Anti-diabetic activity in type 2 diabetic mice and α-glucosidase inhibitory, antioxidant and anti-inflammatory potential of chemically profiled pear peel and pulp extracts (Pyrus spp.)

Investigation into Polyphenol Profile and Biological Activities of Enriched Persimmon/Apple Smoothies during Storage

Smoothies are becoming an increasingly popular product as a healthy alternative to snacks. The consumer expects from this product that, apart from its nutritional value, it will also be qualitatively stable during storage. Therefore, in this study, original smoothies obtained with persimmon fruit puree and apple juice (Dk/Md) enriched with Arbutus unedo fruits, Myrtus communis purple berry extract, Acca sellowiana, and Crocus sativus petal juice were evaluated for their polyphenol composition, antioxidant activity, and inhibition on targeted digestive enzymes, over six months of storage. The amount of polyphenols evaluated by UPLC-PDA analysis decreased in six months from 23.5% for both Dk/Md and enriched C. sativus smoothies to 42.5% for enriched A. sellowiana, with anthocyanins the most sensitive compounds (71.7-100% loss). Values of antioxidant assays generally strongly decreased during the first three months (up to ca. 60%) and to a lesser extent in the following three months (0.4-27%). In addition, inhibitory activity on α-amylase, α-glucosidase, and pancreatic lipase, especially on the last two enzymes, was negatively affected by time storage. The outcome of this study indicates that persimmon fruit is a good option for producing smoothies, and enrichment with other plant extracts can enhance the bioactive compound content and biological activities. It is recommended that appropriate storage strategies to preserve the properties of those smoothies should be developed.

Anti-Diabetic Potential of Polyphenol-Rich Fruits from the Maleae Tribe-A Review of In Vitro and In Vivo Animal and Human Trials

The Maleae tribe consists of over one thousand species, including many well-known polyphenol-containing fruit crops with wide-ranging biological properties, e.g., apples (Malus), chokeberries (Aronia), pears (Pyrus), quinces (Cydonia, Chaenomeles), saskatoon (Amelanchier), loquats (Eriobotrya), medlars (Mespilus), rowans (Sorbus), and hawthorns (Crataegus). Considering the current interest in the concept of functional foods and the still-insufficient methods of diabetes management, the anti-diabetic potential of fruits has been studied intensively, including those of the Maleae tribe. This paper is the first comprehensive overview of this selected topic, covering articles published from 2000 to 2023 (131 articles in total). The first part of this review focuses on the potential mechanisms of action of fruits investigated so far (46 species), including their effects on tissue-specific glucose transport and the expression or activity of proteins in the insulin signalling pathway. The second part covers the phytocompounds responsible for particular fruits' activity-primarily polyphenols (e.g., flavonols, dihydrochalcones, proanthocyanidins, anthocyanins, phenolic acids), but also polysaccharides, triterpenes, and their additive and synergistic effects. In summary, fruits from the Maleae tribe seem promising as functional foods and anti-diabetic agents; however, their prospects for more expansive pro-health application require further research, especially more profound in vivo trials.

Eating with peel or not: Investigation of the peel consumption situation and its nutrition, risk analysis, and dietary advice in China

Nutritious, balanced, tasty and easy to eat, fruit is an indispensable health food for consumers. With consumers' increasing respect for the concept of health, green and nutrition, the peel, which has higher nutritional value compared to the pulp, is gradually being emphasized in the consumption process. The suitability of fruit peels for consumption is influenced by various factors, such as the amount of pesticide residues, nutrient content, ease of peeling, and fruit texture, but there is a lack of relevant studies to guide consumers' scientific intake of fruit peels. This review first investigated chineses consumers consumption of common fruits with peels, especially eight fruits that are controversial in terms of whether to consume them with peels, and the results showed that whether people consume peels depends mainly on their nutritional value and pesticide residues. Based on this, the paper discusses the common methods of pesticide detection and removal from fruit peels, as well as the nutrients contained in different fruit peels and their physiological activities, if the peels usually have stronger antioxidant, anti-inflammatory and anti-tumor activities than the pulp. Finally, reasonable dietary recommendations are made on whether fruits should be consumed with their peels, with a view to guiding chineses consumers towards scientific consumption and provide theoretical basis for relevant research in other countries.

Antioxidant Activity and Inhibition of Digestive Enzymes of New Strawberry Tree Fruit/Apple Smoothies

In this study, original smoothies obtained with strawberry tree fruit puree and apple juice enriched with Diospyros kaki fruits, Myrtus communis purple berry extract, Acca sellowiana, and Crocus sativus petal juice were evaluated for their antioxidant activity and inhibition of targeted digestive enzymes. Values of CUPRAC, FRAP, ORAC, DPPH•, and ABTS•+ assays generally increased with plant enrichment, particularly for A. sellowiana addition (ABTS•+ 2.51 ± 0.01 mmol Trolox/100 g fw). The same trend was observed regarding the ability to scavenge reactive oxygen species (ROS) tested in Caco-2 cell cultures. Inhibitory activity on α-amylase and α-glucosidase was increased by D. kaki, M. communis, and A. sellowiana. Total polyphenols evaluated by UPLC-PDA analysis ranged between 535.75 ± 3.11 and 635.96 ± 5.21 mg/100 g fw, and A. sellowiana provided the higher amount. Flavan-3-ols accounted for more than 70% of phenolic compounds, and only smoothies enriched with C. sativus showed a high amount of anthocyanins (25.12 ± 0.18 mg/100 g fw). The outcome of this study indicates these original smoothies as a possible ally in counteracting oxidative stress, as established by their favourable antioxidant compound profile, thus suggesting an interesting future application as nutraceuticals.

