Gallic Acid Content and an Antioxidant Mechanism Are Responsible for the Antiproliferative Activity of 'Ataulfo' Mango Peel on LS180 Cells

Genotoxic and antiproliferative properties of Endopleura uchi bark aqueous extract

The bark extract from Endopleura uchi has been widely used in traditional medicine to treat gynecological-related disorders, diabetes, and dyslipidemias albeit without scientific proof. In addition, E. uchi bark extract safety, especially regarding mutagenic activities, is not known. The aim of this study was to determine the chemical composition, antitumor, and toxicological parameters attributed to an E. uchi bark aqueous extract. The phytochemical constitution was assessed by colorimetric and chromatographic analyzes. The antiproliferative effect was determined using sulforhodamine B (SRB) assay using 4 cancer cell lines. Cytotoxic and genotoxic activities were assessed utilizing MTT and comet assays, respectively, while mutagenicity was determined through micronucleus and Salmonella/microsome assays. The chromatographic analysis detected predominantly the presence of gallic acid and isoquercitrin. The antiproliferative effect was more pronounced in human colon adenocarcinoma (HT-29) and human breast cancer (MCF-7) cell lines. In the MTT assay, the extract presented an IC50 = 39.1 µg/ml and exhibited genotoxic (comet assay) and mutagenic (micronucleus test) activities at 20 and 40 µg/ml in mouse fibroblast cell line (L929) and mutagenicity in the TA102 and TA97a strains in the absence of S9 mix. Data demonstrated that E. uchi bark possesses bioactive compounds which exert cytotoxic and genotoxic effects that might be associated with its antitumor potential. Therefore, E. uchi bark aqueous extract consumption needs to be approached with caution in therapeutic applications.

Gallic Acid-Based Hydrogels for Phloretin Intestinal Release: A Promising Strategy to Reduce Oxidative Stress in Chronic Diabetes

Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia caused by abnormalities in insulin secretion and/or action. In patients with diabetes, complications such as blindness, delayed wound healing, erectile dysfunction, renal failure, heart disease, etc., are generally related to an increase in ROS levels which, when activated, trigger hyperglycemia-induced lesions, inflammation and insulin resistance. In fact, extensive cell damage and death occurs mainly due to the effect that ROS exerts at the level of cellular constituents, causing the deterioration of DNA and peroxidation of proteins and lipids. Furthermore, elevated levels of reactive oxygen species (ROS) and an imbalance of redox levels in diabetic patients produce insulin resistance. These destructive effects can be controlled by the defense network of antioxidants of natural origin such as phloretin and gallic acid. For this reason, the objective of this work was to create a nanocarrier (hydrogel) based on gallic acid containing phloretin to increase the antioxidant effect of the two substances which function as fundamental for reducing the mechanisms linked to oxidative stress in patients suffering from chronic diabetes. Furthermore, since the bioavailability problems of phloretin at the intestinal level are known, this carrier could facilitate its release and absorption. The obtained hydrogel was characterized using Fourier transform infrared spectroscopy (FT-IR). Its degree of swelling (a%) and phloretin release were tested under pH conditions simulating the gastric and intestinal environment (1.2, 6.8 and 7.4). The antioxidant activity, inhibiting lipid peroxidation in rat liver microsomal membranes induced in vitro by a free radical source, was evaluated for four hours. All results showed that gallate hydrogel could be applied for releasing intestinal phloretin and reducing the ROS levels.

Mango Peels as an Industrial By-Product: A Sustainable Source of Compounds with Antioxidant, Enzymatic, and Antimicrobial Activity

Plant waste materials are important sources of bioactive compounds with remarkable health-promoting benefits. In particular, industrial by-products such as mango peels are sustainable sources of bioactive substances, with antioxidant, enzymatic, and antimicrobial activity. Appropriate processing is essential to obtain highly bioactive compounds for further use in generating value-added products for the food industry. The objective of the study was to investigate and compare the biological activity of compounds from fresh and dried mango peels obtained by different conventional methods and unconventional extraction methods using supercritical fluids (SFE). The highest total phenolic content (25.0 mg GAE/g DW) and the total content of eight phenolic compounds (829.92 µg/g DW) determined by LC-MS/MS were detected in dried mango peel extract obtained by the Soxhlet process (SE). SFE gave the highest content of proanthocyanidins (0.4 mg PAC/g DW). The ethanolic ultrasonic process (UAE) provided the highest antioxidant activity of the product (82.4%) using DPPH radical scavenging activity and total protein content (2.95 mg protein/g DW). Overall, the dried mango peels were richer in bioactive compounds (caffeic acid, chlorogenic acid, gallic acid, catechin, and hesperidin/neohesperidin), indicating successful preservation during air drying. Furthermore, outstanding polyphenol oxidase, superoxide dismutase (SOD), and lipase activities were detected in mango peel extracts. This is the first study in which remarkable antibacterial activities against the growth of Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Bacillus cereus and Staphylococcus aureus) were evaluated by determining the microbial growth inhibition rate after 12 and 24 h incubation periods for mango peel extracts obtained by different methods. Ethanolic SE and UAE extracts from dried mango peels resulted in the lowest minimum inhibitory concentrations (MIC90) for all bacterial species tested. Mango peels are remarkable waste products that could contribute to the sustainable development of exceptional products with high-added value for various applications, especially as dietary supplements.

Gadolinium-Based Magnetic Resonance Theranostic Agent with Gallic Acid as an Anti-Neuroinflammatory and Antioxidant Agent

Studies in the field have actively pursued the incorporation of diverse biological functionalities into gadolinium-based contrast agents, aiming at the amalgamation of MRI imaging and therapeutic capabilities. In this research, we present the development of Gd-Ga, an anti-neuroinflammatory MR contrast agent strategically designed to target inflammatory mediators for comprehensive imaging diagnosis and targeted lesion treatment. Gd-Ga is a gadolinium complex composed of 1,4,7-tris(carboxymethylaza)cyclododecane-10-azaacetylamide (DO3A) conjugated with gallic acid (3,4,5-trihydroxybenzoic acid). Upon intravenous administration in LPS-induced mouse models, Gd-Ga demonstrated a remarkable three-fold increase in signal-to-noise (SNR) variation compared to Gd-DOTA, particularly evident in both the cortex and hippocampus 30 min post-MR monitoring. In-depth investigations, both in vitro and in vivo, into the anti-neuroinflammatory properties of Gd-Ga revealed significantly reduced protein expression levels of pro-inflammatory mediators compared to the LPS group. The alignment between in silico predictions and phantom studies indicates that Gd-Ga acts as an anti-neuroinflammatory agent by directly binding to MD2. Additionally, the robust antioxidant activity of Gd-Ga was confirmed by its effective scavenging of NO and ROS. Our collective findings emphasize the immense potential of this theranostic complex, where a polyphenol serves as an anti-inflammatory drug, presenting an exceptionally efficient platform for the diagnosis and treatment of neuroinflammation.

Naturally Occurring Xanthones; Biological Activities, Chemical Profiles and In Silico Drug Discovery

Xanthones are widely distributed polyphenols, present commonly in higher plants; Garcinia, Calophyllum, Hypericum, Platonia, Mangifera, Gentiana and Swertia. Xanthone tricyclic scaffold is able to interact with different biological targets, showing antibacterial and cytotoxic effects, as well as potent effects against osteoarthritis, malaria, and cardiovascular diseases. Thus, in this article we focused on pharmacological effects, applications and preclinical studies with the recent updates of xanthon´s isolated compounds from 2017-2020. We found that only α-mangostin, gambogic acid, and mangiferin, have been subjected to preclinical studies with particular emphasis on the development of anticancer, diabetes, antimicrobial and hepatoprotective therapeutics. Molecular docking calculations were performed to predict the binding affinities of xanthone-derived compounds against SARS-CoV-2 M^pro. According to the results, cratoxanthone E and morellic acid demonstrated promising binding affinities towards SARS-CoV-2 M^pro with docking scores of -11.2 and -11.0 kcal/mol, respectively. Binding features manifested the capability of cratoxanthone E and morellic acid to exhibit nine and five hydrogen bonds, respectively, with the key amino acids of the M^pro active site. In conclusion, cratoxanthone E and morellic acid are promising anti-COVID-19 drug candidates that warrant further detailed in vivo experimental estimation and clinical assessment.

