Showing papers on "Azadirachta published in 2004"
TL;DR: The rates of reduction of the metal ions by Neem leaf extract are much faster than those observed by us in earlier studies using microorganisms such as fungi, highlighting the possibility that nanoparticle biological synthesis methodologies will achieve rates of synthesis comparable to those of chemical methods.
2,339 citations
TL;DR: The results point to the effectiveness of the Neem leaf powder as a biosorbent for removing dyes like Congo Red from water.
403 citations
TL;DR: Safe and economically cheaper uses of different parts of neem in the treatment of various diseases and in agriculture are discussed and active chemical constituents of various neem formulations are dealt with.
Abstract: Neem (Azadirachta indica A. Juss.) has universally been accepted as a wonder tree because of its diverse utility. Multidirectional therapeutic uses of neem have been known in India since the Vedic times. Besides its therapeutic efficacies, neem has already established its potential as a source of naturally occurring insecticide, pesticide and agrochemicals. Safe and economically cheaper uses of different parts of neem in the treatment of various diseases and in agriculture are discussed in this article. It further deals with the active chemical constituents of various neem formulations. Commercially available neem products are also mentioned along with their respective applications. Furthermore, evaluation of safety aspects of different parts of neem and neem compounds along with commercial formulations are also taken into consideration. Systematic scientific knowledge on neem reported so far is thus very useful for the wider interests of the world community.
268 citations
TL;DR: An adsorbent was developed from the mature leaves of the Neem tree for removing Pb(II) from water and the computation of the parameters, DeltaH, DeltaS and DeltaG, indicated the interactions to be thermodynamically favourable.
230 citations
TL;DR: In this article, the atomic absorption spectrophotometer was employed for the estimation conducted on 10 plant species collected from different locations within Ogbomoso, Ogun State, Nigeria.
216 citations
TL;DR: For all preparations, reversible effect on reproduction of both male and female mammals seem to be the most important toxic effects upon sub-acute or chronic exposure, leading to the conclusion that, if applied with care, use of neem derived pesticides as an insecticide should not be discouraged.
202 citations
TL;DR: The results of the study suggested that the dental gel containing neem extract has significantly reduced the plaque index and bacterial count than that of the control group.
188 citations
TL;DR: The findings seem very promising, suggesting that it may be possible to increase the larvicidal activity further by improving the extraction and the fractionation of the crude limonoids, for instance removing the co-extracted natural fats.
164 citations
TL;DR: Results indicate that botanical products may provide effective control of C. maculatus in cowpea and that traditionally used African plants were repellent to the beetle.
162 citations
TL;DR: Neem bark extract has therapeutic potential for controlling gastric hypersecretion and gastroesophageal and gastroduodenal ulcers and various blood parameters for organ toxicity after Neem treatment at the doses suggested remained more or less close to the normal values suggesting no significant adverse effects.
122 citations
TL;DR: Contrary to the fears that neem--a powerful nematicide--might not be palatable to the annelids, the earthworms fed voraciously on the neem compost, converting upto 7% of the feed into vermicompost per day.
TL;DR: An insecticide containing azadirachtin, a neem tree extract, was tested against mosquito larvae in the Islamic Republic of Iran under laboratory and field conditions and prevention of adult emerged and pupal mortality was the main activity of this compounds.
Abstract: An insecticide containing azadirachtin, a neem tree (Azadirachta indica) extract, was tested against mosquito larvae in the Islamic Republic of Iran under laboratory and field conditions. LC50 and LC90 values for Neemarin were 0.35 and 1.81 mg/L for Anopheles stephensi, the main local malaria vector, and 0.69 and 3.18 mg/L for Culex quinquefasciatus. The mortality in the pupal stage was significantly higher than the other stages. In field trials, using recommended dosages of 1 and 2 L/hectare, mortality of Anopheles spp. larvae was also higher than Culex spp. Prevention of adult emerged and pupal mortality was the main activity of this compounds. The maximum time of efficacy was 7 days at the highest concentration (2 L/hectare).
TL;DR: Its potential to induce only the Phase-II enzyme activity associated mainly with carcinogen detoxification in liver of mice is revealed, with a significant inhibition of tumor burden and a dose-dependent increase in extrahepatic organs.
