Aqueous Extract Of Neem Research Articles

Effect of neem on Phyllocnistis citrella Stainton and its parasitoid Ageniaspis citricola Logvinovskaya in Ecuador

Efficacy of neem on Citrus Leafminer (CLM) and effect on its parasitoid Ageniaspis citricola was evaluated, using field, cage and olfactometer tests. Treatments were: aqueous extract of neem (50 gL-1), formulated oil of neem (10 mL L-1) and control. Field study was done in a Citrus aurantifolia orchard, three applications were carried out, which were evaluated every 48 hours until ten days after the treatment. Cage and olfactometer tests were performed in a greenhouse and repeated twice each time. In the cage, it were used 50 infested Citrus reticulata plants per experimental unit, while for the olfactometer test, as experimental arena, transparent plastic jars with 20 adults of CLM inside were used. Variables evaluated were: CLM infestation, dead, live and predated larvae, pupae, emerged adults and parasitized pupal chambers. The highest mortality of the CLM was caused by the aqueous extract of neem with 77.17%, which began 48 hours after application, suggesting inhibition of feeding. The aqueous extract of neem showed in average 88.80 % of repellency of adults of CLM and neem oil 85.64%. The high mortality of CLM and the repellent effect of neem, seem to influence negatively in parasitism which fluctuated between 9.45 % and 20.16 % in treated trees.

Assessment of vestibulotoxicity of neem leaf (Azadirachta indica) in a rat animal model

Introduction: Otomycosis is a challenging and frustrating entity for both patients and otolaryngologists for it frequently requires long-term treatment and follow-up, yet the recurrence rate remains high. The management is directed toward intense aural toileting with administration of topical antifungals. There has been increased resistance to classical antifungal agents, typically involving the azoles and polyenes. This has led into the research of medicinal plants as an alternative treatment for treating fungal infections. Objective: This study aims to investigate the possible vestibulotoxic effects of neem leaf (Azadirachta indica), a commonly used home remedy on the inner ear in a rat animal model. Methodology: Twenty healthy, mature Wistar albino rats were divided into three groups: Groups A (eight animals), B (eight animals), and C (four animals). They underwent baseline vestibular parameter testing, following which an endoscopic-guided transtympanic instillation of aqueous and alcohol neem extract was performed into the right middle ear of the rats in Groups A and B, while normal saline was instilled into the right middle ear of rats in Group C. Vestibular parameter testing was repeated on the rats in both groups post instillation of transtympanic neem at 4-h, 24-h, 48-h, 72-h, 1-week, 2-week, and 3-week intervals. Results: There was no deterioration in all vestibular parameters recorded post instillation of neem extract within the middle ear. Conclusion: Neem extract is a safe alternative in the treatment of otomycosis in the presence of tympanic membrane perforation as it poses no vestibulotoxic side effects.

Effects of Azadirachta Indica Leaf Extract, Capping Agents, on the Synthesis of Pure And Cu Doped ZnO-Nanoparticles: A Green Approach and Microbial Activity

AbstractThe current studies presented the green synthesis of zinc oxide and copper doped ZnO nanoparticles (NPs) using different ratios of Neem leaf extract and its antibacterial application on drug-resistant bacteria. The synthesized NPs were characterized using: X-ray diffractions (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscope (SEM), UV–visible spectroscopy and a simultaneous DTA-TGA thermal analyzer. All the synthesized materials were stable above 400°C. The powder diffraction studies indicated the formation of phase pure materials with wurtzite structure for pure ZnO and 0.5%, 1%, 1.5% Cu doped ZnO with the crystallite size in the range of 16.07 – 23.74 nm. SEM analysis revealed the formation of spherical shaped NPs with large grain size for 10% (v/v) ratio of aqueous leave extract. The aqueous extract of neem act as capping agent and prevent the NPs from agglomeration. The spectral studies confirmed the formation of NPs with the absorbance peak that is different from the micro-size ZnO. The antibacterial activities of the synthesized materials ZnO (1:1) against Staphylococcus aureus and uncalcined ZnO (7:3) and (Zn0.985Cu0.015O) against Bacillus subtilis were enhanced when referenced to the standard gentamicin.

