Review on mechanisms and structure-activity relationship of hypoglycemic effects of polysaccharides from natural resources

Diabetes mellitus(DM)is a common multifactorial disease,causing various complications,such as chronic metabolism.The current therapies for diabetes mellitus are commercial diabetic drugs that have different definite side effect.However,polysaccharides mainly extracted from natural resources,have advantages of safety,accessibility,and anti-diabetic potential.We have summarized recent research of natural polysaccharides with hypoglycemic activities,focusing on different pharmacological mechanisms in various cell and animal models.The relationships of structure-hypoglycemic effect are also discussed in detail.This review could provide a comprehensive perspective for better understanding on development and mechanism of natural polysaccharides against diabetes mellitus,which have been required by clinical studies yet.

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.

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

Hypoglycemic effects of black brick tea with fungal growth in hyperglycemic mice model

Dark tea(containing Eurotium cristatum)and black tea have hypoglycemic effects.The black brick tea with fungal growth is obtained from black tea by adding E.cristatum,followed by steaming,pressing,fungal growth,and drying.However,the hypoglycemic effects of black brick tea are still unexplored.Here,we used black brick tea with fungal growth and black tea as raw materials to study their hypoglycemic effects in a hyperglycemic mice model.Both these types of black tea could lower the content of blood glucose and increase the content of hepatic glycogen by upregulating the proteins and m RNA expression of phosphatidylinositol-4,5-bisphosphate3-kinase,glycogen synthase,protein kinase B and phosphoinositidedependent protein kinase-1 and downregulating the protein and m RNA expression of glycogen synthase kinase 3β.These regulatory steps were followed by high activities of glutathione peroxidase and superoxide dismutase and low content of malondialdehyde.These teas can promote blood glucose transport and absorption by upregulating the protein and m RNA expression of insulin receptor substrate-1 and glucose transporter-2 and stimulate glycolysis by upregulating the protein and m RNA expression of 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 2.Our study suggests that the black brick tea was more effective than the black tea in terms of hypoglycemic.

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.

The quality control and hypoglycemic effect of Cinnamomi Cortex aqueous extract

Cinnamomi Cortex was a material as medicinal and edible resources and it has been demonstrated that Cinnamomi Cortex aqueous extract(CCAE)possess hypoglycemic effect,but there were no active compounds identified as quality standard of CCAE to be used in the investigate of hypoglycemic activity.Hence,in this study,the quality standard and the hypoglycemic effect of CCAE were investigated.Cinnamaldehyde and coumarin as the quality control in CCAE were analyzed by high performance liquid chromatography(HPLC)method.The results showed that the average yield of extraction was 10.06%.The concentration of coumarin was linear with peak area ranging from 0.02–1.00μg/mL(r=0.9996,n=6)and that of cinnamaldehyde also demonstrated a good linear relationship with peak area in the range of 1.05–52.50μg/mL(r=0.9997,n=6).The average recovery rate of coumarin and cinnamaldehyde was 99.42%and 100.11%,respectively.The investigation of hypoglycemic effect revealed that CCAE could improve weight loss,lower liver and pancreas indices,improve organ damage caused by diabetes,and lower fasting blood glucose,glycosylated serum protein(GSP)and total cholesterol(TC)levels.The results showed that CCAE can reduce fasting blood glucose and blood lipid levels in diabetic mice.

Analysis of the Effect of Outpatient Nursing Intervention on Hypoglycemic Treatment Effect and Psychological Emotions of Diabetic Patients

Objective:To explore the effect of outpatient nursing interventions on the hypoglycemic treatment and psychological emotions of diabetic patients.Methods:148 patients who came to our hospital for outpatient treatment from February 2022 to October 2023 were selected and divided into a control group and an observation group,with 74 cases per group,according to the random number table method.The control group received routine nursing intervention,and the observation group received outpatient nursing intervention based on the control group.The two groups were observed for their effects of hypoglycemic treatment and psychological and emotional improvement before and after outpatient nursing intervention.Results:The health behavior scores of the control group were lower than that of the observation group;the post-intervention fasting blood glucose,2h postprandial blood glucose,anxiety self-rating scale(SAS),and the depression self-rating scale(SDS)of the control group were significantly higher than that of the observation group,and the difference was statistically significant(P<0.01).Conclusion:Outpatient nursing intervention encouraged patients to comply with healthy behaviors and helped control blood sugar levels.Patients’anxiety,depression,and other adverse psychological states were also improved hence the outpatient nursing intervention is worthy of further promotion.

