Hypoglycemic Activity Research Articles

Effect of Different Probiotic Fermentations on the Quality of Plant-Based Hempseed Fermented Milk

This study investigated the effects of three different single-strain probiotics Lactiplantibacillus plantarum XD117, Lacticaseibacillus paracasei LC-37, and Lacticaseibacillus rhamnosus LGG, on the quality of hempseed fermented milk. The main findings were that adding probiotics increased the inhibition rate of α-glucosidase and pancreatic lipase in hempseed fermented milk significantly. Non-targeted metabolomic correlation analysis results confirmed that 14 substances, including three flavonoids, six amino acids and their derivatives, and five short peptides, were positively correlated with the hypoglycemic and hypolipidemic activities of hempseed fermented milk. Furthermore, a total of 59 volatile flavor compounds were identified, including aldehydes, alcohols, ketones, acids, and esters, and the role mapping of different probiotic communities was provided. These results can guide the development of hempseed fermented milk with unique flavor, rich probiotic content, and significant functional characteristics.

The Extraction, Biosynthesis, Health-Promoting and Therapeutic Properties of Natural Flavanone Eriodictyol.

Eriodictyol is a flavanone compound commonly found in several edible plants. Ultrasound-assisted extraction and high-performance liquid chromatography (HPLC) are commonly used methods for the separation and analysis of eriodictyol. Many studies show that some micro-organisms can produce eriodictyol as a host. What is more, eriodictyol has a wide range of health benefits, including skincare, neuroprotective, hypoglycemic, anti-inflammatory, and antioxidant activities. In addition, the therapeutic properties of eriodictyol are cardioprotective, hepatoprotective, anticancer, with protective effects on the lungs and kidneys, and so on. This review examines the extraction, biosynthesis, and health and therapeutic properties of the natural compound eriodictyol and its value in medicine and food.

Costus igneus: A Versatile Herbal Remedy for Multiple Health Conditions.

Costus igneus, commonly known as the insulin plant, is a potent medicinal herb with a wide range of pharmacological activities. Traditionally used in diabetes management, recent studies have highlighted its antidiabetic, antioxidant, antimicrobial, hepatoprotective, and kidney stone inhibitor properties. Phytochemical analyses reveal the presence of saponins, flavonoids, alkaloids, steroids, and terpenoids, which contribute to its therapeutic effects. In various in-vitro and in-vivo models, Costus igneus demonstrated significant hypoglycemic activity. The plant exhibits strong antioxidant activity, as evidenced by FRAP, DPPH, and ABTS assays, with notable radical scavenging and reducing power. Other miscellaneous pharmacological activities include anti-inflammatory, anti-arthritic, cytotoxicity and hypotensive effects. These findings support Costus igneus as a safe and cost-effective herbal remedy for managing diabetes and other ailments, highlighting its potential for future therapeutic applications and the development of herbal formulations.

Evaluation of Hypoglycemic Polyphenolic Compounds in Blueberry Extract: Functional Effects and Mechanisms

Blueberries are rich in polyphenols, which exhibit significant anti-diabetic activity. In this study, polyphenolic compounds with potential hypoglycemic activity were identified from blueberry polyphenol extract (BPE). This research focused on assessing the hypoglycemic effects of BPE and its polyphenolic compounds (dihydroquercetin and gallic acid) on diabetic mice induced by streptozotocin (STZ) and high-fat diet (HFD), as well as the related fundamental mechanisms. The findings revealed that BPE treatment effectively reduced levels of fasting blood glucose (FBG) by decreasing hepatic oxidative stress, regulating lipid metabolism disorders and improving insulin resistance. Investigations into the insulin signaling pathway revealed that BPE can modulate the expression of Egfr, Insr, Irs-1, Pi3k and Akt, thereby influencing glucose metabolism. This study provides a research foundation for considering blueberry polyphenols as a nutritional dietary supplement for the prevention and intervention of diabetes.

Evaluation of the Hypoglycemic Activity of Methanolic Extract of Foeniculum Vulgare in Streptozotocin-induced Diabetic Wistar Rats.

