Alpha Glucosidase Inhibitory Activities of Plants with Focus on Common Vegetables

Redox-Modulating Capacity and Effect of Ethyl Acetate Roots and Aerial Parts Extracts from Geum urbanum L. on the Phenotype Inhibition of the Pseudomonas aeruginosa Las/RhI Quorum Sensing System

Pseudomonas aeruginosa is an opportunistic pathogen that causes nosocomial infections of the urinary tract, upper respiratory tract, gastrointestinal tract, central nervous system, etc. It is possible to develop bacteremia and sepsis in immunocompromised patients. A major problem in treatment is the development of antibiotic resistance. Therefore, new preparations of natural origin are sought, such as plant extracts, which are phytocomplexes and to which it is practically impossible to develop resistance. Geum urbanum L. (Rosacea) is a perennial herb known for many biological properties. This study aimed to investigate the redox-modulating capacity and effect of ethyl acetate (EtOAc) extracts from roots (EtOAcR) and aerial parts (EtOAcAP) of the Bulgarian plant on the phenotype inhibition of the P. aeruginosa Las/RhI quorum sensing (QS) system, which primarily determines drug resistance in pathogenic bacteria, including biofilm formation, motility, and pigment production. We performed QS assays to account for the effects of the two EtOAc extracts. At sub-minimal inhibitory concentrations (sub-MICs) ranging from 1.56 to 6.25 mg/mL, the biofilm formation was inhibited 85% and 84% by EtOAcR and 62% and 39% by EtOAcAP extracts, respectively. At the same sub-MICs, the pyocyanin synthesis was inhibited by 17-27% after treatment with EtOAcAP and 26-30% with EtOAcR extracts. The motility was fully inhibited at 3.12 mg/mL and 6.25 mg/mL (sub-MICs). We investigated the inhibitory potential of lasI, lasR, rhiI, and rhiR gene expression in biofilm and pyocyanin probes with the PCR method. Interestingly, the genes were inhibited by two extracts at 3.12 mg/mL and 6.25 mg/mL. Antiradical studies, assessed by DPPH, CUPRAC, and ABTS radical scavenging methods and superoxide anion inhibition showed that EtOAcAP extract has effective antioxidant capacity. These results could help in the development of new phytocomplexes that could be applied as biocontrol agents to inhibit the phenotype of the P. aeruginosa QS system and other antibiotic-resistant pathogens.

Investigation of alpha-glucosidase inhibition activity of Artabotrys sumatranus leaf extract using metabolomics, machine learning and molecular docking analysis

One way to treat diabetes mellitus type II is by using α-glucosidase inhibitor, that will slow down the postprandial glucose intake. Metabolomics analysis of Artabotrys sumatranus leaf extract was used in this research to predict the active compounds as α-glucosidase inhibitors from this extract. Both multivariate statistical analysis and machine learning approaches were used to improve the confidence of the predictions. After performance comparisons with other machine learning methods, random forest was chosen to make predictive model for the activity of the extract samples. Feature importance analysis (using random feature permutation and Shapley score calculation) was used to identify the predicted active compound as the important features that influenced the activity prediction of the extract samples. The combined analysis of multivariate statistical analysis and machine learning predicted 9 active compounds, where 6 of them were identified as mangiferin, neomangiferin, norisocorydine, apigenin-7-O-galactopyranoside, lirioferine, and 15,16-dihydrotanshinone I. The activities of norisocorydine, apigenin-7-O-galactopyranoside, and lirioferine as α-glucosidase inhibitors have not yet reported before. Molecular docking simulation, both to 3A4A (α-glucosidase enzyme from Saccharomyces cerevisiae, usually used in bioassay test) and 3TOP (a part of α-glucosidase enzyme in human gut) showed strong to very strong binding of the identified predicted active compounds to both receptors, with exception of neomangiferin which only showed strong binding to 3TOP receptor. Isolation based on bioassay guided fractionation further verified the metabolomics prediction by succeeding to isolate mangiferin from the extract, which showed strong α-glucosidase activity when subjected to bioassay test. The correlation analysis also showed a possibility of 3 groups in the predicted active compounds, which might be related to the biosynthesis pathway (need further research for verification). Another result from correlation analysis was that in general the α-glucosidase inhibition activity in the extract had strong correlation to antioxidant activity, which was also reflected in the predicted active compounds. Only one predicted compound had very low positive correlation to antioxidant activity.

Synthesis of aminomethyl linked (+)-usnic acid derivatives via the Mannich reaction and evaluation of their biological activities

(+)-Usnic acid (UA), a natural dibenzofuran derivative, abundantly produced by lichens and possess wide number of biomedical applications including antibacterial, anti-inflammatory, anti-oxidant and anticancer activities. In the present study, as series of usnic acid derivatives (3a-3i) were synthesised using Mannich reaction assessed for their antioxidant, α-glucosidase, and anticancer activities. The in vitro antioxidant activity showed that compound 3d displayed potent antioxidant activity by scavenging the activities of DPPH and ABTS+. The compounds 3d and 3e showed potent cytotoxic activity against HepG2 cancer cells by arresting the cell cycle at S phase and regulating the Bax/BcL2 expression and subsequently induce the apoptosis. Overall, the results clearly indicated that (+)-usnic acid derivatives bearing secondary amines are useful scaffolds for the development of drug candidates for treatment of oxidative stress mediated cancer and metabolic disorders.

Bioactivity Evaluation and Phytochemical Characterization of Euonymus alatus (Thunb.) Siebold Leaf Extract

BACKGROUND

Euonymus alatus (E. alatus) has traditionally been used for medicinal purposes, and its leaves are considered edible. While E. alatus is known for its diverse biological activities, the antioxidant, antidiabetic, and anticancer effects of its leaves extracted using different solvents have not been thoroughly investigated.

METHODS

This study examined the antioxidant, antidiabetic, anticancer, and life-prolonging effects of Euonymus alatus (E. alatus) leaf extract.

RESULTS

The phytochemical analysis showed that the ethanol extract contained the highest levels of polyphenols (347.2 mg/mL) and flavonoids (317.7 mg/mL) compared to the water and methanol extracts. In addition, specific phenolics, such as rutin, ellagic acid, and quercetin, were found in the ethanol extract. Antioxidant assays showed that the ethanol extract exhibited superior DPPH, ABTS radical, and H2O2-scavenging activities, as well as reducing power. In addition, the ethanol extract displayed strong α-glucosidase inhibitory activity in a dose-dependent manner. In cancer cell studies, the ethanol extract selectively inhibited the proliferation of MDA-MB-231 (breast) and LNCaP (prostate) cancer cells without affecting normal cells. Apoptosis induction was confirmed by nuclear condensation and increased caspase-3 activity. Furthermore, treatment with 30 mg/kg/day of the extract extended the lifespan of the tumor-bearing mice to 50 days, with no fatalities, indicating a dose-dependent protective effect.

CONCLUSIONS

E. alatus leaf ethanol extract has potential as an antioxidant, antidiabetic, anticancer, and life-prolonging agent.

Antidiabetic Potential of Black Elderberry Cultivars Flower Extracts: Phytochemical Profile and Enzyme Inhibition

Black elderberry (Sambucus nigra L.) flowers are rich in polyphenolic compounds, including chlorogenic acid and quercetin derivatives, which are known for their health benefits, particularly their antioxidant and antidiabetic properties. This study aimed to optimize the extraction conditions using the Box-Behnken model to maximize polyphenol yields from different elderberry flower cultivars and to evaluate their potential for antidiabetic action. The extracts were analyzed for their phytochemical content and assessed for enzyme inhibition, specifically targeting enzymes critical in carbohydrate digestion and glucose regulation. The anti-inflammatory activity was also assessed. Results indicated that the Black Beauty, Obelisk, and Haschberg cultivars demonstrated significant inhibition of α-glucosidase, with a high inhibitory potential against α-amylase enzymes for the Obelisk cultivar. Additionally, high chlorogenic acid content was strongly correlated with enzyme inhibition and antioxidant activity, suggesting its substantial role in glucose regulation. This study underscores the potential of elderberry flower extracts, particularly those rich in chlorogenic acid, as natural agents for managing blood glucose levels, warranting further exploration of their use in antidiabetic applications.

Exploring plant-based alpha-glucosidase inhibitors: promising contenders for combatting type-2 diabetes

OBJECTIVE

This systematic review aimed to provide comprehensive details on the α-G inhibitory potential of various bioactive compounds derived from natural sources.

METHODS

A comprehensive literature search was conducted using various databases and search engines, including Science Direct, Google Scholar, SciFinder, Web of Science, and PubMed until May, 2023.