Effects of Radix Puerariae, Radix Rehmanniae and Their Compatibility on Blood Glucose and Blood Lipids in Mice

[Objectives]To explore the effects of the compatibility of Radix Puerariae and Radix Rehmanniae on blood glucose and blood lipids in diabetic mouses.[Methods]Diabetic mouse model was established.The body weight and fasting blood glucose of mice were measured after 7 and 14 d of administration,and the biochemical indicators of blood lipids(TC,HDL-C,and LDL-C)were detected after 14 d of administration.[Results]Compared with the Radix Puerariae group and Radix Rehmanniae group,the compatibility group(1:2)had the best hypoglycemic effect(P<0.05),and TC and LDL-C in the compatibility group(2:1)significantly decreased(P<0.05),while HDL-C in the compatibility group(1:1)significantly increased(P<0.05).[Conclusions]Radix Puerariae,Radix Rehmanniae and their combination can reduce the blood glucose of diabetic mice.The compatibility group(1:2)had a significant hypoglycemic effect(P<0.05),and LDL-C in the compatibility group(2:1)significantly declined,while HDL-C in the compatibility group(1:1)rose significantly.

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.

Effects of resistant starchⅢon the serum lipids levels and gut microbiota of Kunming mice under high-fat diet

Resistant starch III(RS3),as a prebiotic,provides health benefits.This study aimed to investigate the role of RS3 in lowering serum lipids and regulating gut microbiota by administering Novelose 330 to Kunming(KM)mice.The results demonstrated that RS3 intervention significantly decreased body weight,food intake,levels of serum total cholesterol(TC),triglyceride(TG),low-density lipoprotein cholesterol(LDL-C),and liver fat.RS3 could remarkably improve the quality of the entire cecum,quality of the cecal wall,and wall surface area of mice;enhance the moisture content;and reduce the p H value.Moreover,the decrease in the liver TC content and the increase in the fecal TC content were related to RS3 intervention.The concentrations of total short-chain fatty acids(SCFAs)in the colon and individual levels of acetate,propionate,and butyrate increased with RS3 supplementation.An Illumina-based sequencing approach showed that RS3 notably increased the Bacteroides/Firmicutes ratio in the mice fed a high-fat diet.At the genus level,the relative abundance of Bacteroides,Ruminococcus,and Bifidobacterium and the number of main SCFA producers increased in the mice fed an RS3 diet.These findings provided insights into specific gut microbiota shifts to the hypolipidemic effect of RS3.

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.

Antioxidant and Hypoglycemic Ability of Ardisia gigantifolia Stapf Parts

[Objectives]To study the antioxidant and hypoglycemic effects of different parts of Ardisia gigantifolia Stapf.[Methods]The hydroxyl radical scavenging activity,DPPH radical scavenging activity and total antioxidant capacity of ABTS of 75%ethanol extract of A.gigantifolia Stapf and the petroleum ether,ethyl acetate,n-butanol,chloroform and aqueous extract were measured with Vc as positive control.At the same time,acarbose was used as reference substance to determine the inhibitory effect of each polar site onα-glucosidase.[Results]All parts of A.gigantifolia Stapf had antioxidant activity,among which ethyl acetate had the strongest antioxidant activity,and the scavenging rate of hydroxyl radical and DPPH radical was higher than that of positive control.The results showed that petroleum ether,ethyl acetate and chloroform had a good inhibitory effect onα-glucosidase(better than acarbose).[Conclusions]The ethyl acetate part of A.gigantifolia Stapf had the best antioxidant activity and inhibitory effect onα-glucosidase.It provides a basis for further research and development of A.gigantifolia Stapf.

Modulating Effects of Chlorogenic Acid on Lipids and Glucose Metabolism and Expression of Hepatic Peroxisome Proliferator-activated Receptor-α in Golden Hamsters Fed on High Fat Diet

