Antiprotozoal activity of natural products from Nigerien plants used in folk medicine.

In the course of the screening of plants from Niger for antiprotozoal activity, the methanol extract of Cassia sieberiana, and the dichloromethane extracts of Ziziphus mauritiana and Sesamun alatum were found to be active against protozoan parasites, namely Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani and/or Plasmodium falciparum. Myricitrin (1), quercitrin (2) and 1-palmitoyl-lysolecithin (3) were isolated from C. sieberiana. From Z. mauritiana, the three triterpene derivatives 13, 15, and 16 are described here for the first time. Their chemical structures were determined by 1D and 2D NMR experiments, UV, IR and HRESIMS data. The absolute configurations were assigned via comparison of the experimental and calculated ECD spectra. In addition, eight known cyclopeptide alkaloids (4, 5, 7-12), and five known triterpenoids (6, 14, 17-19) were isolated. The antiprotozoal activity of the isolated compounds, as well as of eleven quinone derivatives (20-30) previously isolated from S. alatum was determined in vitro. The cytotoxicity in L6 rat myoblast cells was also evaluated. Compound 18 showed the highest antiplasmodial activity (IC50 = 0.2 µm) and compound 24 inhibited T. b. rhodesiense with an IC50 value of 0.007 µM. However, it also displayed significant cytotoxicity in L6 cells (IC50 = 0.4 µm).

Highlighting the Phototherapeutical Potential of Fungal Pigments in Various Fruiting Body Extracts with Informed Feature-Based Molecular Networking.

Fungal pigments are characterized by a diverse set of chemical backbones, some of which present photosensitizer-like structures. From the genus Cortinarius, for example, several biologically active photosensitizers have been identified leading to the hypothesis that photoactivity might be a more general phenomenon in the kingdom Fungi. This paper aims at testing the hypothesis. Forty-eight fruiting body-forming species producing pigments from all four major biosynthetic pathways (i.e., shikimate-chorismate, acetate-malonate, mevalonate, and nitrogen heterocycles) were selected and submitted to a workflow combining in vitro chemical and biological experiments with state-of-the-art metabolomics. Fungal extracts were profiled by high-resolution mass spectrometry and subsequently explored by spectral organization through feature-based molecular networking (FBMN), including advanced metabolite dereplication techniques. Additionally, the photochemical properties (i.e., light-dependent production of singlet oxygen), the phenolic content, and the (photo)cytotoxic activity of the extracts were studied. Different levels of photoactivity were found in species from all four metabolic groups, indicating that light-dependent effects are common among fungal pigments. In particular, extracts containing pigments from the acetate-malonate pathway, e.g., extracts from Bulgaria inquinans, Daldinia concentrica, and Cortinarius spp., were not only efficient producers of singlet oxygen but also exhibited photocytotoxicity against three different cancer cell lines. This study explores the distribution of photobiological traits in fruiting body forming fungi and highlights new sources for phototherapeutics.

Isolation and Structural Elucidation of Compounds from Pleiocarpa bicarpellata and Their In Vitro Antiprotozoal Activity.

Species of the genus Pleiocarpa are used in traditional medicine against fever and malaria. The present study focuses on the isolation and identification of bioactive compounds from P. bicarpellata extracts, and the evaluation of their antiprotozoal activity. Fractionation and isolation combined to LC-HRMS/MS-based dereplication provided 16 compounds: seven indole alkaloids, four indoline alkaloids, two secoiridoid glycosides, two iridoid glycosides, and one phenolic glucoside. One of the quaternary indole alkaloids (7) and one indoline alkaloid (15) have never been reported before. Their structures were elucidated by analysis of spectroscopic data, including 1D and 2D NMR experiments, UV, IR, and HRESIMS data. The absolute configurations were determined by comparison of the experimental and calculated ECD data. The extracts and isolated compounds were evaluated for their antiprotozoal activity towards Trypanosoma brucei rhodesiense, Trypanosoma cruzi, Leishmania donovani, and Plasmodium falciparum, as well as for their cytotoxicity against rat skeletal myoblast L6 cells. The dichloromethane/methanol (1:1) root extract showed strong activity against P. falciparum (IC50 value of 3.5 µg/mL). Among the compounds isolated, tubotaiwine (13) displayed the most significant antiplasmodial activity with an IC50 value of 8.5 µM and a selectivity index of 23.4. Therefore, P. bicarpallata extract can be considered as a source of indole alkaloids with antiplasmodial activity.

