Differential belowground allelopathic effects of leaf and root of Mikania micrantha

This study evaluates the relative contributions of leaves and roots to the belowground allelopathic effects of Mikania micrantha. The hypothesis that leaves contribute more to the allelopathic effect than roots was experimentally tested. We assessed the allelopathic effects of aqueous extracts from Mikania leaves and roots on the seed germination and seedling growth of two co-occurring woody plants in southern China, Lagerstroemia indica L. and Robinia pseudoacacia L. The results showed that the aqueous extracts from Mikania leaves and roots had inhibitory effects on the woody species. Allelopathic activity depended on the concentration of the extracts, target species, and the extract sources (i.e., leaves vs. roots of Mikania). Leaf extract showed stronger allelopathic effects than root extract on germination percentage, initial germination time, speed of germination, and shoot height; while root extract had greater allelopathic effects on roots than leaf extract. The latter phenomenon might greatly promote the invasion success of Mikania due to more direct and effective allelopathy of root. Our results suggest that allelopathy of root extract on belowground biomass might be greater than that of leaf extract for some species in contrast allelopathy of leaf extract on belowground biomass might also be greater than that of root extract for other species, at least for their effects on root growth of the target species.     

Aqueous fruit extracts of Azadirachta indica induce systemic acquired resistance in barley against Drechslera graminea

The study reported here primarily focuses on whether fruit extracts of Azadirachta indica Juss. (Neem) can induce systemic acquired resistance (SAR) in Hordeum vulgare against Drechslera graminea. A single leaf from each of the 1-month-old seedlings grown in 50 pots was treated with neem extract. Seven samples were collected at 12-h intervals for estimation of salicylic acid (SA) content and activities of phenylalanine ammonia lyase (PAL) and peroxidase (PO). Disease incidence was recorded on uninoculated leaves after 2 weeks and on newly emerged leaves after 3 weeks of inoculation of spores of the pathogen. Treatment of single leaf of barley seedlings with aqueous fruit extract of neem could protect the untreated and later emerging leaves of these seedlings from infection by leaf stripe pathogen. The concentration of SA and activities of PAL and PO were significantly higher in untreated leaves of seedlings given a single leaf treatment with neem fruit extract. The results show that neem fruit extract induced SAR in barley seedlings against D. graminea. The results of the study are significant for developing an environment-friendly biocide, which could induce SAR in crop plants leading to efficient management of pathogens     

巨桉不同状态叶片浸提液对萝卜幼苗形态和抗性生理特性的影响

以珍珠岩作为基质,选择4年生巨桉(Eucalyptus grandis)嫩叶(T1)、老叶(T2)、表层凋落叶(T3)、腐解凋落叶(T4)4种状态的叶片,每种状态叶片设置3个浸提液浓度水平[分别称取风干叶片30g、15g和7.5g加入900mL蒸馏水进行浸提,以蒸馏水为对照(CK)],采用水培法研究了不同状态叶片浸提液对萝卜(Raphanus sativus)幼苗形态生长和抗性生理特性的影响。结果显示:(1)巨桉不同状态叶片浸提液显著抑制了萝卜幼苗的根长,其中嫩叶的抑制作用最强,腐解凋落叶抑制作用最弱。(2)各状态叶片浸提液处理后萝卜幼苗中过氧化氢酶(CAT)和过氧化物酶(POD)的活性均呈现升高趋势,嫩叶各浓度处理以及其他状态叶片的高浓度处理下超氧化物歧化酶(SOD)活性升高,而其余浓度处理的SOD活性降低。(3)各状态叶片浸提液处理萝卜幼苗的丙二醛(MDA)含量在低浓度处理时低于CK,其余处理下则高于CK。(4)嫩叶各浓度处理萝卜幼苗的可溶性糖(SS)含量显著高于CK,且随着老叶和表层凋落叶浸提液浓度的升高,幼苗SS含量先升后降,腐解凋落叶各浓度处理下则呈渐增的趋势;而可溶性蛋白(SP)含量则随浸提液浓度的增加而升高,且T2和T3两种状态叶片的各浓度处理与CK差异显著。研究表明,巨桉不同状态叶片浸提液对萝卜幼苗生长和抗性生理产生了强烈的抑制作用,其中以嫩叶最强,老叶和表层凋落叶次之,腐解凋落叶最弱。     