TL;DR: The conditional tumor growth retardation, observed in mice treated with NLP before tumor inoculation, may be regulated by NLP mediated immune activation, having prominent role in the cellular immune function of the tumor host.
TL;DR: Essential oils extracted by hydrodistillation from local plants in Benin, western Africa, and oil from seeds of the neem tree were evaluated in vitro and in vivo for their efficacy against Fusarium verticillioides infection and fumonisin contamination.
Abstract: Essential oils extracted by hydrodistillation from local plants in Benin, western Africa, and oil from seeds of the neem tree (Azadirachta indica) were evaluated in vitro and in vivo for their efficacy against Fusarium verticillioides infection and fumonisin contamination. Fumonisin in corn was quantified using a fluorometer and the Vicam method. Oils from Cymbopogon citratus, Ocimum basilicum, and Ocimum gratissimum were the most effective in vitro, completely inhibiting the growth of F. verticillioides at lower concentrations over 21 days of incubation. These oils reduced the incidence of F. verticillioides in corn and totally inhibited fungal growth at concentrations of 8, 6.4, and 4.8 microL/g, respectively, over 21 days. At the concentration of 4.8 microL/g, these oils did not affect significantly fumonisin production. However, a marked reduction of fumonisin level was observed in corn stored in closed conditions. The oils adversely affected kernel germination at 4.8 microL/g and therefore cannot be recommended for controlling F. verticillioides on stored corn used as seeds, when used at this concentration. The oil of neem seeds showed no inhibitory effect but rather accelerated the growth of F. verticillioides.
TL;DR: It is suggested that the dose and greater number of allelochemicals result in the stronger allelopathic activity of neem’s bark than the leaves.
TL;DR: Neem leaf extract offers antiulcer activity by blocking acid secretion through inhibition of H+-K+-ATPase and by preventing oxidative damage and apoptosis.
Abstract: The mechanism of the antiulcer effect of Neem leaf aqueous extract to block gastric lesions in rat has been studied with emphasis on acid secretion, oxidative damage and apoptosis. The extract dose-dependently inhibits gastric lesions induced by restraint-cold stress, indomethacin and ethanol. In stress ulcer model, it is more effective than ranitidine but less effective than omeprazole. It also dose-dependently blocks pylorus ligation and mercaptomethylimidazole-induced acid secretion. In the pylorus-ligation model, it is less effective than omeprazole but as effective as ranitidine. It inhibits H+-K+-ATPase activity in vitro in concentration-dependent manner to inhibit acid secretion. Oxidative membrane damage by hydroxyl radical (*OH) as measured by lipid peroxidation in stress ulcer is significantly blocked by leaf extract. Stress-induced apoptotic DNA fragmentation is also protected. The extract also prevents *OH-mediated mucosal DNA damage in vitro by scavenging the *OH. Neem leaf extract, thus, offers antiulcer activity by blocking acid secretion through inhibition of H+-K+-ATPase and by preventing oxidative damage and apoptosis.
TL;DR: The results suggest that use of neem against pod-sucking bugs will not interfere with natural control provided by G. fulviventre and that neem extract and egg parasitoids seem to be compatible and promising control strategies for C. scutellaris.
Abstract: Extracts of neem, Azadirachta indica A. Juss, negatively affected feeding and development of Clavigralla scutellaris (Westwood), a coreid pest of pigeonpea, Cajanus cajan (L.) Millspaugh. Labial dabbing, pod wall penetration, and seed damage by fifth instars were significantly reduced on beans, Phaseolus vulgaris (L.), that had been dipped in aqueous, methanolic, or hexane extracts of neem seed kernel. When fourth instars were dipped directly into aqueous extract, developmental abnormalities of the wings occurred at all levels tested and fecundity dropped to zero at concentrations above 0.3125%. The LC50 value was 3.14% (220 ppm azadirachtin) at 8 d. The scelionid wasp Gryon fulviventre (Crawford) is an important natural enemy of Clavigralla spp.; egg mortality from this parasitoid ranged from 37 to 85% during the fall cropping season. Feeding by newly emerged wasps was dramatically reduced when honey was mixed with aqueous neem suspension, but 6-d survivorship of adults did not differ significantly from that of the control. Wasp oviposition behavior was altered slightly when coreid eggs were treated with neem: the period of antennation was significantly extended, but time for drilling, oviposition, and marking was unaffected. Neem-dipped eggs were accepted for oviposition and progeny emerged successfully from these treated eggs. Exposure of already parasitized eggs to neem did not interfere with progeny emergence, longevity, or sex ratio. Thus, neem extract and egg parasitoids seem to be compatible and promising control strategies for C. scutellaris. Our results suggest that use of neem against pod-sucking bugs will not interfere with natural control provided by G. fulviventre.
