Showing papers on "Azadirachta published in 2003"
TL;DR: The neem seed extract at 15 microg/mL concentration was observed to be sufficient for distorting the growth pattern of the organisms tested and was found to be statistically significant with reference to the untreated fungi.
164 citations
Journal Article•
TL;DR: Most of the changes produced in this study were restored in recovery experiments.
Abstract: The effects of the ethanol extract of Azadirachta indica stem bark on body and organ weights, sperm morphology, counts and viability, serum levels of testosterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH) were studied in albino rats. Intraperitoneal administration (i.p) of the extract for ten weeks caused significant dose-dependent decreases in weights of the testis, epididymis and seminal vesicles but an increase in that of the adrenal gland. Sperm counts, morphology and viability were adversely affected in the extract treated rats. Rats that received 150 mgkg(-1) b.w. Azadirachta extract were unable to impregnate female rats throughout the duration of the study. However, these female rats conceived and sired physically normal litters about four weeks after cohabitation with untreated male rats. Azadirachta indica produced dose-dependent reduction in serum testosterone and LH but no change in FSH levels. Most of the changes produced in this study were restored in recovery experiments.
102 citations
TL;DR: The present study evaluated the effective concentration of aqueous extract of old and tender Azadirachta indica (neem) leaves to immobilize and kill 100% human spermatozoa within 20 s and found the leaf extracts to be water soluble and carbohydrate in nature.
95 citations
TL;DR: Fresh juice of tender leaves of Azadirachta indica inhibited paracetamol-induced lipid peroxidation and prevented depletion of sulfhydryl groups in liver cells, and historical observations of liver tissues corroborated these findings.
87 citations
TL;DR: Results of the two cardiac glycoside materials are comparable with those of several commercial acaricides and the risks and benefits associated with the use of cardiac Glycosides are considered.
Abstract: The cardiac glycoside, digitoxin, from Digitalis purpurea L (Scrophulariaceae), a cardiac glycosidal (cardenolide) extract from Calotropis procera (Ait) R Br (Asclepiadaceae), azadirachtin and neem oil from Azadirachta indica A Juss (Meliaceae) were tested for their effects against larvae and adult stages of the camel tick, Hyalomma dromedarii Koch (Acari: Ixodidae). The contact LC50 values of the first three materials against adults were 4.08, 9.63 and >40.7 microg cm(-2), respectively, whereas the dipping LC50 values of the four materials were 409.9, 1096, >5000 and >5000 mg litre(-1), respectively. Contact and dipping LC50 values of the extract and azadirachtin against larvae were 6.16, >20.3 microg cm(-2) and 587.7 and >2500 mg litre(-1), respectively. Azadirachtin had no effects on egg production or feeding of adults up to 5000 mg litre(-1); however at 2500 mg litre(-1), it caused significant reduction in feeding activity of larve, prolonged the period for moulting to nymphal stage, and caused 60% reduction in moultability. Results of the two cardiac glycoside materials are comparable with those of several commercial acaricides. The risks and benefits associated with the use of cardiac glycosides are considered.
85 citations
TL;DR: There are individual genetic differences among neem trees and a systematic study for tree improvement with a population of mother trees with desired traits should be undertaken by performing half-sib progeny trials and further selections by clonal propagations.
Abstract: There is a controversy over variations in azadirachtin content in neem (Azadirachta indica) seeds among various provenances and countries. Also, variations in azadirachtins are usually attributed to climatic conditions such as temperature and humidity. The present study was undertaken to evaluate qualitative and quantitative variability in azadirachtins A and B among various neem provenances or individual neem trees. Forty-three provenances of India were examined for intraprovenance variability in azadirachtin A and B content and oil percentage. Twenty-eight individual neem trees from five provenances of different agroclimatic regions were also examined for interprovenance variability. The azadirachtins were quantified using reversed phase analytical HPLC. There were wide variations in oil and azadirachtin contents among different provenances. Azadirachtin A ranged from 556.9 to 3030.8 mg kg(-)(1) of kernels, whereas azadirachtin B was in the range 43.1-590.6 mg kg(-)(1) of kernel among the provenances investigated. Analysis of variance among various neem provenances showed significant differences in oil content, azadirachtin A, total azadirachtin (A + B), and A:B ratio. There were individuals with high and low azadirachtins within a single provenance, and this trend was observed in all of the provenances selected from five agroclimatic regions of the country. Variations among individual trees of a particular provenance indicated that climatic factors such as rainfall, humidity, or temperature did not influence azadirachtin content in the neem trees. The present study shows that there are individual genetic differences among neem trees. A systematic study for tree improvement with a population of mother trees with desired traits should be undertaken by performing half-sib progeny trials and further selections by clonal propagations. The role of genetic makeup needs further research.