Podophyllum hexandrum aqueous extract as a potential free radical scavenger

Abstract

The present study was undertaken to evaluate the effect of the aqueous extract of Podophyllum hexandrum against free radical-mediated damage and also explore its anticancer activity. The extract exhibited significant activity in scavenging 1, 1-diphenyl-2-picryl-hydrazyl radicals, ^?OH radical-mediated DNA damage, and lipid peroxide production in rat liver microsomes. The extract was also tested for its reducing abilities. The activity of liver marker enzymes and antioxidant defense enzymes in rat liver homogenate was assessed in control and carbon tetrachloride (CCl₄)-treated animals. It was observed that CCl₄-induced changes viz., increases in the activities of aspartate aminotransferase, alanine aminotransferase, and lactate dehydrogenase, a decrease in reduced glutathione as well as decreases in the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase. All these parameters showed reversal when pretreated with aqueous extract of P. hexandrum. Podophylotoxin and etoposide are the two known anticancer agents derived from P. hexandrum and interestingly the aqueous extract of P. hexandrum showed a typical DNA ladder formation in HL-60 cells confirming its role as an inducer of apoptosis. The results obtained suggest that the plant extract exhibits inhibition of and free radical production and lipid peroxidation, increase in antioxidant enzyme activities, revealing its antioxidant properties, and is also able to show potent anticancer activity as depicted by its ability to cause fragmentation of DNA.     

First report of Phoma betae on Aloe vera in India

Leaf spot disease of A. vera was observed in nurseries of Gwalior city afterthe post-rainy season. As the disease progressed, the tip of the leaf shrank, then dried and eventually broke. The causal agent was identified as Phoma betae A.B. Frank. This is the first report of leaf spot disease on Aloe vera caused by P. betae in India.     

Radioprotective activity of Polyalthia longifolia standardized extract against X-ray radiation injury in mice

The radioprotective effect of Polyalthia longifolia was studied in mice. P. longifolia treatment showed improvement in mice survival compared to 100% mortality in the irradiated mice. Significant increases in hemoglobin concentration, and red blood cell, white blood cell and platelet counts were observed in the animals pretreated with leaf extract. Pre-irradiation administration of P. longifolia leaf extract also increased the CFU counts of the spleen colony and increased the relative spleen size. A dose-dependent decrease in lipid peroxidation levels was observed in the animals pretreated with P. longifolia. However, although the animals pretreated with P. longifolia exhibited a significant increase in superoxide dismutase and catalase activity, the values remained below normal in both liver and the intestine. Pre-irradiation administration of P. longifolia also resulted in the regeneration of the mucosal crypts and villi of the intestine. Moreover, pretreatment with P. longifolia leaf extract also showed restoration of the normal liver cell structure and a significant reduction in the elevated levels of ALT, AST and bilirubin. These results suggested the radioprotective ability of P. longifolia leaf extract, which is significant for future investigation for human applications in developing efficient, economically viable, non-toxic natural and clinically acceptable novel radioprotectors.     

Trifolium pratense (Red Clover) Improve SIRT1 Expression and Glycogen Content in High Fat Diet‐Streptozotocin Induced Type 2 Diabetes in Rats

Flowering tops of Trifolium pratense L. (Fabaceae) are known for its traditional medicinal values. In present study, our aim was to investigate effect of standardized aqueous extract of flowering tops of Trifolium pratense L. on insulin resistance and SIRT1 expression in type 2 diabetic rats. Type 2 diabetes was induced by feeding high fat diet and administering low dose of streptozotocin. Diabetic animals were treated with standardized aqueous extract at three different doses. Parameters such as blood glucose, lipid profile, glycohemoglobin, insulin sensitivity, HOMA‐IR and liver glycogen content were measured. Changes in morphology and expression of SIRT1 in pancreatic tissue were measured in histopathological and immunohistological studies. Aqueous extract treatment showed reduction in hyperglycemia and improved insulin sensitivity. Extract treatment also showed reduction in formation of glycated hemoglobin and improved liver glycogen level. Histopathological study revealed protecting effect of extract in pancreatic tissue against hyperglycemia induced damage. Treatment increased expression of SIRT1 in rat pancreatic tissue. Results indicate that the aqueous extract of Trifolium pratense had beneficial role in improving insulin sensitivity and SIRT1 expression.     

