Upcycling mango peels into a functional ingredient by combining fermentation and enzymatic-assisted extraction

This study aims at upcycling mango peels by a sequential application of enzymatic hydrolysis, using Viscozyme and Pectinex at 50 °C for 2 h; and fermentation, using L. plantarum and B. animalis at 48 h for 37 °C. The use of Viscozyme led to a considerable increase in the concentration of galacturonic and glucuronic acids in the unfermented samples (308.96 and 12.97 mg/100 ml higher than control, respectively), whereas the use of Pectinex resulted in higher oligosaccharide solubilization (5.3 % more than control). None of the enzymes influenced microbiological growth. The recovery of gallic acid aglycone increased 17-fold over the control when Pectinex and B. animalis were used. Similarly, the recovery of mangiferin aglycone increased by 60 % after fermentation by either bacteria. The results indicate that this sequential processing strategy might be utilized to extract phenolic aglycones and produce functional ingredients from mango peels.

Targeting TRPV1 and TRPA1: A feasible strategy for natural herbal medicines to combat postoperative ileus

Under physiological or pathological conditions, transient receptor potential (TRP) channel vanilloid type 1 (TRPV1) and TRP ankyrin 1 (TRPA1) possess the ability to detect a vast array of stimuli and execute diverse functions. Interestingly, increasing works have reported that activation of TRPV1 and TRPA1 could also be beneficial for ameliorating postoperative ileus (POI). Increasing research has revealed that the gastrointestinal (GI) tract is rich in TRPV1/TRPA1, which can be stimulated by capsaicin, allicin and other compounds. This activation stimulates a variety of neurotransmitters, leading to increased intestinal motility and providing protective effects against GI injury. POI is the most common emergent complication following abdominal and pelvic surgery, and is characterized by postoperative bowel dysfunction, pain, and inflammatory responses. It is noteworthy that natural herbs are gradually gaining recognition as a potential therapeutic option for POI due to the lack of effective pharmacological interventions. Therefore, the focus of this paper is on the TRPV1/TRPA1 channel, and an analysis and summary of the processes and mechanism by which natural herbs activate TRPV1/TRPA1 to enhance GI motility and relieve pain are provided, which will lay the foundation for the development of natural herb treatments for this disease.

Mango 'criollo' by-products as a source of polyphenols with antioxidant capacity. Ultrasound assisted extraction evaluated by response surface methodology and HPLC-ESI-QTOF-MS/MS characterization

Ultrasound assisted extraction (UAE) was evaluated as a green procedure for the recovery of phenolic compounds with antioxidant capacity from underutilized mango 'criollo' (peel, pulp and seed). Magnetic stirred was performed as conventional extraction. Response surface methodology using a three-factor (% ethanol, amplitude and time) central composite design was used to maximize the extraction for total phenolic compounds (TPC), total flavonoids and antioxidant capacity. The operational conditions to maximize extraction were: peel, 46% ethanol/amplitude 60% (36 µm)/6.5 min; pulp, 25% ethanol/amplitude 75% (45 µm)/30 min; seed 49% ethanol/100% (60 µm) amplitude/20 min. The phenolic composition of the optimized extracts was characterized by HPLC-QTOF-MS/MS and 45 compounds were tentatively identified as xanthones (mangiferin), flavonoids (quercetin), ellagic acid, benzophenones (maclurin), gallate derivatives and gallotannins. UAE increased TPC extraction (33%); interestingly mangiferin extraction increased 53% in peel, similarly, ellagic acid increased up to 2.5 and 4.4 times in peel and seed extracts.

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.