This study aimed to assess the hypoglycemic effects of methanolic extract of Foeniculum vulgare in male Wistar rats that were diabetic due to streptozotocin. Experimental diabetes was initially induced in male Wistar rats by intravenous injection of streptozotocin (55 mg/kg). Subsequently, the rats received daily oral administration of the methanolic extract of Foeniculum vulgare (250 mg/kg) and the standard drug metformin (300 mg/kg) for 28 days. Furthermore, a tolerance test was carried out. The study findings suggest that the diabetic rats in the untreated control group showed hyperglycemia and significant weight loss, as well as polydipsia, polyphagia, and polyuria. However, rats treated with methanolic extract of Foeniculum vulgare for 28 days showed a significant reduction in blood glucose levels and a marked improvement in body weight. Additionally, there was a notable decrease in the daily rate of food consumption and water intake and a significant reduction in serum glucose level, triglycerides, total cholesterol, creatinine, urea, AST, and ALT levels compared to the untreated diabetic control group. Histopathological examination revealed that after 28 days of treatment with 250 mg/kg of methanolic extract of the Foeniculum vulgare, the size of the islets of Langerhans in the pancreas tissue was decreased. Moreover, liver tissue demonstrated normalization with a normal central lobular structure, and kidney tissue showed normalization with a normal Bowman's capsule. These findings suggest that the methanolic extract of Foeniculum vulgare can potentially treat diabetes and should be evaluated further for drug development.

A Potential Diabetic-Friendly Food Material: Optimization, Nutritional Quality, Structural Characteristics, and Functional Properties of Oat and Purple Potato Fermented by Ganoderma lucidum Mycelium

Dietary intervention is the basis for the treatment of diabetes mellitus. This study employed Ganoderma lucidum (GL) mycelium to ferment a compound medium of oat and purple potato (OPP), optimized fermentation conditions to increase the triterpene content in the resulting product (F-OPPF), and systematically investigated the impact of fermentation on the nutritional quality, structural characteristics, and functional properties of OPP. The results indicated that the triterpene content in F-OPPF significantly increased from 8.53 mg/g to 17.23 mg/g under optimal conditions (temperature: 28 °C, inoculum size: 10%, material quantity: 36 g/250 mL, and fermentation time: day 13). Fermentation resulted in enhanced nutritional quality, with increased contents of protein, soluble protein, crude fiber, ash, mineral elements, essential amino acids, polysaccharides, flavonoids, and total phenols. Mycelium not only enveloped the OPP surface but also penetrated its interior, forming a porous honeycomb-like structure. The types of reactive groups and crystals (C + V-type) were not changed after fermentation, while the crystallinity increased. F-OPPF exhibited positive changes in thermogravimetric properties, antioxidant and hypoglycemic activities, and adsorption capacity of insoluble dietary fiber. Additionally, incorporating F-OPPF into the diet markedly reduced fasting blood glucose levels and promoted weight gain in T2DM rats induced by a high-fat diet and streptozotocin. The fermented groups exhibited improvements in glyco- and lipo-metabolism, oxidative stress, and the function and pathological morphology of the pancreas, liver, and kidneys compared to the unfermented group. Collectively, these findings suggested that GL mycelium fermentation enhanced the nutritional and functional values of OPP, and F-OPPF holds potential as a raw material for developing diabetic-friendly foods.

The role of curcumin in modulating circular RNAs and long non-coding RNAs in cancer.

