Celia Rodríguez-Pérez

A metabolite-profiling approach allows the identification of new compounds from Pistacia lentiscus leaves.

Pistacia lentiscus L., commonly known as Mastic tree or lentisk, is a Mediterranean evergreen shrub widely used in traditional medicine to treat such diseases as eczema, diarrhoea, and throat infections. Furthermore, other properties are currently attributed to P. lentiscus, such as antioxidant capacity, hepatoprotective action, and anti-inflammatory effects. High-performance liquid chromatography with diode array coupled to electrospray ionization mass spectrometry (HPLC-ESI-QTOF-MS) was used for the comprehensive characterization of methanol extract from P. lentiscus leaves. After the optimisation of the HPLC-ESI-QTOF-MS method and the use of the negative ionization mode, 46 different compounds were identified, 20 of which were tentatively characterized for the first time in P. Lentiscus leaves. The majority of the compounds were quantified. Flavonoids, phenolic acids and their derivatives were the most abundant compounds, those with the highest concentrations being myricetin glycoside (6216.13 mg/kg of plant), catechin (3354.78 mg/kg of plant), β-glucogallin (2214.461 mg/kg of plant), and quercitrin gallate (1160 mg/kg of plant). The importance of the knowledge of plants is increasing and our study may help in the future to formulate nutraceutical preparations and will provide the basis for new investigation into activities of the various compounds found in P. lentiscus.

Tentative Characterisation of Iridoids, Phenylethanoid Glycosides and Flavonoid Derivatives from Globularia alypum L. (Globulariaceae) Leaves by LC‐ESI‐QTOF‐MS

INTRODUCTION Globularia alypum L., belonging to the Globulariaceae family, is a perennial wild shrub found throughout the Mediterranean area, Europe, and Africa. This plant is widely used to treat many diseases, but no previous work on the phytochemical composition of the Algerian G. alypum species has yet been reported. OBJECTIVE To investigate the phytoconstituents of the methanolic extract of G. alypum using an LC-ESI-QTOF-MS method. METHODS Ground air-dried leaves of G. alypum were macerated with methanol at room temperature for 24 h. The supernatant was filtered and concentrated to dryness under reduced pressure in a rotary evaporator, and extracts were recovered with methanol and filtered. Afterwards, the G. alypum extract was injected into the LC-ESI-QTOF-MS system. RESULTS The combined LC-MS/MS led to the tentative characterisation of 63 phytochemicals. In this work, a large number of compounds have been characterised in the leaf-extract analysis of this plant. Among others, 24 iridoids and secoiridoids were found, of which nine compounds have not previously been recorded in G. alypum. Also, nine unusual phenylethanoid glycosides were characterised for the first time in this species. CONCLUSION The method used has proved to be a valued tool for the characterisation of a wide range of compounds from G. alypum leaves. This work constitutes a detailed investigation of the chemical composition of G. alypum leaves, which are widely used in different traditional systems of medicine.

Optimization of microwave-assisted extraction and pressurized liquid extraction of phenolic compounds from Moringa oleifera leaves by multiresponse surface methodology

This work aims at studying the optimization of microwave‐assisted extraction (MAE) and pressurized liquid extraction (PLE) by multi‐response surface methodology (RSM) to test their efficiency towards the extraction of phenolic compounds from Moringa oleifera (M. oleifera) leaves. The extraction yield, total phenolic content (TPC), total flavonoid content (TF), DPPH scavenging method and trolox equivalent antioxidant capacity (TEAC) assay were considered as response variables while effects of extraction time, percentage of ethanol, and temperature were studied. Extraction time of 20 min, 42% ethanol and 158°C were the MAE optimum conditions for achieving extraction yield of 26 ± 2%, EC50 15 ± 2 μg/mL, 16 ± 1 Eq Trolox/100 g dry leaf, 5.2 ± 0.5 mg Eq quercetin/g dry leaf, and 86 ± 4 mg GAE/g dry leaf. Regarding PLE, the optimum conditions that allowed extraction yield of 56 ± 2%, EC50 21 ± 3 μg/mL, 12 ± 2 mmol Eq Trolox/100 g dry leaf, 6.5 ± 0.2 mg Eq quercetin/g dry leaf, and 59 ± 6 mg GAE/g dry leaf were 128°C, 35% of ethanol, and 20 min. PLE enabled the extraction of phenolic compounds with a higher number of hydroxyl‐type substituents such as kaempferol diglycoside and its acetyl derivatives and those that are sensitive to high temperatures (glucosinolates or amino acids) while MAE allowed better recoveries of kaempferol, quercetin, and their glucosides derivatives.