The Most Potent Natural Pharmaceuticals, Cosmetics, and Food Ingredients Isolated from Plants with Deep Eutectic Solvents

There is growing interest in reducing the number of synthetic products or additives and replacing them with natural ones. The pharmaceutical, cosmetic, and food industries are especially focused on natural and bioactive chemicals isolated from plants or microorganisms. The main challenge here is to develop efficient and ecological methods for their isolation. According to the strategies and rules of sustainable development and green chemistry, green solvents and environmentally friendly technologies must be used. The application of deep eutectic solvents as efficient and biodegradable solvents seems to be a promising alternative to traditional methods. They are classified as being green and ecological but, most importantly, very efficient extraction media compared to organic solvents. The aim of this review is to present the recent findings on green extraction, as well as the biological activities and the possible applications of natural plant ingredients, namely, phenolics, flavonoids, terpenes, saponins, and some others. This paper thoroughly reviews modern, ecological, and efficient extraction methods with the use of deep eutectic solvents (DESs). The newest findings, as well as the factors influencing the efficiency of extraction, such as water content, and hydrogen bond donor and acceptor types, as well as the extraction systems, are also discussed. New solutions to the major problem of separating DESs from the extract and for solvent recycling are also presented.

The Effect of Ethanol Extract from Mesua ferrea Linn Flower on Alzheimer's Disease and Its Underlying Mechanism

The effects of Mesua ferrea Linn flower (MFE) extract on the pathogenic cascade of Alzheimer's disease (AD) were determined by an in vitro and cell culture model in the search for a potential candidate for the treatment of AD. The 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay exhibited that the MFE extract had antioxidant activities. According to the Ellman and the thioflavin T method's result, the extracts could inhibit acetylcholinesterase and β-amyloid (Aβ) aggregation. Studies on neuroprotection in cell culture found that the MFE extract could reduce the death of human neuroblastoma cells (SH-SY5Y) caused by H₂O₂ and Aβ. Western blot analysis exhibited that the MFE extract alleviated H₂O₂-induced neuronal cell damage by downregulating the pro-apoptotic proteins, including cleaved caspase-3, Bax, and by enhancing the expression of anti-apoptotic markers including MCl₁, BCl_xl, and survivin. Moreover, MFE extract inhibited the expression of APP, presenilin 1, and BACE, and increased the expression of neprilysin. In addition, the MFE extract could enhance scopolamine-induced memory deficit in mice. Overall, results showed that the MFE extract had several modes of action related to the AD pathogenesis cascade, including antioxidants, anti-acetylcholinesterase, anti-Aβ aggregation, and neuroprotection against oxidative stress and Aβ. Therefore, the M. ferrea L. flower might be a possibility for further development as a medication for AD.

Regulation of glucolipid metabolism and gut microbiota by green and black teas in hyperglycemic mice

A high-sugar and -fat diet (HSFD) has become a primary risk factor for diabetes, and dietary intervention shows a substantial effect on the prevention and management of hyperglycemia. In this study, the chemical compositions of the aqueous extracts of stir-fried green tea (GT) and congou black tea (BT) were compared. Moreover, their potential mechanisms and regulatory effects on hepatic glycolipid metabolism and gut microbiota disorders in hyperglycemic mice were further explored. Our results show that GT or BT intervention had a prominent regulatory effect on glycolipid metabolism. Moreover, they could significantly regulate the levels of serum metabolic signatures, the activities of key enzymes in liver glucose metabolism, and the expression of genes or proteins related to glycolipid metabolism via activating the IRS-1-PI3K/AKT-GLUT2 signaling pathway. Significantly, GT or BT administration adjusted the composition and diversity of the gut microbiota, mainly reflecting a significant increase in the abundance of beneficial bacteria (including Allobaculum, Lactobacillus, and Turicibacter) and reducing the abundance of harmful or conditionally pathogenic bacteria (mainly including Clostridiales and Bacteroides). Our results suggest that dietary supplementation with GT or BT could exert a practical anti-diabetic effect. Meanwhile, BT intervention showed a better regulation effect on glycolipid metabolism. This study reveals that GT and BT have excellent potential for developing anti-diabetic food.

Cocrystallization of 5-fluorouracil with gallic acid: A novel 5-fluorouracil cocrystal displaying synergistic anti-tumor activity both in oral and intraperitoneal injection administration

Gallic acid (GA) is a naturally occurring polyphenolic compound exhibiting anti-tumor activity. To clarify the capability of GA in optimizing the in vitro/in vivo properties of the first line anti-tumor drug 5-fluorouracil (5-FU) and achieve synergistically enhanced anti-tumor activity, a novel cocrystal hydrate of 5-FU-GA-H₂O was successfully screened and characterized based on various spectroscopic and experimental analysis including Fourier transform infrared spectroscopy (FT-IR), Raman spectra (Raman), powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), thermogravimetric (TG) and scanning electric microscope (SEM) techniques. The results suggested the existence of hydrogen bonding interactions between C=O group of 5-FU and O-H group of GA. Although the dissolution rate and solubility of 5-FU-GA-H₂O cocrystal were slowed and lowered compared with that of 5-FU, respectively, the membrane permeability was enhanced for cocrystal compared with that of intact 5-FU and physical mixture (PM) of 5-FU and GA. For the cocrystal, the cumulative amount per unit area of permeated 5-FU in the first 10 h was 2.56 and 9.97 times of that of pure 5-FU and PM, respectively, in the case that transmembrane behavior of 5-FU depended on the type of solution from which the powder was dissolved. Meanwhile, improvement on oral bioavailability by co-crystallization was observed; AUC_0-t of cocrystal was 2.78-fold higher than that of 5-FU. Furthermore, the cocrystal displayed a superior cytotoxic activity on 4T1 mouse breast cancer cells compared with pure 5-FU and even the PM. It was confirmed that the cocrystal solution induced higher autophagic flux than those of 5-FU and PM in 4T1 cell, suggesting that autophagy rather than apoptosis mainly mediated cell death. The obvious difference of tumor inhibition activity between PM and cocrystal in intraperitoneal injection administration indicated that some of the interactions formed in the solid cocrystal could retain in solution in some way. Benefiting from synergistic cytotoxicity, drug efficacy in vivo was enhanced through injection administration of solution from which cocrystal was dissolved.

Nutrients, Phytochemicals and In Vitro Disease Prevention of Nephelium hypoleucum Kurz Fruit

Nephelium hypoleucum Kurz is an evergreen tree in the Sapindaceae family, mostly found in the forests of some Southeast Asia countries, especially Thailand. The lack of biological information regarding this tree has led to inappropriate agricultural management, conservation and utilization. Thus, this study aims to examine the nutritional composition, organic acid and phenolic profiles and in vitro health properties through several key enzyme inhibitions against some civilization diseases including Alzheimer's disease (β-secretase (BACE-1), butyrylcholinesterase (BChE) and acetylcholinesterase (AChE)), obesity (lipase), hypertension (angiotensin-converting enzyme (ACE)) and diabetes (dipeptidyl peptidase-IV (DPP-IV), α-amylase and α-glucosidase) on the aril (flesh) part of N. hypoleucum Kurz fruit. The remaining fruit parts including the pericarp (peel) and seed were also assessed as sources of potential phenolics as well as key enzyme inhibitors. As results, carbohydrate (17.18 g) was found to be a major source of energy (74.80 kcal) in the aril (100 g fresh weight), with trace amounts of protein (0.78 g) and fat (0.32 g). The fruit aril also contained high insoluble dietary fiber (5.02 g) and vitamin C (11.56 mg), while potassium (215.82 mg) was detected as the major mineral. Organic acid profile indicated that the aril was rich in citric acid, while the phenolic profile suggested predominant quercetin and kaempferol. Interestingly, high gallic acid contents were detected in both pericarp and seed, with the latter 3.2-fold higher than the former. The seed also possessed the highest total phenolic content (TPC, 149.45 mg gallic acid equivalent/g dry weight), while total anthocyanin content (TAC, 0.21 mg cyanidin-3-O-glucoside equivalent/g dry weight) was only detected in pericarp. High TPC also led to high enzyme inhibitory activities in seed including BACE-1, AChE, BChE, ACE, DPP-IV and α-glucosidase. Interestingly, aril with the highest α-amylase inhibition suggested strong inhibitory distribution, predominantly from quercetin and kaempferol. Lipase inhibitory activities were only detected in the aril and pericarp, suggesting the biological function of these two phenolics and possibly anthocyanins.

