苦瓜茎叶醋酸乙酯部位的化学成分研究

目的研究苦瓜茎叶醋酸乙酯部位的化学成分,为进一步开发利用苦瓜茎叶提供依据。方法采用反复硅胶柱色谱、反相ODS柱色谱、SephadexLH-20等柱色谱进行分离纯化,并根据波谱数据鉴定化合物的结构。结果分离得到3种苦瓜三萜,分别鉴定为苦瓜素I（1）、kuguacinN（2）、3,7．二羟基．23帜）-乙氧基-19．醛基．5,24-二烯醇（3）。结论化合物3为新化合物,命名为23．乙基苦瓜素I。     

Momordica charantia Ameliorates Insulin Resistance and Dyslipidemia with Altered Hepatic Glucose Production and Fatty Acid Synthesis and AMPK Phosphorylation in High‐fat‐fed Mice

Momordica charantia Linn. (Cucurbitaceae) fruit is commonly known as bitter melon. C57BL/6J mice were firstly divided randomly into two groups: the control (CON) group was fed with a low‐fat diet, whereas the experimental group was fed a 45% high‐fat (HF) diet for 8 weeks. Afterwards, the CON group was treated with vehicle, whereas the HF group was subdivided into five groups and still on HF diet and was given orally M. charantia extract (MCE) or rosiglitazone (Rosi) or not for 4 weeks. M. charantia decreased the weights of visceral fat and caused glucose lowering. AMP‐activated protein kinase (AMPK) is a major cellular regulator of lipid and glucose metabolism. MCE significantly increases the hepatic protein contents of AMPK phosphorylation by 126.2–297.3% and reduces expression of phosphenolpyruvate carboxykinase (PEPCK) and glucose production. Most importantly, MCE decreased expression of hepatic 11beta hydroxysteroid dehydroxygenase (11beta‐HSD1) gene, which contributed in attenuating diabetic state. Furthermore, MCE lowered serum triglycerides (TGs) by inhibition of hepatic fatty acid synthesis by dampening sterol response element binding protein 1c and fatty acid synthase mRNA leading to reduction in TGs synthesis. This study demonstrates M. charantia ameliorates diabetic and hyperlipidemic state in HF‐fed mice occurred by regulation of hepatic PEPCK, 11beta‐HSD1 and AMPK phosphorylation. Copyright © 2013 John Wiley & Sons, Ltd.     

Influence of Momordica charantia on oxidative stress-induced perturbations in brain monoamines and plasma corticosterone in albino rats

Objectives:

The objective of this study was to evaluate the antistress activity of Momordica charantia (MC) fruit extract on stress-induced changes in albino rats and also to explore attenuating effects of MC on in vitro lipid peroxidation in rat brain.

Materials and Methods:

In this study, Wistar albino rats (180–200 g) were used. Plasma corticosterone and monoamines—5-hydroxy tryptamine (5-HT), norepinephrine (NE), epinephrine (E) and dopamine (DA) in cortex, hypothalamus and hippocampus regions of brain were determined in animals under different stressful conditions. Ethanolic fruit extract of MC, at doses of 200 and 400 mg/kg, was used. The oxidative stress paradigms used in in vivo models were acute stress (AS) and chronic unpredictable stress (CUS). Panax quinquefolium (PQ) was used as a standard in in vivo models and ascorbic acid was used as a reference standard in the in vitro method.

Results:

Subjecting the animals to AS (immobilization for 150 min once only) resulted in significant elevation of plasma corticosterone levels and brain monoamine levels. Pretreatment with MC at doses of 200 and 400 mg/kg p.o. significantly countered AS-induced changes and a similar effect was exhibited by PQ at 100 mg/kg p.o. In the CUS regimen (different stressors for 7 days), plasma corticosterone levels were significantly elevated whereas the levels of 5-HT, NE, E, and DA were depleted significantly. Pretreatment with MC (200 and 400 mg/kg) attenuated the CUS-induced changes in the levels of above monoamines in cortex, hypothalamus, and hippocampus regions of brain and plasma corticosterone in a dose-dependent manner. Furthermore, MC extract (1000–5000 μg/mL) exhibited a significant quenching effect on in vitro lipid peroxidation indicating its strong antioxidant activity which was compared with ascorbic acid.

Conclusions:

This study reveals the antistress activity of MC as it significantly reverted the stress-induced changes, and the activity might be attributed to its antioxidant activity since stress is known to involve several oxidative mechanisms.     

The MAP30 protein from bitter gourd (Momordica charantia) seeds promotes apoptosis in liver cancer cells in vitro and in vivo

Human hepatocellular carcinoma Hep G2 cells and Hep G2-bearing mice were used as in vitro and in vivo models to assess the efficacy and safety of MAP30, a natural component from Momordica charantia, as an anticancer agent against liver cancer. Molecular studies disclosed the contribution of both caspase-8 regulated extrinsic and caspase-9 regulated intrinsic caspase cascades in MAP30-induced cell apoptosis. The antitumor potential was also effective in Hep G2-bearing nude mice. Since bitter gourd is a staple in many Asian countries, MAP30 would serve as a novel and relatively safe agent for prophylaxis and treatment of liver cancer.     