Inhibitory Effect of Aqueous and Ethanolic Extracts of Neem Parts on Fungal Rot Disease of Solanum tuberosum.

The processing and preservation of Irish potato tubers like many other crops has been affected by various pathogens like fungi (particularly storage rot) which causes a major constraint to Irish potato production in Nigeria resulting to enormous post-harvest spoilage. The inhibitory effect of aqueous and ethanolic extracts of neem leaves, stem bark and seeds on fungal rot disease of Solanum tuberosum (Irish potato) as an alternative treatment for fungal storage disease on Irish potato tubers cultivated in Nigeria has been determined in this study. Neem parts were harvested from Wukari, Nigeria and were processed for the experiment. Isolation of fungi and sub-culturing of the isolates was carried out to obtain pure culture. Pathogenicity study was carried out and effect of the plant extracts on mycelia growth of the test fungi was studied using the food poisoning techniques. The qualitative and quantitative phytochemical studies of the neem parts were carried out using standard methods. Qualitative phytochemical screening of the selected parts of neem plant showed the presence of alkaloids, glycoside, flavonoids, carbohydrates, reducing sugar, steroids, tannins and saponins. The quantitative test revealed that the percentage quantity of phytochemicals in these plant parts ranged from 10.17-23.88%. Effect of the extracts on the test organisms was significant (p<0.05). Ethanolic extract of the seed (ESE) exhibited the highest inhibitory effect on Aspergillus niger (88.37%) followed by aqueous extract of stem bark (ABE) (87.21%), while aqueous seed extract (ASE), ethanolic leaves extract (ELE), aqueous leaves extract (ALE) and ethanolic stem bark extract (EBE) exhibited inhibition of 81.78, 77.52, 72.87 and 39.53%, respectively. The inhibitory effect of EBE was significantly (p<0.05) lower than that of other extracts, while there was no significant difference in the inhibitory effects of ESE, ASE and ABE compared to ketoconazole on Aspergillus niger. The ethanolic extracts of the seed and leaves had 100% inhibitory effect on Fusarium oxyporium with 87.60% inhibition by aqueous extract of the leaves. The seed and the leaves ethanolic extracts exhibited the highest inhibitory effects on Pythium spp. and Fusarium oxyporium, while the aqueous leaves extract showed the least inhibition on Fusarium oxyporium. The plant extracts in this study were found to be very effective in inhibiting fungal mycelia growth and hence can be potentially effective for preservation during storage of Irish potatoes to minimize post-harvest lost.

Temperature-sensitive semi-IPN composite hydrogels for antibacterial applications

This investigation aims to develop bacterial-resistant temperature-sensitive semi-IPN silver composite hydrogels via a three-step method. Primarily, the temperature-sensitive semi-IPN hydrogels of N-isopropylacrylamide and various concentrations of Pluronic F-127 (PF 127), have been prepared via a free radical polymerization technique. Furthermore, silver ions were encapsulated in the temperature-sensitive semi-IPN hydrogels via the swelling process. Finally, the bacterial-resistant semi-IPN silver composite hydrogels were developed by using an aqueous neem extract as a reducing agent. Semi-IPN hydrogels with higher amount of PF-127 showed a water uptake that was three times better than the pristine poly (N-isopropylacrylamide). The phase transition temperature of the semi-IPN silver composite hydrogels was found to be 34.24 °C, which was confirmed from the swelling and the DSC studies. The resulting hydrogels were characterized by: FTIR, UV–vis, X-ray diffraction, SEM and TEM analyses. The TEM results confirmed the fact that the nanoparticles formed were of spherical shape with a dimension of ˜8 ± 2 nm. The semi-IPN silver-composite hydrogels showed excellent bacteria inhibition against gram-positive bacteria. The results demonstrated that the temperature-sensitive semi-IPN silver-composite hydrogels developed can be employed for clinical applications.