Comprehensive Analysis of Antioxidant and Hepatoprotective Properties of Morus nigra L

The framework of this study was a comprehensive investigation of Morus nigra L. extracts, with the aim to establish the correlation between chemical composition and antioxidant/hepatoprotective activity of a series of black mulberry extracts obtained from aerial parts of the plant. Black mulberry leaf (MLEE), bark (MBEE), juice (MJ) and fresh fruit (MFEE) extracts were obtained using the conventional Soxhlet extraction, while the supercritical CO₂ extraction procedure was employed for preparation of the seed oil (MSO). Analysis of the chemical composition was performed using spectrophotometric, HPLC and GC methods. For the evaluation of antioxidant activity, in vitro FRAP and DPPH assays were applied. In Haan strain NMRI mice with streptozotocin-induced oxidative stress, in vivo antioxidant activity and liver tissue integrity were examined. The content of polyphenolic compounds was the highest in MBEE (68.3 ± 0.7 mgGAE/g) with the most abundant compounds being polyphenolic acids, followed by MLEE (23.4 ± 0.5 mgGAE/g) with the flavonoids isoquercetin and rutin being present in a significant amount. An analysis of MSO revealed a high content of γ-linoleic acid. The highest antioxidant activity in vitro (FRAP and DPPH) was observed for MLEE, MBEE and MSO. Beneficial effects were confirmed in vivo, with lower values of hepatosomatic index, potentiation of the activity of the enzymes superoxide dismutase and catalase, a lower rate of lipid peroxidation and reduced positivity for the P450 enzyme in animals treated with MLEE, MBEE and MSO. Black mulberry leaf and bark extracts as well as seed oil exhibited significant antioxidant activity. Apart from the confirmed biological properties of the fruit and leaf extracts, the observed activities of black mulberry seed oil and bark extract imply its importance as a sustainable source of phytochemicals.

Caesalpinia palmeri: First Report on the Phenolic Compounds Profile, Antioxidant and Cytotoxicity Effect

This study aimed to determine the phenolic compounds profile, antioxidant potential and cytotoxicity of extracts and fractions of Caesalpinia palmeri. Methanolic extracts were generated from C. palmeri berries, stems and flowers. The latter was subjected to liquid-liquid partition, obtaining hexane, ethyl acetate and residues fractions. Results showed that the flower extract and ethyl acetate fraction had a larger concentration of phenolic compounds (148.9 and 307.9 mg GAE/g, respectively), being ellagic acid (6233.57 and 19550.08 μg/g, respectively), quercetin-3-β-glycoside (3023.85 and 8952.55 μg/g, respectively) and gallic acid (2212.98 and 8422.34 μg/g, respectively) the most abundant compounds. Flower extract and ethyl acetate fraction also presented the highest antioxidant capacity on all tested methods (DPPH, ABTS, ORAC and FRAP) and low cytotoxicity against ARPE-19 cells (IC₅₀ >170 μg/mL). C. palmeri possessed high antioxidant potential, associated with the presence of phenolic compounds and low cytotoxicity, suggesting that they could represent an option to counter oxidative stress.

Inhibition of Cell Proliferation and Induction of Cell Cycle Arrest in Colon Cancer Cells by Lyophilized Mango (Mangifera indica L.) Pulp Extract

The present study evaluated the antiproliferative capacity and possible cell death mechanisms of lyophilized mango pulp extract (LMPE), applied to human colon cancer cells (SW480) and their metastasis-derived counterparts (SW620). The total phenolic content of LMPE was estimated by the Folin-Ciocalteu method. Three assays were employed to determine its antioxidant capacity: ferric-reducing antioxidant power, oxygen radical absorbance capacity, and 2,2-diphenyl-1-picrylhydrazyl. Furthermore, the antiproliferative activity of LMPE was assessed by sulforhodamine B, clonogenic, and Ki-67 assays. Flow cytometry was employed to examine the cell cycle, production of intracellular reactive oxygen species (ROS), cell-surface phosphatidylserine, and change in mitochondrial membrane potential. LMPE exhibited a high level of total phenolic content and antioxidant activity. The mean maximal inhibitory concentration values of LMPE at 48 h of exposure were 43 and 29 mg/mL for SW480 and SW620, respectively. In the SW480 and SW620 cell lines, LMPE at 50 mg/mL and 48 h of exposure induced an increase in intracellular ROS, cell cycle arrest in the G2/M phase, and probably, apoptotic processes without mitochondrial depolarization. LMPE had an antiproliferative capacity against the human colorectal cancer cell lines SW480 and SW620. These results highlight the chemopreventive potential of LMPE in colorectal cancer treatments.

The Conformations of Isolated Gallic Acid: A Laser-Ablation Rotational Study

The rotational spectrum of laser-ablated gallic acid has been recorded using CP-FTMW spectroscopy. Two rotamers have been detected, and their rotational spectra have been assigned and analyzed to obtain the molecular spectroscopic parameters. The observed rotamers have been unambiguously identified in the light of theoretical computations, based on the comparison of the experimental line intensities and rotational parameters with the rotational constants and electric dipole moments predicted from theoretical calculations. The values of the planar inertial moments confirm that the observed conformers are planar, and their relative stability and population have been determined from relative intensity measurements. The B3LYP-D3/6-311++G(2d,p) level has been shown to be the best method among a series of levels normally used to predict the rotational parameters in rotational spectroscopy. In the observed conformers, the three adjacent OH groups are arranged in a sequential form, and the only difference between them lies in the orientation of the COOH group. Although weak attractive OH···O interactions seem to exist, the analysis of the electron density topology does not show the existence of any critical point corresponding to these interactions.

Recent Advances in Natural Polyphenol Research

Polyphenols are secondary metabolites produced by plants, which contribute to the plant's defense against abiotic stress conditions (e.g., UV radiation and precipitation), the aggression of herbivores, and plant pathogens. Epidemiological studies suggest that long-term consumption of plant polyphenols protects against cardiovascular disease, cancer, osteoporosis, diabetes, and neurodegenerative diseases. Their structural diversity has fascinated and confronted analytical chemists on how to carry out unambiguous identification, exhaustive recovery from plants and organic waste, and define their nutritional and biological potential. The food, cosmetic, and pharmaceutical industries employ polyphenols from fruits and vegetables to produce additives, additional foods, and supplements. In some cases, nanocarriers have been used to protect polyphenols during food processing, to solve the issues related to low water solubility, to transport them to the site of action, and improve their bioavailability. This review summarizes the structure-bioactivity relationships, processing parameters that impact polyphenol stability and bioavailability, the research progress in nanocarrier delivery, and the most innovative methodologies for the exhaustive recovery of polyphenols from plant and agri-waste materials.

