Investigation of hypoglycemic,hypolipidemic and antioxidant activities of aqueous extract of Terminalia paniculata bark in diabetic rats

Objective:To investigate the hypoglycemic,hypolipidemic and antioxidant activities of aqueous extract of Terminalia paniculata bark(AETPB) in streptozotocin(STZ)-mduced diabetic rats.Methods:Acute toxicity was studied in rats after the oral administration of AETPB to determine the dose to assess hypoglycemic activity.In rats,diabetes was induced by injection of STZ(60 mg/kg,i.p.) and diabetes was confirmed 72 h after induction,and then allowed for 14 days to stabilize blood glucose level.In diabetic rats,AETPB was orally given for 28 days and its effect on blood glucose and body weight was determined on a weekly basis.At the end of the experimental day,fasting blood sample was collected to estimate the haemoglobin(Hb),glycosylated haemoglobin(HbA1c),serum creatinine,urea,serum glutamate-pyruvate transaminase(SGPT),serum glutamate-oxaloacetate transaminase(SGOT) and insulin levels. The liver and kidney were collected to determine antioxidants levels in diabetic rats.Results: Oral administration of AETPB did not exhibit toxicity and death at a dose of 2000 mg/kg.AETPB treated diabetic rats significantly(P<0.001,P<0.01 and P<0.05) reduced elevated blood glucose, HbAlc,creatinine,urea,SGPT and SGOT levels when compared with diabetic control rats.The body weight,Hb,insulin and total protein levels were significantly(P<0.001,P<0.01 and P<0.05) increased in diabetic rats treated with AETPB compared to diabetic control rats.In diabetic rats, AETPB treatment significantly reversed abnormal status of antioxidants and lipid profile levels towards near normal levels compared to diabetic control rats.Conclusions:Present study results confirm that AETPB possesses significant hypoglycemic,hypolipidemic and antioxidant activities in diabetic condition.

Antidiabetic,hypolipidemic and histopathological analysis of Dillenia indica (L.) leaves extract on alloxan induced diabetic rats

Objective:To investigate antidiabetic,hypolipidemic histopathological analysis of Dillenia indica(D.indica) methanolic leaves(DIME) extract in alloxan induced diabetic rat by administering oral doses(250 and 500 mg/kg body weight).Methods:Blood glucose levels were measured using blood glucose test strips with elegance glucometer on weekly intervals till the end of study(i.e.3 weeks).Other parameters e.g.liver profile,renal profile and total lipid levels were determined in normal and alloxan induced diabetic rats after oral administration of the extract for 21 days.Histopathological changes in diabetic rat organs(pancreas,liver and kidney) were also observed after extract treatment Results:Daily oral administration DIME(250 and 500 mg/kg body weight) and glibenclamide(10 mg/kg) showed beneficial effects on blood glucose level (P【0.001) as well as improving kidney,liver functions and hyperlipidaemia due to diabetes. The extract treatment also showed to enhanced serum insulin level and body weight of diabetic rats as compared to diabetic control group.Furthermore,the extract has a favorable effect on the histopathological changes of the pancreas,liver and kidney in alloxan induced diabetes. Conclusions:D.indica possess antidiabetic property as well improve body weight,liver profile, renal profile and total lipid levels.DIME has also favorable effect to inhibit the histopathological changes of the pancreas and kidney in alloxan induced diabetes.

Hypolipidemic,antioxidant and anti-atherosclerogenic effects of aqueous extract of Zanthoxylum heitzii stem bark in diet-induced hypercholesterolemic rats

Objective:To evaluate anti-dyslipidemic,antioxidant and anti-atherosclerogenic properties of this extract in diet-induced hypercholesterolemic rat.a model of metabolic syndrome-induced atherosclerosis and associated cardiovascular diseases.Methods:Normocholeslerolemic(NC) male rats were divided into six groups(n=10) and fed a high-cholesterol(HC) diet for 30 days(5 groups),or normal rat chow(normal control group).Rats given a HC diet also received distilled water(disease control),the potent hypocholcsterolcmic agent with antiatherosclerotic activity atorvastatin(2 mg/kg,positive control),or one of the three doses of Zanthoxylum heitzii stem bark aqueous extract tested(225,300 and 375 mg/kg) concomitantly for four months.Signs of general toxicity,body temperature and weight,and water and food intake were monitored in live animals.After sacrifice,lipid profiles and oxidative stress markers were assessed in the blood and liver,aorta,and feces,and histopathological analysis of aorta was performed.Results:Plant extract prevented the elevation of aortic total cholesterol and triglycerides,and hepatic low density lipoprotein,very low density lipoprotein,and total cholesterol.Lipid peroxidation(TBARS) was decreased and aortic atherosclerotic plaque formation prevented.Conclusions:These observations strongly suggest that stem bark aqueous extract of Zanthoxylum heitzii has anti-atherosclerogenic properties,at least partly mediated by antioxidant and hypolipidemic effects.

