Exploring the In Vitro Antidiabetic Potential of Metal Oxide Nanoparticles Synthesized Using Lemongrass and Mint Formulation

Aim This study aimed to compare the antidiabetic effect of metal oxide nanoparticles (CuONPs and ZnONPs) prepared using lemongrass and mint herbal formulations. Introduction The study explores green-synthesized nanoparticles for potential applications in diabetes management, emphasizing sustainable synthesis methods, particularly zinc oxide nanoparticles (ZnONPs) and copper oxide nanoparticles (CuONPs) produced from lemongrass and mint herbal formulations. The study was prompted by the increasing importance of innovative therapeutic strategies, responding to emerging health challenges, and leveraging advancements in nanotechnology and eco-friendly practices to explore the potential of green-synthesized nanoparticles in diabetes management. Methods The methods involve herbal formulation preparation, CuONPs and ZnONPs synthesis, and UV-visible spectrophotometry for characterization. In vitro antidiabetic activity is assessed through α-amylase and β-glucosidase enzyme assays using varied nanoparticle concentrations (10-50 µL). Results Visual observations confirm successful synthesis, with distinct color changes observed in both CuONPs and ZnONPs after 24 hours. UV-visible spectrophotometry reveals absorption peaks at 440 nm and 380 nm for CuONPs and ZnONPs, respectively. In the α-amylase assay, both nanoparticles exhibit concentration-dependent inhibition, with CuONPs ranging from 40% to 77% and ZnONPs ranging from 36% to 80%. The β-glucosidase assay demonstrates similar concentration-dependent inhibition patterns, highlighting significant differences. Conclusion The study concludes that CuONPs and ZnONPs synthesis using lemongrass and mint herbal formulations show concentration-dependent antidiabetic activity. The comparative analysis underscores the need for tailored approaches based on nanoparticle composition. These findings contribute valuable insights into the therapeutic potential of green-synthesized nanoparticles, paving the way for future nanomedicine research and development in diabetes management.

Nutritional characterization of an underutilized legume Entada rheedii Spreng. seeds and validation of its folklore uses

Entada rheedii seeds are a rich source of protein (23.99% ± 0.07), starch (42.04% ± 0.05) and potassium (1670.15 ppm ± 116.732). HPTLC-UV analysis (seeds) reveals galactose in considerable amount, that is, 2.60% ± 0.008. Additionally, the species is low in fat and anti-nutrient metabolites like tannin. Interestingly, the proximates in Entada seeds was found comparable with the commonly consumed legumes like cowpea, green gram, and so on. The species exhibits promising anti-radical, anti-inflammatory and anti-diabetic activity. Data advocates the folklore use of E. rheedii seeds and can be a promising alternative source of dietary nutrition, fortified with medicinal value. Standardization and validation of scientific knowledge will bring such underutilized, low-cost legumes into daily dietary intake and are a promising source for Protein-Energy-Malnutrition.

Investigation on Anti-diabetic Efficacy of a Cucurbitaceae Food Plant from the North-East Region of India: Exploring the Molecular Mechanism through Modulation of Oxidative Stress and Glycosylated Hemoglobin (HbA1c)

BACKGROUND

The medicinal plants of the Cucurbitaceae family, such as Solena heterophylla Lour. fruits, have significant ethnobotanical value and are readily accessible in North East India.

AIMS

We conducted a study on Solena heterophylla Lour. fruits to evaluate their anti-diabetic activity in vivo, standardize their HPTLC, and profile their metabolites using LC-QTOF-MS. We aimed to explore the molecular mechanism behind their effects on oxidative stress and glycosylated hemoglobin (HbA1c).

METHODS

Firstly, the ethyl acetate fraction of Solena heterophylla Lour. fruits was standardized using Cucurbitacin B as a standard marker by conducting HPTLC evaluation. Next, we delved into analyzing metabolite profiling. In addition, the standardized fraction was utilized in an experimental study to investigate the molecular mechanism of action in an in vivo high-fat diet and a low dose of streptozotocin-induced diabetic model.

RESULTS

We have reportedly identified 52 metabolites in the ethyl acetate fraction of Solena heterophylla (EASH). In the in vitro tests, it has been observed that this extract from plants possesses notable inhibitory properties against α-amylase and α-glucosidase. Solena heterophylla fruits with high levels of Cucurbitacin B (2.29% w/w) helped lower FBG levels in animals with EASH treatment. EASH treatment reduced HbA1c levels and normalized liver lipid peroxidation and antioxidant enzyme levels. SGOT, SGPT, and SALP serum enzyme levels also returned to normal.

CONCLUSION

Based on the current evaluation, it was found that EASH exhibited encouraging hypoglycemic effects in diabetic rats induced by a low dose of STZ and high-fat diet, which warrants further investigation.

Natural Functional Beverages as an Approach to Manage Diabetes

Diabetes mellitus is a chronic disease, commonly associated with unhealthy habits and obesity, and it is becoming a serious health issue worldwide. As a result, new approaches to treat diabetes are required, and a movement towards more natural approaches is emerging. Consuming fruit and vegetables is advised to prevent diabetes since they contain several bioactive compounds. A simple and effective strategy to include them in the diets of diabetic and obese people is through beverages. This review aims to report the anti-diabetic potentials of different vegetable and fruit beverages. These functional beverages demonstrated in vitro potential to inhibit α-glucosidase and α-amylase enzymes and to improve glucose uptake. In vivo, beverage consumption showed a reduction of blood glucose, increase of insulin tolerance, improvement of lipid profile, control of obesity, and reduction of oxidative stress. This suggests the potential of vegetable- and fruit-based functional beverages to be used as a natural innovative therapy for the management of diabetes.

Metabolomic profiling and antidiabetic activity of Callerya speciosa

Callerya speciosa is a perennial edible and medicinal plant belonging to the family Fabaceae. This study was to reveal the similarities and differences between phytochemicals in different parts of C. speciosa using a combination of ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS), principal component analysis (PCA) and orthogonal projection to latent structures discriminant analysis (OPLS-DA). In addition, the anti-diabetic activity of C. speciosa extracts was explored. A total of 141 compounds were identified and 34 robustly known chemical markers were marked. PCA and heat map analyses revealed that the stems, leaves and pods had similar phytochemical compounds, while compounds in roots and flowers differed from each other and from those in the above ground parts. In addition, extracts of C. speciosa roots and flowers exhibited anti-diabetic activity, which can be applied to the development of anti-diabetic drugs.

New Insights into the Latest Advancement in α-Amylase Inhibitors of Plant Origin with Anti-Diabetic Effects

The rising predominance of type 2 diabetes, combined with the poor medical effects seen with commercially available anti-diabetic medications, has motivated the development of innovative treatment approaches for regulating postprandial glucose levels. Natural carbohydrate digestion enzyme inhibitors might be a viable option for blocking dietary carbohydrate absorption with fewer side effects than manufactured medicines. Alpha-amylase is a metalloenzyme that facilitates digestion by breaking down polysaccharides into smaller molecules such as maltose and maltotriose. It also contributes to elevated blood glucose levels and postprandial hyperglycemia. As a result, scientists are being urged to target α-amylase and create inhibitors that can slow down the release of glucose from carbohydrate chains and prolong its absorption, thereby resulting in lower postprandial plasma glucose levels. Natural α-amylase inhibitors derived from plants have gained popularity as safe and cost-effective alternatives. The bioactive components responsible for the inhibitory actions of various plant extracts have been identified through phytochemical research, paving the way for further development and application. The majority of the findings, however, are based on in vitro investigations. Only a few animal experiments and very few human investigations have confirmed these findings. Despite some promising results, additional investigation is needed to develop feasible anti-diabetic drugs based on plant-derived pancreatic α-amylase inhibitors. This review summarizes the most recent findings from research on plant-derived pancreatic α-amylase inhibitors, including plant extracts and plant-derived bioactive compounds. Furthermore, it offers insights into the structural aspects of the crucial therapeutic target, α-amylases, in addition to their interactions with inhibitors.

