Showing papers on "Azadirachta published in 1993"
TL;DR: This review brings the reader up to date with both pure and applied research in the field and provides a detailed overview of present thinking into the mode of action of azadirachtin.
844 citations
TL;DR: The nonconventional effects of preparations or compounds isolated from Neem may be classified as follows: partial reduction or complete inhibition of fecundity and/or sometimes egg hatchability; reduction of the life span of adults; and direct ovicidal effects against females.
Abstract: Nonconventional insecticidal effects are exerted by preparations from the Neem tree, also called Indian lilac or Margosa tree (Azadirachta indica A. Juss, syn. Melia azadirachta L. or Antelaea azadirachta L.) (Meliaceae). A closely related species, the chinaberry tree or Persian lilac (Melia azedarch L.), is a source of substances with similar strctures and insecticidal activity. However, the seed kernels, whole fruits or leaves of many M. azedarch chemotypes contain tetranortriterpenoids and other principles highly toxic to mammals (meliatoxins). The most prominent insecticidal constituent of Neem seed kernels is the tetranortriterpenoid azadirachtin and related structures. Lesser concentrations of these active materials are found in the leaves and other parts of the tree. Third World farmers use crude Neem preparations, mainly seed kernel extracts or powders, as insecticides. An industrial Neem product, called Margosan-O, is in commercial use in the USA. The nonconventional effects of preparations or compounds isolated from Neem may be classified as follows: (i) partial reduction or complete inhibition of fecundity and/or sometimes egg hatchability; (ii) reduction of the life span of adults; (iii) oviposition repellence against females; (iv) direct ovicidal effects; (v) antifeedant effects against larvae (and nymphs) and adults; (vi) formation of permanent larvae; (vii) insect growth regulator effects at molting between larval (or nymphal) instars and especially in the prepupal stage; and (viii) analogous lesions during the emergence of adults. Phenomena (vii) and (viii) give rise to characteristic larval-pupal, nymphal-pupal, nymphal-adult and pupal-adult intermediates, and to crippled adults. © 1993 Wiley-Liss, Inc.
318 citations
TL;DR: Results indicate that the testicular effects following intra-vas application of neem oil may possibly be mediated by a local immune mechanism, and this approach to vasectomy for long-term male contraception is described.
Abstract: An alternate approach to vasectomy for long-term male contraception following a single intra-vas application of a traditional plant (Azadirachta indica) product having immunomodulatory properties is described. Male Wistar rats of proven fertility were given a single dose (50 microliters) of neem oil in the lumen of the vas deferens on each side; control animals received the same volume of peanut oil. Animals were put on continuous mating 4 weeks after the treatment, with females of proven fertility. While the control animals impregnated the female partners, all males treated with neem oil remained infertile throughout the 8 months of observation period. Epididymal and vas histology were normal without any inflammatory changes or obstruction. The intra-vas administration of neem oil resulted in a block of spermatogenesis without affecting testosterone production; the seminiferous tubules, although reduced in diameter, appeared normal and contained mostly early spermatogenic cells. No anti-sperm antibody could be detected in the serum. Unilateral administration of neem oil in the vas resulted in a significant reduction of testicular size and spermatogenic block only on the side of application; the draining lymph node cells of the treated side also showed enhanced proliferative response to in vitro mitogen challenge. These results indicate that the testicular effects following intra-vas application of neem oil may possibly be mediated by a local immune mechanism.
67 citations
TL;DR: Of 11 leaf extracts, those of A. indica and O. sanctum were most effective, and showed minimum per cent loss in fruit weight, and the appearance of the first disease symptom was also delayed in treated fruits as compared with untreated ones.
Abstract: Treatment of infested banana fruits by aqueous leaf extracts of some medicinal plants, viz. Calotropis procera (Ait) R.Br., Vitex negundo Linn., Lantana camara Linn., Azadirachta indica Linn., Ficus religiosa Linn., Ocimum sanctum Lin., Thuja orientalis Linn., Argemone mexicana Linn., Achyranthes aspera Linn., Datura fastuosa Linn. and Ricinus communis Linn. exhibited considerable control of disease development. Of 11 leaf extracts, those of A. indica and O. sanctum were most effective, and showed minimum per cent loss in fruit weight. The appearance of the first disease symptom was also delayed in treated fruits as compared with untreated ones.
