Efficacy of Azadirachta indica (Neem) leaf extract and hypertonic saline solution as intratesticular chemical sterilizing agents in dogs / Eficácia do extrato de folha de Azadirachta indica (Neem) e solução salina hipertônica como agente químico esterilizante intratesticular em cães

Castration refers to induced sterility via physical, chemical, or hormonal methods. Chemical castration is an efficient and reliable technique in contrast to other sterilization procedures as it is less painful to physical methods and cost­effective to hormonal methods. Azadirachta indica (neem), is a charismatic plant as its leaves possess anti­inflammatory, anti­microbial, and anti­androgenic chattels. To abate the escalating human population in South Asia, neem oil and neem leaf extract have been effectively used as a contraceptive agent. The key determinant of the current study was to evaluate Neem as a chemical sterilizing agent, (either necrotic or apoptotic), in dogs injected intratesticular in comparison to a hypertonic saline solution. Pre­ and post­injection testicular width size and blood samples for serum testosterone levels were collected on alternative days. Results disclosed substantial changes in testicular width size, histopathological profile, and serum testosterone level. A non­significant (P > 0.05) pre­injection testicular width readings in contrast to a significant increase (P < 0.05) three days post­injection was noted in all the competitive groups. The mean values recorded for testicular width size at the end of the trial study via neem leaf extract, 30% HSS and, control groups were 27.7362 ± 2.3315mm, 30.9594 ± 4.6861mm, and 24.5023 ± 2.5387mm, respectively. A declining trend, regarding serum testosterone level being statistically significant (P < 0.05) was recorded in treated groups (A, B) in contrast to the control group (C) as the values were 1.5357 ± 0.7819ng, 1.2669 ± 0.9095ng, and 2.4517 ± 0.1827ng in groups A, B, and C, respectively. Histopathological findings advocated the presence of apoptotic bodies in the neem treated group whereas the presence of degenerated interstitial cells, necrosed seminiferous tubules, damaged germinal epithelium, and ceased spermatogenesis was also studied in both competitive groups. Thus, the apoptotic effect and anti­inflammatory property of neem leaf extract resulted in less painful castration and verified Azadirachta indica as a better substitute for chemical castration in contrast to hypertonic saline solution.(AU)

A castração consiste na indução da esterilidade por meio físico, químico ou hormonal. A castração química é uma técnica eficiente e confiável, em contraste com outros procedimentos de esterilização, pois é menos dolorosa para os métodos físicos e econômicos para os métodos hormonais. Azadirachta indica (neem), é uma planta carismática, pois possui folhas anti­inflamatórias, antimicrobianas e antiandrogênicas. Para diminuir a crescente população humana no sul da Ásia, o óleo de nim e o extrato de folhas de nim têm sido efetivamente usados como agente contraceptivo. O principal determinante deste estudo atual foi avaliar o Neem como um agente esterilizante químico (necrótico ou apoptótico) em cães injetados intratesticularmente em comparação com uma solução salina hipertônica. O tamanho da largura testicular pré e pós­injeção e as amostras de sangue para os níveis séricos de testosterona foram colhidas em dias alternados. Os resultados obtidos revelaram alterações substanciais no tamanho da largura testicular, perfil histopatológico e nível sérico de testosterona. Observou­se uma leitura não significativa (P> 0,05) da largura testicular da pré­injeção, em contraste com um aumento significativo (P <0,05) três dias após a injeção em todos os grupos competitivos.Os valores médios registrados para o tamanho da largura testicular no final do estudo via extrato de folhas de nim,HSS a 30% e grupos controle foram 27,7362 ± 2,3315 mm, 30,9594 ± 4,6861 mm e 24,5023 ± 2,5387 mm, respectivamente.Uma tendência decrescente, com relação ao nível sérico de testosterona sendo estatisticamente significante (P <0,05), foi registrada nos grupos tratados (A, B), em contraste com o grupo controle (C), pois os valores eram 1,5357 ± 0,7819ng, 1,2669 ± 0,9095ng e 2,4517 ± 0,1827ng nos grupos A, B e C, respectivamente. Os achados histopatológicos advogaram a presença de corpos apoptóticos no grupo tratado com nim, enquanto a presença de células intersticiais degeneradas, túbulos seminíferos necrosados, epitélio germinativo danificado e espermatogênese interrompida também foi estudada nos dois grupos competitivos. Assim, o efeito apoptótico e a propriedade anti­inflamatória do extrato de folhas de nim resultaram em uma castração menos dolorosa e confirmaram que a Azadirachta indica foi um melhor substituto para a castração química do que a solução salina hipertônica.(AU)

Comparative immunomodulation potential of Tinospora cordifolia (Willd.) Miers ex Hook. F., Tinospora sinensis (Lour.) Merrill and Tinospora cordifolia growing on Azadirachta indica A. Juss.