The Insecticidal Activity of Neem (&amp;lt;i&amp;gt;Azadirachataindica&amp;lt;/i&amp;gt;) Against Weevils in Stored Bambara Nuts (&amp;lt;i&amp;gt;Vignasubterranea&amp;lt;/i&amp;gt;) and Beans (&amp;lt;i&amp;gt;Phaseolus vulgaris&amp;lt;/i&amp;gt;)

This study was undertaken to examine the insecticidal properties of Neem plant. Powder and aqueous extracts of Neem, Azadirachata indica leaves were evaluated as grain protectants against the bambara nut weevil (Callosobruchusmaculatus) and bean seed weevil (Acanthoscelidesobtectus), in the laboratory at 1.5, 2.0, and 2.5 (%v/w) concentrations per 20g of bambara nut and bean seeds respectively. Aqueous and powder extracts of Azadirachataindica leaves were applied to the bambara nut and beans seed using the contact method of application in the laboratory. Results revealed that 2.0%v/w (p=0.014) and 2.5% v/w (p=0.008) had significant increase in adult mortality of C. maculatus and A. obtectus in aqueous treatment of A. indica on beans and bambara nut after 72h at p<0.05. Similar results were obtained for beans and bambara nuts using powdered A. indica treatment. Percentage grain weight damage in bambara nut powder treatment of A. indica decreased significantly (p=0.002) at (P<0.05) in a proportionate, dose dependent manner and there was no adult emergence for either of bambara nut weevil or bean weevil. The 1.5 (%v/w) concentration was the least effective when compared with other concentrations. There was significant difference between A. indica treated grains and the control. There was no observed discoloration of the treated seeds. A. indica (aqueous and powder) extracts effectively reduced the weight loss of the treated bambara nut and seeds with 2.5% concentration being the most effective after 168hours. Phytochemical analyses of the extracts revealed presence of alkaloids, tannins, phenols, terpenes, saponins, cardiac glycosides, steroids while reducing sugars, carbohydrates and anthraquinones were absent. This study shows the insecticidal effects of A. indica against crop pests and at such there is need to further exploit Neem in order to maximize the potential. Farmers in developing countries can use A. indica as an alternative to chemical pesticide in rural grain storage.

Extrato de neem no tratamento de sementes de tomate

Os sistemas de produção orgânica devem ser implantados utilizando sementes orgânicas livres de microrganismos e sem utilizar produtos químicos. Extratos de neem têm apresentado eficiência no controle de microrganismo, porém o efeito do neem na qualidade fisiológica das sementes tratadas por ele é pouco conhecido. Objetivou-se, no presente trabalho, propor extrato aquoso de folha de neem, alternativo ao tratamento químico de semente de tomate cultivar Super Marmande. O experimento foi realizado na Universidade Estadual do Piauí campus Corrente. Produziram-se diferentes concentrações de extrato aquoso de neem utilizando 0, 40, 80, 120, 160 e 200 g de folha para cada L de água destilada. Doses de cada concentração contendo 8 ml do extrato aquoso foram utilizadas para tratar 100 sementes de tomate, além da dose de Thiran utilizando 3 gramas por quilo de semente (testemunha químico). Após tratadas as sementes foram submetidas às avaliações de germinação, primeira contagem da germinação, frio, emergência a campo, índice de velocidade de emergência, matéria seca das plântulas e índice de frequência de contaminantes. Utilizou-se o delineamento inteiramente ao acaso com 7 tratamentos em 4 repetições. Nenhuma das concentrações com extratos aquosos de folha de neem alteraram a qualidade fisiológica das sementes de tomate, porém apenas as concentrações contendo 160 e 200 g L-1 foram eficientes na redução de contaminantes presentes nas sementes. Diante dos dados obtidos recomenda-se para o tratamento orgânico de sementes de tomate utilizar extrato aquoso de neem nas concentrações entre 160 e 200 g L-1 como alternativa ao tratamento químico.