Assessment of the stability of proanthocyanidins and other phenolic compounds in cranberry syrup after gamma-irradiation treatment and during storage.

Shelf life of commercial cranberry syrup irradiated with gamma radiation at a rate of 5 kGy and stored for 6 months at 25 °C and 60% relative humidity (RH) and under accelerated stability conditions was investigated. High-performance liquid chromatography coupled to electrospray ionisation quadrupole-time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS) was used to characterise cranberry syrup. Afterwards, these compounds were quantified by HPLC-ESI-QTOF-MS and 4-dimethylaminocinnamaldehyde (DMAC) assay. A significant increase in the content of procyanidin B isomer 1 (from 4.4 to 7.0 μg/ml) and procyanidin A2 (from 83 to 93 μg/ml) was observed after irradiation and compared with the non-irradiated syrup. Procyanidin B isomers and prodelphinidin were stable at 25 °C during the first month of storage, whereas quercetin and some derivatives remained constant for 3 months of storage at this temperature. In short, after gamma-irradiation in dose of 5 kGy, most compounds were highly stable for a month at 25 °C.

AMPK modulatory activity of olive–tree leaves phenolic compounds: Bioassay-guided isolation on adipocyte model and in silico approach

Scope Olive-tree polyphenols have demonstrated potential for the management of obesity-related pathologies. We aimed to explore the capacity of Olive-tree leaves extract to modulate triglyceride accumulation and AMP-activated protein kinase activity (AMPK) on a hypertrophic adipocyte model. Methods Intracellular triglycerides and AMPK activity were measured on the hypertrophic 3T3-L1 adipocyte model by AdipoRed and immunofluorescence microscopy, respectively. Reverse phase high performance liquid chromatography coupled to time-of-flight mass detection with electrospray ionization (RP-HPLC-ESI-TOF/MS) was used for the fractionation of the extract and the identification of the compounds. In-silico molecular docking of the AMPK alpha-2, beta and gamma subunits with the identified compounds was performed. Results Olive-tree leaves extract decreased the intracellular lipid accumulation through AMPK-dependent mechanisms in hypertrophic adipocytes. Secoiridoids, cinnamic acids, phenylethanoids and phenylpropanoids, flavonoids and lignans were the candidates predicted to account for this effect. Molecular docking revealed that some compounds may be AMPK-gamma modulators. The modulatory effects of compounds over the alpha and beta AMPK subunits appear to be less probable. Conclusions Olive-tree leaves polyphenols modulate AMPK activity, which may become a therapeutic aid in the management of obesity-associated disturbances. The natural occurrence of these compounds may have important nutritional implications for the design of functional ingredients.

Phenolic compounds as natural and multifunctional anti-obesity agents: A review

ABSTRACT Prevalence of obesity worldwide has reached pandemic proportions. Despite the increasing evidence in the implication of phenolic compounds in obesity management, the real effect is not completely understood. The available in vitro and in vivo studies have demonstrated the implication of phenolic compounds in: lowering food intake, decreasing lipogenesis, increasing lipolysis, stimulating fatty acids β-oxidation, inhibiting adipocyte differentiation and growth, attenuating inflammatory responses and suppress oxidative stress. This review encompasses the most recent evidence in the anti-obesity effect of phenolic compounds from plants to different nutraceuticals and functional foods based on the in vitro, in vivo and clinical studies. For that, this review has been focused on popular plant-based products highly consumed today such as cocoa, cinnamon, and olive oil, beverages such as red wine, tea (green, white and black tea) and Hibiscus sabdariffa L. tea, among others.

