Antioxidative effect of a chymotrypsin inhibitor from Momordica cochinchinensis (Cucurbitaceae) seeds in a primary rat hepatocyte culture.

The antioxidative activity of a chymotrypsin-specific potato type I inhibitor from Momordica cochinchinensis (MCoCI) (Cucurbitaceae) has been investigated using the primary rat hepatocyte system. tert-Butyl hydroperoxide (t-BHP) was used to induce oxidative stress. Pretreatment of hepatocytes with MCoCI for 24 h significantly reversed t-BHP-induced cell damage, and the associated glutathione depletion and lipid peroxidation. The activities of glutathione-S-transferase and superoxide dismutase were also increased. These results suggested that MCoCI possessed antioxidative activity which may account for some of the pharmacological effects of Momordica cochinchinensis seeds, the traditional Chinese medicine known as Mubiezhi, from which MCoCI was isolated.     

The stimulating effect of a cold, dark pretreatment on the etioplast/chloroplast transformation of angiosperms. I. The stimulating effect of cold predarkening on different stages of greening under white light

Schönbohm, E., Stute, U., Thienhaus, P. and Werner, U. 1988. The stimulating effect of a cold, dark pretreatment on the etioplast/chloroplast transformation of angiosperms I. The stimulating effect of cold predarkening on different stages of greening under white light. - Physiol. Plant. 72: 541–546.
The etioplast/chloroplast transformation in angiosperms is controlled by light; most of the processes are mediated by phytochrome. We have shown that in the primary leaves of etiolated seedlings of wheat ( Triticum aestivum L. cv. Kolibri), fire-bean ( Phaseolus multiflorus L. cv. Preisgewinner) and in the cotyledons of etiolated sun flower seedlings ( Helianthus annuus L. cv. macrocarpa) the chlorophyll accumulation in the phase after the end of the lag phase can be greatly stimulated by a cold predarkening period. This effect is not necessarily coupled with a red preirradiation. Furthermore the lag phase can be dramatically shortened by the cold, dark pretreatment, whereas the amount of photoconvertible protochlorophyll(ide) in the darkness remains unaffected by the cold, dark pretreatment. The stimulating effect of a cold, predarkening period on greening is fully reversible by a warm, dark phase that is placed between the cold period and the onset of the continuous white light phase. These findings cannot be generalized: We could demonstrate that in the tropical plant Momordica charantia greening under white light was not affected by different temperature pretreatments during predarkening. The stimulating effect of a cold, predarkening period on greening is assumed to have ecological relevance.     

赤(瓜包)亚族植物叶片中脉的比较解剖

本文对赤(瓜包)属(Thladiantha Bunge)、白兼果属(Baijiana A.M.Lu et J.Q.Li)和苦瓜属(Momordica L.)共11种植物叶片中脉进行了比较解剖学研究。除苦瓜属一种外,其余10种的叶片中脉解剖学资料均为首次报道。分析结果表明:叶片中脉维管束的数目以及排列方式具有分类学意义,而种间和种内维管束数目的减少,在一定程度上反映出植物迁移和演化的方向。     

Momordica charantia fruit juice stimulates glucose and amino acid uptakes in L6 myotubes

The fruit of Momordica charantia (family: Cucurbitacea) is used widely as a hypoglycaemic agent to treat diabetes mellitus (DM). The mechanism of the hypoglycaemic action of M. charantia in vitro is not fully understood. This study investigated the effect of M. charantia juice on either ³H-2-deoxyglucose or N-methyl-amino-a-isobutyric acid (¹⁴C-Me-AIB) uptake in L6 rat muscle cells cultured to the myotube stage. The fresh juice was centrifuged at 5000 rpm and the supernatant lyophilised. L6 myotubes were incubated with either insulin (100 nM), different concentrations (1–10 g ml^–1) of the juice or its chloroform extract or wortmannin (100 nM) over a period of 1–6 h. The results were expressed as pmol min^–1 (mg cell protein)^–1, n= 6–8 for each value. Basal ³H-deoxyglucose and ¹⁴C-Me-AIB uptakes by L6 myotubes after 1 h of incubation were (means ± S.E.M.) 32.14 ± 1.34 and 13.48 ± 1.86 pmol min^–1 (mg cell protein)^–1, respectively. Incubation of L6 myotubes with 100 nM insulin for 1 h resulted in significant (ANOVA, p < 0.05) increases in ³H-deoxyglucose and ¹⁴C-Me-AIB uptakes. Typically, ³H-deoxyglucose and ¹⁴C-Me-AIB uptakes in the presence of insulin were 58.57 ± 4.49 and 29.52 ± 3.41 pmol min^–1 (mg cell protein^–1), respectively. Incubation of L6 myotubes with three different concentrations (1, 5 and 10 g ml^–1) of either the lyophilised juice or its chloroform extract resulted in time-dependent increases in ³H-deoxy-D-glucose and ¹⁴C-Me-AIB uptakes, with maximal uptakes occurring at a concentration of 5 g ml^–1. Incubation of either insulin or the juice in the presence of wortmannin (a phosphatidylinositol 3-kinase inhibitor) resulted in a marked inhibition of ³H-deoxyglucose by L6 myotubes compared to the uptake obtained with either insulin or the juice alone. The results indicate that M. charantia fruit juice acts like insulin to exert its hypoglycaemic effect and moreover, it can stimulate amino acid uptake into skeletal muscle cells just like insulin. (Mol Cell Biochem 261: 99–104, 2004)     

