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1.
For centuries, plants have been used in traditional medicines and there has been recent interest in the chemopreventive properties of compounds derived from plants. In the present study, we investigated the antibutyrylcholinestrasic (anti-BuChE) and antioxidant (against some free radicals) activities of extracts from Rhus pentaphyllum. Aqueous extracts were prepared from powdered R. pentaphyllum roots, leaves and seeds and characterized for the presence of tannins, flavonoids and coumarins. Seeds aqueous extract contained the highest quantities of both flavonoids and tannins (21.12% and 17.45% respectively). In the same way, seeds extracts displayed remarkable inhibition against BuChE over 95%, at 100 μg/ml and with IC50 0.74 μg/ml. In addition, compared to leaves and roots extracts, seeds aqueous extract revealed relatively strong antiradical activity towards the ABTS .+ (IC50 = 0.25 μg/ml) and DPPH (IC50 = 2.71 μg/ml) free radicals and decreased significantly the reactive oxygen species such O2 .- (IC50 = 2.9 μg/ml) formation evaluated by the non-enzymatic generating O2 .- system (Nitroblue tetrazolium/riboflavine). These data suggest that the anti-BuChE activities mechanism of these extracts occurs through a free radical scavenging capacities. The present study indicates that extracts of Rhus pentaphyllum leaves, seeds and roots are a significant source of compounds, such as tannins, flavonoids and coumarins, with anti-BuChE and antioxidant activities, and thus may be useful for chemoprevention.  相似文献   

2.
Analysis of Leucaena leucocephala from various localities in Western Nigeria shows that young leaves, pods and seeds contain more crude protein but lower crude fibre and ether extract than mature ones. The crude fat component was higher in the seeds (4.6% and 5.5% for green and ripe seeds, respectively) than in any other edible part of the plant, while the green and brown seed coats contain the least amount of ether extract and total ash. The mineral composition of the dry matter of mature leaves is 2.8% calcium, 0.26% phosphorus, 0.37% magnesium, 1.78% potassium, 0.21% sodium and 0.12% iron.  相似文献   

3.
Ni BR  Pallardy SG 《Plant physiology》1992,99(4):1502-1508
Comparative responses of net photosynthesis (A) to water stress in woody species from a variety of habitats were studied to assess the relationship between photosynthetic attributes and drought tolerance. Stomatal and nonstomatal limitations to A were compared in three-month-old white oak (Quercus alba L.), post oak (Quercus stellata Wangenh.), sugar maple (Acer saccharum Marsh.), and black walnut (Juglans nigra L.) seedlings during a drying cycle. Relative stomatal limitation of photosynthesis (I) was less than 50% in all species except for Q. stellata seedlings subjected to severe water stress. No significant changes in I were observed in Q. alba and J. nigra before, during, and after drought. In A. saccharum, I was generally low and decreased significantly under water stress. Under well-watered conditions, A was highest in Q. stellata, intermediate in Q. alba, and lower in A. saccharum and J. nigra. High A in well-watered Q. stellata was associated with high stomatal conductance and carboxylation efficiency, whereas low A was associated with low stomatal conductance and carboxylation efficiency in A. saccharum and low stomatal conductance, low carboxylation efficiency, and high CO2 compensation point in J. nigra. Under severe water stress, A, carboxylation efficiency, and stomatal conductance decreased substantially in all species; however, Q. stellata had the highest carboxylation efficiency and lowest CO2 compensation point under these conditions. After 5 days at high soil moisture after drought, stomatal and mesophyll components of A in A. saccharum and J. nigra had not recovered to predrought levels, whereas they had completely recovered in Q. stellata and Q. alba. The photosynthetic apparatus, especially mesophyll components, of drought-tolerant Quercus species showed either less inhibition under water stress, superior recovery to predrought capacity, or both. Exposure of the leaves to 14CO2 indicated apparent asymmetric stomatal closure for mildly water-stressed seedlings, but not for leaves of well-watered, severely stressed, or rehydrated plants. These results suggest that patchy stomatal closure under mild water stress might be important for water stress-induced inhibition of photosynthesis, but not under the more severe water stress imposed in this study.  相似文献   