RESULTS AND CONCLUSIONS

The enzyme alpha-glucosidase (α-G) is found in the brush border epithelium of the small intestine and consists of duplicated glycoside hydrolase (GH31) domain. It involves the conversion of disaccharides and oligosaccharides into monosaccharides by acting on alpha (1 → 4) and (1 → 6) linked glucose residue. Once absorbed, glucose enters the bloodstream and elevates postprandial glucose, which is associated with the development of type 2 Diabetes (T2D). Epidemic obesity, cardiovascular disease, and nephropathy are linked to T2D. Traditional medicinal plants with α-G inhibitory potential are commonly used to treat T2D due to the adverse effects of currently used α-G inhibitors miglitol, acarbose, and voglibose. Various bioactive compounds derived from natural sources, including lupenone, Wilforlide A, Baicalein, Betulinic acid, Ursolic acid, Oleanolic acid, Katononic acid, Carnosol, Hypericin, Astilbin, lupeol, betulonic acid, Fagomine, Lactucaxanthin, Erythritol, GP90-1B, Procyanidins, Galangin, and vomifoliol retain α-G inhibitory potential for regulating hyperglycaemia.

Pharmacophore-based 3D-QSAR modeling, virtual screening, docking, molecular dynamics and biological evaluation studies for identification of potential inhibitors of alpha-glucosidase

CONTEXT

Alpha-glucosidase enzyme is considered an important therapeutic target for controlling hyperglycemia associated with type 2 diabetes. Novel scaffolds identified as potential alpha-glucosidase inhibitors from the Maybridge library utilizing pharmacophore modeling, molecular docking and biological evaluation are reported in this manuscript.

METHOD

A total of 51 xanthone series scaffolds previously reported as alpha-glucosidase inhibitors were collected and used as training and test sets. These sets were employed to develop and validate a pharmacophore-based 3D-QSAR model with statistically meaningful results using Schrodinger software. The model showed a high F value (F, 80.1) at five component partial least square factors, a high cross-validation coefficient (Q2, 0.66) and a good correlation coefficient (R2, 0.95). Pearson correlation coefficient (r) of 0.8400 indicated a greater degree of confidence in the model. Subsequently, virtual screening was performed with PHASE module of Schrodinger software using the above model to identify novel alpha-glucosidase inhibitors, and mapped compounds were evaluated for their interactions with the protein. The X-ray co-crystallised structure of the alpha-glucosidase protein in complex with acarbose (PDB Code: 5NN8) was used for molecular docking analysis using GLIDE module and a total of eight compounds were further selected for biological evaluation. Molecular dynamics analysis using GROMACS software was performed in the active site of alpha-glucosidase protein to gain insights into binding mechanism of the four active compounds which were finally found to exhibit inhibitory activity in the biological assay.

Harnessing Phytochemicals to Regulate Catalytic Residues of Alpha-Amylase and Alpha-Glucosidase in Type 2 Diabetes

Type 2 diabetes (T2D), also known as non-insulin-dependent diabetes mellitus, represents the prevailing manifestation of diabetes, encompassing a substantial majority of cases, ~90-95%. Plant-derived antidiabetic leads are being intensively explored due to their safety and effectiveness. The main objective of the present study is to evaluate the anti-diabetic potential of the traditional formulation Karisalai Karpam through in-vitro and in-silico investigations. The in-vitro and in-silico investigation of traditional polyherbal preparation Karisalai Karpam (KK) chooranam were performed to ascertain its inhibitory potential against α-amylase and α-glucosidase enzymes along with antioxidant (DPPH and ABTS) and phytochemical analysis. The results of enzyme inhibitory activity of KK witnessed highest activity against α-glucosidase enzyme with a percentage inhibition of 84.66 ± 2.50% (IC50,187.9 ± 5.79 μg/ml) followed by moderate level of α-amylase inhibition exhibited with 72.94 ± 3.66% (IC50, 241.6 ± 9.76 μg/ml). Additionally, the strongest antioxidant activity was observed in quenching DPPH• (IC50,154.8 ± 14.53 μg/ml) and ABTS+• radicals (IC50,148.6 ± 29.74 μg/ml). The outcome of the molecular docking studies indicated that among the 17 compounds analysed, the lead such as acalyphin, apigenin, humulene, and indirubin exhibited a prominent binding affinity over the residual binding site of α-glucosidase. It's important to note that the catalytic site of the enzyme α-amylase is primarily occupied by amyrin, apigenin, arjunolic acid, β-sitosterol, geraniol, and tricetin. In conclusion, the formulation KK demonstrates robust alpha-glucosidase and alpha-amylase inhibitory activity. It's also worth noting that the formulation exhibits noteworthy antioxidant properties, which could provide additional health benefits. The binding mode and energies of the identified phytochemicals against the target enzymes further support the formulation's antidiabetic potential.

In Vitro Inhibition of Enzymes and Antioxidant and Chemical Fingerprinting Characteristics of Azara serrata Ruiz & Pav. Fruits, an Endemic Plant of the Valdivian Forest of Chile

The World Health Organization has emphasized the importance of consuming small fruits for the prevention of chronic health problems, including diabetes, cardiovascular diseases, cancer, and obesity, which are named chronic non-communicable diseases (NCDs). Azara serrata Ruiz & Pav., commonly called "aroma de Castilla", is a shrub endemic to Chile from the Salicaceae family that produces an underutilized blue-grey berry that grows wild in southern Chile. The species is widely used as a medicinal plant by the Andean communities of southern Chile. In this work, a high-resolution mass spectrometric analysis of the methanolic extract revealed several phenolic compounds for the first time in the edible berry of this endemic species. Furthermore, several glycosylated anthocyanins were detected and quantified using UHPLC coupled with UV/Vis detection and trapped ion mobility mass spectrometry (UHPLC-DAD-TIMS-TOF) for the anthocyanin-rich extract, which was prepared using an optimized anthocyanin extraction protocol. The extract proved to be active in the inhibition of several enzymes linked to NCDs, such as acetylcholinesterase, tyrosinase, amylase, lipase, and glucosidase (IC50 = 3.92 ± 0.23, 12.24 ± 0.03, 11.12 ± 0.10, 32.43 ± 0.0, and 371.6 ± 0.0 μg/mL, respectively). Furthermore, the extract concentrated in anthocyanins showed good antioxidant activity evidenced by the bleaching of the radicals DPPH and ABTS, ferric-reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC). The results show that these neglected endemic small berries can be a source of healthy phytochemicals. These Chilean berries can be used as functional food and their extracts are candidates for use as functional ingredients in naturally healthy products.

Synthesis,Antidiabetic and Antitubercular Evaluation of Quinoline-pyrazolopyrimidine hybrids and Quinoline-4-Arylamines

Two libraries of quinoline-based hybrids 1-(7-chloroquinolin-4-yl)-1H-pyrazolo[3,4-d]pyrimidin-4-amine and 7-chloro-N-phenylquinolin-4-amine were synthesized and evaluated for their α-glucosidase inhibitory and antioxidant properties. Compounds with 4-methylpiperidine and para-trifluoromethoxy groups, respectively, showed the most promising α-glucosidase inhibition activity with IC50=46.70 and 40.84 μM, compared to the reference inhibitor, acarbose (IC50=51.73 μM). Structure-activity relationship analysis suggested that the cyclic secondary amine pendants and para-phenyl substituents account for the variable enzyme inhibition. Antioxidant profiling further revealed that compounds with an N-methylpiperazine and N-ethylpiperazine ring, respectively, have good DPPH scavenging abilities with IC50=0.18, 0.58 and 0.93 mM, as compared to ascorbic acid (IC50=0.05 mM), while the best DPPH scavenger is NO2-substituted compound (IC50=0.08 mM). Also, compound with N-(2-hydroxyethyl)piperazine moiety emerged as the best NO radical scavenger with IC50=0.28 mM. Molecular docking studies showed that the present compounds are orthosteric inhibitors with their quinoline, pyrimidine, and 4-amino units as crucial pharmacophores furnishing α-glucosidase binding at the catalytic site. Taken together, these compounds exhibit dual potentials; i. e., potent α-glucosidase inhibitors and excellent free radical scavengers. Hence, they may serve as structural templates in the search for agents to manage Type 2 diabetes mellitus. Finally, in preliminary assays investigating the anti-tubercular potential of these compounds, two pyrazolopyrimidine series compounds and a 7-chloro-N-phenylquinolin-4-amine hybrid showed sub-10 μM whole-cell activities against Mycobacterium tuberculosis.

