Studies On The Purification And Pharmacological Effects Of Hypolipidemic Components From Momordica Charantia L.

Momordica charantia L.(MC) was a plant native in the eastern India. Modernstudies had shown that MC had many physiological benefits such as hypolipidemic,antidiabetic anti-viral, anti-tumor, antioxidant, etc. In this dissertation, thehypolipidemic effect of Momordica charantia L. extract based on fresh MC was studied.The peptide called MCP3-2was purified with hypolipidemic effect from the HepG2cellmodel of fatty liver in vitro, while the mechanisms were studied.Part I introduction. This part introduced the pharmacological effect of Momordicacharantia L. and its active ingredient, while described the hazards and treatment ofhyperlipidemia, as well as research of bioactive peptides. Finally it introduced theresearch methods and significances of hypolipidemic effect of Momordica charantia L.Part II. The second part was to investigate the effect of Momordica Charantia.L.crude extract on blood lipid of SD rat models with hyperlipidemia. The extract wasextracted with the water under experimental conditions. The extraction method usingammonium sulfate precipitation, while lyophilized to give a crude extract of MC. MaleSD rats were randomly divided into six groups with ten rats per group. Group fed withbasal diet served as a control group and other groups were fed the high-fat dietsincorporated with simvastatin or Momordica charantia.L. extract at dosages of50，100and200mg/kg, respectively. After12weeks，serum total cholesterol (TC), triglyceride(TG),high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol(LDL-C)were measured. Momordica Charantia.L polypeptide had no significant effecton body weight of rats with each dosage. The TG concentrations in serum weresignificantly decreased, especially the concentration of LDL-C were significantlydecreased, accompanied by an increase in HDL-C in rats at the dosages100mg/kg. Inaddition, Momordica Charantia.L. extract significantly reduced concentration of ALT,AST and FFA in liver protection. the crude extract of MC significantly reduced the number of fat vacuoles in the cytoplasm of hepatocytes, while had a therapeutic effecton fatty liver. In summary, these results suggest that the crude extract of MC couldsignificantly reduce blood lipid and liver lipid concentration and restore the morphologyand function of the liver tissue.Part III. Separation and purification of Momordica charantia.L. Momordicacharantia.L. was isolated preliminary by precipitation method with ammonium sulfateand dialytic technique, and then crude extract was obtained. Three compounds,MCP-1、MCP-2、MCP-3, were achieved through preliminary separation of crudeextractings using Sephadex G-75gel chromatography column. The active substances onblood lipid-depressing function, MCP-3, was screened out combining with theexperiments of in vitro fall hematic fat. Three compounds was achieved throughpreliminary separation of MCP-3using sephadex G-75gel chromatography column andThe active substances on blood lipid-depressing function, MCP3-2and MCP3-3, werescreened out. Analysis technique is used to determine the chemical composition ofcrude extractions and purified extractions from bitter melon. Chemical compositions ofbitter melon are as follows: moisture93.5%, ash1.92%, crude protein1.93%, crude fat0.89%, sugar1.71%. Protein content of every component was higher than95%afterpurification. Amino acid composition analysis was carried out and the results showedthat the highest content of amino acids in crude extractions from bitter melon wereglutamic acid, aspartic acid and leucine, they accounts for about33.66%of the totalcontent of amino acids. The highest contents in MCP-1were lysine, glutamic acid andasparagic acid, and they accounted for about31.68of the total amount of amino acids.The highest content in MCP-2were glutamic acid, aspartate acid and alanine acid,accounting for32.64%of the total content of amino acids. The highest contents inMCP-3were glutamic acid, aspartic acid and leucine, accounting for39.65%of the totalamount of amino acids. The highests content in MCP3-1were glutamic acid, leucineand cheese ammonia, accounting for26.13%of the total content of amino acids. Thehighests content in MCP3-2were aspartic acid, glutamic acid and lysine, accounting for 37.51%of the total content of amino acids. The highests content in MCP3-3wereglutamic acid, serine acid and lysine, accounting for33.58%of the total content ofamino acids. Compared with other active ingredients, MCP3-2and MCP3-3have moreserine and leucine, and this may be related to its cholesterol-lowering activity.Part IV. Effects of Momordica charantia L. protein on triglyceride metabolism inHepG2cells and the possible mechanisms. The lipid fraction in vitro experiments wasconducted with MCP3-2and MCP3-3. This part established the model of non-alcoholicfatty liver incubated with free fatty acid (palmitic acid: oleic acid,2:1, FFA) in HepG2cells. The FFA mixture was added to HepG2cells h after seeding. At the treatmentperiod, the groups were given with or without for24h afterward. During the last24h thecontrol (CON) and model groups (MO) were treated with culture medium only. Theother groups were received Momordica charantia L protein (including100,50,20,10μg/ml).At the end of the experimental period, the levels of intracellular triglyceridesand total protein were detected. MCP-treated groups (Dose of10，25,50and100μg/mg)showed a significant decrease in intracellular triglyceride levels as compared with theFFA group. After treating with FFAs for48h, the activity of CPT1A enzyme had nosignificant difference between FFA group and the CON group. MCP-treated groupsshowed a significant decrease as compared with the FFA group (P<0.01, P<0.01, P<0.01,P<0.05, respectively).Our results demonstrate that Momordica charantia L. proteinsubstantially reduces liver fat accumulation in rats fed with a HF diet. Due to theinvolvement of CPT1A enzyme in energy homeostasis, we speculate that bitter melonmay activate CPT1A enzyme in liver, leading to reductions in fat accumulation andhyperlipidemia in SD rats fed with a HF diet. Since lipids that accumulate in adiposetissue are largely derived from circulating TG and liver is a major target tissue for lipidand lipoprotein metabolism, bitter melon may be able to mobilize fat from adiposetissue by increasing fat catabolism in the liver.