Cancer is one of the primary causes of human disease and death, with high morbidity and mortality rates. Chemotherapy, one of the most common therapeutic techniques, functions through a variety of mechanisms, including the production of apoptosis and the prevention of tumor development. Herbal medicine has been the subject of numerous investigations due to its potential as a valuable source of innovative anti-cancer products that target multiple protein targets and cancer cell genomes. Curcumin, a polyphenol that is the major bioactive ingredient of turmeric, exhibits pharmacological and biological efficacy with antioxidant, anti-inflammatory, anticancer, cardioprotective, neuroprotective, and hypoglycemic activity in humans and animals. Recent research suggests that curcumin changes noncoding RNA (ncRNA), such as long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs), in various types of cancers. Both circRNAs and lncRNAs are ncRNAs that can epigenetically modulate the expression of multiple genes via post-transcriptional regulation. In this study, we outline curcumin's activities in modulating signaling pathways and ncRNAs in various malignancies. We also described curcumin's regulatory function, which involves blocking carcinogenic lncRNAs and circRNAs while increasing tumor-suppressive ones. Furthermore, we intend to demonstrate how ncRNAs and signaling pathways interact with each other across regulatory boundaries to gain a better understanding of how curcumin fights cancer and create a framework for its potential future therapeutic uses.

ERRATUM: Polysaccharides from the Fruits of Balanites aegyptiaca Del.: Preliminary Characterization, Antioxidant, Hypoglycaemic, and Anti-inflammatory Activities

ERRATUM: Polysaccharides from the Fruits of Balanites aegyptiaca Del.: Preliminary Characterization, Antioxidant, Hypoglycaemic, and Anti-inflammatory Activities

Encapsulation of Antarctic krill peptide by polysaccharide-based nanoparticles: Preparation, characterization, evaluation of stability and hypoglycemic activity

The aim of this study was to construct a chitosan quaternary ammonium salt (HTCC)/sodium alginate (SA) nanoparticle delivery system for the encapsulation of Antarctic krill peptide (AKP), with the goal of enhancing its stability and post-digestive hypoglycemic activity. Additionally, the effect of the content and encapsulation sequence of HTCC/SA on the structure and properties of AKP-loaded nanoparticles (AKP-loaded NPs) was investigated. As the content of the outermost wall material (HTCC) increased, the particle size of nanoparticles initially increased and then decreased. Concurrently, the zeta potential showed a trend of increase, ranging from -38.77 to 46.07 mV. When SA was used as the outermost wall material, the nanoparticles exhibited a smaller particle size (240.1 nm) and better dispersibility. Electrostatic interaction and hydrogen bonding were the major forces involved in the formation of AKP-loaded NPs. X-ray diffraction revealed that AKP was successfully encapsulated in an amorphous state. Scanning electron microscopy showed that AKP-loaded NPs had an elliptical or blocky appearance. Moreover, AKP-loaded NPs demonstrated good storage and temperature stability, while nanoparticles with HTCC in the outermost layer (HTCC:SA=2:1) showed good pH and ionic stability. During simulated digestion, AKP-loaded NPs inhibited the release of AKP in gastric fluid. Consequently, the hypoglycemic activity of digested AKP-loaded NPs was remarkably higher than unencapsulated AKP. Notably, the nanoparticles with HTCC in the outermost layer provided superior hypoglycemic activity. In summary, the polysaccharide-based delivery system exhibited great potential to improve the stability and post-digestive hypoglycemic activity of AKP, broadening its applications in the food and pharmaceutical industries.

Purification, structural identification, in vitro hypoglycemic activity and digestion characteristics of polysaccharides from the flesh and peel of wampee (Clausena lansium)

In this study, two polysaccharides were isolated from the flesh and peel of wampee, termed as PWP-F and PWP-P respectively, and their structural characteristics, in vitro antioxidant and hypoglycemic activities and digestion were investigated. Results indicated the molecular weight of PWP-F was higher than that of PWP-P and they were both mainly composed of galactose and arabinose. Both polysaccharides exhibited α-type and β-type glycosidic linkages based on FTIR analysis. NMR spectroscopy revealed that PWP-F mainly consisted of α-Araf-(1→, →3,5)-α-Araf-(1→, →2,5)-α-Araf-(1→, →4) → β-Galp-(1 → and α-GalpA-(1→, while PWP-P was composed of α-Araf-(1→, →3)-α-Araf-(1→, →5)-α-Araf-(1→, →3,6) → β-Galp-(1→ and α-GalpA-(1→. Scanning electron microscopy showed that PWP-P had more porous surface structure compared to PWP-F. Moreover, PWP-P exhibited superior antioxidant activity and significant inhibition of both α-glucosidase and α-amylase compared to PWP-F. Specifically, PWP-P demonstrated mixed inhibition against α-glucosidase and α-amylase. In vitro digestion results showed the molecular weight, polysaccharide and reducing sugar content of PWP-F and PWP-P decreased after simulative gastrointestinal digestion. Overall, PWP-P has great potential as a kind of new antioxidant and hypoglycemic agent.