Metabolomics in Ecology and Bioactive Natural Products Discovery: Challenges and Prospects for a Comprehensive Study of the Specialised Metabolome.

Metabolomics is playing an increasingly prominent role in chemical ecology and in the discovery of bioactive natural products (NPs). The identification of metabolites is a common/central objective in both research fields. NPs have significant biological properties and play roles in multiple chemical-ecological interactions. Classically, in pharmacognosy, their chemical structure is determined after a complex process of isolating and interpreting spectroscopic data. With the advent of powerful analytical techniques such as liquid chromatography-mass spectrometry (LC-MS) the annotation process of the specialised metabolome of plants and microorganisms has improved considerably. In this article, we summarise the possibilities opened by these advances and illustrate how we harnessed them in our own research to automate annotations of NPs and target the isolation of key compounds. In addition, we are also discussing the analytical and computational challenges associated with these emerging approaches and their perspective.

Open and reusable annotated mass spectrometry dataset of a chemodiverse collection of 1,600 plant extracts.

As privileged structures, natural products often display potent biological activities. However, the discovery of novel bioactive scaffolds is often hampered by the chemical complexity of the biological matrices they are found in. Large natural extract collections are thus extremely valuable for their chemical novelty potential but also complicated to exploit in the frame of drug-discovery projects. In the end, it is the pure chemical substances that are desired for structural determination purposes and bioactivity evaluation. Researchers interested in the exploration of large and chemodiverse extract collections should thus establish strategies aiming to efficiently tackle such chemical complexity and access these structures. Establishing carefully crafted digital layers documenting the spectral and chemical complexity as well as bioactivity results of natural extracts collections can help prioritize time-consuming but mandatory isolation efforts. In this note, we report the results of our initial exploration of a collection of 1,600 plant extracts in the frame of a drug-discovery effort. After describing the taxonomic coverage of this collection, we present the results of its liquid chromatography high-resolution mass spectrometric profiling and the exploitation of these profiles using computational solutions. The resulting annotated mass spectral dataset and associated chemical and taxonomic metadata are made available to the community, and data reuse cases are proposed. We are currently continuing our exploration of this plant extract collection for drug-discovery purposes (notably looking for novel antitrypanosomatids, anti-infective and prometabolic compounds) and ecometabolomics insights. We believe that such a dataset can be exploited and reused by researchers interested in computational natural products exploration.

Phytochemical Investigation of the Roots of Ipomoea asarifolia and Antiproliferative Activity of the Isolated Compounds against Multiple Myeloma Cells.

Ipomoea asarifolia is a herbaceous plant belonging to the family Convolvulaceae and is native to tropical regions of Africa, America, and Asia. A dichloromethane root extract showed antiproliferative activity against multiple myeloma cells (RPMI 8226). The phytochemical investigation led to the isolation of 15 compounds. Compounds 1-4, named (4S,8S)-1-(furan-3-yl)-9-hydroxy-4,8-dimethylnonane-1,6-dione, isoferulic acid hexadecyl ester, caffeic acid hexadecyl ester, and asarifolin I, respectively, are described for the first time. The structures of these molecules were established from their NMR, UV, IR spectroscopic, and MS data. 4-Hydroxycinnamic acid hexadecyl ester (5), 4-hydroxycinnamic acid octadecyl ester (6), 4-hydroxycinnamic acid eicosyl ester (7), caffeic acid octadecyl ester (8), pescapreins III, IV, XXI, XXIII, XXV, and XXVI (9-14), and stoloniferin III (15) were also isolated. All compounds were tested against a multiple myeloma cell line (RPMI 8226). When their IC50 value was lower than 10 µM, the compounds were also tested against two other multiple myeloma cell lines, MM.1S and MM.1R. Compound 3 was the most potent, with an IC50 value of 3.0 µM against RPMI 8226 cells.

[Evaluation of the hypoglycemic effect of a peptide fraction of chia seeds (Salvia hispánica L.) in male Wistar rats induced with alloxan]. / Evaluación del efecto hipoglucemiante de una fracción peptídica de las semillas de chía (Salvia hispanica L.) en ratas macho Wistar inducidas con aloxano.

