzida em 50% das semanas 6 a 12. Não foram observadas diferenças para os marcadores plasmáticos de lipídeos, inflamação, capacidade de efluxo de colesterol ou número de partículas de HDL após a redução da dose de estatina, quando comparada à terapia convencional. Embora limitado pelo reduzido número de pacientes, o estudo demonstra o potencial para uma nova abordagem terapêutica, combinando reduzida dose de estatina com específicos compostos bioativos. Esta pode ser uma importante alternativa para muitos pacientes em risco cardiovascular e que são intolerantes à terapia com altas doses de estatina.

Bitter gourd (Momordica charantia L. ) seed oil as a naturally rich source of bioactive compounds for nutraceutical purposes

Background: Characterization of food lipids has triggered the development of applications for the food and health industries. Thus, the lipid profiles of an increasing number of fruits and their seeds have been characterized and numerous bioactive components have been isolated. The bitter gourd seed oil has aroused great interest because it contains relevant amounts of conjugated fatty acid α-eleostearic acid (C18:3 9c11t13t), a positional and geometric isomer of α-linolenic acid. The aim of this paper was to evaluate the phytochemical composition and quality parameters of the seed oil of bitter gourd grown in Brazil. Methods: Bitter gourd was purchased from CEAGESP (Brazilian company of fresh food storages and warehouses). Seeds were lyophilized, and their oil was extracted using the Soxhlet and Folch extraction methods. The profiles of fatty acids and phytosterols were analyzed by gas chromatography, and the acidity and peroxide values were evaluated by methods of the American Oil Chemists' Society (AOCS). Results: The Soxhlet extraction (40 % w / w ) resulted in a higher yield of bitter gourd seed oil than the Folch extraction (16 % w / w). For both methods, α-eleostearic acid (56 and 58 %) was the major lipid in bitter gourd seed oil, followed by stearic acid (C18:0; 32 and 27 %). The oil displayed high content of phytosterols (886 mg/100 g), mainly ß-sitosterol, and low acidity and peroxide values. Conclusions: Bitter gourd seed oil from Brazil is an oil of good quality and its high contents of α-eleostearic acid and phytosterols with potential health-beneficial properties make it an attractive plant byproduct.

Fuentes naturales de fitoesteroles y factores de producción que lo modifican / Natural sources of phytosterols and production factors that modify them

Actualmente los fitoesteroles son adicionados a los alimentos industrializados, lo que aumenta su costo y por lo tanto limita su consumo. Este manuscrito tiene como objetivo identificar alimentos que son una fuente natural de fitoesteroles, así como también analizar cómo el ambiente y el manejo productivo modifican su contenido, relacionando estos aspectos con la salud. Los fitoesteroles son compuestos presentes en las plantas con propiedades hipocolesterolémicas, que pueden contribuir a prevenir las enfermedades cardiovasculares. La ingesta diaria estimada de fitoesteroles varía entre 160 y 500 mg/día, sin embargo su acción beneficiosa se logra con consumos de 1500 mg a 2400 mg diarios. Las semillas de oleaginosas y de cereales son las mayores fuentes naturales de fitoesteroles. El amaranto es considerado un pseudocereal y entre los cereales tiene la mayor concentración de fitoesteroles con 178 mg/100 g, valor 5 veces superior al de la harina de trigo. El ambiente modifica el contenido de fitoesteroles de los alimentos, la sequía y temperaturas altas duplican su contenido en las semillas; la fertilización nitrogenada y la fecha de siembra pueden provocar cambios, pero se requieren más estudios al respecto. La selección de genotipos con mayor contenido de fitoesteroles y el estudio de la interacción genotipo ambiente, permitirá la identificación de aquellos genotipos con adaptación local para este carácter. El manejo productivo podrá aumentar la oferta de alimentos naturales ricos en fitoesteroles, contribuyendo a una mayor oferta de alimentos protectores de la salud(AU)

Currently phytosterols are added to processed foods, which increase their cost and therefore limits its use. This manuscript aims to identify foods that are a natural source of phytosterols, as well as analyze how the environment and production management modify its content, linking these aspects with health. Phytosterols are compounds found in plants with hypocholesterolemic properties, which may help prevent cardiovascular diseases. The estimated daily intake of phytosterols varies between 160 and 500 mg/day, but its beneficial effect is achieved with 1,500 to 2,400 mg daily consumption. Oil and cereal seeds are the largest natural sources of phytosterols. Amaranth is considered a pseudocereal and among the cereals has the highest concentration of phytosterols with 178 mg/100 g, value 5 times higher than wheat flour. Environment modifies phytosterol content in food, drought and high temperatures can double their content in seeds; nitrogen fertilization and planting date can cause changes, but more studies are needed. The selection of genotypes with higher phytosterol content and studying the genotype x environment interaction, allow the identification of those genotypes with local adaptation for this character. The production management will increase the supply of natural foods rich in phytosterols, contributing to a greater supply of health protective foods(AU)

Phytosterols isolated from endophytic fungus Colletotrichum gloeosporioides (Melanconiaceae) / Fotoesteróis isolados do fungo endofítico Colletotrichum gloeosporioides (Melanconiaceae)