The antioxidant activity and hypolipidemic activity of the total flavonoids from the fruit of Rosa laevigata Michx

In the present work, the antioxidant activity in vitro and hypolipidemic activity of the total fla-vonoids (TFs) from the Rosa laevigata Michx fruit was evaluated, and the antioxidant effect in vivo was also discussed. The TFs exhibited a high scavenging effect on 2, 2-diphenyl-1- picrylhydrazyl (?DPPH) with IC50 values 0.01 mg/mL, and a stong reduce power in the test. Hyperli-pemic mice were intragastric administrated with TFs (25, 50 mg/kg/day) for 4 weeks, and fenofi-brate was used as the positive reference sub-stance. After the experiment, the levels of TC (total cholesterol), TG (triglyceride), LDL- C (low density lipoprotein-cholesterol) of the mice ad-ministrated with high-dose of TFs were mark-edly declined by 45.02%, 33.86% and 73.68%, re-spectively, while HDL-C (high density lipopro-tein-cholesterol) was significantly increased com-pared with model group. To investigate the hepatoprotective effect, histopathological assay, ALT (alanine aminotransferase), AST (aspartate aminotransefrase) and ALP (alkaline phosphatase) were also studied, and the results showed that TFs exhibited a favorable effect on liver protec-tion, of which the levels of ALT, AST and ALP were elevated by 55.85%, 29.15% and 25.68%, respectively. Furthermore, the TFs could sig-nificantly decrease the MDA (malondialdehyde) level and improve the levels of CAT (Catalas), SOD (superoxide dismutase), GSH (reduced glutathione), and GPX (glutathione peroxidase) compared with hyperlipemia mice. Our results suggested that TFs has a high antioxidant ac-tivity and hypolipidemic activity, which can be used as a potential medicine for cardiovascular diseases.

Antioxidant,Hypoglycemic and Hypolipidemic Activities of Sambucus williamsii Seed Oil

[Objectives] To explore the antioxidant activity of Sambucus williamsii seed oil. [Methods]DPPH scavenging method and Prussian blue method( total reducing power) were used. S. williamsii seed oil has antioxidant activity. In the DPPH scavenging free radical experiment,S. williamsii oil showed the ability to scavenge free radicals,and its scavenging ability had linear relationship with oil concentration( R =0. 999 6). Besides,the IC_(50) value of S. williamsii seed oil scavenging DPPH free radicals was 61. 30 ± 0. 88 mg/mL. In the total reducing power measurement experiment,the S. williamsii seed oil has a reducing ability,and its reducing ability is proportional to the oil concentration,and has the concentration dependence. Through studying the inhibitory effect of S. williamsii seed oil on α-glucosidase,the hypoglycemic activity of S. williamsii seed oil was determined. The ability of samples to inhibit α-glucosidase was judged through measuring the absorbance at 400 nm of the reaction system. [Results]In the concentration range of 1. 56-25. 00 mg/mL,the S. williamsii seed oil can effectively inhibit α-glucosidase,and the inhibition rate was 62. 66%-85. 22%. The animal in vivo experiment was used to determine the hypolipidemic activity of the S. williamsii seed oil. First,a high fat modelwas established,S. williamsii seed oil was given through intragastric administration. Then,total cholesterol( TC),triglyceride( TG),high-density lipoprotein cholesterol( HDL-C),and low density lipoprotein cholesterol( LDL-C) were measured. Through comparison of high,medium and low dose groups of S. williamsii seed oil with the high fat modelcontrol group,it was found that the TC,TG,LDL-C levels were significantly decreased( P < 0. 01) and the HDL-C levels were significantly increased( P < 0. 05),indicating that S. williamsii seed oil can effectively reduce the levels of TC,TG,LDL-C in the serum of hyperlipidemic mice,and effectively inhibit the decrease of HDL-C level,thus S. williamsii seed oil can reduce blood lipids in mice,namely,has hypolipidemic effects. In addition,the greater the dose of S. williamsii seed oil,the more obvious the effect of blood lipid levels in mice,indicating that the hypolipidemic effect of S. williamsii seed oil was dose dependent. [Conclusions] S. williamsii seed oil has reducing ability,and there is a significant dose-effect relationship in the concentration range of 2-10 mg/mL. As natural plant oil,S. williamsii seed oil has the advantages of good stability,small toxic and side effects,and strong effect,and has high value of developing new antioxidants.

