Preparation of a Momordica charantia L. polysaccharide‑chromium (III) complex and its anti-hyperglycemic activity in mice with streptozotocin-induced diabetes

Antihyperglycemic, Antiaging, and L. brevis Growth-Promoting Activities of an Exopolysaccharide from Agrobacterium sp. FN01 (Galacan) Evaluated in a Zebrafish (Danio rerio) Model

Agrobacterium sp. are notable for their ability to produce substantial amounts of exopolysaccharides. Our study identified an exopolysaccharide (Galacan, 4982.327 kDa) from Agrobacterium sp. FN01. Galacan is a heteropolysaccharide primarily composed of glucose and galactose at a molar ratio of 25:1. The FT-IR results suggested that Galacan had typical absorption peaks of polysaccharide. The results of periodate oxidation, Smith degradation, and NMR confirmed the presence of structural units, such as β-D-Galp(→, →3)β-D-Galp(1→, →2,3)β-D-Glcp(1→, β-D-Glcp(1→, and →2)β-D-Glcp(1→. Galacan demonstrated significant biological activities. In experiments conducted with zebrafish, it facilitated the proliferation of Lactobacillus brevis in the intestinal tract, suggesting potential prebiotic properties. Moreover, in vivo studies revealed its antihyperglycemic effects, as evidenced by significant reductions in blood glucose levels and enhanced fluorescence intensity of pancreatic β cells in a streptozotocin (STZ)-induced hyperglycemic zebrafish model. Additionally, antiaging assays demonstrated Galacan's ability to inhibit β-galactosidase activity and enhance telomerase activity in a hydrogen peroxide (HP)-induced aging zebrafish model. These findings emphasized the potential of Galacan as a natural prebiotic with promising applications in diabetes prevention and antiaging interventions.

Preparation of a hydrolyzed yeast β-glucan chromium(III) complex and evaluation of its hypoglycemic activity and sub-acute toxicity

Yeast β-glucan (BYG) possesses extremely low solubility that has limited its applications. In this study, we hydrolyzed BYG using snail enzyme to obtain hydrolyzed yeast β-glucan (HBYG) with desirable water solubility and hypoglycemic activity. On the basis of HBYG, HBYG‑chromium(III) complex (HBYG-Cr) was synthesized. The molecular weight of the complex was 4.41 × 104 Da, and the content of trivalent chromium was 8.95 %. The hydroxyl groups of HBYG participated in the coordination and formed the chromium complex. The space conformations of HBYG exhibited remarkable changes after complex formation. HBYG-Cr existed mainly in an amorphous state and presented good dispersibility, and the surface was uneven. The hypoglycemic activity of HBYG-Cr was studied in db/db and C57 mice. The results showed that HBYG-Cr had good hypoglycemic activity. Histopathological studies demonstrated that the liver, kidney, pancreas, and skeletal muscle in the treatment group were significantly improved compared with those in the diabetic model group. The sub-acute toxicity of HBYG-Cr was studied in KM mice and the results indicated that the complex did not cause adverse reactions or toxic side effects. This study broadened the application of yeast β-glucan and provided an important reference for the development of hypoglycemic functional foods and drugs.

Is chromium(III) pharmacologically relevant? An update focused on studies with diabetic rodent models

A decade ago, the author assessed the status of chromium as the trivalent ion as an essential element and as a therapeutic agent based on rodent studies for this journal. The current review was undertaken to update considerations regarding the status of chromium, focusing on studies of Cr supplementation of diabetic rodent models over the last decade. Cr can no longer be considered an essential trace element for humans. Observed effects of Cr on rodent models of insulin resistance and diabetes are best interpreted in terms of a pharmacological role for Cr. The review of studies on the effects of Cr on rat models of diabetes is updated, and the results continue to suggest Cr increases insulin sensitivity in peripheral tissues of the rodent models. The lack of effects in human studies may stem from humans receiving a comparably smaller dose than the rodent models. However, given the different responses to Cr in the rodent models, humans could potentially have different responses to Cr. Recent studies primary utilizing rodents suggest two potential complementary but also contradictory modes of action for Cr(III) at a molecular level.