Effect of plant extracts on activity of some defense enzymes of apple fruit in interaction with Botrytis cinerea

The efficacy of seven plant extracts (neem, fennel, lavender, thyme, pennyroyal, salvia and asafetida) in controlling postharvest of apple (caused by Botrytis cinerea) was evaluated in vitro and in vivo. In vitro, all plant extracts treatments inhibited spore germination. Inhibitory rates of pore germination was 17.41 and 20.83% for neem extract treatment (methanolic and aqueous extracts, respectively) with significant difference compared to control (73.6 and 85.33%) for aqueous and methanol extracts. In the storage conditions, the application of aqueous extract of neem (at concentration of 25%) resulted in 89.11% reduction of disease severity compared with the untreated control. Results of enzymes activity showed the plant extracts can increase the activity of peroxidase, phenylalanine ammonia-lyase, β-1,3-glucanase and polyphenol oxidase in the presence of pathogens, in apple fruits. However, the results of this research revealed that application of neem extracts was more effective than the application of other plant extracts. According to this study, it could be concluded that plant extracts may be useful to control postharvest disease as a safe alternative option to chemical fungicides.

Histomorphology of testis in male mice (Musmusculus albinus) post given the aqueous seed extract of neem (Azadirachta indica A. Juss)

Neem has antispermatogenic effect in animals and male men. The objectives of this research to evaluate the effect of aqueous seed extract of neem on the structure of testis. Male mice of DDY strain were divided into five groups. Group I as a control group (C1-1) with the absence of treatment. Group II and III (s1-1 and s2-1) were orally treated by administered aqueous seeds extract of neem at doses 0.25 and 0.50 mg/kg body weight (bw) for 36 days. Group IV and V (S1-2 and S2-2) was treated by administering aqueous seeds extract of neem at doses 0.25 and 0.50 mg/kg bw for 36 days followed with another 36 days with no treatment. The results showed that neem seed extracts cause a decrease of spermatogenic cell (p < 0.05). It can be concluded that exposure to the aqueous seed extracts of neem can decrease spermatogenic cell, and its effect more than 36 days.

Antifungal effect of aqueous and ethanolic extracts of neem leaves, stem bark and seeds on fungal rot diseases of yam and cocoyam

BackgroundFungal rot diseases of white yam (Discorea rotundata) tubers and cocoyam (Colocasia esculenta) are the major post-harvest challenges in the availability of these root tubers. The use of biological extract of plants will prevent post-harvest losses without any negative health challenge.MethodsMicrowave-assisted method of extraction was used for both aqueous and ethanolic extracts of neem samples. Fungal-rotted yam and fungal-rotted cocoyam samples were collected, and fungi from them were cultured on potato dextrose agar (PDA). The same medium was used for subculturing until pure fungal isolates were obtained. Pathogenicity tests were carried out on the yam and cocoyam tubers by inoculating with isolated fungi. The neem extracts were integrated into the PDA and their antifungal effects examined.Results and discussionFrom the yam, Aspergillus ochareus, Sclerotium rolfsii and Lasidiodiplodia theobromae were isolated, while Aspergillus niger, Aspergillus oryzae and Rhizopus stolonifer were isolated from cocoyam samples. After 14 days of inoculation, isolated fungi were shown to be highly pathogenic except R. stolonifer and A. ochareus, which showed moderate pathogenicity. All the plant extracts showed antifungal activities at varied percentage mean zones of inhibition. The inhibition against fungal growth from the isolates of the rotted cocoyam gave mean inhibition between 39.53 ± 8.39% and 96.76 ± 1.60%. Except for ethanolic stem bark extract which gave 39.53 ± 8.39% limited zone of inhibition against A. niger growth, the rest of the extract exhibited good zones of inhibition against cocoyam-isolated fungi ranging between 72.87 ± 3.55 and 96.79 ± 1.60%. On fungal isolates from yam, the mean percentage zones of inhibition of all extracts of the neem plant parts showed more effectiveness than the positive control (Ketoconazole) against L. theobromae growth. Aqueous stem bark extract with 93.80 ± 1.78% zone of inhibition showed comparable effectiveness to the control (100% inhibition) against A. ochareus growth, while against S. rolfii growth, there was good inhibition by all the extracts though not to the extent as that of the control.ConclusionThe fungitoxic potential of these plant extracts on rot-inducing fungi of stored yam and cocoyam suggests that the above extracts used in this study can be put to use by farmers as alternative to commercial/synthetic fungicides.

