Beneficial effects and mechanism of action of Momordica charantia juice in the treatment of streptozotocin-induced diabetes mellitus in rat

This study investigated the beneficial effects and mechanism of action of the juice of Momordica charantia in streptozotocin (STZ)-induced diabetes mellitus in rats. Diabetes mellitus was associated with significant (p < 0.01) time course reductions in body weight, plasma insulin and the number of insulin positive cells per islet and significant (p < 0.01) time course elevation in blood glucose and osmolarity and systolic blood pressure compared to age-matched healthy controls. Oral intake of M. charantia juice by STZ-induced diabetic rats partially reversed all the diabetes-induced effects measured. Daily oral administration of M. charantia juice to STZ-induced diabetic rates significantly (p < 0.01) reduced the Na⁺- and K⁺ -dependent absorptions of glucose by the brush border membrane vesicles of the jejunum compared to the responses obtained in STZ-induced diabetic rat. Either insulin (100 MM) or the fruit juice lyophilised extract (5 g · ml^–1) can stimulate ¹⁴C-D-glucose uptake in L6 myotubes. These effects were completely blocked by wortmannin, an inhibitor of phosphatidylinositol 3-kinase. High concentrations (10–200 g · ml^-1) of M. charantia juice extract inhibited ¹⁴C-D-glucose uptake in L6 myotubes compared to the control response. The effect of M. charantia treatment was also investigated on myelinated fibre abnormalities in the tibial nerve of STZ-induced diabetic and control rats. The results show that diabetes was associated with significant (p < 0.05) reduction in the mean cross-sectional myelinated nerve fibres, axonal area, myelin area and maximal fibre area compared to end controls. Treatment of STZ-induced diabetic rats with M. charantia juice normalised the structural abnormalities of peripheral nerves. The results indicate that M. charantia can exert marked beneficial effects in diabetic rats, and moreover, it can regulate glucose uptake into jejunum membrane brush border vesicles and stimulate glucose uptake into skeletal muscle cells similar to the response obtained with insulin. (Mol Cell Biochem 261: 63–70, 2004)     

Effect of Crop Rotation on Meloidogyne spp. and Pratylenchus spp. Populations in Strawberry Fields in Taiwan

Changes in population levels of Meloidogyne hapla, M. incognita, Pratylenchus coffeae, and P. penetrans were studied in 12 strawberry fields in the Dahu region of Taiwan. Ten potential rotation crops and two cultural practices were evaluated for their effect on nematode populations and influence on strawberry yield. Rotation with rice or taro and the cultural practice of flooding and bare fallowing for four months were found to reduce nematode soil populations to two or fewer nematodes per 100 ml soil. Average strawberry yields increased between 2.4% to 6.3% following taro compared to the bare fallow treatment. Corn suppressed M. incognita and M. hapla populations and resulted in an increased in strawberry yield compared to bare fallow. Other phytopathogens also present in these fields limited taro as the rotation choice for nematode management. Results of this research and economic analysis of the input requirements for various rotation crops, corn and bare fallow were recommended as the most appropriate rotation strategies for nematode management in strawberry in this region.     

苦瓜中苦瓜甾苷的提取工艺研究

本研究通过单因素实验和正交实验,采用HPTLC检测方法,以苦瓜甾苷浸提量为考察指标,对影响苦瓜甾苷提取效果的各因素进行了研究。结果表明各因素对苦瓜甾苷提取效果的影响程度从高到低依次为:乙醇浓度>固液比>浸提时间>浸提温度。确定了苦瓜甾苷的最佳提取工艺参数为乙醇浓度80%,浸提温度55℃,浸提时间5h,固液比1:10。     

HPLC-ELSD测定苦瓜皂甙的含量

本文用HPLCELSD法测定苦瓜中皂甙B的含量。色谱条件:色谱柱ZorbaxSBC18,4.6×150mm;检测器ELSD(EvaporativeLightScatteringDetector);柱温30℃;流动相:甲醇水(70:30);流速1.0mL/min,N2压力:2.0×105Pa。皂甙B的保留时间在为7.295min,在浓度为0.1058～5.290μg/μL之间有很好的线性关系(R2=0.9918)。平均加标回收率为100.27%(n=3),RSD=2.83%。实验结果表明此方法可以作为苦瓜皂甙的定量测定方法     

Influence of physico-chemical traits of bitter gourd, Momordica charantia L. on larval density and resistance to melon fruit fly, Bactrocera cucurbitae (Coquillett)

Abstract:  Melon fruit fly, Bactrocera cucurbitae (Coquillett) is one of the most important pests of bitter gourd, Momordica charantia L. Because of the difficulties associated with chemical control of this pest, it is important to identify the traits associated with resistance and their influence on pest multiplication. There were significant differences in test genotypes for fruit infestation and larval density/fruit. The wild accessions, IC 256185, IC 248256, IC 213311, IC 248282, IC 256110 and IC 248281 were identified as resistance sources to melon fruit fly. There was a significant and positive correlation ( r  = 0.96) between percentage fruit infestation and larval density/fruit. Percentage fruit infestation and larval density/fruit were positively correlated with depth of ribs, flesh thickness, fruit diameter and fruit length, and negatively associated with fruit toughness. Flesh thickness and fruit diameter explained 93.0% of the total variation for fruit fly infestation, and flesh thickness and fruit length explained 76.3% of the variation for larval density/fruit. Ascorbic acid, nitrogen, phosphorus, potassium, protein, reducing sugars, non-reducing sugars and total sugars were negatively correlated, while the moisture content showed a positive association with fruit fly infestation and larval density/fruit. Moisture, potassium and reducing sugar content explained 97.4% of the total variation in fruit infestation, while moisture, phosphorus, protein, reducing and total sugars explained 85.7% variation for larval density/fruit.     