4.
运用系统溶剂法和生物测定法,以栎属7种植物种子为材料,研究了其种皮、胚(胚及周围部分子叶)和子叶(远离胚端2/3子叶)1.0 g/mL和0.5 g/mL浓度甲醇等浸提液以及各有机相对白菜种子萌发的影响。结果表明:栓皮栎、锐齿栎、蒙古栎、沼生栎和麻栎甲醇浸提液均能显著降低白菜种子发芽率、根长和苗高,且对发芽率的抑制作用逐渐降低;夏栎和房山栎甲醇浸提液对白菜种子发芽率没有显著影响,但对根长和苗高有一定的抑制作用;种子不同部位甲醇浸提液的抑制作用表现为胚>子叶>种皮,且甲醇高浓度浸提液的抑制作用大于低浓度的抑制作用;甲醇相对白菜种子发芽率、苗高或根长的抑制作用最强,其次是乙酸乙酯相,其它溶剂相萃取液的抑制作用不明显。栎属种子甲醇浸提液及各有机相对白菜种子苗高和根长的抑制作用强于对发芽率的影响,说明栎属种子中所含抑制物质主要是限制自身根和芽的生长,可能是造成延迟萌发和出苗不整齐的原因。  相似文献   

5.
The ethyl acetate extract of leaves, seeds and flowers of Heracleum persicum, a medicinal plant of Iran (family Apiaceae) inhibited growth and aflatoxin (AF) production of Aspergillus parasiticus. On the basis of total dry weight growth inhibition by the leaf extract ranged from 17.1 to 36.9 %, by the flower extract from 32.2 to 75.6 %, and by the seed extract from 27.5 to 74.9 %. Production of AFB1 and AFG1 was inhibited in a dose-dependent manner, with a reduction of 88.5–100 % at the highest concentration of 8,000 μg/ml tested. The flower extract decreased ergosterol content of hyphae most significantly. Electron microscopy further revealed structural defects in the treated A. parasiticus including disruption of cytoplasmic membranous compartments, detachment of plasma membrane from the cell wall, and disorganization of hyphal compartments. Collapsed hyphae without conidiation, shorter branches and undifferentiated hyphal tips were also evident. The results indicate that H. persicum extract exerts antifungal and anti-AF activities by disrupting plasma membrane integrity and permeability mainly through interference with ergosterol biosynthesis. These results show that H. persicum can serve as a potent and safe alternative for inhibiting toxigenic aspergilli growth and thus preventing AF contamination of foods and feeds.  相似文献   

6.
This study aimed to isolate fungi from leaves, petals, stalks and stamens of Nymphaea lotus and Nymphaea stellata and explore their bioactive potential with respect to antimicrobial activity and their cytotoxicity on human cell lines. The totals of 210 fungal isolates were obtained from 640 segments. The highest isolation rate was found in petal segments (0.44), while stamens yielded the lowest isolation rate (0.13). One hundred and ninety–five fungal extracts were evaluated for their efficiency against ten pathogenic microorganisms by colorimetric broth microdilution tests. Cell hexane extract from Eupenicillium levitum FNL036 (FNL036CH) gave the strongest antifungal activity against Cryptococcus neoformans and Talaromyces marneffei with minimum inhibitory concentration of 0.5?μg/mL and affected cell morphology of the test microorganisms. Moreover, this extract was non–cytotoxic to human embryonic kidney 293 (293T) and human keratinocytes (HaCAT) cell lines with 50% inhibitory concentration (IC50) values above 100?μg/mL. This finding confirmed that fungi derived from these two Nymphaea species were a novel source of bioactive metabolites.  相似文献   

