不同氮水平对原产地和入侵地飞机草(Chromolaena odorata L.)DNA甲基化的影响

为探究原产地和入侵地飞机草DNA甲基化多态性的变化和氮营养水平对飞机草DNA甲基化多态性的影响,本文用水培法分别培养来自原产地墨西哥和入侵地西双版纳的飞机草(Chromolaena odorata L.),对两地飞机草进行了高氮(315 mg·L-1)、正常(中)氮(210 mg·L-1)和低氮(105 mg·L-1)3种氮水平处理,采用MSAP(甲基化敏感扩增多态性)技术测定试材的DNA甲基化水平。结果表明,无论是原产地还是入侵地的飞机草,在高氮和低氮处理条件下均发生了DNA甲基化水平和模式的改变;且入侵地飞机草DNA甲基化水平高于原产地飞机草,飞机草DNA甲基化水平都随着氮供应水平的升高而升高。本研究为从表观遗传角度揭示外来植物的入侵机制提供依据。

A comparative study on the antioxidant activity of methanolic leaf extracts of Ficus religiosa L,Chromolaena odorata(L.) King & Rabinson,Cynodon dactylon(L.) Pers.and Tridax procumbens L.

Objective:To compare the antioxidative effects of the methanolic leaf extracts of Ficus religiosa (F.religiosa),Chromolaena odorata(C.odorata),Cynodon dactylon(C.dactylon) and Trida,x procumbens(T.procumbens) as well as the contents of antioxidants in the extracts.Methods: Total phenol and total flavanoid contents were measured according to the standard procedures. The total antioxidant capacity was determined using the phosphomolybdenum method.Reducing power was determined by the potassium ferrieyanide reducing method.The free radical scavenging activity was measured by 2,2’-Diphenyl-l-picrylhydrazyl(DPPH) assay.Results: Quantitative phytochemical analysis of total phenol content showed that C.odorata had the highest content of phenolic compounds significantly followed by F.religiosa,T.procumbens and C.dactylon.As for the total flavanoids content,F.religiosa had the highest content,followed by C.odorata,T.procumbens and C.daxtylon.Study on the total antioxidant capacity revealed that F.religiosa,C.dactylon and C.odorata showed higher total antioxidant capacity.T.procumbens showed the lowest capacity.Meanwhile,T.procumbens and C.odorata have the highest reducing power activity followed by F.religiosa and C.dactylon.The results of DPPH radical scavenging activity indicated that T.procumbens induced the largest elevation as the concentration of its extract increased,followed by C.odorata and F.religiosa and C.dactylon.Conclusions:The present study demonstrates the antioxidative capacity of all the four plant species.Of all the plants,C.odorata,a perennial weed plant showed potentially a high antioxidant activity,with higher phenolic and flavonoids contents.The data suggest that C.odorata can be best utilized in developing bioantioxidants.

Anti-inflammatory effects of fatty acids isolated from Chromolaena odorata

Objective:To identify inhibitors of nitric oxide production and NF-κB activity from Chromolaena odorata（C.odorata）.Methods:The compounds isolated from the aerial parts of C.odorata by bioassay-guided fractionation were investigated for their inhibitory effects on the NO production and NF-κB activity in LPS-stimulated RAW264.7 cells.Results:Six fatty acids （S）-coriolic acid（1）,（S）-coriolic acid methyl ester（2）,（5）-15,16-didehydrocoriolic acid（3）,（S）- 15,16-didehydrocoriolic acid methyl ester（4）,linoleamide（5） and linolenamide（6） were isolated. All compounds inhibited the NO production at concentrations consistent with those required for NF-κB inhibition.Compound 2 was the most active with the IC50 values of 5.22 and 5.73μM. The addition of a double bond in the fatty chain decreased the inhibitory effects while the methyl esterification increased the activities.Conclusions:The fatty acid components in C.odorata with NF-κB inhibitory activity could explain the anti-inflammation property of this plant in traditional medicine.This study could also contribute to the better use of C.odorata for human health care.

