Metabolite profiling and biochemical investigation of the antidiabetic potential of Loranthus pulverulentus Wall n-butanol fraction in diabetic animal models.

ETHNOPHARMACOLOGICAL RELEVANCE: Globally, 537 million individuals are estimated to have diabetes. The traditional use of herbs for ameliorating diabetes symptoms is a common practice in Pakistan and use of Loranthus pulverulentus Wall (L. pulverulentus) by local people in Azad Jammu and Kashmir has been reported. AIM OF THE STUDY: In the present study, the antidiabetic potential of standardized n-butanol fraction of leaves of L. pulverulentus Wall, which is a parasite of Dalbergia sisso Roxb was assessed in both alloxan (ALX) and streptozotocin (STZ) diabetic animal models. MATERIALS AND METHODS: Chemical characterization of BF was performed using HPLC, GCMS and UHPLC-MS. The effect of the fraction (250 mg/kg) on insulin, plasma free fatty acids, L-lactate, pyruvate, MDA, HbA1c and glycogen levels in ALX and STZ animal models was determined. Liver and renal profiles were analyzed in the STZ model. Toxicological studies were performed by hemolytic, Ames mutagenicity, DNA protection, and thrombolytic assays. Histopathological analysis of the pancreas, liver, and kidney was performed. RESULTS: BF demonstrated highly significant (p < 0.001) antidiabetic potential in both diabetic models. BF significantly (p < 0.05) improved OGTT results in alloxanized diabetic mice and blocked the absorption of glucose from the gut. A significant (p < 0.001) increase in insulin levels and glycogen content in liver tissue and a decrease in plasma FFA, MDA, HbA1c, L-lactate, and pyruvate levels in STZ-diabetic mice were recorded. GC-MS and chromatographic analysis showed the presence of catechin, eugenol, longifolene, caryophyllene, Ar-tumerone and Geranyl-alpha-terpinene. Various metabolites with antidiabetic potential, including 4-hydroxycinnamyl alcohol 4-D-glucoside, zingerone glucoside, trans-trismethoxy resveratrol-d4, epigallocatechin 3-O-cinnamate, and ß-glucogallin, were identified using UHPLC-MS. Animals treated with BF showed marked improvements in cellular structures of the pancreas, liver and kidneys. This fraction is non-mutagenic and protects the DNA. CONCLUSION: The experimental fraction contained potential antidiabetic bioactive compounds responsible for alleviating diabetes-associated biochemical dysregulation. The fraction increased insulin levels and enhanced glycogen storage in muscles and the liver. It blocked glucose absorption from the intestine and substantially decreased HbA1c, lactate, pyruvate, free fatty acids, lipid, liver and kidney damage. Therefore, the use of BF for the treatment of type-2 diabetes may be beneficial.

Antidiabetic effect of Ardisia elliptica extract and its mechanisms of action in STZ-NA-induced diabetic rat model via 1H-NMR-based metabolomics.

ETHNOPHARMACOLOGICAL RELEVANCE: Ardisia elliptica Thunb. (AE) (Primulaceae) is a medicinal plant found in the Malay Peninsula and has been traditionally used to treat diabetes. However, limited studies to date in providing scientific evidence to support the antidiabetic efficacy of this plant by in-vitro and in-vivo models. AIM OF THE STUDY: To investigate the anti-hyperglycemic potential of AE through in-vitro enzymatic activities and streptozotocin-nicotinamide (STZ-NA) induced diabetic rat models using proton-nuclear magnetic resonance (1H-NMR)-based metabolomics approach. MATERIALS AND METHODS: Anti-α-amylase and anti-α-glucosidase activities of the hydroethanolic extracts of AE were evaluated. The absolute quantification of bioactive constituents, using ultra-high performance liquid chromatography (UHPLC) was performed for the most active extract. Three different dosage levels of the AE extract were orally administered for 4 weeks consecutively in STZ-NA induced diabetic rats. Physical assessments, biochemical analysis, and an untargeted 1H-NMR-based metabolomics analysis of the urine and serum were carried out on the animal model. RESULTS: Type 2 diabetes mellitus (T2DM) rat model was successfully developed based on the clear separation observed between the STZ-NA induced diabetic and normal non-diabetic groups. Discriminating biomarkers included glucose, citrate, succinate, allantoin, hippurate, 2-oxoglutarate, and 3-hydroxybutyrate, as determined through an orthogonal partial least squares-discriminant analysis (OPLS-DA) model. A treatment dosage of 250 mg/kg body weight (BW) of standardized 70% ethanolic AE extract mitigated increase in serum glucose, creatinine, and urea levels, providing treatment levels comparable to that obtained using metformin, with flavonoids primarily contribute to the anti-hyperglycemic activities. Urinary metabolomics disclosed that the following disturbed metabolism pathways: the citrate cycle (TCA cycle), butanoate metabolism, glycolysis and gluconeogenesis, pyruvate metabolism, and synthesis and degradation of ketone bodies, were ameliorated after treatment with the standardized AE extract. CONCLUSIONS: This study demonstrated the first attempt at revealing the therapeutic effect of oral treatment with 250 mg/kg BW of standardized AE extract on chemically induced T2DM rats. The present study provides scientific evidence supporting the ethnomedicinal use of Ardisia elliptica and further advances the understanding of the fundamental molecular mechanisms affected by this herbal antidote.