Phytochemical and Biological Investigation of an Indigenous Plant of Bangladesh, Gynura procumbens (Lour.) Merr.: Drug Discovery from Nature

Gynura procumbens (Lour.) Merr. (Family: Asteraceae) is a tropical Asian medicinal plant found in Thailand, China, Malaysia, Indonesia, and Vietnam. It has long been utilized to treat a variety of health concerns in numerous countries around the world, such as renal discomfort, constipation, diabetes mellitus, rheumatism, and hypertension. The chemical investigation resulted in the isolation and characterization of six compounds from the methanol (MeOH) extract of the leaves of Gynura procumbens, which were identified as phytol (1), lupeol (2), stigmasterol (3), friedelanol acetate (4), β-amyrin (5), and a mixture of stigmasterol and β-sitosterol (6). In-depth investigations of the high-resolution ¹H NMR and ¹³C NMR spectroscopic data from the isolated compounds, along with comparisons to previously published data, were used to clarify their structures. Among these, the occurrence of Compounds 1 and 4 in this plant are reported for the first time. The crude methanolic extract (CME) and its different partitionates, i.e., petroleum ether (PESF), chloroform (CSF), ethyl acetate (EASF), and aqueous (AQSF) soluble fractions, were subjected to antioxidant, cytotoxic, thrombolytic, and anti-diabetic activities. In a DPPH free radical scavenging assay, EASF showed the maximum activity, with an IC₅₀ value of 10.78 µg/mL. On the other hand, CSF displayed the highest cytotoxic effect with an LC₅₀ value of 1.94 µg/mL compared to 0.464 µg/mL for vincristine sulphate. In a thrombolytic assay, the crude methanolic extract exhibited the highest activity (63.77%) compared to standard streptokinase (70.78%). During the assay for anti-diabetic activity, the PESF showed 70.37% of glucose-lowering activity, where standard glibenclamide showed 63.24% of glucose-reducing activity.

Anti-Diabetic Activity of a Novel Exopolysaccharide Produced by the Mangrove Endophytic Fungus Penicillium janthinellum N29

Marine microorganisms often produce exopolysaccharides with novel structures and diverse biological activities due to their specific marine environment. The novel active exopolysaccharides from marine microorganisms have become an important research area in new drug discovery, and show enormous development prospects. In the present study, a homogeneous exopolysaccharide from the fermented broth of the mangrove endophytic fungus Penicillium janthinellum N29, designated as PJ1-1, was obtained. The results of chemical and spectroscopic analyses showed that PJ1-1 was a novel galactomannan with a molecular weight of about 10.24 kDa. The backbone of PJ1-1 was composed of →2)-α-d-Manp-(1→, →4)-α-d-Manp-(1→, →3)-β-d-Galf-(1→ and →2)-β-d-Galf-(1→ units with partial glycosylation at C-3 of →2)-β-d-Galf-(1→ unit. PJ1-1 had a strong hypoglycemic activity in vitro, evaluated using the assay of α-glucosidase inhibition. The anti-diabetic effect of PJ1-1 in vivo was further investigated using mice with type 2 diabetes mellitus induced by a high-fat diet and streptozotocin. The results indicated that PJ1-1 markedly reduced blood glucose level and improved glucose tolerance. Notably, PJ1-1 increased insulin sensitivity and ameliorated insulin resistance. Moreover, PJ1-1 significantly decreased the levels of serum total cholesterol, triglyceride and low-density lipoprotein cholesterol, enhanced the level of serum high-density lipoprotein cholesterol and alleviated dyslipidemia. These results revealed that PJ1-1 could be a potential source of anti-diabetic agent.

Lead modification via computational studies: Synthesis of pyrazole-containing β-amino carbonyls for the treatment of type 2 diabetes

This article describes studies on the design, synthesis, and biological evaluation of pyrazole-containing β-amino carbonyl compounds (5a-5q) as DPP-4 inhibitors and anti-diabetic agents. In contrast, mannich reactions went smoothly with bismuth nitrate (Bi (NO₃ )₃ ) catalyst in the presence of ethanol and produced pyrazole-containing β-amino carbonyl compounds in good yield. Molecular docking studies of designed derivatives with DPP-4 enzyme (PDB: 2OLE), compounds 5d, 5h, 5j, and 5k showed excellent interaction. 3D QSAR and pharmacophoric model studies were also carried out. ADMET parameters, pharmacokinetic properties, and in vivo toxicity studies further confirmed that all the designed compounds were found to have good bioavailability and were less toxic. Further, these compounds were evaluated as enzyme-based in vitro DPP-4 inhibitory activity, and 5d, 5h, 5i, 5j, and 5k exhibited IC₅₀ toward DPP-4 enzyme of 10.52, 10.41, 5.55, 4.16, and 7.5 nM, respectively. The most potent compound, 5j, was further selected for in vivo anti-diabetic activity using an STZ-induced diabetic mice model, and 5j showed a significant diabetic control effect.

Quercetin, a Plant Flavonol Attenuates Diabetic Complications, Renal Tissue Damage, Renal Oxidative Stress and Inflammation in Streptozotocin-Induced Diabetic Rats

Diabetes mellitus is a metabolic syndrome characterized by increased glucose levels, oxidative stress, hyperlipidemia, and frequently decreased insulin levels. The current research was carried out for eight consecutive weeks to evaluate the possible reno-protective effects of quercetin (50 mg/kg b.w.) on streptozotocin (STZ) (55 mg/kg b.w.) induced diabetes rat models. Various physiological, biochemical, and histopathological parameters were determined in control, diabetic control, and quercetin-treated diabetic rats. The current findings demonstrated that diabetes control rats showed significantly decreased body weights (198 ± 10 vs. 214 ± 13 g) and insulin levels (0.28 ± 0.04 vs. 1.15 ± 0.05 ng/mL) in comparison to normal control. Besides this, the other parameters showed increased values, such as fasting blood glucose, triglyceride (TG), and total cholesterol levels (99 ± 5 vs. 230 ± 7 mg/dL, 122.9 ± 8.7 vs. 230.7 ± 7.2 mg/dL, 97.34 ± 5.7 vs. 146.3 ± 8 mg/dL) (p < 0.05). In addition, the urea and creatinine levels (39.9 ± 1.8 mg/dL and 102.7 ± 7.8 μmol/L) were also high in diabetes control rats. After 8 weeks of quercetin treatment in STZ-treated animals, body weight, insulin, and fasting blood sugar levels were significantly restored (p < 0.05). The inflammatory markers (TNF-α, IL-6, and IL-1β) were significantly increased (52.64 ± 2, 95.64 ± 3, 23.3 ± 1.2 pg/mL) and antioxidant enzymes levels (SOD, GST, CAT, and GSH) were significantly decreased (40.3 ± 3 U/mg, 81.9 ± 10 mU/mg, 14.2 ± 2 U/mg, 19.9 ± 2 μmol/g) in diabetic rats. All the parameters in diabetic animals treated with quercetin were restored towards their normal values. Histopathological findings revealed that the quercetin-treated group showed kidney architecture maintenance, reduction of fibrosis, and decreased expression of COX-2 protein. These results determined that quercetin has reno-protective effects, and conclude that quercetin possesses a strong antidiabetic potential and might act as a therapeutic agent in the prevention or delay of diabetes-associated kidney dysfunction.

