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1.
抗肿瘤中药及其有效成分的作用研究现状   总被引:9,自引:2,他引:7  
中药是祖国医学理论中重要的组成部分,几千年来为保障我国人民和动物的机体健康做出了巨大的贡献。近年来,肿瘤的发病率不断增高,逐渐成为人类和动物健康的大敌。由于中药与化学合成药物相比有着取材方便、价格低廉和毒副作用小等优点,中药及其有效成分抗肿瘤的机理研究已成为当今医学研究的热点。中药及其有效成分防治肿瘤是通过多靶点、多途径、多环节来实现的,其抗肿瘤的作用机理主要包括调节机体免疫功能、抑制肿瘤血管生长、诱导肿瘤细胞凋亡、诱导肿瘤细胞分化、逆转肿瘤细胞多重耐药性、调节肿瘤细胞信号传导、抑制端粒酶活性和细胞毒作用等。中药及其有效成分必将为人类和动物肿瘤的治疗开辟新的途径。  相似文献   

2.
近年来国内外研究表明,白花蛇舌草中萜类、蒽醌类、黄酮类、多糖类、甾醇类等活性成分具有明显的抗肿瘤作用,其作用途径较为广泛,可通过抑制肿瘤细胞生长、诱导肿瘤细胞凋亡、调控细胞能量、增强机体免疫功能等发挥抗肿瘤作用。对中药白花蛇舌草有效成分的抗肿瘤作用机制研究进行综述,旨在为今后研究提供参考。  相似文献   

3.
肿瘤坏死因子诱导凋亡配体TRAIL作为肿瘤坏死因子超家族成员之一,其能和死亡受体相结合从而选择性诱导肿瘤细胞凋亡,却不会影响正常细胞,其正逐渐成为临床上新型抗肿瘤制剂。本文从肿瘤坏死因子诱导凋亡配体TRAIL何受体诱导凋亡机制入手,探讨其在临床方面的应用。  相似文献   

4.
1972年,英国的Kerr等首次提出细胞凋亡(apoptosis)的概念。之后,细胞凋亡便成为当前生命科学研究的热点。20世纪90年代以来,通过调控细胞凋亡来控制疾病日益受到人们的重视。近年来,随着多药耐药(MDR)的提出,给抗肿瘤药物临床应用提出新的难题。鉴于此,单味中药及其有效成分及复方制剂诱导肿瘤细胞凋亡的研究,正日益成为抗肿瘤药物的研究热点;当前,国外已将细胞凋亡作为评估抗肿瘤药物疗效的一个新指标。现就中药对细胞凋亡的影响(诱导或抑制),综述如下。1概述细胞凋亡又称细胞程序性死亡(PCD),是贯穿于机体整个生命活动过程的不同与坏死…  相似文献   

5.
本课题以人肝癌细胞HepG2为对象,研究了冬虫夏草醇提物辅助蜂胶的体外抗肿瘤作用。冬虫夏草和蜂胶都能通过诱导人肝癌HepG2细胞的凋亡实现其抗肿瘤作用。蜂胶与冬虫夏草联合使用增强了肿瘤细胞对作用药物的敏感性,提高了这两种药物对肿瘤细胞的杀伤率,能够起到协同抗肿瘤作用。本研究结果对冬虫夏草等珍稀草原野生植物资源作为辅助剂,增强蜂胶等名贵蜂产品的药理及保健作用的研究和探索产生深远的影响。  相似文献   

6.
研究“肿瘤消”的抗肿瘤活性和作用,为临床用药提供依据。通过 MTT 法检测“肿瘤消”对多种肿瘤细胞株和正常细胞存活率的影响;采用 Hoechst 染色法和 DNA 片段化分析对“肿瘤消”诱导 MDCC-MSBl 细胞凋亡的作用进行检测;Western blot 检测“肿瘤消”诱导 MDCC-MSBl 细胞凋亡相关蛋白因子表达情况。MTT 法检测结果显示,“肿瘤消”对 MDCC-MSBl、C6、SP2/0和 A549细胞的增殖具有明显抑制作用,对293A 细胞增殖无显著影响;Hoechst 染色和 DNA 片段化分析均证实“肿瘤消”能诱导 MDCC-MSBl细胞凋亡;Western blot 检测发现“肿瘤消”诱导 MDCC-MSBl 细胞凋亡与凋亡因子 caspase 3、caspase 8和caspase 9的活化有关。证实“肿瘤消”具有诱导肿瘤细胞凋亡的作用。  相似文献   

7.
天花粉蛋白抗肿瘤作用机理研究概况   总被引:6,自引:0,他引:6  
近年来,从天然动植物中寻找毒副作用小、安全有效的抗肿瘤药物已成为研究热点。天花粉蛋白是从葫芦科植物栝楼块根中分离纯化得到的单链核糖体失活蛋白,药理学研究发现其具有较强的抗肿瘤作用。文章从抑制肿瘤细胞增殖、诱导肿瘤细胞凋亡、抑制肿瘤细胞蛋白质的合成、对免疫系统的影响等方面对其抗肿瘤作用机理做了综述,为天花粉蛋白的进一步研究和临床应用提供理论依据。  相似文献   

8.
异荭草素是从植物中提取的含有黄酮类活性成分的化合物。研究表明,异荭草素具有多种药理作用,不仅可以抗氧化、抗炎、抗病毒,还具有良好的抗肿瘤活性。异荭草素可通过干扰肿瘤细胞增殖、诱导肿瘤细胞凋亡、调控活性氧水平、诱导肿瘤细胞自噬、阻碍肿瘤细胞浸润和转移等途径发挥抗肿瘤作用。现将异荭草素的抗肿瘤作用及其机制的相关研究进展进行综述。  相似文献   

9.
为了探讨莲草多糖和黄酮对诱导鸡MD肿瘤细胞凋亡的作用效果及其可能的作用机制,试验以鸡MDCC-MSB1细胞系为研究对象,通过观察细胞形态变化,分析细胞DNA片段化及半定量RT-PCR法检测莲草多糖和黄酮在安全浓度范围内对鸡MD肿瘤细胞凋亡及Bcl-2 mRNA表达的影响。结果表明,莲草多糖和黄酮能诱导MDCC-MSB1细胞凋亡,并降低MDCC-MSB1细胞内Bcl-2 mRNA的表达水平,致使细胞抗凋亡能力下降,进而发挥其药物作用。  相似文献   

10.
大蒜素诱导肿瘤细胞凋亡研究进展   总被引:4,自引:0,他引:4  
近年来许多体外研究表明大蒜素能够诱导包括白血病、肝癌、卵巢癌、胃癌等多种肿瘤细胞的凋亡,并取得了很好的效果,其诱导肿瘤细胞凋亡的途径可能是通过影响细胞生长周期、相关凋亡基因、caspase蛋白表达、细胞端粒酶活性等方式来实现的。大蒜素作为大蒜的主要活性成分,其抗癌效果备受人们的关注。大蒜素诱导肿瘤细胞凋亡是一个比较复杂的生物学过程,论文对大蒜等诱导肿瘤细胞凋亡的作用机制进行了综述。  相似文献   

11.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

12.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

13.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

14.
The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.  相似文献   

15.
16.
An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.  相似文献   

17.
Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein  相似文献   

18.
A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

19.
Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L3) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L3 developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.  相似文献   

20.
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