Lead levels in Chromolaena odorata (Compositae) along rural and urban roads in Akwa Ibom State, Nigeria

Concentrations of lead(Pb) were determined in leaf samples of \%Chromolaena adorata\% from a rural road and an urban road in Akwa Ibom State of Nigeria in relation to vehicular traffic density. Mixed results were obtained wich no trend to indict automobile exhaust fumes. Lead was not detected in rain water from these areas and leaf lead levels seemed to relate more to soil lead concentrations. There was no significant difference in mean leaf lead levels between rural and urban leaf samples and between washed and unwashed leaf samples. It was suggested that the lack of concordance between vehicular traffic density and lead levels in leaves along the highways indicates either a low level use of tetraethyl leaded petrol or, a relatively low vehicular traffic density with lead from exhaust fumes not reaching a threshold to affect levels in plants or be detected in the atmosphere. Implications of concentrations obtained in leaves to consumers when compared with international standards were discussed.

Comparative Larvicidal Property of Leaf Extract of Chromolaena odorata L (Composidae) and Chlopyrifos (Organophosphorus Compound) on Simulium Larvae

To assess the phytochemical properties of Chromoleana odorata in the control of blackflies to help check the problem of environmental pollution from the use of chemical insecticides. Methods Dried pulverized leaves of Chromolaena odorata （100 g） were soaked in distilled water for 24 hours and the extract was filtered, marc pressed and evaporated over water bath. Stock solution of the dried mass （1 g） was concentrated by dissolving in 100 mL of water. Serial dilutions （100 mg/mL, 10 mg/mL, 1 mg/mL, 0.1 mg/mL, 0.01 mg/L, and 0.001 mg/mL） of both the extract and Chlopyrifos （organo phosphorus） were prepared and toxicity was tested on the larvae of Simulium species. Results The chemical compound recorded 100% larval mortality at all concentrations while the plant extract recorded 100% larval mortality in three （100, 10, and 1 mg/mL） of its diluent concentration. The percentage of larval mortality by chemical compound and plant extract was statistically insignificant （t = 0.2456, P〉0.05）, but the mortality rate was significant within 30 rain interval of exposure time （t= 3.756, P〈0.05）. The LCs0 of the plant extract was determined at about 0.001 mg/mL concentration. This showed that the plant extract had an appreciable larvicidal property close to that of the chemical compound. Conclusion This result indicates the usefulness of plant materials in the control of obnoxious insect vectors of mn. It also opens additional approach to the management of environment from toxic chemicals that are non-biodegradable and cause environmental imbalance in the ecosystem.

Isolation and Identification of Two Antibacterial Agents from <i>Chromolaena odorata</i>L. Active against Four Diarrheal Strains

Chromolaena odorata L (Asteraceae) is a bad invasive plant, found in the humid tropics and sub-tropics worldwide. It is used against dysentery, diarrhea, malaria, wound healing, headache and toothache in traditional medicine. In the present study, we investigated the antibacterial activities of different leaves extracts of Chromolaena odorata L. (cyclohexane, dichloromethane, ethyl acetate and butanol) against four clinical diarrheal strains (Klebsiella oxytoca, Salmonella enterica, Shigella sonnei and Vibrio cholera). We demonstrated that C. odorata leaves extracts show an antibacterial activity between 0.156 and 1.25 mg/mL. Bioassay-guided chromatography by bioautography with iodonitrotetrazolium-based colorimetric assay allowed the isolation and identification of two active compounds. After the combination of RP-HPLC, mass spectrometry analysis, 1D and 2D-NMR spectroscopy, we isolated and characterized two active molecules corresponding to 3’,4’,5,6,7-Pentamethoxyflavone (Sinensetin) and4’,5,6,7-Tetramethoxyflavone (Scutellareintetramethyl ether).