TL;DR: Two new tetracyclic triterpenoids zafaral and meliacinanhydride have been isolated from the methanolic extract of neem leaves along with two known constituents nimocinol and isomeldenin.
TL;DR: Aqueous extract of the leaves of neem was tested in vitro for antifungal activity against Penicillium expansum and fungus growth and colony characteristics, in the presence of the extract, were investigated and compared with extract‐free cultures.
Abstract: Aqueous extract of the leaves of neem [Azadirachta indica A. Juss (Meliaceae)] was tested in vitro for antifungal activity against Penicillium expansum. Patulin production was inhibited during cultivation, when concentrations higher than 50 mg/ml of neem leaf extract was added to the culture medium. Analyses of mycotoxin production were performed by TLC and HPLC. Fungal growth and colony characteristics, in the presence of the extract, were investigated and compared with extract-free cultures. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
TL;DR: O pulgao Aphis gossypii Glover (Hemiptera: Aphididae), praga prejudicial a cultura do algodoeiro, causa danos diretos, reduzindo o vigor da planta, e indiretOS, ao secretar substância doce e transmitir viroses.
Abstract: The aphid Aphis gossypii Glover (Hemiptera: Aphididae), a harmful pest on cotton, causes direct damage, reducing plant vigor, and indirect damage by honeydew secretion and transmission of several viruses. Due to the problem of pesticide resistance, alternative techniques for chemical control, such as the use of natural insecticides, have been object of research. The effects of aqueous extracts of neem (Azadirachta indica A. Juss) seed powder on the development, survival and fecundity of A. gossypii were evaluated. Treatments consisted of neem seed powder in the concentrations of 23.8, 122.0, 410.0 and 1,410.0 mg/100 mL of distilled water. Mortality rate during the nymphal development for aphids maintained on cotton leaf discs treated with the two highest concentrations were, respectively, 60.0% and 100.0%. With the exception of the highest concentration (1,410.0 mg/100 mL), neem concentrations did not extend the aphids' development period. The net reproductive rate (R0) was of 35.0 nymphs/female for control aphids and of 0.0 nymph/female when the group of females was exposed to neem seed powder at 1,410.0 mg/100 mL since birth. The aqueous extract of neem seeds is efficient against the aphid A. gossypii, causing nymph mortality and reducing their survival period and fecundity.
TL;DR: Present studies clearly demonstrate that di-n-propyl disulfide could be a potent toxicant, fumigant, and feeding deterrent for stored grain pests, if a suitable formulation and application procedure are developed.
Abstract: Head space volatiles, including 73% di-n-propyl disulfide, were collected from freshly crushed neem seeds. This compound along with previously reported diallyl disulfide (di-2-propenyl disulfide) were toxic when applied topically or as a fumigant to Tribolium castaneum adults and 8-, 12-, and 16-d-old larvae, and Sitophilus oryzae adults. Di-n-propyl disulfide significantly decreased the growth rate and dietary utilization with moderate inhibition of food consumption in both insects. The total coefficient of deterrence for this compound ranged between 68.5 and 178.6, which suggests that it has medium to very good deterrent activity vis-a-vis the treatment concentration and instar. Di-n-propyl disulfide and diallyl disulfide presented a similar effect on efficiency of conversion of ingested food, which is reduced 3-fold; this implies that both compounds are physiological toxicants. Present studies clearly demonstrate that di-n-propyl disulfide could be a potent toxicant, fumigant, and feeding deterrent for stored grain pests, if a suitable formulation and application procedure are developed.
TL;DR: The effect of different treatments of neem oil and their persistence on the oviposition behaviour and the bionomics of the noctuid Sesamia calamistis and the pyralid Eldana saccharina were tested in laboratory and greenhouse experiments.