A New Bloody Pulp Selection of Myrobalan (Prunus cerasifera L.): Pomological Traits, Chemical Composition, and Nutraceutical Properties

A new accession of myrobalan (Prunus cerasifera L.) from Sicily (Italy) was studied for the first time for its chemical and nutraceutical properties. A description of the main morphological and pomological traits was created as a tool for characterization for consumers. For this purpose, three different extracts of fresh myrobalan fruits were subjected to different analyses, including the evaluation of total phenol (TPC), flavonoid (TFC), and anthocyanin (TAC) contents. The extracts exhibited a TPC in the range 34.52-97.63 mg gallic acid equivalent (GAE)/100 g fresh weight (FW), a TFC of 0.23-0.96 mg quercetin equivalent (QE)/100 g FW, and a TAC of 20.24-55.33 cyanidine-3-O-glucoside/100 g FW. LC-HRMS analysis evidenced that the compounds mainly belong to the flavonols, flavan-3-ols, proanthocyanidins, anthocyanins, hydroxycinnamic acid derivatives, and organic acids classes. A multitarget approach was used to assess the antioxidant properties by using FRAP, ABTS, DPPH, and β-carotene bleaching tests. Moreover, the myrobalan fruit extracts were tested as inhibitors of the key enzymes related to obesity and metabolic syndrome (α-glucosidase, α-amylase, and lipase). All extracts exhibited an ABTS radical scavenging activity that was higher than the positive control BHT (IC₅₀ value in the range 1.19-2.97 μg/mL). Moreover, all extracts showed iron-reducing activity, with a potency similar to that of BHT (53.01-64.90 vs 3.26 μM Fe(II)/g). The PF extract exhibited a promising lipase inhibitory effect (IC₅₀ value of 29.61 μg/mL).

Antioxidant and In Vivo Hypoglycemic Activities of Ethanol Extract from the Leaves of Engelhardia roxburghiana Wall, a Comparative Study of the Extract and Astilbin

The leaves of Engelhardia roxburghiana Wall (LERW) has been used as sweet tea in China throughout history. In this study, the ethanol extract of LERW (E-LERW) was prepared and the compositions were identified by HPLC-MS/MS. It indicates that astilbin was the predominant component in E-LERW. In addition, E-LERW was abundant in polyphenols. Compared to astilbin, E-LERW presented much more powerful antioxidant activity. The E-LERW also had stronger affinity with α-glucosidase and exerted more vigorous inhibitory effect on the enzyme. Alloxan-induced diabetic mice had significantly elevated glucose and lipid levels. Treatment with E-LERW at the medium dose (M) of 300 mg/kg could reduce the levels of glucose, TG, TC, and LDL by 16.64%, 12.87%, 32.70%, and 22.99%, respectively. In addition, E-LERW (M) decreased food intake, water intake, and excretion by 27.29%, 36.15%, and 30.93%, respectively. Moreover, E-LERW (M) therapy increased the mouse weight and insulin secretion by 25.30% and 494.52%. With respect to the astilbin control, E-LERW was more efficient in reducing the food and drink consumption and protecting pancreatic islet and body organs from alloxan-induced damage. The study demonstrates that E-LERW may be a promising functional ingredient for the adjuvant therapy of diabetes.

Role and mechanism of fruit waste polyphenols in diabetes management

Among various diseases in humans, diabetes is one of the most complicated disorders resulting either from the malfunctioning of β cells, causing a poor discharge of insulin from them, or poor functioning of the liberated insulin. A wide array of chemical compounds so-called secondary metabolites are present in plants. These phytochemicals are produced as by-products of metabolism and play a key role in plant protection. However, in humans, they offer several beneficial functions. Polyphenols are an important class of phytochemicals and apart from fruits, they are also found in their major wastes mainly including the peel, pomace, and seed. The current review is aimed to focus on the potential sources, distribution, and extraction/isolation of polyphenols from major fruit wastes along with highlighting their medicinal and therapeutic benefits, especially in the management of diabetes.

A comparison of the mineral element content of 70 different varieties of pear fruit (Pyrus ussuriensis) in China

Background

Pyrus ussuriensis (Maxim.) is a unique pear tree that grows in northern China. The tree has strong cold resistance and can withstand low temperatures from -30 °C to -35 °C. Due to its unique growth environment, its fruit is rich in minerals and has much higher levels of minerals such as K, Ca and Mg than the fruit of Pyrus pyrifolia (Nakai.) and Pyrus bretschneideri (Rehd.) on the market, and many say the ripe fruit tastes better than other varieties. A comprehensive analysis of the characteristics of mineral elements in the fruits of different varieties of P. ussuriensis will provide a valuable scientific basis for the selection, breeding and production of consumer varieties of P. ussuriensis, and provide a more complete understanding of nutritional differences between fruit varieties.

Methods

In this study, 70 varieties of wild, domesticated and cultivated species of P. ussuriensis from different geographical locations were compared. Targeting four main mineral elements and eight trace mineral elements contained in the fruit, the differences in mineral content in the peel and pulp of different varieties of P. ussuriensis were analyzed, compared and classified using modern microwave digestion ICP-MS.

Results

The mineral elements in the fruit of P. ussuriensis generally followed the following content pattern: K > P > Ca > Mg > Na > Al > Fe > Zn > Cu > Cr > Pb > Cd. The mineral element compositions in the peel and pulp of different fruits were also significantly different. The four main mineral elements in the peel were K > Ca > P > Mg, and K > P > Mg > Ca in the pulp. The mineral element content of wild fruit varieties was higher than that of cultivated and domesticated varieties. Correlation analysis results showed that there was a significant positive correlation between K, P and Cu in both the peel and pulp of P. ussuriensis fruit (P < 0. 01). Cluster analysis results showed that the 70 varieties of P. ussuriensis could be divided into three slightly different categories according to the content of the peel or pulp. According to the contents of the fruit peel, these varieties were divided into: (1) varieties with high Na, Mg, P, K, Fe and Zn content, (2) varieties with high Ca content and (3) varieties with medium levels of mineral elements. According to the fruit pulp content, these varieties were divided into: (1) varieties with high Mg, P and K content, (2) varieties with low mineral element content, and (3) varieties with high Na and Ca content. The comprehensive analysis of relevant mineral element content factors showed that 'SSHMSL,' 'QYL,' 'SWSL' and 'ZLTSL-3' were the best varieties, and could be used as the focus varieties of future breeding programs for large-scale pear production.