Assessment of Phytochemical Analysis,Nutritional Composition and Antimicrobial Activity of<i> Moringa oleifera</i>

Moringa oleifera is a miracle plant rich in nutrients, antioxidants, and antibiotic properties. Present study was designed to evaluate various biochemical attributes of leaves and flowers of M. oleifera. Plant parts (leaves, flowers) of M. oleifera, collected from different roadsides of Multan district, Punjab, Pakistan, were used as experimental material. Result indicates that alkaloids, saponin, carbohydrates, fats, and protein had a high value in the aqueous extract of both leaves and flowers of M. oleifera. Whereas phenol content was high in methanolic leaves extract and the phenol contents were high in aqueous extract of flowers. The extract yield of M. oleifera leaves and flowers both showed a higher percentage in aqueous extract (57.5%), followed by methanol extract and lowest in ethyl acetate extract. Flavonoids contents were higher in ethyl acetate extract of leaves (33.67%) and aqueous extract of flowers (53.71%). While crude fiber was high in methanolic extract of leaves (12.40%) and in flowers crude fiber was high in ethyl acetate extract (15.86%). The moisture contents were higher in leaves (8.87%) than flowers (7.3%) and similarly, ash percentage in flowers (52.60%) than leaves (41.84%). Ethyl acetate extracts of M. oleifera leaves show antibacterial activity against Pseudomonas aeruginosa while methanolic extract of M. oleifera flowers shows antibacterial activity against Xanthomonas sp. Maximum growth inhibits show in all extracts of leaves against Aspergillus flavus, F. oxysporum, and P. glabrum except for the concentrated aqueous extract of leaves. While in flowers maximum growth inhibits all extracts against P. glabrum, A. niger, and A. flavus except the diluted ethyl acetate extract. Phytochemicals present in different parts of moringa have significant edible and commercial potential. Moringa extracts exhibited significant antimicrobial activity, therefore have applications in pharmaceuticals.     

Fungal utilization of organophosphate pesticides and their degradation byAspergillus flavus andA. sydowii in soil

Fungal species were isolated which utilize organophosphate pesticides,viz. phosphorothioic (pirimiphos-methyl and pyrazophos), phosphorodithioic (dimethoate and malathion), phosphonic (lancer) and phosphoric (profenfos) acid derivatives. Pesticide degradation was studiedin vitro andin vivo (soil).Aspergillus flavus, A. fumigatus, A. niger, A. sydowii, A. terreus, Emericella nidulans, Fusarium oxysporum andPenicillium chrysogenum were isolated from pesticide-treated wheat straw. The number ofA. sydowii colonies was significantly promoted by 1 mmol/L pirimiphos-methyl, pyrazophos, lancer, dimethoate and malathion when used as phosphorus sources and by pirimiphos-methyl and pyrazophos when used as carbon sources. The number ofA. flavus colonies increased with 0.5 mmol/L lancer and malathion used as the only carbon sources.A. sydowii, A. niger, A. flavus, E. nidulans andF. oxysporum grew on, and utilized, 5 pesticides as phosphorus source and showed more than 50% mass growth.A. sydowii, A. flavus andF. oxysporum phosphatase hydrolyzed the pesticides suggesting that these species are important pesticide degraders.A. sydowii produced higher amounts of the phosphatase thanA. flavus andF. oxysporum. The enzyme was highly active against pyrazophos, lancer and malathion used as the only sources of organic phosphate.A. flavus andA. sydowii phosphatases efficiently hydrolyzed pesticides at 300 ppm in soil, the degradation at 1000 ppm was lower. Mineralization of 1000 ppm pesticides in soil amended with wheat straw was higher than in nonamended soil. All added pesticides except profenfos were degraded within 3 weeks. Lyophilized adapted biomass ofA. flavus andA. sydowii could thus be used for field biodegradation of these pesticides.     