85 citations
TL;DR: A new tetranortriterpenoid, meliatetraolenone (1) was isolated from the methanolic extract of fresh leaves of Azadirachta indica along with the known compound odoratone (3) which was hitherto unreported from this source.
Abstract: A new tetranortriterpenoid, meliatetraolenone [24,25,26,27-tetranor-apotirucalla-(apoeupha)-6alpha-O-methyl, 7alpha-senecioyl(7-deacetyl)-11alpha,12alpha,21,23-tetrahydroxy-21,23-epoxy-2,14,20(22)-trien-1,16-dione] (1) was isolated from the methanolic extract of fresh leaves of Azadirachta indica along with the known compound odoratone (3) which was hitherto unreported from this source. Their structures have been elucidated by spectral studies including 2D NMR. The insecticidal activities of 1 as well as those of odoratone (3) are reported. 1 and odoratone both showed mortality on fourth instar larvae of mosquitoes (Anopheles stephensi) with LC(50) values of 16 and 154 ppm, respectively.
69 citations
TL;DR: Gedunin has significant in vitro activity but initially showed poor in vivo activity, and the results show the potential for both antimalarial drug and phytomedicine development from traditionally used plants.
Abstract: A quantitative ethnobotanical approach to antimalarial drug discovery led to the identification of Lansium domesticum Corr. Ser. (Meliaceae) as an important antimalarial used by Kenyah Dyak healers in Indonesian Borneo. Triterpenoid lansiolides with antimalarial activity were isolated from the bark and shown to have activity in both in vitro bioassays with Plasmodium falciparum, and in mice infected with P. berghei. A survey of African and tropical American Meliaceae led to further development of the limonoid gedunin from the traditionally used medicinal plants, tropical cedar, Cedrela odorata L., and neem, Azadirachta indica A. Juss. Gedunin has significant in vitro activity but initially showed poor in vivo activity. In vivo activity was improved by (1) incorporation into an easy to absorb suspension, (2) preparation of a more stable compound, 7-methoxygedunin; and (3) synergism with dillapiol, a cytochrome P450 3A4 inhibitor. The results show the potential for both antimalarial drug and phytomedicine development from traditionally used plants.
64 citations
TL;DR: The isolation of pure azadirachtins A, B, and H directly by MPLC purification from its concentrate and their characterization by ESIMS are unique and less time-consuming.
Abstract: Azadirachtin A enriched concentrate containing 60% active ingredient (a.i.) was prepared from the methanolic extract of the de-fatted neem (Azadirachta indica A. Juss) seed kernels. Azadirachtins A, B, and H, the three major bioactive constituents of neem seed kernel, were purified from this methanolic concentrate by employing reverse phase medium-pressure liquid chromatography (MPLC), using methanol-water solvent system as an eluant. The three pure azadirachtin congeners thus obtained were characterized by their unique mass spectral fragmentation, using electrospray probe in positive ion mode (ESI). All three azadirachtins exhibited nematicidal and antifungal activities. Azadirachtin B was the most effective against the reniform nematode Rotylenchulus reniformis (EC(50) 96.6 ppm), followed by Azadirachtin A (119.1 ppm) and H (141.2 ppm). At 200-ppm concentration, the test compounds caused 50-65% mortality of Caenorhabditis elegans nematode. Azadirachtin H showed the highest activity against the phytophagous fungi Rhizoctonia solani (EC(50) 63.7 ppm) and Sclerotium rolfsii (EC(50) 43.9 ppm), followed by B and A. The isolation of pure azadirachtins A, B, and H directly by MPLC purification from its concentrate and their characterization by ESIMS are unique and less time-consuming.
