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1.
Synedrella nodiflora (L.) Gaertn. (Asteraceae), is a weed with ethnomedicinal uses. To extend scientific information on this species, we evaluated the effects of different extraction procedures (maceration, Soxhlet, sonication and homogenizer-assisted extraction (HAE)) using methanol as solvent, on the chemical composition and biological potential. The chemical profiles of the extracts were identified using a chromatographic (UHPLC-HRMS) technique. The antioxidant and enzyme inhibitory activities of the studied extracts were determined. The extract obtained by Soxhlet technique showed a higher level of total phenolic (TPC) and flavonoid content (TFC) and was a superior source of antioxidant compounds. The macerated extract was the most potent inhibitor of cholinesterases and α-glucosidase, whereas the highest activity against tyrosinase was observed in the order of sonication > Soxhlet > HAE > maceration. A modest activity was observed against α-amylase for all the extracts. Multivariate analysis showed that the bioactive compounds recovery and the biological activities of S. nodiflora were mostly dependent on the nature of the extraction technique used. In conclusion, S. nodiflora extracts showed good biological potential and data massed from this study could serve as a scientific baseline for further investigation in order to exploit its potential for designing novel bio-products with therapeutic applications.  相似文献   

2.
Ageratum conyzoides L. (billy goat weed; Asteraceae) is an annual invasive weed native of tropical America and has now naturalized worldwide, particularly in Southeast Asia. The present study investigated the nature and potential of root-mediated allelopathic interference of A. conyzoides against rice (Oryza sativa). Root and shoot length and biomass accumulation of rice were significantly reduced (by 18–30%) when grown in the rhizosphere soil of the weed indicating the release of putative allelochemicals from the weed into the soil. The growth of rice was also progressively reduced in the soil amended with increasing amounts of root residues (5, 10 and 20 g kg−1 soil) of A. conyzoides. The addition of activated charcoal, an inert material with high affinity for organic biomolecules, partly ameliorated the negative effects of root residues amended in the soil. Further, there was no negative effect on the availability of soil nutrients in the root-amended soils. These were rather nutrient rich with greater electrical conductivity, and higher amount of organic matter, thus indicating no role in observed growth reduction. The reduction in allelopathic effects of root residue upon charcoal addition further indicated that putative phytotoxins released from the weed roots are water-soluble phenolic compounds. A significant amount of water-soluble phenolics were present in rhizosphere (∼6-times higher) and root-amended soils (∼5–10-fold higher) and their content was reduced (to ∼3.6–7.0-fold higher) when charcoal was added. The observed growth reduction in Ageratum rhizospheric or root-amended soils was concomitant with the amount of phenolic compounds. Upon HPLC analyses, these were identified as p-coumaric acid, gallic acid, ferulic acid, p-hydroxybenzoic acid and anisic acid. Under laboratory conditions, these phenolic acids reduced the root length and seedling weight of rice individually as well as in equimolar mixture, though no synergistic effect was noticed. The study concludes that root exudates and residues of A. conyzoides suppress the growth of rice by releasing phenolic allelochemicals into the soil rhizosphere and not through alteration of soil nutrients, and allelopathy plays a significant role in root-mediated negative interference of A. conyzoides.  相似文献   