Objective To examine the effects of chlorogenic acid （CGA） on lipid and glucose metabolism under a high dietary fat burden and to explore the possible role of peroxisome proliferator-activated receptor-α （PPAR-α） in these effects. Methods Twenty male golden hamsters were randomly divided into CGA treatment group （n=10, given peritoneal injection of CGA solution prepared with PBS, 80 mg CGA/kg body weight daily）, and control group （n=10, given PBS i.p. at the average volume of the treatment group）. Animals in both groups were given 15% high fat diet. Eight weeks after treatment with CGA, the level of biochemical parameters in fasting serum and tissues and the expression of hepatic mRNA and protein PPAR-α were determined. Results Eight weeks after treatment with CGA, the levels of fasting serum triglyceride （TG）, free fatty acid （FFA）, total cholesterol （TC）, low density lipoprotein cholesterol （LDL-C）, high density lipoprotein cholesterol （HDL-C）, glucose （FSG）, and insulin （FSI） were significantly lower in the GGA treatment group than in the control group. CGA also led to higher activity of hepatic lipase （HL） lower contents of TG and FFA in liver, and lower activity of lipoprotein lipase （LPL） in skeletal muscle. Furthermore, CGA significantly elevated significantly elevated the expression level of mRNA and protein expression in hepatic PPAR-α. Conclusion CGA can modify lipids and glucose metabolism, which may be attributed to PPAR-α facilitated lipid clearance in liver and improved insulin sensitivity.

Effect of black and white sesame on lowering blood lipids of rats with hyperlipidemia induced by high-fat diet

Sesamum indicum has various biological effects,and this study aimed to investigate its hypolipidemic effect.A hyperlipidemia rat model was established by feeding rats with high-fat diets in this study,then the hyperlipidemia rats were fed with different doses of black and white sesame seeds and black and white sesame kernels.The serum and liver biochemical indicators of the rats were determined,and liver pathology analysis was conducted to evaluate the hypolipidemic effect of sesame.The results showed that the blood lipid of SD(Sprague-Dawley)rats fed with high-fat diet for three weeks was higher than 200 mg/d L,indicating that the hyperlipidemia rat model was successfully established.At the same dose,the final body weights of the rats of white sesame seed and kernel groups were higher than those of the black sesame seed and kernel groups;and the weights of the black and white sesame seed groups were lower than those of the black and white sesame kernel groups.The liver indexes of the normal control group and the experimental groups were significantly lower than the model control group(P<0.05),indicating that black and white sesame seed and kernel could reduce the lipid accumulation on the liver.The malondialdehyde(MDA)values of the liver in the normal control group and the experimental groups were significantly lower than that in the model control group(P<0.05).The total antioxidant capacity(T-AOC),high density lipoprotein cholesterol(HDL-C),glutathione peroxidase(GSH-Px)and total superoxide dismutase(T-SOD)in the liver of each experimental group were significantly higher than those in the model control group(P<0.05).Based on the above results as well as pathological observation and analysis,we found that the black and white sesame seeds and kernels could improve fatty liver lesions and lipid metabolism disorder and could reduce lipid accumulation on the liver,thereby protecting the liver from damage and reducing the risk of fatty liver.Moreover,black and white sesame seeds,black and white sesame kernels can reduce the levels of total cholesterol(TC)and triglyceride(TG)in serum,and high dose of black sesame seeds(30%black sesame seeds)and low dose of black sesame kernels(10%black sesame kernels)were more beneficial for the recovery of hyperlipidemia and fatty liver.The above results indicated that black and white sesame has hypolipidemic effect.

Effects of Different Processed Products of Ilex hainanensis Merr on Rats with Hyperlipidemia

[Objectives] This study aimed to investigate the hypolipidemic effects of different processed products of Ilex hainanensis Merr to provide experimental basis for the research on the hypolipidemic mechanism of I. hainanensis Merr. [Methods] SD rats were fed high-fat diet to establish hyperlipidemia rat models. The hyperlipidemia rats were administered with different processed products of I. hainanensis Merr by gavage to investigate the preventive and therapeutic effects of the medicinal material. [Results] The levels of total cholesterol(TC), triglyceride(TG), low density lipoprotein cholesterol(LDL-C) in the rats fed high-fat diet were significantly higher than those in of the control group(P<0.01), indicating successful modeling. Among different processing methods, the hypolipidemic effects were in the order as baking=traditional processing=frying=microwaving>drying in shade. Among different baking times, the hypolipidemic effects ranked as 180 ℃>200 ℃=220 ℃. Among different baking times, the hypolipidemic effects ranked as 20 min=40 min>30 min. The hypolipidemic effects of processed product of I. hainanensis Merr with different amounts of active ingredients were different. [Conclusions] The processed products of I. hainanensis Merr all had hypolipidemic effects, but the effects were different. This study will provide a scientific basis for expanding the resources of I. hainanensis Merr.