63 citations
TL;DR: The novel online monitoring of plant cell respiration activities in a new parallel shake flask measuring device suggests the necessity of a two-stage process for the production of azadirachtin-related limonoids in plant cell culture.
62 citations
Journal Article•
TL;DR: Al aqueous leaf extract significantly prevents and reverses the hepatotoxic damage induced by antitubercular drugs in rats.
Abstract: Objective: To assess the hepatoprotective activity of Azadirachta indica (AI) aqueous leaf extract on antitubercular drugs-induced hepatotoxicity in albino rats. Methods: Hepatotoxicity was induced in rats by combination of isoniazid, rifampicin and pyrazinamide given orally as suspension for 30 days. Treatment groups received Al aqueous leaf extract along with antitubercular drugs. In the second phase of study the effect of Al aqueous leaf extract on established hepatotoxicity was studied by giving the extract for 20 days after withdrawal of antitubercular drugs. Liver damage was assessed by biochemical and histological parameters. Results: Alaqueous leaf extract significantly (P<0.05) prevented changes in the serum levels of bilirubin, protein, alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. Similarly it significantly prevented the histological changes as compared to the group receiving antitubercular drugs. It also significantly reversed the biochemical and histological changes. Conclusion: Al aqueous leaf extract significantly prevents and reverses the hepatotoxic damage induced by antitubercular drugs in rats.
TL;DR: Androgenic haploids of the neem tree (Azadirachta indica A. Juss.) were produced by anther culture at the early- to late-uninucleate stage of pollen via callusing, and of the plants that regenerated from anther callus 60% were haploid,20% were diploid and 20% were aneuploid.
Abstract: Androgenic haploids of the neem tree (Azadirachta indica A. Juss.) were produced by anther culture at the early- to late-uninucleate stage of pollen. Haploid formation occurred via callusing. The best medium for inducing callusing in the anther cultures was Murashige and Skoog's basal medium (MS) (9% sucrose) supplemented with 1 μM 2,4-D, 1 μM NAA and 5 μM BAP, while anther callus multiplied best on MS medium supplemented with 1 μM 2,4-D and 10 μM Kn. These calli differentiated shoots when transferred to a medium containing BAP; 5 μM BAP was optimum for young calli (75% cultures differentiated shoots), but older calli showed the best regeneration with 7.5 μM BAP. Shoots elongated at a lower concentration of BAP—0.5 μM. These shoots were multiplied by forced axillary branching and rooted in vitro. The plants were subsequently established in soil. Of the plants that regenerated from anther callus 60% were haploid, 20% were diploid and 20% were aneuploid.
TL;DR: It is suggested that the seed oil and leaf extract of neem contain properties that could be developed and used in the control of mosquitoes in the tropics.
Abstract: The effect of crude aqueous extracts of Azadirachta indica (neem) against the larvae of Anopheles mosquito was investigated. Exposure of the larvae to undiluted extracts of seed oil, leaf and bark for 12 hours led to 100, 98, and 48% mortality, respectively. Dilution of these extracts also resulted in mortality of the larvae. We suggest that the seed oil and leaf extract of neem contain properties that could be developed and used in the control of mosquitoes in the tropics. Key words : Anopheles mosquito, neem, Azadirachta indica.
African Journal of Biotechnology Vol.2(9) 2003: 325-327
TL;DR: The antimalarial activities of the tablet suspension of the bark and leaf of Azadirachta indica were evaluated on Plasmodium yoelli nigeriensis infected mice and exhibited high prophylactic, mode‐rate suppressive and a very minimal curative schizonticidal effect.
Abstract: The antimalarial activities of the tablet suspension of the bark and leaf of Azadirachta indica were evaluated on Plasmodium yoelli nigeriensis infected mice. The tablet suspensions exhibited high prophylactic, mode-rate suppressive and a very minimal curative schizonticidal effect. No animal was cured of the infection in the curative test and there was not much increase in the survival time of the animals compared with the control. The tablet suspensions from the leaf and bark at a concentration of 800 mg/kg and chloroquine at a concentration of 62.5 mg/kg body weight produced average percentage (%) parasitaemia of 79.6%, 68.2% and 99.5% for leaf, bark and chloroquine, respectively, in chemosuppression. Also in the prophylactic treatment, the tablet suspensions at 800 mg/kg and pyrimethamine at a concentration of 0.35 mg/kg gave an average parasitaemia reduction of 75.3%, 65.6% and 98.3% for the leaf, bark and pyrimethamine, respectively.
