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1.
《Fitoterapia》2014
AimLycopene is a member of the carotenoid family and has strong anti-oxidant properties. Lycopene occurs in tomato-based food products primarily as an all-E isomer (80–97%),but its Z-isomers accounts for 79 to 88% of total lycopene in benign or malignant prostate tissues, while the specific biological functions of Z-isomers are still not clarified at present. This study was to examine the bioactive potency of Z-isomers on benign prostatic hyperplasia (BPH) in mice and to make a comparison of effective inhibition between Z-isomers and all-E isomer.MethodMice were divided into the Saline group, Vehicle control group and testosterone propionate induced BPH mice group (BPH model group, vehicle BPH model group, lycopene treated (5 mg/kg and 2.5 mg/kg), Z-isomers (57%) treated, Z-isomers (86%) treated, finasteride treated). The drugs were orally administered once a day consecutively for 30 days. The inhibitory effects on BPH of all-E lycopene and Z-isomers were evaluated by prostatic index, prostatic acid phosphatase (PAP), estradiol, testosterone and dihydrotestosterone (DHT) levels in serum and histopathology examination.ResultsCompared with the BPH model group, E/Z isomers exhibited significant differences in prostatic index, PAP, estradiol, testosterone and DHT levels in serum and similar histological aspects observed in the mice of the control group. The present research also shows that Z-isomers may be more potent inhibitors than all-E isomers in BPH treatment. 相似文献
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Antiperoxidative effects of lycopene during N-methyl-N'-nitro-N-nitrosoguanidine-induced gastric carcinogenesis 总被引:11,自引:0,他引:11
The effects of lycopene on blood oxidant-antioxidant balance during N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced gastric carcinogenesis in the presence of saturated sodium chloride (S-NaCl) as promoting agent were investigated. Enhanced lipid peroxidation in the blood of tumour-bearing animals was accompanied by significant decreases in the levels of reduced glutathione (GSH), ascorbic acid and vitamin E and the activities of glutathione peroxidase (GPx), glutathione-S-transferase (GST) and glutathione reductase (GR). Administration of lycopene significantly lowered the concentrations of lipid peroxides and enhanced antioxidant levels. We suggest that the modulatory effects of lycopene on the blood oxidant-antioxidant balance may be responsible for its chemopreventive potential. 相似文献
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The chemopreventive efficacy of lycopene on 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis was examined using lipid peroxidation, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR) as biomarkers of chemoprevention. Twenty four male Syrian hamsters were divided into four groups of six animals each. The right buccal pouches of the animals in group 1 were painted with a 0.5% solution of DMBA in liquid paraffin three times a week. The animals in group 2 were painted with DMBA as in group 1 and in addition received 2.5 mg/kg body weight lycopene orally three times a week on days alternate to DMBA application. Group 3 animals received lycopene as in group 2. Animals in group 4 received neither DMBA nor lycopene and served as control. The hamsters were killed after an experimental period of 14 weeks. Biochemical measurements were carried out in tumour and normal tissues. All hamsters painted with DMBA alone for 14 weeks developed well-differentiated squamous cell carcinomas. Diminished lipid peroxidation in the oral tumour tissue was accompanied by a significant increase in the levels of GSH, GPx, GST and GR. Administration of lycopene significantly suppressed DMBA-induced oral carcinogenesis as revealed by the absence of carcinomas. The results of the present study suggest that lycopene may exert its chemopreventive effects by modulating lipid peroxidation and enhancing the activities of the enzymes in the glutathione redox cycle. 相似文献
4.