INTRODUCTION: Introduction: diabetes research with peptides from foods has been conducted in animal experiments to be later applied to humans. Objective: the main purpose of this work was to evaluate in rats the hypoglycemic effect of a peptide fraction of chia seeds derived by enzymatic hydrolysis. Materials and methods: from chia flour a protein-rich fraction was obtained, which was hydrolyzed with pepsin-pancreatin system enzymes to yield a peptide fraction (> 10 kDa) by ultrafiltration. Five rat groups (one normoglycemic and four diabetized with alloxan) were used. A sucrose tolerance curve was performed, providing the disaccharide before measurement. Blood was taken from the tip of the tail at 0 (before sugar), 30, 60, 90, and 120 minutes. Results: the protein content of chia flour was 49.51 %. The peptide fraction (> 10 kDa) had 91 % of protein. A dose of 50 mg/kg showed in rats a tendency to decrease blood glucose within the first hour, but no significance was found between the target and the doses evaluated. There was no decrease in glucose absorption vs. the reference drug. At 120 min postprandial, no differences were found between doses, water, and acarbose, showing a return to the baseline status. The tolerance curve in diabetic rats was opposite to that of acarbose, so there was no relationship between the drug's mechanism of action and this analyzed effect. Conclusion: the peptide fraction of chia of > 10 kDa showed no hypoglycemic effect at the single dose that was administered.

INTRODUCCIÓN: Introducción: se han realizado investigaciones sobre la diabetes con péptidos de diferentes fuentes alimentarias en animales experimentales para aplicarse después en los seres humanos. Objetivo: la finalidad de este trabajo fue evaluar en ratas el efecto hipoglucemiante de una fracción peptídica de chía obtenida por hidrólisis enzimática. Materiales y métodos: de la harina de chía se obtuvo una fracción rica en proteína que fue hidrolizada con pepsina-pancreatina, generándose una fracción peptídica (> 10 kDa) por ultrafiltración. Se utilizaron cinco grupos de ratas (uno de normoglucémicas y cuatro de diabetizadas con aloxano). Se realizó una curva de tolerancia a la sacarosa, proporcionándoles el disacárido antes de la medición. La sangre se tomó de la punta de la cola a los 0, 30, 60, 90 y 120 minutos. Resultados: el contenido proteico de la harina fue del 49,51 %. La fracción peptídica (> 10 kDa) presentó un 91 % de proteína; de esta se suministró una dosis de 50 mg/kg que demostró una tendencia a la disminución de la glucosa sanguínea en la primera hora, aunque no se encontró significancia entre el blanco y las dosis evaluadas. No hubo disminución de la absorción de glucosa frente al fármaco de referencia. A los 120 min del periodo postprandial no se encontraron diferencias entre las dosis, el blanco y la acarbosa, lo que denota un retorno al estado basal. Los valores en las ratas diabetizadas fueron opuestos a los de la acarbosa, por lo que no existió relación entre el mecanismo de acción del fármaco con el efecto analizado. Conclusión: las fracciones peptídicas de chía de > 10 kDa no presentaron efecto hipoglucemiante con la dosis única suministrada.

Kaempferol-3-O-α-(3,4-di-E-p-coumaroyl)-rhamnopyranoside from Nectandra oppositifolia releases Ca2+ from intracellular pools of Trypanosoma cruzi affecting the bioenergetics system.