Effect of <i>Chromolaena odorata</i>Extracton Hematotoxicity and Spleen Histopathology Induced by <i>Salmonella typhi</i>in Wistar Rats

Salmonella typhi is a facultative intracellular pathogen that causes typhoid fever in humans. In the present study, the effect of Salmonella typhi infection on hematological indices and spleen histology in Wistar rats was investigated and was followed by an evaluation of the ameliorative potential of the methanol leaf extract of Chromolaena odorata (MLECO) compared with ciprofloxacin treatment. The animals were divided into six groups: group 1 was normal control, group 2 was infected with Salmonella typhi without treatment (negative control), groups 3, 4 and 5 were Salmonella typhi infected and treated with 100 mg/kg, 200 mg/kg and 400 mg/kg of the extract respectively and group 6 was also Salmonella typhi infected and treated with 500 mg/70kg of ciprofloxacin. The animals were inoculated with a single infectious dose of Salmonella typhi bacteria and thereafter, treated with the extract and ciprofloxacin for a period of seventeen days, after the animals were confirmed infected. The rats were humanely sacrificed and blood samples taken for haematological investigations, and the spleen harvested and processed for histological examinations. Chromolaena odorata administration reversed the adverse hematotoxicity and histopathological changes in the spleen induced by?Salmonella typhi?infection.

Attenuation of Salt-Loading Induced Cardiomegaly and Dyslipidemia in Wistar Rats by Aqueous Leaf Extract of <i>Chromolaena odorata</i>

The effect of aqueous extract of the leaves of Chromolaena odorata on body weight, organ sizes, lipid profiles and atherogenic indices was investigated in normal and sub-chronic salt-loaded rats. The normal and treatment control groups were fed 100% of commercial feed, while the test control, reference and test treatment groups received an 8% salt-loaded diet. The extract (at 100 and 200 mg/kg body weight) and moduretics (at 1 mg/kg body weight) were orally administered daily. The normal and test control groups orally received appropriate volumes of water. The extract was screened for bioactive components using gas chromatography-coupled-flame ionization detector. The main glycosides, saponins, allicins, alkaloids, benzoic acid derivatives, terpenes and lignans detected were arbutin, avenacin B-1 (and avenacin A-1), diallyl thiosulphinate, lupanine, ferulic acid (and vanillic acid), limonene and retusin, respectively. Compared to test control, the extract dose-dependently, significantly (P 0.05) lowered the heart size, plasma levels of triglyceride, total density lipoprotein, very low density lipoprotein, low density lipoprotein and non-high density lipoprotein cholesterol and atherogenic indices (cardiac risk ratio, atherogenic coefficient and atherogenic index of plasma). It also significantly increased plasma high density lipoprotein level. These results suggest a protective mechanism of the extract against hypertension induced cardiomegaly and dyslipidemia, thus suggesting that this may underlie its antihypertensive action.

Toxicological Assessment of <em>Chromoleana odorata</em>on <em>Clarias gariepinus</em>Juveniles

A study was carried out to investigate the toxicity effects of exposure of aqueous extract of Chromolaena odorata leave on gill/liver (histological) of juveniles catfish Clarias gariepinus. The leaves were harvested fresh, air dried for 7 days under ambient room temperature. 200 healthy juveniles catfish Clarias gariepinus specimen with average initial weight of 12.40 ± 2.46 cm (mean total length) and 8.26 ± 1.25 g (mean body weight) were exposed to aqueous extract of Chromolaena odorata leave at the concentration of 50, 100, 150, 200, 250 mg/l respectively. The physical reactions observed in the fish were: erratic swimming, gasping for air, loss of reflex, hyperactivities and skin discolorations which were more pronounced at high concentration and exposure time. The pH and dissolved oxygen significantly (P < 0.05) de-creased as the concentrations of C. odorata leaves extract increased. However, the values of Ammonia in the exposed media significantly (P < 0.05) in-creased as the concentrations of C. odorata leaves extract increased, compared to the control test medium. A high mortality rate was recorded, the histologi-cal conditions on gill and liver includes the deformation of gill tissue with overlapping of secondary lamella and disintegration of epithelial tissue lead-ing to diffuse mass of the gill lamella due to rapid cell lysis, gill clogging and gill structure disruption. Deformed primary and secondary lamella with dis-integrated gill filament, increasing vasculation, total fusion of gill filament lamella and filament length variation. Damage became severe with increasing concentration in C. odorata leaves to fish and exposure, while liver of Clarias gariepinus shows liver hepatocellular alteration and increase in hepatocyte disintegration, rupture blood cells in the entire cell with hemorrhage of the vessels and blur nature with severe breakage due to rupture.

