维药刺山柑果实的炮制方法研究

目的 研究刺山柑果实炮制方法并对其工艺进行优化。方法 分别建立UV和GC测定刺山柑果实中有效部位（总酚酸和总硫苷）及刺激性成分量的方法,并以其为指标筛选蒸、煮、烘及炒4种刺山柑果实的炮制方法,通过单因素试验和正交试验,选用渴求函数处理数据,对该炮制工艺进行优化。结果 刺山柑果实的最优炮制方法为炒法,最佳工艺为选用过40～50目筛的刺山柑果实粉末,炒制过程中药材温度为80 ℃,炒制时间为15 min。结论 炮制后的刺山柑果实在保证有效成分量的同时降低了其刺激性。     

Health benefits and possible risks of broccoli – An overview

Chemopreventive effects of broccoli, a highly valued vegetable, have been known for a long time. Several studies have demonstrated that broccoli might be beneficial by reducing the risk for the development of certain forms of cancer. These effects are generally attributed to glucosinolate-derived degradation products like isothiocyanates and indoles which are formed by the hydrolytic action of plant myrosinase and/or glucosidases deriving from the human microbial flora. However, recent in vitro and experimental animal studies indicate that broccoli, its extracts and the glucosinolate-derived degradation products might also have undesirable effects, especially genotoxic activities. However, the relevance of the genotoxic activities to human health is not known yet. This paper gives an overview on genotoxic, anti-genotoxic/chemopreventive, nutritive and antinutritive properties of broccoli, its ingredients and their degradation products. A qualitative comparison of the benefit and risk of broccoli consumption benefit-risk assessment shows that the benefit from intake in modest quantities and in processed form outweighs potential risks. For other preparations (fortified broccoli-based dietary supplements, diets with extraordinary high daily intake, consumption as a raw vegetable) further studies both for potential risks and beneficial effects are needed in order to assess the benefit and risk in the future.     

维药刺山柑果实的炮制方法研究

目的 研究刺山柑果实炮制方法并对其工艺进行优化.方法 分别建立UV和GC测定刺山柑果实中有效部位(总酚酸和总硫苷)及刺激性成分量的方法,并以其为指标筛选蒸、煮、烘及炒4种刺山柑果实的炮制方法,通过单因素试验和正交试验,选用渴求函数处理数据,对该炮制工艺进行优化.结果 刺山柑果实的最优炮制方法为炒法,最佳工艺为选用过40～50目筛的刺山柑果实粉末,炒制过程中药材温度为80℃,炒制时间为15 min.结论 炮制后的刺山柑果实在保证有效成分量的同时降低了其刺激性.     

Evolutionary limits ameliorate the negative impact of an invasive plant

Invasive species can quickly transform biological communities due to their high abundance and strong impacts on native species, in part because they can be released from the ecological forces that limit native populations. However, little is known about the long-term dynamics of invasions; do invaders maintain their dominant status over long time spans, or do new ecological and evolutionary forces eventually develop to limit their populations? Alliaria petiolata is a Eurasian species that aggressively invades North American forest understories, in part due to the production of toxic phytochemicals. Here we document a marked decline in its phytotoxin production and a consequent decline in their impact on three native species, across a 50+ year chronosequence of Alliaria petiolata invasion. Genetic evidence suggests that these patterns result from natural selection for decreased phytotoxin production rather than founder effects during introduction and spread. These patterns are consistent with the finding of slowing A. petiolata population growth and rebounding native species abundance across a separate chronosequence in Illinois, U.S. These results suggest that this invader is developing evolutionary limits in its introduced range and highlight the importance of understanding the long-term processes that shape species invasions and their impacts.     

Apoptosis as a Mechanism of the Cancer Chemopreventive Activity of Glucosinolates: a Review

Cruciferous vegetables are a rich source of glucosinolates that have established anti-carcinogenic activity.Naturally-occurring glucosinolates and their derivative isothiocyanates (ITCs), generated as a result of their enzymaticdegradation catalysed by myrosinase, have been linked to low cancer incidence in epidemiological studies, and inanimal models isothiocyanates suppressed chemically-induced tumorigenesis. The prospective effect of isothiocyanatesas anti-carcinogenic agent has been much explored as cytotoxic against wide array of cancer cell lines and beingexplored for the development of new anticancer drugs. However, the mechanisms of isothiocyanates in inducingapoptosis against tumor cell lines are still largely disregarded. A number of mechanisms are believed to be involvedin the glucosinolate-induced suppression of carcinogenesis, including the induction of apoptosis, biotransformation ofxenobiotic metabolism, oxidative stress, alteration of caspase activity, angiogenesis, histone deacytylation and cell cyclearrest. The molecular mechanisms through which isothiocyanates stimulate apoptosis in cancer cell lines have not sofar been clearly defined. This review summarizes the underlying mechanisms through which isothiocyanates modifythe apoptotic pathway leading to cell death.     