Antidiabetic effect of sciadonic acid on type 2 diabetic mice through activating the PI3K-AKT signaling pathway and altering intestinal flora

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by hyperglycemia. The aim of this work was to investigate the effect of sciadonic acid (SA) on disorders of glucolipid metabolism and intestinal flora imbalance and to further investigate its potential molecular mechanism of anti-diabetes. The experimental data indicated that SA could alleviate hyperlipidemia, insulin resistance, oxidative stress, the inflammatory response, repair liver function damage, and promote glycogen synthesis caused by T2DM. SA could also activate the PI3K/AKT/GLUT-2 signaling pathway, promote glucose metabolism gene expression, and maintain glucose homeostasis. Furthermore, 16S rRNA analysis revealed that SA could reduce the Firmicutes/Bacteroidota (F/B) ratio; promote norank_f__Muribaculaceae, Allobaculum, Akkermansia, and Eubacterium_siraeum_group proliferation; increase the levels of major short-chain fatty acids (SCFAs), such as acetic acid, propionic acid, and butyric acid; and maintain the homeostasis of the intestinal flora. In conclusion, these results suggested that SA could reshape the structural composition of intestinal microbes, activate the PI3K/AKT/GLUT2 pathway, improve insulin resistance, and decrease blood glucose levels.

Antioxidant and Hypoglycemic Activity of Sequentially Extracted Fractions from Pingguoli Pear Fermentation Broth and Identification of Bioactive Compounds

Pear fruits have been reported to contain abundant bioactive compounds and exhibit antidiabetic activity. In this study, Pingguoli pear (Pyrus pyrifolia cv.‘Pingguoli’) fermentation broth was sequentially extracted by five solvents with increasing polarity (petroleum ether, chloroform, ethyl acetate, n-butanol, and water) to evaluate its antioxidant and hypothermic activities, and then the main compounds of the fraction with the highest activity were assessed, which might be responsible for such activities. The results showed that the ethyl acetate fraction (EAF) exhibited the highest antioxidant activity according to DPPH (IC₅₀ = 0.238 mg/mL), ABTS (IC₅₀ = 0.293 mg/mL), and FRAP (IC₅₀ = 0.193 mg/mL) assays. The in vitro hypoglycemic activity assay showed that EAF exhibited the strongest inhibitory effect, with IC₅₀ values of 0.34 and 0.95 mg/mL for α-amylase and α-glucosidase, respectively. The glucose consumption in HepG2 cells treated with EAF was significantly increased to 252%, compare with control group. Liquid chromatography–mass spectrometry analysis implied that the main compounds, 3′-C-glucosylisoliquiritigenin, robustside D, caffeic acid, and chlorogenic acid may be potential candidates for the antioxidant and hypoglycemic activities of the EAF. This study suggested that EAF of Pingguoli pear fermentation broth could be utilized for development of potential functional food and antidiabetic agents.

Agri-Food Waste from Apple, Pear, and Sugar Beet as a Source of Protective Bioactive Molecules for Endothelial Dysfunction and Its Major Complications

Endothelial damage is recognized as the initial step that precedes several cardiovascular diseases (CVD), such as atherosclerosis, hypertension, and coronary artery disease. It has been demonstrated that the best treatment for CVD is prevention, and, in the frame of a healthy lifestyle, the consumption of vegetables, rich in bioactive molecules, appears effective at reducing the risk of CVD. In this context, the large amount of agri-food industry waste, considered a global problem due to its environmental and economic impact, represents an unexplored source of bioactive compounds. This review provides a summary regarding the possible exploitation of waste or by-products derived by the processing of three traditional Italian crops-apple, pear, and sugar beet-as a source of bioactive molecules to protect endothelial function. Particular attention has been given to the bioactive chemical profile of these pomaces and their efficacy in various pathological conditions related to endothelial dysfunction. The waste matrices of apple, pear, and sugar beet crops can represent promising starting material for producing "upcycled" products with functional applications, such as the prevention of endothelial dysfunction linked to cardiovascular diseases.

Characterization of phenolics and discovery of α-glucosidase inhibitors in Artemisia argyi leaves based on ultra-performance liquid chromatography-tandem mass spectrometry and relevance analysis

Artemisia argyi leaves (AAL) has been widely used as herbal medicine and food supplement and in China and other Asian countries. The aim of this work is to qualitative and quantitative characterization of phenolic compounds in AAL and screening of natural product inhibitors of α-glucosidase from AAL. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF-MS) was employed to rapid and comprehensive identification of phenolic compounds in AAL, and a total of thirty-three phenolic compounds were identified. High performance liquid chromatography with diode array detection (HPLC-DAD) was established and validated to simultaneously determinate ten main bioactive phenolics compounds in different batches of AAL samples. Meanwhile, the inhibitory capacities of different batches of AAL samples on α-glucosidase were evaluated. Then, relevance analysis, including grey relational analysis and Pearson correlation analysis were employed to investigate the correlations between the contents of phenolic compounds and α-glucosidase inhibitory activities, and discover the α-glucosidase inhibitors in AAL. The relevance analysis results indicated that three phenolic compounds, 3-caffeoylquinic acid, 3,4-dicaffeoylquinic acid and 3,5-dicaffeoylquinic acid could be potential α-glucosidase inhibitors in AAL. Moreover, the α-glucosidase inhibitory activities of the three phenolic compounds were validated by in vitro and in vivo experiments. The possible inhibiting effect of the three phenolic compounds on α-glucosidase was also explored by molecular docking analysis, and the results indicated that the binding of the three α-glucosidase inhibitors to α-glucosidase mainly by hydrogen bonds, hydrophobic forces and ionic bonds. The present research provided a deep insight into phenolic compounds and α-glucosidase inhibitory activities of AAL, and discovered the α-glucosidase inhibitors in AAL.

Kluai Hin (Musa sapientum Linn.) peel as a source of functional polyphenols identified by HPLC-ESI-QTOF-MS and its potential antidiabetic function