Abstract: The effect of different treatments of neem oil (0, 0.075, 0.1 and 0.15 mL/plant) and their persistence (0, 5 and 10 days after application; DAA) on the ovi- position behaviour and the bionomics of the noctuid Sesamia calamistis and the pyralid Eldana saccharina were tested in laboratory and greenhouse experiments. 2 For most variables, no difference was found between DAA, showing that the treatments had a long-term effect, and pooled analyses across DAA were performed. Compared with the control (0 mL/plant), mean reductions due to neem in numbers of egg batch and eggs laid were 70 and 88% for S. calamistis and 50 and 49% for E. saccharina, respectively, but no differences were found among neem concentrations. 3 For both species, larval and pupal development time was shortest in the control and longest with the highest oil concentration. Immature survival, larval weight and fecundity were highest in the control and similar in the neem treatments. 4 No differences were found in sex ratios. Egg viability was highest in the control (approximately 87%) and lowest (72%) with the highest oil concentration. As a result of lower fecundity and longer developmental time, on average, the intrinsic rates of increase in the neem treatments were 30% lower than in the control. 5 In view of the low oviposition rates, immature survival, fecundity and egg viability in the neem treatments, and the relatively high persistence of neem oil, it can be expected that the reduction in densities of the two borers species in the field will be considerable.
TL;DR: Oils, both volatile and non-volatile, were easily extracted from plant material and showed promising results as a protective agent for stored cowpea.
Abstract: Traditionally used African plant powders, with a known effect against the cowpea beetle Callosobruchus maculatus in stored cowpea, were extracted with water. The extracts, 13 volatile oils, 2 non-volatile oils and 8 slurries, were evaluated for their toxic and repellent effects against the beetle. Application of volatile oils led in most cases to a reduced number of eggs on treated beans. The volatile oils of Cymbopogon nardus and C. schoenanthus caused the majority of the eggs not to develop into adult beetles. Repellent effects were found for Clausena anisata, Cymbopogon citratus, Cymbopogon nardus, a mixture of Cymbopogon citratus and Cymbopogon flexuosus, Hyptis spicigera, Tagetes minuta and for two samples of Ocimum basilicum. Non-volatile oils were not repellent and had no effect on the number of eggs laid, but the development of these eggs was hampered, most so by Azadirachta indica oil. None of the slurries had a toxic effect on the beetles, but the slurries obtained from Carica papaya, Dracaena arborea and Tephrosia vogelii were repellent, whereas the slurry from Azadirachta indica leaves was attractive. Oils, both volatile and non-volatile, were easily extracted from plant material and showed promising results as a protective agent for stored cowpea.
TL;DR: The results suggest that the stem bark extract of Azadirachta indica possesses antiulcer agents, which probably act via histamine H(2) receptor.
TL;DR: In vitro clonal propagation of a 50-year-old neem tree through axillary shoot proliferation was achieved and micropropagated plants were established in soil with >87% survival.
01 Jan 2004
TL;DR: In the past century the tree was introduced in east Africa, the Caribbean islands, Fiji, Mauritius and other areas, and it now grows in the islands of the South Pacific, the West Indies, Haiti, Surinam, the Dominican Republic, Cuba, Nicaragua and in some areas of Mexico.
Abstract: Neem, Azadirachta indica A. Juss, a versatile tree of family Meliaceae, has its origin in the forests of Karnataka (South India) or the dried island forests of Myanmar (Gamble, 1902). The subject of origin is still controversial. Roxburgh (1874) gave its origin in India when Myanmar (Burma) was a part of India. Brandis (1921) and Jacobs (1961) describe its origin in dry regions of Upper Myanmar (Irrawady valley, upper region of Prome). Its natural distribution range extends upto Shivalik hills in India (Duthie, 1903; Kanji Lal, 1928). Some authors also suggest the place of origin of neem tree in parts of South India, such as Karnataka (Troup, 1921; Vartak and Ghate, 1990). However, neem is a large-sized evergreen tree growing up to a height of 20m and a girth of 2.5m. Today neem trees are found in nearly 80 countries worldwide and global estimate is about 91 million trees. South Asian and subSaharan regions constitute the main areas of distribution. In the past century the tree was introduced in east Africa, the Caribbean islands, Fiji, Mauritius and other areas, and it now grows in the islands of the South Pacific, the West Indies, Haiti, Surinam, the Dominican Republic, Cuba, Nicaragua and in some areas of Mexico. It was introduced into selected regions of California, Southern Florida, Oklahoma, Arizona (USA) and Queensland (Australia) (Puri, 1999). At the US Department of Agriculture Experimental Station in Mayaguez, Puerto-Rico, neem trees are now 20 years old. These trees were grown from greenhouse transplants when they were close to 1m in height. In Arizona, the goal of developing a neem tree with frost resistance to –8C using seeds from Northern India was undertaken in the late 1980s (Jacobson, 1987). In South America, neem trees grow in Venezuela, Colombia,
TL;DR: The activity among nonazadirachtin limonoids in specific combination as opposed to the structural chemistry having explicitly two different modes of action, like feeding deterrence and chronic toxicity, may be playing a significant role in the multicomponent system.