Guduchi has been widely used in the traditional medicine as an immunomodulator. Description of guduchi in Ayurvedic literature resemble with T. sinensis rather than with commonly available T. cordifolia and hence this may be used as substitutes for T. sinensis. T. cordifolia growing on Azadirachta indica commonly called Neem-guduchi has more immunomodulatory potential. Thus, immunomodulatory activity of three Tinospora spp. was assessed by checking humoral and cell mediated immune responses to the antigenic challenges with sheep RBCs and by neutrophil adhesion tests on albino Wistar rats using Guduchi-Satwa, a well known dosage form. Results revealed that Neem-guduchi possesses higher immunomodulatory potential at the dose of 300 mg/kg, po and validated the traditional claim. Hence, Neem-Guduchi can be employed in immunomodulatory formulation prepared using guduchi.

Cumulative mortality of Aedes aegypti larvae treated with compounds / Mortalidade acumulativa de larvas de Aedes aegypti tratadas com compostos

OBJECTIVE To evaluate the larvicidal activity of Azadirachta indica, Melaleuca alternifolia, carapa guianensis essential oils and fermented extract of Carica papaya against Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). METHODS The larvicide test was performed in triplicate with 300 larvae for each experimental group using the third larval stage, which were exposed for 24h. The groups were: positive control with industrial larvicide (BTI) in concentrations of 0.37 ppm (PC1) and 0.06 ppm (PC2); treated with compounds of essential oils and fermented extract, 50.0% concentration (G1); treated with compounds of essential oils and fermented extract, 25.0% concentration (G2); treated with compounds of essential oils and fermented extract, 12.5% concentration (G3); and negative control group using water (NC1) and using dimethyl (NC2). The larvae were monitored every 60 min using direct visualization. RESULTS No mortality occurred in experimental groups NC1 and NC2 in the 24h exposure period, whereas there was 100% mortality in the PC1 and PC2 groups compared to NC1 and NC2. Mortality rates of 65.0%, 50.0% and 78.0% were observed in the groups G1, G2 and G3 respectively, compared with NC1 and NC2. CONCLUSIONS The association between three essential oils from Azadirachta indica, Melaleuca alternifolia, Carapa guianensis and fermented extract of Carica papaya was efficient at all concentrations. Therefore, it can be used in Aedes aegypti Liverpool third larvae stage control programs. .

OBJETIVO Avaliar a eficácia de composto de óleos essenciais de Azadirachta indica, Melaleuca alternifolia, Carapa guianensis e extrato fermentado de Carica papaya sobre larvas de Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). MÉTODOS O ensaio larvicida foi realizado em triplicata com 300 larvas para cada grupo experimental utilizando larvas de terceiro estádio, as quais foram expostas por 24h, em 2013. Os grupos foram: controles positivos com larvicida industrial (BTI) nas concentrações de 0,37 ppm (CP1) e 0,06 ppm (CP2); tratado com composto de óleos essenciais e extrato fermentado na concentração de 50,0% (G1); tratado composto e óleos essenciais e extrato fermentado na concentração de 25,0% (G2); tratado com composto de óleos essenciais e um extrato fermentado na concentração de 12,5% (G3); controle negativo com água (CN1) e controle dimetil sulfóxido (CN2). As larvas foram monitoradas a cada 60 min através de visualização direta. RESULTADOS Larvas dos grupos CN1 e CN2 não tiveram mortalidade durante o período de 24h de exposição, mas os grupos CP1 e CP2 apresentaram taxa de mortalidade de 100% em relação a CN1 e CN2. Os tratamentos G1, G2 e G3 exerceram atividade larvicida de 65,0%, 50,0% e 78,0%, respectivamente, quando comparados a CN1 e CN2. CONCLUSÕES A associação entre os três óleos essenciais de Azadirachta indica, Melaleuca alternifolia, Carapa guianensis e extrato fermentado de Carica papaya foi eficiente em todas as concentrações testadas, podendo ser utilizado no controle de larvas de terceiro estádio de A. aegypti linhagem Liverpool. .