To date, information on the polyphenolic composition of Kluai Hin banana peel and pulp and the potential antidiabetic activity of its major active compounds is limited. This study aimed to identify polyphenols in extracts of fresh and freeze-dried Kluai Hin banana peel and pulp (methanol:water; M:W, 80:20 for flavonoids and acetone:water:acetic acid; A:W:A, 50:49:1 for phenolic acids) by RP-HPLC-DAD and HPLC-ESI-QTOF-MS. Additionally, inhibition of α-amylase and α-glucosidase activities was investigated with crude extracts from Kluai Hin banana peel and pulp, and compared with its major polyphenols ((+)-catechin, (-)-epicatechin and gallic acid) and the antidiabetic drug acarbose. (-)-Gallocatechin was the most abundant polyphenol and was detected in all fresh and freeze-dried pulp and peel extracts by RP-HPLC-DAD. Furthermore, unidentified polyphenol peaks of Kluai Hin were further explored by HPLC-ESI-QTOF-MS. The A:W:A fresh peel extract contained more total phenolic content (811.56 mg GAE/100 g) than the freeze-dried peel (565.03 mg GAE/100 g). A:W:A extraction of the fresh and freeze-dried peel of exhibited IC₅₀ values for α-amylase activity 2.66 ± 0.07 mg/ml and 2.97 ± 0.00 mg/ml, respectively, but its inhibitory activity was lower than acarbose (IC₅₀ = 0.25 ± 0.01 mg/ml). Peel extracts inhibited α-glucosidase activity, whereas pulp extracts had no effect. In addition, all standards, except gallocatechin, activated α-amylase activity, while, gallocatechin inhibited α-glucosidase activity better than acarbose. Therefore, we propose a further investigation into the use of Kluai Hin banana peel as a potential functional food for the management of postprandial glycaemic response to reduce diabetes risk and in the management of diabetes with a commercial drug.

Hydroethanolic Extract of Prunus domestica L.: Metabolite Profiling and In Vitro Modulation of Molecular Mechanisms Associated to Cardiometabolic Diseases

High consumption of fruit and vegetables has an inverse association with cardiometabolic risk factors. This study aimed to chemically characterize the hydroethanolic extract of P. domestica subsp. syriaca fruit pulp and evaluate its inhibitory activity against metabolic enzymes and production of proinflammatory mediators. Ultra-high-performance liquid chromatography high-resolution mass spectrometry(UHPLC-HRMS) analysis showed the presence of hydroxycinnamic acids, flavanols, and glycoside flavonols, while nuclear magnetic resonance(NMR) analysis showed, among saccharides, an abundant presence of glucose. P. domestica fruit extract inhibited α-amylase, α-glucosidase, pancreatic lipase, and HMG CoA reductase enzyme activities, with IC50 values of 7.01 mg/mL, 6.4 mg/mL, 6.0 mg/mL, and 2.5 mg/mL, respectively. P. domestica fruit extract inhibited lipopolysaccharide-induced production of nitrite, interleukin-1 β and PGE₂ in activated J774 macrophages. The findings of the present study indicate that P. domestica fruit extracts positively modulate in vitro a series of molecular mechanisms involved in the pathophysiology of cardiometabolic diseases. Further research is necessary to better characterize these properties and their potential application for human health.

A review of pears (Pyrus spp.), ancient functional food for modern times

BACKGROUND

Pears have been world-widely used as a sweet and nutritious food and a folk medicine for more than two millennia.

METHODS

We conducted a review from ancient literatures to current reports to extract evidence-based functions of pears.

RESULTS

We found that pears have many active compounds, e.g., flavonoids, triterpenoids, and phenolic acids including arbutin, chlorogenic acid, malaxinic acid, etc. Most of researchers agree that the beneficial compounds are concentrated in the peels. From various in vitro, in vivo, and human studies, the medicinal functions of pears can be summarized as anti-diabetic,-obese, -hyperlipidemic, -inflammatory, -mutagenic, and -carcinogenic effects, detoxification of xenobiotics, respiratory and cardio-protective effects, and skin whitening effects. Therefore, pears seem to be even effective for prevention from Covid-19 or PM2.5 among high susceptible people with multiple underlying diseases.

CONCLUSION

For the current or post Covid-19 era, pears have potential for functional food or medicine for both of communicable and non-communicable disease.

Contributions from Mexican Flora for the Treatment of Diabetes Mellitus: Molecules of Psacalium decompositum (A. Gray) H. Rob & Brettell

Diabetes mellitus (DM) is cited as a serious worldwide health problem that occupies second place in causes of annual mortality in Mexico. Among Mexican flora, nearly 300 plant species have been employed as hypoglycemic in popular use. Thus, their study entertains great relevance In this context, this work contributes a clear and timely review of the plant species utilized in Traditional Mexican Medicine and experimental biological models in which not only have the hypoglycemic properties of the extracts and the isolated compounds been considered, but also the anti-inflammatory and antioxidant properties, taking into account an integral focus based on the complex mechanisms involved in the pathogenesis and physiopathology of DM. Among the species reviewed, we highlight Psacalium decompositum (Asteraceae), due to the potent hypoglycemic, anti-inflammatory, and antioxidant activity of the sesquiterpenes identified as majority compounds isolated from the root, such as cacalol and cacalone that also possess the capacity of increasing insulin levels. In this manner, the present manuscript attempts to contribute necessary information for the future study of bioactive molecules that are useful in the treatment of DM, as well as also being a contribution to the knowledge and diffusion of Mexican Traditional Medicine.

Valorization of Bio-Residues from the Processing of Main Portuguese Fruit Crops: From Discarded Waste to Health Promoting Compounds

Food processing generates a large amount of bio-residues, which have become the focus of different studies aimed at valorizing this low-cost source of bioactive compounds. High fruit consumption is associated with beneficial health effects and, therefore, bio-waste and its constituents arouse therapeutic interest. The present work focuses on the main Portuguese fruit crops and revises (i) the chemical constituents of apple, orange, and pear pomace as potential sources of functional/bioactive compounds; (ii) the bioactive evidence and potential therapeutic use of bio-waste generated in the processing of the main Portuguese fruit crops; and (iii) potential applications in the food, nutraceutical, pharmaceutical, and cosmetics industries. The current evidence of the effect of these bio-residues as antioxidant, anti-inflammatory, and antimicrobial agents is also summarized. Conclusions of the revised data are that these bio-wastes hold great potential to be employed in specific nutritional and pharmaceutical applications.

