Purifi cation, characterization and hypoglycemic activity of glycoproteins obtained from pea (Pisum sativum L.)

This study aimed to isolate and characterize the structures of glycoproteins from peas and determine their hypoglycemic activity.The crude pea glycoproteins(PGP)were extracted by hot water and purified by diethylaminoethyl(DEAE)-Sepharose chromatography and Sephadex G-100 size-exclusion chromatography in sequence.Then three main fractions were obtained,namely PGP1,PGP2 and PGP3,with molecular weights of 897615,846740 and 1194692 Da,respectively.The physical and chemical properties of the three fractions were evaluated and compared by Fourier transform infrared spectroscopy(FT-IR),nuclear magnetic resonance(NMR),scanning electron microscope(SEM),high performance liquid chromatography(HPLC)and other analytical techniques.The fraction PGP2 with the highest hypoglycemic activity,was screened using the Caco-2 monolayer cell model.It can inhibit the uptake of glucose in the small intestine,as well as the activities of maltase and sucrase.After simulated gastrointestinal digestion,PGP2 signifi cantly enhanced the inhibitory effect of α-glucosidase,and slightly reduced the inhibitory ability ofα-amylase.In summary,PGP2 possessed strong hypoglycemic activity after digestion.These results indicated that PGP2 has the potential to be developed into a functional food or natural medicine for the treatment of type 2 diabetes mellitus.

Synthesis, hypoglycemic activity and toxicity study of vanadium oxide complex with genistein

OBJECTIVE Vanadium is a necessary trace element in the human body and has a certain role in the treatment and prevention of diabetes.Organic vanadium is more easily absorbed and less toxic than inorganic vanadium.Thus,in this study,vanadium complex was synthesized from genistein which had good hypoglycemic activity and inor⁃ganic vanadium element,and its hypoglycemic activity and acute oral toxicity were studied.METHODS The vanadium genistein complex was synthesized by chelating vanadium with genistein in methanol and its structure was determined by LC-MS,atomic absorption spectroscopy,UV-visible spectroscopy,elemental and thermodynamic analysis.The antidiabetic activity of the complex was assessed in db/db mice and C57 mice by daily oral gavage for 4 weeks.These db/db mice were divided into test groups〔high(30 mg·kg^-1),medium(20 mg·kg^-1)and low(10 mg·kg^-1)dose group〕,model group,genistein group,inorganic vanadium group,each group of 8;8 C57 mice was for normal control group.The acute toxicity test was carried out on KM mice with this complex by a maximum limit dose method.Randomly 20 healthy KM mice were divided into negative control group and test group,each group of 10,male and female half.RESULTS The molecular structure of this complex was inferred as a complex(VL2)formed by two ligands and one vanadium element.It was found that its hypoglycemic activity was better than that of genistein and inorganic vanadium.The hypoglycemic activity of the high dose group was better than that of the medium dose group and low dose group.The complex can signifi⁃cantly improve the body mass of db/db mice,fasting blood glucose,random blood glucose,liver/body,kidney/body,and the performance of oral glucose tolerance test and insulin tolerance test in db/db mice.The morphology of liver,kidney,pancreas and skeletal muscle also had obvious improvement and repair.Effect on serum index of db/db mice showed that,total cholesterol,triglyceride,low-density lipoprotein cholesterol had no significant improvement compared with the model group,but high-density lipoprotein cholesterol of complex group had significant improvement compared with the model group.In addition,this complex did not produce any hazardous symptoms or deaths in acute oral toxicity test.CONCLUSION complex has good hypoglycemic activity in vivo,and did not have the potential toxicity.This would provide an important reference for the development of functional hypoglycemic foods.

An UPLC-MS/MS application to investigate chemical compositions in the ethanol extract with hypoglycemic activity from Zingiber striolatum Diels

Zingiber striolatum Diels （Zingiberaceae） is an edible plant resource in the Chinese folk with special efficacy in relieving diabetes and constipation, which has been documented in the Compendium ofMateria Medica. However, its hypoglycemic activity and constituents have not been reported yet. In the present study, we evaluated the hypoglycemic activity of Z. striolatum in insulin-resistant HepG2 cells, and we developed ultra performance liquid chromatography coupled with tandem mass spectrometry （UPLC-MS/MS） based chemical profiling method for rapid analysis of Z. striolatum. As a result, the ethanol extract from Z. striolatum showed significant hypoglycemic activity in HepG2 cells, and 22 flavonoids compounds were tentatively characterized by comparing the retention time and mass spectrometry data. In conclusion, the method of hypoglycemic screening in insulin-resistant HepG2 cells coupled with UPLC-MS/MS is a feasible and credible technique to separate and identify the active constituents in complex matrices of traditional Chinese medicine.