Brewers spent grain protein hydrolysate as a functional ingredient for muffins: Antioxidant, antidiabetic, and sensory evaluation.

This study assessed the fortification of muffins with 2, 4, and 6 % of brewer's spent grain protein hydrolysates to enhance their in vitro antioxidant, α-glucosidase, and α-amylase inhibitory activities. In addition, oxidative stability, hardness, color and sensory properties of fortified muffins were investigated. The fortification of muffin formulations with 6 % hydrolysates increased antioxidant activity six times higher than that of the control sample. As the hydrolysate increased to 6 %, the α-amylase and α-glucosidase inhibition also increased to 88 and 40 %, respectively. The 6 % fortified muffins exhibited lower peroxide and thiobarbituric acid values during a 14 day storage than the control muffins, while higher hydrolysate levels darkened the color and softened the texture. Sensory evaluation indicated that muffins with 2% hydrolysates achieved similar overall acceptance as the control. It can be concluded that brewer's spent grain hydrolysate is suitable for functional bakery products.

Exploring the hypoglycaemic efficacy of bio-accessed antioxidative polyphenolics in thermally processed Cucumis dipsaceus fruits - An in vitro and in silico study.

Inhibition of breakdown of dietary carbohydrates, by controlling the postprandial activity of diabetic enzymes through fruit polyphenolics can help downregulate the effects of Type 2 Diabetes Mellitus (T2DM). The study focuses on deciphering the induction of hyperglycaemic control by bio-accessed anti-oxidative polyphenols of Cucumic dipsaceus fruits. Chiefly, we examined the antioxidant activity of bio-accessed polyphenols of C. dipsaceus fruits (DPPH: ME (GDE)-66.26 %; ABTS: FE (IDE)-1963.83 µM TEAC/mg extract; Phosphomolybdenum reduction: FE (IDE)- 64.95 mg AAEAC/g extract). To add more significance, the anti-diabetic activity was predetermined by in silico docking analyses (Pseudojervine - -5.43; Squalene- -10.41) and was concurrently confirmed by in vitro studies (α amylase inhibition: ME (GDE) - 69.58 %; α glucosidase inhibition: FE (UDE)- 88.67 %). A higher bio-accessibility of rutin (37.92 mg/g ODE) and gallic acid (8.36 mg/g ODE) was observed after quantification by HPLC, which confirmed the correlation between anti-diabetic activity and C. dipsaceus fruit phenolic compounds.

Discovery of triazole tethered thymol/carvacrol-coumarin hybrids as new class of α-glucosidase inhibitors with potent in vivo antihyperglycemic activities.

Keeping in view the inhibitory potential of monoterpenes thymol and carvacrol as well as coumarin nucleus against α-glucosidase, novel series of thymol/carvacrol-coumarin hybrids was designed, synthesized and evaluated for α-glucosidase inhibitory potential. Among the series of hybrid molecules, AS14 with IC50 value of 4.32 ± 0.11 µM was selective α-glucosidase inhibitor over α-amylase (IC50 = 37.36 ± 0.84 µM). AS14 was non-toxic toward mouse normal fibroblast cells (L929: IC50 > 100 µM). Molecular docking and dynamic simulation studies confirmed desired interactions of AS14 with α-glucosidase responsible for the inhibition of its catalysis capabilities. Acute oral toxicity study confirmed AS14 as safer molecule for in vivo pharmacological investigations with LD50 value of 300 mg/kg. AS14 also showed acute hypoglycaemic effects [reduction in blood glucose levels at 1 h of administration in maltose loading test (at 10 and 20 mg/kg by 62.65 % and 70.12 %) and sucrose loading test (at 10 and 20 mg/kg by 59.65 % and 60.23 %), respectively] as well as long term (28 days) fasting blood glucose reduction (At day 28: 10 mg/kg = 54.69 % and 20 mg/kg = 62.23 % reduction in fasting blood glucose levels) capabilities in streptozotocin induced diabetic rats. Overall study represents, AS14 as potential α-glucosidase inhibitor with adequate efficacy and safety profile and act as an effective hit lead for the further development of potent and safer α-glucosidase inhibitors for the management of postprandial hyperglycemia in diabetic patients.

Analysis of Hypoglycemic Drugs by Liquid Chromatography-Tandem Mass Spectrometry.