Antidiabetic Activity, Phytochemical Analysis, and Acute Oral Toxicity Test of Combined Ethanolic Extract of Syzygium polyanthum and Muntingia calabura Leaves

Syzygium polyanthum is known for its capacity to regulate blood glucose levels in individuals with diabetes, while Muntingia calabura leaves have a traditional history as an alternative therapy due to their antidiabetic compounds. The combination of these two plants is expected to yield more optimized antidiabetic agents. This study aims to assess the antidiabetic activity of the combined ethanolic extract of S. polyanthum and M. calabura leaves by measuring the in vitro inhibition of the α-glucosidase enzyme and the blood glucose level in streptozotocin-induced rats and to determine the phytochemical contents of total phenolics, total flavonoids, and quercetine as marker compounds. Acute oral toxicity test was also evaluated. Both plants were extracted by maceration using 96% ethanol. Various combinations of S. polyanthum and M. calabura leaves extracts (1 : 1, 2 : 1, 3 : 1, 1 : 3, and 1 : 2) were prepared. The in vitro test, along with the total phenolic and total flavonoid content, were measured by using UV-Vis spectrophotometry, while quercetine levels were quantified through high-performance liquid chromatography (HPLC). The in vivo and acute toxicity tests were performed on rats as an animal model. The findings demonstrated that the 1 : 1 combination of S. polyanthum and M. calabura leaves ethanolic extract displayed the highest enzyme inhibitory activity with IC50 value of 36.43 µg/mL. Moreover, the combination index (CI) was found <1 that indicates the synergism effect. This combination also decreases the blood glucose level in rats after 28 days of treatments without significant difference with positive control glibenclamide (p > 0.005), and it had medium lethal doses (LD50) higher than 2000 mg/kg BW. Phytochemical analysis showed that the levels of total phenolics, total flavonoids, and quercetine were 30.81% w/w, 1.37% w/w, and 3.25 mg/g, respectively. These findings suggest the potential of combined ethanolic extracts of S. polyanthum and M. calabura leaves (1 : 1) as raw materials for herbal antidiabetic medication.

Insights into the phytochemical profiling, antidiabetic and antioxidant potentials of Lepionurus sylvestris Blume extract in fructose/streptozotocin-induced diabetic rats

In this study, the antidiabetic activities of Lepionurus sylvestris Blume extract (LSB) in rats was investigated. The in vitro antidiabetic properties of LSB was evaluated using α-amylase, α-glucosidase and DPP-IV inhibitory assays, while the antioxidant assay was analysed using DPPH, ABTS and FRAP assays. Type 2 diabetes was with high-fructose/streptozotocin, and the diabetic animals were treated with LSB for 5 weeks. At the end of the experiment, the effects of LSB were evaluated via insulin level, lipid profile and hepatorenal function biomarkers. The level of oxido-inflammatory parameters, histopathology and insulin immunohistochemical staining in the pancreas was evaluated. Diabetic rats manifested significant increases in the blood glucose level, food/water intake, lipid profiles, hepatorenal function biomarkers, as well as a marked decreases in the body weight and serum insulin levels. Histopathological and insulin immunohistochemical examination also revealed decreased pancreatic beta cells and insulin positive cells, respectively. These alterations were associated with significant increases in malondialdehyde, TNF-α and IL-1β, in addition to significant declines in GSH, SOD and CAT activities. LSB significantly reduced blood glucose level, glucose intolerance, serum lipids, restored altered hepatorenal and pancreatic functions in the treated diabetic rats. Further, LSB showed antioxidant and anti-inflammatory activities by reducing malondialdehyde, TNF-α, IL-1β, and increasing antioxidant enzymes activities in the pancreatic tissues. A total of 77 secondary metabolites were tentatively identified in the UPLC-Q-TOF-MS analysis of LSB. Overall, these findings provides insight into the potentials of LSB as an antidiabetic agent which may be associated to the plethora bioactive compounds in the plant.

Hypoglycemic Ability of Sericin-Derived Oligopeptides (SDOs) from Bombyx mori Yellow Silk Cocoons and Their Physiological Effects on Streptozotocin (STZ)-Induced Diabetic Rats

Patients with diabetes require daily medication to maintain blood sugar levels. Nevertheless, the long-term use of antidiabetics can lose efficacy and cause degeneration in some patients. For long-term diabetes care, integrating natural dietary foods and medicine is being considered. This study investigated the impact of SDOs on blood sugar levels and their physiological effects on diabetic rats. We induced diabetes in male Wistar rats with STZ (50 mg/kg) and then administered an oral glucose tolerance test to determine the SDO dosage comparable to glibenclamide. The rats were divided into nine groups: normal, diabetic, and diabetic with insulin (10 U/kg), glibenclamide (0.6 mg/kg), bovine serum albumin (BSA; 200 mg/kg), soy protein isolate (200 mg/kg), or SDOs (50, 100, and 200 mg/kg). Diabetic rats administered SDOs had a higher body weight and serum insulin but a lower blood sugar than diabetic control rats. Biochemical assays indicated lower AST/SGOT, ALT/SGPT, BUN, and triglycerides but higher HDL in the SDO groups. Immunohistochemistry showed that SDOs reduced damaged islet cells, increased beta-cell size, and improved insulin levels while decreasing alpha cell size and glucagon. The vascular effects of SDOs were like those of normal control treatment and insulin treatment in diabetic rats. SDOs, a yellow silk protein, show potential for long-term diabetes care.

Repurposing phytochemicals of Citrullus colocynthis against maltase-glucoamylase using molecular docking, MMGBSA, MD simulation and linear regression to identify potential anti-diabetic compounds

Diabetes is a common lifestyle disorder found in populations of different age groups. Maltase-glucoamylase catalyses the release of the glucose molecule in the final enzymatic reaction of starch digestion; therefore, inhibition of maltase-glucoamylase is one of the approaches in the development of therapeutics for diabetes. Citrullus colocynthis is commonly recommended in Ayurveda for the treatment of diabetes. The current study applied a structure-based drug design approach to repurpose the phytochemicals of Citrullus colocynthis to identify potential inhibitors for maltase-glucoamylase. 70 phytochemicals of Citrullus colocynthis were screened against maltase-glucoamylase and top 5 molecules 8-p-hydroxybenzylisovitexin, isoorientin, cucurbitacin B, cucurbitacin E, and cucurbitacin I with significant binding energy of -10 kcal/mol, -9.9 kcal/mol, -9.6 kcal/mol, -9.2 kcal/mol, and -7.7 kcal/mol were identified. Furthermore, MMGBSA, pharmacokinetics properties and toxicity prediction were performed on the five identified molecules and top 3 molecules were selected for molecular dynamics (MD) simulation. It was observed from the structural flexibility and dynamic behaviour of the systems that conformational changes were noticed in the complexes as compared to its native state, which suggests that the 3 molecules, namely 8-p-hydroxybenzylisovitexin, isoorientin, and cucurbitacin I of Citrullus colocynthis may act as inhibitors for maltase-glucoamylase.Communicated by Ramaswamy H. Sarma.

Phytochemistry, nutritional composition, health benefits and future prospects of Mespilus germanica L. (Medlar): A review

Mespilus germanica L., commonly known as medlar, is one of two species of the Rosaceae family. The medlar plant has a long history of use in gastronomy and healthcare. Medlar waste is used to extract hazardous heavy metals from contaminated water. The nutritional value of M. germanica fruits comes from their composition of carbohydrates, carotenoids, amino acids, organic acids, proteins, vitamins, fatty acids, and vital components. M. germanica fruit contains a high concentration of important phenolic components, which contribute to its anti-diabetic and antioxidant properties. Additionally, several studies have identified diverse biological properties of the M. germanica plant, including the cytotoxic, neurodegenerative, and antibacterial properties of its fruits and leaves. Scientists are investigating underutilized plant species to address sustainability issues in food production. This review study will provide a comprehensive examination of its chemical composition, medical applications, plant waste utilization, and potential biological activities.

Comparative study on the effects of grain blending on functional compound content and in vitro biological activity

In this study, changes in bioactive compound contents and the in vitro biological activity of mixed grains, including oats, sorghum, finger millet, adzuki bean, and proso millet, with eight different blending ratios were investigated. The total phenolic compounds and flavonoid contents ranged from 14.43-16.53 mg gallic acid equivalent/g extract and 1.22-5.37 mg catechin equivalent/g extract, respectively, depending on the blending ratio. The DI-8 blend (30% oats, 30% sorghum, 15% finger millet, 15% adzuki bean, and 10% proso millet) exhibited relatively higher antioxidant and anti-diabetic effects than other blending samples. The levels of twelve amino acids and eight organic acids in the grain mixes were measured. Among the twenty metabolites, malonic acid, asparagine, oxalic acid, tartaric acid, and proline were identified as key metabolites across the blending samples. Moreover, the levels of lactic acid, oxalic acid, and malonic acid, which are positively correlated with α-glucosidase inhibition activity, were considerably higher in the DI-blending samples. The results of this study suggest that the DI-8 blend could be used as a functional ingredient as it has several bioactive compounds and biological activities, including anti-diabetic activity.