Phytochemical analysis of EtOH extract from leaves of Nectandra oppositifolia afforded three flavonoids: kaempferol (1), kaempferol-3-O-α-rhamnopyranoside (2) and kaempferol-3-O-α-(3,4-di-E-p-coumaroyl)-rhamnopyranoside (3), which were characterized by NMR and ESI-HRMS. When tested against the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease, flavonoids 1 and 3 were effective to kill the trypomastigotes with IC50 values of 32.0 and 6.7 µM, respectively, while flavonoid 2 was inactive. Isolated flavonoids 1-3 were also tested in mammalian fibroblasts and showed CC50 values of 24.8, 48.7 and 153.1 µM, respectively. Chemically, these results suggested that the free aglycone plays an important role in the bioactivity while the presence of p-coumaroyl unities linked in the rhamnoside unity is important to enhance the antitrypanosomal activity and reduce the mammalian cytotoxicity. The mechanism of cellular death was investigated for the most potent flavonoid 3 in the trypomastigotes using fluorescent and luminescent-based assays. It indicated that this compound induced neither permeabilization of the plasma membrane nor depolarization of the membrane electric potential. However, early time incubation (20 min) with flavonoid 3 resulted in a constant elevation of the Ca2+ levels inside the parasite. This effect was followed by a mitochondrial imbalance, leading to a hyperpolarization and depolarization of the mitochondrial membrane potential, with reduction of the ATP levels. During this time, the levels of reactive oxygen species levels (ROS) were unaltered. The leakage of Ca2+ from the intracellular pools can affect the bioenergetics system of T. cruzi, leading to the parasite death. Therefore, flavonoid 3 can be a useful tool for future studies against T. cruzi parasites.

Constituents of Chamaecrista diphylla (L.) Greene Leaves with Potent Antioxidant Capacity: A Feature-Based Molecular Network Dereplication Approach.

Chamaecrista diphylla (L.) Greene (Fabaceae/Caesalpiniaceae) is a herbaceous plant that is widely distributed throughout the Americas. Plants from this genus have been used in traditional medicine as a laxative, to heal wounds, and to treat ulcers, snake and scorpion bites. In the present study, we investigated the chemical composition of Chamaecrista diphylla leaves through a mass spectrometry molecular network approach. The oxygen radical absorbance capacity (ORAC) for the ethanolic extract, enriched fractions and isolated compounds was assessed. Overall, thirty-five compounds were annotated for the first time in C. diphylla. Thirty-two of them were reported for the first time in the genus. The isolated compounds 9, 12, 24 and 33 showed an excellent antioxidant capacity, superior to the extract and enriched fractions. Bond dissociation energy calculations were performed to explain and sustain the antioxidant capacity found. According to our results, the leaves of C. diphylla represent a promising source of potent antioxidant compounds.

Metabolite profile of Nectandra oppositifolia Nees & Mart. and assessment of antitrypanosomal activity of bioactive compounds through efficiency analyses.

EtOH extracts from the leaves and twigs of Nectandra oppositifolia Nees & Mart. shown activity against amastigote forms of Trypanosoma cruzi. These extracts were subjected to successive liquid-liquid partitioning to afford bioactive CH2Cl2 fractions. UHPLC-TOF-HRMS/MS and molecular networking were used to obtain an overview of the phytochemical composition of these active fractions. Aiming to isolate the active compounds, both CH2Cl2 fractions were subjected to fractionation using medium pressure chromatography combined with semi-preparative HPLC-UV. Using this approach, twelve compounds (1-12) were isolated and identified by NMR and HRMS analysis. Several isolated compounds displayed activity against the amastigote forms of T. cruzi, especially ethyl protocatechuate (7) with EC50 value of 18.1 µM, similar to positive control benznidazole (18.7 µM). Considering the potential of compound 7, protocatechuic acid and its respective methyl (7a), n-propyl (7b), n-butyl (7c), n-pentyl (7d), and n-hexyl (7e) esters were tested. Regarding antitrypanosomal activity, protocatechuic acid and compound 7a were inactive, while 7b-7e exhibited EC50 values from 20.4 to 11.7 µM, without cytotoxicity to mammalian cells. These results suggest that lipophilicity and molecular complexity play an important role in the activity while efficiency analysis indicates that the natural compound 7 is a promising prototype for further modifications to obtain compounds effective against the intracellular forms of T. cruzi.

CD36 gene polymorphism -31118 G > A (rs1761667) is associated with overweight and obesity but not with fat preferences in Mexican children.