Influence of selected legume seeds on emergence of &lt;i&gt;Callosobruchus maculatus&lt;/i&gt; (F.) and its susceptability to &lt;i&gt;Azadirachta indica &lt;/i&gt; (A. Juss) aqueous leaf extracts

In the absence of effective protection, grains of legumes may be completely decimated when attacked in storage by the cowpea bruchid, Callosobruchus maculatus . The use of botanical insecticides has been reported as ecologically innocuous alternatives to conventional insecticides for the control of C. maculatus in stored legume grains. This study thus investigated how legume type influenced the emergence of C. maculatus and its susceptibility to the aqeous extract of neem leaf (a botanical based insecticide). Thirty (30) C. maculatus adults from the same population were reared for 4 generations on improved varieties of cowpea (IT89KD391), mung bean (NM 92) and soybean (TGX 1448) seeds under laboratory conditions. While both cowpea and mung bean supported the emergence of adult C. maculatus in all the four filial generations studied, emergence in soybean terminated after first filial generation. Susceptibility of fourth filial generation adult beetles from cowpea and mung bean to neem leaves aqueous extracts was subsequently tested by contact application. Treated adult C. maculatus of the mung bean line were found to be significantly (P<0.05) more susceptible to the botanical extract than those of the cowpea line. It was thus concluded that cowpea and mung bean seeds are more suitable for the emergence of adult C. maculatus than soybean seeds and that its management in storage with neem leaves aqueous extract should be done bearing in mind that the type of legume being treated might influence the effectiveness of the botanical insecticide. Keywords : Callosobruchus maculatus , neem aqueous extracts, cowpea, mung bean, soybean.

Plant material as an alternative tool for management of aphid in country bean field

The aphids Aphis craccivora Koch attack country bean Lablab purpureus L. both in its vegetative and reproductive stages and cause severe damage. To develop an integrated management of aphid powders of black pepper, chili, turmeric, and coriander; oils of mahogany, neem, and eucalyptus; aqueous extracts of neem, basil, and garlic leaves; and water were evaluated in field conditions. The treatments were applied at 7 day intervals and aphid abundance per inflorescence was counted at 24, 48, and 72 h after treatment. All the plant materials reduced aphid abundance and flower infestation, ensuring a higher yield with larger and heavier pods. The neem oil treatment had the lowest abundance of aphid and consequently produced the highest marketable and gross yields. Predatory insects were abundant in the field, but their populations were lower in the treatments than the control. An economic analysis indicated that the highest gross return, net return, adjusted net return, and benefit-cost ratio were obtained from the mahogany oil treatment. The plant materials have insecticidal potential against aphids, and the oils of mahogany and neem showed better performances.

Farmers’ Knowledge and Perceptions of Banana Borer Weevil and Insecticidal Potential of Neem and Wood Ash for Its Management in Fako Division, Cameroon

Banana borer weevil is a major insect pest of banana and plantain in Cameroon. The undesirable effects of synthetic insecticides have attracted global attention and there is urgent need for alternative measures. This study consisted of a survey and five laboratory experiments, to investigate farmers’ perceptions of the weevil in Fako Division of Cameroon, and the insecticidal potential of the aqueous extract of neem and wood ash as alternative sources for its management. A structured questionnaire was administered in several villages in the study area. For the laboratory experiments, the treatments were the aqueous extract of neem (25, 50, 75 and 100%), wood ash (20%), mocap® (positive control) and water (negative control). Majority of the farmers (49.6%) used mocap® to control the weevil; 29.2% used at least one cultural practice, 11.2% applied wood ash while 10% employed other methods. At 14 days after exposure (DAE), the aqueous extract of neem at 75 and 100% resulted in 79% mortality of the adult weevil; 50% of the extract caused 68% mortality similar to wood ash; 25% of the extract killed 42% of them. Corms treated with water had 0% mortality throughout while those with mocap® had 100% mortality 1 DAE. The number of weevils that settled on corms treated with the extract at 50 and 75% (<1.5) and wood ash (≤1.9) was less than that on the control corms with water (≥6.2). The extract at 50 and 75% and wood ash inhibited weevil oviposition (<2 eggs laid/corm) and larva emergence (zero larva) significantly. These treatments also significantly increased the average time each larva spent locating a feeding site, initiating feeding and boring into discs compared to control discs with water. The potency of these treatments on the mortality of the weevil lasted for three to four weeks. Therefore, the aqueous extract of neem and wood ash offer a promising, affordable, environmentally friendly and cost-effective option which could be incorporated into an integrated package for sustainable management of the banana borer weevil.