Vaidhyanathan Bhuvaneswari Balaiya Velmurugan Seetharaman Balasenthil Chinnamanoor R. Ramachandran Siddavaram Nagini 《Fitoterapia》2001,72(8)
The chemopreventive efficacy of lycopene on 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis was examined using lipid peroxidation, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione S-transferase (GST) and glutathione reductase (GR) as biomarkers of chemoprevention. Twenty four male Syrian hamsters were divided into four groups of six animals each. The right buccal pouches of the animals in group 1 were painted with a 0.5% solution of DMBA in liquid paraffin three times a week. The animals in group 2 were painted with DMBA as in group 1 and in addition received 2.5 mg/kg body weight lycopene orally three times a week on days alternate to DMBA application. Group 3 animals received lycopene as in group 2. Animals in group 4 received neither DMBA nor lycopene and served as control. The hamsters were killed after an experimental period of 14 weeks. Biochemical measurements were carried out in tumour and normal tissues. All hamsters painted with DMBA alone for 14 weeks developed well-differentiated squamous cell carcinomas. Diminished lipid peroxidation in the oral tumour tissue was accompanied by a significant increase in the levels of GSH, GPx, GST and GR. Administration of lycopene significantly suppressed DMBA-induced oral carcinogenesis as revealed by the absence of carcinomas. The results of the present study suggest that lycopene may exert its chemopreventive effects by modulating lipid peroxidation and enhancing the activities of the enzymes in the glutathione redox cycle. 相似文献
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Leaf architecture, stand leaf area index and canopy light interception were studied in 13 poplar clones growing in a second rotation of a coppice plantation, to determine the role of leaf architectural attributes on canopy light-harvesting efficiency and to assess biomass investment in leaf support tissue. Stand leaf area index (L) varied from 2.89 to 6.99, but L was only weakly associated with canopy transmittance (TC). The weak relationship between TC and L was a result of a higher degree of foliage aggregation at larger values of L, leading to lower light-interception efficiency in stands with greater total leaf area. We observed a strong increase in leaf aggregation and a decrease in light-harvesting efficiency with decreasing mean leaf petiole length (PL) but not with leaf size, possibly because, in cordate or deltoid poplar leaves, most of the leaf area is located close to the petiole attachment to the lamina. Although PL was the key leaf characteristic of light-harvesting efficiency, clones with longer petioles had larger biomass investments in petioles, and there was a negative relationship between PL and L, demonstrating that enhanced light harvesting may lead to an overall decline in photosynthesizing leaf surface. Upper-canopy leaves were generally larger and had greater dry mass (MA) and nitrogen per unit area (NA) than lower-canopy leaves. Canopy plasticity in MA and NA was higher in clones with higher foliar biomass investment in midrib, and lower in clones with relatively longer petioles. These relationships suggest that there is a trade-off between photosynthetic plasticity and biomass investment in support, and also that high light-harvesting efficiency may be associated with lower photosynthetic plasticity. Our results demonstrate important clonal differences in leaf aggregation that are linked to leaf structure and biomass allocation patterns within the leaf. 相似文献
6.
Nitric oxide (NO) is an important signaling molecule involved in many physiological processes in plants. Nitric oxide generation and flavonoid accumulation are two early reactions of plants to ultraviolet-B (UV-B) irradiation. However, the source of UV-B-triggered NO generation and the role of NO in UV-B-induced flavonoid accumulation are not fully understood. In order to evaluate the origin of UV-B-triggered NO generation, we examined the responses of nitrate reductase (NR) activity and the expression levels of NIA1 and NIA2 genes in leaves of Betula pendula Roth (silver birch) seedlings to UV-B irradiation. The data show that UV-B irradiation stimulates NR activity and induces up-regulation of NIA1 but does not affect NIA2 expression during UV-B-triggered NO generation. Pretreatment of the leaves with NR inhibitors tungstate (TUN) and glutamine (Gln) abolishes not only UV-B-triggered NR activities but also UV-B-induced NO generation. Furthermore, application of TUN and Gln suppresses UV-B-induced flavonoid production in the leaves and the suppression of NR inhibitors on UV-B-induced flavonoid production can be reversed by NO via its donor sodium nitroprusside. Together, the data indicate that NIA1 in the leaves of silver birch seedlings is sensitive to UV-B and the UV-B-induced up-regulation of NIA1 may lead to enhancement of NR activity. Furthermore, our results demonstrate that NR is involved in UV-B-triggered NO generation and NR-mediated NO generation is essential for UV-B-induced flavonoid accumulation in silver birch leaves. 相似文献
7.
Jie Liu Ryo Ando Kuniyoshi Shimizu Koh Hashida Rei Makino Seiji Ohara Ryuichiro Kondo 《Journal of Wood Science》2008,54(1):68-75
In humans, steroid 5α-reductase is involved in the development of benign prostatic hyperplasia (BPH). We tested the steroid
5α-reductase inhibitory activity of the 70% acetone extract of woody plants. The tannin polymer prepared from the 70% acetone
extract showed the highest steroid 5α-reductase inhibitory activity. Furthermore, the steroid 5α-reductase inhibitory activity
of tannins was not affected by the addition of superoxide dismutase or catalase. It was concluded that the steroid 5α-reductase
inhibitory activity of condensed tannin was caused by binding to the steroid 5α-reductase, rather than from the peroxide/superoxide
produced by tannins. The tannins, prepared from tree barks, with potential for steroid 5α-reductase inhibitory activity might
be advantageous in therapy for steroid 5α-reductase diseases such as BPH or prostate cancer.
Part of this report was presented at the 54th Annual Meeting of the Japan Wood Research Society, Sapporo, August 2004 相似文献
8.
The current investigation has been conducted to investigate the influence of ginger on hepatic antioxidant enzymes system in ethanol treated rats. Ethanol significantly decreased the superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione content while an increase of malondialdehyde (MDA) levels were estimated in the hepatic tissue. This effect was reversed by a treatment with 1% dietary ginger for 4 weeks in rats by improved antioxidant status which suggest that treatment of ginger may have protective role against the ethanol induced hepatotoxicity. 相似文献
9.