There was a clear indication that both tablet suspensions from the leaf and bark possess antimalarial activity and a suspension from the former is relatively more effective than the bark. Extrapolation of the results from the antimalarial activity of the tablet suspension of the crude plant parts showed that an adult human would need to ingest a minimum of 48 g of the powdered plant material per day, an amount that is impracticable.
A survival index value of 0.33 was obtained with the 800 mg/kg dose level, indicating that the tablet suspension has some moderate beneficial effect. Copyright © 2003 John Wiley & Sons, Ltd.
Journal Article•
TL;DR: Present study showed that Abrollla augusta roots a nd A. il1dica leaves whe n give n togethe r as wate r cxtract had hypoglycaemi c action, which had better effect than g iven alonc.
Abstract: Combination (1:1 ) of water extract of dried powder of root and leaves (200 mg/kg body wt) of A. augusta and A. indica respectively was administered orally to alloxan diabetic rats once a day for 8 weeks. This treatment caused significant lowering of blood sugar in fasted as estimated by glucose tolerance test. The treatment resulted in a significant reduction in serum lipids. Aqueous extract also decreased the formation of lipid peroxides estimated as thiobarbituric acid reactive substance, (TBARS), and increased antioxidants (superoxide dismutase, catalase, glutathione peroxidase and glutathione transferase) in erythrocytes. There was reduction in LPO as TBARS in heart, liver, kidney, and muscles. It also prevented decrease in body weight. Present study showed that Abroma augusta roots and A. indica leaves when given together as water extract had hypoglycaemic action and had better effect than given alone.
TL;DR: In vitro screening of a number of semi-synthetic analogues of Azadirone 1 revealed that the alpha,beta-unsaturated enone moiety or its equivalent conjugated system in A-ring, C-7 acetyloxy/chloroacetyloxy or keto group in B-ring and the furan moiety are responsible for the activity of 1 and its analogues.
TL;DR: It is obvious from the present study that potentiation among non-azadirachtin limonoids having explicitly two different modes of action, such as feeding deterrence and physiological toxicity, may be playing a significant role in the potentiation effect.
Abstract: The biological activity of 6beta-hydroxygedunin isolated from Azadirachta indica A. Juss. was assessed using the gram pod borer, Helicoverpa armigera (Hubner), and Asian armyworm, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), alone and in combination with other limonoids, gedunin, salannin, nimbinene, and azadirachtin. The compound exhibited growth inhibitory activity in artificial diet bioassays, with 24.2 and 21.5 ppm, respectively, inhibiting growth by 50%. This efficacy was higher in comparison to gedunin (EC(50) = 50.8 and 40.4 ppm), salannin (EC(50) = 74.5 and 72.0 ppm), and nimbinene (EC(50) = 391.4 and 404.5 ppm). Azadirachtin, however, remained the most active neem allelochemical against both insect species. Nutritional assays clearly demonstrated that, though relative consumption and growth rates of fourth instar larvae were reduced, gedunin-type compounds induced physiological toxicity, evident by reduced efficiency of conversion of ingested food (ECI) in feeding experiments. Salannin and nimbinene, on the contrary, induced concentration-dependent feeding deterrence only. In feeding experiments, combinations of the compounds revealed that when azadirachtin was present in a mixture, EC(50) values did not deviate from the individual efficacy of azadirachtin (0.26 and 0.21 ppm, respectively) against H. armigera and S. litura larvae. However, a combination without azadirachtin did show a potentiation effect with potent EC(50) values among structurally different molecules, i.e., when salannin or nimbinene was combined with 6beta-hydroxygedunin or gedunin rather than structurally similar salannin + nimbinene or 6beta-hydroxygedunin + gedunin. Obviously, azadirachtin being the most active compound in neem is not synergized or influenced by any other limonoid, but other non-azadirachtin limonoids were more potent in specific combinations vis-a-vis the structural chemistry of the compound. It is obvious from the present study that potentiation among non-azadirachtin limonoids having explicitly two different modes of action, such as feeding deterrence and physiological toxicity, may be playing a significant role in the potentiation effect.
