Pharmacological Activities and Chemical Stability of Natural and Enzymatically Acylated Anthocyanins: A Comparative Review.

Anthocyanins (ANCs) are naturally occurring water-soluble pigments responsible for conferring red, blue, and purple colors to fruits, vegetables, flowers, and grains. Due to their chemical structure, they are highly susceptible to degradation by external factors, such as pH, light, temperature, and oxygen. Naturally acylated anthocyanins have proven to be more stable in response to external factors and exhibit superior biological effects as compared with their non-acylated analogues. Therefore, synthetic acylation represents a viable alternative to make the application of these compounds more suitable for use. Enzyme-mediated synthetic acylation produces derivatives that are highly similar to those obtained through the natural acylation process, with the main difference between these two pathways being the catalytic site of the enzymes involved in the synthesis; acyltransferases catalyze natural acylation, while lipases catalyze synthetic acylation. In both cases, their active sites perform the addition of carbon chains to the hydroxyl groups of anthocyanin glycosyl moieties. Currently, there is no comparative information regarding natural and enzymatically acylated anthocyanins. In this sense, the aim of this review is to compare natural and enzyme-mediated synthetic acylated anthocyanins in terms of chemical stability and pharmacological activity with a focus on inflammation and diabetes.

Common beans as a source of food ingredients: Techno-functional and biological potential.

Common beans are an inexpensive source of high-quality food ingredients. They are rich in proteins, slowly digestible starch, fiber, phenolic compounds, and other bioactive molecules that could be separated and processed to obtain value-added ingredients with techno-functional and biological potential. The use of common beans in the food industry is a promising alternative to add nutritional and functional ingredients with a low impact on overall consumer acceptance. Researchers are evaluating traditional and novel technologies to develop functionally enhanced common bean ingredients, such as flours, proteins, starch powders, and phenolic extracts that could be introduced as functional ingredient alternatives in the food industry. This review compiles recent information on processing, techno-functional properties, food applications, and the biological potential of common bean ingredients. The evidence shows that incorporating an adequate proportion of common bean ingredients into regular foods such as pasta, bread, or nutritional bars improves their fiber, protein, phenolic compounds, and glycemic index profile without considerably affecting their organoleptic properties. Additionally, common bean consumption has shown health benefits in the gut microbiome, weight control, and the reduction of the risk of developing noncommunicable diseases. However, food matrix interaction studies and comprehensive clinical trials are needed to develop common bean ingredient applications and validate the health benefits over time.

Food-derived bioactive compounds with anti-aging potential for nutricosmetic and cosmeceutical products.

Besides providing essential nutrients for humans, food contains bioactive compounds that exert diverse biological activities such as anti-microbial, anti-cancerogenic, anti-viral, anti-inflammatory and antioxidant. The cosmetic industry is interested in natural bioactive compounds for their use in nutricosmetic and cosmeceutical products. These products aimed to reduce skin aging, inflammation or provide photoprotection against UV radiation. As a result, nutricosmetics and cosmeceuticals are becoming innovative self-care products in the beauty market. These products contain phytochemicals as active compounds obtained from fruits, vegetables, legumes, medicinal herbs and plants with anti-aging potential. This review summarizes the information within the last 5 years related to bioactive compounds present in fruits, vegetables, herbs and spices commonly used for human consumption. Their antioxidant and biological potential for modulating molecular markers involved in the aging process, as well as their mechanism of action. Diverse natural foods and their byproducts could be used as a source of bioactive compounds for developing cosmeceutical and nutricosmetic products.

Activating Effects of Phenolics from Apache Red Zea mays L. on Free Fatty Acid Receptor 1 and Glucokinase Evaluated with a Dual Culture System with Epithelial, Pancreatic, and Liver Cells.