Hypoglycemic activity of enzymatically extracted Eucommia ulmoides polysaccharide (EUL-w1) on IR-HepG2 cell via the AMPK/PI3K/Akt signaling pathway

This study devised optimal conditions to extract Eucommia ulmoides leaf (EUL) polysaccharides using a cellulase and pectinase composite enzyme system based on one-way experiments and response surface methodology. Crude EUL polysaccharides (EULPs) were extracted and purified using a DEAE chromatography column. The polysaccharides EUL-w, EUL1, EUL2, and EUL3 were obtained by elution with water, 0.1 mol/L NaCl, 0.2 mol/L NaCl, and 0.3 mol/L NaCl, respectively. The EUL-w fraction had the highest hypoglycemic activity based on its α-amylase and α-glucosidase activities. The preliminary structure of purified EUL-w1 was elucidated. In vitro hypoglycemic activity studies and metabolomics analyses suggested that EUL-w1 modulated glucose metabolism by mediating the AMPK/PI3K/Akt signaling pathway. Our findings provide novel insights and data support for the utilization of EULPs as an emerging food resource in functional foods.

Impact of lactic acid bacterial fermentation on the chemical composition, antioxidant capacities and flavor properties of dandelion

Dandelion is a medicinal and food plant with a long history of medicinal use, but its application as a functional food has been limited. In this study, the fermentation characteristics of four lactic acid bacteria (LAB) in dandelion were investigated and aimed to screen out the LAB that can improve the nutrition and flavor of dandelion. The results showed that all strains grew well, with L. plantarum having the lowest pH and highest total acidity after fermentation. Fermented dandelions (FDs) showed significantly higher total phenolic and flavonoid contents. The antioxidant and hypoglycaemic activities were also enhanced. Lactic and tartaric acids contents increased significantly after fermentation. The three characteristic phenolic acids were differently changed by different LAB strains. L. plantarum-FD had the highest content of chlorogenic acid (17.22 mg/g), and L. casei-FD had the highest content of caffeic and chicoric acids (0.77 mg/g and 14.90 mg/g, respectively). LAB improved the herbal flavor of dandelion by reducing alcohols, increasing acids and altering the concentrations of other volatiles. Aldehydes and esters increased more in the L. plantarum- and L. fermentum-FDs than in the other groups. L. fermentum added pyrazines in particular but also produced unpleasant butanoic acid and methylpyrazine. Overall, L. plantarum fermentation has shown great potential in improving the flavor and enhancing the biological functions of dandelion. It will be beneficial for enriching dandelion products and increasing added value.

Structure elucidation and molecular mechanism of an immunomodulatory polysaccharide from Nostoc commune

Nostoc commune Vaucher, a terrestrial and benthic blue-green alga, widely used in food and medicine worldwide. N. commune Polysaccharides (NCVP) have excellent biological activities, especially immunomodulatory, hypoglycemic and anti-tumor activities. However, the mechanism and structure-activity relationship of NCVP has been less studied. In this study, based on methylation and NMR results, a novel polysaccharide NCVP2 with 135 kDa, containing→4)-α-D-Galp-(1→, → 4)-β-D-Glcp-(1→, and →4)-α-D-Xylp-(1→ residues as the backbon, was sequentially purified from N.commune by DEAE-52 and Sephadex G-100 column. NCVP2 (50 μg/mL) exhibited the strong in vitro immunomodulatory activity by promoting the generation of nitric oxide (NO) and reactive oxygen species (ROS). A total of 2048 differentially expressed genes (DEGs) were identified by RNA-seq, including 1019 down-regulated genes and 1065 up-regulated genes. These DEGs were mainly enriched in the immune-related biological processes, involving in Mitogen-activated protein kinase (MAPK) and Toll-like receptor (TLR) signaling pathways by GO and KEGG enrichment analysis. Furthermore, Western blot results proved NCVP2 could recognize TLR2 and TLR4/MD2, and regulate TLR7/IRF7, MAPK and PI3K/AKT signaling pathways. In summary, a novel polysaccharide NCVP2 from N.commune was proposed to exhibit significant immunomodulatory effects with multiple-paths and targets, and has great potential in the development of healthy foods such as immunomodulators.