Thomas Zumbrunnen Gianni B. PezzattiPatricia Menéndez Harald BugmannMatthias Bürgi Marco Conedera 《Forest Ecology and Management》2011,261(12):2188-2199
Understanding the factors driving past fire regimes is crucial in the context of global change as a basis for predicting future changes. In this study, we aimed to identify the impact of climate and human activities on fire occurrence in the most fire-prone regions of Switzerland. We considered forest fires, land use and meteorological data over the period 1904-2008 in the neighboring mountain cantons (states) of Valais and Ticino, which are characterized by distinct climatic regimes.The presence/absence of fire ignitions was analyzed using the Nesterov ignition index (as a proxy for fire weather), road density (for ignition sources), livestock density (for biomass removal), and change in forest area (for fire-prone abandoned agricultural areas).We found that fire weather played a key role in fire occurrence in both regions. Road and livestock densities had similar influences in the two cantons. However, while the increase in forest area was well correlated with fire occurrence in Ticino, no such correlation was evident in Valais, probably because land abandonment and forest cover change have been less extensive there. Our findings emphasize the non-linear nature of the relationships between fire occurrence and anthropogenic drivers, as we found thresholds above which road density was no longer correlated with fire occurrence. This implies that the projected future increase and spatial concentration of the human population may not result in a further increase in fire risk in intermediately to densely populated areas in both cantons.The driving factors behind fire activity differ slightly in the two cantons, in particular with increasing forest area enhancing fire occurrence in Ticino but not in Valais. These differences should be taken into account when assessing future fire risk, especially in Valais where the potential for an increase in the fire-prone area is still high. Fires are likely to become more frequent in a warmer climate, but future fire activity may develop differently in the two cantons. This should be taken into account when planning optimized fire prevention measures. This case study should help to better understand fire activity in highly populated regions where fire activity is still moderate but might markedly increase under a projected more fire-prone climate. 相似文献
10.
We argue that the conclusions drawn from the paper “The potential effect of climate change on the geographical distribution of insect pest species in the Swedish boreal forest”, published in the Scandinavian Journal of Forest Research were not erroneous as stated by a letter published in the same journal by Björklund et al. (2015. Erroneous conclusions about current geographical distribution and future expansion of forest insects in Northern Sweden: Comments on Hof and Svahlin (2015). Scand. J. Forest Res)”, but cautious. We regret possible underestimations caused by lack of occurrence records for some species for some areas. However, basing predictions of the impact of future climate change on the distribution of species on current range maps likely leads to grave overestimations of future range predictions since current range maps assume species are homogenously distributed throughout the landscape, which is often not the case. We argue that underestimating the distribution range of pest species rather than overestimating their distribution pinpoints areas that may need extra attention in future better, and therefore chose to be cautious rather than bold. We further like to stress that one should always be aware of possible insect outbreaks throughout the region, not only because predictions may underestimate the future distribution of species but also since the location and likelihood of insect pest outbreaks is not only determined by climatic factors. 相似文献
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Functional and structural characteristics of corticular photosynthesis of sun-exposed bark of olive tree (Olea europaea L.) were examined. Stomata are only sporadically present during stem primary growth. Light transmission through the phellem was age dependent, decreasing rapidly in stems older than five years of age. Light transmission was also low in pubescent 1-year-old stems. Light transmission was about 50% higher in wet phellem than in dry phellem. Photosynthetic capacity on a unit area basis (measured with an oxygen disc electrode at 27 degrees C and about 5% CO(2) on chlorophyllous tissue discs isolated from the stem) was higher in 1-, 20- and 30-year-old stems compared with 2-10-year-old stems. Low chlorophyll a/b ratio and light compensation points were recorded in olive stems with low phellem light transmission, in accordance with the shade acclimation hypothesis. The intrinsic photochemical efficiency of photosystem II of all stems, especially young stems, was less than that of the leaves. Our results show that olive tree bark possesses an efficient photosynthetic mechanism that may significantly contribute not only to the reduction in concentrations of CO(2) in the inner bark, but also to whole-tree carbon balance. 相似文献
14.
Steenkamp V 《Fitoterapia》2003,74(6):545-552
Phytomedicines are becoming more popular all over the world. Prostate cancer patients and those with benign prostatic hyperplasia are increasingly exploring the use of complementary alternative medicine especially due to the risk of mortality and long-term morbidity associated with surgical procedures. The incidences of prostate diseases are continually rising and the effect of phytomedicines already tested do provide relief, are well comparable with that of traditional forms of treatment. This paper reviews the phytomedicines used in Africa, Western countries and China as a treatment of benign prostatic hyperplasia, prostatitis and prostate cancer. Herbals which hold potential promise are mentioned, although much research is still required. 相似文献
15.