Essential oil composition and biological activities of Aleppo pine (Pinus halepensis Miller) needles collected from different Tunisian regions

The aim of this research was to investigate the variation regarding the chemical composition and biological activities of needles essential oils (EOs) of P. halepensis. Chemical profiles demonstrated a significant (P < 0.05) variability among the different EOs. The main identified compounds were caryophyllene (48.77 ± 2.26), phenyl isovalerate (22.22 ± 2.26), β-myrcene (15.55 ± 5.65) and α-pinene (14.52 ± 2.26). Further, it was shown that EO from Tabouba (Tab) displayed the highest DPPH scavenging (IC₅₀ = 73.03 mg/mL), anti-inflammatory (IC₅₀ = 23.29 µg/mL) and α-glucosidase inhibition activities (IC₅₀ = 254.45 µg/mL). While Elmahres (Elm) exhibited the most potent ABTS radical's inhibition (IC₅₀ = 197.87 mg/mL). For the cytotoxic capacities, Kettana (Ket) was the most efficient against breast cancer MCF-7 cell line with IC₅₀ value better than doxorubicin used as positive control. Obtained results suggest that EO of P. halepensis could be used as a source of bioactive compounds.

Network Pharmacology- and Molecular Dynamics Simulation-Based Bioprospection of Aspalathus linearis for Type-2 Diabetes Care

The medicinal herb Aspalathus linearis (rooibos) is globally recognized in type-2 diabetes mellitus (T2DM) treatment due to its known and distinctive compounds. This work utilized network pharmacology (NP) coupled with molecular dynamics simulation in gaining new insight into the anti-diabetic molecular mechanism of action of rooibos teas. It looked at the interactions between rooibos constituents with various relevant protein receptors and signaling routes associated with T2DM progression. The initial analysis revealed 197 intersecting gene targets and 13 bioactive rooibos constituents linked to T2DM. The interactions between proteins and compounds to the target matrix were generated with the Cystoscope platform and STRING database. These analyses revealed intersecting nodes active in T2DM and hypoxia-inducible factor 1 (HIF-1) as an integral receptors target. In addition, KEGG analysis identified 11 other pathways besides the hub HIF-1 signaling route which may also be targeted in T2DM progression. In final molecular docking and dynamics simulation analysis, a significant binding affinity was confirmed for key compound-protein matrices. As such, the identified rooibos moieties could serve as putative drug candidates for T2DM control and therapy. This study shows rooibos constituents' interaction with T2DM-linked signaling pathways and target receptors and proposes vitexin, esculin and isovitexin as well as apigenin and kaempferol as respective pharmacologically active rooibos compounds for the modulation of EGFR and IGF1R in the HIF-1 signaling pathway to maintain normal homeostasis and function of the pancreas and pancreatic β-cells in diabetics.

Phytochemical Investigation and Biological Studies on Selected Searsia Species

Searsia is the more recent name for the genus Rhus, which contains over 250 individual species of flowering plants in the family Anacardiaceae. Several Searsia species are used in folk medicine and have been reported to exhibit various biological activities. Although known to exhibit different terpenoids and flavonoids, the chemistry of the Searsia genus is not comprehensively studied due to the structural complexity of the compounds. In this study, the extraction, isolation, and identification of secondary metabolites from three Searsia species (Searsia glauca, S. lucida, and S. laevigata) were conducted using chromatographic and spectroscopic techniques and afforded five known terpenes, viz., moronic acid (1), 21β-hydroxylolean-12-en-3-one (2), lupeol (11), α-amyrin (9), and β-amyrin (10), in addition to six known flavonoids, myricetin-3-O-β-galactopyranoside (3), rutin (4), quercetin (5), apigenin (6), amentoflavone (7), and quercetin-3-O-β-glucoside (8). The structural elucidation of the isolated compounds was determined based on NMR (1D and 2D) and comparison with the data in the literature. Biological assays, such as antioxidant and enzyme inhibition activity assays, were conducted on the plant extracts and the isolated compounds. The antioxidant capacities of hexane, dichloromethane, ethyl acetate, methanol, and butanol main extracts were investigated using ferric ion reducing power (FRAP), oxygen radical absorbance capacity (ORAC), and Trolox equivalent antioxidant capacity (TEAC) assays. The results showed high antioxidant activities for methanol and butanol extracts of the three plants. The isolated compounds were tested against alpha-glucosidase and alpha-amylase, and the results showed the potent activity of moronic acid (C1) (IC₅₀ 10.62 ± 0.89 and 20.08 ± 0.56 µg/mL, respectively) and amentoflavone (C7) (IC₅₀ 5.57 ± 1.12 µg/mL and 19.84 ± 1.33 µg/mL, respectively). Isolated compounds of and biological assays for S. glauca, S. lucida, and S. laevigata are reported for the first time.

Synthesis, Antimicrobial and Molecular Docking studies of Some New Derivatives of 2,3-Dihydroquinazolin-4(1H)-one

In the present study a series of novel 2-(substituted phenyl)-3-(5-phenyl-1,3,4-thiadiazol-2-yl)-2,3-dihydroquinazolin-4(1H)-one derivatives were synthesized by refluxing isatoic anhydride, 5-phenyl-1,3,4-thiadiazol-2-amine and aromatic aldehydes in the presence of p-TsOH as the catalyst and in H2O as the solvent and characterized by spectroscopic data and analytical methods. Antibacterial and antifungal activity of the title compounds were evaluated against two Gram positive and two Gram negative bacterial strains and strains of fungi and compared with standard drugs, using well diffusion method minimum bactericidal/fungicidal concentration were determined. The potential α-amylase and α-glucosidase inhibitory activity of compounds 4a-l were investigated in silico using molecular docking simulation method. Therefore, these 2,3-dihydroquinazolin-4(1H)-one derivatives may be considered as promising candidates for the development of new classes of antimicrobial and antidiabetic drugs.