The aim was to characterize a phenolic-rich water extract from the pericarp of an improved genotype of Apache red maize (RPE) and evaluate its ability to activate the type 2 diabetes markers free fatty acid receptor 1 (GPR40) and glucokinase (GK) in vitro. The extract contained mainly phenolic acids, anthocyanins, and other flavonoids. RPE inhibited α-amylase (IC50 = 88.3 µg/mL), α-glucosidase (IC50 = 169.3 µg/mL), and reduced glucose transport in a Caco-2 cell monolayer (up to 25%). Furthermore, RPE activated GPR40 (EC50 = 77.7 µg/mL) in pancreatic INS-1E cells and GK (EC50 = 43.4 µg/mL) in liver HepG2 cells, potentially through allosteric modulation. RPE activated GPR40-related insulin secretory pathway and activated the glucose metabolism regulator AMPK (up to 78%). Our results support the hypothesis that foods with a high concentration of anthocyanins and phenolic acids, such as in the selected variety of maize used, could ameliorate obesity and type 2 diabetes comorbidities.

Anthocyanins from purple corn activate free fatty acid-receptor 1 and glucokinase enhancing in vitro insulin secretion and hepatic glucose uptake.

The objective of this study was to evaluate the ability of anthocyanins (ANC) present in purple corn to enhance insulin secretion and hepatic glucose uptake in pancreatic cells and hepatocytes, through activation of the free fatty acid receptor-1 (FFAR1) and glucokinase (GK), respectively. Using a dual-layer cell culture with Caco-2 cells, INS-1E or HepG2 cells were treated with an anthocyanin-rich extract from the pericarp of purple corn (PCW), as well as pure ANC cyanidin-3-O-glucoside (C3G), peonidin-3-O-glucoside, pelargonidin-3-O-glucoside. Delphinidin-3-O-glucoside (D3G) was used for comparative purposes. Semipurified C3G (C3G-P) and condensed forms (CF-P) isolated from PCW were also used. At 100 µM, the pure ANC enhanced glucose-stimulated insulin secretion (GSIS) in INS-1E cells ranging from 18% to 40% (p<0.05) compared to untreated cells. PCW increased GSIS by 51%. D3G was the most effective anthocyanin activating FFAR1 (EC50: 196.6 µM). PCW had activating potential on FFAR1 (EC50: 77 µg/mL). PCW, as well as C3G and D3G increased the expression of FFAR1, PLC, and phosphorylation of PKD, related to the FFAR1-dependent insulin secretory pathway. The treatment with 100 µM of P3G and C3G increased (p<0.05) glucose uptake in HepG2 cells by 19% and 31%. PCW increased the glucose uptake in HepG2 cells by 48%. It was determined that CF-P was the most effective for activating GK (EC50: 39.9 µM) and the PCW extracts had an efficacy of EC50: 44 µg/mL. The ANC in purple corn also reduced AMPK phosphorylation and PEPCK expression in HepG2 cells, known to be related to reduction in gluconeogenesis. It is demonstrated for the first time that dietary ANC can enhance the activity of novel biomarkers FFAR1 and GK and potentially ameliorate type-2 diabetes comorbidities.

Black bean peptides inhibit glucose uptake in Caco-2 adenocarcinoma cells by blocking the expression and translocation pathway of glucose transporters.

The objective was to evaluate the effect of black bean protein fraction (PFRA), and its derived peptides on glucose uptake, SGLT1 and GLUT2 expression and translocation on Caco-2 cells. The effect of treatments was evaluated on glucose uptake, protein expression and localization and gene expression on Caco-2 cells. PFRA (10 mg/mL) lowered glucose uptake from 27.4% after 30 min to 33.9% after 180 min of treatment compared to untreated control (p < 0.05). All treatments lowered GLUT2 expression after 30 min of treatment compared to untreated control (31.4 to 48.6%, p < 0.05). Similarly, after 24 h of treatment, GLUT2 was decreased in all treatments (23.5% to 48.9%) (p < 0.05). SGLT1 protein expression decreased 18.3% for LSVSVL (100 µM) to 45.1% for PFRA (10 mg/mL) after 24 h. Immunofluorescence microscopy showed a decrease in expression and membrane translocation of GLUT2 and SGLT1 for all treatments compared to untreated control (p < 0.05). Relative gene expression of SLC2A2 (GLUT2) and SLC5A1 (SGLT1) was downregulated significantly up to two-fold change compared to the untreated control after 24 h treatment. Black bean protein fractions are an inexpensive, functional ingredient with significant biological potential to reduce glucose uptake and could be used as an adjuvant in the treatment of colorectal cancer.