Euphorbia cotinifolia (Euphorbiaceae): a promising alternative for leaf cutting ant Atta cephalotes (Hymenoptera: Formicidae) control

Field observations indicate that Euphorbia cotinifolia escapes attack by leaf cutting ants, which are the largest generalist herbivores of the Neotropics. We used controlled bioassays to evaluate the effect of E. cotinifolia on the foraging of the Atta cephalotes ant. In a free-choice trial, to five colonies were offered Mangifera indica leaves with a 10% aqueous E. cotinifolia extract, leaves with distilled water and untreated leaves. The carrying time and leaf area consumed were determined over a five-hour period. The effect of E. cotinifolia on the development of the symbiotic fungus on three sets of five colonies fed the leaves of this plant were compared to the controls fed M. indica and oat flakes, and the effect of the addition of extracts on the culture medium used for the symbiotic fungus isolation was evaluated. Euphorbia leaf consumption was lower than that of the other diets; its consumption as the exclusive foraging resource significantly affected the symbiotic fungus, resulting in changes in colour and texture and an 83.57% decrease in volume that occasionally caused 100% mortality. Although the aqueous extract of E. cotinifolia is not a phagodeterrent for foraging workers, it is evident that E. cotinifolia is not a preferred resource for A. cephalotes due to the negative effect on the growth and viability of the symbiotic fungus.     

Allelopathic Effects of Castanea henryi Aqueous Extracts on the Growth and Physiology of Brassica pekinensis and Zea mays

The present study investigated the allelopathic effects of aqueous extracts of Castanea henryi litter on the growth and physiological responses of Brassica pekinensis and Zea mays. Treatment with high concentrations of leaf extract (0.05 g/ml for B. pekinensis and 0.10 g/ml for Z. mays) significantly increased malonaldehyde content and reduced seed germination, seedling growth, chlorophyll content, and the activity levels of antioxidant enzymes. These effects generally increased with increasing extract concentration. However, in Z. mays, low extract concentrations actually promoted seed germination, shoot growth, chlorophyll content, and antioxidant enzyme activity. The allelopathic effects of the various C. henryi extracts decreased as follows: leaf extract > twig extract > shell extract. Eleven potential allelochemicals including rutin, quercetin, luteolin, procyanidin A2, kaempferol, allantoin, propionic acid, salicylic acid, jasmonic acid, methylmalonic acid, and gentisic acid were identified in the leaves of C. henryi which were linked to the strongest allelopathic effects. These findings suggest that the allelopathic effects of C. henryi differ depending on receptor plant species, and that leaves are the most allelopathic litter in C. henryi.     

Effect of Aloe vera whole leaf extract on short chain fatty acids production by Bacteroides fragilis, Bifidobacterium infantis and Eubacterium limosum

Aims: To investigate the effect of Aloe vera whole leaf extract on pure and mixed human gut bacterial cultures by assessing the bacterial growth and changes in the production of short chain fatty acids. Methods and Results: Bacteroides fragilis, Bifidobacterium infantis, and Eubacterium limosum were incubated with Aloe vera extracts [0%, 0·5%, 1%, 1·5% and 2%; (w/v)] for 24 and 48 h. Short chain fatty acids production was measured by gas chromatography/mass spectrometry analyses. A significant linear increase in growth response to Aloe vera supplementation was observed at 24 h for each of the bacterial cultures; however, only B. infantis and a mixed bacterial culture showed a significant positive linear dose response in growth at 48 h. In pure bacteria cultures, a significantly enhanced dose response to Aloe vera supplementation was observed in the production of acetic acid by B. infantis at 24 h and of butyric acid by E. limosum at 24 and 48 h. In the mixed bacterial culture, the production of propionic acid was reduced significantly at 24 and 48 h in a dose‐dependent fashion, whereas butyric acid production showed a significant linear increase. Conclusions: The results indicated that Aloe vera possessed bacteriogenic activity in vitro and altered the production of acetic, butyric and propionic acids by micro‐organisms selected for the study. Significance and Impact of the Study: The results of the study suggest that consumption of a dietary supplement, Aloe vera, may alter the production of short chain fatty acids by human intestinal microflora.     