56 citations
TL;DR: An aqueous extract of defatted leaves of Azadirachta indica was found to possess trypanocidal activity against Trypanosoma Brucei brucei and cured mice chronically infected with trypanosome chemotherapy.
Abstract: An aqueous extract of defatted leaves of Azadirachta indica was found to possess trypanocidal activity against Trypanosoma brucei brucei. Column chromatography of the crude extract gave three fractions, I, II, and III, that eluted with ethylacetate/methanol, benzene/methanol, and acetic acid/methanol, respectively. Of these extracts, only fraction III retained trypanocidal properties and cured mice chronically infected with Trypanosoma brucei brucei. Histopathological studies of the brains, livers, hearts, and spleens of the treated mice showed no cellular infiltrations. These findings are discussed in relation to trypanosome chemotherapy.
53 citations
TL;DR: Adverse effects of extracts from the plants Artocarpus altilis and Azadirachta indica on egg laying and hatching in the tick Boophilus microplus were quantified.
Abstract: Summary Adverse effects of extracts from the plants Artocarpus altilis and Azadirachta indica on egg laying and hatching in the tick Boophilus microplus were quantified. A 50% inhibition of egg laying was achieved by a dose of 0.54 and 0.46 μg crude ethanol extract per tick, respectively. These doses also caused a 65% and 80% hatching failure, respectively. Extracts, particularly those of A. indica, inhibit protein and lipid sequestration by ovaries and oocytes. GC-MS analyses revealed reductions in the quantities of four methyl esters sequestered from the ovaries into the oocytes oviposited on the 12th day of engorgement by the treated ticks in the order of (A. indica effects are in parentheses): undecanoic acid 10-methyl-,methyl ester 40% (100%); tetradecanoic acid, methyl ester 100% (100%); tetradecanoic acid, 12-methyl-,methyl ester 100% (100%) and pentadecanoic acid, 14-methyl-,methyl ester 30% (75%).
45 citations
Journal Article•
TL;DR: The result suggests that A.indica extract's antiinflammatory effect may be due to antagonism of the deleterious effect of 5-HT and PGE1 on blood vessels.
Abstract: Effect of Azadirachta indica (A.indica) leaf extract on inflammatory oedema induced by chemical mediators
(5-HT, histamine, bradykinin and PGE1) was studied to find out its possible mechanism of reported antiinflammatory effect against carrageenin induced rat hind paw oedema. The test material showed significant antiinflammatory effect against 5-HT and PGE1 induced inflammation but not on the inflammation induced by histamine and bradvkinin. Median effective doses of A.indica for 5-HT and PGE1 induced oedema were 1.17g and 930 mg/ kg respectively. The result suggests that A.indica extract's antiinflammatory effect may be due to antagonism of the deleterious effect of 5-HT and PGE1 on blood vessels.
40 citations
Journal Article•
38 citations
TL;DR: Leaf disk choice test bioassays demonstrated that formulated neem seed oil (NSO) was equally deterrent to first- and third-instar nymphs and adult strawberry aphids, Chaetosiphon fragaefolii (Cockerell), while NSO was deterrent to only half of the six aphid species tested.
Abstract: Leaf disk choice test bioassays demonstrated that formulated neem seed oil (NSO) was equally deterrent to first- and third-instar nymphs and adult strawberry aphids,Chaetosiphon fragaefolii (Cockerell). Concentrations of NSO resulting in 50% feeding deterrence were approximately 1.1% for this species. The rapid disruption of aphid feeding (<1 hr) was not related to the presence of the limonoid azadirachtin, and deterrence likely results from the combined activity of several compounds. Activity toC. fragaefolii disappeared within 12–24 hr following application to strawberry in the greenhouse. NSO was deterrent to only half of the six aphid species tested. The antifeedant properties of neem do not appear to contribute significantly to the control of aphids and the viruses they transmit.
33 citations
15 Jun 1993
TL;DR: Root-knot development and nematode densities decreased and plant growth responses increased with increasing concentration of the test products, and 'Nimin' was highly effective in reducing disease incidence.