A rapid and simple method to measure oral hypoglycemic agents is essential in the evaluation of a patient with spontaneous hypoglycemia. As a result, a robust high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed for the qualitative detection of first-generation sulfonylureas (e.g., chlorpropamide, tolazamide, and tolbutamide), second-generation sulfonylureas (e.g., glimepiride, glipizide, and glyburide), meglitinides (e.g., repaglinide, nateglinide), and thiazolidinediones (e.g., rosiglitazone and pioglitazone). HPLC involved a C8 column and MS/MS was used in electrospray ionization (ESI) positive mode. Identification of all compounds was made using various multiple-reaction monitoring (MRMs). Isotopic labeled chlorpropamide-d4, glimepiride-d5, glyburide-d11, nateglinide-d5, repaglinide-ethyl-d5, rosiglitazone-d3, and zomepirac were used as the internal standards. The cutoffs for each drug were as follows: chlorpropamide 100 ng/mL, tolazamide 50 ng/mL, tolbutamide 20 ng/mL, glimepiride 20 ng/mL, glipizide 5 ng/mL, glyburide 5 ng/mL, repaglinide 5 ng/mL, rosiglitazone 20 ng/mL, pioglitazone 20 ng/mL, and nateglinide 5 ng/mL.

Role of polyphenols in the management of diabetic complications.

BACKGROUND: Diabetes Mellitus is an endocrine disorder that will affect, about 693 million adults by 2045 worldwide, (>50% increase from 2017). The conventional treatment of the disease, include the oral hypoglycemic drugs which are given in combination with other drugs and are known to possess various adverse effects like gastrointestinal disturbance, nausea, water retention etc. PURPOSE: Due to the urgent need of combating this disorder without side effects, the alternative and complementary therapies should be explored due to their natural origins and comparable safety. Herbal sources serve as new leads, due to the presence of phytoconstituents with potential therapeutic properties, efficacy and safety. In this review, we tried to summarise the polyphenolic phytoconstituents effective in the treatment of diabetic complications. METHODS: A systematic literature search was conducted using 4 databases (Google scholar, Pubmed, Scopus, Embase) for the identification of relevant data. Search was performed using various key words such as "diabetes", "polyphenols", "marine sources","anti-diabetic polyphenols". The in vitro studies involving the cell lines used in diabetes and animal models were also considered for inclusion. Additional research papers were identified by reviewing abstracts, scrutinizing reference lists, and reviewing previously published review articles. RESULTS: Polyphenols, a group of phytoconstituents are known worldwide for their tremendous antioxidant potential. So, various research groups have explored their mechanism and therapeutic value in diabetic complications, to improve the insulin sensitivity and glucose metabolism, in controlling the glycemic conditions. CONCLUSION: Polyphenols exhibit effective therapeutic potential in managing diabetic complications through their multifaceted mechanism of action. They exhibit antioxidative, anti-inflammatory, and anti-glycemic properties, which collectively contribute to their beneficial effects in mitigating diabetic complications. Thus, the inclusion of polyphenols into the diet, may be cosidered as an approach of managing diabetes on long term basis. In this review, we have tried to identify polyphenols effective in diabetes and summarize their mechanism of action along with their potential, for the treatment of diabetic complications.

Effect of Porphyra haitanensis polyphenols from different harvest periods on hypoglycaemic activity based on in vitro digestion and widely targeted metabolomic analysis.

The hypoglycemic effect of Porphyra is well known. Based on in vitro digestion and metabolomics, the bioaccessibility, antidiabetic activity and phenolic conversion of P. haitanensis were investigated at different harvests. Total polyphenol content (TPC), α-glucosidase inhibition and oxygen radical absorbance capacity (ORAC) increased with harvesting and digestion stages, reaching maximum at the fourth harvest. TPC and α-glucosidase inhibition after digestion reached 130-150 mg/g and 50-90 %, ORAC was 8.7-13.5 times higher than the undigestion. However, bioaccessibility in the first and second harvests was 10-80 % higher than other harvests. The phenolic content in the fourth harvest was up-regulated to 2-30 times than the first and mostly were citrus flavonoids. Redundancy analysis indicated significant correlation between phenolic metabolites and bioactivities in different harvests of P. haitanensis during digestion, with the strongest correlation coefficients were apigenin and genistein. This study provides reference for the application of P. haitanensis in treating type 2 diabetes.