01 Jan 2003
TL;DR: The neem aqueous extract showed good potential to be used as a control agent for S. frugiperda and was sprayed directly on the larvae did not inhibit the larval development.
Abstract: LARVAL DEVELOPMENT AND MORTALITY OF SPODOPTERA FRUGIPERDA FED ON CORN LEAVES TREATED WITH AQUEOUS EXTRACT FROM AZADIRACHTA INDICA LEAVES The effect of aqueous extracts from neem leaves and spraying adjuvants were evaluated on development and mortality of neonate S. frugiperda larvae. Corn leaves were dipped in the aqueous extract (10 mg.mL -1 ) in the laboratory and/or sprayed in the field with a CO2 sprayer and placed in plastic cup for larvae rearing. The treated corn leaves were replaced every other day. Corn leaves submerged and sprayed with the extract caused high larval mortality (100%) and showed a negative effect on the larval development. The spreading agent and soybean oil mixed with neem extract improved larval mortality at the end of the 10-day period. The aqueous extract caused lethal effect on S. frugiperda larvae after three days of the application and sprayed directly on the larvae did not inhibit the larval development. The neem aqueous extract showed good potential to be used as a control agent for S. frugiperda.
TL;DR: Repellency was evaluated as the percentage protection against populations of mosquitoes consisting mainly of Mansonia in Gambella, western Ethiopia and the difference between pyrethrum and neem was also significant (p < 0.05).
Abstract: The repellent activity of essential oils of lemon eucalyptus (Eucalyptus maculata citrodion), rue (Ruta chalepensis), oleoresin of pyrethrum (Chrysanthemum cinerariaefolium) and neem (Azadiracta indica) have been field tested as 40%, 50% and 75% solutions in coconut oil against populations of mosquitoes consisting mainly of Mansonia in Gambella, western Ethiopia. A latin square design was used to randomize the test subjects for possible individual differences for mosquito attraction. Repellency was evaluated as the percentage protection. Deet was included in the study for comparison. All the plant products manifested repellency. At 50% concentration at which the highest repellency was recorded the protection was 91.6%, 87.0%, 96.0%, 97.9% for rue, neem, pyrethrum and deet, respectively. The essential oil of lemon eucalyptus was not tried at this concentration. At a 40% concentration deet, lemon eucalyptus and pyrethrum were significantly (p < 0.05) more effective than rue and neem. At a 50% concentration, deet and pyrethrum were significantly better (p < 0.05) than rue and neem. At a 75% concentration concentration, deet and lemon eucalypus performed significantly better (p < 0.05) than pyrethrum and neem. The difference between pyrethrum and neem was also significant (p < 0.01).
TL;DR: Bioassays carried out using artificial feed with various extract concentrations, and chlorpyrifos as control, indicated, 15 days after larvae infestation, similar efficiency in concentrations from 3.60 to 10.00 mg mL-1.
Abstract: The fall armyworm (Spodoptera frugiperda (J. E. Smith)) has been controlled with synthetic insecticides bringing risk to the environment. Neem (Azadirachta indica A. Juss) is reported to be a natural alternative to synthetic insecticides against many insect species. The objective of this work was to evaluate the activity of neem leaves aqueous extract on fall armyworm, in laboratory. Bioassays carried out using artificial feed with various extract concentrations, and chlorpyrifos as control, indicated, 15 days after larvae infestation, similar efficiency in concentrations from 3.60 to 10.00 mg mL-1. Probit analysis showed LC50 = 2.67 mg mL -1. Hence, aqueous extract from neem leaves are active against fall armyworm.
TL;DR: In this article, three groups of five indigenous male goats 5-6 months of age, were offered control concentrate mixture (Group I) and those of groups II and III were fed experimental concentrates containing 15 and 25% of water washed neem (Azadirachta indica) seed kernel cake (NKC). After 180 days of feeding the goats were slaughtered.