Clinical effects of antidiabetic drugs on psoriasis:The perspective of evidence-based medicine

Psoriasis and diabetes shared common underlying pathophysiological mechanisms.Emerging data suggested that antidiabetic medications may improve the psoriasis severity in patients with diabetes mellitus.Several hypoglycemic agents including thiazolidinediones,glucagon-like peptide-1 receptor agonists,dipeptidyl peptidase-4 inhibitors,and biguanides have been reported to make a remarkable reduction in the Psoriasis Area and Severity Index score from baseline.This antipsoriatic effect could be mediated not only by the glucoselowering action of these agents but also via inhibition of keratinocyte over proliferation,increase expression of differentiation markers,suppression the immune inflammatory pathway,and blocking the calcium channels and mitogen-activated protein kinase signaling pathways.On the other hand,there was no significant increase in adverse reactions associated with the treatment of pioglitazone or metformin.However,previous studies often had the relatively short duration of the trials,and did not have enough power to assess recurrence of psoriasis.Potential bias in the study and missing data could undermine the reliability of the results.Therefore,the appropriately randomized controlled studies with large sample sizes and long-term durations in various psoriasis patients are warranted for further support.

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。

基于生物网络分析研究柑橘属果皮辅助预防2型糖尿病作用

目的:初步阐明柑橘属植物果皮辅助预防2型糖尿病的主成分与机制。方法:体外测定柑橘属植物果皮对α-糖苷酶的抑制活性,后通过网络药理学预测其可能的活性成分及其可能的作用机制,再用分子对接验证。结果:13批柑橘属植物果皮均对α-糖苷酶有一定的抑制作用,且在线性范围内呈现量效关系。网络药理学和分子对接技术预测,得到活性成分柚皮素、桔皮素、月桂酸可能通过氧化应激等途径来抑制高血糖,与炎症中的PI3KAkt、Ras、HIF-1信号通路有关,和血管相关的VEGF信号通路等有关。桔皮素为主成分。结论:柑橘属植物果皮对α-糖苷酶有抑制作用,可能对2型糖尿病有一定的辅助预防的作用。

荨麻多糖提取及其对HepG_(2)细胞的降糖作用研究

该文以荨麻为原材料,通过单因素试验和响应面试验优化半仿生提取荨麻多糖工艺。采用α-葡萄糖苷酶和α-淀粉酶抑制实验,测定荨麻多糖的降糖作用。通过构建胰岛素抵抗HepG_(2)细胞(insulin resistant HepG_(2),IR-HepG_(2))模型,测定甘油三酯(triglyceride,TG)、己糖激酶(hexokinase,HK)、丙酮酸激酶(pyruvate kinase,PK)、糖原含量来探讨荨麻多糖的降糖作用。结果表明,当pH_(1)3、pH_(2)8、料液比1∶16(g∶mL)、提取温度65℃、提取时间77 min时,荨麻多糖的得率为7.04%。α-葡萄糖苷酶和α-淀粉酶抑制实验表明,荨麻多糖可通过抑制α-葡萄糖苷酶和α-淀粉酶来表现降糖作用。细胞实验表明,荨麻多糖可通过影响IR-HepG_(2)细胞的葡萄糖消耗来减轻胰岛素抵抗;通过提高HK、PK含量,促进糖原合成,降低TG含量来调节糖脂代谢,从而发挥降糖作用。综上所述,荨麻多糖具有较强降糖活性,为将其应用于糖尿病患者辅助功能食品提供理论依据。

软枣猕猴桃黄酮降血糖作用研究

为探究软枣猕猴桃黄酮的降血糖作用,该研究对小鼠进行高脂高糖饲料喂养和链脲佐菌素注射,建立小鼠Ⅱ型糖尿病动物模型。将建模成功的小鼠随机分为6组,每组12只,即空白对照组、高脂高糖模型组、二甲双胍组、黄酮低剂量组、黄酮中剂量组和黄酮高剂量组。通过灌胃二甲双胍和不同剂量的软枣猕猴桃黄酮溶液,60 d后测定小鼠空腹血糖、血清胰岛素水平、肝脏葡萄糖激酶mRNA表达量以及葡萄糖激酶活性。结果表明,与高脂高糖模型组相比,黄酮中剂量组和高剂量组均可有效降低小鼠空腹血糖和胰岛素水平;3种软枣猕猴桃黄酮剂量组均可促进肝脏葡萄糖激酶mRNA表达量,并显著提高葡萄糖激酶活性。该研究为软枣猕猴桃黄酮作为调节糖代谢功能成分开发奠定理论基础。