Phytochemicals as regulators of Th17/Treg balance in inflammatory bowel diseases

Inflammatory bowel disease (IBD) is a chronic inflammatory intestinal disorder that is difficult to cure and characterized by periods of relapse. To face the challenges of limited treatment strategies and drawbacks of conventional medications, developing new and promising strategies as well as safe and effective drugs for treatment of IBD has become an urgent demand for clinics. The imbalance of Th17/Treg is a crucial event for the development of IBD, and studies have verified that correcting the imbalance of Th17/Treg is an effective strategy for preventing and treating IBD. Recently, a growing body of studies has indicated that phytochemicals derived from natural products are potent regulators of Th17/Treg, and exert preferable protective benefits against colonic inflammation. In this review, the great potential of anti-colitis agents derived from natural products through targeting Th17/Treg cells and their action mechanisms for the treatment or prevention of IBD in recent research is summarized, which may help further the development of new drugs for IBD treatment.

Posttranslational modifications as therapeutic targets for intestinal disorders

A variety of biological processes are regulated by posttranslational modifications. Posttranslational modifications including phosphorylation, ubiquitination, glycosylation, and proteolytic cleavage, control diverse physiological functions in the gastrointestinal tract. Therefore, a better understanding of their implications in intestinal diseases, including inflammatory bowel disease, irritable bowel syndrome, celiac disease, and colorectal cancer would provide a basis for the identification of novel biomarkers as well as attractive therapeutic targets. Posttranslational modifications can be common denominators, as well as distinct biomarkers, characterizing pathological differences of various intestinal diseases. This review provides experimental evidence that identifies changes in posttranslational modifications from patient samples, primary cells, or cell lines in intestinal disorders, and a summary of carefully selected information on the use of pharmacological modulators of protein modifications as therapeutic options.

Mangiferin activates Nrf2 to attenuate cardiac fibrosis via redistributing glutaminolysis-derived glutamate

Cardiac injury is followed by fibrosis, characterized by myofibroblast activation. Excessive deposition of extracellular matrix (ECM) impairs the plasticity of myocardium and results in myocardial systolic and diastolic dysfunction. Mangiferin is a xanthonoid derivative rich in plants mangoes and iris unguicularis, exhibiting the ability to ameliorate metabolic disorders. This study aims to investigate whether mangiferin attenuates cardiac fibrosis via redox regulation. The transverse aortic constriction (TAC) in mice induced cardiac fibrosis with impaired heart function. Oral administration of mangiferin (50 mg/kg, 4 weeks) inhibited myofibroblast activation with reduced formation of ECM. The impaired left ventricular contractive function was also improved by mangiferin. TGF-β1 stimulation increased glutaminolysis to fuel intracellular glutamate pool for the increased demands of nutrients to support cardiac myofibroblast activation. Mangiferin degraded Keap1 to promote Nrf2 protein accumulation by improving its stability, leading to Nrf2 activation. Nrf2 transcriptionally promotes the synthesis of antioxidant proteins. By activating Nrf2, mangiferin promoted the synthesis of glutathione (GSH) in cardiac fibroblasts, likely due to the consumption of glutaminolysis-derived glutamate as a source. Meanwhile, mangiferin promoted the exchange of intracellular glutamate for the import of extracellular cystine to support GSH generation. As a result of redistribution, the reduced glutamate availability failed to support myofibroblast activation. In support of this, the addition of extracellular glutamate or α-ketoglutarate diminished the inhibitory effects of mangiferin on cardiac myofibroblast proliferation and activation. Moreover, cardiac knockdown of Nrf2 attenuated the cardioprotective effects of mangiferin in mice subjected to TAC. In conclusion, we demonstrated that activated myofibroblasts were sensitive to glutamate availability. Mangiferin activated Nrf2 and redistributed intracellular glutamate for the synthesis of GSH, consequently impairing cardiac myofibroblast activation due to decreased glutamate availability. These results address that pharmacological activation of Nrf2 could restrain cardiac fibrosis via metabolic regulation.