Flowering Plants along with In Vitro Anti-Diabetic Performance

Bombax ceiba L. (Family: Malvaceae) was rightly called the “silent doctor” in the past as every part of it had medicinal value. For centuries, humans have used this plant according to the traditional medicinal systems of China, Ayurveda, and tribal communities. Recently, with an emerging interest in herbals, attention has been paid to scientifically validating medicinal claims for the treatment of diabetes using secondary metabolites of B. ceiba L. flowers. In the present study, specific secondary metabolites from the flowers of B. ceiba L. were isolated in good yield using the solvent extraction methodology, and their in vitro anti-diabetic efficacy was examined. Extraction efficiency of each solvent for secondary metabolites was found in following order: water > ethanol> methanol > chloroform > petroleum ether. Quantitative analysis of secondary metabolites showed 120.33 ± 2.33 mg/gm polyphenols, 60.77 ± 1.02 mg/g flavonoids, 60.26 ± 1.20 mg/g glycosaponins, 0.167 ± 0.02 mg/g polysaccharides for water extract; 91.00 ± 1.00 mg/g polyphenols, 9.22 ± 1.02 mg/g flavonoids, 43.90 ± 0.30 mg/g glycosaponins, 0.090 ± 0.03 mg/g poly saccharides for ethanol extract; 52.00 ± 2.64 mg/g polyphenols, 35.22 ± 0.38 mg/g flavonoids, 72.26 ± 1.05 mg/g glycosaponins, 0.147 ± 0.01 mg/g polysaccharides for methanol extract; 11.33 ± 0.58 mg/g polyphenols, 23.66 ± 1.76 mg/g flavonoids, 32.8 ± 0.75 mg/g glycosaponins, 0.013 ± 0.02 mg/g polysaccharides for chloroform extract; and 3.33 ± 1.53 mg/g polyphenols, 1.89 ± 1.39 mg/g flavonoids, 21.67 ± 1.24 mg/g glycosaponins, 0.005 ± 0.01 mg/g polysaccharides for petroleum ether extract. Glucose uptake by yeast cells increased 70.38 ± 2.17% by water extract.

Characterization of stenocephol from Seriphidium stenocephalum as potent HepG2 cell growth and glycogen phosphorylase inhibitor

Plant-derived compounds represent an important source for developing innovative drugs. One of the widely distributed plants, especially in Afghanistan and Pakistan, Seriphidium stenocephalum, was investigated in this study to identify bioactive compounds. The plant extract was subjected to silica gel column chromatography, four phenolic acid derivatives were isolated, while stenocephol was obtained by ethyl acetate fraction. Stenocephol was subjected to experimental screening for anti-diabetic and anti-cancer activities, measuring its inhibitory potency against glycogen phosphorylase, and its cytotoxicity against HepG2 cells. Further insights into the mechanism of action of stenocephol were obtained from a computational investigation. Stenocephol showed a dose-dependent manner of inhibition against glycogen phosphorylase and HepG2 cells in the low micromolar range. Notably, coupling in vitro and computational investigation, we identified the natural product stenocephol as a possible anti-diabetic and anti-cancer agent, representing a possible starting point for developing novel therapeutics, enriching the armamentarium against the mentioned diseases.

Momordica charantia L.-Diabetes-Related Bioactivities, Quality Control, and Safety Considerations

Momordica charantia L. (Cucurbitaceae), commonly known as bitter gourd or bitter melon, is widely cultivated in many tropical and subtropical regions of the world, where its unripe fruits are eaten as a vegetable. Apart from its culinary use, M. charantia has a long history in traditional medicine, serving as stomachic, laxative or anthelmintic, and, most notably, for the treatment of diabetes and its complications. Its antidiabetic properties and its beneficial effects on blood glucose and lipid concentrations have been reported in numerous in vitro and in vivo studies, but the compounds responsible for the observed effects have not yet been adequately described. Early reports were made for charantin, a mixture of two sterol glucosides, and the polypeptide p-insulin, but their low concentrations in the fruits or their limited bioavailability cannot explain the observed therapeutic effects. Still, for many decades the search for more reasonable active principles was omitted. However, in the last years, research more and more focused on the particular cucurbitane-type triterpenoids abundant in the fruits and other parts of the plant. This mini review deals with compounds isolated from the bitter gourd and discusses their bioactivities in conjunction with eventual antidiabetic or adverse effects. Furthermore, methods for the quality control of bitter gourd fruits and preparations will be evaluated for their meaningfulness and their potential use in the standardization of commercial preparations.

Potential Effect of Polyphenolic-Rich Fractions of Corn Silk on Protecting Endothelial Cells against High Glucose Damage Using In Vitro and In Vivo Approaches

Endothelial cell dysfunction is considered to be one of the major causes of vascular complications in diabetes. Polyphenols are known as potent antioxidants that can contribute to the prevention of diabetes. Corn silk has been reported to contain polyphenols and has been used in folk medicine in China for the treatment of diabetes. The present study aims to investigate the potential protective role of the phenolic-rich fraction of corn silk (PRF) against injuries to vascular endothelial cells under high glucose conditions in vitro and in vivo. The protective effect of PRF from high glucose toxicity was investigated using human umbilical vein endothelial cells (HUVECs). The protective effect of PRF was subsequently evaluated by using in vivo methods in streptozotocin (STZ)-induced diabetic rats. Results showed that the PRF significantly reduced the cytotoxicity of glucose by restoring cell viability in a dose-dependent manner. PRF was also able to prevent the histological changes in the aorta of STZ-induced diabetic rats. Results suggested that PRF might have a beneficial effect on diabetic patients and may help to prevent the development and progression of diabetic complications such as diabetic nephropathy and atherosclerosis.

Distribution of Polyphenolic and Isoprenoid Compounds and Biological Activity Differences between in the Fruit Skin + Pulp, Seeds, and Leaves of New Biotypes of Elaeagnusmultiflora Thunb

The purpose of this study was to determine the distribution of polyphenolic and isoprenoid compounds and organic acids in the fruit skin + pulp, seeds, and leaves of six new biotypes of Elaeagnus multiflora Thunb., as well as their in vitro biological potency. The polyphenols and isoprenoids were determined with UPLC-PDA-MS/MS (ultra-performance liquid chromatography coupled to photodiode array detection and electrospray ionization tandem mass spectrometry) and RRLC-MS/MS (rapid resolution liquid chromatography/tandem mass spectrometry) methods, the organic acid with HPLC-RID (high-performance liquid chromatography coupled to a Refractive Index Detector), and the antioxidant capacity using ABTS and FRAP assays. Enzymatic activity was established as the ability to inhibit α-amylase, α-glucosidase, and pancreatic lipase. Owing to such an effective technique, 88 compounds were recorded, with 17 polyphenolic compounds and 3 isoprenoids identified for the first time in the seeds and leaves of cherry silverberry. In total, 55 compounds were identified in the leaves, 36 in the seeds, and 31 in the fruit skin + pulp. The predominant polyphenol was polymeric procyanidin (66–95% of total polyphenolics), whereas the predominant isoprenoids were chlorophyll b and (all-E)-lycopene. The results of our work noted that there are significant differences in the profiles of several secondary metabolites between the analyzed parts of the plant, and depending on the need, the compounds can be used to develop different innovative food or cosmetic products.