The Browning Properties, Antioxidant Activity, and α-Glucosidase Inhibitory Improvement of Aged Oranges (Citrus sinensis)

Oranges contain many natural active chemicals, organic acids, and polysaccharides. Aging processing is commonly used to modify the color, quality, functional components, and stability of fruits. This study assesses the preparation of aging black oranges using various pre-treatments and solid fermentation. Oranges were aged for six weeks in fresh, non-blanching, blanching, and hot air-assisted aging cycle (AA) groups. The oranges' shrinkage ratio, color difference values, and soluble solids content changed significantly (p < 0.05). Principal component analysis indicated that aging fermentation treatment accelerated glycolysis and increased the ratio of reducing sugars. The enhanced browning can be associated with the oxidation of ascorbic acid (0.66-0.47 mg/g) and the formation of 5-hydroxymethylfurfural (5-HMF) (0.09 mg/g). Furthermore, the presence of free polyphenols led to an increase in the total polyphenol and total flavonoid content. It also had a synergistic effect with 5-HMF in increasing the 2,2-diphenyl-1-picrylhydrazyl free radical-scavenging capacity and ferric ion-reducing antioxidant power (p < 0.05). AA had superior α-glucosidase inhibitory ability increasing from 67.31 to 80.48%. It also reduced the development time by 33%. Therefore, aging technology can enhance the bioactive compounds in oranges and provide a reference for future whole-fruit aging fermentation and health product creation.

Albadri A, Patel H, Kadri A, Aouadi K. Identification of dual-target isoxazolidine-isatin hybrids with antidiabetic potential: Design, synthesis, in vitro and multiscale molecular modeling approaches

In the development of novel antidiabetic agents, a novel series of isoxazolidine-isatin hybrids were designed, synthesized, and evaluated as dual α-amylase and α-glucosidase inhibitors. The precise structures of the synthesized scaffolds were characterized using different spectroscopic techniques and elemental analysis. The obtained results were compared to those of the reference drug, acarbose (IC50 = 296.6 ± 0.825 μM for α-amylase & IC50 = 780.4 ± 0.346 μM for α-glucosidase). Among the title compounds, 5d exhibited impressive α-amylase and α-glucosidase inhibitory activity with IC50 values of 30.39 ± 1.52 μM and 65.1 ± 3.11 μM, respectively, followed by 5h (IC50 = 46.65 ± 2.3 μM; IC50 = 85.16 ± 4.25 μM) and 5f (IC50 = 55.71 ± 2.78 μM; IC50 = 106.77 ± 5.31 μM). Mechanistic studies revealed that the most potent derivative 5d bearing the chloro substituent attached to the oxoindolin-3-ylidene core, and acarbose, are a competitive inhibitors of α-amylase and α-glucosidase, respectively. Structure activity relationship (SAR) was examined to guide further structural optimization of the most appropriate substituent(s). Moreover, drug-likeness qualities and ADMET prediction of the most active analogue, 5d was also performed. Subsequently, 5d was subjected to molecular docking and dynamic simulation during the progression of 120 ns analysis to check the essential ligand-receptor patterns, and to estimate its stability. In silico studies were found in good agreement with the in vitro enzymatic inhibitions results. In conclusion, we demonstrated that most potent compound 5d could be exploited as dual potential inhibitor of α-amylase and α-glucosidase for possible management of diabetes.

Network pharmacology based pharmacokinetic assessment and evaluation of the therapeutic potential of catechin derivatives as a potential myostatin inhibitor: A special view on Sarcopenic Obesity

Sarcopenic obesity has become a significant age-related metabolic problem. Catechins are flavanol, derivatives which poses a strong antioxidant activity. The major components of catechin derivatives. were identified through our physicochemical and pharmacokinetic parameters estimation. Therefore, in this study, network pharmacology was used to explore the multiple targets related to Sarcopenia, Metabolic syndrome, and obesity. The targets were identified from network analysis. The catechin derivatives were screened using Lipinski's rule of five, Veber scale, Egan scale, and Muegge scale. From this drugglikness property catechin and Epicatechin was selected which were docked towards the myostatin inhibition PDB ID: 3HH2. Furthermore, the computational docking method on Catechin and Epicatechin with the stronger interaction towards myostatin inhibition receptor with the binding energy of -6.90 kcal/mol. and -7.0 kcal/mol from autodock software, respectively, for catechin and Epicatechin. Higher binding energy confirms the pharmacotherapeutic activity of Catechin and Epicatechin toward the myostatin inhibitor target.

α-Glucosidase Inhibitory Activity and Cytotoxicity of CeO2 Nanoparticles Fabricated Using a Mixture of Different Cerium Precursors

A mixture of three distinct cerium precursors (Ce(NO3)3·6H2O, CeCl3·7H2O, and Ce(CH3COO)3·H2O) was used to prepare cerium oxide nanoparticles (CeO2 NPs) in a polyol-mediated synthesis. Different ratios of diethylene glycol (DEG) and H2O were utilized in the synthesis. The properties of the synthesized CeO2 NPs, such as structural and morphological properties, were investigated to observe the effect of the mixed cerium precursors. Crystallite sizes of 7-8 nm were obtained for all samples, and all synthesized samples were confirmed to be in the cubic phase. The average particle sizes of the spherical CeO2 were between 9 and 13 nm. The successful synthesis of CeO2 can also be confirmed via the vibrational band of Ce-O from the FTIR. Antidiabetic properties of the synthesized CeO2 NPs were investigated using α-glucosidase enzyme inhibition assay, and the concentration of the synthesized CeO2 NPs was varied in the study. The biocompatibility properties of the synthesized CeO2 NPs were investigated via cytotoxicity tests, and it was found that all synthesized materials showed no cytotoxic properties at lower concentrations (62.5-125 μg/mL).

Anti-diabetic and anti-urease inhibition potential of Amomum dealbatum Roxb. seeds through a bioassay-guided approach

Using HPLC-PDA and HRMS analysis, five compounds p-coumaric acid, sinapic acid, quercetin, trans-ferulic and gallic acid were identified in seeds of Amomum dealbatum Roxb. The GC-MS analysis identified 1-dodecanol, phenol, 3,5-bis(1,1-dimethylethyl), Oleic Acid and 1-Heptacosanol which possess anti-diabetic properpties. A bioassay-guided technique was used to determine the degree of inhibition that A. dealbatum seeds crude methanol extract and its most active sub-fraction had against the α-glucosidase and Helicobacter pylori urease enzymes. In the Rat L6 myoblast cell line, glucose absorption through the GLUT4 transporter of most active subfraction (EASF80) was examined. According to a molecular docking investigation, these compounds strongly interacted with the GLUT4 transporter, H pylori and α-glucosidase enzyme. Sinapic acid interacted most strongly with the H. pylori urease enzyme while gallic acid interacted with both the α-glucosidase enzyme and the GLUT4 transporter. Additionally, a molecular docking simulation study was carried out to recognise the stability of the complexes.

Integrated transcriptome and metabolome revealed the drought responsive metabolic pathways in Oriental Lily (Lilium L.)

Objective

Lily is an essential ornamental flowering species worldwide. Drought stress is a major constraint affecting the morphology and physiology and lily leaves and flowers. Therefore, understanding the molecular mechanism underlying lily response to drought stress is important.

Method

Transcriptome and metabolome analysis were performed on Oriental Lily subjected to drought stress.

Result

Most transcription factors and metabolites yielded by the conjoint analysis displayed a downregulated expression pattern. Differential genes and metabolites mainly co-enriched in glycolic pathways related to sugars, such as galactose, and sucrose, glycolysis and gluconeogenesis, indicating that drought stress reduced the sugar metabolism level of Oriental Lily. Combined with transcriptome and metabolome data, nine pairs of differentially expressed metabolites and the genes (p < 0.05) were obtained. Interestingly, a gene named TRINITY_DN2608 (encoding a type of alpha-D-glucose) cloned and its overexpression lines in Arabidopsis thaliana was generated. Overexpression of TRINITY_DN2608 gene elevated the susceptibility to drought stress possibly by suppressing the glucose level.

Conclusion

The enrichment of sugar-related pathways advocates the potential role of glucose metabolism in drought stress. Our study provides theoretical information related to the glucose-mediated drought response and would be fruitful in future lily breeding programs.