Mulberry leaf multi-components exert hypoglycemic effects through regulation of the PI-3K/Akt insulin signaling pathway in type 2 diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Phytochemicals have unique advantages in the treatment of diabetes due to their multi-target activity and low toxicity. Mulberry leaves, a traditional Chinese herbal medicine, have been used in the prevention and treatment of diabetes for centuries. The main active ingredients in mulberry leaves with regards to the hypoglycemic effect are 1-deoxynojirimycin, flavonoids, and polysaccharides. However, the combined hypoglycemic effects and mechanisms of mulberry leaf multi-components remain unclear. AIM OF THE STUDY: This study explored the anti-diabetic effects of mulberry leaf multi-components (MMC) and the role of the PI-3K/Akt insulin signalling pathway in improving insulin resistance. MATERIALS AND METHODS: The main chemical components of MMC were analyzed using the phenol-sulfuric acid method, aluminum nitrate-sodium nitrite method, and HPLC-ultraviolet/fluorescence detection method. The T2DM rat model was created via feeding a high-fat diet and peritoneal injection of streptozotocin. T2DM rats were divided into four groups: model, model plus metformin, model plus low-dose, and model plus high-dose MMC groups (100 and 200 mg/kg body weight/day, respectively), and plus normal group for a total of five groups. MMC was administered by oral gavage for six weeks. Fasting blood glucose and serum lipid profiles were measured using a glucometer and an automatic biochemistry analyzer, respectively. Serum insulin and adipocytokine levels were analyzed by ELISA. Hepatic glucose metabolizing enzyme activity was evaluated by ELISA and the double antibody sandwich method. Expression of PI-3K/Akt signalling pathway proteins was analyzed by RT-PCR and Western blotting. RESULTS: Extracted 1-deoxynojirimycin, flavonoid, and polysaccharide purity was 70.40%, 52.34%, and 32.60%, respectively. These components were then mixed at a ratio of 1:6:8 to form MMC. MMC significantly reduced serum glucose, insulin, and lipid levels. In diabetic rats, MMC enhanced insulin sensitivity and alleviated inflammatory and oxidative damage by lowing adipocytokine levels and increasing anti-oxidative enzyme activity. Insulin resistance was also mitigated. MMC regulated the activity of key downstream enzymes of hepatic glucose metabolism via activating the expression of PI-3K, Akt, PDX-1, and GLUT4 at the mRNA and protein levels, thereby correcting hepatic glucolipid metabolism disorders and exerting a hypoglycemic effect. CONCLUSION: MMC ameliorated hepatic glucolipid metabolism disorders and improved insulin resistance in T2DM rats by activating the PI-3K/Akt signaling pathway. These results highlight the multi-component, multi-target, and combined effects of MMC, and suggest it may be further developed as a hypoglycemic drug.

Combination therapy with kidney protective therapies: optimizing the benefits?

PURPOSE OF REVIEW: Recent advances in the treatment of chronic kidney disease (CKD) have led to the development of several new agents that are kidney protective, particularly in people with diabetes. These agents include sodium/glucose cotransporter-2 inhibitors (SGLT-2 inhibitors), mineralocorticoid receptor antagonists (MRAs), and glucagon-like peptide-1 receptor agonists (GLP-1RAs). This review summarizes the available data regarding the effects of using these therapies in combination. RECENT FINDINGS: There is convincing evidence that SGLT-2 inhibitors and MRAs individually improve kidney function and reduce the risk of cardiovascular events in people with CKD, especially diabetic CKD. There is some evidence that GLP-1RAs may be beneficial, but further studies are needed.The available data support an additive kidney and cardiovascular benefit using combination therapy with SGLT-2 inhibitors and MRAs, and possibly with SGLT2 inhibitors and GLP-1RAs, but more long-term data are needed. The currently available data suggest that combining these agents would likely be beneficial and may be an appropriate long-term strategy. SUMMARY: Several new agents are useful in slowing the progress of CKD. Further research to identify which combinations of agents work best together and which combinations are most effective for people with different characteristics, in order to personalize treatment and improve outcomes for people with CKD, should be a priority.

Synthesis and evaluation of 2-phenylamino-1, 4-naphthoquinones derivatives as potential hypoglycaemic agents / Síntese e avaliação de derivados de 2-fenilamino-1, 4-naftoquinonas como potenciais agentes hipoglicemiantes

Due to the severe side effects revealed by most of the currently used antidiabetic medicines, search for finding new and safe drugs to manage diabetes is continued. Naphthoquinones possessing strong antioxidant properties have been employed as candidates for diabetes therapy. Present study is aimed at finding the antioxidant and hypoglycaemic potential of some novel derivatives of 2-phenylamino-1,4-naphthoquinones (PAN) including chloro, nitro, methyl and bromo (5a-d) derivatives synthesized by single pot experiment. Product crystals were purified by TLC and characterized by FT-IR. The antioxidant potential of the compounds was assayed through DPPH radical scavenging and reducing power activities noted as UV-vis. absorbance. The DPPH assay has showed the powerful antioxidant activity of nitro and bromo derivatives, while the nitro derivative showed the significant reduction potential towards FRAP assay. Hypoglycaemic potential of the compounds was studied in rat animal model. All synthesized compounds revealed better hypoglycaemic activity; however, the chloro-derivative exhibited the more potent hypoglycaemic activity showing about 43% reduction in the mean blood glucose levels of the treated animals. As the bioreduction of naphthoquinones may be influenced by changing its redox properties, it has been noticed that the e-donating resonance effect (+R) of 'chloro' group has shown the significant effects on biological activity through stabalization of its imine form which limits the potential of generation of free radicals during bioreduction of quinones and thus has been proposed as the reason of its hypoglycaemic activity. Future studies employing the properties of e-donating groups of PAN may optimize the drug-receptor interaction for better drug designing and drug development strategies against diabetes and also for the clinical trials.