Azadirachta indica mitigates DMBA-induced hepatotoxicity: A biochemical and radiometric study.

The hepatoprotective potential of aqueous Azadirachta indica leaf extract (AAILE) was assessed against DMBA-induced hepatotoxicity. DMBA  (7,12-dimethylbenz[a] anthracene) treatment (40 mg/kg body weight, ip) to male Balb/c mice resulted in the derailment of liver function as revealed by extremely slow clearance of 99mTc-mebrofenin from liver, elevated levels of alkaline phosphatase (ALP) and alanine transaminase (ALT), compared to control group. In addition, elevated micronuclei score and high apoptotic index indicated hepatogenotoxicity in DMBA-treated mice. DMBA treatment also upregulated cytochrome P450 (CYP), cytochrome b5 (Cyt b5) and decreased glutathione-S-transferase activity in hepatic tissue, compared to control group. Enhanced lipid peroxidation (LPO) levels along with decreased reduced glutathione (GSH) level were also observed in DMBA group, compared to control group. AAILE co-treatment (200 mg/kg body weight, po, thrice a week) for 8 weeks followed by DMBA injection showed significant improvement in hepatic status, as revealed by normalization of 99mTc-mebrofenin clearance rate, decreased ALP and ALT levels, reduced genotoxicity in terms of micronuclei score and apoptotic index. Levels of LPO were significantly decreased along with increased hepatic GST and GSH levels in AAILE + DMBA group, compared to DMBA group. However, no significant change was observed in hepatic CYP and Cyt b5 levels, compared to DMBA group. The results indicated that AAILE effectively ameliorated DMBA-induced hepatotoxicity.

Screening the antifungal activity of essential oils against decay fungi from palmyrah leaf handicrafts

BACKGROUND: The whitish tender leaves of Palmyrah are used for making handicrafts. The problem with these articles is discolouration with time and become more brittle due to fungal attack. This could be prevented by some protective coating. Instead of expensive and harmful chemicals we decided to test natural plant essential oils to control fungal attack. Palmyrah leaf article decay fungi were isolated from two different sites of Jaffna peninsula. In this investigation Antifungal Activity of different plant essential oils from neem (Azadirachta indica), castor (Ricinus communis), citronella (Cymbopogon sp) and camphor (Cinnamomum camphora) obtained from local market have been evaluated against isolated fungi. For screening of Antifungal activity, tests and controls were set to determine minimum inhibitory concentration (MIC) and Percentage of Growth Inhibition. RESULTS: Morphologically three different types of Palmyrah leaf decay fungi were isolated and characterized asAspergillus niger, Aspergillus flavus and Penicillium sp. Neem and castor oils have recorded no significant (0.05 > P) antifungal activity while citronella and camphor oils showed significantly different antifungal activity compared with control. Camphor oil and Citronella oil showed 100, 58.13% of average growth inhibition for A. niger. 96.38, 51.32% for A.flavus and 84.99, 72.76% forPenicillium sp respectively. Camphor oil showed highest percentage of growth inhibition at lowest minimum inhibitory concentration compared with citronella oil. Camphor oil was found to be highly antifungal and most effective against A niger, and A. flavus, compared with Penicillium sp and gave 100 percentage of growth inhibitions at 5, 1 and 15 ml/dl minimum inhibitory concentration respectively. CONCLUSION: Significantly higher broad-spectrum of antifungal activity was observed in camphor oil than other tested oils because it showed highest percentage of growth inhibition at lowest inhibitory concentration. Therefore it could be used for the development of new environmental friendly antifungal agent for the preservation of leafy handicrafts. Further formulation, field experiments are necessary to achieve this target.