Nose to brain drug delivery - A promising strategy for active components from herbal medicine for treating cerebral ischemia reperfusion

Cerebral ischemia reperfusion injury (CIRI), one of the major causes of death from stroke in the world, not only causes tremendous damage to human health, but also brings heavy economic burden to society. Current available treatments for CIRI, including mechanical therapies and drug therapies, are often accompanied by significant side-effects. Therefore, it is necessary to discovery new strategies for treating CIRI. Many studies have confirmed that the herbal medicine has the advantages of abundant resources, good curative effect and little side effects, which can be used as potential drug for treatment of CIRI through multiple targets. It's known that oral administration commonly has low bioavailability, and injection administration is inconvenient and unsafe. Many drugs can't delivery to brain through routine pathways due to the blood-brain-barrier (BBB). Interestingly, increasing evidences have suggested the nasal administration is a potential direct route to transport drug into brain avoiding the BBB and has the characteristics of high bioavailability for treating brain diseases. Therefore, intranasal administration can be treated as an alternative way to treat brain diseases. In the present review, effective methods to treat CIRI by using active ingredients derived from herbal medicine through nose to brain drug delivery (NBDD) are updated and discussed, and some related pharmacological mechanisms have also been emphasized. Our present study would be beneficial for the further drug development of natural agents from herbal medicines via NBDD.

Potential of benzophenones and flavanones to modulate the bitter intensity of Cyclopia genistoides herbal tea

Variation in the bitter taste of Cyclopia genistoides (honeybush) herbal tea and reported modulation between its major xanthones, mangiferin and isomangiferin, prompted further investigation into the potential modulatory effects of honeybush phenolics. Combinations of crude benzophenone (BF)-, xanthone (XF)-, and flavanone (FF)-rich fractions and their major individual phenolic compounds were analysed by descriptive sensory analysis. The fractions were prepared from a bitter, hot water extract of green C. genistoides. Fraction BF, which is below the bitter threshold (intensity 10 on 100-point scale), enhanced the bitter intensity of XF and FF slightly (p < 0.05), although none of the major individual benzophenones retained this bitter enhancing effect. On the contrary, 3-β-d-glucopyranosyl-4-β-d-glucopyranosyloxyiriflophenone, the major benzophenone in BF, significantly (p < 0.05) decreased the bitter taste of XF, at a low concentration, whereas FF suppressed the bitter intensity of XF and mangiferin, the major xanthone present in XF. Hesperidin, however, had no effect on the bitter intensity of XF. In contrast, (2S)-5-[α-L-rhamnopyranosyl-(1→2)-β-d-glucopyranosyloxy]-naringenin, the major compound of FF, significantly (p < 0.05) enhanced the bitter taste of XF when added at concentrations comparable to that of 'fermented' honeybush tea infusions. The concentration-dependence of these bitter taste interactions may be responsible for the variable bitter intensity of C. genistoides herbal tea.

Food quality and nutraceutical value of nine cultivars of mango (Mangifera indica L.) fruits grown in Mediterranean subtropical environment

Mango (Mangifera indica L.) quality is strongly influenced by genotype but individuating the most appropriate harvesting time is essential to obtain high quality fruits. In this trial we studied the influences of the ripening stage at harvest (mature-ripe or green-ripe) on quality of ready to eat mango fruits from nine cultivars (Carrie, Keitt, Glenn, Manzanillo, Maya, Rosa, Osteen, Tommy Atkins and Kensington Pride) grown in the Mediterranean subtropical climate through physicochemical, nutraceutical, and sensory analysis. Our results show a large variability among the different observed genotypes and in dependence of the ripening stage at harvest. With the exception of Rosa, mature-ripe fruits are well-colored, sweet and aromatic, and better suited for short supply chains. On the other hand, post-harvest ripened fruits are firmer, frequently (Carrie, Glenn, Keitt, Manzanillo, Maya) possess interesting nutraceutical value and, in the case of Glenn, Maya, Osteen, and Kensington Pride, they can reach market standard quality.