Antiplasmodial activity of silver nanoparticles: A novel green synthesis approach

Objective: To synthesize silver nanoparticles using silver nitrate by a green technique which involves different compositions of aqueous leaf extracts of Azadirachta indica (neem) and Ocimum sanctum (tulsi). Methods: Their shape and size were determined using transmission electron microscopy and UV-visible spectroscopy. Their antiplasmodial activity was studied using the malarial parasite strain (Plasmodium falciparum, 3D7). The parasite strain (3D7) was collected and revived in vitro using Trager and Jensen method in RPMI 1640 medium for 7-8 cycles. Half maximal effective concentration values were calculated by nonlinear regression analysis. Results: Transmission electron microscopy results confirmed the formation of silver nanoparticles with size ranging from 4.74-39.32 nm and their size differs by varying the concentrations from 20% to 100% of neem extract in neem and tulsi extracts. It was observed that samples B and C showed half maximum effective concentration of about 0.3 μ M. Conclusions: It can be easily established that the aqueous leaf extracts of neem and tulsi in combination can be a good source for synthesis of silver nanoparticles with small size possessing appreciable antiplasmodial activity.

BIOLOGICAL ASPECTS AND INSECTICIDE ACTION OF PLANT SPECIES ON EGGS AND NYMPHS OF CITRUS BLACK FLY (Aleurocanthus woglumi Ashby - Aleyrodidae)AT LABORATORY LEVEL

ABSTRACT Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) is an important pest of many plant species in particular citrus species. The aims of this study were: (1) to observe ;'in vitro'; biological aspects in three hosts and (2) to evaluate the bioactivity of plant species on immature A.woglum. Aqueous neem extract (Meliaceae), cassava wastewater, pepper sauce and gravy peduncle floral carnation guinea button and commercial neem were used in the experiment. Egg viability (%), nymphal period duration, nymphal mortality (%), puparium stage duration and pupae viability (%) were evaluated in 50 egg positions, with minimum of five eggs in "Pera" orange, mango and malay apple leaves obtained in the field. The insecticide effect (translaminar action and direct spray) at different concentrations on immature A.woglumi was evaluated. The first bioassay conducted to evaluate the bioactivity of species by translaminar action, each sample unit corresponded to three leaves, with minimum of 20 eggs and 20 1st instar nymphs, the variables were unviable eggs and nymph mortality (%); the experiment had a completely randomized design with four replications. In the second bioassay, fully infected branches were sprayed on upper and lower face of leaves with all treatments. Leaves with at least 40 eggs and 40 1st instar nymphs were marked, and mortality (%) and emergence (%) of adults were evaluated for seven days; each sample unit was represented by 40 eggs and 40 1st instar nymphs and the experiment had a completely randomized design with four replications. The average duration of the nymphal period ranged from 7.76 to 24.18 days in 'Pera'; orange, and from 8.86 to 25.20 days in mango. There was no significant difference between the viability of eggs and nymphs in ;'Pera'; orange and mango or pupae viability between ;'Pera'; orange and malay apple. Treatment efficiency was evaluated using the Abbott's formula [E(%) = T-I/T x 100], where E ( % ) = efficiency percentage, T = number of live insects in the control treatment and I = number of live insects in treatment with insecticide. Therefore, in the first bioassay conducted to evaluate the bioactivity of species by translaminar action, all treatments showed efficiency greater than 50%. In the second bioassay by direct spraying to cassava wastewater (100% and 50 %) and commercial neem oil (1%), treatment had nymphal mortality efficiency greater than 80%.