Potential Anticancer Activity of Pomegranate (Punica granatum L.) Fruits of Different Color: In Vitro and In Silico Evidence

Pomegranate (PMG; Punica granatum L.) fruits possess a well-balanced nutrient/phytochemical composition, with proven adjuvant benefits in experimental cancer chemotherapy; however, such bioactivity could be affected by PMG's phenogenotype (varietal). Here, the chemical and phytochemical (UPLC-DAD-MS2) composition, antioxidant capacity and anticancer potential [in vitro (MTT assay) and in silico (foodinformatics)] of three PMG fruits of different aryl color [red (cv. Wonderful), pink (cv. Molar de Elche), and white (cv. Indian)] were evaluated. The macro/micronutrient (ascorbic acid, tocols, carotenoids), organic acid (citric/malic), and polyphenol content were changed by PMG's varietal and total antioxidant activity (ABTS, alcoholic > hexane extract) in the order of red > pink > white. However, their in vitro cytotoxicity was the same (IC50 > 200 μg.mL-1) against normal (retinal) and cancer (breast, lung, colorectal) cell lines. Sixteen major phytochemicals were tentatively identified, four of them with a high GI absorption/bioavailability score [Ellagic (pink), vanillic (red), gallic (white) acids, D-(+)-catechin (white)] and three of them with multiple molecular targets [Ellagic (52) > vanillic (32) > gallic (23)] associated with anticancer (at initiation and promotion stages) activity. The anticancer potential of the PMG fruit is phenogenotype-specific, although it could be more effective in nutraceutical formulations (concentrates).

Antibacterial and Antioxidant Properties of Extracts of Yucca Baccata, a Plant of Northwestern Mexico, against Pathogenic Bacteria

Introduction

Bacterial agents and oxidative reactions are involved in health and food preservation issues, and Yucca baccata (Y. baccata) can be a source of compounds with practical applications in both areas, but its investigation remains limited.

Materials and Methods

Butanolic (YBE) and aqueous (YAE) extracts were obtained from the stem of Y. baccata. The total saponin, phenolic, and flavonoid contents were analyzed in the YBE and YAE. The antioxidant capacity of the extracts was determined by the DPPH, TEAC, FRAP, and ORAC assays. Seven Gram-positive and five Gram-negative pathogenic bacteria strains were used to determine the MIC and MBC.

Results

Saponin contents were 30% and 1.81% (w/w) in the YBE and YAE, respectively. The total phenolic and flavonoid contents in the extracts were 29.5 μg GAEmg⁻¹ (2.95%) and 5.58 μg GAEmg⁻¹ (0.56%) in the YBE and 69.92 μg QEmg⁻¹ (7.0%) and 1.65 μg QEmg⁻¹ (0.165%) in the YAE. The antioxidant capacity values of YBE were 29.18 μg TEmg⁻¹, 121.8 μg TEmg⁻¹, 33.41 μg TEmg⁻¹, and 156.84 μg TEmg⁻¹ by the DPPH, TEAC, FRAP, and ORAC assays, respectively. YAE had lower antioxidant values than YBE (P < 0.05). Values of 80 mgmL⁻¹ and 100 mgmL⁻¹ were estimated for MIC and MBC of YBE against the Gram-positive bacteria. Values of 100 mgmL⁻¹ and 120 mgmL⁻¹ for MIC and MBC of YBE were estimated against the Gram-negative bacteria. No MIC and MBC were obtained for YAE.

Conclusion

YBE exhibited higher antioxidant activity than YAE. Apparently, antibacterial properties of the YBE tended to be higher than those of the YAE.

Gallic acid functionalized polylysine for endowing cotton fiber with antibacterial, antioxidant, and drug delivery properties

In recent years, the serious influence of infectious diseases on public health and economy development has raised global awareness of the importance of medical textiles for preventing and curing injuries and diseases. The application of biomass molecules is a feasible and sustainable approach to design multipurpose medical materials. In this work, a novel cotton fiber with antibacterial, antioxidant, and drug delivery properties was prepared using gallic acid functionalized polylysine (GA-PL). GA-PL was synthesized by immobilizing GA onto PL using the carbodiimide coupling method. The content of GA immobilized onto PL was 117.9 mg/g. The as-prepared GA-PL was grafted onto oxidized cotton by means of the Schiff base reaction between the amino groups of GA-PL and the aldehyde groups of oxidized cotton. The content of GA-PL grafted onto cotton fiber was 205.1 mg/g. GA-PL grafted cotton fiber exhibited not only durable antibacterial and antioxidant activities but also good drug loading and releasing properties for acetylsalicylic acid. This work presents a novel, cleaner, and sustainable approach to prepare medical cotton fibers with bioactive and drug delivery properties.

The effects of dragon fruit (Hylocereus polyrhizus) extract on indomethacin-induced stomach ulcer in rats

The aim of this study was to investigate the effects of red dragon fruit (Hylocereus polyrhizus) extract (DFE) on the stomach in ulcer model induced by indomethacin in rats. Effects of DFE were evaluated in indomethacin-induced gastric damage model on Sprague-Dawley rats. Experimental model: all rats were fasted for 24 h. At the end of this period, DFE was administered to the ulcer-induced groups. One hour after this application, a dose of 25 mg/kg of indomethacin was applied by oral gavage to all groups except the HEALTHY and DFE1000 groups. Six hours after indomethacin administration, the rats were euthanized with high-dose anesthesia and the experiment was terminated. Macroscopic and microscopic analyses for investigating ulcerative area, molecular and biochemical analyses for oxidative damages investigation and molecular analyses for the effect mechanism of indomethacin and DFE were conducted on stomach tissues in the study. While oxidative stress-associated markers such as MDA, BAX, and Caspase 3 increased dramatically in the indomethacin group, GSH antioxidant levels decreased. It was observed that these parameters were significantly improved in DFE 500 mg/kg and DFE 1000 mg/kg groups compared to ulcer group, and the results of especially DFE 1000 mg/kg group were similar to famotidine group. We observed that our histopathological findings also supported all our other findings. Dragon fruit extract was protected against indomethacin-induced ulcer damage by decreased MDA levels, increased GSH levels, and inhibition of Caspase 3, BAX, and Cox-2, and activation of Cox-1. PRACTICAL APPLICATIONS: People of all ages around the world suffer from gastric ulcer which is one of the most common gastrointestinal ailments. The etiological factors of the disease are using of cigarette and alcohol, nutritional deficiencies, infections, and using non-steroidal anti-inflammatory drugs which use frequent and indiscriminate. Indomethacin is one of the NSAIDs and is commonly preferred to induce ulcer modeling in rats due to its gastric toxicity potential. Current anti-ulcer drugs have many serious side effects. Patients who suffered from gastric ulcer tend to discontinue the drug because of side effects. Therefore, patients need new agents that are non-toxic, have few side effects, and are easily accessible anti-ulcer drugs. Dragon fruit, as a medicinal herb, is highly valuable and widely used in traditional medicine, and may provide gastroprotective activity. Studies have shown that H. polyrhizus has antioxidant activities. We consider the effects of dragon fruit extract (DFE) to be a therapeutic drug for an indomethacin-induced ulcer model.

The Isopropyl Gallate Counteracts Cyclophosphamide-Induced Hemorrhagic Cystitis in Mice

Simple Summary

Ifosfamide (IFOS) is an antineoplastic drug used to treat various cancers. Hemorrhagic cystitis (HC) is the main adverse effect related to the use of IFOS. Acrolein, a metabolite of IFOS, is the main molecule responsible for this side-effect, resulting in increased oxidative stress and production of inflammatory mediators, which culminate in the degradation of bladder tissue. In clinical practice, mesna is used to reduce the incidence of HC. However, this drug presents some dose-dependent side effects. Isopropyl gallate (IPG), a gallic acid-derived compound, is promising for the development of new anti-inflammatory agents. In the present study, the effects of oral administration of IPG against IFOS-induced hemorrhagic cystitis in mice were investigated. Interestingly pretreatment of IPG was able to reduce IFOS-induced bladder damage evidenced by a decrease of inflammatory parameters and improvement in histology and antioxidants of the urinary bladder. Furthermore, IPG significantly decreased the expression levels of inflammatory biomarkers in the bladder tissue. These preliminary findings suggest that IPG represents a promising adjuvant therapy for protecting against IFOS-induced urotoxicity.