Synthesis, Characterization, and In Vitro Insulin-Mimetic Activity Evaluation of Valine Schiff Base Coordination Compounds of Oxidovanadium(V)

Type 2 diabetes became an alarming global health issue since the existing drugs do not prevent its progression. Herein, we aimed to synthesize and characterize a family of oxidovanadium(V) complexes with Schiff base ligands derived from L-/D-valine (val) and salicylaldehyde (sal) or o-vanillin (van) as insulin-mimetic agents and to assess their potential anti-diabetic properties. Two new oxidovanadium(V) complexes, [{VVO(R-salval)(H2O)}(μ2-O){VVO(R-salval)}] and [{VVO(R-vanval)(CH3OH)}2(μ2-O)], and their S-enantiomers were synthesized and characterized. The compounds exhibit optical activity as shown by crystallographic and spectroscopic data. The stability, the capacity to bind bovine serum albumin (BSA), the cytotoxicity against human hepatoma cell line, as well as the potential anti-diabetic activity of the four compounds are investigated. The synthesized compounds are stable for up to three hours in physiological conditions and exhibit a high capacity of binding to BSA. Furthermore, the synthesized compounds display cytocompatibility at biologically relevant concentrations, exert anti-diabetic potential and insulin-mimetic activities by inhibiting the α-amylase and protein tyrosine phosphatase activity, and a long-term increase of insulin receptor phosphorylation compared to the insulin hormone. Thus, the in vitro anti-diabetic potential and insulin-mimetic properties of the newly synthesized oxidovanadium(V) compounds, correlated with their cytocompatibility, make them promising candidates for further investigation as anti-diabetic drugs.

Metabolite Profiling of Methanolic Extract of Gardenia jaminoides by LC-MS/MS and GC-MS and Its Anti-Diabetic, and Anti-Oxidant Activities

In this study, the methanolic extract from seeds of Gardenia jasminoides exhibited strong antioxidant and enzyme inhibition activities with less toxicity to NIH3T3 and HepG2 cells at the concentration of 100 µg/mL. The antioxidant activities (DPPH and ABTS), α-amylase, and α-glucosidase inhibition activities were found higher in methanolic extract (MeOH-E) than H₂O extract. Besides, 9.82 ± 0.62 µg and 6.42 ± 0.26 µg of MeOH-E were equivalent to 1 µg ascorbic acid for ABTS and DPPH scavenging, respectively while 9.02 ± 0.25 µg and 6.52 ± 0.15 µg of MeOH-E were equivalent to 1 µg of acarbose for inhibition of α-amylase and α-glucosidase respectively. Moreover, the cell assay revealed that the addition of MeOH-E (12.5 µg/mL) increased about 37% of glucose uptake in insulin resistant (IR) HepG2 as compared to untreated IR HepG2 cells. The LC- MS/MS and GC-MS analysis of MeOH-E revealed a total of 54 compounds including terpenoids, glycosides, fatty acid, phenolic acid derivatives. Among the identified compounds, chlorogenic acid and jasminoside A were found promising for anti-diabetic activity revealed by molecular docking study and these molecules are deserving further purification and molecular analysis.

Amaranth, quinoa and chia bioactive peptides: a comprehensive review on three ancient grains and their potential role in management and prevention of Type 2 diabetes

Worldwide prevalence of Type 2 Diabetes (T2D) has become a major concern with several implications for public health, economy, and social well-being, especially in developing countries. Conventional pharmacological management of T2D have proved effective, but possess underlying side effects, leading the scientific community to research alternative compounds that exert beneficial effects on current therapeutic targets of T2D. Bioactive peptides (BAPs) from food sources, have shown relative advantages in this matter, moreover, BAPs have proved to impart anti-diabetic activity through one or more mechanisms such as enzymatic inhibition of α-glucosidase, α-amylase and DPP-IV. Several plants and animal have been used as protein sources of anti-diabetic BAPs, in the sense of this matter, the pseudo-cereals amaranth and quinoa, along with the ancestral grain chia, have gained attention. Due, to their high protein content and balanced amino-acid composition, along with proved anti-diabetic features, the three seeds are top choices for the obtention of anti-diabetic BAPs. With a comprehensive overview of the most recent reported in silico and in vitro anti-diabetic studies in relation to biomarkers α-glucosidase, α-amylase and DPP-IV, the present review aims to examine the current knowledge of amaranth, quinoa and chia derived anti-diabetic BAPs and their effects on T2D therapeutic markers.

Tylophora hirsuta (Wall.) Extracts Ameliorate Diabetes Associated with Inflammation in Alloxan-induced Diabetic Rats

BACKGROUND

Tylophora hirsuta (Wall) has long been used as traditional medicine for the treatment of diabetes. The current study is designed to evaluate the anti-diabetic and anti-inflammatory activity of different extracts of aerial parts of Tylophora hirsuta.

METHODS

Sequential maceration was conducted to obtain extracts. Total phenolic contents were determined by the Folin-Ciocalteau method. The anti-oxidant activity was assessed by DPPH free radical scavenging assay. The extracts were tested for its inhibitory activity against α-amylase in-vitro. In-vivo anti-diabetic assay was conducted using alloxan-induced diabetic model and OGTT was conducted on normal rats. ELISA was used to determine the pro-inflammatory cytokines (TNF-α and IL-6). The polyphenolic composition of the extract was analyzed using an HPLC system.

RESULTS

Aqueous extract exhibited highest total phenolic contents (985.24± 3.82 mg GAE/100 g DW), antioxidant activity (IC50 = 786.70 ± 5.23 μg/mL), and alpha-amylase inhibition (IC50 =352.8 μg/mL). The aqueous extract of Tylophora hirsuta showed remarkable in-vivo anti-diabetic activity. Results were compared with standard drug glibenclamide. Alloxan induced diabetic mediated alterations in liver function enzymes, renal function determinants, and lipid parameters were significantly restored in aqueous extract treated diabetic rats. A significant reduction in pro-inflammatory cytokines (p<0.001) was observed when compared to the control group. HPLC analysis confirms the presence of quercetin, gallic acid, cinnamic acid, and p-coumaric acid.

CONCLUSION

These results showed that Tylophora hirsuta possesses strong anti-diabetic and anti-inflammatory potentials and justify its folklore use for the management of diabetes.

Valorisation of stachysetin from cultivated Stachys iva Griseb. as anti-diabetic agent: a multi-spectroscopic and molecular docking approach

Stachys species are considered as important medicinal plants with numerous health benefit effects. In continuation of our research on the Greek Stachys species, the chemical profile of the aerial parts of cultivated S. iva Griseb. has been explored. The NMR profiles of the plant extract/infusion were used to guide the isolation process, leading to the targeted isolation of seventeen known compounds. The rare acylated flavonoid, stachysetin, was isolated for the third time from plant species in the international literature. Identification of the characteristic signals of stachysetin in the 1D ¹H-NMR spectrum of the crude extract was presented. In order to evaluate the potential of the identified chemical space in Stachys to bear possible bioactivity against diabetes, we performed an in silico screening against 17 proteins implicated in diabetes, as also ligand based similarity metrics against established anti-diabetic drugs. The results capitalized the anti-diabetic potency of stachysetin. Its binding profile to the major drug carrier plasma protein serum albumin was also explored along with its photophysical properties suggesting that stachysetin could be recognized and delivered in plasma through serum albumin and also could be tracked through near-infrared imaging. Communicated by Ramaswamy H. Sarma.