Phytochemical profiling, human insulin stability and alpha glucosidase inhibition of Gymnema latifolium leaves aqueous extract: Exploring through experimental and in silico approach

Diabetes mellitus Type 2 (DM2T) is a rapidly expanding metabolic endocrine disorder worldwide. It is caused due to inadequate insulin secretion by pancreatic beta cells as well as development of insulin resistance. This study aimed to investigate the anti-α-glucosidase, insulin stabilization effect, and non-cytotoxic nature of Gymnema latifolium leaf aqueous extract (GLAE). FTIR analysis revealed the functional groups of compounds present in GLAE. Through LC/ESI-MS/MS analysis, about 12 compounds which belongs to different classes, triterpene glycosides, flavonoids, phenolics, stilbene glycosides and chlorophenolic glycosides were identified. GLAE showed in vitro antioxidant activity. GLAE stabilized insulin by increasing its α-helical content. GLAE inhibited the mammalian α-glucosidase (IC50 = 144 μg/mL) activity through competitive mode (Ki = 61.30 µg/mL). GLAE did not affect the viability of normal cell line (Vero cell line) which shows its non-toxic nature. Molecular docking of phytocompounds identified in GLAE was done with human α-glucosidase and insulin. The top 2 compounds [Gymnema saponin V (GSV) and quercetin 3-(2-galloylglucoside) (QGG) with α-glucosidase; GSV and Z)-resveratrol 3,4'-diglucoside (RDG) with human insulin] with low binding free energy were subjected to 100 ns molecular dynamics simulation to ascertain the stable binding of ligand with protein. The MM/GBSA analysis revealed binding free energy of GSV/α-glucosidase and QGG /α-glucosidase to be - 20.9935 and, - 30.9461 kcal/mol, respectively. Altogether GLAE is valuable source of anti-α-glucosidase inhibitors and insulin stabilizing compounds, suggesting potential lead for further exploration as complementary medicine against DM2T.

Antioxidant and α-glucosidase inhibitory activities of compound isolated from Stachytarpheta jamaicensis (L) Vahl. leaves

Stachytarpheta jamaicensis is one of the folk medicines used for the treatment of diabetes in Ambon, Indonesia, but there are limited studies on the bioactivities of its constituents. This study aims to assess the antioxidant and antidiabetic activities of four extracts of S. jamaicensis leaves extracted using several solvents. Bioassay guided fractionation on each extract establishes for exploring S. jamaicensis leaves active compounds. The antioxidant was evaluated using the DPPH and ABTS methods, while the α-glucosidase inhibitory was carried out in vitro assay. The results showed that the methanol extract of S. jamaicensis leaves displays inhibition of DPPH, ABTS and α-glucosidase activity compared to other solvent extracts. Furthermore, 6β-hydroxyipolamiide was successfully isolated from the methanol extract of S. jamicensis leaves which was reported to have α-glucosidase inhibitory activity with an IC50 of 539.17 μg/mL. Based on the results, S. jamaicensis could be recommended as an antioxidant and antidiabetic agent.

New anti-α-Glucosidase and Antioxidant Ingredients from Winery Byproducts: Contribution of Alkyl Gallates

Wine-making activity entails the production of solid and semisolid byproducts (grape stems and pomace and wine lees) that negatively impact the environment and industrial sustainability. Their features as sources of bioactive compounds support valorization procedures for functional and healthy ingredients. This work uncovers the quantitative alkyl gallates (gallic acid esters, C1-C12) profile of fresh (freeze-dried) materials and the effect of oven-drying on their stability by UHPLC-ESI-QqQ-MS/MS. The functionality was established concerning DPPH• scavenging and antihyperglycemic power. Wine lees exerted the highest high-free concentration of galloyl derivatives, ethyl gallate being the most abundant ester (3472.62 ng/g dw, on average). About the impact of the stabilization process, although as a general trend, the thermal treatment reduced the concentration, the reduction dimensions depended on the compound/matrix, remaining in valuable concentrations. Concerning radical scavenging, ze-dried stems and pomace displayed the highest capacity (24.11 and 18.46 mg TE/g dw, respectively), being correlated with propyl gallate (r2 = 0.690), butyl gallate (r2 = 0.686), and octyl gallate (r2 = 0.514). These two matrices exerted α-glucosidase inhibitory activity (1.58 and 1.46 units/L) equivalent to that of acarbose (a recognized α-glucosidase inhibitor). The newly described bioactive phytochemicals in winery residues (galloyl esters) and their correlation with functional traits allow for envisioning valorization alternatives.

Anti-Diabetic Activity of Glycyrrhetinic Acid Derivatives FC-114 and FC-122: Scale-Up, In Silico, In Vitro, and In Vivo Studies

Type 2 diabetes (T2D) is one of the most common diseases and the 8th leading cause of death worldwide. Individuals with T2D are at risk for several health complications that reduce their life expectancy and quality of life. Although several drugs for treating T2D are currently available, many of them have reported side effects ranging from mild to severe. In this work, we present the synthesis in a gram-scale as well as the in silico and in vitro activity of two semisynthetic glycyrrhetinic acid (GA) derivatives (namely FC-114 and FC-122) against Protein Tyrosine Phosphatase 1B (PTP1B) and α-glucosidase enzymes. Furthermore, the in vitro cytotoxicity assay on Human Foreskin fibroblast and the in vivo acute oral toxicity was also conducted. The anti-diabetic activity was determined in streptozotocin-induced diabetic rats after oral administration with FC-114 or FC-122. Results showed that both GA derivatives have potent PTP1B inhibitory activity being FC-122, a dual PTP1B/α-glucosidase inhibitor that could increase insulin sensitivity and reduce intestinal glucose absorption. Molecular docking, molecular dynamics, and enzymatic kinetics studies revealed the inhibition mechanism of FC-122 against α-glucosidase. Both GA derivatives were safe and showed better anti-diabetic activity in vivo than the reference drug acarbose. Moreover, FC-114 improves insulin levels while decreasing LDL and total cholesterol levels without decreasing HDL cholesterol.

Anti-obesity potential of bioactive guided fractions of Annona squamosa linn. leaves extract: a combination of in-vitro, in-vivo and in-silico studies along with profiling of lead compounds by HPTLC MS-MSn method

The antiobesity potential of bioactive fractions derived from Annona squamosa was approached using a combination of in vitro, in silico and in-vivo studies. The study was analyzed to validate and select the potent bioactive fractions of A. squamosa leaves extract through in vitro and in vivo activities targeting obesity. The phytochemical properties of the bioactive fractions were investigated utilizing total flavonoid, total phenolic and total steroidal content. Further, in vitro antioxidant assays such as nitric oxide (NO2), DPPH, ABTS, and Hydrogen peroxide (H2O2) scavenging assays were performed whereas pancreatic lipase, Alpha-amylase and Alpha glucosidase assays were carried out for enzyme inhibition activities. The overall study revealed that fractions F2 and F3 had shown significant in vitro activities targeting obesity. The selected potent fractions (F2 and F3) were orally bio-screened for efficacy in MSG-HFD-induced obese mice at 80 mg/kg/bw. The invivo study confirmed that fractions 2 and 3 with a dose of 80 mg/kg/bw had a significant potency compared to obese control and standard for various parameters. Body weight and lipid metrics were significantly reduced, and histological examinations revealed considerable beneficial alterations in the organs of the animals. Further HPTLC MS-MSn was used to characterize and identify the major compounds in the potent bioactive fractions, which confirmed the presence of seven major compounds: Ascorbic acid, Gallic acid, Quercetin, β-sitosterol, Stigmasterol, Caffeine and Epigallocatechin gallate. An in silico model was then employed to determine the best binding activity of the identified compound towards the specific receptors targeting obesity, confirming the most effective docking score towards stigmasterol and sitosterol. The in vitro and in vivo studies of derived bioactive fractions of A. squamosa leaves extract revealed a possible therapeutic approach towards anti-obesity activity for the first time.

Effects of NO3-, Cl-, and CH3COO- anions and diethylene glycol on the morphological, structural, antidiabetic, and cell viability properties of CeO2 nanoparticles

Cerium oxide (CeO₂) nanoparticles (NPs) were synthesized using a modified conventional polyol method. The ratio of diethylene glycol (DEG) and water in the synthesis was varied, and three different cerium precursor salts (Ce(NO₃)₃, CeCl₃, and Ce(CH₃COO)₃) were used. The structure, size, and morphology of the synthesized CeO₂ NPs were studied. An average crystallite size of 13 to 33 nm was obtained from the XRD analysis. Spherical and elongated morphologies of the synthesized CeO₂ NPs were acquired. Average particle sizes in the range of 16-36 nm were obtained by varying different ratios of DEG and water. The presence of DEG molecules on the surface of CeO₂ NPs was confirmed using FTIR. Synthesized CeO₂ NPs were used to study the antidiabetic and cell viability (cell cytotoxicity) properties. Antidiabetic studies were carried out using α-glucosidase enzymes inhibition activity. CeO₂ synthesized using Ce(NO₃)₃ and CeCl₃ precursors showed approximately 40.0% α-glucosidase enzyme inhibition activity, while CeO₂ synthesized using Ce(CH₃COO)₃ showed the lowest α-glucosidase enzyme inhibition activity. Cell viability properties of CeO₂ NPs were investigated using an in vitro cytotoxicity test. CeO₂ NPs prepared using Ce(NO₃)₃ and CeCl₃ were non-toxic at lower concentrations, while CeO₂ NPs prepared using Ce(CH₃COO)₃ were non-toxic at all concentrations. Therefore, polyol-mediated synthesized CeO₂ NPs showed quite good α-glucosidase inhibition activity and biocompatibility.