The structural characteristics of dietary fibers from Tremella fuciformis and their hypolipidemic effects in mice

In this study,Tremella fuciformis residues as raw material,dietary fibers from tremella were prepared by multiple enzymes.The structure of dietary fibers from tremella was studied by Fourier transform infrared(FTIR),X-ray diffraction analysis(XRD)and scanning electron microscopy(SEM).We analyzed their lipidlowering properties in vitro(water holding,oil holding swelling cholesterol and sodium cholate binding capacitises)and the hypolipidemic effects in mice.The results showed that tremella dietary fibers presented the infrared absorption spectrum characteristics of polysaccharides and the characteristic diffraction peaks of cellulose type I.SEM results indicated that the surface of insoluble dietary fiber(IDF)was porous,while the soluble dietary fiber(SDF)was relatively compact and spongy.IDF exhibited significantly higher water holding,oil holding,and swelling binding capacities than the corresponding SDF.However,SDF exhibited significantly higher viscosity than IDF.The results showed tremella dietary fibers were significant in swelling,water holding and oil holding,cholesterol and bile acids.In vivo experiment results in mice indicated that SDF has the best effect on hyperlipidemia mice than IDF and total dietary fiber(TDF).SDF showed that the total cholesterol(TC),triglyceride(TG)and low density lipoprotein cholesterol(LDL-C)contents dropped by 28.33%,18.65%,and 48.97%,respectively,while high density lipoprotein cholesterol(HDL-C)content increased by 43.80%.Compared with the high-fat control(HCM)group,the arteriosclerosis index(AI)and liver index(LI)of the SDF group mice showed significant differences,indicating that SDF has a good auxiliary effect of lowering blood lipids.The administration of tremella fibers improved the lipid metabolism disorderly situation of hyperlipidemia mice.These results provide a reference for further research and rational development of T.fuciformis.

Investigation on tool wear and tool life prediction in micro-milling of Ti-6Al-4V

Short tool life and rapid tool wear in micromachining of hard-to-machine materials remain a barrier to the process being economically viable. In this study, standard procedures and conditions set by the ISO for tool life testing in milling were used to analyze the wear of tungsten carbide micro-end-milling tools through slot milling conducted on titanium alloy Ti-6 Al-4 V. Tool wear was characterized by flank wear rate,cutting-edge radius change, and tool volumetric change. The effect of machining parameters, such as cutting speed and feedrate, on tool wear was investigated with reference to surface roughness and geometric accuracy of the finished workpiece. Experimental data indicate different modes of tool wear throughout machining, where nonuniform flank wear and abrasive wear are the dominant wear modes. High cutting speed and low feedrate can reduce the tool wear rate and improve the tool life during micromachining.However, the low feedrate enhances the plowing effect on the cutting zone, resulting in reduced surface quality and leading to burr formation and premature tool failure. This study concludes with a proposal of tool rejection criteria for micro-milling of Ti-6 Al-4 V.