Nicholas Fisichelli Torsten Vor Christian Ammer 《European Journal of Forest Research》2014,133(4):587-596
Climate change includes not only shifts in mean conditions but also changes in the frequency and timing of extreme weather events. Tree seedlings, as the potential future overstory, are responding to the selective pressures of both mean and extreme conditions. We investigated how increases in mean temperature and the occurrence of late spring frosts affect emergence, development, growth, and survival of 13 native and non-native broadleaf and conifer tree species common in central Europe. Three temperature levels (ambient, +3, and +6 °C) and three spring frost treatments (control, late, and very late) were applied. Development responses of first-year seedlings to warmer temperatures were similar in direction and magnitude for broadleaf and conifer species. Stem size also increased with rising mean temperature for most species, though broadleaf species had maximal height advantage over conifer species in the warmest treatment. Sensitivity to frost differed sharply between the broadleaf and conifer groups. Broadleaf survival and stem length exhibited strong reductions due to frost events while conifer species only showed minor decreases in survival. Importantly, more rapid development and earlier leaf-out in response to warmer temperatures were associated with increased mortality from frost for broadleaf species but decreased mortality for conifer species. This research suggests that compositional shifts in the direction of species favored by increasing mean temperatures may be slowed by extreme events, and thus, the occurrence and impacts of such weather events must be acknowledged and incorporated into research and forest planning. 相似文献
16.
Samuli Helama Matti Vartiainen Taneli Kolström Jouko Meriläinen 《Wood Science and Technology》2010,44(2):335-351
X-ray microdensitometry was applied to a set of Scots pinewood (i.e. low extractive content). Earlywood and latewood properties
were determined as minimum and maximum densities of each tree ring and the potential influence of acetone-soluble extractives
(i.e. non-structural and secondary constituents of wood) was estimated using tree-ring statistics. The occurrence of extractives
in different portions of wood was determined using dendrochronological methods, by comparing the densities of unextracted
and extracted wood. It was not only found that unextracted samples exhibited inflated earlywood and latewood density values,
but the growth trends were also altered. Extractives flattened the inter-annual growth variability, both in earlywood and
latewood, and influenced the estimation of intra-annual radial growth variations. Characterizing the varying amount of extractives
is of inter-disciplinary importance. The results in this study describe their occurrence and show that the radial variations
in extractives could be highly detailed by simply using densitometry-based dendrochronology. 相似文献
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几种森林大型真菌纯培养菌种的RAPD及ITS分子标记鉴定 总被引:2,自引:0,他引:2
以采自野外的4对外生菌根菌和1对木腐菌的子实体及其各自的组织分离菌株作为研究材料,运用RAPD分子标记来分析组织分离菌株与子实体间的亲缘关系,通过PCR产物克隆测序比较二者的ITS碱基序列差异,最终对组织分离菌株是否为其纯培养菌种作出判定.RAPD分析结果表明,彩色豆马勃、白乳菇以及缘盖牛肝菌的子实体及其组织分离菌株分别在0.949、0.953以及0.969的Dice相似系数水平上聚为一类,而正红菇、香杯伞的子实体及其分离菌株仅在0.04和0.08的Dice相似系数水平上聚为一类.ITS序列测定分析结果显示,彩色豆马勃、白乳菇以及缘盖牛肝菌子实体与其各自组织分离菌株的ITS片段在长度和碱基序列上完全一致,而正红菇、香杯伞子实体与其各自分离菌株具有数量和长度均不同的ITS片段.RAPD分析结果与ITS分析结果相互支持,表明彩色豆马勃、白乳菇以及缘盖牛肝菌的组织分离菌株为其纯培养菌种,而正红菇、香杯伞的组织分离菌株并非其纯培养菌种,RAPD和ITS二种分子标记的结合运用可以更加高效准确地鉴定出外生菌根菌组织分离菌株是否为其纯培养菌种.ITS分析结果还提示正红菇、香杯伞子实体内可能存在多种伴生菌. 相似文献
20.
施肥对连栽地杉木针叶NR活力影响的研究 总被引:1,自引:0,他引:1
通过对9 个不同施肥处理的连栽地杉木针叶硝酸还原酶( N R) 活力进行了比较研究, 结果表明: N 肥对 N R 活力作用显著, 但与 P配施如 N P、 N P K、 M (氮磷钾加微量元素混施) 效果更好; K 肥对 N R 活力作用不大, 在没有配施 P肥的情况下, N K 肥反而使 N R 活力下降。在施 N P K 的基础上, 配合施入由多种微量元素组成的复合微肥, 对提高杉木多代林个体组织 N R 活力作用明显。 相似文献