Hypoglycemic and antihyperglycemic effects of Abelmoschus esculentus and Alchornea cordifolia in normal and alloxan-induced diabetic rats

BackgroundAbelmoschus esculentus and Alchornea cordifolia are commonly used in Traditional Chinese Medicine (TCM) to treat several diseases. Abelmoschus esculentus is used to treat infertility and menorrhagia, while Alchornea cordifolia is used for the treatment of venereal diseases, cough, and diarrhoea. However, very few studies assessed the antidiabetic effects of these plants. Therefore, this study aimed to investigate the hypoglycemic and antihyperglycemic effects of aqueous extract of A. esculentus fruits and A. cordifolia leaves. Material and MethodsFresh Abelmoschus esculentus fruits and the powder from the dried leaves of Alchornea cordifolia leaves were prepared by maceration in the aqueous phase (200g/100mL and 50g/100mL respectively) for 24 hours, then filtered and concentrated in an oven at 45°C. Diabete was induced to male Wistar rats by a single intraperitoneal injection of alloxan (150 mg/kg, b.w). Rats with a blood glucose level greater than or equal to 200 mg/dL were selected, divided into groups and were daily administered orally with either aqueous extracts of A. esculentus at 30 mg/kg (AEAE30) or A. cordifolia at 400 mg/kg (AEAC400) for 14 consecutive days. For comparison, acarbose (100 mg/kg), glibenclamide (5 mg/kg), and metformin (500 mg/kg) were administered orally as reference drugs. Moreover, insuline was also used as a positive control and administered intraperitoneally at a dose of 5 IU/kg. Then, blood glucose levels, oral glucose tolerance test, oral maltose tolerance club, body weight and hemoglobin were assessed. For evaluation of the aqueous extracts in the intestinal transit, imodium (2 mg/kg, p.o) and fructine (5 mg/kg, p.o) were used as a positive control to determine the spasmolytic and laxative activities, respectively. The histopathological study of the liver, kidney, pancreas, testis, epididymis, and seminal vesicle was also carried out using the hematoxyline & eosin (H&E) technique. ResultsAEAE30 and AEAC400 significantly reduced (P<0.001) fasting blood glucose (FBG) levels and significantly prevented (P<0.001) postprandial glycemia in AI-db rats following oral glucose tolerance test (OGTT) and oral maltose tolerance test (OMTT) in alloxan-induced diabetic rats (AI-db). In normoglycemic and insulin-resistant (IR) rats, AEAE30 significantly prevented the post-prandial blood glucose level during the OGTT (P<0.01) only in normoglycemic rats. At the end of treatment, AEAE30 significantly reduced the relative weight of the liver (P<0.01) and significantly increased (P<0.001) the relative weight of the testes and pancreas while AEAC400 significantly increased the relative weight of the testes compared to untreated AI-db rats. The histopathological study revealed a restoration of alloxan-induced tissue damage close to the normal control group in AI-db animals treated with plant extracts, as well as an increase in sperm density in the epididymis unlike in the untreated AI-db group. ConclusionThese findings suggested that AEAE and AEAC exhibited hypoglycemic and antihyperglycemic activities and could be therefore a useful source of antidiabetic agent.