3.
The present study investigated the allelopathic interference of leaf debris of Ageratum conyzoides (billy goat weed; Asteraceae)—a weed of cultivated land—against rice (Oryza sativa). Seedling length and dry weight of rice were significantly reduced (16–20%) in soil from A. conyzoides infested fields compared to the soil from an area devoid of the weed. It indicated the presence of certain phytotoxins in the A. conyzoides infested soil. To explore the possible contribution of the weed in releasing these phytotoxins, growth studies involving leaf debris extracts and amended soils (prepared by incorporating leaf debris—5, 10, 20 g kg−1 soil, w/w, or its extracts—0.5%, 1.0% and 2.0%, v/v) were conducted. The growth of rice was severely inhibited in A. conyzoides leaf debris- and debris extract-amended soils compared to unamended control soil. A significant amount of water-soluble phenolics, the potent phytotoxins, was found in the A. conyzoides infested soil, leaf debris, and debris-amended soils. These phenolics were identified as gallic acid, coumalic acid, protocatechuic acid, catechin and p-hydroxybenzoic acid. Among these, protocatechuic acid was in the maximum amount (35.72%) followed by coumalic acid (33.49%) and these two accounted for >69% of total phenolic compounds. Further, there was a significant increase in the available nutrient content in soil amended with A. conyzoides leaf debris thus ruling out the possibility of any resource depletion upon residue incorporation and their negative role in causing growth reduction. Based on the observations, the present study concludes that leaf debris of A. conyzoides deleteriously affects the early growth of rice by releasing water-soluble phenolic acids into the soil environment and not through soil nutrient depletion.  相似文献   

4.
The direct negative effects of invasive plant species on agriculture and biodiversity are well known, but their indirect effects on human health, and particularly their interactions with disease-transmitting vectors, remains poorly explored. This study sought to investigate the impact of the invasive Neotropical weed Parthenium hysterophorus and its toxins on the survival and energy reserves of the malaria vector Anopheles gambiae. In this study, we compared the fitness of An. gambiae fed on three differentially attractive mosquito host plants and their major toxins; the highly aggressive invasive Neotropical weed Parthenium hysterophorus (Asteraceae) in East Africa and two other adapted weeds, Ricinus communis (Euphorbiaceae) and Bidens pilosa (Asteraceae). Our results showed that female An. gambiae fitness varied with host plants as females survived better and accumulated substantial energy reserves when fed on P. hysterophorus and R. communis compared to B. pilosa. Females tolerated parthenin and 1-phenylhepta-1, 3, 5-triyne, the toxins produced by P. hysterophorus and B. pilosa, respectively, but not ricinine produced by R. communis. Given that invasive plants like P. hysterophorus can suppress or even replace less competitive species that might be less suitable host-plants for arthropod disease vectors, the spread of invasive plants could lead to higher disease transmission. Parthenium hysterophorus represents a possible indirect effect of invasive plants on human health, which underpins the need to include an additional health dimension in risk-analysis modelling for invasive plants.  相似文献   

5.
The methanol extracts from five different plant families (Asteraceae, Euphorbiaceae, Melastomataceae, Rubiaceae, and Solanaceae) collected at Regional Natural Park Ucumarí (Colombia), were screened for their acetylcholinesterase inhibitory activity through the modified Ellman's spectrophotometric method. The best inhibitory activities on this study were shown by the extracts of Solanum leucocarpum Dunal (IC50 = 204.59 mg/l) and Witheringia coccoloboides (Damm) (IC50 = 220.68 mg/l), both plants belonging to the Solanaceae family.  相似文献   

6.
7.
Stems and roots of Salacia genus plants have been used as a specific remedy for early-stage diabetes, and one of the four sulphonium sulphates, salacinol is the compound responsible for the anti-diabetic activity. Salacia is prone to microbial contamination and insect infestation; hence, methods to estimate the microbial load in such plants will enhance its nutritional value. This paper highlights the novel use of Soleris® to quantify microbes of all types, namely bacteria, yeasts, molds, and coliforms in herbal extracts. The microbial analysis results obtained with Soleris® test vial have been compared with the conventional method, and the results indicate that Soleris® is equally efficient as the conventional method and in fact displays several advantages over the traditional method. The Soleris® method is a real time monitoring system that is highly sensitive, user-friendly, and environmentally friendly since it generates very little biomedical waste and saves a large amount of time. The data presented here demonstrate that for highly contaminated samples, results are available within 24 h. For yeasts and molds, the Soleris® method produces results in 48 h, thus offering considerable time savings compared to other commonly used methods.Key words: Salacia, salacinol, microbial load, bacteria, yeasts, herbals  相似文献   