The chemistry and biological activities of Citrus clementina Hort. Ex Tanaka (Rutaceae), a vegetatively propagated species

We report the chemistry and biological activities of a Cameroonian Citrus clementina Hort. Ex Tanaka, a vegetatively propagated species. The compounds isolated from this plant were determined to be the known 5-hydroxy-6,7,8,3',4'-pentamethoxyflavone (1), tangerine (3), nobilletin (4), 5,7,8,4'-tetramethoxyflavone (5), citracridone I (6), 5-hydroxynoracronycine (7), citracridone III (8), xanthyletin (10), suberosin (9), E-suberenol (11), E-methoxysuberenol (13), 6-formylumbelliferone (12), aurantiamide acetate (2), limonin (14), stigmasterol, β-sitosterol and β-sitosterol-3-O-β-D-glucoside. The structures of the compounds were established on the basis of their NMR spectroscopic data and comparison with published data. Methanol leaf extract and compounds 1, 2, 4, 6, 7 and 10 were evaluated for their anti-inflammatory, antioxidant, urease and anti-diabetic effects. Compound 10 showed antioxidant activity, anti-inflammatory effect, urease activity and anti-diabetic activity with IC₅₀ values of 47.3 µM, 33.5 µM, 25.2 µM and 33.9 µM respectively, values that were comparable to the respective positive standards.

Polyphenol Compounds and Biological Activity of Caper (Capparis spinosa L.) Flowers Buds

The aim of the study was to analyze potential health-promoting components of caper flower buds (Capparis spinosa L.) at six stages of development in two cultivars. Polyphenol compounds (flavonols, hydroxycinnamic acids, flavan-3-ols) were identified by Liquid Chromatography- quadrupole Time-of-Flight -Mass Spectrofotometer/Mass Spectrofotometer (LC-qTOF-MS/MS) and quantified by Ultra Performance Liquid Chromatography-Photodiode Array-Fluorescence Detector (UPLC-PDA-FL). Moreover, antioxidant properties (ABTS+•, FRAP, and ORAC), anti-diabetic potential (α-amylase and α-glucosidase), and anti-aging activity (acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)) of the buds were examined. Total phenolic compounds in the investigated caper varied from 10,720 to 3256 mg/100 g dry weight (DW), and depended on a genotype and growing stage of caper flowers. Among six different growing stages, the one named 'nonpareilles' was characterized by significantly higher content of polyphenols than the remaining five stages. The flavonols in caper flowers represented a mixture of different glycosylated quercetin, kaempferol, myricetin, and isorhamnetin derivatives, accounting for 38%-67%, 15%-36%, 4%-7%, and 0.8%-3%, respectively, of total flavonols,. Their contents strongly depended on the growth stage. 'Nonpareilles' and 'surfines' were richer in flavonols than 'fines' and 'gruesas'. Of the six investigated growth stages, 'nonpareilles' accumulated the greatest amounts of bioactive compounds that correlated with antioxidant and anti-diabetic properties, and were more potent BuChE than AChE inhibitors.

Lentinus edodes Exposure before and after Fetus Implantation: Materno-Fetal Development in Rats with Gestational Diabetes Mellitus

Background: The presence of β-glucans and phenolic compounds in Lentinus edodes suggests this mushroom can be used as a nutritional supplement. Two gestational conditions (before and after fetus implantation) were evaluated, and Lentinus edodes exposure was performed in diabetes mellitus rat model induced by streptozotocin in pre-clinical tests. Methods: On the 20th day of pregnancy, cesarean sections were performed. Blood was collected for biochemical, hematologic parameters and oxidative stress biomarkers. Placenta and amniotic fluid were collected, and fetuses were analyzed through morphological evaluation. Results: The mushroom did not reduce the severe hyperglycemia of the mother-concept but promoted an increase in maternal insulin levels; reduced the levels of alanine aminotransferase, and aspartate aminotransferase, triglyceride and total cholesterol; protected the animals from post-implantation losses. Liver damage induced by streptozotocin was reversed in experimental groups. Conclusions: Lentinus edodes mushroom has antioxidant properties that can minimize the damage caused by gestational diabetes mellitus.

Two Novel Multi-Functional Peptides from Meat and Visceral Mass of Marine Snail Neptunea arthritica cumingii and Their Activities In Vitro and In Vivo

Neptunea arthritica cumingii (Nac) is a marine snail with high nutritional and commercial value; however, little is known about its active peptides. In this study, two multi-functional peptides, YSQLENEFDR (Tyr-Ser-Gln-Leu-Glu-Asn-Glu-Phe-Asp-Arg) and YIAEDAER (Tyr-Ile-Ala-Glu-Asp-Ala-Glu-Arg), were isolated and purified from meat and visceral mass extracts of Nac using a multi-bioassay-guided method and were characterized by using liquid chromatography-tandem mass spectrometry. Both peptides showed high antioxidant, angiotensin-converting enzyme (ACE)-inhibitory, and anti-diabetic activities, with half-maximal effective concentrations values less than 1 mM. Antioxidant and ACE-inhibitory activities were significantly higher for YSQLENEFDR than for YIAEDAER. In a zebrafish model, the two peptides exhibited strong scavenging ability for reactive oxygen species and effectively protected skin cells against oxidative damage without toxicity. Molecular docking simulation further predicted the interactions of the two peptides and ACE. Stability analysis study indicated that the two synthetic peptides maintained their activities under thermal stress and simulated gastrointestinal digestion conditions. The low molecular weight, high proportion of hydrophobic and negatively-charged amino acids, and specific C-terminal and N-terminal amino acids may contribute to the observed bio-activities of these two peptides with potential application for the prevention of chronic noncommunicable diseases.

Antioxidant and anti-diabetic effects of Auricularia auricular polysaccharides and their degradation by artificial gastrointestinal digestion - Bioactivity of Auricularia auricular polysaccharides and their hydrolysates

BACKGROUND

Auricularia auricular polysaccharides (AAPs) derived from the dried fruit body of A. auricular are valuable compounds with many bioactivities. This research aimed to investigate the antioxidant and anti- diabetic activities of these polysaccharides and their artificial gastrointestinal fluid hydrolysates (AAPHs).

METHODS

Artificially simulated gastrointestinal fluid was used to obtain polysaccharide-de- rived fragments, and a rat model of type 2 diabetes mellitus (T2DM) using a high-fat diet and low-dose streptozotocin (STZ) was established to assess their antioxidant and anti-diabetic effects.

RESULTS

It was found that AAPs and AAPHs were both heteropolysaccharides and were comprised of arab- inose, xylose, mannose, 2-deoxy-glucose, glucose and glucosamine, but at different mole ratios. AAPHs was purified by Sephadex G-100 chromatography to produce three fractions, namely, AAPHs1, AAPHs2, and AAPHs3. The molecular weights of these three fractions were 320, 169, and 62 kDa respectively. Both AAPs and AAPHs exhibited the evident ability to enhance the activities of antioxidant enzymes and the level of GSH, while increasing the content of liver glycogen and plasma C-peptide compared with the diabetic model group (p < 0.05). Furthermore, AAPHs could cause a marked improvement in glucose-stimulated GLP-1 secretion from 0 min to 30 min (p < 0.05).

CONCLUSIONS

The possible mechanism was that AAPHs could partly restore the STZ-induced impairment of GLP-1 secretion, and inhibit the oxidative stress pathway, and thereby alleviate the progression of diabetes. This data demonstrated that the molecular mole ratio and molecular weight had a definite effect on antioxi- dant and anti-diabetic activities.