Abstract

Hemorrhagic cystitis is the main adverse effect associated with the clinical use of oxazaphosphorine, resulting in increased oxidative stress and proinflammatory cytokines, which culminate in injury of the bladder tissue. The aim of this study was to evaluate the protective effect of isopropyl gallate (IPG) against ifosfamide (IFOS)-induced hemorrhagic cystitis in mice. The induction of the hemorrhagic cystitis model was carried out using a single dose of IFOS (400 mg/kg, i.p.) four hours after oral pretreatment with IPG (6.25, 12.5, 25, and 50 mg/kg) or saline (vehicle). Mesna (positive control; 80 mg/kg, i.p.) was administered four hours before and eight hours after induction of cystitis. In the present study, IPG 25 mg/kg significantly decreased edema and hemorrhage, with a reduction of the bladder wet weight (36.86%), hemoglobin content (54.55%), and peritoneal vascular permeability (42.94%) in urinary bladders of mice. Interestingly, IPG increased SOD activity (89.27%) and reduced MDA levels (35.53%), as well as displayed anti-inflammatory activity by decreasing TNF-α (88.77%), IL-1β (62.87%), and C-reactive protein (56.41%) levels. Our findings demonstrate that IPG has a substantial protective role against IFOS-induced hemorrhagic cystitis in mice by enhancing antioxidant activity and proinflammatory mechanisms. Thus, IPG represents a promising co-adjuvant agent in oxazaphosphorine-based chemotherapy treatments.

Unveiling the Antioxidant Therapeutic Functionality of Sustainable Olive Pomace Active Ingredients

Olive pomace (OP) is the main residue that results from olive oil production. OP is rich in bioactive compounds, including polyphenols, so its use in the treatments of diseases related to oxidative stress, such as cancer, could be considered. The present work aimed to study the biological properties of different OP extracts, obtained by ohmic heating-assisted extraction and conventional heating, using water and 50% ethanol, in the treatment and prevention of colorectal cancer through Caco-2 cell models. Additionally, an in-silico analysis was performed to identify the phenolic intestinal absorption and Caco-2 permeability. The extracts were chemically characterized, and it was found that the Ohmic-hydroethanolic (OH-EtOH) extract had the highest antiproliferative effect, probably due to its higher content of phenolic compounds. The OH-EtOH induced potential modifications in the mitochondrial membrane and led to apoptosis by cell cycle arrest in the G1/S phases with activation of p53 and caspase 3 proteins. In addition, this extract protected the intestine against oxidative stress (ROS) caused by H₂O₂. Therefore, the bioactive compounds present in OP and recovered by applying a green technology such as ohmic-heating, show promising potential to be used in food, nutraceutical, and biomedical applications, reducing this waste and facilitating the circular economy.

Mango "Ataulfo" Peel Extract Improves Metabolic Dysregulation in Prediabetic Wistar Rats

The hypoglycemic effect of functional phytochemicals has been evaluated in diabetic rodents but scarcely in its premorbid condition (prediabetes; PD). This study aimed to evaluate a mango (cv. Ataulfo) peel hydroethanolic (20:80) extract (MPE) for in vivo glycemic/lipidemic-normalizing effect and in vitro enzyme inhibitory (α-amylase/α-glucosidase) activity. The polyphenolic MPE (138 mg EAG.g−1, mainly gallic acid and mangiferin) with antioxidant capacity (DPPH• 34 mgTE.g−1) was fed to PD rats (induction: high-fat diet (60% energy) + single dose streptozotocin (35 mg·kg−1), 4 weeks). At the 8th week, fasting glycemia (FG), oral glucose tolerance test, and insulin sensitivity indexes (HOMA-IR, HOMA-β) > blood lipid-normalizing effect were documented as healthy controls > MPE > disease (PD) controls, which was possibly related to the extract’s concentration−response in vitro enzyme inhibitory activity (IC50 ≈ 0.085 mg·mL−1). MPE is a rich source of glucose-lowering phytochemicals for the primary prevention of type 2 diabetes.

In Vitro Evaluation of Biological Activities and Phytochemical Analysis of Different Solvent Extracts of Punica granatum L. (Pomegranate) Peels

Antimicrobial resistance is a public health concern resulting in high rates of morbidity and mortality worldwide. Furthermore, a high incidence of food poisoning diseases besides harmful implications of applying synthetic food additives in food preservation necessitates fabrication of safe food preservatives. Additionally, damaging effects of free radicals on human health has been reported to be involved in the incidence of serious diseases, including cancer, diabetes and cardiovascular diseases; hence, finding safe sources of antioxidants is vital. Therefore, the present study was carried out to assess the antibacterial, antiradical and carcinopreventive efficacy of different solvent extracts of pomegranate peels. Agar disk diffusion assay revealed that Staphylococcus aureus, MRSA, E. coli and S. typhimurium were highly susceptible to methanolic fraction of Punica granatum L. peels recording inhibition zones of 23.7, 21.8, 15.6 and 14.7 mm respectively. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the methanolic fraction of Punica granatum L. peels against S. aureus were 0.125 and 0.250 mg/mL, respectively. In addition, the pomegranate acetonic and methanolic fractions revealed an impressive antiradical efficiency against DPPH (2,2-diphenyl-1-picrylhydrazyl) radical recording radical scavenging activity percentages of 86.9 and 79.4%, respectively. In this regard, the acetonic fraction of pomegranate peels revealed the highest anti-proliferative efficiency after 48 h incubation against MCF7 cancer cells recording IC₅₀ of 8.15 µg/mL, while the methanolic extract was highly selective against transformed cancer cells compared to normal cell line recording selectivity index of 5.93. GC-MS results demonstrated that 5-Hydroxymethylfurfural was the main active component of methanolic and acetonic extracts of pomegranate peels recording relative percentages of 37.55 and 28.84% respectively. The study recommends application of pomegranate peel extracts in the biofabrication of safe food preservatives, antioxidants and carcinopreventive agents.

Gallic Acid and Diabetes Mellitus: Its Association with Oxidative Stress

Diabetes mellitus (DM) is a severe chronic metabolic disease with increased mortality and morbidity. The pathological progression of DM is intimately connected with the formation and activation of oxidative stress (OS). Especially, the involvement of OS with hyperglycemia, insulin resistance, and inflammation has shown a vital role in the pathophysiological development of DM and related complications. Interestingly, accumulating studies have focused on the exploration of natural antioxidants for their improvement on DM. Of specific interest is gallic acid (GA), which is rich in many edible and herbal plants and has progressively demonstrated robust antioxidative and anti-inflammatory effects on metabolic disorders. To provide a better understanding of its potential therapeutic impacts and enhancement of human health care, the available research evidence supporting the effective antidiabetic properties of GA and relevant derivatives are needed to be summarized and discussed, with emphasis on its regulation on OS and inflammation against DM. This review aims to highlight the latest viewpoints and current research information on the role of OS in diabetes and to provide scientific support for GA as a potential antihypoglycemic agent for DM and its complications.

Cryo-Ground Mango Kernel Powder: Characterization, LC-MS/MS Profiling, Purification of Antioxidant-Rich Gallic Acid, and Molecular Docking Study of Its Major Polyphenols as Potential Inhibitors against SARS-CoV-2 Mpro

Mango processing waste (MPW) is an inexpensive and rich source of valuable substances. Hence, the mango kernel powder (MKP) from four cultivars (Chausa, Neelum, Barahmasi, and Dashehari) was characterized for the selection of the best cultivar. The MKP of the best cultivar (Dashehari) was analyzed for the profiling of polyphenols using LC-MS/MS in both modes of ionization (positive and negative) and indicated the presence of 50 compounds with specific retention times. After identification, gallic acid (GA), an important industrial compound, was targeted and purified followed by its confirmation using NMR (600 MHz) and HRMS. The antioxidant activity (IC50: 1.96 μg/mL) of extracted GA proposes its use as a natural antioxidant in novel food formulations. Additionally, SARS-CoV-2 main protease (Mpro) was selected for molecular docking based virtual screening of seven major polyphenols (MKP), and the results were compared with hydroxychloroquine. The docking scores of targeted polyphenols revealed that three compounds (epicatechin, mangiferin, and quercetin) exhibited appreciable proteolytic activity against Mpro. In this way, it is a favorable approach toward environmental safety on the standpoint of green chemistry owing to the use of food processing waste and elimination of the waste dumping/composting problems.