Dietary high oleic canola oil supplemented with docosahexaenoic acid attenuates plasma proprotein convertase subtilisin kexin type 9 (PCSK9) levels in participants with cardiovascular disease risk: A randomized control trial.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a novel circulating protein which plays an important role in regulation of cholesterol metabolism by promoting hepatic LDL receptor degradation. However, the action of dietary fat composition on PCSK9 levels remains to be fully elucidated. The objective was to investigate the action of different dietary oils on circulating PCSK9 levels in the Canola Oil Multicenter Intervention Trial (COMIT). COMIT employed a double-blinded crossover randomized control design, consisting of five 30-d treatment periods. Diets were provided based on a 3000Kcal/d intake, including a 60g/d treatment of conventional canola oil (Canola), a high oleic canola/DHA oil blend (CanolaDHA), a corn/safflower oil blend (CornSaff), a flax/safflower oil blend (FlaxSaff) or a high oleic canola oil (CanolaOleic). Plasma PCSK9 levels were assessed using ELISA at the end of each phase. Lipid profiles (n=84) showed that CanolaDHA feeding resulted in the highest (P<0.05) serum total cholesterol (TC, 5.06±0.09mmol/L) and LDL-cholesterol levels (3.15±0.08mmol/L) across all five treatments. CanolaDHA feeding also produced the lowest (P<0.05) plasma PCSK9 concentrations (216.42±8.77ng/mL) compared to other dietary oil treatments. Plasma PCSK9 levels positively correlated (P<0.05) with serum TC, LDL-cholesterol, apolipoprotein A, and apolipoprotein B levels but did not correlate to HDL-cholesterol levels. Results indicate that post-treatment response in PCSK9 may be altered with the CanolaDHA diet. In conclusion, the elevated LDL-C levels from a DHA oil treatment may not be relevant for the observed decline in PCSK9 levels.

Comprehensive metabolite profiling of Solanum tuberosum L. (potato) leaves by HPLC-ESI-QTOF-MS

The objective of this work was to study the non-targeted metabolite profiling of potato leaves using high performance liquid chromatography coupled to quadrupole-time of flight mass spectrometry (HPLC-ESI-QTOF-MS). The mass accuracy, true isotopic pattern in both MS and MS/MS spectra provided by QTOF-MS made possible the tentative identification of 109 compounds present in potato leaves, including organic acids, amino acids and derivatives, phenolic acids, flavonoids, iridoids, oxylipins and other polar and semi-polar compounds. Among them, 32 compounds have been found for the first time in potato leaf and in the Solanaceae family. Quinic acid and its derivatives represented more than 45% of the bioactive compounds quantified in the extract. Derivatives of hydroxybenzoic acid and gentisic acid were also founded at considerable concentrations. This study shed light on the composition of potato leaf extract and will serve as a base for further research into activities of the various compounds found in this matrix which has demonstrated a potential use as functional ingredients.

Development and stability evaluation of water-in-edible oils emulsions formulated with the incorporation of hydrophilic Hibiscus sabdariffa extract

New functional oils (extra virgin olive oil, EVOO and sunflower oil, SO) containing antioxidants from Hibiscus sabdariffa extract were developed by W/O emulsion. Their physical and chemical stability was measured over time. The lowest coalescence rate was obtained with 8 and 12 wt% surfactant amount for EVOO and SO emulsions, respectively. Before the evaluation of the oxidative stability, an optimization of phenolic compounds extraction from emulsions by multi-response surface methodology was performed. EVOO emulsions were chemically more stable over time than SO emulsions in terms of total phenolic content (TPC), antioxidant activity and chemical composition measured by HPLC-ESI.TOF-MS. TPC significantly increased (from 2.02 ± 0.07 to 2.71 ± 0.06 mg Eq GAE/g extract) and the antioxidant activity measured by TEAC remained constant for 1 month of storage. Thus, W/O emulsion technology has proven to be a potential method to vehiculize and stabilize bioactive compounds from H. sabdariffa into edible oils.