Microscopic Features, Antioxidant and Antibacterial Capacities of Plants of the Congolese Cosmetopoeia, Raw Materials of Cosmeceuticals

Cosmeceuticals are the fastest growing products in the cosmetics field and represent a hybrid between cosmetics and drugs. The main benefits reported for cosmeceutical herbal extracts, used in skin care, include antioxidant and antimicrobial activities and the tyrosinase inhibiting effect. The aim of this study was to evaluate the antioxidant and antibacterial activities of extracts from Chromolaena odorata, Mitracarpus villosus, Senna alata, Tetradenia riparia, Cannabis sativa and Pterocarpus soyauxii used traditionally in the management of skin and skin annexes pathologies;additionally to determine their microscopical characteristics and their chromatographic fingerprints. Microscopic analyses showed the specific botanical microscopic characters for each plant that constitute the database useful for the identification and authentication of these botanicals. To the best of our knowledge, our work is the first to describe the microscopic histological characters of studied plants except for Cannabis sativa. The results of the TLC chromatographic analysis revealed the richness in phenolic compounds, terpenes in all extracts and Pterocarpus soyauxii contained coumarins. All extracts displayed high ABTS and DPPH radical-scavenging activities connected with their IC50 values at the concentration range of 1 - 125 μg/mL with Cannabis sativa and Pterocarpus soyauxii as the most active. All plant extracts exhibited antibacterial activity on Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus to varying degrees. Cannabis sativa exhibited strong effect on Staphylococcus aureus and Escherichia coli. Chromolaena odorata and Tetradenia riparia showed a marked effect on Escherichia coli. Although certain crude extracts from studied botanicals have been shown to be inactive, fractionation studies are needed to determine the active fractions. Obtained biological activities could be related to phytochemicals present in the organic extracts like phenolic compounds and terpenoids. The antioxidant and antibacterial activities of the studied species may have potential therapeutic interest and could justify their use in traditional medicine and local cosmeceutical resources, but further studies are needed, especially in vivo studies, to demonstrate the benefit of these extracts on skin and skin appendages care.

4种植物挥发油的化学成分分析及其对赤拟谷盗的生物活性

本试验采用水蒸气蒸馏法提取飞机草、假蒟、紫穗槐和毛麝香4种植物的挥发油,以气相色谱质谱联用(GC-MS)分析挥发油的化学成分组成,采用触杀和驱避活性测试评价以上植物挥发油对赤拟谷盗的生物活性。结果表明,从上述植物挥发油中共鉴定出100种成分,其中,飞机草轻油和飞机草重油主要含有肉豆蔻醚(34.32%,46.58%)和β-石竹烯(22.35%,17.98%),假蒟挥发油中主要含有β-胡椒烯(18.23%)和β-石竹烯(14.60%),紫穗槐挥发油主要含有α-蒎烯(26.31%),毛麝香挥发油主要含有γ-松油烯(24.90%)和环葑莰烯(16.59%)。此外,飞机草轻油和重油、假蒟、紫穗槐和毛麝香挥发油对赤拟谷盗具有一定的触杀活性,其24 h的LD 50分别为58.83、62.73、51.94、44.08μg/头和51.69μg/头,其中,紫穗槐挥发油的触杀活性最强。同时,上述植物挥发油对赤拟谷盗均具有一定的驱避活性,其相对关联度r_(i)分别为0.3406、0.6474、0.5612、0.5235和0.6572,其中,毛麝香挥发油的驱避活性最强(r_(i)=0.6572)。因此,紫穗槐和毛麝香挥发油在仓储害虫防治方面具有很好的研究价值和开发潜力。