Analysis of Phytonutrients, Anti-Mutagenic and Chemopreventive Effects of Tropical Fruit Extracts

Thailand is located in the tropics and a wide variety of fruits are grown commercially. However, studies regarding the phytonutrients, anti-mutagenic and chemopreventive effects of these fruits are limited. Thus, phytochemical profiles and inhibition of key enzymes involved in obesity and diabetes, together with anti-mutagenic and chemopreventive properties of eight tropical fruit extracts cultivated in Thailand, including Psidium guajava 'Kimju', Psidium guajava 'Keenok', Ananas comosus 'Pattavia', Ananas comosus 'Phulae', Durio zibethinus 'Chanee', Durio zibethinus 'Monthong', Carica papaya 'Khaekdum' and Mangifera indica 'Namdokmai' were investigated. Different cultivars were also compared. Results showed that M. indica 'Namdokmai' was the most antioxidant-rich extract containing abundant 4-hydroxybenzoic acid and its derivative, gallic acid, as the main phenolics. M. indica 'Namdokmai' also exhibited high inhibitory capacities (>60% inhibition under studied conditions) against lipase, α-amylase and α-glucosidase, key enzymes as drug targets for controlling obesity and type 2 diabetes. Interestingly, all fruit extracts suppressed food mutagen-induced DNA mutations assayed by the Ames test, especially M. indica 'Namdokmai' and C. papaya 'Khaekdum' (>50% inhibition at 200 µg/plate). The M. indica 'Namdokmai' was also the most potent extract for suppression of cancer promotion (>90% inhibition at 200 µg/mL) followed by P. guajava 'Kimju', P. guajava 'Keenok' and C. papaya 'Khaekdum'. Results potentially indicated that fruit intake after overcooked meat consumption might supplement nutrients and fiber and also reduce DNA mutation sources.

Gallic acid for cancer therapy: Molecular mechanisms and boosting efficacy by nanoscopical delivery

Cancer is the second leading cause of death worldwide. Majority of recent research efforts in the field aim to address why cancer resistance to therapy develops and how to overcome or prevent it. In line with this, novel anti-cancer compounds are desperately needed for chemoresistant cancer cells. Phytochemicals, in view of their pharmacological activities and capacity to target various molecular pathways, are of great interest in the development of therapeutics against cancer. Plant-derived-natural products have poor bioavailability which restricts their anti-tumor activity. Gallic acid (GA) is a phenolic acid exclusively found in natural sources such as gallnut, sumac, tea leaves, and oak bark. In this review, we report on the most recent research related to anti-tumor activities of GA in various cancers with a focus on its underlying molecular mechanisms and cellular pathwaysthat that lead to apoptosis and migration of cancer cells. GA down-regulates the expression of molecular pathways involved in cancer progression such as PI3K/Akt. The co-administration of GA with chemotherapeutic agents shows improvements in suppressing cancer malignancy. Various nano-vehicles such as organic- and inorganic nano-materials have been developed for targeted delivery of GA at the tumor site. Here, we suggest that nano-vehicles improve GA bioavailability and its ability for tumor suppression.

Mangifera indica (Mango): A Promising Medicinal Plant for Breast Cancer Therapy and Understanding Its Potential Mechanisms of Action

Globally, breast cancer is the most common cancer type and is one of the most significant causes of deaths in women. To date, multiple clinical interventions have been applied, including surgical resection, radiotherapy, endocrine therapy, targeted therapy and chemotherapy. However, 1) the lack of therapeutic options for metastatic breast cancer, 2) resistance to drug therapy and 3) the lack of more selective therapy for triple-negative breast cancer are some of the major challenges in tackling breast cancer. Given the safe nature of natural products, numerous studies have focused on their anti-cancer potentials. Mangifera indica, commonly known as mango, represents one of the most extensively investigated natural sources. In this review, we provide a comprehensive overview of M. indica extracts (bark, kernel, leaves, peel and pulp) and phytochemicals (mangiferin, norathyriol, gallotannins, gallic acid, pyrogallol, methyl gallate and quercetin) reported for in vitro and in vivo anti-breast cancer activities and their underlying mechanisms based on relevant literature from several scientific databases, including PubMed, Scopus and Google Scholar till date. Overall, the in vitro findings suggest that M. indica extracts and/or phytochemicals inhibit breast cancer cell growth, proliferation, migration and invasion as well as trigger apoptosis and cell cycle arrest. In vivo results demonstrated that there was a reduction in breast tumor xenograft growth. Several potential mechanisms underlying the anti-breast cancer activities have been reported, which include modulation of oxidative status, receptors, signalling pathways, miRNA expression, enzymes and cell cycle regulators. To further explore this medicinal plant against breast cancer, future research directions are addressed. The outcomes of the review revealed that M. indica extracts and their phytochemicals may have potential benefits in the management of breast cancer in women. However, to validate its utility in the creation of innovative and potent therapeutic agents to treat breast cancer, more dedicated research, especially clinical studies are needed to explore the anti-breast cancer potentials of M. indica extracts and their phytochemicals.

Influence of extrusion process on the release of phenolic compounds from mango (Mangifera indica L.) bagasse-added confections and evaluation of their bioaccessibility, intestinal permeability, and antioxidant capacity

Extruded polyphenol-rich by-products like mango bagasse (MB) could be used to manufacture functional confections. However, few reports have assessed the extrusion impact on MB polyphenols within a food matrix. This research aimed to evaluate the impact of extrusion on the bioaccessibility, intestinal permeability, and antioxidant capacity of phenolic compounds (PC) from non-extruded and extruded MB-added confections (EMBC and MBC, respectively). The inhibition of 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl radicals and in silico approaches were used to evaluate the antioxidant capacity. MBC displayed the highest gastric bioaccessibility (%) of xanthones and flavonoids, whereas selective release of gallic acid, mangiferin, and quercetin glucoside was shown for EMBC. Lower PC' apparent permeability coefficients were found in EMBC compared to MB (0.11 to 0.44-fold change, p < 0.05). EMBC displayed the highest antioxidant capacity by the DPPH method for the non-digestible fraction, being mangiferin the highest in silico contributor (-4 kcal/mol). Our results showed that the extrusion process helps release selective phenolics from MBC, which increases their bioaccessibility and intestinal permeability.

Polygonum odoratum leaf extract attenuates oxidative stress and cell death of Raw 264.7 cells exposed to low dose ionizing radiation

This study aims to investigate the effect of Polygonum odoratum leaf extract (POE) on oxidative stress markers and cell death induced by low dose ionizing radiation (LDIR) in Raw 264.7 cells. The biological activities, chromatographic fingerprint, and cytotoxicity of POE were investigated. To determine the radioprotective effect of POE, Raw 264.7 cells were incubated with POE for 1 hr prior to 100 mGy x-irradiation. The cell viability, oxidative stress damage marker (malondialdehyde level; MDA), and endogenous antioxidant markers (superoxide dismutase: SOD, catalase: CAT, and glutathione peroxidase: GSH-Px) were also determined. The results showed that POE contained 8 essential substances and exhibited a potent antioxidant without any cytotoxicity. It was found that POE significantly decreased the MDA level and activated cell viability, SOD, CAT, and GSH-Px activities. The results from this study indicate that POE is a potent antioxidant, which can be developed as a radioprotector for diagnostic procedures. PRACTICAL APPLICATIONS: Polygonum odoratum leaf extract (POE) is a potent antioxidant that attenuates oxidative stress and cell death induced by low dose ionizing radiation (LDIR). POE might protect against cell damage from LDIR, particularly in diagnostic radiology procedures. Therefore, the development of functional food containing POE might be beneficial for patients who plan to undergo the diagnostic radiology procedure. The functional food containing POE might prevent stochastic and deterministic effects for these patients.