Micro-milling of Pyramid Structured Surface for Implant Application

Surface modification,as a promising approach to improve biocompatibility of biomaterials,has captured extensive close attention among many researchers.Here,micro-milling technology was used in constructing pyramid micro-structures on the surface of Ti-6Al-4Vimplant.Cutting parameters,including spindle speed,feed rate and depth of cut,were optimized to control the generation of burrs.In addition,low melting point alloy was selected to extend the boundary of the workpiece as supporting material to prevent the generation of top burrs.The surface topographies were characterized using scanning electron microscope and laser scanning microscope.Results showed that the dimension of burrs decreased with the decrease of depth of cut,and the size of burrs decreased with the increase of feed rate.Moreover,burrs nearly not appeared on both sides of the micro-grooves machined with low melting point alloy(LMPA)coating.Pyramid micro-structure on the workpiece surface was built successfully by combining optimized cutting parameters(S=35kr/min,Vf=60mm/min,ap=5μm)and LMPA coating.

Comparative study between the effect of <i>Momordica charantia</i>(wild and hybrid variety) on hypoglycemic and hypolipidemic activity of alloxan induced type 2 diabetic long-evans rats

This study was undertaken to evaluate the hypoglycemic and hypolipidemic effect of Momordica charantia (wild and hybrid variety) powder on alloxan induced type 2 diabetic male Long-Evans rats. Oral feeding of the M. charantia powder slightly decreased serum total cholesterol, triglyceride levels and LDL-cholesterol compared with wild, hybrid and standard drug. M. charantia wild variety showed more significant (p M. charantia did not show any significant effect on HDL-cholesterol and liver glycogen. Thus, results of the study prove that the wild variety of M. charantia fruit have potent antidiabetic and antilipidemic property.

Phytochemical Study and Evaluation of Cytotoxicity, Antioxidant and Hypolipidemic Properties of <i>Launaea taraxacifolia</i>Leaves Extracts on Cell Lines HepG2 and PLB985

Launaea taraxacifolia is a leafy vegetable of the family of Asteraceae (Compositae) found in several countries in West Africa including Ghana, Benin and Nigeria. The plant leaves are eaten either fresh as salad or cooked as sauces. They are also consumed as infusion to fight against several diseases including non-communicable diseases such as diabetes and hypertension. Several studies have been conducted in Ghana, Nigeria on the nutritional and medicinal values of this plant but no study has yet been conducted in Benin on the virtues of this plant. In this work we have achieved the phytochemical characterization and evaluated the cytotoxicity as well as hypolipidemic and anti-oxidant effects of the ethanol-aqueous extracts of Launaea taraxacifolia leaves. Cytotoxicity and hypolipidemic activities have been performed on HepG2 cells;the antioxidant effect has been performed on the PLB985 cells. The results showed that the ethanol-aqueous extracts of Launaea taraxacifolia leaves contained the following metabolites: catechic tannin, flavonoids, phenolic acids, mucilage and leucoanthocyanins. Only very high concentrations (>20 mg/ml) of leaves extracts are toxic for HepG2 cells. Launaea taraxacifolia leaves have significant antioxidant and hypolipidemic activities.

Hypolipidemic effect of coffee silver skin in rats fed a high-fat diet

The present study was conducted to evaluate the hypolipidemic effects of coffee silver skin(CSS)supplementation in rats fed a highfat diet(HFD).A total of 40 albino rats were used in the present study.The groups were as follows:Rats fed a normal diet,N group;high fat diet,HFD group;high fat diet+10%CSS,HFD 10;HFD+15%CSS,HFD 15;HFD+20%CSS,HFD 20;the diets were followed for 8 weeks.Blood samples were collected at the end of the experiment.At the time of sacrifice,the weights of heart,liver,kidneys,epididymal fat and retroperitoneal fat of the experimental rats with respect to body weight were recorded.The lipid parameter of the serum was recorded and liver and kidney function tests were conducted.Finally,a histopathological assay was performed on the liver and kidney tissues of the rats fed the tested diets.The weight gain of the rats fed a HFD supplemented with 10,15 and 20%CSS was∼1.05,1.08 and 1.12 times lower than that of those rats fed HFD,respectively.The incorporation of CSS at a level of 20%reduced the increase in liver,kidney,epididymal fat and retroperitoneal fat weight by 17.84,19.38,47.23 and 18.00%,respectively,compared with HFD alone.HFD administration induced considerable increases in alanine aminotransferase,aspartate aminotransferase and alkaline phosphatase activities compared with the control group.The results also indicated that the HFD-fed rats exhibited increased levels of urea,uric acid and creatinine,by∼26.38,8.40 and 6.75%,respectively,compared with the control rats.With the exception of high-density lipoprotein cholesterol,all lipid fractions increased significantly in rats fed a HFD.The administration of a HFD induced marked pathological changes in the liver and kidneys of the rats.However,the incorporation of various levels of CSS in to a HFD reduced these changes.The results of the present study illustrate that the incorporation of CSS into HFDs reduces the hyperlipidemia effect of these diets.