8.
Ribulose 1,5-diphosphate carboxylase was detected in extracts of germinating castor bean (Ricinus communis var. Hale) endosperms. This is the first report of this enzyme in a nonphotosynthetic (no chlorophyll) plant tissue. Radioactive 3-phosphoglyceric acid has been identified as the principle product resulting from the enzymatic condensation of 14C-bicarbonate and ribulose-1,5-diP in endosperm extracts. The Km values of bicarbonate and ribulose-1,5-diP for the endosperm carboxylase are 1.14 × 10−2m and 7.5 × 10−5m, respectively. The carboxylase activity peaks at 4 days in endosperms of castor beans germinated in the dark. The specific activity of the carboxylase at this stage of germination is 4.3 μmoles of 3-phosphoglycerate formed/mg protein·hr. The presence of ribulose-1,5-diP carboxylase and other enzymes of the reductive pentose phosphate pathway show the potential of this pathway in castor bean endosperms.  相似文献   

9.
Release of Malate from Epidermal Strips during Stomatal Closure   总被引:13,自引:4,他引:9       下载免费PDF全文
Isolated epidermal strips of Vicia faba and Commelina communis release malate into their bathing medium when stomata close. This release was largest (about 0.6 of the initial malate content) when epidermal strips of C. communis were floated on 10−5 M (±)-abscisic acid.  相似文献   

10.
In this study we used differentiated adult human upcyte® cells for the in vitro generation of liver organoids. Upcyte® cells are genetically engineered cell strains derived from primary human cells by lenti-viral transduction of genes or gene combinations inducing transient proliferation capacity (upcyte® process). Proliferating upcyte® cells undergo a finite number of cell divisions, i.e., 20 to 40 population doublings, but upon withdrawal of proliferation stimulating factors, they regain most of the cell specific characteristics of primary cells. When a defined mixture of differentiated human upcyte® cells (hepatocytes, liver sinusoidal endothelial cells (LSECs) and mesenchymal stem cells (MSCs)) was cultured in vitro on a thick layer of Matrigel™, they self-organized to form liver organoid-like structures within 24 hours. When further cultured for 10 days in a bioreactor, these liver organoids show typical functional characteristics of liver parenchyma including activity of cytochromes P450, CYP3A4, CYP2B6 and CYP2C9 as well as mRNA expression of several marker genes and other enzymes. In summary, we hereby describe that 3D functional hepatic structures composed of primary human cell strains can be generated in vitro. They can be cultured for a prolonged period of time and are potentially useful ex vivo models to study liver functions.  相似文献   

11.
12.
The responses of some Lepidoptera to labiate herb and white clover extracts   总被引:2,自引:0,他引:2  
Herbs have been traditionally used as intercrops with crop plants on the assumption that their odour repels pest species. Alcohol extracts and essential oils of labiate herbs were tested in the laboratory for deterrent/repellent responses to ovipositing Plutella xylostella (L.) and feeding larvae of P. xylostella and Pieris brassicae L.Alcohol extracts of hyssop, rosemary, sage, thyme and white clover reduce oviposition by P. xylostella on pieces of brassica leaf in dual-choice tests. Essential oils of sage and thyme reduce oviposition on pieces of brassica leaf. Feeding, in dual-choice tests, by final instar P. xylostella and P. brassicae larvae is reduced by application of alcohol extracts of herbs.
Résumé Des plantes médicinales ont traditionnellement été utilisées en association avec des plantes cultivées dans l'espoir que leur odeur repousserait les insectes nuisibles. Des extraits à l'alcool et des essences volatiles de labiées médicinales ont été essayés au laboratoire pour examiner leur effets répulsif et dissuadant pour la ponte de Plutella xylostella et l'alimentation des chenilles de P. xylostella et Pieris brassicae. Les extraits alcooliques d'hysope, de romarin, de sauge, de thym et de trèfle blanc réduisent la ponte de P. xylostella sur des morceaux de feuilles de chou traitées. Les essences volatiles de sauge et de thym réduisent la ponte de P. xylostella sur des morceaux de feuilles de chou dans des expériences de choix. L'alimentation des chenilles de dernier stade de P. xylostella et P. brassicae dans des expériences de choix est réduite par l'application d'extraits alcooliques des labiées médicinales.
  相似文献   

13.