Role of semi-purified andrographolide from Andrographis paniculata extract as nano-phytovesicular carrier for enhancing oral absorption and hypoglycemic activity

Objective:Andrographis paniculata is a well-known medicinal plant in Southeast Asia,India and China.The plant contains andrographolide(AN),a very important phytochemical used in various health problems.However,AN is low in oral absorption bioavailability of AN due to the rapid clearance and high protein binding capacity.Methods:The present study was aimed to develop a nano-phytovesicular formulation of semi-purified AN extracts from a naturally occurring phospholipid(soya phosphatidylcholine)in order to increase the oral absorption and antihyperglycemic activity in rats.Results:The nano-phyto vesicle of semi-purified AN extracts equivalent to 25 mg/kg AN significantly protected the hyperglycemic condition of rats.The in vitro and in vivo experiments results proved that the nano-phytovesicular system of plant extracts containing AN produced better oral absorption,bioavailability and improved antihyperglycemic activity compared with that of free AN at dose of 50 mg/kg.Conclusion:Hence,the prepared semi-purified extract nano-phytovesicular system is helpful in solving the problem of rapid clearance of AN.

Metabolic enzyme inhibitory abilities, in vivo hypoglycemic ability of palmleaf raspberry fruits extracts and identification of hypoglycemic compounds

The unripe palmleaf raspberry,namely Fupenzi(FPZ),is an important medicinal and edible food.This study aims to evaluate the potential of FPZ extracts prepared with different approaches in attenuating hyperglycemia,gout,Alzheimer’s disease,and pigmentation,to obtain the enriching fraction and to identify the major active compounds.Results indicated that FPZ extracts showed weak activity against acetylcholinesterase,considerable ability against tyrosinase and xanthine oxidase,but excellent inhibition onα-glucosidase.Ultrasound-assisted 40%ethanol extract(40EUS)gave the highest phenolics content,and the bestα-glucosidase inhibition(IC_(50)=0.08μg/mL),which is 877-fold higher than that of positive control acarbose.The 40%ethanol eluting fraction of 40EUS showed the strongestα-glucosidase inhibition with the IC_(50) value of 37.79 ng/mL,it could also effectively attenuate the fasting blood glucose level and oral glucose tolerance of C57BL/6 mice.Twenty-six compounds were identified from 40%ethanol fraction by using HPLC-QTOF-MS/MS,hydrolysable tannins(including 11 ellagitannins and 4 gallotannins)were the major compounds,phenolic acids came to the second.Above results could provide important technical supporting for the further application and research of FPZ in health foods and drugs against diabetes.

Structural elucidation of mulberry leaf oligosaccharide and its selective promotion of gut microbiota to alleviate type 2 diabetes mellitus

Two oligosaccharide fractions(MLO 2-1 and 2-2)were purified from enzymatic hydrolysate of mulberry leaf polysaccharide.The results of simulated digestion showed that MLO 2-2 was a digestible oligosaccharide,which could be degraded by human digestive juice;while MLO 2-1 possessed the non-digestible property in the upper gastrointestinal tract and performed the function by regulating the gut microbiota.Hence,MLO 2-1 was selected for the further analysis.The structure of MLO 2-1 was elucidated as follow:α-T-Glcp-(1→3)-β-Glcp-(1→5)-α-Araf-(1→5)-α-Araf-1→5)-α-Araf-(1→3)-α-(2-OAc)-Glcp-1.The in vitro fecal fermentation results showed that MLO 2-1 could modulate the composition of gut microbiota.Meanwhile,MLO 2-1 was effectively metabolized by fecal bacteria to produce lactate and short chain fatty acids,especially acetate and butyrate.The specific metabolic pathways of MLO 2-1 by gut microbiota were further illuminated.Gut microbiota analysis revealed that MLO 2-1 selectively promoted the growth of Ligilactobacillus murinus,a commensal bacterium presented a reduced level in T2DM mice.Animal experiments indicated that MLO 2-1 and L.murinus exhibited hypoglycemic activities.These results demonstrated that MLO 2-1 might alleviate T2DM by selectively accelerating the proliferation of L.murinus.