Phytochemical evaluation and in vitro antifungal activities of Melaleuca styphelioides leaves: comparison between volatile and non-volatile extracts

Abstract

Melaleuca styphelioides is considered as medicinal plant. This study was carried out to evaluate for the first time the phytochemical composition and to compare the antifungal activities of essential oil (EOs), methanol and aqueous extracts of M. styphelioides Sm. leaves against three fungi (Aspergillus niger, Rhizopus nigricans and Penicillium digitatum). A total of 10 components of the EO were identified, with the principal compound being methyl eugenol (87.2%). Results of the phytochemical analysis of leaves extract exhibited the presence of different phytoconstituents (phenolic compounds, flavonoids, tannins and anthocyanins). Volatile and non-volatile extracts were found to express dose-dependent inhibition against all tested fungi. Indeed, the EO oil showed significant inhibition of fungal growth and the IC₅₀ was 2.08?µL/mL for A. niger indicating that M. styphelioides leaf EO was particularly effective against this pathogen. The most susceptible species for the aqueous extract was P. digitatum (IC₅₀= 9.54?mg/mL) whereas R. nigricans was found to be more susceptible to the methanolic extract (IC₅₀= 8.31?mg/mL). Thus, the EO and aqueous as well as methanol extracts of M. styphelioides leaves possess antifungal activity and hence, it can be suggested for use in the food or pharmaceutical industries as an alternative to chemical preservatives.     

Effect of nano extracts of olea europaea leaves,ficus carica and liraglutide in lipidemic liver of type 2 diabetic rat model

The study aimed to evaluate the impact of Ficus carica mixture and Olea europaea leaf nano extracts, and liraglutide, on liver tissue and serum lipids in type 2 diabetic male albino rat model. Forty rats were divided equally into 4 groups were used. Group 1 was the non-diabetic control group. The animals in Groups 2–4 was injected intraperitoneally with a single dose of 60 mg/kg b.w. Streptozotocin to induce a diabetic rat model. Group 2 served as a positive control for diabetes. 0.02 mg/kg b.w./day of Liraglutide gave to groups 3 and 4 and 4.8 ng/ml × 10⁵ b.w./day of a mixture of the nano extracts, respectively. Eight weeks after treatment, the animals were sacrificed. Blood was collected for glucose analysis and serum low-density lipoprotein, high-density lipoprotein, total cholesterol, and triglycerides analysis, and the livers processed for histopathological examination. The elevated lipid profiles and blood glucose levels in diabetic group (Group 2) were significantly reduced (p < 0.001) following the administration of liraglutide and nano extracts in Groups 3 and 4. Progressive fatty acid changes were found in the liver sections, indicated by the deposition of various sizes of lipid droplets in most liver lobules, along with patchy hepatocyte necrosis. These pathological changes were ameliorated in the liraglutide- and nano-extract-treated rats. Treatment with the nano extracts resulted in significant power assays associated with recovery of hepatic histology and functional alterations, compared to liraglutide treatment.     

Pesticides induced oxidative stress in thymocytes

The role of oxidative stress in immune cell toxicity caused by the pesticides lindane, malathion and permethrin was investigated in thymic cells from C57BL/6 mice. Thymocytes treated with any of these pesticides (concentrations ranging between 50–150 μM) were found to generate both superoxide (^•O₂ ⁻) and H₂O₂. The production of ^•O₂ ⁻ was detected with hydroethidine-ethidium bromide assay. H₂O₂ production was monitored with a flow cytometric fluorescent (DCFH-DA) assay. All three pesticides stimulated ^•O₂ ⁻ release after 5 min exposure. Lindane and permethrin, but not malathion, continued to have significant (p ≤ 0.05) effects on ^•O₂ ⁻ generation following 15 min of exposure. The lindane + malathion mixture was found to cause more-than-additive increase in ^•O₂ ⁻ production compared to individual pesticide treatments (at both 5 and 15 min). However, the effect of the lindane + permethrin mixture was not significantly different than individual components of this mixture. The effects of these pesticides on levels of antioxidant enzymes were also investigated, and only mixtures were found to have significant (p ≤ 0.05) effects. Thus, lindane + malathion and lindane + permethrin mixtures increased total superoxide dismutase (SOD) specific activity, had no effect on catalase levels and inhibited GSH-peroxidase and GSH-reductase specific activities. Although the results of these studies do not explain the mechanism of action of these pesticides on the generation of ^•O₂ ⁻ and H₂O₂, it is worthy of note that mixtures of these chemicals have oxidative responses greater than those of single chemicals. An erratum to this article can be found at     