CD36 glycoprotein is a candidate receptor involved in the gustatory detection of lipids and emerging evidence has suggested that genetic variations in CD36 may modulate the oral perception threshold to fatty acids. Here, we analyzed the association of -31118 G > A polymorphism in CD36 gene with nutritional status and preferences for fatty foods in Mexican children. Genotyping of SNP rs1761667 was performed in school-age children (n = 63) in addition to sensory tests evaluating the preference and satisfaction score assigned to oil-based sauces of different fatty acid composition. The G allele was associated with high BMI z-score in children (OR = 2.43, 95% (CI 1.02-5.99); p = 0.02) but CD36 genotypes (AA, GA, and GG) did not show significant association with the preference and satisfaction scores assigned to oil-based sauces. The BMI z-score showed no association with the preference to oil-based sauces; however, children with normal weight gave higher satisfaction scores to sauces with a high content of unsaturated fatty acids than to sauces rich in saturated fatty acids (0.56 ± 1.26 vs. 0.06 ± 1.22; p = 0.02). Therefore, the G allele of -31118 G > A SNP in CD36 gene is associated with overweight and obesity in Mexican children but do not appear to modulate the preferences and satisfaction scores to fat.

Tackling Pseudomonas aeruginosa Virulence by Mulinane-Like Diterpenoids from Azorella atacamensis.

Pseudomonas aeruginosa is an important multidrug-resistant human pathogen by dint of its high intrinsic, acquired, and adaptive resistance mechanisms, causing great concern for immune-compromised individuals and public health. Additionally, P. aeruginosa resilience lies in the production of a myriad of virulence factors, which are known to be tightly regulated by the quorum sensing (QS) system. Anti-virulence therapy has been adopted as an innovative alternative approach to circumvent bacterial antibiotic resistance. Since plants are known repositories of natural phytochemicals, herein, we explored the anti-virulence potential of Azorella atacamensis, a medicinal plant from the Taira Atacama community (Calama, Chile), against P. aeruginosa. Interestingly, A. atacamensis extract (AaE) conferred a significant protection for human lung cells and Caenorhabditis elegans nematodes towards P. aeruginosa pathogenicity. The production of key virulence factors was decreased upon AaE exposure without affecting P. aeruginosa growth. In addition, AaE was able to decrease QS-molecules production. Furthermore, metabolite profiling of AaE and its derived fractions achieved by combination of a molecular network and in silico annotation allowed the putative identification of fourteen diterpenoids bearing a mulinane-like skeleton. Remarkably, this unique interesting group of diterpenoids seems to be responsible for the interference with virulence factors as well as on the perturbation of membrane homeostasis of P. aeruginosa. Hence, there was a significant increase in membrane stiffness, which appears to be modulated by the cell wall stress response ECFσ SigX, an extracytoplasmic function sigma factor involved in membrane homeostasis as well as P. aeruginosa virulence.

A Cecropia peltata ethanolic extract reduces insulin resistance and hepatic steatosis in rats fed a high-fat diet.

ETHNOPHARMACOLOGICAL RELEVANCE: Cecropia peltata L. (CP) leaves have been used in Latin American traditional medicine by its purported hypoglycemic, anti-inflammatory and antioxidant properties. PURPOSE: The aim of this study was to evaluate the metabolic effects of an ethanolic extract of CP leaves in rats fed a high-fat diet and 10% of sugar in water (HFD). METHODS: Male Wistar rats were randomly divided into four groups: group 1 was fed a control diet; groups 2, 3 and 4 were fed a HFD. In addition, group 3 was co-administered with 10 mg/kg/day of CP extract (HFD + CP) and group 4 with a solution of 5 mg/kg/day metformin (HFD + M) for 90 days. RESULTS: Body weight gain and serum triglycerides were significantly decreased in the HFD + CP group compared with the HFD and HFD + M groups. Glucose tolerance increased in the HFD + CP compared with the HFD group. Administration with CP extract reduced adipose tissue lipolysis and lipid accumulation in liver of HFD + CP rats with respect to HFD and HFD + M groups. Histological examinations showed that the area of the adipocytes in WAT and the area of lipid vesicles in BAT were significantly smaller in the HFD + CP group than in the HFD and HFD + M groups. CONCLUSION: Administration of a CP extract prevented glucose intolerance and hepatic lipid accumulation in rats fed a HFD in association with reduced adipocyte hypertrophy, demonstrating potential antidiabetic properties.

Phenolic variation among Chamaecrista nictitans subspecies and varieties revealed through UPLC-ESI(-)-MS/MS chemical fingerprinting.