Effect of natural gel product on bovine dentin erosion in vitro

Objective: To evaluate the efficacy of Neem (Azadirachta indica) experimental gel for the prevention of erosive wear on bovine dentin, in vitro. Material and Methods: One hundred dentin blocks were allocated into 5 experimental groups (20 samples each): C (control group, without gel); CG (control group, only base gel); F (fluoride gel, 1.23% NaF; pH 4.1, Dentsply; Brazil); N (Neem gel, 10% neem extract; pH 4.1, manipulation); NF (Neem+fluoride gel, 10% Neem extract and 1.23% NaF; pH 4.1, manipulation). The blocks were stored in artificial saliva for 24 hours. After this, they were submitted to six alternating re- and demineralization cycles. The blocks were analyzed for wear (profilometry). The results were submitted to statistical analysis by ANOVA and Tukey tests (P<0.05). Results: The mean wear (±SD, µm) was shown as follows in groups: C (13.09±0.99), CG (10.60±1.99), F (10.90±1.44), N (12.68±1.13) and NF (10.84±1.65). All gels showed some preventive action when compared with control group. However, significant differences were found only between Neem+fluoride gel and fluoride gel. Conclusion: A single application of a neem-containing fluoride gel reduced dentin erosion, thus it is a possible alternative in reducing dental wear. Further research should investigate the action mechanism and the synergism between them. .

Modulatory effects of Azadirachta indica leaf extract on cutaneous and hepatic biochemical status during promotion phase of DMBA/TPA-induced skin tumorigenesis in mice.

The modulation in biochemical status of skin and hepatic tissue at the time point of commencement of promotion stage of skin carcinogenesis in mice and its intervention with aqueous Azadirachta indica leaf extract (AAILE) were investigated. 7,12-Dimethylbenz(a)anthracene (DMBA, 500 nmol/100 ul of acetone) was applied topically for 2 weeks (twice weekly), followed by phorbol-12-myristate-13-acetate (TPA, 1.7 nmol/100 ul) twice weekly for 6 weeks on the depilated skin of mice and AAILE was administered orally at a dose level of 300 mg/kg body wt thrice a week for 10 weeks. DMBA/TPA treatment upregulated the phase I enzymes in skin and hepatic tissue, as revealed by the increased cytochrome P450 (CYP) and cytochrome b5 (cyt b5) levels and aryl hydrocarbon hydroxylase (AHH) activity when compared to the control group and differentially modulated the activities of phase II enzymes like glutathione-s-transferase (GST), DT-diaphorase (DTD) and uridine diphosphate glucuronosyltransferase (UDP-GT). AAILE treatment decreased the DMBA/TPA-induced increase in cutaneous CYP level and enhanced the DTD and UDP-GT activities when compared with DMBA/TPA group. In the hepatic tissue of AAILE + DMBA/TPA group, an increase in UDP-GT activity was observed when compared to DMBA/TPA group. DMBA/TPA treatment did not alter the skin lipid peroxidation (LPO) level when compared to control group, however, in the animals that received AAILE treatment along with DMBA/TPA, a significant increase in LPO was observed when compared to control group. This was associated with a decrease in cutaneous reduced glutathione (GSH) level of AAILE + DMBA/TPA group. Enhanced LPO level was observed in the hepatic tissue of DMBA/TPA and AAILE + DMBA/TPA groups when compared to control group. However, no alteration was observed in their hepatic GSH levels. The micronuclei score in hepatic tissue did not exhibit significant inter-group differences. The results of the present study suggest that apart from skin, liver may be affected during DMBA/TPA-induced skin tumorigenesis. AAILE treatment has the ability to modulate these changes potentially influencing the process of tumor formation. These findings seem to be important to carcinogenesis and its intervention with anti-cancer agents.

The cytotoxic and antileishmanial activity of extracts and fractions of leaves and fruits of Azadirachta indica (A Juss.)

The leishmaniases are severe parasitic diseases that occur worldwide, caused by protozoa of the genus Leishmania. Studies with medicinal plants can lead to a range of possibilities for treating and improving the patients' quality of life. Research on Azadirachta indica fractions and extracts has shown that they have excellent anti-leishmanial activity based on bioactivity-guided fractionation of ethanolic extracts of leaves and seeds and in vitro activity against promastigotes. In this research the most efficient extracts and fractions were selected for tests on intracellular amastigotes of Leishmania amazonensis. The ethanolic extract of the leaves and dichloromethane and chloroform fractions had IC50 values of 38, 3.9 and 1.2 μg/mL for promastigotes and 9.8, 1.1 and 0.6 μg/mL for amastigotes, respectively, at 72 hours. For the ethanolic extract and dichloromethane fraction from nut tegument, the IC50 was 2.7 and 2.1 μg/mL for promastigotes and 0.4 and 0.6 μg/mL for amastigotes. The cytotoxicity of the fractions presented selectivity that was between 8 to 32 times more toxic to promastigotes and 15 to 72 times to amastigotes than to macrophages. The extracts and fractions from leaves and fruits were more effective against amastigotes, and the fractionation increased activity against both promastigotes and amastigotes, enabling us to obtain potentially active fractions with low toxicity.