Soybean- and Lupin-Derived Peptides Inhibit DPP-IV Activity on In Situ Human Intestinal Caco-2 Cells and Ex Vivo Human Serum

Recent investigations have focused on food-derived peptides as novel natural inhibitors of dipeptidyl peptidase IV (DPP-IV), a new target for diabetes. This study aimed to optimize fast, sensitive, and cost-effective DPP-IV assays in situ on human intestinal Caco-2 cells and ex vivo on human serum. Both assays were applied to investigate the inhibitory activity of soy and lupin peptides. The best conditions for in situ DPP-IV activity in Caco-2 cells were obtained using 2-day cells and 50 µM Gly-Pro-AMC. Sitagliptin, used as reference inhibitor, showed a dose-dependent response with a 50% inhibition concentration (IC₅₀) of 0.6 µM. A lower IC₅₀ (0.2 µM) was obtained for sitagliptin on human serum incubated with the substrate for 24 h. Both assays were applied to assess the activity of Lup1 (LTFPGSAED) and Soy1 (IAVPTGVA) on DPP-IV. Lup1 and Soy1 inhibited DPP-IV in situ, with IC₅₀ values of of 207.5 and 223.2 µM, respectively, and maintained their inhibitory activity ex vivo on circulating DPP-IV with a slightly lower potency. These assays can be used to characterize the DPP-IV inhibitory activity of food-derived molecules more accurately than in vitro biochemical tests. This combined approach also considers their effects on the circulating form of DPP-IV, correlated to metabolic diseases.

Endophyte fungi, Cladosporium species-mediated synthesis of silver nanoparticles possessing in vitro antioxidant, anti-diabetic and anti-Alzheimer activity

This research study is to develop an easy and eco-friendly method for the synthesis of AgNPs using aqueous extract of endophytic fungi, Cladosporium species (CsAgNPs) and investigated the effects of antioxidant, anti-diabetic and anti-acetylcholinesterase (AChE), anti-butyrylcholinesterase (BChE) activity. Cladosporium species-mediated silver nanoparticles were characterized by UV-Vis spectrophotometer, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). The aqueous extract of Cladosporium species has shown the presence of carbohydrates, tannin, phenolic glycosides, terpenoids, alkaloids, phenol and anthraquinones. At 438 nm conformed the absorbance of AgNPs. The SEM result confirms that size, morphology and high density of the synthesized nanoparticles with huge disparity in the particle size distribution. The FTIR analysis confirmed the important biological compounds responsible for reduction of silver. Strong absorption property of AgNPs was studied by EDX. In antioxidant activity, CsAgNPs showed the involvement of NADPH-dependent reductase in the formation of AgNPs. The AgNPs has reduced the activity of α-amylase, α-glucosidase and dipeptidyl peptidase IV in vitro antidiabetic activity. The CsAgNPs showed significant glucose uptake in 3T3L1 cell line. The AgNPs have shown excellent inhibitory activity against AChE and BChE. To our best knowledge, this is the first on the synthesis of silver nanoparticles using endophytic fungi, Cladosporium species isolated from healthy leaf of Loranthus micranthus. Hence, to validate our results the in vivo animal studies at molecular level are needed to develop an antioxidant, anti-diabetic and anti-cholinesterase agent.

Regulatory Efficacy of Brown Seaweed Lessonia nigrescens Extract on the Gene Expression Profile and Intestinal Microflora in Type 2 Diabetic Mice

SCOPE

In this study, the antidiabetic activity of Lessonia nigrescens ethanolic extract (LNE) is investigated in streptozotocin (SZT)-induced type 2 diabetic mice fed with a high-sucrose/high-fat diet.

METHODS AND RESULTS

Ultra high performance liquid chromatography coupled with photo-DAD and electospray ionization-mass spectrometry (ESI-MS) is employed to analyze the major compounds in LNE. The components of the intestinal microflora in type 2 diabetic mice are analyzed by high-throughput next-generation 16S rRNA gene sequencing. Fasting blood glucose levels in diabetic mice are significantly decreased after LNE administration. The histology reveals that LNE could protect the cellular architecture of liver and kidney. LNE treatment significantly increases Bacteroidetes and decreases Firmicutes populations in intestinal microflora. Specifically, It could selectively enrich the amounts of beneficial bacteria, Barnesiella, as well as reduce the abundances of Clostridium and Alistipes. The increased gene and protein expression levels of phosphatidylinositol 3-kinase (PI3K) in the liver are observed in LNE treatment groups, while the expressions of c-Jun N-terminal kinase (JNK) are significantly downregulated.

CONCLUSION

The above findings suggest that LNE could be considered as a functional food for reducing blood glucose and regulating intestinal microflora.

Formulation of sitagliptin-loaded oral polymeric nano scaffold: process parameters evaluation and enhanced anti-diabetic performance

PURPOSE

The aim of the study to formulate and statistically optimize sitagliptin-loaded eudragit nanoparticles (SIT-NPs) and evaluate the in-vitro pharmaceutical quality and in-vivo anti-diabetic assessment.

METHOD

SIT-NPs were prepared by using combination method of solvent evaporation and nano-precipitation techniques. The influence of different independent variables as eudragit RL100 concentration (%), tween 80 concentration (%) and sonication time (min) were evaluated on dependent variables like particle size (nm), drug loading (%) and in-vitro drug release (%). Further, the optimized formulation was evaluated for surface morphology, CLSM, ex-vivo permeation study and in-vivo anti-diabetic activity and stability study.

RESULTS

The developed SIT-NPs formulations showed particle size range (135.86-193.45 nm), drug loading (6.36-8.76%) and prolonged drug release over 24 h. The prepared SIT-NPs were found to be nearly spherical with smooth surface. The comparative in-vitro release study and CLSM study results revealed that SIT-NPopt showed significantly (p < .05) enhanced release and permeation as compared to SIT free solution (SIT-Fs). The in-vivo anti-diabetic assessment revealed that SIT-NPopt able to reduce the blood sugar level (BSL) for a prolonged period of time. Further, the stability study data showed the formulations were found stable at both temperature and having the shelf life of 488 d.

CONCLUSIONS

This research has shown that SIT-NPs based on experimental design offers a new and better approach to delivering SIT, thus encouraging further development of this formulation.

Agrimoniin, an Active Ellagitannin from Comarum palustre Herb with Anti-α-Glucosidase and Antidiabetic Potential in Streptozotocin-Induced Diabetic Rats

Naturally existing α-glucosidase inhibitors from traditional herbal medicines have attracted considerable interest to treat type 2 diabetes mellitus (DM). The present study aimed to evaluate the anti-α-glucosidase activity of extracts from marsh cinquefoil (Comarum palustre L.), their hypoglycaemic action and detection of the responsible compounds. A 60% ethanol extract from C. palustre herb revealed the highest inhibitory activity against α-glucosidase (IC50 52.0 μg/mL). The HPLC analysis of the major compounds resulted in detection of 15 compounds, including ellagitannins, flavonoids, catechin and other compounds. Using HPLC activity-based profiling a good inhibitory activity of agrimoniin-containing eluates against α-glucosidase was demonstrated. The removal of ellagitannins from the C. palustre extract significantly decreased α-glucosidase inhibition (IC50 204.7 μg/mL) due to the high enzyme-inhibiting activity of the dominant agrimoniin (IC50 21.8 μg/mL). The hypoglycaemic effect of C. palustre extracts before and after ellagitannin removal, agrimoniin and insulin was evaluated on streptozotocin-induced experimental model. Diabetic rats treated with agrimoniin and C. palustre extract before ellagitannin removal showed significant increases in the levels of plasma glucose and glycosylated hemoglobin and significant decreases in the levels of plasma insulin and hemoglobin. The data obtained confirm the leading role of agrimoniin in the antidiabetic activity of the herb C. palustre and allows us to suggest the use of this plant as a possible dietary adjunct in the treatment of DM and a source of new oral hypoglycaemic agents.