01 Jan 2003
TL;DR: The efficacy of aqueous extracts of leaves and twigs from six Trichilia species (T. pallens and T. pallida) against S. frugiperda was evaluated in laboratory, finding that at least one of their structures (twigs or leaves) affected the insect development.
Abstract: Spodoptera frugiperda (J.E. Smith) is the most important pest of maize. The high number of chemical applications necessary to its control has lead to some problems as resistance development and environmental contamination. The use of insecticide plants is an alternative to control this pest. The efficacy of aqueous extracts of leaves and twigs from six Trichilia species (T. casaretti, T. catigua, T. clausseni, T. elegans, T. pallens and T. pallida) against S. frugiperda was evaluated in laboratory being compared with the aqueous extract from Azadirachta indica (neem) seeds. Maize leaves immerged in each extract were dried and then given to the first instar larvae. The survival and larval weight were evaluated at the fifth day after treatment application. Concerning the six Trichilia species tested, at least one of their structures (twigs or leaves) affected the insect development. The extracts from leaves of T. pallens caused mortality similar to neem extract; the extracts from twigs of T. pallens, and twigs and leaves of T. pallida, although less efficient, also reduced the S. frugiperda larval weight and survival.
TL;DR: Immature seeds, at the early dicotyledonous stage of embryo development, is the best explant to raise endosperm callus on MS + NAA + BAP +CH (5 mumol/L) + CH (500 mg L-1).
Journal Article•
TL;DR: Evaluated extracts of neem leaves and a neem oil formulation on the control of tomato powdery mildew caused by Oidium lycopersici under greenhouse conditions demonstrated that none of the neem leaf extracts were efficient for controlling the powdery Mildew, however, the neam oil, even at the lower concentrations tested, was as effective as the fungicide normally used for the powderY mildew control.
Abstract: Carneiro, S.M. de T.P.G. Effect of neem leaf extracts and neem oil on tomato powdery mildew. Summa Phytopathologica, v.29, p.262-265, 2003. In recent years, there has been a search for alternatives to fungicides that provide satisfactory disease control with low environmental impact and low toxicity to human beings. Neem, Azadirachta indica, is a plant species with natural insecticide compounds. It has been demonstrated that the ingredients of neem are also effective in controlling some plant pathogens. The objective of this study was to evaluate the effect of extracts of neem leaves and a neem oil formulation on the control of tomato powdery mildew caused by Oidium lycopersici under greenhouse conditions. Fresh leaves were used to produce the neem leaf extract, which was evaluated at four concentrations: 2%, 4%, 8%, and 16%. A commercial neem leaf extract was also tested at the concentrations of 0,25% and 0,5%. The emulsified neem oil was evaluated at 0,25%, 0,5%, 1%, and 2%. Four experiments were carried out and the neem products were sprayed always after the appearance of the disease symptoms. The results of this work demonstrated that none of the neem leaf extracts were efficient for controlling the powdery mildew. However, the neem oil, even at the lower concentrations tested, was as effective as the fungicide normally used for the powdery mildew control.
TL;DR: Four prenylated flavanones were isolated from the methanol extract of the flowers of Azadirachta indica as potent antimutagens against Trp-P-1 in the Salmonella typhimurium TA98 assay by activity-guided fractionation.
Abstract: Four prenylated flavanones were isolated from the methanol extract of the flowers of Azadirachta indica (the neem tree) as potent antimutagens against Trp-P-1 (3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole) in the Salmonella typhimurium TA98 assay by activity-guided fractionation. Spectroscopic properties revealed that those compounds were 5,7,4‘-trihydroxy-8-prenylflavanone (1), 5,4‘-dihydroxy-7-methoxy-8-prenylflavanone (2), 5,7,4‘-trihydroxy-3‘,8-diprenylflavanone (3), and 5,7,4‘-trihydroxy-3‘,5‘-diprenylflavanone (4). All isolated compounds were found for the first time in this plant. The antimutagenic IC50 values of compounds 1−4 were 2.7 ± 0.1, 3.7 ± 0.1, 11.1 ± 0.1, and 18.6 ± 0.1 μM in the preincubation mixture, respectively. These compounds also similarly inhibited the mutagenicity of Trp-P-2 (3-amino-1-methyl-5H-pyrido[4,3-b]indole) and PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine). All of the compounds 1−4 strongly inhibited ethoxyresorufin O-dealkylation activity of cytochrome P450 1A i...