Toxic Feedback Loop Involving Iron, Reactive Oxygen Species, α-Synuclein and Neuromelanin in Parkinson's Disease and Intervention with Turmeric

Parkinson's disease (PD) is a movement disorder associated with severe loss of mainly dopaminergic neurons in the substantia nigra. Pathological hallmarks include Lewy bodies, and loss of neuromelanin, due to degeneration of neuromelanin-containing dopaminergic neurons. Despite being described over 200 years ago, the etiology of PD remains unknown. Here, we highlight the roles of reactive oxygen species (ROS), iron, alpha synuclein (α-syn) and neuromelanin in a toxic feedback loop culminating in neuronal death and spread of the disease. Dopaminergic neurons are particularly vulnerable due to decreased antioxidant concentration with aging, constant exposure to ROS and presence of neurotoxic compounds (e.g. ortho-quinones). ROS and iron increase each other's levels, creating a state of oxidative stress. α-Syn aggregation is influenced by ROS and iron but also increases ROS and iron via its induced mitochondrial dysfunction and ferric-reductase activity. Neuromelanin's binding affinity is affected by increased ROS and iron. Furthermore, during neuronal death, neuromelanin is degraded in the extracellular space, releasing its bound toxins. This cycle of events continues to neighboring neurons in the form of a toxic loop, causing PD pathology. The increase in ROS and iron may be an important target for therapies to disrupt this toxic loop, and therefore diets rich in certain 'nutraceuticals' may be beneficial. Turmeric is an attractive candidate, as it is known to have anti-oxidant and iron chelating properties. More studies are needed to test this theory and if validated, this would be a step towards development of lifestyle-based therapeutic modalities to complement existing PD treatments.

Phenolic-Rich Extracts from Avocado Fruit Residues as Functional Food Ingredients with Antioxidant and Antiproliferative Properties

In this study, the total phenolic compounds content and profile, the nutritional value, the antioxidant and antiproliferative activities of avocado peel, seed coat, and seed extracts were characterized. Additionally, an in-silico analysis was performed to identify the phenolic compounds with the highest intestinal absorption and Caco-2 permeability. The avocado peel extract possessed the highest content of phenolic compounds (309.95 ± 25.33 mMol GA/100 g of extract) and the lowest effective concentration (EC₅₀) against DPPH and ABTS radicals (72.64 ± 10.70 and 181.68 ± 18.47, respectively). On the other hand, the peel and seed coat extracts had the lowest energy densities (226.06 ± 0.06 kcal/100 g and 219.62 ± 0.49 kcal/100 g, respectively). Regarding the antiproliferative activity, the avocado peel extract (180 ± 40 µg/mL) showed the lowest inhibitory concentration (IC₅₀), followed by the seed (200 ± 21 µg/mL) and seed coat (340 ± 32 µg/mL) extracts. The IC₅₀ of the extracts induced apoptosis in Caco-2 cells at the early and late stages. According to the in-silico analysis, these results could be related to the higher Caco-2 permeability to hydroxysalidroside, salidroside, sakuranetin, and luteolin. Therefore, this study provides new insights regarding the potential use of these extracts as functional ingredients with antioxidant and antiproliferative properties and as medicinal agents in diseases related to oxidative stress such as cancer.

Ultrasound-microwave-assisted extraction of polyphenolic compounds from Mexican "Ataulfo" mango peels: Antioxidant potential and identification by HPLC/ESI/MS

INTRODUCTION

Mango is used in traditional medicine in many countries. However, the processing by-products are not currently used and generate large pollution problems and high handling costs.

OBJECTIVE

To study the effect of different parameters in the extraction of polyphenolic compounds from mango peels using modern and ecological ultrasound-microwave-assisted extraction technology.

METHODOLOGY

Various parameters of these processes were studied: the extract was recovered by liquid chromatography using Ambetlite XAD-16. The total polyphenol content was determined by Folin-Ciocalteu's and HCl-butanol methods. Antioxidant activity was determined by 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS+), 1,10-diphenyl-2-20-picrylhydrazyl (DPPH), and lipid oxidation inhibition methods. The recovered compounds were identified by high-performance liquid chromatography-mass spectrometry (HPLC-MS).

RESULTS

The best extraction conditions were solid/liquid ratio of 1/5 g/mL, ethanol percentage of 50%, and an extraction time of 10 min. Under these conditions, the total polyphenol content was 54.15 mg/g, and the antioxidant activities were greater than 90% inhibition in the three assays evaluated. According to the high-performance liquid chromatography/electrospray ionization/mass spectrometry (HPLC/ESI/MS) analysis, nine polyphenolic compounds were identified; most of them were gallotannins, such as pentagalloyl glucose.

CONCLUSION

Ultrasound-microwave-assisted extraction was shown to be effective and allowed the recovery of antioxidant polyphenolic compounds. The results indicated that mango peel extracts can be used as natural antioxidant components in the pharmaceutical and functional food industries.

Effect of Ultrasound-Assisted Extraction Parameters on Total Polyphenols and Its Antioxidant Activity from Mango Residues (Mangifera indica L. var. Manililla)

Manililla is a mango variety whose residues contain bioactive compounds such as polyphenols and flavonoids, with high added value. The use of environmentally friendly extraction technology would be of great relevance; hence, this study aimed to evaluate the effect of solvent relation, sonication time and amplitude on the ultrasound-assisted extraction of total polyphenols in Manililla mango residues (peel, endocarp and kernel) and antioxidant activity. An experimental design 23 with a central point was used to evaluate the curvature behavior of the process variables. Conventional maceration was used as a control. The better conditions were obtained at the central point using 50% ethanol in water, 60% amplitude and 20 min of sonication time. We obtained values of up to 1814 mg GAE/100 g, 469 mg GAE/100 g and 672 mg GAE/100 g of total polyphenols and 1228 mg QE/100 g, 653 mg QE/100 g and 880 mg QE/100 g of total flavonoids for peel, endocarp and kernel, respectively. Mangiferin was quantified in ultrasound-assisted extraction at 150 mg/g in peel and 0.025 mg/g in the kernel, but it was not detectable in maceration. An antioxidant capacity of 87%, 14% and 83% inhibition for peel, endocarp and kernel, respectively, were obtained. Peel and kernel were the residues with higher potential as extraction material, while endocarp was not.

Mango (Mangifera indica L.) Polyphenols: Anti-Inflammatory Intestinal Microbial Health Benefits, and Associated Mechanisms of Actions

Mango is rich in polyphenols including gallotannins and gallic acid, among others. The bioavailability of mango polyphenols, especially polymeric gallotannins, is largely dependent on the intestinal microbiota, where the generation of absorbable metabolites depends on microbial enzymes. Mango polyphenols can favorably modulate bacteria associated with the production of bioactive gallotannin metabolites including Lactobacillus plantarum, resulting in intestinal health benefits. In several studies, the prebiotic effects of mango polyphenols and dietary fiber, their potential contribution to lower intestinal inflammation and promotion of intestinal integrity have been demonstrated. Additionally, polyphenols occurring in mango have some potential to interact with intestinal and less likely with hepatic enzymes or transporter systems. This review provides an overview of interactions of mango polyphenols with the intestinal microbiome, associated health benefits and underlying mechanisms.