Identification of TIGAR, a direct proteomic target associated with the hypoglycemic effect of Berberine

Diabetes mellitus is a global chronic metabolic disease and the prevalence of diabetes mellitus is increasing dramatically every year. Berberine (BBR) from Coptidis Rhizoma has potent hypoglycemic effects, however, the specific proteins targeted by berberine that contribute to its hypoglycemic action remain to be elucidated. In this work, TIGAR (TP53-induced glycolysis and apoptosis regulator) was identified as a direct target protein for berberine using activity-based protein profiling (ABPP) and other chemical proteomics techniques with active photoaffinity probes as chemical tools. In addition, the study revealed that berberine-targeted TIGAR attenuated the conversion of fructose-2, 6-bisphosphate to fructose-6-phosphate. This study demonstrated an innovative mechanism by which berberine directly targets TIGAR and its hypoglycemic effects. Therefore, TIGAR emerges as a novel target for the treatment of diabetes mellitus, with TIGAR inhibitors offering a new and promising therapeutic strategy for managing the disease.

Purification, characterization, and hypoglycemic activity of exopolysaccharides from Lactiplantibacillus plantarum MY04

As natural polymers, Lactiplantibacillus plantarum exopolysaccharides (EPS) possess a wide range of bioactivities but suffer from low yields and unclear relationships between functional activity and structure. To this end, the chemical structure and bioactive properties of EPS from Lactiplantibacillus plantarum MY04 were investigated. As a result, three polysaccharide fractions (EPS-1, EPS-2, EPS-3) were separated and purified, of which EPS-2 had better antioxidant activity and α-glucosidase inhibitory ability. More importantly, EPS-2 can significantly enhance insulin sensitivity in HepG2 cells by upregulating enzyme activities in the glycolytic pathway and mitigating oxidative stress-induced damage. In addition, the structural characterization of EPS-2 was also comprehensively elucidated. It was found that EPS-2 was mainly composed of mannose with a molecular weight of 2.3 × 106 Da, and its main chain structure is →3)-Manp-(1 → 2)-Manp-(1 → 2,6)-Manp-(1 → 2,6)-Manp-(1→, providing a theoretical basis for understanding the relationship between structure and function of polysaccharides.

Construction and characterization of Laminaria polysaccharide functionalized selenium nanoparticles based on an activity-oriented approach

Laminaria polysaccharides (LP) have been shown to effectively stabilize selenium nanoparticles (SeNPs), forming LP–SeNP complexes with enhanced bioactivity. However, the correlation between their bioactivity and physicochemical properties remains inadequately explored. This study used chemical reduction with LP as stabilizer to investigate how LP-to-selenium mass ratio (LPSMR), reaction time, and temperature influence particle size, selenium content, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of LP–SeNPs. The results showed that enhanced DPPH scavenging correlated with higher selenium content and smaller particle size, primarily modulated by LPSMR and temperature. Under optimal conditions (LPSMR of 1; temperature of 25°C), the resulting LP–SeNPs exhibited uniform morphology with a particle size of 81.41nm and selenium content of 653.91mg/g. This stability was achieved through non-covalent interactions between LP and SeNPs, providing superior light and acid resistance compared to unmodified SeNPs. Notably, LP–SeNPs showed synergistic antioxidant effects, with lower half-maximal inhibitory concentration (IC50) values for scavenging DPPH, hydroxyl, and superoxide anion radicals than LP or SeNPs alone, and enhanced hypoglycemic activity. Cytotoxicity assays confirmed LP–SeNPs had reduced toxicity compared to Na2SeO3 and selenopeptide. These findings provide insights into the structure-activity relationships of LP–SeNPs and support their potential application as antioxidant and hypoglycemic agents.