Extraction, structures, biological effects and potential mechanisms of Momordica charantia polysaccharides: A review

Momordica charantia L. is a kind of vegetable with medicinal value. As the main component of the vegetable, Momordica charantia polysaccharides (MCPs) mainly consist of galactose, galacturonic acid, xylose, rhamnose, mannose and the molecular weight range is 4.33 × 103-1.16 × 106 Da. MCPs have been found to have various biological activities in recent years, such as anti-oxidation, anti-diabetes, anti-brain injury, anti-obesity, immunomodulatory and anti-inflammation. In this review, we systematically summarized the extraction methods, structural characteristics and physicochemical properties of MCPs. Especially MCPs modulate gut microbiota and cause the alterations of metabolic products, which can regulate different signaling pathways and target gene expressions to exert various functions. Meanwhile, the potential structure-activity relationships of MCPs were analyzed to provide a scientific basis for better development or modification of MCPs. Future researches on MCPs should focus on industrial extraction and molecular mechanisms. In East Asia, Momordica charantia L. is used as both food and medicine. It is not clear whether MCP has its unique biological effects. Further study on the difference between MCPs and other food-derived polysaccharides will be helpful to the development and potential application of Momordica charantia L.

Preparation of a Novel Oat β-Glucan-Chromium(III) Complex and Its Hypoglycemic Effect and Mechanism

This study synthesized a novel oat β-glucan (OBG)-Cr(III) complex (OBG-Cr(III)) and explored its structure, inhibitory effects on α-amylase and α-glucosidase, and hypoglycemic activities and mechanism in vitro using an insulin-resistant HepG2 (IR-HepG2) cell model. The Cr(III) content in the complex was found to be 10.87%. The molecular weight of OBG-Cr(III) was determined to be 7.736 × 104 Da with chromium ions binding to the hydroxyl groups of OBG. This binding resulted in the increased asymmetry and altered spatial conformation of the complex along with significant changes in morphology and crystallinity. Our findings demonstrated that OBG-Cr(III) exhibited inhibitory effects on α-amylase and α-glucosidase. Furthermore, OBG-Cr(III) enhanced the insulin sensitivity of IR-HepG2 cells, promoting glucose uptake and metabolism more efficiently than OBG alone. The underlying mechanism of its hypoglycemic effect involved the modulation of the c-Cbl/PI3K/AKT/GLUT4 signaling pathway, as revealed by Western blot analysis. This research not only broadened the applications of OBG but also positioned OBG-Cr(III) as a promising Cr(III) supplement with enhanced hypoglycemic benefits.

Extraction methods, multiple biological activities, and related mechanisms of Momordica charantia polysaccharide: A review

Momordica Charantia Polysaccharide (MCP) is a key bioactive compound derived from bitter melon fruit. This review summarizes the advancements in MCP research, including extraction techniques, biological activities, and mechanisms. MCP can be extracted using various methods, and has demonstrated hypoglycemic, antioxidant, anti-inflammatory, and immunoregulatory effects. Research suggests that MCP may regulate metabolic enzymes, oxidative stress reactions, and inflammatory pathways. The review highlights the potential applications of MCP in areas such as anti-diabetes, antioxidant, anti-inflammatory, and immunoregulatory research. Future research should focus on elucidating the molecular mechanisms of MCP and optimizing extraction methods. This review provides a foundation for further research and utilization of MCP.

Bioactive polysaccharides from Momordica charantia as functional ingredients: a review of their extraction, bioactivities, structural-activity relationships, and application prospects

Momordica charantia L. is a well-known medicine and food homology plant with high pharmaceutical and nutritional values. Polysaccharides are carbohydrate polymers connected by glycosidic bonds, one of the key functional ingredients of M. charantia. Recently, M. charantia polysaccharides (MCPs) have attracted much attention from industries and researchers due to their anti-oxidant, anti-tumor, anti-diabetes, anti-bacteria, immunomodulatory, neuroprotection, and organ protection activities. However, the development and utilization of MCPs-based functional foods and medicines were hindered by the lack of a deeper understanding of the structure-activity relationship (SAR), structural modification, applications, and safety of MCPs. Herein, we provide an overview of the extraction, purification, structural characterization, bioactivities, and mechanisms of MCPs. Besides, SAR, toxicities, application, and influences of the modification associated with bioactivities are spotlighted, and the potential development and future study direction are scrutinized. This review provides knowledge and research underpinnings for the further research and application of MCPs as therapeutic agents and functional food additives.

Cordyceps cicadae polysaccharides alleviate hyperglycemia by regulating gut microbiota and its mmetabolites in high-fat diet/streptozocin-induced diabetic mice

Introduction

The polysaccharides found in Cordyceps cicadae (C. cicadae) have received increasing academic attention owing to their wide variety of therapeutic activities.

Methods

This study evaluated the hypoglycemic, antioxidant, and anti-inflammatory effects of polysaccharides from C. cicadae (CH-P). In addition, 16s rDNA sequencing and untargeted metabolomics analysis by liquid chromatography-mass spectrometry (LC-MS) were used to estimate the changes and regulatory relationships between gut microbiota and its metabolites. The fecal microbiota transplantation (FMT) was used to verify the therapeutic effects of microbial remodeling.