Efeito do nim (Azadirachta indica) na mosca-das-frutas Ceratitis capitata (Diptera: Tephritidae) e seu parasitoide Diachasmimorpha longicaudata (Hymenoptera: Braconidae) / Effect of neem (Azadirachta indica) oil on the fruit-fly Ceratitis capitata (Diptera: Tephritidae) and its parasitoid Diachasmimorpha longicaudata (Hymenoptera: Braconidae)

Este trabalho teve como objetivo avaliar a ação do inseticida botânico nim em larvas de Ceratitis capitata, bem como no parasitismo destas larvas por Diachasmimorpha longicaudata. Para tanto, larvas de 3o ínstar de C. capitata foram mergulhadas por 30 segundos em soluções contendo as concentrações de 0,5%, 1% e 1,5% de um produto comercial à base de óleo de nim a 0,37% (3.686 ppm), além da testemunha mergulhada apenas em água destilada. Em seguida, as larvas foram expostas ao parasitismo de D. longicaudata por um período de 2 horas e 30 minutos. No experimento sem chance de escolha, para cada tratamento, uma única "unidade de parasitismo" foi pendurada no interior da gaiola. No experimento com livre escolha, as "unidades de parasitismo" foram penduradas no interior de uma mesma gaiola, de forma que os parasitoides tivessem livre acesso a todos os tratamentos. No experimento sem livre escolha, foi constatado que o aumento da concentração de nim diminuiu a atração das fêmeas, o número de fêmeas que efetuaram postura, o índice de parasitismo e a emergência dos parasitoides. No experimento com livre escolha, verificou-se que a emergência dos parasitoides e o índice de parasitismo também foram prejudicados nas maiores concentrações de nim. A ação isolada do nim, quando em contato com as larvas de 3o instar, não afetou a emergência de C. capitata.

The purpose of this work was to evaluate the action of the botanic insecticide neem oil on larvae of Ceratitis capitata, as well as in the parasitism of these larvae by Diachasmimorpha longicaudata. Third-instar larvae were immersed for 30 seconds in a neem solution, in concentrations of 0.5%, 1% and 1.5% of a commercial product composed of 0.37% (3.686 ppm) neem oil, while the controls were immersed only in distilled water. Soon afterwards the larvae were exposed to parasitism of D. longicaudata for 2 hours and 30 minutes. In the no-choice experiment, for every treatment, a single "parasitism unit" was hung inside the cage. In the experiment with free choice, "parasitism units" were hung inside another cage, so that the parasitoids had free access to all treatments. In the no-choice experiment, it was ascertained that the increase of the neem oil concentration decreased the attraction of the females, the number of females that lay, the parasitism rate and parasitoid emergency. In the experiment with free choice, it was ascertained that the emergence of parasitoids and parasitism rate were harmed at the larger neem oil concentrations. The isolated action of neem oil, when in contact with the third-instar larvae, did not affect the emergence of C. capitata.

Larvicidal & emergence inhibitory activities of NeemAzal T/S 1.2 per cent EC against vectors of malaria, filariasis & dengue.