Hypoglycemic effects of naturally processed Polygonum multiflorum extract in KK CgAy/J mice and its mechanism of action

In 2021,there are approximately 537 million adults ageing 20-79 years affected by diabetes worldwide and the number is rising rapidly,hence it is important to manage and control diabetes mellitus and its associated complications.Food is one of the key factors in preventing and combating diseases such as diabetes.Both as a food and an herbal medicine,Polygonum multiflorum(PM)has been used as an anti-aging tonic,for hair darkening in traditional Chinese medicine for several centuries.The recent research effort of PM has been focused on antioxidant,anti-ageing and anti-tumor properties.In the present study,we utilized the traditional processing of harvested raw PM,and identified several stilbene components and then evaluated the potential anti-diabetic effects of the processed PM extract(PME).PME(0.075%)was given to diabetic mice(KK CgAy/J)in drinking water and after 7 weeks,PME-treated mice had significantly lower glucose levels than mice in the diabetic control group(P<0.01).The mechanism was explored with ELISA and Western blotting and results suggested that the effect was through maintainingβ-cell function.

Effects of different drying methods on phenolic components and in vitro hypoglycemic activities of pulp extracts from two Chinese bayberry(Myrica rubra Sieb.et Zucc.)cultivars

The effects of two different drying methods,namely hot-air drying and freeze drying,on the phenolic profiles,antioxidant and hypoglycemic activities of pulp extracts from two main Chinese bayberry cultivars(’Biqi’or’BQ’and’Dongkui’or’DK’)were evaluated.The results showed that’BQ’bayberry provided higher total phenolic(TPC),total flavonoid(TFC)and total anthocyanin(TAC)contents than’DK’bayberry after the same drying method,while its antioxidant and hypoglycemic activities were highly affected by drying method.Freeze-dried samples possessed significantly higher TPC,TFC and TAC,and exhibited more potent antioxidant and hypoglycemic activities than hot-air dried ones(P<0.05).Freeze-dried’DK’bayberry exhibited similar antioxidant activities and a-amylase inhibitory activity,but higher a-glucosidase inhibition than freeze-dried’BQ’bayberry(P<0.05).Compared with hot-air dried samples,freeze-dried samples had significantly higher contents of cyanidin-3-O-glucoside,myricitin-3-O-rhamnoside,quercetin-3-O-galactoside,quercetin-3-O-glucoside and quercetin-3-O-rhamnoside,which had been proved to be the main contributors to the in vitro hypoglycemic activities of bayberry pulp extract.All these results demonstrate that freeze drying is more suitable for the preservation of phenolic components in the pulp extract of Chinese bayberry,and the pulp extract of freeze-dried’DK’could be applied as a potential hypoglycemic food additive.

Silkworm Extract Ameliorates Type 2 Diabetes Mellitus and Protects Pancreaticβ-cell Functions in Rats

Objective The aim of the present study was to investigate the hypoglycemic effects of silkworm extract(SE)on experimental type 2 diabetes mellitus(T2DM)rats.Methods SE was prepared by dissolving freeze-dried silkworm powder in 70%(v/v)aqueous ethanol.T2DM rats were induced by feeding them a high fat diet and an intraperitoneal injection of streptozotocin(STZ).The blood glucose,free fatty acid(FFA),malondialdehyde(MDA),tumor necrosis factor alpha(TNF-α)and superoxide dismutase(SOD)levels were detected by enzyme-linked immunosorbent assay(ELISA).The quality of SE was controlled by high performance liquid chromatography(HPLC;Agilent 1260,Agilent,USA).Hematoxylin-eosin(HE)staining was performed for histological evaluation.Antibody expression was assessed via immunohistochemistry(IHC)staining.Results SE could improve insulin resistance and islet cell function by reducing FFA,MDA and TNF-αlevels and increasing SOD level.In addition,pancreatic HE staining analysis revealed that SE has a protective effect on isletβ-cells.Conclusions The present study indicates that SE has hypoglycemic as well as pancreatic protective effects in T2DM model rats.

Hypoglycemic and antioxidant activities of Clerodendrum inerme leaf extract on streptozotocin-induced diabetic models in mice

Objective:Recently,much attention has been paid to natural product-derived compounds for antidiabetic drug discovery.More recent studies are being focused on clarifying the bioactivity of plants and derived products.The aim of the present study was to investigate the anti-oxidant and antidiabetic activities of Clerodendrum inerme leaf extract(CILE)in streptozotocin-induced diabetic mice.Methods:C.inerme leaves were analyzed for preliminary phytochemical properties and the content of total phenolic and flavonoid were determined.In vitro anti-oxidant activity was measured using DPPH assay.Streptozotocin-induced diabetic model in mice was applied for in vivo study by the effect of CILE at two dose levels(343 and 686 mg/kg b.w.).Results:The results showed that C.inerme leaves contained the major constituents of flavonoids,alkaloids,tannins,triterpenes,and saponins.CILE exhibited the total polyphenol and flavonoid content with 120.458 mg gallic acid equivalent/g dry weight and 4.494 mg hispidulin equivalent/g dry weight,respectively.The anti-oxidant activity of CILE was expressed with IC50=25.28μg/m L.CILE at the doses of343 mg/kg and 686 mg/kg after 7 d administration exerted a decrease in plasma glucose,protected the liver,kidneys against oxidation stress via increasing glutathione content in the liver,and reduced malondialdehyde content in the liver and kidneys.Pancreatic histological analysis in diabetic mice treated with CILE also showed the pancreaticβ-cells regeneration via increasing the size and number of pancreatic islets.Conclusion:These findings suggested that C.inerme leaves had potent antidiabetic and anti-oxidant activities.The results provide reliable scientific base,which is the premise for further research and development of CILE as supplements.