Results

The results showed that CH-P treatment displayed hypoglycemic, antioxidant, and anti-inflammatory effects and alleviated tissue damage induced by diabetes. The CH-P treatment significantly reduced the Firmicutes/Bacteroidetes ratio and increased the abundance of Bacteroides, Odoribacter, Alloprevotella, Parabacteroides, Mucispirillum, and significantly decreased the abundance of Helicobacter and Lactobacillus compared to the diabetic group. The alterations in the metabolic pathways were mostly related to amino acid biosynthesis and metabolic pathways (particularly those involving tryptophan) according to the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Correlation analysis showed that Bacteroides, Odoribacter, Alloprevotella, Parabacteroides, and Mucispirillum were positively correlated with indole and its derivatives, such as 5-hydroxyindole-3-acetic acid. Indole intervention significantly improved hyperglycemic symptoms and insulin sensitivity, and increased the secretion of glucagon-like peptide-1 (GLP-1) in diabetic mice. FMT reduced blood glucose levels, improved glucose tolerance, and increased insulin sensitivity in diabetic mice. However, FMT did not significantly improve GLP-1 levels.

Discussion

This indicates that C. cicadae polysaccharides alleviate hyperglycemia by regulating the production of metabolites other than indole and its derivatives by gut microbiota. This study provides an important reference for the development of novel natural products.

Polysaccharides from natural resource: ameliorate type 2 diabetes mellitus via regulation of oxidative stress network

Diabetes mellitus (DM) is a group of metabolic diseases characterized by hyperglycemia that can occur in children, adults, elderly people, and pregnant women. Oxidative stress is a significant adverse factor in the pathogenesis of DM, especially type 2 diabetes mellitus (T2DM), and metabolic syndrome. Natural polysaccharides are macromolecular compounds widely distributed in nature. Some polysaccharides derived from edible plants and microorganisms were reported as early as 10 years ago. However, the structural characterization of polysaccharides and their therapeutic mechanisms in diabetes are relatively shallow, limiting the application of polysaccharides. With further research, more natural polysaccharides have been reported to have antioxidant activity and therapeutic effects in diabetes, including plant polysaccharides, microbial polysaccharides, and polysaccharides from marine organisms and animals. Therefore, this paper summarizes the natural polysaccharides that have therapeutic potential for diabetes in the past 5 years, elucidating their pharmacological mechanisms and identified primary structures. It is expected to provide some reference for the application of polysaccharides, and provide a valuable resource for the development of new diabetic drugs.

Characterization of manganized soluble dietary fiber complexes from tigernut meal and study of the suppressive activity of digestive enzymes in vitro

In this study, manganized soluble dietary fiber (SDF-Mn(II)) was prepared from tigernut meal using a microwave solid-phase synthesis method with SDF. Microscopic morphological and structural analyses of SDF-Mn(II) were carried out using scanning electron microscopy, Fourier infrared spectroscopy, UV full-band scanning, X-ray diffraction, a thermal analyzer, gel permeation chromatography, and nuclear magnetic resonance, and its in vitro hypoglycemic activity was initially investigated. The results of these analyses revealed that the reaction of Mn(II) with SDF mainly involved hydroxyl and carbonyl groups, with the Nuclear magnetic resonance (NMR) analysis showing that specific covalent binding was produced and substitution was mainly carried out at the C₆ position. Moreover, compared with SDF, the SDF-Mn(II) complex exhibited a porous structure, red-shifted, and color-enhancing effects on the UV characteristic peaks, significantly increased crystallinity and decreased molecular weight, and improved thermal stability; in addition, SDF-Mn(II) afforded significantly enhanced inhibition of α-amylase and α-glucosidase and possesses good in vitro digestive enzyme inhibition activity.

Garlic polysaccharide-Cr (III) complexes with enhanced in vitro and in vivo hypoglycemic activities

This study aimed to prepare a complex of Cr (III) and garlic polysaccharides (GPs) and evaluate the in vitro and in vivo hypoglycemic activities of GPs and GP-Cr (III) complexes. The chelation of GPs with Cr (III) increased molecular weight, modified crystallinity, and altered morphological characteristics, through targeting the OH of hydroxyl groups and involving the C-O/O-C-O structure. The GP-Cr (III) complex had a higher thermal stability over 170-260 °C and higher stability throughout the gastrointestinal digestion. In vitro, the GP-Cr (III) complex exhibited a significantly stronger inhibitory effect against α-glucosidase compared with the GP. In vivo, the GP-Cr (III) complex at a high dose (4.0 mg Cr/kg body weight) generally had a higher hypoglycemic activity than the GP in (pre)-diabetic mice induced by a high-fat and high-fructose diet, based on indices like body weight, blood glucose levels, glucose tolerance, insulin resistance, insulin sensitivity, blood lipid levels, and hepatic morphology and function. Therefore, GP-Cr (III) complexes could be a potential Cr (III) supplement with an enhanced hypoglycemic activity.