Chemical Composition of the Cinnamomum malabatrum Leaf Essential Oil and Analysis of Its Antioxidant, Enzyme Inhibitory and Antibacterial Activities

Cinnamomum species are a group of plants belonging to the Lauraceae family. These plants are predominantly used as spices in various food preparations and other culinary purposes. Furthermore, these plants are attributed to having cosmetic and pharmacological potential. Cinnamomum malabatrum (Burm. f.) J. Presl is an underexplored plant in the Cinnamomum genus. The present study evaluated the chemical composition by a GC-MS analysis and antioxidant properties of the essential oil from C. malabatrum (CMEO). Further, the pharmacological effects were determined as radical quenching, enzyme inhibition and antibacterial activity. The results of the GC-MS analysis indicated the presence of 38.26 % of linalool and 12.43% of caryophyllene in the essential oil. Furthermore, the benzyl benzoate (9.60%), eugenol (8.75%), cinnamaldehyde (7.01%) and humulene (5.32%) were also present in the essential oil. The antioxidant activity was indicated by radical quenching properties, ferric-reducing potential and lipid peroxidation inhibition ex vivo. Further, the enzyme-inhibitory potential was confirmed against the enzymes involved in diabetes and diabetic complications. The results also indicated the antibacterial activity of these essential oils against different Gram-positive and Gram-negative bacteria. The disc diffusion method and minimum inhibitory concentration analysis revealed a higher antibacterial potential for C. malabatrum essential oil. Overall, the results identified the predominant chemical compounds of C. malabatrum essential oil and its biological and pharmacological effects.

Recent advances on natural depsidones: sources, biosynthesis, structure-activity relationship, and bioactivities

Depsidones are a class of polyphenolic polyketides that have been proposed to be biosynthesized from oxidative coupling of esters of two polyketidic benzoic acid derivatives. They are principally encountered in fungi and lichens. In addition to their diversified structural features, they revealed varied bioactivities such as antimicrobial, antimalarial, cytotoxic, anti-inflammatory, anti-Helicobacter pylori, antimycobacterial, antihypertensive, anti-diarrheal, antidiabetic, phytotoxic, anti-HIV, anti-osteoclastogenic, and butyrylcholinesterase, tyrosinase, hyaluronidase, and acetylcholinesterase inhibition. The current work was targeted to provide an overview on the naturally reported depsidones from various sources in the period from 2018 to the end of 2022 including their structures, biosynthesis, sources, and bioactivities, as well as the reported structure-activity relationship and semisynthetic derivatives. A total of 172 metabolites with 87 references were reviewed. The reported findings unambiguously demonstrated that these derivatives could be promising leads for therapeutic agents. However, further in-vivo evaluation of their potential biological properties and mechanistic investigations are needed.

Antidiabetic and antioxidant activities of Mitragyna speciosa (kratom) leaf extract in type 2 diabetic rats

Mitragyna speciosa is a medicinal plant with a reputation for treating pains, diabetes as well as increasing energy and sexual desires. However, there is no scientific evidence to validate the antidiabetic effect of M. speciosa. This study investigated the antidiabetic effects of M. speciosa (Krat) ethanolic extract on fructose and streptozocin (STZ)-induced type 2 diabetic rats. In vitro antioxidant and antidiabetic effects were evaluated using DPPH, ABST, FRAP and α-glucosidase inhibitory assays. Rats with fructose/STZ induced T2D were treated with Krat (100 and 400 mg/kg) or metformin (200 mg/kg) for 5 weeks via oral gavage. Krat showed good antioxidant activity and also displayed potent α-glucosidase inhibitory activity. Administration of Krat to the diabetic rats significantly improved body weight gain, restored alterations in blood glucose level, glucose tolerance, dyslipidemia (increased cholesterol, triglycerides, low-density lipoprotein-cholesterol and reduced high-density lipoprotein), hepatorenal biomarkers alterations (alanine transaminase, aspartate transaminase, alanine phosphatase, creatinine and blood urea nitrogen) and oxidative stress indices (superoxide dismutase, glutathione and malondialdehyde)in the treated diabetic rats. Furthermore, Krat also restored pancreatic histological and increased immunohistochemical aberrations in the diabetic rats. These results for the first time demonstrated the antidiabetic and antihyperlipidemic potentials of M. speciosa, thus providing scientific reinforcement for the traditional use of the plant in the treatment of diabetes.

Effect of Hot- and Cold-Water Treatment on Broccoli Bioactive Compounds, Oxidative Stress Parameters and Biological Effects of Their Extracts

The goal of this work was to define resistant and susceptible variables of young broccoli (Brassica oleracea L. convar. botrytis (L.) Alef. var. cymosa Duch.) plants treated with cold and hot water. Additionally, we wanted to single out variables that could potentially be used as biomarkers of cold/hot-water stress in broccoli. Hot water changed more variables (72%) of young broccoli than cold water (24%) treatment. Hot water increased the concentration of vitamin C for 33%, hydrogen peroxide for 10%, malondialdehyde for 28%, and proline for 147%. Extracts of broccoli stressed with hot water were significantly more efficient in the inhibition of α-glucosidase (65.85 ± 4.85% compared to 52.00 ± 5.16% of control plants), while those of cold-water-stressed broccoli were more efficient in the inhibition of α-amylase (19.85 ± 2.70% compared to 13.26 ± 2.36% of control plants). Total glucosinolates and soluble sugars were affected by hot and cold water in an opposite way, which is why they could be used as biomarkers of hot/cold-water stress in broccoli. The possibility of using temperature stress to grow broccoli enriched with compounds of interest to human health should be further investigated.

Antidiabetic activity of Anredera cordifolia (Ten.) Stennis extracts with different ethanol percentages: an evaluation based on in vitro, in vivo, and molecular studies

Anredera cordifolia (Ten.) Stennis, also known as Binahong (B), is an Indonesian plant used to treat diabetes. The purpose of this study was to determine the best extragent for preparing Binahong extract as an antidiabetic agent using different concentrations of ethanol (50%, 70%, and 96%), labelled as BE50%, BE70%, and BE96%. An alpha-glucosidase inhibiting assay was used to assess the activity. The most active extract was tested in vivo assay using an oral glucose tolerance test (OGTT) and alloxan-high feed diet (alloxan-HFD)-induced diabetes in rats, with glucose level and beta cell Langerhans repair as parameters. A molecular assay was also performed to look into the expression of homeostasis regulator genes on 3T3-L1 adipose cells. The results showed that 96% ethanol extract (BE96%) inhibited alpha-glucosidase the most effectively (IC50 119.78± 11.14 μg/mL). The in vivo assay revealed that the treatment BE96% at 250 mg/kg BW for 21 consecutive days significantly reduced plasma glucose levels in Type 2 DM rats compared to the control group (p ≤ .05) with improved of Langerhans beta cells. BE96% also significantly reduced postprandial glucose levels. At the cellular level, Oil-Red-O staining revealed that differentiated adipocytes treated with BE96% had the highest lipid absorbance (p ≤ .05), compared to the control. BE96% significantly increased the expression of Glucose Transporter Isoform 4 (GLUT4) at the molecular level. It could be concluded that BE96% exhibited the best antidiabetic properties.

Development of a Thin-Layer Chromatography-Enzymatic Test Combination Method for the Isolation of α-Glucosidase Inhibitors From Thymelaea hirsuta

A rapid, easy and simple method for the isolation and purification of α-glucosidase inhibitors of the ethyl acetate extract of Thymelaea hirsuta (EaTh) by a combination of thin layer chromatography (TLC) and enzymatic test has been developed. EaTh was demonstrated previously a potent α-glucosidase inhibitory effect. In this study, we developed a simple TLC-enzymatic test (TLC/EZ) combination to isolate α-glucosidase inhibitors present in EaTh.EaTh was extracted by Soxhlet from Thymelaea hirsuta (T. hirsuta). The EaTh was separated on a silica gel column and then on a TLC plate. After TLC separation, the TLC/EZ combination method was applied. α-glucosidase inhibitors were detected directly in the TLC plate using the glucose oxidase peroxidase method (GOD-POD). A good detection of active compounds was obtained in the TLC favoring the TLC/EZ method. Active compounds were then characterized using high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis. The main α-glucosidase inhibitors present in EaTh have a molecular ion [M + H]+ at m/z = 543. This proposed method is suitable for a reliable isolation and purification of α-glucosidase inhibitors present in EaTh. It could be proposed as an interesting alternative of the classical method for the isolation and purification of α-glucosidase inhibitors in plant extracts.