Submerged fermentation improves bioactivity of mulberry fruits and leaves

Objective:Mulberry(Morus spp.)fruits and leaves have been proven to possess nutraceutical properties.Due to its fast and easy growing characteristics,mulberry fruits(MF)and leaves(ML)potentially emerge as a great source of functional foods.This study aims to enhance bioactivities(antioxidant,antiinflammation,and hypoglycemic activity)of MF and ML via submerged fermentation using bacteria(Lactobacillus plantarum TAR 4),yeast(Baker’s yeast and red yeast)and fungi(Tempeh and Tapai starter).Methods:In this study,25%(mass to volume ratio)of MF and ML were fermented(48 h)with 1%(mass to volume ratio)of different microbial cultures,respectively.Effects of different fermentations on MF and ML were determined based on the changes of total phenolics(TPC),flavonoids(TFC),anthocyanins,total sugar,DPPH activity,ferric reducing antioxidant power(FRAP),albumin denaturation inhibition activity(ADI),anti-lipoxygenase activity and a-amylase inhibition activity(AI).Results:Generally,ML had higher AI than MF.However,MF exhibited higher DPPH,FRAP and antilipoxygenase activity than ML.After all forms of fermentation,DPPH and AI activity of MF and ML were increased significantly(P<0.05).However,the effects of fermentation on TPC,FRAP,ADI and antilipoxygenase activity of MF were in contrast with ML.TPC,FRAP and anti-lipoxygenase activity of ML were enhanced,but reduced in MF after fermentation.Although the effects exerted by different microorganisms in MF and ML fermentation were different,the bioactivities of MF and ML were generally improved after fermentation.Fermentation by Tempeh starter enhanced TPC(by 2-fold),FRAP(by 2.3-fold),AI(at 10%increment)and anti-lipoxygenase activity(by 5-fold)of ML,whereas Tapai fermentation effectively enhanced the DPPH(at 17%increment)and ADI(by 2-fold)activity of MF.Conclusion:Findings of this study provide an insight into the future process design of MF and ML processing into novel functional foods.

Byrsocarpus coccineus Schumach.&Thonn.(Connaraceae)叶子提取物的降血糖和抗氧化活性(英文)

AIM: Diabetes Mellitus is associated with significant morbidity and mortality worldwide. The need for enhanced efficacy and safety, and cheaper and more readily available new drugs has increased the search for new antidiabetic drugs from plants. This study was conducted to investigate the antidiabetic activity of the hydroethanolic leaf extract of B. coccineus in rats. METHODS: The effect of B. coccineus extract(100–800 mg·kg–1, p.o.) on blood glucose levels in normal and glucose loaded rats, and alloxan-induced diabetic rats was determined. After 10 days of treatment, blood samples were collected from rats for lipid and insulin profiling. Animals were thereafter sacrificed and the kidneys, heart, and liver were harvested for antioxidant indices assay. RESULTS: In normal rats, B. coccineus did not cause significant reduction in blood glucose. At the dose of 800 mg·kg–1, significant increase in blood glucose level was not observed 30 min. after glucose load. B. coccineus administered acutely did not generally produce significant reduction in blood glucose level in diabetic rats. Administered subacutely, the extract significantly reduced blood glucose level in diabetic rats from the 3rdday with peak effect observed at the dose of 800 mg·kg–1on the 10thday. The extract generally preserved in vivo antioxidant levels in the kidneys, heart, and liver, increased the level of high density lipoprotein and insulin, and reduced the level of triglycerides and low density lipoprotein compared to diabetic control. CONCLUSION: The findings in this study suggest that the hydroethanolic leaf extract Byrsocarpus coccineus possesses antidiabetic activity possibly mediated through inhibition of intestinal glucose absorption, in vivo antioxidant activity, and enhancement of regeneration of beta cells of the pancreas and insulin secretion.