Modeling vulnerability of protected areas to invasion by Chromolaena odorata under current and future climates

Invasive plant species and climate change are among the biggest threats to the ecological integrity of many ecosystems,including those of protected areas.Effective management of invasive plants requires information regarding their spatialdistributions Using maximum entropy,wemodeled habitat suitability for an invasive plant species Chromolaena odorata under current and future climatic conditions(HadGEM2-ESand MIROC5)in protected areas of four West African countries(Benin,Cote d'voire,Ghana,and Togo).Under current climatic conditions,approximately 73%of total land area within the protected areas was suitable for colonization by C.odorata.Under future climate projections,the total area of suitable habitats for this invasive plant was projected to decrease by 7-9%(HadGEM2-ES)and 12-14%(MIROC5).Country-specific patterns suggest that major protected areas in Cote d'Ivoire and Ghana will be more vulnerable to invasion by C.odorata than those in Benin and Togo under both current and future dimatic scenarios.To maintain normal ecosystem functioning and provisioning of ecosystem services within the protected areas studied here,locations that have been identified as most vulnerable to invasion by C.odorata should be accorded proportionately higher priority when formulating appropriate management strategies.

Anti-adipogenic effect of flavonoids from Chromolaena odorata leaves in 3T3-L1 adipocytes

Objective： The leaves of Chromolaena odorata, a highly invasive shrub found growing wild worldwide, are traditionally used for wound healing. Due to its high flavonoid contents, we aimed to find a new appli- cation for this plant. Preliminary tests using its ethanolic leaf extract showed that it could suppress the accumulation of lipids in adipocytes. We therefore studied the anti-adipogenic effect of several C. odorata leaf extracts and the relationship between molecular structure and bio-activity of its isolated flavonoid constituents using 3T3-LI preadipocytes/adipocytes as a model. Methods： Three leaf extracts and thirteen flavonoids isolated from C odorata were tested for their effect on lipid accumulation in 3T3-L1 adipocytes using AdipoRed reagent, with quercetin as the positive con- trol. The effects of active flavonoids on the adipocytes were confirmed by oil red O staining and visualized under a light microscope.Results： n-Hexane and ethyl acetate extracts of C odorata leaves displayed anti-adipogenic activity. The latter extract was the more potent one, especially at 40 μg/mL. Four flavonoids, pectolinarigenin, kaemp- feride, 4,2＇-dihydroxy-4＇,5＇,6＇-trimethoxychalcone and dillenetin, exhibited significant, concentration- dependent inhibitory effects on lipid accumulation in 3T3-L1 adipocytes. The most potent flavonoid obtained in this study was 4,2＇-dihydroxy-4＇,5＇,6＇-trimethoxychalcone, which caused 75% and 90% inhi- bition of cellular lipid accumulation at 30 and 50μmol/L, respectively. Both kaempferide and 4,2＇-dihy droxy-4＇,5＇,6＇-trimethoxychalcone were major constituents in the ethyl acetate extract of this plant.Conclusion： C odorata leaves contained several flavonoids with anti-adipogenic effects against lipid accu- mulation in 3T3-L1 adipocytes. The plant, normally considered a useless weed, may actually provide an abundant source of biologically active flavonoids.