苦瓜素类似物的分离纯化及其性质研究

本文采用硫酸铵分级沉淀、亲和层析、凝胶过滤等方法,从苦瓜(Momordicacharantia)种仁分得苦瓜素Ⅰ、Ⅱ。它们在SDS-聚丙烯酰胺凝胶电泳和等电聚焦电泳上均呈现单一区带,其分子量分别为26 000和28 000,等电点8.3,含糖量1.6％和2.0％。苦瓜素Ⅰ对小鼠腹腔给药LD_(50)值为2.54mg/kg,苦瓜素Ⅱ的致死剂量范围是9-14mg/kg。它们对无细胞体系蛋白合成都有强烈的抑制活性,其IC_(50)均小于0.1ng/mL。我们将苦瓜素Ⅰ、Ⅱ与文献报道的苦瓜抑制剂(Momordica chanantiainhibitor,MCI)和α、β-momorcharin进行了比较,发现它们分别与MCI和α-momorcharin相似。由于苦瓜素Ⅱ的毒性较低,更适合于制备免疫毒素。     

Fatty Acid n-Propyl and Ethyl Esters in the Volatile Oil from Dentcorn,Zea mays L. var. indentata,Silage

(+)-Marmelo Lactones A(VA) and B (VB) were synthesized from erythro-γ-methyl-l-glutamic acid (IA) and threo acid (IB), respectively. The absolute configurations of natural marmelo lactones were thus determined to be (2R, 4S) for (+)-marmelo lactone A and (2R, 4R) for ( – )-marmelo lactone B.     

Organogenesis of Lear Explants of Momordica grosvenori Swingle In Vitro

Leaves of Momordica grosvenori Swingle were used as experimatal material. Plantlets were obtained on MS medium supplemented with 6-BA 1 ppm and IBA 0.5 ppm. Histocytological observations on adventitious bud formation were carried out. After 1 week in culture, mesophyll cells obviously enlarged, cell divisions began in the mesophyll cells near the cut ends of explants, and meristemoids which consisted of small dark stained cells without chloroplasts were produced. Then meristemoids continued to proliferate and redifferentiated into many leaf-shaped bodies. Three weeks after cultivation, adiventitious buds were produced from meristemoids at surface layer of leaf-shaped body. The stem of plantlet was cut off when it reached 2 cm in height, and then was transferred onto MS basic medium supplemented with NAA 0.25–0.5 ppm for rooting. About 10 days after cultivation, vigorous root system was produced from the cut end of plantlets. It is possible that this technique of obtaining whole plants by leaf explant culture provides a method for the multiplication of the good individual plants of M. grosvenori.     

Morphological and plant hormonal changes during parasitization by Cuscuta japonica on Momordica charantia

The holostemparasitic plant Cuscuta parasitizes various plants and sucks nutrients from the host stem. We used Cuscuta japonica as the parasite and Momordica charantia as the host plant, and described their interaction. The parasitized Momordica stems started swelling as a hypertrophic response within 3 days after parasitization. Concurrently, the Cuscuta stem grew rapidly and developed bigger scale leaves than usual. Parasitized Momordica stems reduced photosynthetic activity. Histological observation revealed no programmed cell death but an increased number of vascular bundles in the Momordica stem, especially near the Cuscuta hyphae. The defensive response of Momordica mainly involved the SA pathway. Drastic increase of tZ- and DZ-type cytokinins in Momordica stems would play an important role for hypertrophy. Cuscuta had higher cZ endogenously and our results imply that each subtype of CK might play different roles during parasitization process. Comprehensive plant hormone analysis provides new insights into plant interaction studies.     

Descriptions and biological notes of Ctenoplectra bees from Southeast Asia and Taiwan (Hymenoptera: Apidae: Ctenoplectrini) with a new species from North Borneo

Six Ctenoplectra species are recorded from Southeast Asia and Taiwan. They are C. chalybea Smith, C. cornuta Gribodo, C. davidi Vachal, C. elsei Engel, C. sandakana sp. nov. and C. vagans Cockerell. Females of C. sandakana sp. nov. from North Borneo are similar to the mainland species C. chalybea , but differ mainly in the clypeal keel and the length of the antennal segments. The small blackish species, C. cornuta , is distributed in Myanmar, China and Taiwan and C. davidi is distributed in China, Russia and Taiwan; both species are seen at the flowers of Thladiantha . Ctenoplectra chalybea was collected from the Malay Peninsula, Myanmar, Taiwan and Vietnam. Ctenoplectra apicalis Smith and C. kelloggi Cockerell are allied to C. chalybea ; however, C. kelloggi is excluded from this study due to insufficient material. A key to the six known Ctenoplectra species is given. The large metallic species, C. chalybea and C. elsei , visit flowers of Momordica cochinchinensis (Lour.) Spreng. For the first time observations on the nest structures of C. chalybea and C. cornuta are presented. They choose remarkable places, such as artificial structures and buildings, for nest sites. The nest architecture prevents rain and direct sunlight from entering the nest. Bees used pre-existing holes or crevices in wood for nesting shelters and collected soil and appeared to mix it with some other substance to build nests. The cell lining materials and rubbing behaviors against the cell wall suggest that Ctenoplectra bees use floral oil mainly for cell lining materials.