Background

Sensitive and specific detection of malarial parasites is crucial in controlling the significant malaria burden in the developing world. Also important is being able to identify life threatening Plasmodium falciparum malaria quickly and accurately to reduce malaria related mortality. Existing methods such as microscopy and rapid diagnostic tests (RDTs) have major shortcomings. Here, we describe a new real-time PCR-based diagnostic test device at point-of-care service for resource-limited settings.

Methods

Truenat® Malaria, a chip-based microPCR test, was developed by bigtec Labs, Bangalore, India, for differential identification of Plasmodium falciparum and Plasmodium vivax parasites. The Truenat Malaria tests runs on bigtec’s Truelab Uno® microPCR device, a handheld, battery operated, and easy-to-use real-time microPCR device. The performance of Truenat® Malaria was evaluated versus the WHO nested PCR protocol. The Truenat® Malaria was further evaluated in a triple-blinded study design using a sample panel of 281 specimens created from the clinical samples characterized by expert microscopy and a rapid diagnostic test kit by the National Institute of Malaria Research (NIMR). A comparative evaluation was done on the Truelab Uno® and a commercial real-time PCR system.

Results

The limit of detection of the Truenat Malaria assay was found to be <5 parasites/μl for both P. falciparum and P. vivax. The Truenat® Malaria test was found to have sensitivity and specificity of 100% each, compared to the WHO nested PCR protocol based on the evaluation of 100 samples. The sensitivity using expert microscopy as the reference standard was determined to be around 99.3% (95% CI: 95.5–99.9) at the species level. Mixed infections were identified more accurately by Truenat Malaria (32 samples identified as mixed) versus expert microscopy and RDTs which detected 4 and 5 mixed samples, respectively.

Conclusion

The Truenat® Malaria microPCR test is a valuable diagnostic tool and implementation should be considered not only for malaria diagnosis but also for active surveillance and epidemiological intervention.  相似文献   

14.
A 9-month laboratory study was carried out to determine the impact of herbivory by a moth with shoot-boring larvae, Dichrorampha odorata Brown and Zachariades (Lepidoptera: Tortricidae) on growth and reproductive ability of its host plant, Chromolaena odorata (L.) King and Robinson (Asteraceae), a major invasive alien plant species in southern Africa. Newly hatched D. odorata larvae were inoculated onto 0 (control), 50 and 100% of the shoot tips of C. odorata in the laboratory. At all treatment levels, the basal stem diameter of C. odorata was not affected by D. odorata larval feeding. Larval feeding by D. odorata significantly reduced the height of the main shoot and flower production in C. odorata relative to the control treatment but promoted branching by increasing the number of shoot tips. However, the differences in plant height and number of flowers between the 50 and 100% inoculation levels were not statistically significant. Dichrorampha odorata is the first shoot-tip attacking agent that is being released as a biological control agent against C. odorata in South Africa. In general, the impacts of D. odorata on the weed were relatively small even though statistically significant. The findings of this study suggest that high levels of damage by the moth will modestly reduce the height, flower production, and the competitiveness of C. odorata, thereby contributing to the biological control of the weed in South Africa.  相似文献   

15.
Pathogenicity of Rhabditis blumi Sudhaus against major cruciferous insect pests was evaluated in the lab and greenhouse. In Petri-dish tests against the insects, including Artogeia rapae L., Mamestra brassicae L., and Plutella xylostella L., insect mortality by R. blumi and its associated bacteria was dose and time dependent, which increased with dose (0?C80 dauer juveniles/larva) and time increments. Pathogenicity against fourth-instar larvae was higher than the rate of corresponding third-instar larvae. The highest insect mortality rate was observed in fourth-instar larvae of P. xylostella, followed by A. rapae, and M. brassicae, with mortality rates of 93.5, 88.2, and 77.8?%, respectively. Lethal dose values at 50?% (LD50) of R. blumi were 25.7 dauer juveniles/larva on P. xylostella; 28.0 dauer juveniles/larva on A. rapae; and 40.6 dauer juveniles/larva on M. brassicae, respectively. In greenhouse tests, P. xylostella larvae were most susceptible to nematodes, with insect reduction rate of 88.0?%. The rate varied with vegetable species and persistence time of live nematodes on vegetable leaves after spraying. Nematodes established in cadavers showed positive correlation with nematode dose, whereas nematode persistence on the leaf was inversely related to hours after treatment.  相似文献   