Prediction of α-Glucosidase Inhibitory Activity of LC-ESI-TQ-MS/MS-Identified Compounds from Tradescantia pallida Leaves

Diabetes is a chronic disease that leads to abnormal carbohydrate digestion and hyperglycemia. The long-term use of marketed drugs results in secondary infections and side effects that demand safe and natural substitutes for synthetic drugs. The objective of this study is to evaluate the antidiabetic potential of compounds from the leaves of Tradescantia pallida. Thirteen phenolic compounds were identified from the ethyl acetate fraction of leaves of Tradescantia pallida using liquid chromatography-mass spectrometry. The compounds were then studied for the type of interactions between polyphenols and human α-glucosidase protein using molecular docking analysis. Prime Molecular Mechanics/Generalized Born Surface Area (MM-GBSA) calculations were performed to measure the binding free energies responsible for the formation of ligand-protein complexes. The compounds were further investigated for the thermodynamic constraints under a specified biological environment using molecular dynamic simulations. The flexibility of the ligand-protein systems was verified by Root Mean Square Deviation (RMSD), Root Mean Square Fluctuation (RMSF) and molecular interactions. The results authenticated the antidiabetic potential of polyphenols identified from the leaves of Tradescantia pallida. Our investigations could be helpful in the design of safe antidiabetic agents, but further in vitro and in vivo investigations are required.

Analysis of Isoflavones in Pueraria by UHPLC-Q-Orbitrap HRMS and Study on α-Glucosidase Inhibitory Activity

Pueraria is a rich source of bioactive compounds, but there is a lack of comprehensive information concerning its composition. Therefore, a UHPLC-Q-Orbitrap HRMS method was developed to identify and quantify bioactive compounds in pueraria. Twelve isoflavones were quantified, with puerarin being the most abundant, followed by puerarin 6″-O-xyloside, 3′-methoxy puerarin, and 3′-hydroxy puerarin. A further 88 bioactive components in eight categories were also tentatively identified. The 12 isoflavones, except for genistein, exhibited α-glucosidase inhibitory activity. The binding of these compounds to the active site of α-glucosidase was confirmed via molecular docking analysis. These findings provide a basis for identifying pueraria as a promising functional food ingredient.

Semisynthetic Derivatives of Pentacyclic Triterpenes Bearing Heterocyclic Moieties with Therapeutic Potential

Medicinal plants have been used by humans since ancient times for the treatment of various diseases and currently represent the main source of a variety of phytocompounds, such as triterpenes. Pentacyclic triterpenes have been subjected to numerous studies that have revealed various biological activities, such as anticancer, antidiabetic, anti-inflammatory, antimicrobial, and hepatoprotective effects, which can be employed in therapy. However, due to their high lipophilicity, which is considered to exert a significant influence on their bioavailability, their current use is limited. A frequent approach employed to overcome this obstacle is the chemical derivatization of the core structure with different types of moieties including heterocycles, which are considered key elements in medicinal chemistry. The present review aims to summarize the literature published in the last 10 years regarding the derivatives of pentacyclic triterpenes bearing heterocyclic moieties and focuses on the biologically active derivatives as well as their structure-activity relationships. Predominantly, the targeted positions for the derivatization of the triterpene skeleton are C-3 (hydroxyl/oxo group), C-28 (hydroxyl/carboxyl group), and C-30 (allylic group) or the extension of the main scaffold by fusing various heterocycles with the A-ring of the phytocompound. In addition, numerous derivatives also contain linker moieties that connect the triterpenic scaffold with heterocycles; one such linker, the triazole moiety, stands out as a key pharmacophore for its biological effect. All these studies support the hypothesis that triterpenoid conjugates with heterocyclic moieties may represent promising candidates for future clinical trials.

Critical Assessment of In Vitro Screening of α-Glucosidase Inhibitors from Plants with Acarbose as a Reference Standard

Postprandial hyperglycemia is treated with the oral antidiabetic drug acarbose, an intestinal α-glucosidase inhibitor. Side effects of acarbose motivated a growing number of screening studies to identify novel α-glucosidase inhibitors derived from plant extracts and other natural sources. As "gold standard", acarbose is frequently included as the reference standard to assess the potency of these candidate α-glucosidase inhibitors, with many outperforming acarbose by several orders of magnitude. The results are subsequently used to identify suitable compounds/products with strong potential for in vivo efficacy. However, most α-glucosidase inhibitor screening studies use enzyme preparations obtained from nonmammalian sources (typically Saccharomyces cerevisiae), despite strong evidence that inhibition data obtained using nonmammalian α-glucosidase may hold limited value in terms of identifying α-glucosidase inhibitors with actual in vivo hypoglycemic potential. The aim was to critically discuss the screening of novel α-glucosidase inhibitors from plant sources, emphasizing inconsistencies and pitfalls, specifically where acarbose was included as the reference standard. An assessment of the available literature emphasized the cruciality of stating the biological source of α-glucosidase in such screening studies to allow for unambiguous and rational interpretation of the data. The review also highlights the lack of a universally adopted screening assay for novel α-glucosidase inhibitors and the commercial availability of a standardized preparation of mammalian α-glucosidase.

Enzymes Inhibition and Antioxidant Potential of Medicinal Plants Growing in Oman

The recent study was designed to explore Dodonaea viscosa, Juniperus excelsa, Helianthemum lippii, and Euryops pinifolius using methanolic (MeOH) extract. Their subfractions were examined against urease, carbonic anhydrase II (CA-II), α-glucosidase enzymes, and free radicals scavenging significance based on local practices via standard methods. Significance potential against the urease enzyme was presented by ethyl acetate fraction (EtOAc) of D. viscosa with (IC₅₀ = 125 ± 1.75 μg/mL), whereas the H. lippii (IC₅₀ = 146 ± 1.39 μg/mL) in the EtOAc was found efficient to scavenge the free radicals. Besides, that appreciable capacity was observed by the J. excelsa, D. viscosa, J. excelsa, and E. pinifolius as compared to the standard acarbose (IC₅₀ = 377.24 ± 1.14 μg/mL). Maximum significance was noticed in methanolic (MeOH) extract of J. excelsa and presented carbonic anhydrase CA-II (IC₅₀ = 5.1 ± 0.20 μg/mL) inhibition as compared to the standard (acetazolamide). We are reporting, for the first time, the CA-II inhibition of all the selected medicinal plants and α-glucosidase, urease, and antioxidant activities of the E. pinifolius. Thus, further screening is needed to isolate the promising bioactive ingredients which act as an alternative remedy to scavenge the free radicals, antiulcer, and act as a potential source to develop new antidiabetic drugs for controlling postprandial blood sugar as well as carbonic anhydrase inhibitors.

Capsicum annuum L. cv. DANGJO ameliorated hyperglycemia in type 2 diabetes animal model induced by high-fat diet and streptozotocin

In this study, it was evaluated the effect of freeze-dried powder of Capsicum annuum L. cv. DANGJO (DJ) on ameliorating hyperglycemia in type 2 diabetes rat model induced by high-fat diet (HFD) and streptozotocin (STZ). Oral administration of DJ significantly reduced non-fasting blood glucose (NFBG) and insulin levels, as well as glycated hemoglobin (HbA1c) level, a representative marker for diabetes, in HFD/STZ treated rats whereas the administration of green hot pepper (GHP) and green sweet pepper (GSP) did not show the significant effect. Quercitrin was quantified (40.97 mg/100 g of DJ) by HPLC, and administration of the same amount of quercitrin with DJ exerted the significant reduction of blood glucose level, strongly supporting that quercitrin is the key component in ameliorating the hyperglycemia of DJ in HFD/STZ treated rats. These results suggest that DJ can be considered as a potent functional food in preventing hyperglycemia in type 2 diabetes mellitus.

A review on α-glucosidase inhibitory activity of first row transition metal complexes: a futuristic strategy for treatment of type 2 diabetes

Type 2 diabetes mellitus (T2DM) is characterized by high blood glucose levels and has emerged as a controversial public health issue worldwide. The increasing number of patients with T2DM on one hand, and serious long-term complications of the disease such as obesity, neuropathy, and vascular disorders on the other hand, have induced a huge economic impact on society globally. In this regard, inhibition of α-glucosidase, the enzyme responsible for the hydrolysis of carbohydrates in the body has been the main therapeutic approach to the treatment of T2DM. As α-glucosidase inhibitors (α-GIs) have occupied a special position in the current research and prescription drugs are generally α-GIs, researchers have been encouraged to design and synthesize novel and efficient inhibitors. Previously, the presence of a sugar moiety seemed to be crucial for designing α-GIs since they can attach to the carbohydrate binding site of the enzyme mimicking the structure of disaccharides or oligosaccharides. However, inhibitors lacking glycosyl structures have also shown potent inhibitory activity and development of non-sugar based inhibitors is accelerating. In this respect, in vitro anti-α-glucosidase activity of metal complexes has attracted lots of attention and this paper has reviewed the inhibitory activity of first-row transition metal complexes toward α-glucosidase and discussed their probable mechanisms of action.