TL;DR: Efficient and highly reproducible induction of somatic embryogenesis was obtained in four out of seven selected clones of neem, Azadirachta indica A. Juss, and plantlets produced were hardy, lush green, and acclimatized casily under greenhouse conditions.
Abstract: Efficient and highly reproducible induction of somatic embryogenesis was obtained in four out of seven selected clones of neem, Azadirachta indica A. Juss. This was achieved either directly from root and nodal explants or indirectly from callus cultures initiated from leaf explants excised from 1-yr-old axenic plants. Direct induction of somatic embryogenesis was achieved both from nodal and root segments within 8 wk of culture on MS1 medium without growth regulators. However, the addition of 2.3–4.5 μM thidiazuron and 0.5 μM 2,4-dichlorophenoxyacetic acid into the medium were necessary to induce somatic embryogenesis via callus phase from leaf explants. Repetitive embryogenesis was observed within 3–4 wk following transfer of somatic embryos to a plant growth regulator-free medium. When somatic embryos of nodal and root segments were left on the induction medium without subculturing, approximately 15% of the somatic embryos developed into whole plantlets after passing through a series of developmental stages. Plantlets thus produced were hardy, lush green, and acclimatized casily under greenhouse conditions. However, somatic embryos derived from leaf explants showed low conversion rates (<5%). HPLC analysis revealed no detectable levels of azadirachtin in somatic embryos.
TL;DR: A field experiment was carried out during the rainy season (June-October) of 1998 at the Research Farm of the Indian Agricultural Research Institute, New Delhi, India to study the effect of coating prilled urea with eco-friendly neem formulations in improving the efficiency of nitrogen use in hybrid rice as mentioned in this paper.
Abstract: A field experiment was carried out during the rainy season (June-October) of 1998 at the Research Farm of the Indian Agricultural Research Institute, New Delhi, India to study the effect of coating prilled urea with eco-friendly neem (Azadirachta indica A. Juss.) formulations in improving the efficiency of nitrogen use in hybrid rice. The experiment was laid out in a split-plot design with three replications. Two rice cultivars, hybrid rice (NDHR-3) and Pusa Basmati-1, formed the main plots, with the levels of nitrogen (0, 60, 120 and 180 kg N ha-1) and various forms of urea at 120 kg N ha-1 in the sub-plots. The results obtained in this study showed that the rice hybrid NDHR-3 performed significantly better than the scented variety Pusa Basmati-1 for almost all the agronomic traits tested (growth, yield attributes, grain and straw yields, nitrogen uptake and apparent N recovery) The advantage of grain yield in hybrid NDHR-3 was nearly 16 q/ha over Pusa Basmati-1. Increasing levels of nitrogen significant...
TL;DR: Sublethal treatment of nymphs disrupted molting and caused morphological defects in adults, which indicated that neem was slow acting.
Abstract: The antifeedant activity of Neemix 4.5 EC, a commercial formulation of azadirachtin from the neem tree (Azadirachta indica A. Juss), was tested against adult Nezara viridula (L.) in the laboratory using a cowpea pod-dip method. A toxicity assay was conducted by dipping fourth-instar nymphs. Feeding by adults was significantly reduced in treated pods compared with controls, based on counts of salivary deposits on pod surfaces, inside pod walls and on seeds. The antifeedant effect of azadirachtin was significantly greater on pods treated with 5% aqueous solution than on those treated with 0.5%, indicating that the antifeedant activity was related to concentration. Bugs were initially repelled by Neemix before approaching treated pods to feed. The LC50 for nymphs was 61% (27450 ppm azadirachtin) at 2 d and ranged from 1.8 to 6.2% (810 to 2790 ppm) at 5 d post-treatment, which indicated that neem was slow acting. Sublethal treatment of nymphs disrupted molting and caused morphological defects in adults. Devel...
Journal Article•
TL;DR: The results indicated that concurrent administration of both agents resulted in a significant decrease in serum concentration, slower absorption and elimination as well as longer half-life of chloroquine sulphate.