Metabolic profiling of four South African herbal teas using high resolution liquid chromatography-mass spectrometry and nuclear magnetic resonance

Increased preference to herbal drinks has led to global interest in the use and production of different plant species for the preparation of various drink formulations. Medicinal properties derived from bioactive compounds remain the main driver of choice for herbal teas. This study determined the chemical variation in honeybush, rooibos, special and bush tea, profiled compounds responsible for such differences and compared their peak areas. Nuclear magnetic resonance and high resolution liquid chromatography-mass spectrometry were used to determine compound variation and profiling. Principal component analysis and partial-least square multivariate statistical analysis showed distinct differences (P < 0.05) between the different types of herbal teas. Detected compounds included flavonoids, phenolics, lignans, megastigmane glycoside, most of which possess health benefits. The findings showed that South African herbal teas could play a vital role as health promoting drinks, and that bush tea and special tea are phytochemically comparable with other commercialized herbal teas.

Levels of terpenoids, mangiferin and phenolic acids in the pulp and peel of ripe mango fruit influenced by pre-harvest spray application of FeSO4 (Fe2+), MgSO4 (Mg2+) and MnSO4 (Mn2+)

Fe²⁺, Mg²⁺ and Mn²⁺ are enzyme cofactors in terpenoids biosynthesis. Effects of pre-harvest spray of FeSO₄, MgSO₄ and MnSO₄ (0.2% and 0.3%) 30 d prior to harvest on the levels of terpenoids and phenolic compounds in ripe mango fruit were investigated. All treatments significantly increased lupeol in the peel compared to control and it was highest in pulp of 0.3% FeSO₄-treated fruit. Spray of each nutrient (0.3%) increased total carotenoids in the pulp. Mangiferin in pulp was significantly higher in the fruit treated with 0.2% FeSO₄, MgSO₄ and MnSO₄ compared to control and 0.3%. Concentrations of gallic, ferulic and caffeic acids in the peel and chlorogenic acid in pulp and peel were highest in fruit sprayed with 0.2% FeSO₄. In conclusion, pre-harvest spray of FeSO₄, MgSO₄ and MnSO₄ regulates concentrations of terpenoids and phenolic compounds in the pulp and peel of ripe mango fruit.

Targeting oncogenic transcription factors by polyphenols: A novel approach for cancer therapy

Inflammation is one of the major causative factor of cancer and chronic inflammation is involved in all the major steps of cancer initiation, progression metastasis and drug resistance. The molecular mechanism of inflammation driven cancer is the complex interplay between oncogenic and tumor suppressive transcription factors which include FOXM1, NF-kB, STAT3, Wnt/β- Catenin, HIF-1α, NRF2, androgen and estrogen receptors. Several products derived from natural sources modulate the expression and activity of multiple transcription factors in various tumor models as evident from studies conducted in cell lines, pre-clinical models and clinical samples. Further combination of these natural products along with currently approved cancer therapies added an additional advantage and they considered as promising targets for prevention and treatment of inflammation and cancer. In this review we discuss the application of multi-targeting natural products by analyzing the literature and future directions for their plausible applications in drug discovery.

Mangiferin protects against ‭intestinal ischemia/reperfusion-induced ‭liver injury: ‬‬Involvement of PPAR-‭γ, GSK-3β and Wnt/β-catenin pathway‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬

AIM

Mangiferin (MF), a xanthonoid from Mangifera indica, possesses anti-inflammatory, immunomodulatory, and potent antioxidant effects; however, its protective effect against mesenteric ischemia/reperfusion (I/R)-induced liver injury has not been fully clarified. The study was designed to assess the possible mechanism of action of MF against mesenteric I/R model.

MAIN METHODS

Male Wister rats were treated with MF (20mg/kg, i.p) or the vehicle for 3 days before I/R, which was induced by clamping the superior mesenteric artery for 30min followed by declamping for 60min.