In vitro α-glucosidase inhibitory activity of Tamarix nilotica shoot extracts and fractions

α-glucosidase inhibitors represent an important class of type 2 antidiabetic drugs and they act by lowering postprandial hyperglycemia. Today, only three synthetic inhibitors exist on the market, and there is a need for novel, natural and more efficient molecules exhibiting this activity. In this study, we investigated the ability of Tamarix nilotica ethanolic and aqueous shoot extracts, as well as methanolic fractions prepared from aqueous crude extracts to inhibit α-glucosidase. Both, 50% ethanol and aqueous extracts inhibited α-glucosidase in a concentration-dependent manner, with IC₅₀ values of 12.5 μg/mL and 24.8 μg/mL, respectively. Importantly, α-glucosidase inhibitory activity observed in the T. nilotica crude extracts was considerably higher than pure acarbose (IC₅₀ = 151.1 μg/mL), the most highly prescribed α-glucosidase inhibitor on the market. When T. nilotica crude extracts were fractionated using methanol, enhanced α-glucosidase inhibitory activity was observed in general, with the highest observed α-glucosidase inhibitory activity in the 30% methanol fraction (IC₅₀ = 5.21 μg/mL). Kinetic studies further revealed a competitive reversible mechanism of inhibition by the plant extract. The phytochemical profiles of 50% ethanol extracts, aqueous extracts, and the methanolic fractions were investigated and compared using a metabolomics approach. Statistical analysis revealed significant differences in the contents of the crude extracts and fractions and potentially identified the molecules that were most responsible for these observed variations. Higher α-glucosidase inhibitory activity was associated with an enrichment of terpenoids, fatty acids, and flavonoids. Among the identified molecules, active compounds with known α-glucosidase inhibitory activity were detected, including unsaturated fatty acids, triterpenoids, and flavonoid glycosides. These results put forward T. nilotica as a therapeutic plant for type 2 diabetes and a source of α-glucosidase inhibitors.

Comparative Antioxidant, Anti-Acetylcholinesterase and Anti-α-Glucosidase Activities of Mediterranean Salvia Species

Salvia species have a cosmopolitan distribution and comprise several well-known plants valuable for pharmaceutical and food industries due to their recognized medicinal, food flavouring, and preservative properties. The present study aimed to evaluate and compare the biological activities of seven wild-growing Salvia species from the Mediterranean area (S. fruticosa, S. glutinosa, S. nemorosa, S. officinalis, S. pratensis, S. sclarea, S. verticillata). All studied ethanolic leaf extracts exhibited significant DPPH and NO radical scavenging ability, lipid peroxidation inhibition, and reducing power, as well as moderate iron-chelating properties. Together with S. officinalis and S. fruticosa, S. verticillata showed anti-acetylcholinesterase activity, while S. glutinosa was also found to possess the ability to inhibit α-glucosidase. Total flavonoid (0.37-0.90%), phenolic acid (3.55-12.44%), tannin (1.22-2.60%), and anthocyanin contents (0.03-0.08%) were determined in Salvia leaves. Rosmarinic acid was the predominant hydroxycinnamic acid in all studied sage plants, ranging from 9400 to 38,800 μg/g. The correlation study showed a strong relationship between biological activities and contents of total phenolic acids, total tannins, and rosmarinic acid, indicating their significant contribution to the efficiency of tested Salvia species. Our results highlighted Mediterranean sage plants as rich sources of potent antioxidant, neuroprotective, and hypoglycemic agents which are worthy of further research.

Anti-Diabetic Activity of Bioactive Compound Extracted from Spondias mangifera Fruit: In-Vitro and Molecular Docking Approaches

Spondias mangifera is a drupaceous fruit popular for its flavour and health advantages. There is little scientific knowledge about S. mangifera, despite its widespread usage in traditional medicine, in the North-Eastern region of India. Inhibiting the key carbohydrate hydrolysing enzymes is one of the strategies for managing diabetes. Therefore, this study studied the antioxidant and anti-diabetic properties of different fraction S. mangifera fruit extract (SMFFs) from Indian geographical origin by in vitro experimental assays and silico docking simulation studies. The ADMET prediction for active substances was also investigated using the AdmetSAR database. Based on the binding affinity/molecular interactions between phytocompounds and target enzymes, in silico investigations were done to confirm the in vitro enzymatic inhibitory capability. β-sitosterol in EtOH-F was analysed using RP-HPLC with RP-C18 column as stationary phase and photo diode array detector. The percentage of β-sitosterol was found to be 1.21% ± 0.17% of total weight of extract (w/w). S. mangifera fruit ethanolic extract had a significant inhibitory concentration of 50% against free radicals produced by ABTS (89.71 ± 2.73%) and lipid peroxidation assay (88.26 ± 2.17%) tests. Similarly, the in vitro antidiabetic test findings indicated that S. mangifera inhibited alpha-amylase (73.42 ± 2.01%) and alpha-glucosidase (79.23 ± 1.98%) enzymes dose-dependently. The maximum glycosylated Hb percentage inhibitory activity shown in the ethanolic fraction was (83.97 ± 2.88%) at 500 µg/mL. The glucose uptake of the ethanolic fraction by the yeast cell showed significant (p < 0.05) at 500 µg/mL when compared with metformin (91.37 ± 1.59%), whereas the other fraction did not show the uptake of glucose by the yeast cell at the same concentration. In the docking study, the main phytoconstituents of S. mangifera fruit, such as oleanolic acid, beta-sitosterol, and beta amyrin, show strong affinity for pancreatic α-amylase. These results imply that S. mangifera has α-amylase and α-glucosidase inhibitory properties and may be used as antidiabetic with antioxidant characteristics.

Potential for Prebiotic Stabilized Cornus mas L. Lyophilized Extract in the Prophylaxis of Diabetes Mellitus in Streptozotocin Diabetic Rats

As a systemic disease, diabetes mellitus (DM) is characterized by the disruption of many glucose metabolic pathways. Therefore, it seems critical to study new therapies to support treatment to develop therapeutic systems that can operate across a broad metabolic spectrum. The current state of knowledge indicates an essential role of the gut microbiota in the development and course of the disease. Cornus mas fruits have demonstrated a rich biological activity profile and potential for application in the treatment of DM. As part of a preliminary analysis, the activity of four cultivars of Cornus mas fruits was analyzed. The cultivar Wydubieckij was selected as having the highest activity in in vitro conditions for further prebiotic system preparation. The study aimed to develop a unique therapeutic system based, first of all, on the mechanism of α-glucosidase inhibition and the antioxidant effect resulting from the activity of the plant extract used, combined with the prebiotic effect of inulin. The obtained system was characterized in vitro in terms of antioxidant activity and enzyme inhibition capacity, and was then tested on diabetic rats. The study was coupled with an analysis of changes in the intestinal microflora. The system of prebiotic stabilized Cornus mas L. lyophilized extract with inulin offers valuable support for the prophylaxis and treatment of DM.

Biopotential of Underutilized Rosaceae Inflorescences: LC-DAD-MS Phytochemical Profiles Associated with Antioxidant, Antidiabetic, Anti-Inflammatory and Antiproliferative Activity In Vitro

The aim of this work was to assess the biopotential of the young inflorescence tissues of Prunus, Malus and Chaenomeles in order to evaluate the possibility of their application in the food industry, and to provide a polyphenolic fingerprint for their quality control. The contents of different bioactive compounds and their antioxidant capacities were spectrophotometrically measured, the main phenolic compounds were identified and quantified using LC-DAD-MS, the antidiabetic potential was determined using α-amylase and α-glucosidase inhibition assays, the anti-inflammatory potential was determined using a 5-lipoxygenase inhibition assay, and the cytotoxicity was determined by MTT assay. Using one-way ANOVA, principal component analysis, hierarchical clustering and Pearson’s correlation coefficient, the relations between the samples, and between the samples and the measured parameters, were revealed. In total, 77 compounds were identified. The concentration of sugars was low in M. purpurea, at 1.56 ± 0.08 mg/g DW. The most effective sample in the inhibition of antidiabetic enzymes and anti-inflammatory 5-lipoxygenase was C. japonica. The inhibition of α-glucosidase was strongly positively correlated with the total and condensed tannins, procyanidin dimers and procyanidin tetramer, and was very strongly correlated with chlorogenic acid. In α-amylase inhibition, C. japonica and P. serrulata ‘Kiku Shidare Zakura’ were equally efficient to the standard inhibitor, maltose. The most effective in the growth and proliferation inhibition of HepG2, HCT116 and HaCaT cells was P. avium. The results suggest Prunus, Malus and Chaenomeles inflorescences as functional food ingredients.