Rationale for Water Extraction of Lipophilic Azadirachtin ( Tetranor Triterpenoid) from Neem Seeds - A Conundrum

Objectives: To extract lipophilic Azadirachtin from seed kernels of Azadirecta indica (Neem) with water and the rationale behind it as its solubility in water is very negligible (0.26 gm/lit of water).Methods: Neem seeds obtained from local market were dehulled to obtain kernels which were cold pressed to remove oil and extracted with four volumes of water at room temperature. Azadirachtin content in cold pressed neem kernel was determined using High Performance Liquid Chromatography (HPLC) with reverse phase silica column (RP18).Proteincontentinaqueousextractwasdeterminedby micro-Kjeldahl’s method and sugars by acid hydrolysis, permethylation and Gas Chromatography (GC). Findings: Aqueous extract of neem seed kernel was found to contain about 670 ppm of azadirachtin (AZA). A small portion of this aqueous extract when lyophilized yielded a hygroscopic material showing the presence of 4% AZA (HPLC method), 25% proteins (micro-Kjeldahl’s method) and about 50% of carbohydrates and other aliphatic compounds. The aqueous solution when re-extracted into ethyl acetate followed by precipitation using n-hexane yielded azadirachtin of 40% purity.Application: Lipophilic azadirachtins get extracted into water may be due to micelle formation of polysaccharides and proteins that cooccur in neem seed kernel.This hypothesis has been substantiated by addition of external azadirachtin to aqueous extract of neem seed kernel thereby enhancing its solubility from initial 670 ppm by more than two fold to a level of 1800 ppm. To obtain azadirachtin of about 40% purity directly from neem seed kernels would be possible only when first extracted with water.

Antibacterial Effect of aqueous Neem Extract on Bacterial Isolates from Mobile Phones

Now mobile phones are used for communication between different sectors of society. This study identifies the bacterial contamination of mobile phones obtained from various places of the Chennai city among the general public that are in frequent contact with each and everyone, in today’s world. A total of 10 mobile phones belonging to different areas in Chennai were screened for microorganism contamination. Mobile swab samples were collected from 10 different areas from Chennai and were dipped into 1ml sterile distilled water and spread plate method was performed to isolate the bacteria in nutrient media. Antibacterial activity of aqueous extracts of fresh neem leaves against isolated bacteria was determined by agar well diffusion method. Isolated bacterial cultures were identified by studying colony characteristics, Gram staining and Biochemical analysis based on Bergey's Manual of Determinative Bacteriology. Out of the total 10 mobile phones, Identified Organisms were Pseudomonas aeruginosa, Klebsiella pneumonia, Lactobacillus sp., Bacillussubtilis, Vibrio cholera, Escherichiacoli, Streptococcus sp., Staphylococcus sp. and Proteus vulgaris. It was found that the mobile phones of the general public were contaminated and thus acted as a potential source of various infections. Neem extract had a higher antibacterial activity of all the isolates.

Evaluation of medicinal plants and colloidal silver efficiency against Vibrio parahaemolyticus infection in Litopenaeus vannamei cultured at low salinity.

In shrimp aquaculture, reduction in the use of synthetic antibiotics is a priority due to the high incidence of resistant bacteria (Vibrio) in the white shrimp Litopenaeus vannamei. An increasing number of studies show bactericidal activity of natural treatments in aquaculture. The effectiveness of neem (Azadirachta indica) and oregano (Lippia berlandieri) aqueous extracts and colloidal silver against V. parahaemolyticus were evaluated in low salinity shrimp culture. Results show that aqueous extracts of oregano and neem each present a minimum inhibitory concentration (MIC) of 62.50 mg ml-1 and inhibitory halos of 12.0 to 19.0 mm. Colloidal silver gave a MIC of 2 mg ml-1, and the inhibitory halos were found to be between 11.8 and 18.8 mm, depending on treatment concentrations. An in vivo challenge test was conducted on white shrimp postlarvae cultured at low salinity (5 practical salinity units, PSU), and a significant increase (p < 0.05) in survival was demonstrated in the presence of the aqueous extracts (oregano 64%, neem 76% and colloidal silver 90%), when compared to the control (0%) in the challenge test. However, no significant differences were observed between treatments, suggesting that they all act as alternative bactericidal source agents against V. parahaemolyticus infections for L. vannamei postlarvae when cultured at 5 PSU.