Nutritional Properties and In Vitro Antidiabetic Activities of Blue and Yellow Corn Extracts: A Comparative Study

The objective of this research was to designate and identify the profile of fatty acids, sterols, and polyphenol compounds and to demonstrate the antidiabetic activity, in blue corn extracts (BCE) in comparison with the yellow variant of this raw material. All of the maize lines, including the blue corn, were grown in Europe (southwestern part of Poland) and not in the place of origin (South America). In the extracts of the blue corn variety, eight anthocyanin compounds were isolated. The compound found in the largest amount was pelargonidin, followed by cyanidin-3-glucoside and other glycoside derivatives. Unsaturated fatty acids were the main ones found in the lipid fraction of blue and yellow corn, including linoleic acid and oleic acid. Saturated fatty acids, such as stearic and palmitic acid, were present in smaller amounts. The blue corn’s sterol profile was similar to other varieties of this corn, with β-sitosterol and campesterol occurring in the largest amount, alongside smaller amounts of stigmastanol and stigmasterol. The blue corn variety was characterized by a high content of polyphenolic compounds, which show several biological activities, including antidiabetic activity. The strongest in vitro antidiabetic effect was found in the blue corn lines. Among the polyphenolic compounds in both the blue and yellow corn varieties, in the largest amounts, were caffeic acid, procyanidin B2, and gallic acid. Despite the known and proven biological activity of polyphenolic compounds, the fat fraction showed the highest in vitro antidiabetic activity in the BCE studied.

Bioactive Compounds and Health-Promoting Properties of Pear (Pyrus communis L.) Fruits

Consuming food that is rich in antioxidants reduces the risk of developing chronic diseases and oxidative stress. Fruits and vegetables are an excellent source of substances with antioxidant and pro-health properties. Such raw materials, characterized by a high content of polyphenolic compounds and antioxidant capacity, include pear fruits. In this study, the concentrations of bioactive compounds, as well as the antioxidant, anti-inflammatory, and antiproliferative activity in fruits of five selected pear cultivars were determined and compared. LC-MS and UPLC-PDA methods were used to determine the polyphenolic, carotenoid, chlorophyll, and triterpenoid profiles and content, and the antioxidant activity was analyzed using DPPH and ferric-reducing ability of plasma (FRAP) tests. The anti-inflammatory activity was determined against COX-1 and COX-2 enzymes. The cytotoxic activity of the test compounds was assessed against six tumor cell lines. The results showed that the major group of phenolic compounds in all cultivars was phenolic acids. In the group of chromoplastic pigments, chlorophyllide a and 9-cis-β-carotene were the major compounds, while in the triterpene group, ursolic acid was dominant. The antioxidant potential correlated with the content of polyphenols and carotenoids, and was the strongest for the 'Radana' cultivar. The highest antiproliferative activity in all varieties was established for bladder cancer.

Targeted and non-targeted unexpected food contaminants analysis by LC/HRMS: Feasibility study on rice

A widely applicable analytical LC/HRMS method based on ion source optimization, data treatment optimization on rice matrix was developed. The effects of key parameters of ion source, and their interactions on ESI response were studied on HPLC-QTOF. Compared with center points, 40% and 20% increase of response factors in the positive and negative mode can be achieved by ion source optimization, respectively. Data processing strategies inspired from metabolomics and multi-targeted analysis were compared and developed using case and control rice samples. Highly automated workflow using XCMS achieved highest mass accuracy, highest detection rate of 96% for 5 μg/kg in a non-targeted way. A clear distinction between the control and contaminated samples by PCA and PLS-DA was also achieved by this workflow using XCMS, even for the concentration of 5 μg/kg.

A Comprehensive Review of Phytochemistry and Biological Activities of Quercus Species

The Quercus genus provides a large amount of biomaterial with many applications in fields like pharmaceutics, cosmetics, and foodstuff areas. Due to the worldwide dissemination of the genus, many species were used for centuries in traditional healing methods or in the wine maturing process. This review aims to bring together the results about phytoconstituents from oak extracts and their biological applicability as antioxidants, antimicrobial, anticancer, etc. The literature data used in this paper were collected via PubMed, Scopus, and Science Direct (2010–June 2020). The inclusion criteria were papers published in English, with information about phytoconstituents from Quercus species (leaves, bark and seeds/acorns) and biological activities such as antioxidant, antibacterial, antiobesity, anti-acne vulgaris, antifungal, anticancer, antiviral, antileishmanial, antidiabetic, anti-inflammatory. The exclusion criteria were the research of other parts of the Quercus species (e.g., galls, wood, and twigs); lack of information about phytochemistry and biological activities; non-existent Quercus species reported by the authors. The most studied Quercus species, in terms of identified biomolecules and biological activity, are Q. brantii, Q. infectoria and Q. robur. The Quercus species have been reported to contain several phytoconstituents. The main bioactive phytochemicals are phenolic compounds, volatile organic compounds, sterols, aliphatic alcohols and fatty acids. The, Quercus species are intensely studied due to their antioxidant, anti-inflammatory, antimicrobial, and anticancer activities, provided by their phytochemical composition. The general conclusion is that oak extracts can be exploited for their biological activity and can be used in research fields, such as pharmaceutical, nutraceutical and medical.

The Quality of Freeze-Dried and Rehydrated Blueberries Depending on their Size and Preparation for Freeze-Drying

A significant increase in highbush blueberry plantings has been observed annually. However, there is a problem with the handling of fruit that does not meet the requirements for dessert berries. One of the methods to use the fruit is drying. The research was conducted in the Department of Horticulture at the West Pomeranian University of Technology in Szczecin. The fruit was harvested at a plantation specialising in the production of highbush blueberry from irrigated and non-irrigated plots. This study aimed to assess how cutting or pricking highbush blueberry fruit affects the duration of the sublimation drying process – freeze-drying. The biological value of fresh, freeze-dried, and rehydrated fruit was assessed. The amount of fruit left on bushes depended on the weather prevailing in the growing season, especially during the harvest period. The mass of fruit left on the bushes was approx. 1 to 2 t/ha. Although these fruits were small, they had a very high biological value. After freeze-drying and rehydration, the blueberry fruit retained their colour, high content of polyphenols and showed high antidiabetic activity and antioxidant capacity. The large fruit reached the moisture content of approx. 12%, which ensures safe storage and the appropriate texture, after 46 hours of drying, and the smaller fruit - after 32 hours. Fruit cutting or pricking reduced the drying time by half. Reducing this time decreased drying costs and increased biological value.