Evaluation of Hypoglycemic Activity and Sub-Acute Toxicity of the Novel Biochanin A–Chromium(III) Complex

The novel biochanin A–chromium(III) complex was synthesized by chelating chromium with biochanin A (BCA). The structure of the complex was determined and the complex ([CrBCA3]) was composed of chromium(III) and three ligands, and the chromium content was 55 μg/mg. The hypoglycemic activity of the complex was studied in db/db mice and C57 mice. The sub-acute toxicity test of the complex was carried out by the maximum limit method in KM mice. The hypoglycemic activity showed that the complex could reduce the weight of db/db mice and lower the fasting blood glucose and random blood glucose levels. The complex also improved the organ index, oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) results of db/db mice, and some of the indicators were similar to those of the positive control group after treatment with the complex. The histopathology study showed significant improvements in the liver, kidney, pancreas and skeletal muscle compared with the diabetes model group. The complex also showed a significant improvement in serum biochemical indices and antioxidant enzyme activities, as well as glycogen levels. The sub-acute toxicity study showed that the complex did not cause death or any dangerous symptoms during the study. In addition, the sub-acute toxicity study showed that the complex had no significant effect on the serum biochemical indices, antioxidant capacity and organs of normal mice. This study showed that [CrBCA3] had good hypoglycemic activity in vivo and had no sub-acute toxicity. This work provides an important reference for the development of functional hypoglycemic foods or drugs.

Pumpkin Skin Polysaccharide–Zn(II) Complex: Preparation, Characterization, and Suppression of Inflammation in Zebrafish

In this study, pumpkin (Cucurbita moschata) skin polysaccharide–zinc(II) (PSP−Zn) complex was successfully prepared. The structure and physicochemical properties of PSP and PSP−Zn were analyzed. The anti-inflammatory activity of PSP and PSP−Zn was investigated in zebrafish larvae induced by copper sulphate. PSP and PSP−Zn consisted of rhamnose, arabinose, galactose, glucose, and galacturonic acid. The molecular weight (Mw) of PSP and PSP−Zn were 3.034 × 10⁶ and 3.222 × 10⁶ Da, respectively. Fourier transform infrared spectrum (FT-IR) and circular dichroism (CD) analysis results suggested that the chemical modification of zinc might occur through hydroxyl groups of PSP. The PSP−Zn complex had lamellar texture, smooth surface morphology, and larger particle size. X-ray Diffraction (XRD) analysis revealed that both PSP and PSP−Zn were semi-crystalline substances. PSP−Zn solution showed superior stability in a weak acid and alkaline environment, especially at pH = 6.0. Moreover, PSP and PSP−Zn showed a good inhibitory effect on inflammation cells in zebrafish. Real-time quantitative polymerase chain reaction (RT-PCR) result suggested that the anti-inflammatory mechanism of PSP and PSP−Zn were through downregulation of the expression of nitric oxide synthase 2b (nos2b), inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), and nuclear factor-kappa B2 (NF-κB2). The present study indicated that PSP−Zn is expected to be a safe and efficient novel zinc supplement with anti-inflammatory activity.

Structural Characterization and Hypoglycemic Activity of a Novel Pumpkin Peel Polysaccharide-Chromium(III) Complex

The aim of our study was to synthesize a pumpkin peel polysaccharide (PPP)-Cr(III) complex and investigate its hypoglycemic activity. Firstly, a novel PPP-Cr(III) complex with a Cr content of 23.77 mg/g was synthesized and characterized. Physicochemical characterization indicated that PPP-Cr(III) had some changes in chemical composition, monosaccharide composition, and morphological structure compared with PPP. The molecular weights of PPP-Cr(III) and PPP were 1.398 × 106 g/mol and 3.386 × 106 g/mol, respectively, showing a lower molecular weight after the introduction of Cr(III). Fourier transform infrared spectroscopy showed that a new characteristic absorption peak of Cr-O appeared at 534 cm-1 in PPP-Cr(III), indicating that Cr(III) was successfully complexed with PPP. Secondly, the hypoglycemic activity of PPP-Cr(III) based on α-glucosidase inhibitory and insulin resistance (IR)-HepG2 cells was evaluated. Compared with PPP, PPP-Cr(III) exhibited a more significantly α-glucosidase inhibitory activity. The IR-HepG2 cells confirmed an obvious increase in glucose consumption. Western blot analysis demonstrated that the treated IR-HepG2 cells were able to increase the protein levels of p-AMPK and p-GSK-3β, indicating that IR-HepG2 cells exerted hypoglycemic activity via the AMPK/GSK-3β signaling pathway. These results suggested that PPP-Cr(III) had good hypoglycemic activity, which could provide theoretical support for the development of novel hypoglycemic products.