Endophytic fungi are fungi that colonize internal tissues of plants. There are few studies of compounds isolated from endophytic fungi of Amazon plants. Thus, the aim this study was the isolation and structural identification of sitosterol (1), stigmasterol (2), sitostenone (3), squalene (4), ergosterol (5) and ergosterol peroxide (6) from fungus Colletotrichum gloeosporioidesisolated as endophytic from Virola michelli, a typical Amazon plant, used in folk medicine against skin infection. Compounds were isolated by chromatography column on silica and identified by 1H and 13C NMR and MS. The presence of phytosterols in fungi is rare and this is the first report of the isolation of the phytosterols sitosterol, stigmasterol and sitostenone from the genus Colletotrichum.

Fungos endofíticos são fungos que colonizam os tecidos internos das plantas. Existem poucos estudos de compostos isolados de fungos endofíticos de plantas da Amazônia. Assim, o objetivo deste estudo foi o isolamento e identificação estrutural de sitosterol (1), estigmasterol (2), sitostenona (3), esqualeno (4), ergosterol (5) e peroxido de ergosterol (6) do fungo Colletotrichum gloeosporioidesisolado como endofítico de Virola michelli, uma planta típica da Amazônia, usada na medicina popular no combate a infecções de pele. Os compostos foram isolados por cromatografia em coluna de sílica e identificados por RMN 1H e 13C e EM. A presença de fitoesteróis em fungos é rara e este é o primeiro relato do isolamento dos fitoesteróides sitosterol, estigmasterol e sitostenona do gêreno Colletotrichum.

Sitosterolemia: a review and update of pathophysiology, clinical spectrum, diagnosis, and management

Sitosterolemia is an autosomal recessive disorder characterized by increased plant sterol levels, xanthomas, and accelerated atherosclerosis. Although it was originally reported in patients with normolipemic xanthomas, severe hypercholesterolemia have been reported in patients with sitosterolemia, especially in children. Sitosterolemia is caused by increased intestinal absorption and decreased biliary excretion of sterols resulting from biallelic mutations in either ABCG5 or ABCG8, which encode the sterol efflux transporter ABCG5 and ABCG8. Patients with sitosterolemia show extreme phenotypic heterogeneity, ranging from almost asymptomatic individuals to those with severe hypercholesterolemia leading to accelerated atherosclerosis and premature cardiac death. Hematologic manifestations include hemolytic anemia with stomatocytosis, macrothrombocytopenia, splenomegaly, and abnormal bleeding. The mainstay of therapy includes dietary restriction of both cholesterol and plant sterols and the sterol absorption inhibitor, ezetimibe. Foods rich in plant sterols include vegetable oils, wheat germs, nuts, seeds, avocado, shortening, margarine and chocolate. Hypercholesterolemia in patients with sitosterolemia is dramatically responsive to low cholesterol diet and bile acid sequestrants. Plant sterol assay should be performed in patients with normocholesterolemic xanthomas, hypercholesterolemia with unexpectedly good response to dietary modifications or to cholesterol absorption inhibitors, or hypercholesterolemia with poor response to statins, or those with unexplained hemolytic anemia and macrothrombocytopenia. Because prognosis can be improved by proper management, it is important to find these patients out and diagnose correctly. This review article aimed to summarize recent publications on sitosterolemia, and to suggest clinical indications for plant sterol assay.

Mineral, Nutritional, and Phytochemical Profile, Total Phenolic Content, and Radical Scavenging Activity of Philippine Bamboo "Bolo" Gigantochloa levis (Blanco) Merr. Leaves

The study is a pioneering effort to determine the mineral, nutritional, and phytochemical composition and phenolic content and to determine the free radical scavenging activity of Gigantochloa levis (Blanco) Merr, a native bamboo species (locally known as "bolo") in the Philippines. Proximate analysis showed that air-dried G. levis leaves contain 15.8% ash, 22.6% crude protein, 1.2% crude fat, 29.3% crude fiber, and 19.7% total sugar. Phytochemical tests indicated the presence of diterpenes, triterpenes, saponins, phenols, tannins, and flavonoids in both the ethanolic and aqueous leaf extracts, while phytosterols were only detected in the ethanolic extract. Folin-Ciocalteu assay determined the total phenolic content in gallic acid equivalents (GAE) to be 85.86 ± 3.71 and 32.32 ± 1.01 mg GAE/100 g dried sample for the ethanolic and aqueous extracts, respectively. The total phenolic content in quercetin equivalents (QE) was 74.44 ± 3.11 and 29.43 ± 0.85 mg QE/100g dried sample for the ethanolic and aqueous extracts, respectively. The radical scavenging activity of the different solvent fractions containing varying concentrations of the extract was determined using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. The ethyl acetate and 1-butanol fractions were found to have the highest radical scavenging activity. Mineral analysis via Energy Dispersive X-Ray Spectrometry (EDS) of the ash of G. levis leaves showed that Si is the major component, followed by K and Mg. These results point to the potential of G. levis leaves as a source of minerals and bioactive compounds with medicinal value.