Phenolic profiling and evaluation of in vitro antioxidant, α-glucosidase and α-amylase inhibitory activities of Lepisanthes fruticosa (Roxb) Leenh fruit extracts

The present study focused on the phytochemical profiling along with evaluation of in vitro antioxidant, α-glucosidase and α-amylase inhibitory activities of various crudes and fractions obtained from Lepisanthes fruticosa (Roxb) Leenh fruit. Ethanolic seed crude extract exhibited the strongest radical scavenging, β-carotene bleaching activity, α-glucosidase inhibition and the highest total phenolic content (TPC). Column chromatography afforded various fractions with fraction M4 being the most potent due to the strongest radical scavenging, β-carotene bleaching, α-glucosidase inhibition and greatest amount of TPC. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of ethanolic seed crude extract and fraction M4 showed the presence of various phytochemicals with antioxidant and antidiabetic properties, which include mostly flavonoids and tannins. The results may suggest that the ethanolic crude seed extract and its fraction could be an excellent source of bioactive phytochemicals with antioxidant and antidiabetic potential.

Compositional characterization of Pyrus ussuriensis Maxim and their antioxidant activities and induction of apoptosis in Bel-7402 cell

In this work, a comparison study on active sites (the total phenolic, total flavonoids, and total triterpenes contents) and antioxidant activities (DPPH, ABTS, and FRAP assays) of different fractions from Pyrus ussuriensis Maxim was evaluated. Moreover, the inhibition capability on human hepatocarcinoma cells Bel-7402 cells and the mechanism was also discussed. Results showed that the ethyl acetate fraction significantly scavenged DPPH and ABTS⁺ radicals, exhibited ferric ion reducing antioxidant, and inhibited Bel-7402 cells proliferation. In addition, oleanolic acid was the dominant compound act on the Bel-7402 cells in the extract and it induced apoptosis by the caspase pathway and induced cell cycle arrest at the G0/G1 phase by inhibiting the cyclin D1/CDK4 pathway. The extracts of P. ussuriensis Maxim were confirmed to have anti-oxidative and antiproliferative effects against Bel-7402 cell in vitro. PRACTICAL APPLICATIONS: Fruits and vegetables which contain high levels of antioxidants can help to reduce the risk of chronic diseases such as cancer. Pyrus ussuriensis Maxim is a kind of edible and medical fruit with multiple bioactivities, whereas the capability to anti-lung cancer activity has not been investigated. The extracts of P. ussuriensis Maxim were revealed to have anti-oxidative and antiproliferative effects against Bel-7402 cell in vitro. Accordingly, it is the first time to verify that oleanolic acid was the main chemical components of P. ussuriensis with antitumor potential.

α-Glucosidase Inhibitory Activity of Phenolic Rich Extracts Obtained from the Seeds of Melastoma saigonense (Kuntze) Merr

The aim of this study was to perform a phytochemical analysis of Melastoma saigonense seed extracts and to determine their α-glucosidase inhibitory activity. The extracts from seeds of M. saigonense indicated that the total phenolic content was in the range between 233.46 and 967.22 mg GAE/g DE, whereas the flavonoids content was in the range between 359.96 and 850.84 mg QE/g DE. The present study of antidiabetic inhibitory activity by in vitro α-glucosidase revealed that the crude extracts using ethyl acetate (EA), butanol (BU) and final aqueous residue extracts (AQ) exhibited a strong α-glucosidase inhibitory effect (IC50 4.42-11.95 μg/mL). The ethyl acetate and butanol extracts of seeds of Melastoma saigonense (Kuntze) Merr. were further fractionated by silica gel column chromatography into four fractions (EAF1−EAF4) and five fractions (BUF1−BUF5), respectively and their bioactivities were investigated. The nine fractions exhibited significant α-glucosidase inhibitory activity (p < 0.05) with an IC50 between 3.42-34.77 μg/mL which is less than the IC50 for standard acarbose (IC50 = 507.26 μg/mL). Among all the fractions, BUF1 and EAF1 exhibited high inhibitory activity against α-glucosidase with BUF1 showing the highest inhibitory activity (IC50 = 3.42 μg/mL). The dominant phenolic acids were sinapic, gallic, ferrulic, syringic, gallic and caffeic acids and the prominent flavonoids were myricetin and quercetin. These findings suggest that the seeds of M. saigonense have potential as a source of antidiabetic agent (s).

Effect of abiotic stress factors on polyphenolic content in the skin and flesh of pear by UPLC-PDA-Q/TOF-MS

Growing social interest in foods with high biological quality results in the need to look for possibilities of increasing the biological quality of food products. The aim of this research was an attempt to estimate the increase of polyphenolic compounds (by UPLC-PDA-MS/MS) in the flesh and skin of pear under the influence of stress elicitors such as UVC radiation, L-EMF, H-EMF and US with various exposure times. The applied stress factors differentiated the content of phenolic acids, flavan-3-ols and flavonols both in flesh and in skin. In all cases, pear skin demonstrated a decrease in the sum of polyphenolic compounds; however, when it comes to flavan-3-ols and procyanidins, the concentration of the compounds increased in two cases: after a 30-min exposure to L-EMF (+ 18%) and after a 5-min exposure to H-EMF (+ 20%). Following a 30-min flesh exposure to US, the determined sum of polyphenolic compounds was + 28% higher than in the control sample. It was observed that the level of flavan-3-ols and procyanidins in the flesh increased after a 60-min exposure to UVC radiation and low-frequency and high-frequency electromagnetic fields, and after a 20-min and 30-min exposure to ultrasounds. The presence of flavonols was only observed in pear skin. The research results show that it is possible to produce juice with a higher content of polyphenolic compounds, because juice is obtained mainly from the flesh; however, there is a need for further research to confirm the observed tendencies in the changes of polyphenolic compounds in fractions of pears.

Comparison between polyphenol profile and bioactive response in blackthorn (Prunus spinosa L.) genotypes from north Serbia-from raw data to PCA analysis

The aim of this work was to investigate and compare the phenolic profile of 15 wild growing blackthorn (Prunus spinosa L.) genotypes from the slopes of Fruška Gora mountain in north Serbia. Their effect in inhibiting i) α-amylase and α-glucosidase activities and ii) colorectal cancer cell line (HT29) growth was also studied. Blackthorn fruit extracts exhibited high phenolic content being enrich in anthocyanins. Principal component analysis was used to correlate the bioactive response with phenolic composition. It was found that derivatives quercetin and anthocyanin peonidin are the major contributors of the inhibition of carbohydrates hydrolyzing enzymes as well as with the antiproliferative effect of blackthorn. Among all samples, the genotype from Beška locality showed the higher capacity in inhibiting alpha-amylase, alpha-glucosidase and HT29 cell growth. Because of high anthocyanin content and higher bioactive response, these genotypes could be recommended for the further cultivation and investigation.