Em razão dos graves efeitos colaterais causados pela maioria dos medicamentos antidiabéticos atualmente utilizados, continua a busca por novos medicamentos seguros para o controle do diabetes. As naftoquinonas, que possuem fortes propriedades antioxidantes, têm sido empregadas como candidatas à terapia do diabetes. O presente estudo visa encontrar o potencial antioxidante e hipoglicemiante de alguns novos derivados de 2-fenilamino-1,4-naftoquinonas (PAN), incluindo derivados de cloro, nitro, metil e bromo (5a-d) sintetizados por experimento em pote único. Os cristais do produto foram purificados por TLC e caracterizados por FT-IR. O potencial antioxidante dos compostos foi testado por meio de atividades de sequestro de radicais DPPH e redução de energia observada como absorção no UV-vis. O ensaio DPPH mostrou a poderosa atividade antioxidante dos derivados nitro e bromo, enquanto o derivado nitro mostrou o potencial de redução significativo para o ensaio FRAP. O potencial hipoglicêmico dos compostos foi estudado em modelo animal de rato. Todos os compostos sintetizados revelaram melhor atividade hipoglicemiante; no entanto, o derivado cloro apresentou atividade hipoglicêmica mais potente, com redução de 43% nos níveis médios de glicose no sangue dos animais tratados. Como a biorredução de naftoquinonas pode ser influenciada pela alteração de suas propriedades redox, notou-se que o efeito da doação eletrônica por ressonância (+R) do grupo "cloro" tem sido significativo na atividade biológica por meio da estabilização de sua forma imina, que limita o potencial de geração de radicais livres durante a biorredução de quinonas, e, portanto, tem sido proposto como a razão de sua atividade hipoglicemiante. Estudos futuros empregando as propriedades de grupos de doação eletrônica de PAN podem otimizar a interação droga-receptor para melhor planejamento de medicamentos e estratégias de desenvolvimento de medicamentos contra o diabetes e também para os ensaios clínicos.

Hyperglycemia effect of Pinctada martensii hydrolysate in diabetic db/db mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Pinctada martensii (Dunker) and other marine shellfish flesh have been traditionally used in China as folk remedies regulate blood sugar. AIM OF THE STUDY: To investigate the main active constituents and the pharmacological mechanism of Pinctada martensii flesh enzymatic hydrolysate (PMH) against T2DM. MATERIALS AND METHODS: The hypoglycemic activity of enzymolysis peptides from Pinctada martensii was evaluated by using db/db mice, through the influence of glycemic index, blood lipid and key protein expression of PI3K-Akt pathway. In addition, label-free quantitative proteomics was used to screen the key proteins for Pinctada martensii hydrolysate (PMH) to improve T2DM, and Western blot and qRT-PCR were used to verify the expression difference of differential proteins at protein and mRNA levels between different groups. RESULTS: PMH were prepared and characterized. In vivo investigations revealed that the PMH could regulate blood glucose and improve glucose tolerance and insulin tolerance, reduced serum total cholesterol, triglyceride, low-density lipoprotein cholesterol levels and increase high-density lipoprotein cholesterol levels in db/db mice. Western blot results showed that PMH could up-regulate IRS-1, P-PI3K/PI3K and P-Akt/Akt levels in db/db mice. Label-free quantitative proteomic approach was used to analyze the proteome in db/db mouse liver, 231 proteins were reversed significantly (p < 0.05), and these proteins were involved in oxidative phosphorylation, glycolysis/gluconeogenesis and other pathways. Further screened 15 proteins with FC > 1.2 could be enriched in the retinol metabolic pathway, and the proteins in this pathway were also verified. CONCLUSIONS: PMH has hypoglycemic effect and can be used as a potential natural T2DM intervener. The hypoglycemic activity of PMH is related to its regulation of the PI3K/AKT pathway. The PI3K/AKT pathway and the retinol pathway are considered as another potential pathway for PMH to exert hypoglycemic effects.