Abstract: Bare-root dip treatment with 'Nimin' (contains-neem triterpenes) and some plant oils, viz., neem (Azadirachta indica), castor (Ricinus communis), rocket-salad (Eruca sativa) and mustard (Brassica juncea) showed significant inhibition of root-knot development caused by root-knot nematode Meloidogyne incognita, and population build-up of commonly occurring plant-parasitic nematodes on tomato (Lycopersicon esculentum). 'Nimin' was highly effective in reducing disease incidence. The damage caused by nematodes were recognized in terms of improved plant growth by the root-dip treatment. Root-knot development and nematode densities decreased and plant growth responses increased with increasing concentration of the test products.
32 citations
TL;DR: Media for induction of somatic embryogenesis from immature cotyledonary tissues of Azadirachta indica (Neem) were determined and Histologic studies confirmed indirect somatics embryogenesis.
Abstract: Media for induction of somatic embryogenesis from immature cotyledonary tissues ofAzadirachta indica (Neem) were determined. Callus was initiated on Murashige and Skoog medium supplemented with 0.5 mg·liter−1 of indol-3 acetic acid, 1.0 mg·liter−1 of 6-benzyl amino purine, and 1000 mg·liter−1 of casein hydrolysate. Effect of kinetin was also studied for embryo induction. Carbohydrate source in the form of sucrose and glucose alone and in combination was tested for embryogenic efficiency. Seventy percent embryos showed germination. Healthy plants were potted in sand and soil. Histologic studies confirmed indirect somatic embryogenesis.
TL;DR: Xie et al. as mentioned in this paper investigated the effects of injected AZA on Cotesia congregata (FAY) (Braconidae), a parasitoid of Manduca sexta (L).
Abstract: Azadirachtin (AZA) is the principal insecticidal compound occurring in the oil of neem [Azadirachta indica (Juss.)] seed. Although many studies have been published (Schmutterer 1990) regarding the effects of AZA on herbivorous insects, little is known of the impact of this compound on the natural enemies of herbivores. Beckage et al. (1988) investigated the effects of injected AZA on Cotesia congregata (FAY) (Braconidae), a parasitoid of Manduca sexta (L.). Parasitoid development was retarded when injections of 2.5–10 μg AZA were administered to the host larva prior to the wasp's first larval ecdysis. The development of new neem-based insecticides in North America (Isman et al. 1991) has prompted the investigation of the effects of AZA on the natural enemies of pest insects that have ingested sublethal doses of the active compound. Our laboratory study was carried out with the ichneumonid parasitoid, Diadegma terebrans (Gravenhorst), and its host, the European corn borer, Ostrinia nubilalis (Hubner). AZA (>95% purity) for this study was extracted as described previously (Xie et al. 1991) from seeds collected in India.
TL;DR: Three-generation studies indicate that NO devoid of all the bitter and odoriferous principles, may be recommended as safe for consumption by humans.
TL;DR: Crude ethanol extracts of leaves of 60 plant species belonging to 32 families and 52 genera were bioassayed for toxicity to adult Tribolium confusimi by spraying a 10% concentrate under a Potter’s tower.
Abstract: Crude ethanol extracts (CE) of leaves of 60 plant species belonging to 32 families and 52 genera were bioassayed for toxicity to adult Tribolium confusimi by spraying a 10% (w/v) concentrate under a Potter’s tower. CE of eight plants had none and three had some bioactivity; 36 CE killed from 13 to 40% of the beetles. Thirteen plant extracts inflicted between 53 and 100% mortality in the following order: Azadirachta indica (53%) < Eupatorium odorantum — Gliricida septum = Mimosa pudica (60%) < Annona reticulata = Hibiscus rosa sinensis (67%) < Cycloptis semicordata < Artocarpus altilis < Capsicum annum (90–97%) < Bontia daphnoides = Cuscuta americana = Dioscorea polygonoides = Nicotina tabacum (100%).
TL;DR: It is suggested that most of the nutrients released from the mulch were used by the plants during the same season, which increased production and could have reduced evaporation and thus increased the retention of soil water.
Abstract: From 1988 to 1990, leaves fromAzadirachta indica andAlbizia lebbeck were used as mulch on sorghum (Sorghum bicolor) in semi-arid Burkina Faso. Five different application modes, each representing a different combination of application timing and mulch composition, were evaluated. In one of the modes leaves were combined with sorghum straw. Leaf quantities applied corresponded to dosages of 25, 50 and 75 kg N ha−1 in all five modes.