INTRODUCTION: Comparative analysis of metabolic features of plants has a high potential for determination of quality control of active ingredients, ecological or chemotaxonomic purposes. Specifically, the development of efficient and rapid analytical tools that allow the differentiation among species, subspecies and varieties of plants is a relevant issue. Here we describe a multivariate model based on LC-MS/MS fingerprinting capable of discriminating between subspecies and varieties of the medicinal plant Chamaecrista nictitans, a rare distributed species in Costa Rica. METHODS: Determination of the chemical fingerprint was carried out on a LC-MS (ESI-QTOF) in negative ionization mode, main detected and putatively identified compounds included proanthocyanidin oligomers, several flavonoid C- and O-glycosides, and flavonoid acetates. Principal component analysis (PCA), partial least square-discriminant analysis (PLS-DA) and cluster analysis of chemical profiles were performed. RESULTS: Our method showed a clear discrimination between the subspecies and varieties of Chamaecrista nictitans, separating the samples into four fair differentiated groups: M1 = C. nictitans ssp. patellaria; M2 = C. nictitans ssp. disadena; M3 = C. nictitans ssp. nictitans var. jaliscensis and M4 = C. nictitans ssp. disadena var. pilosa. LC-MS/MS fingerprint data was validated using both morphological characters and DNA barcoding with ITS2 region. The comparison of the morphological characters against the chemical profiles and DNA barcoding shows a 63% coincidence, evidencing the morphological similarity in C. nictitans. On the other hand, genetic data and chemical profiles grouped all samples in a similar pattern, validating the functionality of our metabolomic approach. CONCLUSION: The metabolomic method described in this study allows a reliably differentiation between subspecies and varieties of C. nictitans using a straightforward protocol that lacks extensive purification steps.

[Inhibitory effect of peptide fractions derivatives from chia (Salvia hispanica) hydrolysis against α-amylase and α-glucosidase enzymes]. / Efecto inhibitorio de fracciones peptídicas derivadas de la hidrólisis de semillas de chía (Salvia hispanica) sobre las enzimas α-amilasa y α-glucosidasa.

INTRODUCTION: biopeptides are amino acid sequences with biological functions about metabolism and carbohydrates absorption. OBJECTIVE: the aim of this study was the evaluation of the inhibitory effect of peptide fractions derivatives of the hydrolysis of Salvia hispanica against α-amylase and α-glucosidase enzymes to know their activity on the carbohydrates metabolism. MATERIAL AND METHODS: the fraction rich in protein was hydrolyzed by two enzymatic systems: Alcalase®-Flavourzyme® and pepsin-pancreatine. The grade of hydrolysis was determined for the samples. The hydrolyzed samples were centrifuged and the soluble portion was ultra-filtered using different cut membranes. The content of protein was determined for each fraction. An in vitro analysis was made, measuring the percentage of inhibition of the Salvia hispanica fractions against α-amylase and α-glucosidase. RESULTS: the enzymatic system showing the highest grade of hydrolysis (63.53%) was pepsin-pancreatine. From the ultrafiltration, five peptide fractions were obtained: 10 kDa, 5-10 kDa, 3-5 kDa, 1-3 kDa and 1 kDa. The highest protein content was for these fractions: 10 kDa and 5-10 kDa, (0.90 and 0.93 mg/ml, respectively) for pepsin-pancreatine. The inhibition percentages obtained were 85.61% and 79.19% for the 10 kDa and 5-10 kDa fractions, respectively, for the α-amylase enzyme. With respect to the α-glucosidase enzyme, the highest inhibition was for the 10 kDa fraction, with 96.91%. CONCLUSION: the peptide fractions obtained from the chia may increase the natural sources for the preparation of functional foods important for the diabetic patient's diet.