Hypolipidemic and Antioxidative Effects of African Star Apple Juice (Chrysophylum albidum) on Rats Fed on Diets High in Cholesterol and Oil

This study investigated the possible hypolipidemic and antioxidative effects of Chrysophylum albidum juice in rats fed on highcholesterol and fatty diets (HFCD). The juice was expressed, pasteurized and frozen until needed. Diets were formulated by mixing at different ratios. Bio-assay of the blends was carried out for a period of 28 days. Twenty five male rats were divided into five groups of five each: a normal diet group, a high-cholesterol diet group, a high Fat/Cholesterol diet with 3 ml of African Star Apple Juice group, a high Fat/Cholesterol diet with 6 ml of African Star Apple Juice group, and a high Fat/Cholesterol diet with 9 ml of African Star Apple Juice group. Blood serum, selected tissues and organs were collected and the serum lipid profile, organ histology and oxidative stress test were carried out at the end of the animal experimentation. The levels of total cholesterol, triglyceride, low density lipoprotein-cholesterol, very low density lipoprotein-cholesterol and artherogenic index obtained from rats treated with African star apple juice (3 ml, 6 ml and 9 ml) decreased significantly (P ≤ 0.05), compared respectively to the HFCD rats. The results also showed that treatment with African star apple (Chrysophylum albidum) positively changed plasma antioxidant enzyme activities and lipid profiles in cholesterol-fed rats, and thus may have potential hypolipidemic and antioxidant effects, and by inference, the antiatherogenic properties in male rats. African star apple (Chrysophylum albidum) juice could protect against oxidative stress linked atherosclerosis and decrease the atherogenic index, thereby supporting the local use of Chrysophylum albidum in the management of atherosclerosis and hypertensive conditions.

Comparison of Hypolipidemic Effect of Refined Konjac Meal With Several Common Dietary Fibers and Their Mechanisms of Action

The effects of RKM in comparison with pectin, algin and agar on lipid levels in serum and liver and on liver histopathology in rats were studied. In addition, the effects of all the tested materials on the composition and output of fecal bile acid were observed. All four kinds of dietary fiber were given at a level of 5% of diet to young male rats of Wistar strain fed on a lipid-rich diet contalning 5 % lard, 1% cholesteral and 0. 25 % cholate. All the dietary fibers tested have similar effects on serum lipid composition. In all groups, these substances prevent ed increases in total cholesterol in fasting serum, but the level of triglyceride was tmchangd.The concentrations of totaI cholesterol and triglyceride in the liver were lower in the RKM group than in the control group and the other three groups. Hepatic histopathological exami nation also showed the most significant lipotropic effect in the RKM group. The daily output of fecal bile acids (CDCA+GDCA) was significantly increased in the four experimental groups than in the normal group and the control group. The increase of CDCA was more significant than GDCA, suggesting that the increase of fecal bile acids, especially CDCA, may be one of the mechanisms by which RKM and the other three dietary fibers exerts a hypocholesterolemic effect

A Study on Hypolipidemic Effect of Hawthorn Flavonoids Extract

[Objectives] To research the hypolipidemic effect of hawthorn flavonoids extract. [Methods] The hawthorn flavonoids were extracted by percolation method. The SD rats were used for the experiment,and after the formation of high blood lipids in rats,the low,middle and high doses of hawthorn flavonoids extracts were used for intragastric administration. After 30 d,the changes of blood lipid in rats were detected. [Results] Hawthorn flavonoids significantly reduced total cholesterol and LDL,and adjusted triglycerides and HDL in the blood of SD rats. [Conclusions] Hawthorn flavonoids extract had significant hypolipidemic effect.