Synthesis, Characterization, and Bioactivities of Polysaccharide Metal Complexes: A Review

Natural polysaccharides are critical to a wide range of fields (e.g., medicine, food production, and cosmetics) for their various remarkable physical properties and biological activities. However, the bioactivities of naturally acquired polysaccharides may be unsatisfactory and limit their further applications. It is generally known that the chemical structure exhibited by polysaccharides lays the material basis for their biological activities. Accordingly, possible structural modifications should be conducted on polysaccharides for their enhancement. Recently, polysaccharides complexed with metal ions (e.g., Fe, Zn, Mg, Cr, and Pt) have been reported to be possibly used to improve their bioactivities. Moreover, since the properties exhibited by metal ions are normally conserved, polysaccharides may be endowed with new applications. In this review, the synthesis methods, characterization methods, and bioactivities of polysaccharide metal complexes are summarized specifically. Then, the application prospects and limitations of these complexes are analyzed and discussed.

Hypolipidemic effect of chromium-modified enzymatic product of sulfated rhamnose polysaccharide from Enteromorpha prolifera in type 2 diabetic mice

Sulfated rhamnose polysaccharide (SRP) derived from Enteromorpha prolifera is a metal-ion chelating agent that could potentially be used to treat diabetes. The aim of our study was to determine the effect of a variant of SRP on DIABETES. First, we synthesized and characterized SRPE-3 chromium(III) [SRPE-3-Cr(III)] complex using an enzymatic method. The maximum chelation rate was 18.2% under optimal chelating conditions of pH 6.0, time 4 h, and temperature 60 °C. Fourier transform infrared spectroscopy results showed important sites for Cr(III)-binding were O-H and C=O groups. We then studied the hypolipidemic effects of SRPE-3-Cr(III) on type 2 diabetes mellitus (T2DM) induced by a high-fat, high-sucrose diet (HFSD). Decreased blood glucose content, body fat ratio, serum TG, TC, LDL-C, and increased serum HDL-C were observed after treatment with SRPE-3-Cr(III). In addition, SRPE-3-Cr(III) significantly reduced leptin, resistin, and TNF-α levels, and increased adiponectin contents relative to T2DM. Histopathology results also showed that SRPE-3-Cr(III) could alleviate the HFSD-lesioned tissues. SRPE-3-Cr(III) also improved lipid metabolism via a reduction in aspartate aminotransferase, alanine aminotransferase, fatty acid synthase, and acetyl-CoA carboxylase activities in the liver. SRPE-3-Cr(III) at low doses exhibited better lipid-lowering activities, hence, could be considered to be a novel compound to treat hyperlipidemia and also act as an anti-diabetic agent.

Structural characterization of a novel polysaccharide from sweet corncob that inhibits glycosylase in STZ-induced diabetic rats : Structural characterization of a novel polysaccharide

In the current study, we extracted a polysaccharide from sweet corncob and evaluated its hypoglycemic function. After collection in water, alcohol precipitation, and purification by DEAE-52 and Sephadex G-100 columns, we obtained a polysaccharide (SCP50) that was composed primarily of mannose and glucose (9.73:190.27), with a molecular weight of 9280.33 Da. We demonstrated that SCP50 exhibited significant inhibition of α-glucosidase activity, with an IC50 of 4.866 mg/mL, K_m of 1.297 × 10^-3, and V_max of 0.076 mol/L·min^-1 in vitro. We also observed that SCP50 markedly attenuated disaccharidase (maltase, sucrase, and lactase) activity in a rat model of T2DM. We conclude that SCP50 exerts a hypoglycemic effect via inhibition of intestinal glycosylase. These results thus provide new insight into the hypoglycemic action underlying sweet corncob polysaccharide's effects.

6,8-(1,3-Diaminoguanidine) luteolin and its Cr complex show hypoglycemic activities and alter intestinal microbiota composition in type 2 diabetes mice