Abstract: This study was carried out to investigate the effect of concurrent oral administration of aqueous leaf extract of Azadirachta indica (Meliaceae) on the pharmacokinetic properties of chloroquine sulphate in experimental rabbits. The results indicated that concurrent administration of both agents resulted in a significant decrease in serum concentration, slower absorption and elimination as well as longer half-life of chloroquine sulphate. The highest relative decrease of 78.0% was recorded 4 hours after concurrent administration, while the smallest decrease (64.6%) occurred 24 hours after concurrent administration. Significant reductions were also noted in some pharmacokinetic parameters of chloroquine and included the area under the curve (71.9%), maximum serum concentration (69.8%), absorption rate constant (37.3%), elimination rate constant (53.9%), clearance rate (76.5%) and volume of distribution (47.2%). However, there was a pronounced increase in the half-life of the drug (125.7%).
TL;DR: In this paper, the chemical constituents of the flowers of Azadirachta indica have led to the isolation of two new flavanones, flowerine ( 5-hydroxy-7,4-dimethoxy-8-(3-methylbut-2-enyl)flavan-4-one; 1) and flowerone ( 5,7,8, 4-tetrahydroxy-3-(3]-methyl but-3]-enyl), and two new triterpenoids, O-methylazadironolide (7
Abstract: Studies on the chemical constituents of the flowers of Azadirachta indica have led to the isolation of two new flavanones, flowerine ( 5-hydroxy-7,4-dimethoxy-8-(3-methylbut-2-enyl)flavan-4-one; 1) and flowerone ( 5,7,8,4-tetrahydroxy-3-(3-methylbut-3-enyl)flavan-4-one; 2), and two new triterpenoids, O-methylazadironolide ( 7-(acetoxy)-23-methoxy-21,23-epoxy-24,25,26,27-tetranorapotirucalla-1,14,20(22)-trien-3,21-dione; 3) and diepoxyazadirol ( (20S,23S,24R)-7--(acetoxy)-25-hydroxy-21,24 : 23,24-diepoxyapotirucalla1,14-dien-3-one; 4) along with the known triterpenoid trichilenone acetate ( 7-(acetoxy)-14,15: 21,23diepoxy-24,25,26,27-tetranorapotirucalla-1,20,22-trien-3-one; 5), two known flavanones, nimbaflavone ( 5,7dihydroxy-4-methoxy-8,3-bis(3-methylbut-2-enyl)-flavan-4-one; 6) and 3-prenylnaringenin ( 5,7,4-trihydroxy-3-(3-methylbut-2-enyl) flavan-4-one; 7), and 4-(2-hydroxyethyl)phenol (8). Their structures have been elucidated through spectral studies, including 2D-NMR experiments, and chemical transformation. Compounds 5, 7 and 8 are heretofore unreported from any part of tree, while 6 has been isolated earlier from leaves. 1. Introduction. ± Various parts of Azadirachta indica A. Juss. (syn. Melia azadirachta Linn.), a member of family Meliaceae, are highly reputed for the treatment of several human ailments, particularly for diseases of bacterial and fungal origin. Its leaves have been used in ulcer, eczema, jaundice, and liver complaints, whereas its fruits are considered purgative and emollient, useful in the treatment of intestinal worm, urinary diseases, and piles. The bark is a bitter tonic, astringent, and anti-periodontic, and dried flowers are considered tonic and stomachic [1] [2]. Although the different parts have been studied extensively for their chemical constituents [3 ± 14], systematic studies on the flowers have been lacking. Hence, the present studies undertaken on the fresh flowers of A. indica have resulted in the isolation and structure elucidation of four new and four known constituents. These include two new flavanones, flowerine (1) flowerone (2), two new triterpenoids, Omethylazadironolide (3) and diepoxyazadirol (4), the known triterpenoid trichilenone acetate (5) [15], two known flavanones, nimbaflavone (6) [16] and 3-prenylnaringenin (7) [17], and a phenolic constituent, 4-(2-hydroxyethyl)phenol (8) [18]. Flavanone 6 was reported earlier from the leaves of A. indica [16], but its presence in the flowers is hitherto unreported. Compounds 5, 7, and 8 are, until now, unreported from any part of the tree. The assignments for the 13 C-nuclei of 5 are reported for the first time.