Abstract: The biological activity of azadirachtin, nimbocinol, azadiradione and salannin isolated from Azadirachta indica A. Juss. (neem) was assessed alone and in combination against the cotton bollworm, Helicoverpa armigera (Hubner) and cluster caterpillar, Spodoptera litura (F) (Lepidoptera: Noctuidae). Nimbocinol exhibited growth inhibitory activity in artificial diet bioassays with 82.4 and 92.2 mg kg−1 concentrations inhibiting growth by 50%, respectively, in the two species. This efficacy was almost comparative to azadiradione (EC50 = 109.6 and 102.1 mg kg−1) and salannin (EC50 = 72.2 and 70.2 mg kg−1). Azadirachtin was the most active neem allelochemical against both insect species. In nutritional analysis, only nimbocinol and azadiradione reduced the efficiency of conversion of ingested food (ECI) in feeding experiments, indicating toxic rather than antifeedant effects. In a combination, when azadirachtin was present in a mixture, it always dominated in its efficacy and EC50 values did not deviate much from the individual efficacy of azadirachtin (0.23 and 0.21 mg kg−1, against H. armigera and S. litura larvae, respectively). However, enhanced activity among structurally variable molecules was observed, i.e., when salannin combines with nimbocinol or azadiradione, rather than structurally similar molecules like nimbocinol with azadiradione. The activity among nonazadirachtin limonoids in specific combination as opposed to the structural chemistry having explicitly two different modes of action, like feeding deterrence and chronic toxicity, may be playing a significant role in the multicomponent system.
TL;DR: Neem, Azadirachta indica, had highest phytase activity among the trees, and sewan grass, Lasiurus sindicus, resulted in more activity among grasses, which contributed significantly more than pearl millet.
TL;DR: Although this tree is a rich source of various natural products, it is the first report of identification of mono- and sesquiterpenes 26 and 21 and a potent antioxidant, 17 which are hitherto unreported previously from any part of the tree.
Abstract: As a result of chemical investigation on the ethanolic extract of fresh fruit coatings of Azadirachta indica A. Juss. (neem), twenty-seven compounds were identified in non-polar to less polar fractions which showed pesticidal activity determined by WHO method against Anopheles stephensi Liston. These identifications were basically made through GC-EIMS and were further supported by other spectroscopic techniques, including 1 3 C NMR, UV and FTIR as well as retention indices. Thus sixteen n-alkanes, 1-16; three aromatics 2,6-bis-(1,1-dimethylethyl)-4-methyl phenol (17), 2-(phenylmethylene)-octanal (20), 1,2,4-trimethoxy-5-(1Z-propenyl)-benzene (27); three benzopyranoids 3,4-dihydro-4,4,5,8-tetramethylcoumarin (18), 3,4-dihydro-4,4,7,8-tetramethylcoumarin-6-ol (19), 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta[g]-2-benzopyran (22); one sesquiterpene methyl-3,7,11-trimethyl-2E,-6E,10-dodecatrienoate (21); three esters of fatty acids methyl 14-methyl-pentadecanoate (23), ethyl hexadecanoate (24), ethyl 9Z-octadecenoate (25) and one monoterpene 3,7-dimethyl-1-octen-7-ol (26) were identified. Except 6, 8, 24 and 25 all these compounds were identified for the first time from the pericarp and fifteen of these, 1-3, 7, 9, 10, 17-23, 26, 27, are hitherto unreported previously from any part of the tree. Although this tree is a rich source of various natural products, it is the first report of identification of mono- and sesquiterpenes 26 and 21 and a potent antioxidant, 17.