Pear Extract and Malaxinic Acid Reverse Obesity, Adipose Tissue Inflammation, and Hepatosteatosis in Mice

SCOPE

Obesity and diabetes are major public health problems and are emerging as pandemics. Considerable evidence suggests that pear fruit consumption is associated with a lower risk of obesity-related complications. Thus, the present study is conducted to investigate the therapeutic potential of pear extract (PE) for reversing obesity and associated metabolic complications in high-fat diet-induced obese mice.

METHODS AND RESULTS

Obesity is induced in male C57BL/6 mice fed a high-fat diet for 11 weeks. After the first 6 weeks on the diet, obese mice are administered vehicle or PE for 5 weeks. PE treatment decreases body weight gain, expands white adipose tissue (WAT), and causes hepatic steatosis in obese mice, as well as inhibits adipogenesis and lipogenesis. Impaired glucose tolerance and insulin resistance are improved by PE. In addition, PE reduces macrophage infiltration and expression of pro-inflammatory genes and deactivates mitogen-activated protein kinases in WAT. Finally, malaxinic acid is identified as an active component responsible for the anti-obesity effects of PE in mice.

CONCLUSION

The results demonstrate that PE supplementation ameliorates diet-induced obesity and associated metabolic complications and suggest the health-beneficial effects of both pear fruits and malaxinic acid in counteracting these diseases.

Relationship of phenolic composition of selected purple maize (Zea mays L.) genotypes with their anti-inflammatory, anti-adipogenic and anti-diabetic potential

This study aimed to investigate the associations between phenolic composition of selected purple maize genotypes and their anti-inflammatory, anti-adipogenic and anti-diabetic properties in vitro. Anthocyanin-rich water extracts (PMWs) from 20 purple maize genotypes were evaluated in RAW 264.7 macrophages and 3T3-L1 adipocytes under different conditions. Cyanidin-3-O-glucoside (C3G), pelargonidin-3-O-glucoside (Pr3G), peonidin-3-O-glucoside (P3G) and corresponding acylated forms were major anthocyanins in PMW, accompanied by ten tentatively identified non-anthocyanin phenolics. Correlation studies showed that C3G, P3G, and derivatives, but not Pr3G and its acylated form contributed to the biological properties of PMW. Besides anthocyanins, quercetin, luteolin, and rutin were the dominant anti-inflammatory and anti-diabetic components, in terms of down-regulating pro-inflammatory mediator production in inflamed macrophages and adipocytes, modulating diabetes-related key enzymes and improving insulin sensitivity in insulin-resistant adipocytes. Quercetin and phenolic acids, especially vanillic acid and protocatechuic acid, were closely associated with anti-adipogenic properties of PMW via inhibition of the preadipocyte-adipocyte transition.

Effects of Radix Linderae extracts on a mouse model of diabetic bladder dysfunction in later decompensated phase

Background

This study aimed to elucidate the effects and mechanisms of Radix Linderae (RL) extracts on a mouse model of diabetic bladder dysfunction (DBD), especially on later decompensated phase.

Methods

Male C57BL/6J mice were intraperitoneally injected with streptozotocin (STZ) after 4 weeks of high-fat diet (HFD) feeding. DBD mouse models (later decompensated phase) were developed by 12-weeks persistent hyperglycemia and then treated with RL extracts for 4 weeks. During administration, the fasting blood glucose (FBG) test was performed once a week. Four weeks later, oral glucose tolerance test (OGTT), voided stain on paper (VSOP), and urodynamic alteration were explored. We also performed haematoxylin and eosin (H&E) and Masson’s trichrome staining to observe the histology of the bladder. Then, the contractile responses to α, β-methylene ATP, capsaicin (CAP), KCl and carbachol were measured. Moreover, qPCR assay was performed to analyse the bladder gene expression levels of M₃ receptors and TRPV1.

Results

The diabetic mice exhibited higher FBG, OGTT and urine production, and no substantial alteration was observed after RL treatment. Urodynamic test showed the maximum bladder capacity (MBC), residual volume (RV) and bladder compliance (BC), as well as the decrement of voided efficiency (VE) and micturition volume (MV), remarkably increased in the DBD mice. Furthermore, RL treatment significant improved urodynamic urination, with lower MBC, RV, and, BC, as well as higher VE and MV, as compared with the model groups. The wall thickness of the bladder and the ratio of smooth muscle/collagen remarkably increased, and RL could effectively attenuate the pathological change. The response of bladder strips to the stimulus was also reduced in the DBD mice, and RL treatment markedly increased the contraction. Furthermore, the gene expression levels of M₃ receptors and TRPV1 were down-regulated in the bladders of the diabetic mice, whereas RL treatment retrieved those gene expression levels.

Conclusions

RL extracts can improve the bladder voiding functions of the DBD model mice in later decompensated phase, and underlying mechanisms was associated with mediating the gene expression of M₃ receptors and TRPV1 in the bladder instead of improving blood sugar levels.

Electronic supplementary material

The online version of this article (10.1186/s12906-019-2448-1) contains supplementary material, which is available to authorized users.

Characterization and Quantification of Polyphenols and Triterpenoids in Thinned Young Fruits of Ten Pear Varieties by UPLC-Q TRAP-MS/MS

Large quantities of thinned young pears, a natural source of bioactive compounds, are abandoned as agricultural by-products in many orchards. Hence, ten thinned young pear varieties were systematically investigated in terms of their chemical composition and antioxidant potential. Through ultra-performance liquid chromatography coupled with electrospray ionization triple quadrupole mass spectrometry (UPLC-Q TRAP-MS/MS), 102 polyphenols and 16 triterpenoids were identified and individually quantified within a short time using multiple reaction monitoring (MRM). Subsequently, the antioxidant capacities of these pears were determined with DPPH assays, and the correlation between total antioxidant activity and each component was analyzed. The results indicated that the bioactive compound content and antioxidant capacity in thinned pears were considerably high. Regarding chemical composition, chlorogenic acid, quinic acid and arbutin were the primary polyphenols and ursolic acid was the predominant triterpenoid, whereas 27 polyphenolic compounds, especially chlorogenic acid and most of the flavan-3-ols, were the main antioxidants in young pears. These findings should provide a scientific basis for the further use of pear fruit by-products.