Momordica cochinchinensis Seed Extracts Suppress Migration and Invasion of Human Breast Cancer ZR-75-30 Cells Via Down-regulating MMP-2 and MMP-9

Objective: Metastases and invasion are the main reasons for oncotherapy failure. Momordica cochinchinensis(Mu Bie Zi in Chinese) had been used for a variety of purposes, and shown anti-cancer action. In this article, wefocused on effects on regulation of breast cancer cell ZR-75-30 metastases and invasion by extracts of Momordicacochinchinensis seeds (ESMCs). Methods: Effect of ESMCs on ZR-75-30 human breast cancer cells proliferationwere evaluated by MTT assay and on invasion and migration by wound-healing and matrigel invasion chamberassays. Expression and protease activity of two matrix metalloproteinases (MMPs), MMP-2 and MMP-9, wereanalyzed by Western blotting and gelatin zymography, respectively. Results: ESMC revealed strong growthinhibitory effects on ZR-75-30 cells, and effectively inhibited ZR-75-30 cell invasion in a dose-dependent manner.Western blot and gelatin zymography analysis showed that ESMC significantly inhibited the expression andsecretion of MMP-2 and MMP-9 in ZR-75-30 cells. Conclusions: ESMC has the potential to suppress the migrationand invasion of ZR-75-30 cancer cells, and it might prove to of interest in the development of novel inhibitorsfor breast cancer.     

木鳖子抗肿瘤有效作用部位筛选及作用机制探讨

目的:观察中药木鳖子不同提取部位体内体外的抗肿瘤作用,并考察其中抗肿瘤效果显著的木鳖子乙酸乙酯提取部位的抗肿瘤作用机制。方法:采用索氏提取技术将中药木鳖子按照溶剂极性顺序依次提取,得到不同成分,采用细胞增殖实验结合动物抗肿瘤模型方法进行药效评价,运用现代分子生物学技术阐明其中最优部位可能的抗肿瘤作用机制。结果:中药木鳖子乙酸乙酯提取部位在体外和体内实验中均可表现出明显的抑制肿瘤生长能力(P0.05),且对实验动物无明显的毒副作用,本研究首次发现木鳖子乙酸乙酯提取部位可影响表皮生长因子(EGFR)激酶活性(P0.05),并可明显抑制EGFR蛋白磷酸化表达(P0.05),可明显抑制丝裂原活化蛋白激酶家族(mitogen activated protein kinase,MAPKs)通路上重要节点蛋白细胞外信号调节激酶(extracellular regulated protein kinases,ERK1/2),氨基末端激酶(C-Jun N-terminal kinase,JNK)和丝裂原激活蛋白激酶p38的磷酸化水平(P0.05),且具有浓度依赖关系。结论:中药木鳖子乙酸乙酯提取部位可通过抑制EGFR蛋白及相关通路蛋白活性,在体内外实验中显著抑制肿瘤的生长。     

苦瓜茎叶的化学成分研究

目的 研究苦瓜茎叶的化学成分,为进一步开发利用苦瓜茎叶提供依据。方法 采用反复硅胶柱色谱、反相ODS柱色谱、Sephadex LH-20等柱色谱进行分离纯化,通过波谱数据鉴定化合物结构。结果 分离得到1种倍半萜和2种葫芦烷三萜,分别鉴定为催吐萝芙叶醇（1）、kuguacin J（2）、3,23(R)-二羟基-7-乙氧基-19-醛基-5,24-二烯醇（3）。结论 化合物1为首次从该植物中分离得到,化合物3为新化合物,命名为7-乙基苦瓜素Ⅰ。     

苦瓜中植物蛋白的研究概况

苦瓜是常见的蔬菜,也有着广泛的药用价值。其中蛋白类成见是极具特色的活性成分,总结了苦瓜中植物蛋白的研究概况。     

苦瓜蛋白酶抑制剂对苦瓜降糖多肽活性的保护作用

目的 探讨苦瓜蛋白酶抑制剂对苦瓜降糖多肽口服降糖活性的保护作用.方法 单次iv四氧嘧啶80mg/kg给药建立糖尿病小鼠模型.以降糖多肽(20、10、5 mg/kg)iv给药.于0.5、2、4、6、8 h尾静脉取血测定空腹血糖;测定在不同降糖多肽与蛋白酶抑制剂配伍剂量下,ig给药21 d后的空腹血糖值;以降糖作用显著的配伍比例,ig给药7、14、21 d和停止给药7 d后测定血糖.结果 降糖多肽于iv给药4 h后,高、中、低3个剂量均表现出显著降血糖效应(P<0.05、0.01);降糖多肽与抑制剂(300+300)、(100+100)、(100+50)、(100+25)mg/kg 4个配伍剂最组ig给药21 d后表现出显著降血糖效应,且以后两个剂量组ig给药的降血糖作用为更佳,停药7 d后给药组血糖值与模型组无显著差异.结论 苦瓜蛋白酶抑制剂在ig给药过程中能够使苦瓜降糖多肽免遭消化系统的蛋白水解酶破坏而起保护作用,维持其降血糖药效,该作用与两者间的配伍剂量有关.