Effects of passion fruit (Passiflora tenuifila Killip) intake on eutrophic and obese subjects: Lipidomic approach

Obesity and overweight result in metabolic changes that build up as risk factors for the development of the main non-communicable diseases. Among these alterations, dyslipidemia is an important risk factor for cardiovascular diseases (CDV) and is expressed in elevated plasma levels of triacylglycerols, cholesterol, and low-density-lipoprotein (LDL, VLDL) and decreased plasma levels of high-density lipoprotein (HDL). Passiflora tenuifila Killip is a native passion fruit species of the Brazilian Midwest region and is a good source of proanthocyanidins and dietary fibers. Proanthocyanidins are a class of phenolic compounds that are attributed with improving lipoprotein profile properties, translated as improved LDL/HDL ratio. Fibers are fermented by the gut microbiota and produce short-chain fatty acids (SCFA), also involved in the regulation of energetic metabolism.. A 30-consecutive-day-long intervention with lyophilized P. tenuifila flour was performed in eutrophic and obese subjects. Passion fruit ingestion increased fecal production of acetate, key SCFA in the modulation of lipid metabolism; reduced body fat percentage in all subjects; and reduced total cholesterol (TC) of subjects who presented basal CT > 130 mg/dL. After the intervention, plasma lipidomic analysis detected 44 statistically significant lipids, regardless of BMI. Considering the study population with altered TC, reduced levels of glycerophospholipids were observed, a lipid class studied for their involvement in CVD. The intake of P. tenuifila contributed to the improvement in cardiovascular risk markers and acts on lipid metabolism. These effects may be due to synergic action between the bioactive compounds in the fruit. Still, other studies are necessary to identify mechanisms related to the action of bioactives of P. tenuifila, which can be better directed by this lipidomic approach

A obesidade e o sobrepeso são preocupações resultam em alterações metabólicas que se acumulam como fatores de risco para o desenvolvimento a longo prazo das principais doenças crônicas não transmissíveis. Dentre essas alterações, a dislipidemia um importante fator de risco para doenças cardiovasculares (DCV), expressa em níveis plasmáticos elevados de triacilgliceróis, colesterol e das lipoproteínas de baixa densidade (VLDL, LDL), e níveis diminuídos da lipoproteína de alta densidade (HDL). Passiflora tenuifila Killip é uma espécie de maracujá nativa da região Centro-Oeste brasileira, e é uma boa fonte de proantocianidinas e fibras alimentares. As proantocianidinas são compostos fenólicos com reportados efeitos na melhora do perfil de lipoproteínas, traduzida como a relação LDL/HDL. As fibras são fermentadas pela microbiota intestinal e produzem ácidos graxos de cadeia curta (AGCC), metabólitos também envolvidos na regulação do metabolismo energético.. Assim, a lipidômica não-target é aplicada como ferramenta exploratória neste estudo: uma intervenção de 30 dias consecutivos de ingestão de P. tenuifila na forma de farinha liofilizada em indivíduos eutróficos e obesos. O consumo do maracujá promoveu aumento da produção fecal de acetato, AGCC importante na modulação do metabolismo lipídico; a redução do percentual de gordura corporal em todos os indivíduos; e redução do colesterol total (CT) para os indivíduos com CT > 130 mg/dL. A análise lipidômica do plasma detectou 44 lipídios estatisticamente relevantes, independentemente do IMC, após a intervenção. Considerando a população do estudo com CT alterado, foi observada uma redução de glicerofosfolipídios, classe de lipídios estudada pelo seu envolvimento em DCV. Assim, a ingestão de P. tenuifila contribui para a melhora nos marcadores de risco cardiovascular e atua no metabolismo lipídico. Estes efeitos podem ser decorrentes de sinergia entre os diversos compostos bioativos do fruto. Ainda, outros estudos são necessários para identificar mecanismos relacionados a ação dos bioativos da P. tenuifila e estes podem ser mais bem direcionados pela lipidômica

New chemical biopsy tool for spatially resolved profiling of human brain tissue in vivo.

It is extremely challenging to perform chemical analyses of the brain, particularly in humans, due to the restricted access to this organ. Imaging techniques are the primary approach used in clinical practice, but they only provide limited information about brain chemistry. Solid-phase microextraction (SPME) has been presented recently as a chemical biopsy tool for the study of animal brains. The current work demonstrates for the first time the use of SPME for the spatially resolved sampling of the human brain in vivo. Specially designed multi-probe sampling device was used to simultaneously extract metabolites from the white and grey matter of patients undergoing brain tumor biopsies. Samples were collected by inserting the probes along the planned trajectory of the biopsy needle prior to the procedure, which was followed by metabolomic and lipidomic analyses. The results revealed that studied brain structures were predominantly composed of lipids, while the concentration and diversity of detected metabolites was higher in white than in grey matter. Although the small number of participants in this research precluded conclusions of a biological nature, the results highlight the advantages of the proposed SPME approach, as well as disadvantages that should be addressed in future studies.

Comprehensive Evaluation of a Quantitative Shotgun Lipidomics Platform for Mammalian Sample Analysis on a High-Resolution Mass Spectrometer.