Extraction techniques and analysis of anthocyanins from food sources by mass spectrometry: An update.

This article reviews recent developments in methods of sample preparation and analytical methodologies for the quantification of anthocyanins and their extraction from food sources. Various methods for sample extraction and purification are highlighted and evaluated. The use of UV-diode array, along with improved liquid chromatography (LC) and mass spectrometry (MS) and/or the combination of both methods have facilitated the identification of analytes. The use of one-dimensional and two-dimensional HPLC has significantly improved resolution with a shorter amount of time. Other LC × LC combinations to improve orthogonality are also discussed. The most efficient anthocyanin extraction method from food sources is pressurized liquid extraction. Moreover, electrospray ionization (ESI) and MS2/time-of-flight are currently the most popular instruments used for identification of anthocyanins; being positive mode of ESI the most widely used procedure for anthocyanin identification. Several databases for mass spectrometry polyphenol identification have been described for reference.

Dietary Peptides from Phaseolus vulgaris L. Reduced AOM/DSS-Induced Colitis-Associated Colon Carcinogenesis in Balb/c Mice.

The aim was to evaluate the antineoplastic potential of a previously characterized peptide extract from the non-digestible fraction of common bean cv. Azufrado Higuera (AH) and its most abundant pure peptide GLTSK, in an azoxymethane/dextran sodium sulfate (AOM/DSS)-induced colitis-associated colon carcinogenesis Balb/c mice model. The healthy control (C-) had no induction and no treatment, and the induced control (C+) had induction but no treatment. Groups AH and GLTSK were administered 50 mg/kg-bw of AH or GLTSK, respectively. The administration of AH and GLTSK decreased (p < 0.05) the disease activity index (DAI) compared to C+ (5.8, 9.1, 11.8, respectively). Furthermore, AH reduced the number of evident neoplasms compared to group C+ (1.8, 5.9 neoplasms/mice, respectively). The results suggest that peptides from common bean cv. Azufrado Higuera could prevent colitis-associated colon carcinogenesis.

Characterization of peptides from common bean protein isolates and their potential to inhibit markers of type-2 diabetes, hypertension and oxidative stress.

BACKGROUND: Diabetes and hypertension are diseases affecting a high proportion of the world population; the use of food-based products such as common bean peptides may contribute to reduce the risk of complications associated to chronic diseases. The aim was to produce and characterize peptides from common bean protein isolates and evaluate their potential to inhibit markers of type-2 diabetes, hypertension and oxidative stress. RESULTS: Mexican black and Brazilian Carioca bean isolated proteins were characterized after pepsin/pancreatin digestion. Also, four synthesized pure peptides, originally found in these beans, were evaluated. Bean protein digests and pure peptides exerted dipeptidyl peptidase-IV (DPP-IV) inhibition (IC50 = 0.03-0.87 mg dry weight (DW) mL-1 ). Lineweaver-Burk plots and computational modeling showed competitive inhibition of DPP-IV. Angiotensin-converting enzyme (ACE) inhibition ranged from IC50 = 0.09 to 0.99 mg DW mL-1 , and α-glucosidase inhibition ranged from 36.3 to 50.1% mg-1 DW. Carioca Perola bean digested proteins presented the highest antioxidant capacity (269.3 mmol L-1 Trolox equivalent g-1 DW) as the peptide KTYGL (P > 0.05) with the most potent DPP-IV and ACE inhibition. CONCLUSION: Peptides from common bean have antidiabetic and antihypertensive potential regardless of their antioxidant capacity. © 2016 Society of Chemical Industry.

Dietary peptides from the non-digestible fraction of Phaseolus vulgaris L. decrease angiotensin II-dependent proliferation in HCT116 human colorectal cancer cells through the blockade of the renin-angiotensin system.