Introducción: los biopéptidos son secuencias aminoacídicas que pueden ejercer funciones biológicas sobre el metabolismo y la absorción de carbohidratos.Objetivo: la finalidad de este estudio fue evaluar el efecto inhibitorio de fracciones peptídicas derivadas de la hidrólisis de Salvia hispanica sobre las enzimas α-amilasa y α-glucosidasa, para comprobar su actividad en el metabolismo glucídico. Material y métodos: se obtuvo una fracción rica en proteína, la cual fue hidrolizada mediante dos sistemas enzimáticos: Alcalasa®-Flavourzima® y pepsina-pancreatina. A las muestras obtenidas se les determinó el grado de hidrólisis. El hidrolizado fue centrifugado y la porción soluble fue ultrafiltrada, utilizando diferentes membranas de corte. A cada fracción se le determinó el contenido de proteína. Se realizó un análisis in vitro midiendo el porcentaje de inhibición de las fracciones de Salvia hispanica sobre α-amilasa y α-glucosidasa.Resultados: el sistema enzimático que presentó el mayor grado de hidrólisis (63,53%) fue la pepsina-pancreatina. De la ultrafiltración se obtuvieron cinco fracciones peptídicas: > 10 kDa, 5-10 kDa, 3-5 kDa, 1-3 kDa y < 1 kDa. El mayor contenido de proteína lo presentaron las fracciones de > 10 kDa y 5-10 kDa (0,90 y 0,93 mg/ml, respectivamente) para pepsina-pancreatina. Los porcentajes de inhibición obtenidos fueron de 85,61% y 79,19% para las fracciones de > 10 kDa y 5-10 kDa, respectivamente para la enzima α-amilasa. Para la enzima α-glucosidasa, el mayor porcentaje de inhibición fue para la fracción de > 10 kDa, con 96,91%.Conclusión: los péptidos obtenidos de la chía podrían incrementar las fuentes naturales para la elaboración de alimentos funcionales importantes para la dieta de pacientes diabéticos.

Evaluation of Hypotensive and Antihypertensive Effects of Velvet Bean (Mucuna pruriens L.) Hydrolysates.

Hypertension could cause significant worldwide health problems that affect 15-20% of all adults; according to National Health and Nutrition Examination Survey, about 29% of the adult population in the United States are hypertensive. Recent research has shown that peptides derived from the hydrolysis of food proteins can decrease blood pressure. This study was carried out to evaluate the hypotensive and antihypertensive potential of Mucuna pruriens protein hydrolysates in in vitro and in vivo models. M. pruriens protein concentrate was prepared by wet fractionation and enzymatically hydrolyzed using Alcalase®, Flavourzyme®, and the sequential system Alcalase-Flavourzyme at different times (5-120 min). The biological potential was measured in vitro based on the IC50 value as well as in vivo effect, measuring the systolic (SBP) and diastolic (DBP) blood pressure in normotensive and antihypertensive Wistar-Kyoto rats by the tail-cuff method. Hydrolysis of M. pruriens protein concentrates with commercial enzymes generated extensive hydrolysates with angiotensin-converting enzyme (ACE-I) inhibitory activity (IC50: 0.589-0.993 mg/mL) and hypotensive (SBP: 0.6-47.43%, DBP: 1.94-43.47%) and antihypertensive (SBP: 8.84-27.29% DBP: 16.1-29.37%) effect. These results indicate that Mucuna pruriens protein hydrolysate (MPPH) could be used as a functional ingredient to prevent blood pressure increase.

Evaluation of the Antihyperglycemic Effect of Minor Steviol Glycosides in Normoglycemic and Induced-Diabetic Wistar Rats.

Steviol glycosides are a family of compounds found in Stevia rebaudiana Bertoni that are responsible for sweetness capacity. The antihyperglycemic effect of the two major steviol glycosides, Rebaudioside A and Stevioside, has been studied and it has been found that despite having the same common structure, only Stevioside exerts an antihyperglycemic effect. Although other steviol derivatives are found in smaller amounts (minor steviol glycosides) in S. rebaudiana, whether or not they possess antihyperglycemic activity has not been evaluated. The aim of this study was to evaluate the antihyperglycemic effect of minor steviol glycosides in normoglycemic and diabetic (streptozotocin/nicotinamide) Wistar rats. Rats were subjected to an intraperitoneal glucose tolerance test (IPGTT) both before and after chronic treatment (28 days). After 6 h of fasting, IPGTT was conducted in pentobarbital-anesthetized rats using 1 g/kg of glucose plus 20 mg/kg of the minor glycoside (Dulcoside A, Rebaudioside B, C, D, or Steviolbioside) or control treatment (distilled water, glibenclamide, or metformin); the blood of the tip of the tail was collected at time 0, 15, 30, 60, and 120 min.; and blood glucose was measured, and its net area under the curve (AUCnet) was calculated. After 28-day chronic oral administration, IPGTT was again performed. Differences were considered significant at P < .05 by one-way ANOVA. Acute intraperitoneal or chronic oral administration of 20 mg/kg of minor steviol glycosides had no antihyperglycemic effect in normoglycemic or induced-diabetic Wistar rats. Considering the dose tested, it is unlikely that these glycosides have an effect on glucose in diabetic or normoglycemic humans.