EFFECTS OF AQUEOUS EXTRACT OF Andira inermis STEM BARK ON SOME REPRODUCTIVE PARAMETERS OF MALE WISTAR RATS

Andira inermis stem bark has been used by herbal practitioners in the treatment of many ailments. Its Pharmacological activities include Anti-oxidant activity, haematological activities, hypoglycaemic activity and antiplasmodia activities. This study seeks to evaluate the effect of aqueous stem bark extract of Andira inermis on some gonadal hormones, sperm count and sperm motility. Thirty-two male Wistar rats weighing 100-120g were randomized into Four (4) groups consisting eight (8) rats each. The animals were allowed to undergo acclimatization for 14days. Animals in group 1 served as the control, group 2, 3 and 4 were the treatment groups. Group 1 received free animal feed and water. Group 2, 3 and 4 received 100, 250 and 500mg/kg aqueous extract of Andira inermis stem bark administered orally daily for 90days. Twenty-four hours after the last administration, rats were sacrificed and cardiac puncture was used to collect the blood for centrifugation. The extract produced a significant (P&lt;0.05) increase in serum testosterone, follicle stimulating hormone, and luteinizing hormone respectively at 100mg/kg body weight but had no significant effect on luteinizing hormone and testosterone hormone at 250mg/kg and 500mg/kg bodyweight compared to normal control. At 250mg/kg and 500mg/kg treatment, follicle stimulating hormone was significantly decreased compared to control. Sperm counts decreased significantly from 22.13±0.53million/ml to 13.00±1.16 million/ml and sperm motility from 11.25±0.41 million/ml to 8.00 ± 0.59 million/ml after treatment. Data was expressed as the mean ± SEM. Statistical comparisons between various treatment groups was determined using one-way analysis of variance (ANOVA).

Synthesis and biological evaluation of esculetin derivatives as antidiabetic agents

Esculetin derivatives 4a-4j (including six novel hydroxylated/halogenated derivatives 4a, 4d, 4e, 4f, 4g, 4h) were synthesized through Perkin reaction with 2,4,5-trihydroxybenzaldehyde and appropriate phenylacetic acid as raw materials, and screened for α-glucosidase and α-amylase inhibitory activities. Among these compounds, compound 3-(3-iodophenyl)-6,7-dihydroxy-2H-chromen-2-one (4d) showed promising hypoglycaemic activity with half maximal inhibitory concentration (IC50) values of 0.18±0.03 mM and 1.82±0.18 mM against α-glucosidase and α-amylase, respectively, classifying it as a mixed-type inhibitor. Compound 4d could statically quench the intrinsic fluorescence of enzymes, which bound to enzymes mainly through hydrogen bonding and hydrophobic interactions affecting the microenvironment of proteins. Compound 4d also exhibited antioxidant activity, which demonstrated good scavenging effects for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) free radicals. Furthermore, compound 4d still maintained a certain degree of hypoglycemic and antioxidant activities after simulated gastrointestinal digestion. The oral toxicity study showed that compound 4d had no significant effect on the serum biochemical indices and organs of mice, indicating its safety profile. This study suggests that esculetin may be a potential skeleton to the development of hypoglycaemic drugs.

Changes in the Profile of Phenolic Compounds and in the Antioxidant, Hypoglycemic, and Antidiabetic Activities of a Beverage Based on Sesame By-Product Caused by the Simulated Gastrointestinal Digestion Process

The by-product of extracting oil from sesame has good functional properties for use in the development of new food products. In this study, the effect of simulated gastrointestinal digestion on the bioaccessibility of phenolic compounds, as well as the antioxidant, antidiabetic, and hypoglycemic properties of a beverage from sesame by-products was analyzed. Oral digestion significantly decreased the total phenolic content of the beverage, while the total flavonoid content increased. Both phytochemicals increased after gastric and intestinal digestion. Twenty-five phenolic compounds were characterized in the sesame by-product beverage, including feruloylquinic acid, which was present in all the digestive fractions analyzed. The most abundant free phenolic was quercetin, which was also present in all the digested fractions. On the other hand, the most abundant phenolic in the digested fractions was isorhamnetin. During gastrointestinal digestion, the antioxidant activity and inhibitory effects on the α-glucosidase and DPP-IV of the beverage significantly improved, while the ability to inhibit the α-amylase significantly increased during oral digestion, remaining constant throughout digestion. Correlation analysis indicated that flavonoids, including quercetin, may be the compounds with the greatest effect on the evaluated activities. The results of this study not only improve the understanding of the impact of gastrointestinal digestion on the bioaccessibility of phenolic compounds but also suggest potential applications in formulating functional foods with enhanced antioxidant, hypoglycemic, and antidiabetic properties, contributing to the development of health-promoting food products.