7.
Piper nigrum is a widely used plant in traditional remedies and known for its numerous biological properties. However, fraction-based antioxidant activity and their antimutagenic potential are not yet fully investigated. Different extracts of the seeds P. nigrum were obtained by sequential extraction in different solvents. All extracts were evaluated for antibacterial and antioxidant activities using different methods. The most active fraction was analyzed for antimutagenic activity using the Ames Salmonella test. The antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) was found to be more prominent compared to ESβL producing Klebsiella pneumoniae isolates. The MIC values were found to be lower against MRSA than K. pneumoniae. The extract showing highest antioxidant activity (methanol extract) was further tested for antimutagenic activity both against direct and indirect-acting mutagens. A varying level of antimutagenic activity was shown by methanol extract at highest tested concentration (200 µg/plate). Alkaloids, phenols, and flavonoids were detected as major class of compounds in methanol extract. Gas chromatography-mass spectrometry (GC–MS) analysis showed the presence of various phytocompounds. Based on molecular docking of two major active phytocompounds (piperine and copaene), they were found to interact at the minor groove of DNA. Molecular dynamics (MD) simulation revealed that both the ligands were quite stable with DNA under physiological conditions. The ability of phytocompounds to interact with DNA might be reducing the interaction of mutagens and could be one of the possible mechanism of anti-mutagenic activity of P. nigrum extract. This study highlights the antioxidant and antimutagenic potential of Piper nigrum. The role of phytocompounds present in the bioactive extract is needed to be explored further for herbal drug research.  相似文献   

8.
Growing patterns of pediculocidal drug resistance towards head louse laid the foundation for research in exploring novel anti-lice agents from medicinal plants. In the present study, various extracts of Pongamia pinnata leaves were tested against the head louse Pediculus humanus capitis. A filter paper diffusion method was conducted for determining the potential pediculocidal and ovicidal activity of chloroform, petroleum ether, methanol, and water extracts of P. pinnata leaves. The findings revealed that petroleum ether extracts possess excellent anti-lice activity with values ranging between 50.3% and 100% where as chloroform and methanol extracts showed moderate pediculocidal effects. The chloroform and methanol extracts were also successful in inhibiting nymph emergence and the petroleum ether extract was the most effective with a complete inhibition of emergence. Water extract was devoid of both pediculocidal and ovicidal activities. All the results were well comparable with benzoyl benzoate (25% w/v). These results showed the prospect of using P. pinnata leave extracts against P. humanus capitis in difficult situations of emergence of resistance to synthetic anti-lice agents.  相似文献   

9.
The present study explored the phytochemicals, antibacterial, antioxidant and cytotoxic effect of Tridax procumbens leaves. The leaves were dried and extracted with various organic solvents. The leaves contained the phytochemicals such as alkaloids, carbohydrates, polyphenols and tannins respectively. Antimicrobial potentials of the extracts were determined by performing the disc diffusion techniques. Results revealed that different organic solvents extracts namely methanol, ethanol and ethyl acetate extracts documented comparatively good activity against the studied microbial strains. The methanol extract of leaves of T. procumbens showed combatively better antioxidant potential. The tested plant leaf extract showed high activity against human lung cancer cells than breast cancer cell lines. 250 µg/ml plants extract showed 84 ± 2.8% toxicity against human lung cancer cells.  相似文献   

10.
The toxicity of organic plant extracts to Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) was assessed for three tropical plant species: branches, leaves, and seeds of Annona montana (Annonaceae), branches of Aristolochia paulistana (Aristolochiaceae), and leaves and branches of Casearia sylvestris (Salicaceae). The screening assay resulted that the extracts of A. montana seeds obtained with hexane (LC50?=?534.75 mg kg?1 and LT50?=?6.10 days) and with dichloromethane (LC50?=?424.67 mg kg?1 and LT50?=?5.03 days) were the most promising treatments, followed by the extract prepared from A. montana leaves with hexane (LC50?=?837.70 mg kg?1 and LT50?=?4.90 days). Moreover, extracts (at 1,500 mg kg?1) prepared from C. sylvestris branches with dichloromethane and A. paulistana with hexane caused significant mortality (37% and 41.5%, respectively) beyond sublethal effects on S. zeamais. Therefore, based on the biological assays, extraction yield, and evaluation of the chromatographic profile of the crude extracts by TLC, the hexane extract of A. montana seeds was selected and fractioned using liquid-liquid partitioning. The hydroalcoholic fraction caused mortality of 55.5%, significantly superior to dichloromethane fraction, which caused 35.5% of mortality. Chemical analyses (1H NMR, HPLC, and TLC) were performed, and the results showed the presence of alkaloids and acetogenins in both active fractions, which have been associated with bioactivity. Therefore, extracts prepared from A. montana seeds (especially) is an interesting source of new compounds with promising grain-protectant properties.  相似文献   