Flavonoid compounds such as luteolin exhibit hypolipidemic effects, and there are few reports on the hypoglycemic activity of luteolin derivatives. In this research, 6,8-(1,3-diaminoguanidine) luteolin (DAGL) and its Cr complex (DAGL·Cr) were obtained as a result of structural modifications to luteolin, and the hypoglycemic activities and the composition of intestinal microbiota in T2DM mice were investigated. This study found that DAGL and DAGL·Cr could significantly restore body weight, FBG, OGTT, AUC, and GSP in T2DM mice. Moreover, the pancreatic islet function index and the biochemical indicators of serum and the liver were also significantly improved. The histopathological results also showed that DAGL and DAGL·Cr had a stronger repair ability in the liver and the pancreas. It was also revealed that the potential hypoglycemic mechanism of DAGL and DAGL·Cr was involved in the simultaneous regulation of PI3K/AKT-1/GSK-3β/GLUT-4 and PI3K/AKT-1/mTOR/S6K1/IRS-1. Furthermore, DAGL and DAGL·Cr could also regulate the structure of the intestinal microbiota and increase the content of SCFA to relieve the symptoms of hyperglycemia in T2DM mice. This included a significant reduction in the ratio of Firmicutes and Bacteroidetes (F/B), and at the genus level, an increase in the relative abundance of Alistipe and Ruminiclostridium, and improvement in the content of SCFA in the feces of T2DM mice. In conclusion, in this study, DAGL and DAGL·Cr were found to improve hyperglycemia in T2DM mice by improving the pancreatic islet function index, regulating the biochemical indicators of serum and the liver, repairing damaged tissues, and regulating the PI3K/AKT-1 signaling pathway as well as reducing F/B, increasing the relative abundance of intestinal beneficial microbiota, and the content of SCFA in the feces. The hypoglycemic effect of DAGL·Cr on the body weight, serum IL-10, serum IL-6, and pancreatic islet function index was significantly better than that of DAGL.

Immunomodulatory effects and associated mechanisms of Momordica charantia and its phytochemicals

Momordica charantia L. (M. charantia), which is a member of the Cucurbitaceae family and widely distributed in tropical and subtropical regions, has been consumed as a vegetable and also used as herbal medicine for thousands of years worldwide.

The novel anti-inflammatory activity of mcIRBP from Momordica charantia is associated with the improvement of diabetic nephropathy

Diabetic nephropathy is an inflammatory immune disorder accompanying diabetes.

Antidiabetic Medicinal Plants Used in Democratic Republic of Congo: A Critical Review of Ethnopharmacology and Bioactivity Data

Several studies have been conducted and published on medicinal plants used to manage Diabetes Mellitus worldwide. It is of great interest to review available studies from a country or a region to resort to similarities/discrepancies and data quality. Here, we examined data related to ethnopharmacology and bioactivity of antidiabetic plants used in the Democratic Republic of Congo. Data were extracted from Google Scholar, Medline/PubMed, Scopus, ScienceDirect, the Wiley Online Library, Web of Science, and other documents focusing on ethnopharmacology, pharmacology, and phytochemistry antidiabetic plants used in the Democratic Republic of Congo from 2005 to September 2021. The Kew Botanic Royal Garden and Plants of the World Online web databases were consulted to verify the taxonomic information. CAMARADES checklist was used to assess the quality of animal studies and Jadad scores for clinical trials. In total, 213 plant species belonging to 72 botanical families were reported. Only one plant, Droogmansia munamensis, is typically native to the DRC flora; 117 species are growing in the DRC and neighboring countries; 31 species are either introduced from other regions, and 64 are not specified. Alongside the treatment of Diabetes, about 78.13% of plants have multiple therapeutic uses, depending on the study sites. Experimental studies explored the antidiabetic activity of 133 plants, mainly in mice, rats, guinea pigs, and rabbits. Several chemical classes of antidiabetic compounds isolated from 67 plant species have been documented. Rare phase II clinical trials have been conducted. Critical issues included poor quality methodological protocols, author name incorrectly written (16.16%) or absent (14.25%) or confused with a synonym (4.69%), family name revised (17.26%) or missing (1.10%), voucher number not available 336(92.05%), ecological information not reported (49.59%). Most plant species have been identified and authenticated (89.32%). Hundreds of plants are used to treat Diabetes by traditional healers in DRC. However, most plants are not exclusively native to the local flora and have multiple therapeutic uses. The analysis showed the scarcity or absence of high-quality, in-depth pharmacological studies. There is a need to conduct further studies of locally specific species to fill the gap before their introduction into the national pharmacopeia.

Antidiabetic potential of the isolated fractions from the plants of Rosaceae family in streptozotocin-induced diabetic rats

Background and purpose:

Diabetes is a group of multifactorial disorders characterized by chronic-elevated blood glucose levels (hyperglycemia). Natural remedies are used as alternative medications to treat diabetes. Here, we tested the protective effect of the plant extracts of the Rosaceae family on improving insulin secretion and repairing the pancreatic beta cells in diabetic rats.