苦瓜和瓜蒌体内皮质醇含量的测定

利用灵敏度高,专一性强的放射免疫法（ＲＩＡ）测定了苦瓜和瓜萎不同器官中皮质醇的含量。结果表明：苦瓜和瓜萎各器官均含有皮质醇,且含量在５０～４５０ｎｇ／ｇ．ＦＷ;顶芽中含量最高,其次是花器官;苦瓜和瓜篓雌花皮质醇含量明显高于雄花,且雌花在授粉后当天含量最高,说明皮质醇可能在植物的生长发育过程中起某种作用。     

苦瓜冻干粉对动物的降血糖作用及急性毒性

对药食同源植物苦瓜（Ｍｏｍｏｒｄｉｃａ ｃｈａｒａｎｔｉａ Ｌ．）的鲜汁冻干粉对动物的降血糖作用及急性毒性进行了药理实验,苦瓜冻干粉（生药量２０ｇ／ｋｇ和４０ｇ／ｋｇ）对药物性高血糖小鼠具有显著的降血糖作用,同时对正常小鼠血糖没有影响;苦瓜冻干粉的小鼠口服ＬＤ５０为生药量７０４．８ｇ／ｋｇ（９５％可信限生药量６１８．４～８０４ｇ／ｋｇ）,其产生降糖药效的剂量仅为其ＬＤ５０的１／３５～１／１７。     

Floral volatiles with colour cues from two cucurbitaceous plants causing attraction of Aulacophora foveicollis

Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) is an important phytophagous pest of two cucurbitaceous plants, Momordica cochinchinensis Spreng and Solena amplexicaulis (Lam.) Gandhi. The volatile organic compound profiles from flowers of M. cochinchinensis and S. amplexicaulis were identified and quantified by gas chromatography‐mass spectrometry (GC‐MS) and GC‐flame ionization detector (FID) analyses. Twenty nine and 28 compounds were identified in volatiles of M. cochinchinensis and S. amplexicaulis flowers, respectively. Methyl jasmonate and 3‐octanol were the predominant volatiles of M. cochinchinensis flowers, whereas 1‐octadecanol and 1‐hexanol were most found in the headspace of S. amplexicaulis flowers. Aulacophora foveicollis were more attracted by the flower volatiles of M. cochinchinensis than by those of S. amplexicaulis in a glass Y‐tube olfactometer. A mixture of 1‐heptanol, linalool oxide, 1‐octanol, and nonanal in the proportions present in the headspace of both flower types elicited attraction in the insect. From 25 cm distance, A. foveicollis displayed a preference for artificial flowers of 6.5 cm diameter of S. amplexicaulis flower colour (white) over M. cochinchinensis flower colour (white‐yellow). Finally, a synthetic blend (0.43 μg 1‐heptanol + 1.44 μg linalool oxide + 0.14 μg 1‐octanol + 1.77 μg nonanal dissolved in 25 μl methylene chloride) attracted more beetles when applied in a white artificial flower than when applied in a white‐yellow artificial flower from 40 cm distance. This finding may be helpful in the development of traps for pest management strategies.     

苦瓜的营养价值、化学成分以及药理作用研究进展

本文总结了半个多世纪来国内外学者对苦瓜的研究,为苦瓜进一步开发提供了借鉴。     

苦瓜MAP30基因的毕赤酵母表达载体构建及重组菌株的筛选

目的:从苦瓜中克隆MAP30全长基因,并将该基因连接至表达载体pPIC9中,建立酵母菌落PCR筛选方法。方法采用改良SDS法从苦瓜表皮中提取基因组DNA,设计特异性的引物,通过PCR技术扩增出全长861bp的MAP30基因。该基因经XhoⅠ和EcoRⅠ双酶切,连接至毕赤酵母表达载体pPIC9中。重组载体转化GS115菌株,运用菌落PCR鉴定重组菌株。结果:基因测序表明,该基因已成功插入酵母表达载体pPIC9α-factor分泌信号下游,同源性分析表明该基因与GeneBank(AF284811)的核苷酸同源性达99.9%,氨基酸同源性达100%。菌落PCR显示外源基因已整合入酵母GS115菌株中。结论:成功地克隆了MAP30全长基因,并构建了含MAP30基因的重组毕赤酵母表达载体,并获得了整合菌株,为下一步研究奠定了基础。     

Purification and Some Properties of Chitinase from Momordica charantia

Chitinase was purified from Momordica charantia L. by affinity chromatography. The purified enzyme showed single band on sodium dodecyl sulfate polyacrylamicle gel electrophoresis and the molecular weight was estimated as 35 kD. The enzyme was stable at temperatures up to 50℃ or less than 10 % loss of activity in 1 h. Its optimum temperature was about 45 ℃. Its suitable pH had a rather wide range from pH 4.4 to pH 6.8 and the optimum pH was about 6.2. The activity of the enzyme was similar in root and stem. In the lower leaves,the activity was higher than that of the upper.