Background & objectives: Vector control, using agents of chemical origin, continues to be practiced in the control of vector borne diseases. However, due to some drawbacks including lack of selectivity, environmental contamination, and emergence and spread of vector resistance, development of natural products for vector control has been a priority in this area. In the present study we evaluated the larvicidal and emergence inhibitory activities of a neem based formulation Neem Azal T/S 1.2 per cent EC against the vectors of malaria, filariasis and dengue. Method: Larvicidal and emergence inhibition (EI) activity of a neem formulation, NeemAzal T/S 1.2 per cent EC, was studied in the laboratory respectively against early 4th and early 3rd instar larvae of Anopheles stephensi, Culex quinquefasciatus and Aedes aegypti following standard procedures. Results: Among the three vector species studied, An. stephensi was highly susceptible to NeemAzal T/S as revealed by the LC50 and LC90 values (1.92 and 2.76 ppm). The formulation produced an overall mortality or inhibition of emergence of 90 per cent (EI90, when 3rd instar larvae were treated) at 0.046, 0.208 and 0.866 ppm in An. stephensi, Cx. quinquefasciatus and Ae. aegypti, respectively. The corresponding EI50 values were 0.006, 0.048 and 0.249 ppm. On treatment, NeemAzal T/S induced certain morphogenetic abnormalities, broadly characterized in five types, in larvae, pupae and adults of all the three vector species. The percentage of dead specimens of any stage showing morphogenetic abnormalities was the maximum in Cx. quinquefasciatus (14.4%; n=2113) followed by Ae. aegypti. Interpretation & conclusions: Our results indicated that because of its emergence inhibition activity, NeemAzal T/S 1.2 per cent EC could be a promising candidate for the use in integrated vector management programme and replace chemical insecticides.

Leaf extracts of Melia azedarach Linnaeus (Sapindales: Meliaceae) act as larvicide against Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae) / Extratos de folhas de Melia azedarach Linnaeus (Sapindales: Meliaceae) atuam como larvicida de Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae)

The objective of this study was to compare the larvicidal effect of hydroethanolic extracts of fresh and dry leaves of Melia azedarach Linnaeus (Sapindales: Meliaceae) on Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). All the extracts evaluated induced mortality among the third and fourth instar larvae of Aedes aegypti after 24 and 48 hours of exposure to the products. Although previous studies had demonstrated the action of seeds and fruits of Melia azedarach against the larvae of different Aedes aegypti populations, the present report is the first to show the larvicidal effect of the fresh and dry leaves of this plant.

O objetivo deste trabalho foi comparar o efeito larvicida de extratos hidro-etanólicos de folhas verdes e secas de Melia azedarach Linnaeus (Sapindales: Meliaceae) em Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae). Todos os extratos avaliados induziram mortalidade em larvas de 3º e 4º estágios de Aedes aegypti, após 24 e 48 horas de exposição aos produtos. Embora estudos prévios tenham demonstrado a ação de sementes e frutos de Melia azedarach em larvas de diferentes populações de Aedes aegypti, o presente estudo é o primeiro a reportar o efeito larvicida de folhas verdes e secas desta planta.

Removal of fluoride by thermally activated carbon prepared from neem (Azadirachta indica) and kikar (Acacia arabica) leaves.

The present investigation deals with fluoride removal from aqueous solution by thermally activated neem (Azadirachta indica) leaves carbon (ANC) and thermally activated kikar (Acacia arabica) leaves carbon (AKC) adsorbents. In this study neem leaves carbon and kikar leaves carbon prepared by heating the leaves at 400 degrees C in electric furnace was found to be useful for the removal of fluoride. The adsorbents of 0.3 mm and 1.0 mm sizes of neem and kikar leaves carbon was prepared by standard sieve. Batch experiments done to see the fluoride removal properties from synthetic solution of 5 ppm to study the influence of pH, adsorbent dose and contact time on adsorption efficiency The optimum pH was found to be 6 for both adsorbents. The optimum dose was found to be 0.5g/100 ml forANC (activated neem leaves carbon) and 0.7g/100 ml forAKC (activated kikar leaves carbon). The optimum time was found to be one hour for both the adsorbent. It was also found that adsorbent size of 0.3 mm was more efficient than the 1.0 mm size. The adsorption process obeyed Freundlich adsorption isotherm. The straight line of log (qe-q) vs time at ambient temperature indicated the validity of langergren equation consequently first order nature of the process involved in the present study. Results indicate that besides intraparticle diffusion there maybe other processes controlling the rate which may be operating simultaneously. All optimized conditions were applied for removal of fluoride from four natural water samples.

Larvicidal activity of neem and karanja oil cakes against mosquito vectors, Culex quinquefasciatus (say), Aedes aegypti (L.) and Anopheles stephensi (L.).