Safety and antidiabetic activity of Lagenaria siceraria (Molina) Standl. juice in streptozotocin -induced diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Diabetes and its complications have overwhelmed India's healthcare system. Current therapies are expensive and have adverse side effects, thus dietary changes and alternative treatments are needed. Lagenaria siceraria (Molina) Standl. Juice is used mainly for its nutritional and medicinal values, however toxicity of the juice and antidiabetic effects have been poorly characterized. AIM OF THE STUDY: To investigate the toxicity, anti-diabetic and anti-inflammatory efficacy of Lagenaria siceraria (Molina) Standl. (LS) juice. MATERIALS AND METHODS: In vitro antidiabetic (α-glucosidase, α-amylase and DPP-4 inhibitory) activities were screened using standard procedures. The glucose uptake test was carried out by using L6 rat skeletal muscle cell line. In vivo sub-acute toxicity of LS juice was assessed on Wistar rats. Wistar rats were induced with diabetes by a single intraperitoneal (I.P) injection of freshly prepared streptozotocin (55 mg/kg body weight). The animals were randomly divided into 6 groups: normal control, untreated diabetic control, diabetic rats. Different dose of 200 mg/kg, 400 mg/kg and 600 mg/kg body weight of LS juice were administered, one group of diabetic rats were administered with 2 IU/mL insulin. The rats were sacrificed on the 31st day of the experiment and various in vivo biochemical parameters were evaluated in the serum and tissue homogenates of diabetic rats. RESULTS: Significant dose-dependent inhibition of α-amylase (22.6%), α-glucosidase (50.13%), and DPP-4 (61.50%) activity was observed by LS juice. LS juice (10 µg/mL) increased insulin-mediated 2NBDG (2-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-yl) Amino)-2-Deoxyglucose) absorption in L6 cells. Animals treated with LS juice showed no toxicity or unfavorable pharmacological effects. Lagenaria siceraria (Molina) Standl. Juice improved glucose tolerance in diabetic rats with reduced fasting blood glucose. Lipopolysaccharide induced NF-κB, TNF-α and IL-1ß production was also decreased in rats fed with LS juice. CONCLUSION: Lagenaria siceraria (Molina) Standl. Juice has demonstrated promising anti-inflammatory properties as well as the capacity to inhibit the digestion enzymes glucosidase and amylase. Our findings thus open new avenues for further research into the antidiabetic potential of LS juice.

Study of the acetylation-induced changes in the physicochemical and functional characteristics of insoluble dietary fiber from wheat bran.

BACKGROUND: Wheat bran is rich in dietary fiber (DF), particularly insoluble dietary fiber (IDF). Although the benefits for human health following the consumption of these DFs have been documented, the lower water retention capacity (WRC) and other properties still limit the applications of DF. Therefore, the current research investigated the impact of acetylation on the changes in the corresponding physicochemical and functional properties of DF. RESULTS: The current results indicated the acetylated group restricted the alignment of the molecular chains, which led to an increased amorphous phase in the fiber structure, followed by an enhanced thermal sensitivity and a reduced crystallinity as evidenced by X-ray diffraction (XRD). Moreover, the acetylation of the IDFs enhanced the cholesterol absorption capacity, but the corresponding antioxidant capacity and cation exchange capacity were reduced, which might be due to the partial loss of the phenolic compounds onto the polysaccharides during the modification. Interestingly, a lower degree of substitution (DS) of the IDF achieved from water-acetic anhydride modification led to a higher WRC and water swelling capacity (WSC). In contrast, a higher DS from acetic anhydride modification demonstrated a greatly improved in vitro hypoglycemic performance of the IDF, including α-amylase inhibitory activity and glucose dialysis retardation index (GDRI), compared to the other samples. CONCLUSION: This study highlights a new approach to modify the functionality of IDFs via acetylation and the design of a novel IDF with hypoglycemic activity. © 2023 Society of Chemical Industry.

Mechanistic study on the inhibition of α-amylase and α-glucosidase using the extract of ultrasound-treated coffee leaves.

BACKGROUND: Our previous studies have shown that ultrasound-treated γ-aminobutyric acid (GABA)-rich coffee leaves have higher angiotensin-I-converting enzyme inhibitory activity than their untreated counterpart. However, whether they have antidiabetic activity remains unknown. In this study, we aimed to investigate the inhibitory activities of coffee leaf extracts (CLEs) prepared with ultrasound (CLE-U) or without ultrasound (CLE-NU) pretreatment on α-amylase and α-glucosidase. Subsequently, we evaluated the binding interaction between CLE-U and both enzymes using multi-spectroscopic and in silico analyses. RESULTS: Ultrasound pretreatment increased the inhibitory activities of CLE-U against α-amylase and α-glucosidase by 21.78% and 25.13%, respectively. CLE-U reversibly inhibits both enzymes, with competitive inhibition observed for α-amylase and non-competitive inhibition for α-glucosidase. The static quenching of CLE-U against both enzymes was primarily driven by hydrogen bond and van der Waals interactions. The α-helices of α-amylase and α-glucosidase were increased by 1.8% and 21.3%, respectively. Molecular docking results showed that the key differential compounds, including mangiferin, 5-caffeoylquinic acid, rutin, trigonelline, GABA, caffeine, glutamate, and others, present in coffee leaves interacted with specific amino acid residues located at the active site of α-amylase (ASP197, GLU233, and ASP300). The binding of α-glucosidase and these bioactive components involved amino acid residues, such as PHE1289, PRO1329, and GLU1397, located outside the active site. CONCLUSION: Ultrasound-treated coffee leaves are potential anti-diabetic substances, capable of preventing diabetes by inhibiting the activities of α-amylase and α-glucosidase, thus delaying starch digestion. Our study provides valuable information to elucidate the possible antidiabetic capacity of coffee leaves through the inhibition of α-amylase and α-glucosidase activities. © 2023 Society of Chemical Industry.