Quality, Bioactive Compounds, Antioxidant Capacity, and Enzymes of Raspberries at Different Maturity Stages, Effects of Organic vs. Conventional Fertilization

Raspberries are important sources of bioactive compounds, whose synthesis is influenced by the fertilization system and the maturity stage. This study evaluated the effect of organic and conventional fertilization systems on raspberries at three maturity stages, pink, ripe, and overripe. Physicochemical characteristics, bioactive compounds (phenolic profile, vitamin C), antioxidant capacity (DPPH, FRAP, TEAC, and ORAC), phenolic-associated enzyme, phenylalanine ammonia lyase (PAL), and antioxidant enzymes (SOD, CAT, GPx, and APX) were evaluated. The physicochemical determination of the fruit did not reveal differences between fertilization systems. Regarding bioactive compounds, higher content of anthocyanins was found in organic raspberries at all maturity stages. Organic fertilization increased the content of ellagic acid and gallic acid at all stages of maturity. Higher content of caffeic, hydroxybenzoic, protocatechuic acid, and vitamin C was observed in organic raspberry at the overripe stage. Raspberries grown with organic fertilization exhibited higher values of antioxidant capacity by the DPPH, FRAP, and TEAC methods at all maturity stages. Raspberries under organic fertilization showed significantly greater activity of CAT, SOD, APX, GPX, and PAL. The present study suggests that organic fertilization induces oxidative stress causing an increase in antioxidant defense mechanisms, enhancing bioactive compound production, and improving antioxidant capacity in raspberries.

Polyphenols from food by-products: An alternative or complementary therapy to IBD conventional treatments

Inflammatory bowel diseases (IBD) are illnesses characterized by chronic intestinal inflammation and microbial dysbiosis that have emerged as a public health challenge worldwide. It comprises two main conditions: Crohn's disease and ulcerative colitis. Currently, conventional therapy to treat IBD are not free from side effects, such as liver and kidney toxicity, drug resistance, and allergic reactions. In view of this, there is growing research for alternative and complementary therapies that, in addition to acting in the prevention or the control of the disease, do not compromise the quality of life and health of individuals. In this sense, a growing body of evidence has confirmed the benefits of natural phenolic compounds in intestinal health. Phenolic compounds or polyphenols are molecules widely distributed throughout the plant kingdom (flowers, vegetables, leaves, and fruits), including plant materials remaining of the handling and food industrial processing, referred to in the scientific literature as by-products, food waste, or bagasse. Since by-products are low-cost, abundant, easily accessible, safe, and rich in bioactive compounds, it becomes an exciting option to extract, concentrate or isolate phenolic compounds to be posteriorly applied in the therapeutic approach of IBD. In this article, we have reviewed the main phenolic compounds present in various plants and by-products that have shown beneficial and/or promising effects in experimental pre-clinical, clinical, and in vitro research with IBD. In addition, we have mentioned and suggested several plants and by-products originated and produced in Latin America that could be part of future research as good sources of specific phenolic compounds to be applied in the prevention and development of alternative treatments for IBD. This review may offer a valuable reference for studies related to IBD administering phenolic compounds from natural, cheap, and easily accessible raw and undervalued materials.

Comparison of Two Schizophyllum commune Strains in Production of Acetylcholinesterase Inhibitors and Antioxidants from Submerged Cultivation

In recent years, fungi have been recognized as producers of acetylcholinesterase (AChE) inhibitors, agents important for the prevention of Alzheimer’s disease (AD). This study aimed to examine the AChE inhibitory, the antioxidative and antibacterial activity of two different Schizophyllum commune strains that originated from Serbia (SRB) and Italy (IT). Submerged cultivation of grown mycelia (M) and fermentation broth (F) of ethanol (EtOH) and polysaccharide (PSH) extracts lasted for 7, 14, 21 and 28 days. For AChE activity Ellman method was performed, while for antioxidative activity, sevendifferent assays were conducted: DPPH, ABTS, FRAP, SOA, OH, NO together with total phenolic content. Antimicrobial screen, LC–MS/MS technique and FTIR measurements were performed. Different isolates exhibited different AChE activity, with PSH being the strongest (SRB, M, 28 days IC₉₀ 79.73 ± 26.34 µg/mL), while in EtOH extracts, IT stood out (F, 14 days, IC₅₀ 0.8 ± 0.6 µg/mL). PSH extracts (7 days) exhibit significant antioxidative activity (AO), opposite to EtOH extracts where 14 and 21days periods stood out. Only tw extracts showed antibacterial activity. Following LC–MS/MS analysis p-hydroxybenzoic and gallic acids were the most abundant phenolics. PSH extracts demonstrated remarkable results, making this study debut and introducing S. commune as a valuable resource of AChE inhibitors.

Neuroprotective effects of mango cv. 'Ataulfo' peel and pulp against oxidative stress in streptozotocin-induced diabetic rats

BACKGROUND

Oxidative stress has been implicated in the pathogenesis and progression of diabetes mellitus. Both can damage the brain. Mango and its by-products are sources of bioactive compounds with antioxidant properties. We hypothesized that mango cv. 'Ataulfo' peel and pulp mitigate oxidative stress in the brain of streptozotocin-induced diabetic rats.

RESULTS

Twenty-four male Wistar rats were divided into four groups: control, untreated diabetic (UD), diabetic treated with a mango-supplemented diet (MTD), and diabetic pretreated with a mango-supplemented diet (MPD). The rats were fed the different diets for 4 weeks after diabetes induction (MTD), or 2 weeks before and 4 weeks after induction (MPD). After the intervention, serum and brain (cerebellum and cortex) were collected to evaluate gene expression, enzyme activity, and redox biomarkers. Superoxide dismutase 2 (SOD2) expression increased in the cortex of the MTD group, whereas glutathione-S-transferase p1 (GSTp1) expression was higher in the cortex of the MTD group, and cortex and cerebellum of the MPD group. SOD1 activity was higher in the cerebellum and cortex of all diabetic groups, whereas GST activity increased in the cerebellum and cortex of the MPD group. Lipid peroxidation increased in the cerebellum and cortex of the UD group; however, a mango-supplemented diet prevented this increase in both regions, while also mitigating polyphagia and weight loss, and maintaining stable glycemia in diabetic rats.

CONCLUSION

We propose that mango exerts potent neuroprotective properties against diabetes-induced oxidative stress. It can be an alternative to prevent and treat biochemical alterations caused by diabetes. © 2020 Society of Chemical Industry.

Protective Effect of Lemon Peel Polyphenols on Oxidative Stress-Induced Damage to Human Keratinocyte HaCaT Cells Through Activation of the Nrf2/HO-1 Signaling Pathway

Lemon peel can be used as traditional Chinese medicine. Flavonoids are the most important components in lemon peel, which can be developed as natural medicine without side effects. This study investigated the protective effect of lemon peel polyphenols (LPP) on human keratinocyte HaCaT cells under oxidative stress. The active components of LPP were determined by high performance liquid chromatography. The abilities of LPP to scavenge DPPH and ABTS+ free radicals were studied for detection of antioxidation in vitro. Cell survival rates were determined by MTT assay. The antioxidant enzyme activity and antioxidant index of cells were determined using kit. The mRNA and protein expression of cells were determined by qPCR and western blot. The ability of LPP to scavenge DPPH and ABTS+ free radicals were stronger than those of vitamin C (Vc) at the same concentration. As expected, compared with the normal group of cells, the model group had decreased cell survival, increased lactate dehydrogenase (LDH), decreased levels of superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH), and increased malondialdehyde (MDA) content. qPCR and western blot results indicated that the expression of Bcl-2-related X protein (Bax), caspases-3, erythroid-derived nuclear factor 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) were decreased and the expression of B-cell lymphoma-2 (Bcl-2) was increased in the model group, compared with the normal group. LPP treatment improved cell survival rate, reduced intracellular LDH and MDA levels, increased intracellular SOD, CAT, GSH levels, down-regulated Bax, caspases-3, Nrf2, HO-1 expression, and up-regulated Bcl-2 expression. Component analyses found that LPP contains gallic acid, neochlorogenic acid, (+)-catechin, caffeic acid, (-)-Catechin gallate, isochlorogenic acid A, rosmarinic acid, and protocatechuic acid. LPP was found to regulate the Nrf2/HO-1 signaling pathway through 8 active substances to protect HaCaT cells against oxidative stress in vitro.