Experimental approach:

The oligosaccharide fraction was isolated from the Rosaceae family of herbs. LC-MS/MS was applied to characterize the isolated fractions. The male Wistar rats were randomly divided into six groups, 10 each, including the control group with no intervention, diabetic rats without treatment, diabetic rats that received the extract of Malus domestica (apple), Cydonia oblonga (quince), Prunus persica (nectarine), and Prunus persica (peach), separately. Rats were monitored for the weight, fasting plasma glucose, and insulin levels. The effect of extracts in streptozotocin (STZ)-induced diabetic rats on the pancreatic islets was evaluated by morphometric analysis.

Findings/Results:

LC-MS/MS results indicated a similar mass spectrum of isolated fractions from nectarine and peach with Rosa canina. Oral administration of nectarine and peach extracts to STZ-induced diabetic rats showed restoration of blood glucose levels to normal levels with a concomitant increase in insulin levels. Morphometric analysis of pancreatic sections revealed the increase in number, diameter, volume, and area of the pancreatic islets in the diabetic rats treated with extracts compared to the untreated diabetic rats.

Conclusion and implications:

Nectarine and peach extracts’ anti-diabetic properties improved insulin secretion and pancreatic beta-cell function and subsequently led to restoring pancreatic islet mass in STZ-induced diabetic rats.

Macromolecular and thermokinetic properties of a galactomannan from Sophora alopecuroides L. seeds: A study of molecular aggregation

The molecular aggregation of a galactomannan (NSAP-25) from Sophora alopecuroides L. seeds was investigated, where three polydisperse systems were confirmed during particle size analysis, indicating existence of different aggregates composed of random coil chains revealed by circular dichroism. Morphologically, NSAP-25 aggregate of various sizes (200-1200 nm) was possibly multi-stranded and formed by ellipsoid-like particles (20-60 nm) composed of compact coil chain, exhibiting extended amorphous structure with chain-like branches intertwined. Hence, NSAP-25 aggregation was inevitable, which exerted an unignorable effect on augmenting flexibility (β↓, γ↓, α↓ and L_p/M_L↓) and compactness (ρ↓, d_f↑ and C_∞↓) of branched random coil chain based on macromolecular analysis, especially when concentration increased. Moreover, it could be relevant to thermokinetic behavior of random nucleation and subsequent growth (A² model and negative ΔS*) as well as good thermal stability (IPDT, ITS, t_0.05, T_m and T_p), thus conferring potential applications for NSAP-25 in food and pharmaceutical industries.

The Effect of Momordica charantia in the Treatment of Diabetes Mellitus: A Review

In recent years, many studies of Momordica charantia (MC) in the treatment of diabetes mellitus (DM) and its complications have been reported. This article reviewed the effect and mechanism of MC against diabetes, including the results from in vitro and in vivo experiments and clinical trials. The common side effects of MC were also summarized. We hope that it might open up new ideas for further mechanism exploration and clinical application as well as provide a scientific theoretical basis for the development of drugs or foods derived from MC.

Protective effect of the isolated oligosaccharide from Rosa canina in STZ-treated cells through modulation of the autophagy pathway

Isolation of active components of therapeutic plants and discovering molecular mechanisms play a pivotal role in therapy of diabetes. This study aimed to determine the antidiabetic mechanism of an oligosaccharide isolated from Rosa canina (RCO) by measuring the expression of some miRNAs and their targets involved in autophagy. RCO was extracted and characterized by using HPLC and spectroscopic methods. Rin-5F cells were treated with STZ and RCO alone and in combination. The viability of the cells and the expression of miR-21, miR-22, Akt, ATG5, Beclin1, LC3A, and LC3B were analyzed using MTT assay, and qRT-PCR, respectively. Oligosaccharide fraction could improve the viability of RCO-treated cells as compared to STZ-treated cells. Further, the expression of autophagy markers was increased in RCO-treated diabetic cells compared to STZ-treated cells. The results indicated that the antidiabetic effects of the oligosaccharide components of R. canina seem to be mediated by modulation of autophagy pathway. PRACTICAL APPLICATIONS: Given effectiveness of an oligosaccharide fraction isolated from Rosa canina in management of diabetes in STZ-induced diabetic rats, we have intention to scrutinize its molecular mechanism as modulation of autophagy pathway in STZ-treated Rin-5F cells. It is expected that the results paved the way to speculate novel antidiabetic strategies.

Cucurbitane-Type Triterpene Glycosides from Momordica charantia and Their α-Glucosidase Inhibitory Activities

Ten cucurbitane-type triterpene glycosides, including five new compounds named charantosides H (1), J (2), K (3), momorcharacoside A (4), goyaglycoside-L (5), and five known compounds (6-10), were isolated from the EtOAc extract of Momordica charantia fruits. The chemical structures of these compounds were identified by 1D and 2D NMR and HRESIMS spectroscopic analyses. Configurations of new compounds were determined by ROESY correlations and comparison of their ¹³C NMR data with literature reported values. All compounds were evaluated for their inhibition against α-glucosidase, in which compounds 2, 5, 7, 8, 9 showed moderate inhibitory activities with IC₅₀ values ranging from 28.40 to 63.26 μM comparing with the positive control (acarbose, IC₅₀ 87.65 ± 6.51 μM).