Larvicidal effect of neem (Azadirachta indica) and karanja (Pongamia glabra) oil cakes (individuals and combination) was studied against mosquito species. Both the oil cakes showed larvicidal activity against the mosquito species tested. The combination of neem and karanja oil cakes in equal proportion proved to have better effect than the individual treatments. The combination of the two oil cakes recorded an LC95 of 0.93, 0.54 and 0.77% against the mosquitoes, Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi respectively The increase in efficacy of the combination treatment over individuals in all the mosquito larvae tested was found to range about 4 to 10 fold in terms of LC50 and 2 to 6 fold in terms of LC95.

Azadirachta indica leaf extract modulates initiation phase of murine forestomach tumorigenesis.

The effects of aqueous Azadirachta indica leaf extract (AAILE) on benzo(a)pyrene [B(a)P]-induced forestomach tumorigenesis, B(a)P-DNA adduct formation and certain parameters of carcinogen biotransformation system in mice have been reported earlier from our laboratory. In this study, the effects of AAILE on the enzymes of B(a)P biotransformation, which play crucial role in initiation of chemical carcinogenesis - aryl hydrocarbon hydroxylase (AHH) and uridinediphosphoglucuronosyltransferase (UDP-glucuronosyltransferase) have been evaluated in murine forestomach and liver. In addition, lipid peroxidation (LPO) levels in forestomach as well as liver and the activities of tissue injury marker enzymes - lactate dehydrogenase, aspartate aminotransferase and alkaline phosphatase in the serum have also been evaluated. Oral administration of AAILE (100 mg/kg body wt for 2 weeks) reduces the AHH activity and enhances the UDP-glucuronosyltransferase activity in both the tissues, suggesting its potential in decreasing the activation and increasing the detoxification of carcinogens. The LPO levels decrease upon AAILE treatment in the hepatic tissue, suggesting its antioxidative and hence anti-carcinogenic effects. Non-significant alterations have been observed in tissue injury marker enzymes upon AAILE treatment, suggesting its safety at the given dose. In conclusion, AAILE appears to modulate initiation phase of carcinogenesis and may be suggested as safe and an effective agent for chemoprevention.

Piscicidal potential of mesocarp of neem plant (Azadirachta indica L.) fruit on hybrid, "Heteroclarias".

The piscicidal potential of water-extract mesocarp of Azadirachta indica (L) was studied in static bioassay experiment with continuous aeration to determine its acute toxicity The mortality rate and opercular ventilation under laboratory conditions over 96 hr exposure were monitored. The 96 hrLC50 was 81.28 mgl(-1) while the threshold value was 21.13 mgl(-1). The fish exhibited respiratory distress (such as gasping air), loss of appetite, loss of balance and erratic swimming prior to mortality.

Impediment of diethylnitrosamine induced hepatotoxicity in male Balb/c mice by pretreatment with aqueous Azadirachta indica leaf extract.

Considering the hepatoprotective properties of Azadirachta indica, the present study was designed to evaluate its preventive effects against diethylnitrosamine (NDEA) induced hepatotoxicity in male Balb/c mice. Exposure of NDEA caused a significant increase in micronucleated cell score, lipid peroxidation levels (LPO) and activity of lactate dehydrogenase (LDH). A significant decrease in reduced glutathione (GSH) contents and activity of glutathione-S-transferase (GST) was also observed upon NDEA treatment, whereas their activities of cytochrome P450 and cytochrome b5 showed non-significant alterations. Aqueous A. indica leaf extract (AAILE) pretreatment showed protective effects against NDEA induced toxicity by decreasing the frequency of micronucleated cell, levels of LPO and LDH activity. Also, a decreased activity of GST, cytochrome P450 and an increased activity of cytochrome b5, GSH contents was observed when AAILE pretreated mice were injected with NDEA. Only AAILE treatment caused a noticeable decrease in the frequency of micronuclei, activity of cytochrome P450 and cytochrome b5, but a significant increase in the activity of GST and GSH contents, whereas, non significant alterations were observed in the activity of LDH and levels of LPO. Significance of these observations with respect to hepatoprotective efficacy of A. indica has been discussed in the present manuscript.

Toxicity of neem pesticides on a fresh water loach, Lepidocephalichthys guntea (Hamilton Buchanan) of Darjeeling district in West Bengal.