First report of leaf spot disease caused by Phoma eupyrena Sacc. on Aloe vera from Madhya Pradesh,India

A leaf spot disease caused by Phoma eupyrena Sacc. on Aloe vera was reported from Madhya Pradesh, India. Disease symptoms were observed as irregular to elongated, sunken lesion on both leaf surfaces which later turns creamish brown with maroon margin. The fungal colonies were whitish or light pale to dark grey colour. The pycnidia were glabrous and solitary, papillate, and indistinctly uniostiolate averages 100–260 μm in diameter. Conidia were ellipsoidal, 4.5–7.5 × 2.5–3.75 μm in size, with two large guttules. To the best of our knowledge, this is the first report of P. eupyrena causing leaf spot disease on A. vera in India.     

Evidence of Alternaria alternata Causing Leaf Spot of Aloe vera in Iran

A leaf spot and leaf blight disease was observed on Aloe vera plants as small, circular to oval dark brown necrotic sunken spots on leaves. Infected tissues collected from different sites in diseased fields were cultured on potato carrot agar medium, and the pathogen was identified as Alternaria alternata on the basis of morphological and cultural characteristics. The conidiophores were branched, straight, golden brown, smooth‐walled, measuring up to μm long by 3 μm wide with one conidial scar. The conidia were golden brown in colour and produced in long branched chains, obclavate in shape and in short conical flask. Pathogenicity tests conducted on healthy potted aloe plants in a glasshouse showed typical leaf spot symptoms after 4–7 days. The optimal temperature for the growth of A. alternata was 25°C.     

Enhanced leaf chlorophyll levels in plants treated with seaweed extract

Application to the soil of an aqueous alkaline extract ofAscophyllum nodosum resulted in higher concentrations of chlorophyll in the leaves of treated plants in comparison to control plants treated with an equivalent volume of water. Positive results were obtained with all species tested (tomato, dwarf French bean, wheat, barley, maize). When the seaweed extract was applied as a foliar spray, similar effects on leaf chlorophyll contents were obtained, except in the case of dwarf French bean plants, for which no significant difference was recorded between test and control plants. When the betaines present in the seaweed extract were applied as a mixture in the same concentrations as those in the diluted seaweed extract (-aminobutyric acid betaine 0.96 mg L^–1, -aminovaleric acid betaine 0.43 mg L^–1, glycinebetaine 0.34 mg L^–1), very similar leaf chlorophyll levels were recorded for the seaweed extract and betaine treated plants. This suggests strongly that the enhanced leaf chlorophyll content of plants treated with seaweed extract is dependent on the betaines present.     

Quantitative analysis of organophosphorus pesticides in freshwater using an optimized firefly luciferase‐based coupled bioluminescent assay

In this paper, a coupled bioluminescent assay, relying on the coupling of the enzymes acetylcholinesterase, S‐acetyl‐coenzyme A synthetase and firefly luciferase, for the detection and quantitation of organophosphorus pesticides, is presented. Using malathion as a model organophosphorus pesticide, the assay was optimized through statistical experimental design methodology, namely Plackett–Burman and central composite designs. The optimized method requires only 20 μL of sample. The linear range for the assay was 2.5–15 μM of malathion, with limits of detection and quantitation of 1.5 and 5.0 μM, respectively. This simple, fast and robust method allows samples to be analyzed at room temperature and without any pretreatment. Copyright © 2013 John Wiley & Sons, Ltd.