11.
A new glycoside was isolated from a 60% methanol extract of dried leaves and stems of Annona squamosa. Its chemical structure was determined as 4-(-2-nitroethyl)-1-[(6-O-β-d-xylopyranosyl-β-d-glucopyranosyl)oxy] benzene.  相似文献   

12.
Infusions of the leaves and seeds of Annona crassiflora Mart. are commonly employed in the treatment of diarrhoea, snakebites, tumours and disorders of the hair and scalp. The aim of the present study was to investigate the cytotoxic and genotoxic properties of ethanolic extracts of A. crassiflora by evaluating their effects on germination, root elongation, chromosome structure and the cell division of Lactuca sativa (lettuce). The experiment followed a randomized design involving the treatment of L. sativa seeds with ethanolic extracts from leaves and seeds of A. crassiflora applied at ten concentrations (0.0125, 0.025, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0, and 1.2 mg/L) and with five repetitions per treatment. Seeds of L. sativa exposed for 48 h to A. crassiflora leaf extract at concentrations ≥ 0.1 mg/L, or to seed extracts at concentrations ≥ 0.2 mg/L, showed germination percentages that were significantly (p < 0.05) lower than those of seeds exposed to aqueous ethanol control. Exposure of L. sativa seedlings to leaf (but not seed) extracts of A. crassiflora produced significant (p < 0.05) reductions in the mitotic indices of root meristem cells of lettuce and induced chromosome and nuclear abnormalities in the root cells. The presence of chromosome stickiness, bridges, fragments, laggard chromosomes and nuclear condensation were also observed. The cytogenetic effects observed suggest that folkloric medicines prepared with extracts of the leaves or seeds of A. crassiflora should be employed with caution.  相似文献   

13.
Siderastrea stellata is a common scleractinian coral that inhabits shallow reefs off the coast of Brazil. This species is considered to be very resistant to temperature and salinity variations and water turbidity, demonstrating great ecological plasticity and adaptability to environmental changes. Samples of S. stellata were taken from the Cabo Branco coastal reefs near João Pessoa, Brazil, every month for two years and analyzed using PCR and Restriction Fragment Length Polymorphisms of SSU rDNA techniques. The data indicated that during the study period S. stellata hosted only one SSU rDNA genotype of Symbiodinium with the RFLP pattern of clade C. The presence of clade C zooxanthellae in S. stellata in northeastern Brazilian reefs shows the wide geographical distribution of this clade, and it may aid bleaching recovery in S. stellata. Furthermore, the association of S. stellata with a zooxanthellae clade considered to be one of most resistant to bleaching may help to explain the high ecological plasticity of this scleractinian species, its capacity to reverse bleaching, and its high resistance and resilience to environmental disturbances.  相似文献   

14.
An experiment was conducted to introduce the entomopathogen Beauveria bassiana (Balsamo) Vuillemin (Ascomycota: Hypocreales) as an endophyte in jute (Corchorus olitorius), a bast fibre crop through seed treatment. Colonization of root, leaf, stem, capsule, and seed were assessed through plating on selective medium and PCR based detection using B. bassiana specific SCAR markers. Endophytic colonization was detected in all the plants grown from treated seeds, but all the plant parts were not colonized. Colonization was detected in leaves, stems, and green capsules but not in roots and seeds. The endophytic colonization was influenced by both plant part and sampling period. Colonization was greater in leaves (55.87%) compared to stems (12.53%) and capsules (42.44%). The percent colonization was higher in case of 60?days old plants (43.34%) than in 30?days (23.89%) and 120?days (35.39%) old plants. As B. bassiana has already been reported to be pathogenic on jute pests, namely semilooper (Anomis sabulifera) and bihar hairy caterpillar (Spilosoma obliqua), its season long endophytic colonization within jute plant suggests a novel approach of biological control of these pests through seed treatment with the entomopathogen.  相似文献   