Static renewal bioassay tests were conducted to evaluate the acute toxicity of two neem based biopesticides, applied widely on tea plantation namely, Nimbecidine and Neem Gold either separately as well as, in combination to the fingerlings (mean body length- 4.46 +/- 0.15 cm; mean body weight- 0.49 +/- 0.15g) of a fresh water loach, Lepidocephalichthys guntea (Hamilton Buchanan) acclimatized to laboratory conditions prior to experiment. The 96 hours LC50 values for Nimbecidine and Neem Gold and the combination of the two were 0.0135 mgl(-1), 0.0525mgl(-1) and 0.0396 mgl(-1), respectively. The regular water quality analysis showed, that with increasing doses of biopesticides, dissolved oxygen level was lower and other parameters like pH, free carbon dioxide, total alkalinity total hardness, chloride ions of water increased. The fish under toxicity stress suffered several abnormalities such as erratic and rapid movement, body imbalance and surface floating responding proportionately to the increase in concentrations of the toxicant biopesticides. The 96 hours LC50 values proved Nimbecidine more toxic than Neem Gold and the combination of the two biopesticides.

Effect of aqueous extract of neem (Azadirachta indica) leaves on offensive and diffensive gastric mucosal factors in rats.

Standardized aqueous extract of Neem (Azadirachta indica) leaves (AIE) has been reported to show both ulcer protective and ulcer healing effects in normal as well as in diabetic rats. To study the mechanism of its ulcer protective/healing actions, effects of AIE (500 mg/ kg) was studied on various parameters of offensive acid-pepsin secretion in 4 hr pylorus ligation, pentagastrin (PENTA, 5 microg/kg/hr)-stimulated acid secretion and gastric mucosal proton pump activity and defensive mucin secretion including life span of gastric mucosal cells in rats. AIE was found to inhibit acid-pepsin secretion in 4 hr pylorus ligated rats. Continuous infusion of PENTA significantly increased the acid secretion after 30 to 180 min or in the total 3 hr acid secretion in rat stomach perfusate while, AIE pretreatment significantly decreased them. AIE inhibited the rat gastric mucosal proton pump activity and the effect was comparable with that of omeprazole (OMZ). Further, AIE did not show any effect on mucin secretion though it enhanced life span of mucosal cells as evidenced by a decrease in cell shedding in the gastric juice. Thus, our present data suggest that the ulcer protective activity of AIE may be due to its anti-secretary and proton pump inhibitory activity rather than on defensive mucin secretion. Further, acute as well as sub acute toxicity studies have indicated no mortality with 2.5 g/kg dose of AIE in mice and no significant alterations in body or tissues weight, food and water intake, haematological profile and various liver and kidney function tests in rats when treated for 28 days with 1 g/kg dose of AIE.

Antioxidative and modifying effects of a tropical plant Azadirachta indica (Neem) on azoxymethane-induced preneoplastic lesions in the rat colon.

The purpose of the present study was to examine whether Neem leaf (Azadirachta indica) has short-term chemopreventive effects on endpoint preneoplastic lesions involved in rat colon carcinogenesis and might also exert antioxidative activity. Forty- two male F344 rats were randomly divided into 6 experimental groups. Groups 1 to 4 were given a subcutaneous injection of azoxymethane (AOM, 20 mg/kg body weight) once a week for 2 weeks. Starting one week before the first injection of AOM, rats in groups 2 to 4 received an aqueous extract of Neem leaf (20, 100, and 250 mg/kg, respectively) by gavage 3 times per week, for 5 weeks. Rats in group 5 also were given the Neem extract by gavage feeding 3 times per week for 5 weeks, while group 6 served as untreated controls. The experiment was terminated 5 weeks after the start. Dietary feeding of the Neem extract at all dose levels significantly inhibited the induction of aberrant crypt foci (ACF) (P<0.0002), when compared to the AOM-treated group (group 1). In groups 2 to 4, treatment of rats with the Neem extract also significantly decreased the proliferating cell nuclear antigen (PCNA) labeling indices (P<0.0006) of colon epithelium and ACF. Moreover, the Neem extract also showed antioxidative activity. The finding that dietary Neem has possible chemopreventive effects in the present short-term colon carcinogenesis bioassay suggests that longer-term exposure may cause suppression of tumor development.