Shotgun lipidomics is a powerful tool that enables simultaneous and fast quantification of diverse lipid classes through mass spectrometry based analyses of directly infused crude lipid extracts. We present here a shotgun lipidomics platform established to quantify 38 lipid classes belonging to four lipid categories present in mammalian samples and show the fine-tuning and comprehensive evaluation of its experimental parameters and performance. We first determined for all the targeted lipid classes the collision energy levels optimal for the recording of their lipid class- and species-specific fragment ions and fine-tuned the energy levels applied in the platform. We then performed a series of titrations to define the boundaries of linear signal response for the targeted lipid classes, and demonstrated that the dynamic quantification range spanned more than 3 orders of magnitude and reached sub picomole levels for 35 lipid classes. The platform identified 273, 261, and 287 lipid species in brain, plasma, and cultured fibroblast samples, respectively, at the respective optimal working sample amounts. The platform properly quantified the majority of these identified lipid species, while lipid species measured to be below the limit of quantification were efficiently removed from the data sets by the use of statistical analyses of data reproducibility or a cutoff threshold. Finally, we demonstrated that a series of parameters of cell culture conditions influence lipidomics outcomes, including confluency, medium supplements, and use of transfection reagents. The present study provides a guideline for setting up and using a simple and efficient platform for quantitatively exploring the mammalian lipidome.

Carbon nanotube based dielectric spectroscopy of tumor secretion; electrochemical lipidomics for cancer diagnosis.

Cell free diagnosis of cancer is one of the crucial fields in new generation of medical technology. In this regard, cancer detection based on coastal fluids secreted from the tissues (named as secretome) has attracted a lot of attention. Lipids are important macromolecules could be found with much higher concentrations in secretome of cancer tissues vs. normal ones. On the other hand, lipids are the main dielectric components of the secretome with respect to proteins and ions. Here for the first time we introduced an electrochemical lipidomics based on electrical impedance spectroscopy (EIS) of the secretomes to detect the cancerous samples due to the lipidic content of their secretions. The EIS sensor was fabricated by multiwall carbon nanotube (MWCNT) arrays as conductive and super hydrophobic materials to have great interactive surface with the lipidic content of the solution. Results of the tests on the secretions of more than 100 human biopsied breast tissues showed the promising match between the charge transfer resistance (RCT) of samples' secretions and pathological states of the tissues with meaningful boundary (up to 8 kΩ for normal and more than 13 kΩ for cancer samples). Mass spectroscopic analyses confirmed the higher content of lipids in cancer secretomes. Electrical lipidomics of the secretome shed new lights in cell free cancer diagnosis and could be applied as a complementary clinical approach in all of biopsy based diagnoses in future.

Recent development on liquid chromatography-mass spectrometry analysis of oxidized lipids.

Polyunsaturated fatty acids (PUFAs) in the cellular membrane can be oxidized by various enzymes or reactive oxygen species (ROS) to form many oxidized lipids. These metabolites are highly bioactive, participating in a variety of physiological and pathophysiological processes. Mass spectrometry (MS), coupled with Liquid Chromatography, has been increasingly recognized as an indispensable tool for the analysis of oxidized lipids due to its excellent sensitivity and selectivity. We will give an update on the understanding of the molecular mechanisms related to generation of various oxidized lipids and recent progress on the development of LC-MS in the detection of these bioactive lipids derived from fatty acids, cholesterol esters, and phospholipids. The purpose of this review is to provide an overview of the formation mechanisms and technological advances in LC-MS for the study of oxidized lipids in human diseases, and to shed new light on the potential of using oxidized lipids as biomarkers and mechanistic clues of pathogenesis related to lipid metabolism. The key technical problems associated with analysis of oxidized lipids and challenges in the field will also discussed.

Omics analysis of oxysterols to better understand their pathophysiological role.

High amounts of cholesterol have been definitely associated with the pathogenesis of several diseases, including metabolic and neurodegenerative disorders, cardiovascular diseases, and cancer. In all these pathologies the exacerbation of pro-oxidant and inflammatory responses is a consistent feature. In this scenario, species derived from enzymatic and non-enzymatic cholesterol oxidation, namely oxysterols, are strongly suspected to play a primary role. The consideration of these bioactive lipids is therefore helpful in investigating pathological mechanisms and may also acquire clinical value for the diagnosis and treatment of diseases. For this purpose and considering that a great number of oxysterols may be present together in the body, the employment of lipidomics technology certainly represents a powerful strategy for the simultaneous detection and characterization of these compounds in biological specimens. In this review, we will discuss the applicability of the lipidomics approach in the study of the association between oxysterols and diseases.

Lipidomic methodologies for biomarkers of chronic inflammation in nutritional research: ω-3 and ω-6 lipid mediators.

The evolutionary history of hominins has been characterized by significant dietary changes, which include the introduction of meat eating, cooking, and the changes associated with plant and animal domestication. The Western pattern diet has been linked with the onset of chronic inflammation, and serious health problems including obesity, metabolic syndrome, and cardiovascular diseases. Diets enriched with ω-3 marine PUFAs have revealed additional improvements in health status associated to a reduction of proinflammatory ω-3 and ω-6 lipid mediators. Lipid mediators are produced from enzymatic and non-enzymatic oxidation of PUFAs. Interest in better understanding the occurrence of these metabolites has increased exponentially as a result of the growing evidence of their role on inflammatory processes, control of the immune system, cell signaling, onset of metabolic diseases, or even cancer. The scope of this review has been to highlight the recent findings on: a) the formation of lipid mediators and their role in different inflammatory and metabolic conditions, b) the direct use of lipid mediators as antiinflammatory drugs or the potential of new drugs as a new therapeutic option for the synthesis of antiinflammatory or resolving lipid mediators and c) the impact of nutritional interventions to modulate lipid mediators synthesis towards antiinflammatory conditions. In a second part, we have summarized methodological approaches (Lipidomics) for the accurate analysis of lipid mediators. Although several techniques have been used, most authors preferred the combination of SPE with LC-MS. Advantages and disadvantages of each method are herein addressed, as well as the main LC-MS difficulties and challenges for the establishment of new biomarkers and standardization of experimental designs, and finally to deepen the study of mechanisms involved on the inflammatory response.