Preparation and Characterization of a Novel Polysaccharide-Iron(III) Complex in Auricularia auricula Potentially Used as an Iron Supplement

Iron deficiency anemia has been a widespread disease. As an effective and stable iron supplement, the physiochemical properties of the polysaccharide iron complex have been widely studied. In this study, we characterized a novel polysaccharide-iron(III) complex extracted in an edible fungal species Auricularia auricular (AAPS-iron(III)). The highest iron content (28.40%) in the AAPS-iron(III) complex was obtained under the optimized preparation conditions including an AAPS to FeCl3∙ 6H2O ratio of 2:3 (w/w), a pH value of 8.0 in solution, a reaction temperature of 50°C, and a reaction time of 3 h. The physical and chemical properties of the AAPS-iron(III) complex were characterized by qualitative and quantitative analyses using scanning electron microscope, particle size distribution, thermogravimetric analyzer, Fourier transform infrared spectroscopy, circular dichroism, and 1H nuclear magnetic resonance. Result showed that, although the iron was bound to the polysaccharide, it was released under artificial gastrointestinal conditions. The AAPS-iron(III) complex exhibited high stability (under 50-256°C) and water solubility. The AAPS-iron(III) complex also showed high antioxidant activity in vitro, demonstrating an additional health benefit over other typical nonantioxidant iron nutritional supplements. Furthermore, the AAPS-iron(III) complex showed high efficiency on the treatment of the iron deficiency anemia in the model rats. Therefore, the AAPS-iron(III) complex can be used as a nutritional fortifier to supply iron in industrial processing and to assist the treatment of iron deficiency anemia.

Hypoglycemic and Hypolipidemic Effects of Glucomannan Extracted from Konjac on Type 2 Diabetic Rats

Diabetes and its complications are one of the most concerned metabolic diseases worldwide and threaten human health severely. Hypoglycemic and hypolipidemic effects of glucomannan extracted from konjac on high-fat diet and streptozocin-induced type 2 diabetic rats were evaluated in this study. Administration of konjac glucomannan significantly decreased the levels of fasting blood glucose, serum insulin, glucagon-like peptide 1, and glycated serum protein. The concentrations of serum lipids, including total cholesterol, triacylglycerols, low-density lipoprotein cholesterol, and non-esterified fatty acid, were notably reduced by konjac glucomannan treatment. In addition, antioxidant capacity, pancreatic injury, and adipose cell hypertrophy were ameliorated by konjac glucomannan administration in type 2 diabetic rats. Besides, ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry-based lipidomics analysis was used to explore the improvement of lipid metabolic by konjac glucomannan treatment. The disturbance of glycerolipid (diacylglycerol, monoacylglycerol, and triacylglycerol), fatty acyl (acylcarnitine and hydroxyl fatty acid), sphingolipid (ceramide and sphingomyelin), and glycerophospholipid (phosphatidylcholine) metabolism were attenuated by the glucomannan treatment. This study provided new insights for investigating the anti-diabetic effects of konjac glucomannan and suggests that konjac glucomannan may be a promising nutraceutical for treating type 2 diabetes.

Hypoglycemic activity and mechanism of the sulfated rhamnose polysaccharides chromium(III) complex in type 2 diabetic mice

The sulfated rhamnose polysaccharides found in Enteromorpha prolifera belong to a class of unique polyanionic polysaccharides with high chelation capacity. In this study, a complex of sulfated rhamnose polysaccharides with chromium(III) (SRPC) was synthesized, and its effect on type 2 diabetes mellitus (T2DM) in mice fed a high-fat, high-sucrose diet was investigated. The molecular weight of SRPC is 4.57 kDa, and its chromium content is 28 μg/mg. Results indicated that mice treated by oral administration of SRPC (10 mg/kg and 30 mg/kg body mass per day) for 11 weeks showed significantly improved oral glucose tolerance, decreased body mass gain, reduced serum insulin levels, and increased tissue glycogen content relative to T2DM mice (p < 0.01). SRPC treatment improved glucose metabolism via activation of the IR/IRS-2/PI3K/PKB/GSK-3β signaling pathway (which is related to glycogen synthesis) and enhanced glucose transport through insulin signaling cascade-induced GLUT4 translocation. Because of its effectiveness and stability, SRPC could be used as a therapeutic agent for blood glucose control and a promising nutraceutical for T2DM treatment.