Effects of extraction methods on the structure and functional properties of soluble dietary fiber from blue honeysuckle (Lonicera caerulea L.) berry.

The work within this study aimed to investigate and compare the effects of compound enzyme extraction (CE), ultrasonic chemical extraction (UC) and combined fermentation extraction (CF) on the physicochemical properties, microstructure, and functional properties of soluble dietary fiber (SDF) extracted from blue honeysuckle berries. The results showed that CE-SDF had higher crystallinity (32.41%). UC-SDF had the highest yield (13.32 ± 0.80 g/100 g). CF-SDF had the maximum inhibition of α-amylase (50.82 ± 0.76%) and α-glucosidase (54.87 ± 1.25%). The in vitro hypoglycemic activity of the three SDFs was observed in the order of CF > CE > UC. Meanwhile, the purity of SDF had a strong positive correlation with its antioxidant and in vitro hypoglycemic capacities. The crystallinity of SDF was found to be positively correlated with its molecular weight and thermal properties. Additionally, the sugar composition of SDF was found to be an important factor affecting its biological activity.

Antidiabetic effects of polyherbal mixture made of Centaurium erythraea, Cichorium intybus and Potentilla erecta.

ETHNOPHARMACOLOGICAL RELEVANCE: The polyherbal mixture made of Centaurium erythraea aerial parts and Cichorium intybus roots and Potentilla erecta rhizomes has been used for centuries to treat both the primary and secondary complications of diabetes. AIM OF THE STUDY: As a continuation of our search for the most effective herbal mixture used as an ethnopharmacological remedy for diabetes, this study aimed to compare the in vitro biological activities of this polyherbal mixture and its individual ingredients, and, most importantly, to validate the ethnopharmacological value of the herbal mixture through evaluation of its phytochemical composition, its potential in vivo toxicity and its effect on diabetes complications. MATERIALS AND METHODS: Phytochemical analysis was performed using HPLC-UV. Antioxidant activity was estimated via the DPPH test. Potential cytotoxicity/anticytotoxicity was assessed using an in vitro RBCs antihemolytic assay and an in vivo sub-chronic oral toxicity method. Antidiabetic activity was evaluated using an in vitro α-amylase inhibition assay and in vivo using a chemically induced diabetic rat model. RESULTS: The HPLC-UV analysis revealed the presence of p-hydroxybenzoic acid, p-hydroxybenzoic acid derivative, catechin, five catechin derivatives, epicatechin, isoquercetin, hyperoside, rutin, four quercetin derivatives, caffeic acid, and four caffeic acid derivatives in the polyherbal mixture decoction. Treatment with the decoction has shown no toxic effects. The antioxidant and cytoprotective activities of the polyherbal mixture were higher than the reference's ones. Its antidiabetic activity was high in both in vitro and in vivo studies. Fourteen days of treatment with the decoction (15 g/kg) completely normalized blood glucose levels of diabetic animals, while treatments with insulin and glimepiride only slightly lowered glycemic values. In addition, lipid status of treated animals as well as levels of serum AST, ALT, ALP, creatinine, urea and MDA were completely normalized. In addition, the polyherbal mixture completely restored the histopathological changes of the liver, kidneys and all four Cornu ammonis regions of the hippocampus. CONCLUSIONS: The polyherbal mixture was effective in the prevention of both primary and secondary diabetic complications such as hyperlipidemia, increased lipid peroxidation, non-alcoholic fatty liver disease, nephropathy and neurodegeneration.