Acute Toxicity of Neem (Azadirachta indica A. Juss) Leaf Extracts to Snake Headed Fish, Channa gachua (Ham.) with Special Reference to their Ethological Responses and Some Haematological Parameters

Objective: In the present study, acute toxicity of neem (Azadirachta indica A. Juss) leaf extracts on the freshwater unwanted fish, Channa gachua (Ham) was investigated. Materials and Methods: During the study period, ethological responses in the exposed fish (240 in number irrespective of sex) were observed. Changes in some haematological parameters like haemoglobin content (Hb), haematocrit (Ht), total erythrocyte count (TEC), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC) and blood glucose (Glu) were also measured in the exposed fish (60 in number irrespective of sex) during the acute toxicity test at different time interval. Results: The 24, 48, 72 and 96 h LC50 values for C. gachua were 21.80, 19.59, 13.95 and 11.18 g/l respectively. Toxicity factor values of this phytopiscicide to the fish were increased with the progress of exposure time. They showed an alteration in their responses with the increasing concentration of neem leaf extracts and time of exposure. A significant elevation in the level of blood glucose in the exposed fish throughout the exposure period was recorded while Hb showed significant change after 24 h and that of MCHC only at 96 h. Conclusions: The study may help to determine the toxic level of the aqueous extracts of neem leaves to the unwanted fish in aquaculture farm and to understand the mode of its action to fish behaviour and haematology. Key-words: Acute toxicity, Azadirachta indica, Snake Headed Fish, Haematological Parameters, Ethological Responses -------------------------------------------------IJLSSR----------------------------------------------INTRODUCTION Neem (Azadirachta indica A. Juss; Family: Meliaceae), a widely distributed tree in India, has been used medicinally since long back and presently emphasis has been given on its biopesticidal properties1-2. It has also been suggested as an alternative phyto-piscicide by some earlier workers3-7 Access this article online Quick Response Code: Website: www.ijlssr.com

Selected Chemical Properties, Microbial Activity and Biomass of Soils Amended with Aqueous Neem Leaf Extract

&lt;p&gt;With declining fertility levels of soils and the high cost of agricultural inputs, such as commercial fertilizers and pesticides, the use of organic inputs has increased in Zambia. While neem products have been shown to improve soil fertility status, several negative effects on soil organisms have also been cited. The negative effects have been attributed to several secondary metabolites produced by the neem plant. In Zambia, neem leaf extract is applied by small scale farmers to enhance soil fertility and promote crop productivity. This study reports the suitability of aqueous neem leaf extract as a soil amendment and its effect on soil microbial biomass and activity in local soils. Neem leaves were characterized before being used to prepare aqueous neem extract in the concentrations 2, 5, 10, 15, and 20 % in water. The extract was characterized for selected mineral components and then applied to 5 kg of soil on a weekly basis for five weeks. Each week, for ten weeks, the effect of the extract on microbial biomass and activity were determined using the Chloroform Fumigation and Incubation (CFI) and soil respiration methods, respectively. Selected soil chemical characteristics were determined at the start and end of the experiment. Results indicated that the chemical composition of the neem leaves was comparable to that observed by others and was similar to that of other tree leaves used for preparing leaf extracts. Amending soils with neem did not significantly improve selected chemical properties but only marginally increased soil calcium levels. Neem leaf extract enhanced soil microbial activity up to 10 %, but showed inhibitory effects at 15 and 20 % concentrations. Microbial biomass was also depressed by neem leaf extract at 20 %. The reduction in both microbial activity and biomass was possibly due to the negative effects of the neem secondary metabolites in the leaf extract at these higher concentrations. Although the application of neem leaf extract at 10 % percent or higher can inhibit both microbial biomass and activity, some mineralizable components in the extracts can support growth and activity of some microorganisms in the soil. Based on these results, the application of neem leaf extract at 10 % percent or higher can inhibit both microbial biomass and activity and marginally improve soil Ca levels. The use of neem leaf extract can therefore be of benefit to soils with critically low levels of Ca.&lt;/p&gt;