飞机草和兰花菊三七光合作用对生长光强的适应

测定了干季不同光强下生长的飞机草和兰花菊三七叶片最大净光合速率 (Pmax)、荧光动力学参数、叶绿素含量和比叶重 (LMA) ,研究了两种植物适应光环境的策略 ,探讨了其与入侵性的关系。 1 0 0 %光强下 ,两种植物主要通过降低捕光色素复合体Ⅱ的含量减少光能吸收 ,提高Pmax增加光能利用维持叶片能量平衡 ,而它们的热耗散能力并不强 ,均显著低于其它光强下的值。 1 0 0 %光强下 ,提高类胡萝卜素含量是飞机草耗散过剩能量的有效策略 ,而兰花菊三七可能有其它耗散途径。4.5 %光强下仅飞机草能够存活 ,它通过降低LMA、维持很低的日间热耗散和较高的光合系统Ⅱ非环式电子传递效率适应了弱光环境。推测对强光环境较强的适应能力是入侵植物的共性之一 ,但这种能力强不一定入侵性大。

飞机草挥发油的化学组成及其对植物、真菌和昆虫生长的影响

飞机草挥发油对 5种植物幼苗生长有显著的抑制作用 ,受抑制的大小排序为黑麦草 >白菜 >萝卜 >四季豆 >水稻 .中等浓度 (80 0mg·L-1)飞机草挥发油对水稻稻瘟病菌的抑制作用最强 ,对长春花疫病菌的抑制作用次之 ,对香蕉枯萎病菌的抑制作用最弱 ;其抑菌率分别为 6 1.4 0 %、2 9.2 7%和 14 .4 4 % .10～ 2 0 μl·株 -1的飞机草挥发油对小菜蛾和黄曲条跳甲有显著的驱避产卵作用 .经GC/MS ,飞机草挥发油的化学成分主要是萜类化合物 ,如反式 石竹烯 (16 .5 8% )、δ 杜松烯 (15 .85 % )、α 可巴烯 (11.5 8% )、氧化石竹烯 (9.6 3% )、大根香叶烯 (4 .96 % )和α 艹律 草烯 (4 .32 % ) .

飞机草提取物对小菜蛾产卵驱避活性的研究

以干扰作用控制指数作为评价指标,测定了飞机草提取物和乙醇提取物的不同萃取物对小菜蛾产卵驱避作用活性。结果表明,飞机草乙醇提取物及其氯仿萃取物对小菜蛾具有较强的驱避作用,驱避效果达80%以上,对小菜蛾起驱避作用的活性成分主要存在于氯仿萃取物中。

入侵物种飞机草和紫茎泽兰的核型研究

报道了菊科(Asteraceae)原泽兰属(Eupatorium)2种植物的核型,飞机草(Chromolaenaodorata(L.)R.M.K ing&H.Robinson)2n=60,核型公式为2n=60=32 m+28 sm,核型属于“2A”型,紫茎泽兰(Ageratina adenophora(Sprengel)R.K ing&H.Robinson)2n=51,核型公式为2n=51=30 m+21 sm,核型属于“2B”型。飞机草的染色体数目变化较大,紫茎泽兰染色体数目较稳定。紫茎泽兰不能产生正常的花粉。飞机草有性生殖产生的种子发芽率低,紫茎泽兰无融合生殖产生的种子发芽率高,但2种植物入侵能力都很强,种子数量与2种植物的入侵性关系不大。

紫茎泽兰和飞机草的形态和光合特性对磷营养的响应

比较研究了紫茎泽兰和飞机草的生长、形态、生物量分配和光合特性对磷营养的可塑性反应,及与其入侵性的关系.结果表明,两种入侵植物对磷营养变化表现出很强的可塑性和适应性.低磷时,两种植物的根生物量比增大,利于养分吸收;高磷时,两种植物的比叶面积、最大净光合速率、光饱和点、单位面积的叶绿素和类胡萝卜素含量增大,同化面积和同化能力增强,利于碳积累.相比之下,紫茎泽兰对磷的适应性更强.随供磷量的增加,紫茎泽兰和飞机草的相对生长速率、总生物量、株高、分枝数、叶面积指数和最大净光合速率均显著增大,过量磷素对上述参数抑制较小,表明两种入侵植物偏好较高的磷环境,土壤磷含量升高有利于其入侵,并在高磷时,通过增大株高、分枝数和叶面积指数荫蔽排挤本地种.在本地种基本停止生长的干季,紫茎泽兰和飞机草仍维持较高的相对生长速率.这也与其入侵性密切相关.