Revealing the improvement of diabetes by Si Wei Jiang Huang Tang San through ERK/HIF1α signaling pathway via network pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: Si Wei Jiang Huang Tang San (SWJHTS) is a traditional Tibetan medicine prescription for the treatment of urethritis, frequent urination, and urgency, composed of four traditional Chinese medicines: Curcumae longae rhizoma, Berberidis cortex, Tribuli fructus, and Phyllanthi fructus. However, whether SWJHTS exhibits hypoglycemic efficacy and its specific mechanism remain unclear. AIM OF THE STUDY: In this study, we aimed to investigate the anti-diabetic effects of SWJHTS and elucidate the underlying mechanism. MATERIALS AND METHODS: HPLC-MS method was used to identify the key components of four kinds of traditional Chinese medicine (Curcumae longae rhizoma, Berberidis cortex., Tribuli fructus, and Phyllanthi fructus) which composed SWJHTS and determine their structure. Normal mice and 145 mg/kg STZ-induced type 1 diabetic mice were treated with three doses of SWJTHS by oral gavage. Body weight, 24h food and water intake, fasting blood glucose, glucose tolerance and other indicators were measured to evaluate the hypoglycemic effect of SWJHTS. OMIM, Genecards and other databases were used to collect targets of diabetes, and HPLC-MS results and TCMSP database information were used to collect drug component targets. Bioinformatics methods such as pathway enrichment analysis and molecular docking were used to predict the key targets of SWJHTS. The gene and protein expressions of HIF1α and ERK signaling pathways in HepG2 cells treated with SWJHTS were detected by RT-PCR and Western blot. RESULTS: A total of 181 components were identified, including curcumin, palmatine, and berberine, etc. The in vivo studies showed that SWJHTS could significantly lower fasting blood glucose levels and improve the symptoms of polydipsia, polyphagia, and polyuria in diabetic mice. Furthermore, we identified HIF1α as the potential key target of SWJHTS against diabetes utilizing network pharmacology approach and in silico molecular docking. Subsequently, we experimentally confirmed that SWJHTS could suppress the high glucose-induced upregulation of HIF1α expression, which mediated the glucose consumption in HepG2 cells. The ERK signaling pathway was further found to be activated by the SWJHTS as the upstream of HIF1α. CONCLUSIONS: SWJHTS can improve glucose metabolism by targeting the ERK/HIF1α signaling pathway; hence might be a prospective anti-diabetic drug for diabetic patients as traditional Tibetan medicine.

Phytochemical analysis, antioxidant and hypoglycemic activities of a methanol extract from Stachys brachyclada de Noé ex Coss. leaves.

Stachys brachyclada de Noé ex Coss. (Lamiaceae) is a quite rare medicinal plant endemic to the Mediterranean basin. In this study, seven secondary metabolites from a methanol extract of its leaves have been isolated and identified by a combination of chromatographic and spectroscopic methods (1D and 2D NMR experiments and ESIMS analysis). They include one ethyl 4-hydroxybenzoate (1), three acylated flavone glycosides (2-4), one diapigenin derivative (5) and two flavone aglycones (6-7). Stachysetin (5) was found the major compound of the extract (74.0 mg/g of dry matter). Moreover, the produced extract showed the ability in inhibiting the α-glucosidase enzyme (IC50 = 13.7 µg/mL), in quenching the radical 1,1-diphenyl-2-picrylhydrazyl (EC50 = 74.6 µg/mL), and in reducing the intracellular oxidative stress level in Human Dermal Fibroblast (64% inhibition at 50 µg/mL).

Age disparities in glucose-lowering treatment for Danish people with type 2 diabetes: a cross-sectional study between 2019 and 2020.

BACKGROUND: The pharmacotherapeutic guidelines for type 2 diabetes have changed considerably during the past decades. SGLT2 inhibitors and GLP-1 receptor agonists have emerged as first-line agents by preventing cardiovascular events within a few years of treatment. In contrast, sulphonylureas and insulin have been deprioritised due to less beneficial effects and the risk of hypoglycaemia-particularly in older people who are frail. We hypothesised that medications with a high risk of hypoglycaemia were used more often in older people compared with younger people. METHODS: In a nationwide cohort of people with type 2 diabetes in Denmark from 2019 to 2020, we described the use of specific glucose-lowering medications in relation to age and glycated haemoglobin A1C (HbA1c) by descriptive statistics and regression models adjusted for sex, socioeconomic factors, renal function, and several comorbidities. FINDINGS: Among 290 890 people with type 2 diabetes, glucose-lowering medication usage peaked at age 70 years. Increasing age was associated with relatively less use of metformin, GLP-1 receptor agonists, and SGLT2 inhibitors and more use of basal insulin, DDP-4 inhibitors, and sulphonylureas. When comparing 80-year-olds with 60-year-olds at similar HbA1c levels of 6·5% (48 mmol/mol), 80-year-olds used 8% (95% CI 7-10%) fewer glucose-lowering medications, were 55% less likely to receive GLP-1 receptor agonists or SGLT2 inhibitors (relative ratio 0·45, 95% CI 0·42-0·48), and 65% more likely to receive sulphonylureas (1·65, 1·54-1·76). Among 23 032 individuals aged 80 years or older with HbA1c levels of less than 6·5% (<48 mmol/mol), 2291 (10%) used sulphonylureas or insulin. INTERPRETATION: In Danish people with type 2 diabetes, the likelihood of using glucose-lowering medications with a high risk of hypoglycaemia (eg, sulphonylureas and basal insulin) increased with age, whereas the likelihood of using GLP-1 receptor agonists and SGLT2 inhibitors decreased. Some people aged 80 years or older with an HbA1c level of less than 6·5% (48 mmol/mol) were potentially overtreated with sulphonylureas or insulin. These findings emphasise the importance of frequently re-evaluating glucose-lowering treatments. FUNDING: None. TRANSLATION: For the Danish translation of the abstract see Supplementary Materials section.