Investigating inhibitory activity of novel synthetic sericin peptide on α-D-glucosidase: kinetics and interaction mechanism study using a docking simulation

BACKGROUND

We synthesised a novel sericin peptide (SP-GI) with α-d-glucosidase inhibitory activity, which has a sequence of SEDSSEVDIDLGN. The kinetics of its peptide-induced inhibition on α-d-glucosidase activity and its interaction mechanism merging with molecular docking were both investigated.

RESULTS

SP-GI exhibited significant inhibitory activity with an IC₅₀ of 2.9 ± 0.1 µmol L^-1 and this inhibition was reversible and non-competitive with a K_i value of 1.0 ± 0.1 µmol L^-1 . An interaction study with SP-GI revealed it bound to α-d-glucosidase at a single binding site, resulting in alterations in α-d-glucosidase secondary structure. This led to quenching of intrinsic α-d-glucosidase fluorescence by a static quenching mechanism. Molecular docking results showed that the SP-GI binding site on α-d-glucosidase differed from acarbose, with hydrogen bonding and van der Waals forces being the main binding drivers.

CONCLUSION

These findings suggest the potential use for SP-GI or other natural sericin peptides as dietary supplements for the treatment of type 2 diabetes. © 2017 Society of Chemical Industry.

Phenolic compounds and biological effects of edible Rumex scutatus and Pseudosempervivum sempervivum: potential sources of natural agents with health benefits

The present study outlines a chemical characterization and further effects beneficial to health of edible Rumex scutatus and Pseudosempervivum sempervivum, in addition to presenting the antioxidant, enzyme inhibitory effects and antimicrobial properties of different extracts. The phenolic compounds composition of the extracts was assessed by RP-HPLC-DAD, outlining benzoic acid and rutin as major constituents in P. sempervivum and rutin and hesperidin in R. scutatus. Moreover, further biological effects were tested on key enzymes involved in diabetes mellitus, Alzheimer's disease and skin melanogenesis revealing an important tyrosinase inhibitory effect of Pseudosempervivum water extract. Moreover, both species possessed antimicrobial properties towards bacteria and fungi relevant to public health. Accordingly, we find that R. scutatus and P. sempervivum can be considered as novel functional foods because they are rich sources of biologically active compounds that provide health benefits.

Active compounds, antioxidant activity and α-glucosidase inhibitory activity of different varieties of Chaenomeles fruits

Chaenomeles is an important source for food industry in China, and its planting area is expanding year by year. This study was conducted to evaluate different varieties of Chaenomeles by comparing the chemical compositions, antioxidant activity and α-glucosidase inhibitory activity of peels and fleshes from twelve varieties of Chaenomeles. In the results, peels of Chaenomeles contain more phenolics, flavonoids and triterpenes, and show better antioxidant activity and α-glucosidase inhibitory activity than their fleshes. All varieties of Chaenomeles perform different depend on cultivar and climatic conditions. Oleanolic acid, ursolic acid, protocatechuic acid, rutin, catechin, caffeic acid, syringic acid, epicatechin, hyperin, quercetin, kaempferol and chlorogenic acid are main active compounds in Chaenomeles. Zheng'an, Liufu, Zimugua1, Qijiang and Changjun get Top five scores. This is the first study on the peels and fleshes of twelve varieties of Chaenomeles, and it gives insights into variety selection in the planting and production of Chaenomeles.

Functional constituents of wild and cultivated Goji (L. barbarum L.) leaves: phytochemical characterization, biological profile, and computational studies

Goji (Lycium barbarum L.) leaves are emphasized as a functional tea or as dietary supplements. The phenolic compound profile, antioxidant, enzyme inhibitory, antimicrobial, and antimutagenic activities of leaf extracts from two selected cultivars in comparison with wild-growing plants have been evaluated. HPLC-DAD/ESI-ToF-MS analysis revealed the presence of phenolic acids and flavonoids with chlorogenic acid and rutin being the dominant compounds in the cultivated plants, whereas rutin and kaempeferol-3-O-rutinoside for wild growing ones. In particular, cv. Erma contained the highest amount of chlorogenic acid and showed a strong tyrosinase-inhibitory effect. Staphylococcus aureus, Listeria monocytogenes, and Penicillium funiculosum were the most sensitive strains when exposed to extracts from cultivated plants. Antimutagenic activity was evaluated by Ames' test. The tested extracts provided high protection against mutagenicity induced by 2-anthramine (2-AA) to Salmonella typhimurium strains TA 98 and TA 100 (max. inhibition (%) 88% and 74.2%, respectively). Overall, Goji leaves are a rich source of bioactive compounds with functional properties that need further risk/benefit evaluation when used in foods or health-promoting formulations.

Antioxidative, potentially anti-inflammatory, and antidiabetic properties, as well as oxidative stability and acceptability, of cakes supplemented with elicited basil

The aim of the study was to investigate the effect of addition of basil elicited with jasmonic acid (JA) on the biological properties, oxidative stability, and sensory quality of cakes. Simulated gastrointestinal digestion was used for determination of bioavailability. The antioxidant, anti-inflammatory and antidiabetic potential of fortified cakes were significantly higher than those of the control cakes. The antioxidant activity of the tested cakes was increased after addition of basil, proportionally to the amount of the additive. Additionally, in some cases, better results were obtained using JA-elicited basil instead of the control basil. Basil addition inhibited fat peroxidation in the cakes, measured as the malondialdehyde content. Cakes supplemented with the control and elicited basil were characterized by satisfactory consumer acceptability. Based on the data obtained in the present study, it can be concluded that JA-elicited basil (especially elicited with 100µM jasmonic acid) can be recommended for food technologists.

Effect of boiling and drying process on chemical composition and antioxidant activity of Chaenomeles speciosa

Chemical composition and antioxidant activity of fresh and boiled Chaenomeles speciosa (CS) slices dried by different drying methods were determined. Data were analyzed by principle component analysis and cluster analysis. All dried boiled CS from dried fresh CS slices form main cluster. The results also demonstrated that both drying methods, freeze drying and hot air drying at 60 °C had good potential in the industrial drying of fresh and boiled CS. Fresh CS dried by hot air drying at 60 °C was more suitable for the industrial production.