Meadowsweet Teas as New Functional Beverages: Comparative Analysis of Nutrients, Phytochemicals and Biological Effects of Four Filipendula Species

In recent years, the increased popularity of functional beverages such as herbal teas and decoctions has led to the search for new sources of raw materials that provide appropriate taste and functionality to consumers. The objective of this study was to investigate the nutritional, phytochemical profiles and bioactivities of possible functional beverages produced from F. ulmaria and its alternative substitutes (F. camtschatica, F. denudata, F. stepposa). The investigated decoctions were analyzed regarding their macronutrient, carbohydrate, organic acid, amino acid and mineral composition. Quantification of the main phenolic compounds in the decoctions of meadowsweet floral teas was performed by a microcolumn RP-HPLC-UV procedure; the highest content was revealed in F. stepposa tea. The investigation of the essential oil of four meadowsweet teas revealed the presence of 28 compounds, including simple phenols, monoterpenes, sesquiterpenes and aliphatic components. The dominance of methyl salicylate and salicylaldehyde was noted in all samples. Studies on the water soluble polysaccharides of Filipendula flowers allowed us to establish their general affiliation to galactans and/or arabinogalactans with an admixture of glucans of the starch type and galacturonans as minor components. The bioactivity data demonstrated a good ability of meadowsweet teas to inhibit amylase, α-glucosidase and AGE formation. Tea samples showed antioxidant properties by the DPPH•, ABTS•+ and Br• free radicals scavenging assays and the carotene bleaching assay, caused by the presence of highly active ellagitannins. The anti-complement activity of the water-soluble polysaccharide fraction of meadowsweet teas indicated their possible immune-modulating properties. Filipendula beverage formulations can be expected to deliver beneficial effects due to their unique nutritional and phytochemical profiles. Potential applications as health-promoting functional products may be suggested.

Fractionation of Plant Bioactives from Black Carrots (Daucus carota subspecies sativus varietas atrorubens Alef.) by Adsorptive Membrane Chromatography and Analysis of Their Potential Anti-Diabetic Activity

Black and purple carrots have attracted interest as colored extracts for coloring food due to their high content of anthocyanins. This study aimed to investigate the polyphenol composition of black carrots. Particularly, the identification and quantification of phenolic compounds of the variety Deep Purple carrot (DPC), which presents a very dark color, was performed by HPLC-PDA and HPLC-ESI-MS(n) analyses. The separation of polyphenols from a DPC XAD-7 extract into an anthocyanin fraction (AF) and co-pigment fraction (CF; primarily phenolic acids) was carried out by membrane chromatography. Furthermore, possible anti-diabetic effects of the DPC XAD-7 extract and its AF and CF were determined. DPC samples (XAD-7, CF, and AF) inhibited α-amylase and α-glucosidase in a dose-dependent manner. Moreover, DPC XAD-7 and chlorogenic acid, but not DPC CF and DPC AF, caused a moderate inhibition of intestinal glucose uptake in Caco-2 cells. However, DPC samples did not affect glucagon-like peptide-1 (GLP-1) secretion and dipeptidyl peptidase IV (DPP-4) activity. Overall, DPC exhibits an inhibitory effect on α-amylase and α-glucosidase activity and on cellular glucose uptake indicating potential anti-diabetic properties.

Synthesis and Biological Activity of Isoflavone Derivatives from Chickpea as Potent Anti-Diabetic Agents

A set of novel isoflavone derivatives from chickpea were synthesized. The structures of derivatives were identified by proton nuclear magnetic resonance (¹H-NMR), carbon-13 (¹³C)-NMR and mass spectrometry (MS) spectral analyses. Their anti-diabetic activities were evaluated using an insulin-resistant (IR) HepG2 cell model. Additionally, the structure-activity relationships of these derivatives were briefly discussed. Compounds 1c, 2h, 3b, and 5 and genistein exhibited significant glucose consumption-enhancing effects in IR-HepG2 cells. In addition, the combinations of genistein, 2h, and 3b (combination 6) and of 3b, genistein, and 1c (combination 10) exhibited better anti-diabetic activity than the individual compounds. At the same dosage, there was no difference in effect between the combination 10 and the positive control (p > 0.05). Aditionally, we found the differences between the combination 10 and combination 6 for the protective effect of HUVEC (human umbilical vein endothelial cells) under high glucose concentration. The protective effects of combination 10 was stronger than combination 6, which suggested that combination 10 may have a better hypoglycemic activity in future studies. This study provides useful clues for the further design and discovery of anti-diabetic agents.

Evaluation of Antioxidant, Antidiabetic and Anticholinesterase Activities of Smallanthus sonchifolius Landraces and Correlation with Their Phytochemical Profiles

The present study aimed to investigate the phytochemical profile of leaf methanol extracts of fourteen Smallanthus sonchifolius (yacon) landraces and their antioxidant, anticholinesterase and antidiabetic activities that could lead to the finding of more effective agents for the treatment and management of Alzheimer's disease and diabetes. For this purpose, antioxidant activity was assessed using different tests: ferric reducing ability power (FRAP), 2,2-diphenyl-1-picryl hydrazyl (DPPH), nitric oxide (˙NO) and superoxide (O2˙-) scavenging and lipid peroxidation inhibition assays. Anticholinesterase activity was investigated by quantifying the acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities, whereas antidiabetic activity was investigated by α-amylase and α-glucosidase inhibition tests. To understand the contribution of metabolites, phytochemical screening was also performed by high performance liquid chromatography-diode array detector (HPLC-DAD) system. Among all, methanol extract of PER09, PER04 and ECU44 landraces exhibited the highest relative antioxidant capacity index (RACI). ECU44 was found to be rich in 4,5-di-O-caffeoylquinic acid (CQA) and 3,5-di-O-CQA and displayed a good α-amylase and α-glucosidase inhibition, showing the lowest IC50 values. Flavonoids, instead, seem to be involved in the AChE and BChE inhibition. The results of this study revealed that the bioactive compound content differences could be determinant for the medicinal properties of this plant especially for antioxidant and antidiabetic activities.

Effect of superfine grinding on antidiabetic activity of bitter melon powder

The antidiabetic activities of bitter melon powders produced with lyophilization/superfine grinding and hot air drying/normal grinding were investigated in vivo for selecting a suitable bitter melon processing procedure. After a five-week treatment, bitter melon lyophilized superfine grinding powder (BLSP) had a higher antidiabetic activity with reducing fasting blood glucose levels from 21.40 to 12.54 mmol/L, the serum insulin levels from 40.93 to 30.74 mIU/L, and restoring activities of SOD compared with those in the bitter melon hot air drying powder (BAP) treated group. Furthermore, BLSP protected pancreatic tissues including islet beta cells and reduced the loss of islet cells. Combined with the difference of compositions in BLSP and BAP, it could be concluded that superfine grinding and lyophilization processes were beneficial for presenting the antidiabetic activity, which will provide a reference for direct utilization of bitter melon as a suitable functional food to relieve symptoms of diabetes.