TL;DR: Neem products completely prevented damage by an introduced larval population in wheat grains against larvae of Trogoderma granarium Everts and did not produce any adverse effect on nutritional composition.
Abstract: Neem (Azadirachta indica) oil and powders of neem leaf and neem kernel, citrus (Citrus limon) leaf, garlic (Allium sativum) bulb, podina (Mentha spicata) leaf were used in wheat grains at the 1 % and 2% level (w/w) against larvae of Trogoderma granarium Everts. Neem products completely prevented damage by an introduced larval population. In other treatments grain damage was noticeable after 3 months, although significantly less than in untreated grains. Thereafter, damage increased progressively and reached as high as 45% (citrus), 46% (podina) and 72% (garlic) after 6 months. Nutritional composition, viz. moisture, ash, fibre, fat, protein and carbohydrates of treated grains after 1 month, remained unaffected. After 6 months, changes in the level of nutritional compounds were proportional to insect damage. Neem products did not produce any adverse effect on nutritional composition. ‘Chapatis’ made from flour of treated grains after 1 month did not show adverse effects on colour, appearance and t...
15 Dec 1993
TL;DR: Improvement in plant growth was positively correlated with the level of nematode control and the severity of root-knot infection was greatly reduced when chopped leaves of neem and castor were incorporated into the soil.
Abstract: Root-knot development caused by Meloidogyne incognita (Kofoid et White) Chitw. on chilli (Capsicum annuum L.) cv. Jawala significantly declined in the presence of the predatory nematode Mononchus aquaticus Coetzee. The severity of root-knot infection was greatly reduced when chopped leaves of neem (Azadirachta indica A. Juss.) and castor (Ricinus communis L.) were incorporated into the soil. Improvement in plant growth was positively correlated with the level of nematode control.
TL;DR: The antifungal properties of a hydrophobic neem seed extract (clarified neem oil) were tested against three postharvest apple pathogens to investigate the use of a natural material re- ported to have antimicrobial activity.
Abstract: The antifungal properties of a hydrophobic neem (Azadirachta indica A. Juss.) seed extract (clarified neem oil) were tested against three postharvest apple (Malus domestica Borkh.) pathogens— Botrytis cinerea (pers.) ex Fr. (gray mold), Penicillium expansum Thom. (blue mold rot), and Glomerella cingulata (Ston.) Spauld. & Schrenk. (bitter rot). The antifungal activity of neem seed oil also was compared to that of CaCl 2. A 2% aqueous emulsion of the clarified neem seed oil was moderately fungicidal to B. cinerea and G. cingulata in inoculated fruit, but bad little activity against P. expansum. Ethylene production was reduced 80% in fruit dipped in 2% neem seed oil compared to wounded, inoculated controls. Neem seed oil was as effective an antifungal agent as CaCl 2, but the effects of the two combined were not additive. Recently, using fungicides to control post- harvest decay of fruit and vegetables has been restricted severely. Many compounds are be- ing removed from use, rather than undergoing the stringent tests required for re-registration. The challenge to reduce postharvest losses by means other than synthetic fungicides led us to investigate the use of a natural material re- ported to have antimicrobial activity (Kher and Chaurasia, 1977; Locke, 1986, 1990).
Journal Article•
TL;DR: A preliminary crude screening of plants in Jos Metropolis showed that at a concentration of 100 mg/l-1 the stem bark extract of the Neem plant Azadirachta indica caused a 100 percent mortality when tested against three common snail intermediate host species.
Abstract: A preliminary crude screening of plants in Jos Metropolis showed that at a concentration of 100 mg/l-1 the stem bark extract of the Neem plant Azadirachta indica caused a 100 percent mortality when tested against three common snail intermediate host species, Biomphalaria pfeifferi, Bulinus truncatus, and Lymnaea natalensis after 24 hours exposure. Toxicity test with freeze-dried aqueous extract of the plant gave 96 hours LC50 values of 19.00 mg/l-1 (p > 0.05), 10.96 mg/l-1 (p > 0.05) and 15.13 mg/l-1 (p > 0.05) against B. pfeifferi, B. truncatus and L. natalensis, respectively. When a similar test was carried out on fish, Aphyosemon giardneri a 96 hour LC50 of 15.1 mg/l-1 was recorded. Extraction with alcohol, increase in temperature within the optimal range, increase in acidity of aquatic medium and cold storage improved the potency of the extract while boiling and room storage reduced it.