葡萄糖硫甙分析方法进展

葡萄糖硫甙是一类含硫、具亲水性,存在于十字花科植物中的植物次生代谢产物,近年来由于其具有抗癌性而广受关注。发展植物中硫甙分析技术是对其性质进行研究的前提,因此近年来有大量关于其分离和鉴定的技术的研究报道。本文对目前报道的葡萄糖硫甙测定新方法进行了总结。     

The synthesis of glucosinolates deuterium labelled in the glucose fragment

A facile synthesis is described for 2,3,4,6‐tetra‐O‐acetyl‐thio‐β‐D ‐[1‐²H,6‐²H₂]glucopyranose, which has been used to make an isotopically labelled desulphoglucosinolate, [1′‐²H,6′‐²H₂]desulfogluconasturtiin. This isotopically labelled building block can be employed to make any glucosinolate or desulfoglucosinolate for use as internal standards for MS based analytical methods. Copyright © 2006 John Wiley & Sons, Ltd.     

Black cabbage seed extract affects rat Cyp-mediated biotransformation: Organ and sex related differences

Brassicaceae are widely consumed in many parts of the world and their dietary intake has been associated with cancer risk reduction. Extracts and metabolites derived from cruciferous vegetables have thus gained popularity as potential cancer chemopreventive agents. We have previously found, unexpectly, that glucoraphanin, the most extensively present glucosinolate in these vegetables, is a potent mutagen bioactivating Phase-I enzyme inducer. In the present study, the influence of black cabbage seed extract, rich in glucoraphanin, was investigated on Phase-I enzymes in different organs of male or female rats. Oral seed extract injection at 120 or 240 mg/kg b.w. for one or four consecutive days, significantly affected various cytochrome P450 (CYP) –linked monooxygenases in a complex way being the lung the most responsive organ (in males, up to ∼2600% increase for CYP2B1/2 isoform and ∼96% loss for CYP1A1, CYP3A1/2). These findings indicate that the extract may strongly enhance and/or suppress rat xenobiotic biotransformation pathways and that caution should be paid to the possible influence on human metabolism. These data suggest an overall evaluation of the balance between beneficial vs. possible adverse effects for each agent, even if of natural origin, prior to routinely, preventive mass use.     

Coevolution between invasive and native plants driven by chemical competition and soil biota

Although reciprocal evolutionary responses between interacting species are a driving force behind the diversity of life, pairwise coevolution between plant competitors has received less attention than other species interactions and has been considered relatively less important in explaining ecological patterns. However, the success of species transported across biogeographic boundaries suggests a stronger role for evolutionary relationships in shaping plant interactions. Alliaria petiolata is a Eurasian species that has invaded North American forest understories, where it competes with native understory species in part by producing compounds that directly and indirectly slow the growth of competing species. Here I show that populations of A. petiolata from areas with a greater density of interspecific competitors invest more in a toxic allelochemical under common conditions. Furthermore, populations of a native competitor from areas with highly toxic invaders are more tolerant to competition from the invader, suggesting coevolutionary dynamics between the species. Field reciprocal transplants confirmed that native populations more tolerant to the invader had higher fitness when the invader was common, but these traits came at a cost when the invader was rare. Exotic species are often detrimentally dominant in their new range due to their evolutionary novelty; however, the development of new coevolutionary relationships may act to integrate exotic species into native communities.     

Determination of several families of phytochemicals in different pre-cooked convenience vegetables: effect of lifetime and cooking

Phytochemicals content, including several families such as phenolic acids, isoflavones, flavones, flavonols, isothiocyanates, and glucosinolates, was determined in pre-cooked convenience vegetables by ultra high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). It was observed that there is not a common behavior of the individual concentration of phytochemicals during the lifetime and cooking of the matrix, and compounds change their concentration without a specific trend. It was observed that neither lifetime nor cooking process have significant effects on the total content of phytochemicals except in broccoli, although some changes in the individual content of the target compounds were observed, suggesting that interconversion processes could be performed during the lifetime and/or cooking process of the product.