This study aimed to determine the ability of peptides present in the non-digestible fraction (NDF) of common beans to decrease angiotensin II (AngII) through the blockade of RAS and its effect on the proliferation of HCT116 human colorectal cancer cells. Pure synthesized peptides GLTSK and GEGSGA and the peptide fractions (PF) of cultivars Azufrado Higuera and Bayo Madero were used. The cells were pretreated with pure peptides, PF or AGT at their IC50 or IC25 values, in comparison with the simultaneous treatment of peptides and AGT. For western blot and microscopy analysis, 100 µM and 0.5 mg mL(-1) were used for pure peptides and PF treatments, respectively. According to the ELISA tests, GLTSK and GEGSGA decreased (p < 0.05) the conversion rate of AGT to angiotensin I (AngI) by 38 and 28%, respectively. All the peptides tested reduced (p < 0.05) the conversion rate of AngI to AngII from 38 to 50%. When the cells were pretreated with both pure peptides and PF before exposure to AGT, the effectiveness inhibiting cell proliferation was higher than the simultaneous treatment suggesting their preventive effects. GLTSK and GEGSGA interacted with the catalytic site of renin, the angiotensin-I converting enzyme, and the AngII receptor, mainly through hydrogen bonds, polar, hydrophobic and cation-π interactions according to molecular docking. Through confocal microscopy, it was determined that GLTSK and GEGSGA caused the decrease (p < 0.05) of AngII-dependent STAT3 nuclear activation in HCT116 cells by 66 and 23%, respectively. The results suggest that peptides present in the common bean NDF could potentially ameliorate the effects of RAS overexpression in colorectal cancer.

Peptides present in the non-digestible fraction of common beans (Phaseolus vulgaris L.) inhibit the angiotensin-I converting enzyme by interacting with its catalytic cavity independent of their antioxidant capacity.

The aim was to evaluate the angiotensin-I converting enzyme (ACE) inhibitory potential and the antioxidant capacity of pure synthesized peptides (GLTSK, LSGNK, GEGSGA, MPACGSS and MTEEY) originally identified in the non-digestible fraction (NDF) of common beans (P. vulgaris L.) that had previously demonstrated antiproliferative activity against human colorectal cancer cells. The five peptides were able to inhibit ACE with half maximal inhibitory concentration (IC50) values ranging from 65.4 (GLTSK) to 191.5 µM (MPACGSS). The combination of GLTSK and MTEEY increased the ACE inhibition by 30% compared to equieffective doses of the single peptides. According to molecular docking analysis, the five peptides had lower estimated free energy values (-6.47 to -9.34 kcal mol(-1)) when they interacted with the catalytic site of ACE than that of the substrate hippuryl-histidyl-leucine (-5.41 kcal mol(-1)), thus inhibiting the enzymatic activity. According to molecular docking analysis, the five peptides interacted with four (His353, Ala354, Glu411 and Tyr523) out of 6 catalytic residues. Moreover, MPACGSS had the highest antioxidant activity according to Ferric reducing antioxidant power (FRAP) (421.58 µmol FeSO4 mg(-1)), Fe(2+) chelation (2.01 µmol Na2EDTA mg(-1)) assays, and also in DPPH (748.39 µmol Trolox per mg of dry peptide) and ABTS (561.42 µmol Trolox mg(-1)) radical scavenging assays. The results support the hypothesis that peptides present in the non-digestible fraction of common beans (Phaseolus vulgaris L.) may exert their physiological benefits independent of their antioxidant capacity, by ACE inhibition through interaction with its catalytic cavity.

Peptides in common bean fractions inhibit human colorectal cancer cells.

The aim of this study was to characterize peptides present in common bean non-digestible fractions (NDF) produced after enzymatic digestion and determine their antiproliferative action on human colorectal cancer cells. Five NDF peptides represented 70% of total protein (GLTSK, LSGNK, GEGSGA, MPACGSS and MTEEY) with antiproliferative activity on human colon cancer cells. Based on the antiproliferative effect, HCT116 cell line was most sensitive to bean Azufrado Higuera (IC50=0.53 mg/ml) and RKO to Bayo Madero (IC50=0.51 mg/ml) peptide extracts. Both cultivars increased significantly (p<0.05) the expression of p53 in HCT116 by 76% and 68%, respectively. Azufrado Higuera modified the expression of cell cycle regulation proteins p21 and cyclin B1. Bayo Madero modified the expression of mitochondrial activated apoptotic proteins BAD, cytC, c-casp3, Survivin, BIRC7. Results suggest that peptides present in common bean NDF contributed to the antiproliferative effect on human colorectal cancer cells by modifying molecules involved in either cell cycle arrest or apoptosis.