16.
The efficacy of the phosphonate fertilizers, Calphos® (a.i. calcium phosphonate), Magphos® (a.i. magnesium phosphonate and potassium phosphonate) and Phosphoros® (a.i. potassium phosphonate) against two species of root knot nematodes (RKN), Meloidogyne javanica and M. incognita is evaluated. Laboratory experiments showed that Calphos®, Magphos® and their main components inhibited egg hatching and caused 100% mortality of the second stage juveniles (J2s) of the two RKN species; the hatching inhibition effects persisted after transferring the egg masses of both species to water. However, Phosphoros® (0.5%) did not suppress egg hatching or the survival of J2s of both RKN species. No hatching occurred when egg masses were treated for one week with the nematicide Vydate L® (2 ml/l), however, J2s hatched when the Vydate L® treated egg masses were moved to water. The glasshouse study indicated that Magphos®, Calphos® and Phosphoros® reduced root galling caused by M. javanica by 98, 66 and 47%, respectively, in comparison to the untreated controls. Magphos® resulted in the lowest number of root galls formed by M. incognita, the reduction was 84%. In contrast, Calphos® and Phosphoros® reduced galling by 47 and 39%, respectively. The Magphos® treatment resulted in the lowest numbers of egg masses and the lowest reproductive factor (RF) of both nematode species. However, plants treated with Phosphoros® resulted in higher foliage weights compared with the application of the other two fertilizers and the untreated plants.  相似文献   

17.
Plant parasitic nematodes are major pests on upland cotton worldwide and in the United States. The reniform nematode, Rotylenchulus reniformis and the southern root-knot nematode Meloidogyne incognita are some of the most damaging nematodes on cotton in the United States. Current management strategies focus on reducing nematode populations with nematicides. The objective of this research was to integrate additional fertilizer and nematicide combinations into current practices to establish economical nematode management strategies while promoting cotton yield and profit. Microplot and field trials were run to evaluate fertilizer and nematicide combinations applied at the pinhead square (PHS) and first bloom (FB) plant growth stages to reduce nematode population density and promote plant growth and yield. Cost efficiency was evaluated based on profit from lint yields and chemical input costs. Data combined from 2019 and 2020 suggested a nematicide seed treatment (ST) ST + (NH4)2SO4 + Vydate® C-LV + Max-In® Sulfur was the most effective in increasing seed cotton yields in the R. reniformis microplot trials. In R. reniformis field trials, a nematicide ST + (NH4)2SO4 + Vydate® C-LV at PHS supported the largest lint yield and profit per hectare at $1176. In M. incognita field trials, a nematicide ST + 28-0-0-5 + Vydate® C-LV + Max-In® Sulfur at PHS and FB supported the largest lint yields and profit per hectare at $784. These results suggest that combinations utilizing fertilizers and nematicides applied together across the season in addition to current fertility management show potential to promote yield and profit in R. reniformis and M. incognita infested cotton fields.  相似文献   