01 Jan 1993
TL;DR: In a cage‐test under field conditions, 2.5 and 5 % neem seed kernel suspensions applied four times at weekly intervals to naturally infested alfalfa plants, completely interrupted the larval development of the pest and increased yield.
Abstract: Aqueous extracts of neem seed kernels and leaves, and chinaberry leaves applied to alfalfa leaves in the laboratory, caused high mortality and strong growth-disturbing effects in the larval stages of the alfalfa weevil. Most larvae died prior to or during molts. Also, an antifeedant effect was observed when alfalfa leaves treated with a 5 % aqueous neem seed kernel extract were offered to 4th-instar larvae under choice conditions. Momentary dipping of 4th-instar larvae in the same extract reduced the survival rate to 15 %. In a cage-test under field conditions, 2.5 and 5 % neem seed kernel suspensions applied four times at weekly intervals to naturally infested alfalfa plants, completely interrupted the larval development of the pest and increased yield.
Zusammenfassung
Untersuchungen zur Wirkung wasriger Extrakte von Azadirachta indica und Melia azedarach auf die Entwicklung und Mortalitat von Hypera postica Gyllenh. (Col., Curculionidae)
Wasrige Extrakte aus Samen und Blattern des Neembaumes sowie aus Blattern von Melia azedarach fuhrten bei Larven von Hypera postica zu hoher Mortalitat und deutlichen Entwicklungsstorungen. Die meisten Larven starben vor oder wahrend der Hautung. Luzerneblatter, die mit einem 5%igen wasrigen Extrakt von Neemsamen behandelt worden waren, hatten eine frasabschreckende Wirkung auf Viertlarven des Russelkafers. Eine topikale Behandlung mit derselben Konzentration fuhrte zu einer Reduktion der Uberlebensrate auf 15 %. In einem Kafigversuch unter Freilandbedingungen, bei dem wochentlich befallene Luzernepflanzen mit 2,5 und 5%igen Neemsamenextrakten behandelt wurden, konnte die Entwicklung der Kaferlarven vollstandig verhindert werden.
TL;DR: Chapatis (unleavened bread) prepared from flour of treated kernels after 1 and 6 months were of normal color, appearance, and texture, but their taste, aroma, and overall acceptability were adversely affected by insect infestation, plant products, or their combination.
Abstract: Neem (Azadirachta indica) oil and powders of neem leaf and neem kernel, citrus (Citrus limon) leaf, garlic (Allium sativum) bulb, and podina (Mentha spicata) leaf were used in maize kernels at 1 and 2% level (w/w) against larvae of Trogoderma granarium Everts. Neem kernel powder and oil provided complete protection to grains for 6 months, whereas substantial insect infestations (7-19%) were noticed after 3 months in other treatments. Infestation increased progressively and reached as high as 35 (neem leaf and podina), 43 (citrus), and 62% (garlic) after 6 months. Moisture, ash, fiber, fat, protein, and carbohydrates of treated kernels remained unaffected after 1 month of storage. After 6 months, changes in nutritional composition were proportional to insect damage. Chapatis (unleavened bread) prepared from flour of treated kernels after 1 and 6 months were of normal color, appearance, and texture, but their taste, aroma, and overall acceptability were adversely affected by insect infestation, plant products, or their combination.
TL;DR: A new isoprenylated flavanone has been isolated from the exudate of the resin glands present in shoot apices and young leaves of Azadirachta indica and characterized as 8-prenyl-5,7-dihydroxy-3′-(3,3-dimethylbutyl)-4′-methoxyflavanone on the basis of physical and spectroscopic data.
TL;DR: Neem was classified as a highly mycorrhizal‐dependent species after being transplanted into pots containing a subsurface Oxisol uninoculated or inoculated with Glomus aggregatum at three target soil solution P concentrations.