Using Non-Traditional Interfaces to Support Physical Therapy for Knee Strengthening.

Physical therapy consists mainly in the execution of rehabilitation processes that aim to help overcome injuries, as well as develop, maintain, or restore maximum body movement. Knee rehabilitation is one kind of physical therapy that requires daily exercises which could be considered monotonous and boring by the patients, discouraging their improvement. This is coupled with the fact that most physical therapists assess exercise performance through verbal and visual means with mostly manual measurements, making it difficult to constantly verify and validate if patients perform the exercises correctly. This article describes a physical therapy monitoring system that uses wearable technology to assess exercise performance and patient progress. This wearable device is able to measure and transfer the movement's data from the patient's limb to a mobile device. Moreover, the user interface is a game, which provides an entertaining approach to therapy exercising. In this article, it is shown that the developed system significantly increases daily user engagement in rehabilitation exercises, through a gameplay that matches physical therapy requirements for knee rehabilitation, as well as offering useful quantitative information to therapists.

Chelating Properties of Peptides from Red Seaweed Pyropia columbina and Its Effect on Iron Bio-Accessibility.

The aim of this work was to evaluate copper-chelating, iron-chelating and anticariogenic activity of peptides obtained by enzymatic hydrolysis of P. columbina protein concentrate and to study the effects of chelating peptides on iron bio-accessibility. Two hydrolyzates were obtained from P. columbina protein concentrate (PC) using two hydrolysis systems: alkaline protease (A) and alkaline protease + Flavourzyme (AF). FPLC gel filtration profile of PC shows a peak having molecular weight (MW) higher than 7000 Da (proteins). A and AF hydrolyzates had peptides with medium and low MW (1013 and 270 Da), respectively. Additionally, AF presented free amino acids with MW around 82 Da and higher content of His and Ser. Peptides from AF showed the highest chelating properties measured as copper-chelating activity (the lowest ß-carotene oxidation rate: Ro; 0.7 min(-1)), iron-chelating activity (33%), and phosphorous and Ca(2+) release inhibition (87 and 81%, respectively). These properties could indicate antioxidant properties, promotion of iron absorption and anticariogenic activity, respectively. In fact, hydrolyzates promoted iron dialyzability (≈ 16%), values being higher than that found for P. columbina seaweed. Chelating peptides from both hydrolyzates can maintain the iron in a soluble and bio-accessible form after gastrointestinal digestion.

ACE-I Inhibitory Activity from Phaseolus lunatus and Phaseolus vulgaris Peptide Fractions Obtained by Ultrafiltration.

The involvement of angiotensin-I-converting enzyme (ACE-I) as one of the mechanisms controlling blood pressure is being studied to find alternative means of control of hypertension on human beings. On the market there are synthetic drugs that can control it, but these can cause undesirable health side effects. In this work was assessed the fractionation by ultrafiltration of the Lima bean (Phaseolus lunatus) and Jamapa bean (Phaseolus vulgaris), protein hydrolysates obtained with Alcalase(®) and Flavourzyme(®) on ACE-I inhibitory activity. Four membranes of different molecular cutoffs (10, 5, 3, and 1 kDa) were used. Fractions that had a higher inhibitory activity in both legumes were denominated as E (<1 kDa) with IC50 of 30.3 and 51.8 µg/mL values for the P. lunatus with Alcalase and Flavourzyme, respectively, and for the Phaseolus vulgaris with Alcalase and Flavourzyme with about 63.8 and 65.8 µg/mL values, respectively. The amino acid composition of these fractions showed residues in essential amino acids, which make a good source of energy and amino acids. On the other hand, the presence of hydrophobic amino acids such as V and P is a determining factor in the ACE-I inhibitor effect. The results suggest the possibility of obtaining and utilizing these peptide fractions in the development and innovation of a functional product that helps with treatment and/or prevention of hypertension.