15.
Defoliation occurs in castor due to several reasons, but the crop has propensity to compensate for the seed yield. Photosynthetic efficiency in terms of functional (gas exchange and chlorophyll fluorescence) and structural characteristics (photosynthetic pigment profiles and anatomical properties) of castor capsule walls under light- and dark-adapted conditions was compared with that of leaves. Capsule wall showed high intrinsic efficiency of photosystem II (F v/F m, 0.82) which was comparable to leaves (F v/F m, 0.80). With increasing photon flux densities (PFD), actual quantum yields and photochemical quenching coefficients of the capsule walls were similar to that in leaves, while electron transport rates reached a maximum corresponding to about 118 % of the leaves. However, maximum net photosynthetic rate of the capsule walls (2.60 µmol CO2 m?2 s?1) was less than one-fourth of the leaves (15.67 µmol CO2 m?2 s?1) at the CO2 concentration of 400 µmol mol?1, and the difference was attributed to about 80 % lower stomatal density and the 75 % lower total chlorophyll content of capsule walls than the leaves. Furthermore, seed weight in dark-adapted capsules was 2.70–12.42 % less as compared to the capsules developed under light. The results indicate that castor capsule walls are photosynthetically active (about 15–30 % of the leaves) and contribute significantly to carbon fixation and seed yield accounting for 10 % photoassimilates towards seed weight.  相似文献   

16.
The extracts prepared from various areal parts of the Adenium obesum (Forssk.) Roem. & Schult. (Family: Apocynaceae) including leaves, fruit and seeds ethanolic extracts and seed aqueous extract were evaluated against MCF-7 cells in order to investigate its potential of cytogenotoxicity and induction of apoptosis. The ethanolic seeds extract had comparatively higher cytotoxicity (IC50?~?337?µg/ml). Further, apoptosis and DNA damaging potential of seeds ethanolic extract was analyzed by applying multiple sub-lethal concentrations and durations. Flow cytometry results revealed that maximum percentage of early apoptosis (37%) and late apoptosis (35%) were observed after 12?h exposure in concentrations 200?µg/ml and 300?µg/ml, respectively. Similarly, the higher effect of extract in terms of DNA damage by alkaline comet assay was registered after 12?h treatment at concentrations 200 and 300?µg/mL. The calculated total damage score (TDS) for these concentrations were 614 and 617, respectively. The above findings indicate that A. obesum ethanolic seeds extracts has cytogenotoxic properties that could be further explored for the potential source of chemotherapeutic lead against cancer.  相似文献   

17.
The widespread occurrence of extended spectrum β-lactamases (ESβLs) producing enteric bacteria and their co-resistance with flouroquinolones has impaired the current antimicrobial therapy. This has prompted the search for new alternatives through synergistic approaches with herbal extracts. In this study Carum copticum (seeds) was extracted first in methanol and then subsequently extracted in different organic solvents. MIC of plant extracts, ciprofloxacin and thymol was determined by broth micro-dilution method using TTC. Synergism between plant extracts and ciprofloxacin was assayed by the checkerboard method. Chemical constituents of active extracts were analyzed by GC-MS. Methanolic, hexane and ether extract of Carum copticum exhibited significant antibacterial activity with MIC values ranged from 0.25 mg/ml to 2.0 mg/ml. Synergy analysis between Carum copticum extracts and ciprofloxacin combinations revealed FIC index in the range of 0.093–0.25. About 81% ciprofloxacin resistant ESβL producing enteric bacteria were re-sensitized in the presence of 15.6–250 μg/ml of methanolic extract of Carum copticum. Moreover, ciprofloxacin showed 8 to 64 folds reduction in MIC in presence of 250 and 500 μg/ml of hexane extract. Whereas, 4–32 folds reduction in MIC of ciprofloxacin was achieved in the presence of 31.25 and 62.5 μg/ml of ether extract, indicating synergistic enhancement of drug activity. The chemical analysis of hexane and ether extracts by GC-MS revealed the common occurrence of one or more phenolic hydroxyl at different locations on benzene ring. This study demonstrated the potential use of herbal extract of Carum copticum in combination therapy against ESβL producing bacteria.  相似文献   