Evaluation of hypolipidemic activity of Brassica rapa and its mechanism analysis

Objective:This study was designed to evaluate the hypolipidemic activity of Brassica rapa and explore its mechanism by network pharmacology approach.Methods:The hypolipidemic activity of Brassica rapa aqueous extract(BRAE)was evaluated by bile salt-binding capacity and oleic acid-induced HepG2 steatosis cell model.The active compounds of Brassica rapa were collected from literature,and targets were predicted from SwissTargetPrediction and SEA Search Server platform.Cytoscape 3.7.2 software was used to construct“compound-target”network.Protein-protein interaction(PPI)network was constructed by String platform.Gene ontology(GO)and Kyoto encyclopedia of genes and genomes(KEGG)enrichment analyses based on DAVID database.Results:In vitro experiment showed that BRAE exhibited excellent bile salt-binding capacity,and the binding rates of sodium glycylcholate,sodium taurocholate and sodium deoxycholate were 36.01%,28.93%and 78.55%at 7 g.L-1,respectively.BRAE showed a significant hypolipidemic activity on steatosis cells,which can reduce the accumulation of lipid droplets and the levels of triglyceride(TG)and total cholesterol(TC)compared with the model group(P<0.05).21 active components of Brassica rapa and 682 potential targets were obtained,among which 55 targets were associated with hyperlipidemia.The“compound-target”network showed that 6-paradol,6-shogaol,benzyl-beta-D-glucopyranoside,benzyl-alpha-D-fructofuranoside and liquiritigenin were core components.PPI network and KEGG enrichment analysis found that Brassica rapa could treat hyperlipemia by regulated the core targets,such as VEGFA,IL6,EGFR and PPARG,and affected 36 signaling pathways(including starch and sucrose metabolism,galactose metabolism,insulin resistance,HIF-1,PI3K-Akt).Conclusion:This study showed that BRAE had excellent hypolipidemic activity in vitro,and preliminarily revealed the multi-component,multi-target,multi-path mechanism in the treatment of hyperlipidemia by network pharmacology approach,which provides a scientific foundation for further study.

Evaluation of hypoglycemic and hypolipidemic activities of aqueous extract of Cistus ladaniferus in streptozotocin-induced diabetic rats

Objective:To evaluate the effect of aqueous leaf extract of Cistus ladaniferus(C.ladaniferus) on glycemic and lipidemic status in diabetic rats.Methods:Overnight fasted rats were injected intraperitoneally with streptozotocin(45 mg/kg) to induce experimental diabetes.The aqueous extract of the leaves of C.ladaniferus was administered orally at the dose of 500 mg/kg body weight to diabetic rats for a period of 28 days.Hypoglycemic effect,body weight,oral glucose tolerance,change in lipid parameters,urea,creatinine,aspartate aminotransferase and alanine aminotransferase levels of diabetic rats treated with aqueous extract were evaluated in experimental animals.Results:Administration of 500 mg/kg of C.ladaniferus extract to diabetic rats for 28 days resulted in a significant reduction in the levels of blood glucose,alanine aminotransferase,aspartate aminotransferase,urea and creatinine.Furthermore,the extract of C.ladaniferus improved glucose tolerance in diabetic rats,and its antidiabetic effect was similar to the one obtained with glibenclamide.The hypolipidemic effect was demonstrated by an important decrease in plasma total cholesterol,triglycerides and low density lipoprotein-cholesterol levels.Conclusions:It is concluded that C.ladaniferus leaf extract showed an antidiabetic activity in experimental diabetes which was similar to the one obtained with glibenclamide.

Design and Manufacturing of Ultra-Hard Micro-Milling Tool

Based on the study of existing typical micro-milling tools and the actual demand for micro-milling tools, the P3 design principle and design flow for ultra-hard micro-milling tool were introduced to give basic guidance for the optimization of micro-milling tools. Then, according to the P3 design flow, the manufacturing process of polycrystalline diamond(PCD) micro-milling tool was proposed, and the PCD micro-milling tool with diameter of 0.5 mm was developed. Finally, the micro-milling test on the slot was carried out to study the milling performance of PCD micromilling tool.