18.
The aim of this study was to evaluate the effects of adding different concentrations of edible bird’s nest (EBN) which is secreted by swiftlet birds (Aerodramus fuciphagus), into EquiPlus® and E-Z Mixin® extenders on the quality of chilled Arabian stallion semen at various storage times (0, 24 and 48 h). Ten ejaculates were collected from five stallions, and diluted using the two extenders containing 0% (control), 0.12%, 0.24% and 0.24% of EBN + seminal plasma (SP). All the diluted semen samples were then cooled and stored at 5 °C, and examined at 0, 24 and 48 h. Sperm kinetic parameters were assessed using computer assisted sperm analysis (CASA) and viability were assessed using Hoechst33342/PI stain. In both extenders, total motility (TM) and progressive motility (PM) were significantly higher at 0.12% and 0.24% compared to 0.24% + SP at 24 and 48 h. At 0.12%, E-Z mixin® treated semen had significantly higher TM and PM than EquiPlus® at 24 and 48 h. At 0.12% and 0.24%, average path velocity (VAP), straight-line velocity (VSL) and curvilinear velocity (VCL) were significantly higher in E-Z mixin® treated semen compared to EquiPlus® at 24 and 48 h. Comparisons between the two extender types at different concentrations of EBN showed no significant difference in lateral head amplitude (ALH), linearity (LIN), straightness (STR), beat cross frequency (BCF) and viability, irrespective of the storage time. The percentage of viable was significantly higher in E-Z mixin® than EquiPlus® at 0 and 48 h in control and 0.12%. Supplementation of the E-Z mixin® extender with 0.12% and 0.24% EBN concentrations in the absence of SP provided better CASA parameters such as TM, PM, VAP, VSL, and VCL at 24 and 48 h storage time. In conclusion, the results of this study indicated that chilled semen from Arabian stallion that was extended using E-Z mixin® and supplemented with 0.12% and 0.24% EBN concentrations performed better and yielded superior results in sperm kinetic parameters and % viable compared to EquiPlus® at 24 and 48 h storage time.  相似文献   

19.
Mitochondria are key organelles maintaining cellular bioenergetics and integrity, and their regulation of [Ca2+]i homeostasis has been investigated in many cell types. We investigated the short-term Ca-SANDOZ® treatment on brown adipocyte mitochondria, using imaging and molecular biology techniques. Two-month-old male Wistar rats were divided into two groups: Ca-SANDOZ® drinking or tap water (control) drinking for three days. Alizarin Red S staining showed increased Ca2+ level in the brown adipocytes of treated rats, and potassium pyroantimonate staining localized electron-dense regions in the cytoplasm, mitochondria and around lipid droplets. Ca-SANDOZ® decreased mitochondrial number, but increased their size and mitochondrial cristae volume. Transmission electron microscopy revealed numerous enlarged and fusioned-like mitochondria in the Ca-SANDOZ® treated group compared to the control, and megamitochondria in some brown adipocytes. The Ca2+ diet affected mitochondrial fusion as mitofusin 1 (MFN1) and mitofusin 2 (MFN2) were increased, and mitochondrial fission as dynamin related protein 1 (DRP1) was decreased. Confocal microscopy showed a higher colocalization rate between functional mitochondria and endoplasmic reticulum (ER). The level of uncoupling protein-1 (UCP1) was elevated, which was confirmed by immunohistochemistry and Western blot analysis. These results suggest that Ca-SANDOZ® stimulates mitochondrial fusion, increases mitochondrial-ER contacts and the thermogenic capacity of brown adipocytes.Key words: Brown adipocyte, mitochondrial dynamics, calcium, endoplasmic reticulum  相似文献   

20.
Kuschelina bergi (Harold, 1881) is being studied to be evaluated as a natural enemy of Phyla nodiflora var. minor (Hook.) N. O’Leary & Múlgura (Verbenaceae), an invasive weed in Australia. Eggs, and 1st and 3rd instar larvae are described and illustrated for the first time. The following characters distinguish Kuschelina bergi: presence of two medial setae in prosternum, mesosternum and metasternum, absence of tubercle on sternum I and eight setae in abdominal segment IX. The 3rd instar larvae of Kuschelina bergi resemble Kuschelina gibbitarsa (Say) larvae: the body shape and details of mouthparts are similar, but the morphology of the mandible is different, as is the tarsungulus which has a single seta. Differences between Kuschelina bergi and other known larvae of Oedionychina are discussed. New biological data based on laboratory rearing and field observation are also presented and discussed.  相似文献   

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