18.
Light harvesting and utilization by chloroplasts located near the adaxial vs the abaxial surface of sun and shade leaves were examined by fluorometry in two herbaceous perennials that differed in their anatomy and leaf inclination. Leaves of Thermopsis montana had well-developed palisade and spongy mesophyll whereas the photosynthetic tissue of Smilacina stellata consisted of spongy mesophyll only. Leaf orientation depended upon the irradiance during leaf development. When grown under low-light levels, leaves of S. stellata and T. montana were nearly horizontal, whereas under high-light levels, S. stellata leaves and T. montana leaves were inclined 600 and 300, respectively. Leaf inclination increased the amount of light that was intercepted by the lower leaf surfaces and affected the photosynthetic properties of the chloroplasts located near the abaxial leaf surface. The slowest rates of quinone pool reduction and reoxidation were found in chloroplasts located near the adaxial leaf surface of T. montana plants grown under high light, indicating large quinone pools in these chloroplasts. Chloroplasts near the abaxial surface of low-light leaves had lower light utilization capacities as shown by photochemical quenching measurements. The amount of photosystem II (PSII) down regulation, measured from each leaf surface, was also found to be influenced by irradiance and leaf inclination. The greatest difference between down regulation monitored from the adaxial vs abaxial surfaces was found in plants with horizontal leaves. Different energy dissipation mechanisms may be employed by the two species. Values for down regulation in S. stellata were 2–3 times higher than those in T. montana, while the portion of the PSII population which was found to be QB nonreducing was 4–6 times lower in high light S. stellata leaves than in T. montana. All values of Stern-Volmer type nonphotochemical quenching (NPQ) from S. stellata leaves were similar when quenching analysis was performed at actinic irradiances that were higher than the irradiance to which the leaf surface was exposed during growth. In contrast, with T. montana, NPQ values from the abaxial leaf surface were up to 45% higher than those from the adaxial leaf surface regardless of growth conditions. The observed differences in chloroplast properties between species and between the adaxial and abaxial leaf surfaces may depend upon a complex interaction among light, leaf anatomy and leaf inclination.  相似文献   

19.
Calotropis procerawas evaluated as a potential source of hydrocarbons. Hexane Soxhlet extractions of oven-dried whole plants, stems, leaves and pods (≧6mo of age) yielded 4.35, 3.83, 5.13, and 9.37% (w/w) hexane extract (HE), respectively. The HE from whole plants has a density of 0.9299 glcm3, 0.71% total ash, 9973.4 callg and 78.03, 11.22 and 10.71% carbon, hydrogen and oxygen, respectively. Similar values were obtained from stems, leaves and pods when analyzed separately. Methanol Soxhlet extractions of residues previously extracted with hexane yielded 16.14, 18.50, 12.15 and 20.68% (w/w) methanol extract (ME) from whole plants, stems, leaves and pods, respectively. The ME from whole-plant residues had a density of 1.2267 glcm3, 12.05% total ash, 4,647.4 callg, and 40.88, 6.86, and 30.05% carbon, hydrogen and oxygen, respectively. Similar values were obtained from stems, leaves and pods when analyzed separately.  相似文献   

20.
Phytochemicals and anti-inflammatory activity were investigated in the leaves of Pellacalyx saccardianus from the Rhizophoraceae family. The powdered leaves were extracted using methanol in a soxhlet extractor. Purification of the methanol extract yielded two new compounds, (3S)(6R)-3-(4′-hydroxybenzyl)-6-(6″-hydroxyphenethyl)-2,2-dimethyl-piperidin-4-one and 1,2-O-(1-methylethylidene)fucoside, together with six known compounds, β-amyrin palmitate, squalene, 24-ethylcholesta-5,22,25-trien-3β-ol, 5R-hydroxy-1,7-bis(5-hydroxyphenyl)heptan-3-one, 1,7-bis(4-hydroxyphenyl)hept-4-en-3-one and methyl-l-fucoside. An anti-inflammatory assay using COX-2 revealed that β-amyrin palmitate possessed the highest inhibitory effect (96.8%) at the lowest concentration (0.01 μM), which was higher than that of the positive controls, resveratrol (90.2%, 0.01 μM) and indomethacin (79.20%, 100 μM). This is the first report on the isolation of phytochemicals from the leaves of P. saccardianus and their anti-inflammatory activity.  相似文献   

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