Hypolipidemic Activity of Microwave-Dehydrated Mango (<i>Mangifera indica</i>L.) Powder in Mice Fed a Hypercholesterolemic Diet

The effect of dietary supplementation with mango (Mangifera indica L.) powder obtained by microwave dehydration was studied in normal and hypercholesterolemic mice. The phenolic profiles in methanolic extracts and antioxidant activities were determined using high-performance liquid chromatography and DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2'-azino-bis-3-ethyl-benzothiazoline-6-sulphonic acid) assays, respectively. The total phenolic content of microwave-dehydrated mango powder was 1451.7 ± 26.7 μggallic acid equivalents/g dry weight. The main phenolic compounds identified were gallic acid, epicatechin, ferulic acid, and catechin. The anti-oxidant activity was 14.6% higher in microwave-dehydrated mango powder than in conventional mango powder. Mice were fed a hypercholesterolemic diet (1 g cholesterol/100g over 7 days). The hypercholesterolemic mice whose diets were supplemented with microwave-dehydrated mango powder showed a significant decrease (P ≤ 0.05) in total serum cholesterol compared to the hypercholesterolemic mice and the mice fed with conventional dehydrated mango powder. We observed a significant increase (P ≤ 0.05) in HDL-c levels in the microwave-dehydrated mango powder group mice (12.4 ± 1.3 mmol/L) compared to the hypercholesterolemic group (8.6 ± 1.4 mmol/L) and the conventional-dehydrated mango powder group (10.9 ± 1.3 mmol/L). The mice provided with microwave-dehydrated mango powder had significantly lower (P ≤ 0.05) levels of serum LDL-c (36.0%) and total cholesterol (43.3%) compared to the mice in hypercholesterolemic group. Notably, the atherogenic index was 72% lower in the microwave-dehydrated mango powder group compared to the hypercholesterolemic group. These results suggest that the biocompounds, such as polyphenols and dietary fiber, found in mango pulp might improve the lipid profile in mice fed a hypercholesterolemic diet.

Development of a 2D Vibration Stage for Vibration-assisted Micro-milling

Vibration-assisted machining(VAM) has the advantages of extending tool life,reducing cutting force and improving the surface finish.Implementation of vibration assistance with high frequency and amplitude is still a challenge,especially for a micro-milling process.In this paper,a new 2D vibration stage for vibration-assisted micro-milling is developed.The kinematics of the milling process with vibration assistance is modeled,and the effects of vibration parameters on the periodic tool-workpiece separation(TWS) is analyzed.The structure of the vibration stage is designed with flexure hinges,and two piezoelectric actuators are used to drive the stage in two directions.An amplifier is integrated into the vibration stage,and the dynamics of the whole vibration system are identified and analyzed.Micro-milling experiments are conducted to determine the effects of vibration assistance on cutting force and surface quality.

南酸枣多糖的体外抗氧化、降血糖与降血脂作用

以南酸枣多糖体积分数40%乙醇沉淀组分CAP-40为研究对象,初步评价其体外抗氧化、降血糖与降血脂作用。分别利用高效液相凝胶渗透色谱及高效液相离子色谱测定CAP-40的分子量与单糖组成,同时测定其对DPPH·和ABTS+·的清除率,α-葡萄糖苷酶和α-淀粉酶的抑制率,甘氨胆酸钠和牛磺胆酸钠的结合率以及胰脂肪酶的抑制率。结果表明,CAP-40的洗脱曲线为单一对称峰,分子量约156206 Da,单糖主要由葡萄糖、半乳糖醛酸、半乳糖、阿拉伯糖、鼠李糖组成,摩尔百分比分别为40.8%、40.7%、9.3%、5.1%、2.0%。CAP-40浓度为1 mg/mL时,对DPPH·和ABTS^(+)·的清除率分别为(88.85±0.49)%和(87.13±1.63)%。浓度为16 mg/mL时,CAP-40对α-葡萄糖苷酶的抑制率为(71.28±2.34)%;在8 mg/mL处,对α-淀粉酶的抑制率为(72.29±4.85)%。此外,浓度为20 mg/mL时,CAP-40对胰脂肪酶的抑制率为(26.34±1.41)%;在5 mg/mL处,对甘氨胆酸钠和牛磺胆酸钠的结合率分别达到(31.87±4.53)%和(38.98±0.60)%。综上所述,南酸枣多糖CAP-40具有一定的体外抗氧化、降血糖与降血脂作用,为开发天然降糖、降脂功能食品提供理论依据,也为南酸枣资源的综合开发利用提供新的思路。