Abstract: Thirty two‐day‐old seedlings of neem (Azadirachta indica) were transplanted into pots containing a subsurface Oxisol uninoculated or inoculated with Glomus aggregatum at three target soil solution P concentrations. While no evidence of Vesicular‐arbuscular mycorrhizal fungal (VAMF) colonization was noted in the uninoculated soil, neem roots were colonized in excess of 80% in the inoculated soil, and soil P did not influence VAMF colonization significantly. VAMF colonization led to significant increases in tissue P and dry matter accumulation at the first two increments of soil P, but not at the highest concentration. Dry matter yield of mycorrhizal neem at soil P concentration of 0.02 mg L‐1 was comparable to nonmycorrhizal growth of neem at soil P concentration of 0.2 mg L‐1. Based on these data neem was classified as a highly mycorrhizal‐dependent species.
TL;DR: Above-ground and below-ground biomass and its allocation pattern in 6-year-old trees of nine species, Acacia catechu, A. catechU, Albizia lebbeck, Azadirachta indica, Dalbergia sissoo, Melia azedarach, Morus alba, Prosopis cineraria and Ziziphus mauritiana from arid north-western India were studied.
Journal Article•
TL;DR: Antifungal activity of leaf extracts of Azadirachta indica, Calotropis gigantea, Catharanthus roseus, Eucalyptus sp.
Abstract: Antifungal activity of leaf extracts of Azadirachta indica, Calotropis gigantea, Catharanthus roseus, Eucalyptus sp., Parthenium hysterophorus and Pongamia pinnata was tested against Cerotelium fici and Cercospora moricola causing leaf rust and leaf spot diseases in mulberry, respectively. A. indica was more effective inhibiting spore germination of C. fici by 91.2 per cent, whereas extracts of Eucalyptus sp. and C. gigantea proved highly toxic to C. moricola inhibiting conidial germination by 91.5 and 91.3 per cent, respectively. Under field conditions also, leaf extracts of Eucalyptus sp. and C. gigantea showed promising results reducing leaf spot disease incidence by 63.6 and 56 per cent, respectively. Extract of P. pinnata showed poor fungitoxicity against both the fungi tested.
01 Jan 1993
TL;DR: The primary intention of this overview is to concentrate primarily on one pharmacologically interesting aspect of the bioactive metabolites from tropical Meliaceae, their disrupting effect on growth, development and reproduction of insects.
Abstract: Extracts of Meliaceae, leaves, barks and especially seeds have long been used for medicinal and plant protection purposes. The Indian neem tree, Azadirachta indica A. Juss, is part of Indian folklore and one of the meliacean species which has interested several laboratories for a long time. Most of the results have been presented in three international neem conferences.1–3 The chemistry of the most intensively studied secondary metabolites from Meliaceae, i.e. the limonoids or tetranortriterpenoids, has been reviewed regularly.4–7 The primary intention of this overview is to concentrate primarily on one pharmacologically interesting aspect of the bioactive metabolites from tropical Meliaceae, their disrupting effect on growth, development and reproduction of insects.
01 Jan 1993
TL;DR: Castor and neem significantly suppressed the development of root-knot caused by Meloidogyne incognita and populations of other plantparasitic nematodes, and growth responses of tomato and chilli increased with increasing doses of additives.
Abstract: Dead fallen leaves of bakain ( Melia azedarach L.). castor ( Ricinus communis L.) and neem ( Azadirachta indica A. Juss.) significantly suppressed the development of root-knot caused by Meloidogyne incognita (Kofoid & White) Chitwood and populations of other plantparasitic nematodes. Leaves of neem were found more effective than castor and bakain. Rootknot development and nematode population densities decreased, and growth responses of tomato and chilli increased with increasing doses of additives.
01 Jan 1993
Patent•
02 Sep 1993
TL;DR: In this article, an alternative approach to vasectomy for long term male contraception following a single intra-vas.application of a traditional plant (Azadirachta indica) product having immunomodulatory properties is described.
Abstract: An alternate approach to vasectomy for long term male contraception following a single intra-vas.application of a traditional plant (Azadirachta indica) product having immunomodulatory properties is described. The intra-vas administration of neem oil to male rats resulted in a block of spermatogenesis without affecting the testosterone production; the seminiferous tubules, although reduced in diameter, appeared normal and contained mostly early spermatogenic cells. No antisperm antibody could be detected in the serum. Unilateral administration of neem oil in the vas resulted in a significant reduction of testicular size and spermatogenic block only on the side of application; the draining lymph node cells of the treated side also showed enhanced proliferative response to in vitro mitogen challenge. These results indicate that intra-vas application of neem oil is effective in blocking fertility in male mammals after a single injection.