KEY FINDINGS

The mechanistic studies revealed that MF protected the 2 organs studied, viz., liver and intestine partly via increasing the content of β-catenin and PPAR-γ along with decreasing that of GSK-3β and the phosphorylated NF-қB-p65. MF antioxidant effect was evidenced by increasing contents of total antioxidant capacity and GST, besides normalizing that of MDA. Regarding the anti-inflammatory effect, MF reduced IL-1β and IL-6, effects that were mirrored on the tissue content of MPO. Moreover, MF possessed anti-apoptotic character evidenced by elevating Bcl-2 content and reducing that of caspase-3. In the serum, intestinal I/R increased the activity of ALT, AST, and creatine kinase.

SIGNIFICANCE

The intimated protective mechanisms of MF against mesenteric I/R are mediated, partially, by modulation of oxidative stress, inflammation, and apoptosis possibly via the involvement of Wnt/β-catenin/NF-қβ/ PPAR-γ signaling pathways.

Mangiferin protects mitochondrial function by preserving mitochondrial hexokinase-II in vessel endothelial cells

Hexokinase-II (HK-II) confers protection against cell death and this study was designed to investigate the effect of mangiferin on the regulation of mitochondrial HK-II. In vessel endothelial cells, saturated fatty acid palmitate (PA) stimulation induced HK-II detachment from mitochondria due to cellular acidification. Mangiferin reduced lactate accumulation by improving pyruvate dehydrogenase activity, promoted Akt translocation to HK-II and prevented HK-II detachment from mitochondria. Knockdown of Akt2 diminished the protective effect of mangiferin on mitochondrial HK-II, confirming the role of Akt in the regulation of HK-II. Mangiferin prevented mitochondrial permeability transition pore opening, restored mitochondrial membrane potential and thereby protected cell from apoptosis. In high-fat diet fed mice, oral administration of mangiferin induced Akt phosphorylation, increased HK-II binding to mitochondria and resultantly protected vessel endothelial function, demonstrating its protective effect on endothelial integrity in vivo. This finding provided a novel strategy for the protection of mitochondrial function in the endothelium.

Rhizoma Anemarrhenae extract ameliorates hyperglycemia and insulin resistance via activation of AMP-activated protein kinase in diabetic rodents

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizoma Anemarrhenae has been used in Asian countries for thousands of years to treat diabetes. Insulin resistance (IR) is the primary cause responsible for type 2 diabetes. The aim of this study was to to assess the hypoglycemic and insulin sensitizing properties of Rhizoma Anemarrhenae extract (TFA) in animal models of insulin resistance and/or diabetes and to delineate modes of action.

MATERIALS AND METHODS

In-vivo studies were performed on STZ-induced diabetic mice and KK-Ay mice, the former of which were given the extract alone or in combination with insulin for 7 days, and the latter of which were given the extract for 8 consecutive weeks. Fasting blood glucose and serum insulin levels were measured. Pancreatic tissue sections were examined using transmission electron micrographs. Further, hyperinsulinemic-euglycemic clamping study was conducted in BCG vaccine-induced insulin resistance rats, and glucose infusion rate was examined. Mechanisms of action were investigated in 3T3-L1 and Hela cells using Western blot analysis.

RESULTS

Our study showed that TFA enhanced the glucose-lowering effects of exogenous insulin administration in STZ-induced diabetic mice. Therapeutic administration of TFA significantly reduced fasting blood glucose, and serum insulin levels, and markedly increased the size and the number of insulin-producing beta cells in KK-Ay mice. Further, hyperinsulinemic-euglycemic clamping study showed that glucose infusion rate was significantly improved in TFA-treated BCG vaccine-induced insulin resistance rats. Study of mechanism of action revealed that TFA increased phosphorylation of AMPK and its downstream target, acetyl-CoA carboxylase (ACC) in 3T3-L1 cells. It activates AMPK in a LKB1-independent manner, providing a unified explanation for the beneficial effects of TFA.

CONCLUSIONS

This study that TFA mediates activation of AMPK and improves overall glucose and lipid metabolism in diabetic rodents, highlights the potential utility of TFA for the management of type 2 diabetes.