Neem Essential Oils Research Articles

Chitosan nanoparticles and neem essential oil functionalized pullulan/gum arabic active edible biocomposites for fresh-cut guava preservation

The study demonstrates the preparation of active edible biocomposites using Pullulan (PUL) and Gum Arabic (GA), functionalized with Chitosan Nanoparticles (NCS) and Neem Essential Oil (NEO). These biocomposites addressed the issues of high hydrophilicity and poor barrier properties in packaging. The effects of varying NCS concentrations (1 %, 2 %, and 3 %) on various film properties were studied, while keeping PUL, GA, and NEO concentrations constant. The biocomposite containing NEO and 3 % NCS (PUL/GA/NCS3/NEO), significantly improved surface properties, transforming it from hydrophilic (water contact angle 55.49 ± 2.31°) to hydrophobic (115.01 ± 1.86°). Additionally, tensile strength increased by ∼12.77 MPa, elongation at break by ∼6.26 %, thermal stability (Toffset) by ∼22.49 °C, and water vapour barrier by ∼45.95 %, alongside enhanced UV-shielding, antimicrobial and antioxidant properties. The EDX analysis confirmed the biocomposite safety, with 55.7 % carbon (C), 3.6 % nitrogen (N), and 40.8 % oxygen (O). Moreover, in vitro biocompatibility tests on Human Embryonic Kidney (HEK-293) cells indicated non-cytotoxicity, with 86.82 ± 2.28 % viability after 72 h. Furthermore, the practical application of PUL/GA/NCS3/NEO solution was tested as an edible coating material for fresh-cut guava preservation. The coated guava better maintained storage quality parameters in terms of colour, weight loss, firmness, microbiological shelf-life and antioxidant activity, under both ambient and refrigerated conditions.

Evaluation of the Ixodicidal Effect of Neem Essential Oil (Azadirachta Indica) in Domestic Dogs Infested by Ticks (Rhipicephalus Sanguineus) in the Veterinary Clinic Castim from the City of Arenillas Province El Oro

The present investigation was carried out to evaluate the ixodicide effect of Neem Essential Oil (Azadirachta indica) in domestic dogs infested by ticks (Rhipicephalus sanguineus) that were admitted to the CASTIM Veterinary Clinic, through the use of a shampoo based on Neem essential oil. (Azadirachta indica) at two concentration doses of 20% and 30% and with its positive control Derrivante (Ethion¬ + Cypermethrin) at 10%. thus determining: the effectiveness of the concentration of Neem oil, the time range in which the ixodicide effect occurs after application and the comparison of the positive control Derrivante (Ethion + Cypermethrin) at 10% vs. Neem essential oil 20% and 30%. evidencing its effectiveness, promoting the solution to the problem presented by most dogs at the Coastal or Littoral region level. In this research projected a total of 36 dogs male and female patients were analyzed by non-probabilistic consecutive sampling significance level of 0.05% admitted to the Veterinary Clinic CASTIM in a period of four months, classifying them according to size, type of coat (short and long) and their habitat (inside and outside the home) as indicators in which the acaricide efficiency of essential oil of Neem both 20% and 30% with residual effect 15 days were assessed in addition to the commercial product have Derrivante (ethion + Cypermethrin) as a positive control. According to data obtained, Neem Oil 30% had a greater effect in relation to the concentration to 20%, demonstrating the degree of infestation of ticks declined significantly as at 5 observation.

Neem essential oil: Extraction, characterization, and encapsulation

In the present study, extraction of nutraceuticals from neem leaves (Azadirachta indica A. Juss) was optimized using different extraction methods and solvents. Nutraceuticals possessing antimicrobial activities has been studied. The maximum amount of yield of neem oil was obtained when methanol was used and the yield comes out to be 7.68±0.11% by weight. 100 µL of extracted neem oil was incorporated in three different types of hydrogels of different proportions such as Chitosan-Gelatin hydrogel (1:1. 1.67:1 and 1:5), Maltodextrin-Whey protein (1:2) and Gum Arabic hydrogel and the release behavior was determined. The neem nutraceutical release was maximum (89.99 %) in case of Chitosan-Gelatin hydrogel where chitosan and gelatin was in the ratio of 5:1 and the amount of nutraceutical present was 100 µL, whereas the amount of drug release was observed minimum (44.45 %) in Gum Arabic hydrogel.

Gelatin/sodium alginate-based biodegradable films functionalized by persimmon pectin/ovalbumin-stabilized neem essential oil Pickering emulsion: Application for cherry tomato preservation

This work aims to develop a biodegradable film with enhanced mechanical, water-barrier, and antimicrobial characteristics for the preservation of cherry tomatoes. Here, a persimmon pectin/ovalbumin (PN/OVA) stabilized-neem essential oil Pickering emulsion (NOPE) was added into the gelatin/sodium alginate-based blend matrix (GS). Even the biodegradability and transmittance of NOPE-rich film were decreased as compared to the control film, its flexibility, oxygen-barrier, and water-barrier performances significantly (P < 0.05) increased by 45.23 %, 32.32 %, and 37.02 %, respectively. The NOPE-loaded films destroyed the hyphal structure and reduced spore germination of Botrytis cinerea through slow-releasing neem essential oil (NO), in turn inhibiting the growth of B. cinerea. Finally, the prepared films were applied for cherry tomato preservation. Compared with the control, 2.0 wt%-loaded GS films greatly reduced the weight loss and disease incidence of cherry tomatoes by 57.33 and 72.4 %, respectively, owing to their excellent water resistance and slow-released properties. Thus, the addition of 2.0 wt% NOPE into GS film is of particular interest in the design of active biodegradable packaging films for fruit preservation.

Neem Essential Oil as an Antifungal Agent against Phyllosticta citricarpa.

The fungus Phyllosticta citricarpa is a quarantine phytopathogen responsible for causing citrus black spot (CBS) disease. To export fruits to CBS-free countries, they must undergo a sanitation process to ensure disease control. In this study, neem essential oil (NEO) was tested against P. citricarpa for the first time as an alternative sanitizer. In vitro experiments were conducted to determine the inhibition concentration of NEO for P. citricarpa, and the mode of action of the essential oil was evaluated. In vivo assays were performed to simulate the sanitization process used in packinghouses. NEO was characterized by GC-MS/MS. The results revealed that NEO at 100 μL·mL-1 exhibited a similar inhibitory effect as copper oxychloride, suppressing 89.68 ± 1.14% of fungal mycelium growth. Fluorescence microscopy experiments demonstrated that NEO functions by disrupting the cytoplasmic membrane of fungal hyphae, leading to their death within 30 minutes of contact with NEO. GC-MS/MS characterization revealed a high presence of phenolic compounds, which serve as the primary antifungal agents responsible for the action against fungal hyphae. In vivo assays showed that NEO at 100 μL·mL-1 also reduced microorganisms (CFU mL-1) by 93.00 ± 3.88% compared to the negative control. Overall, the results demonstrate that NEO can effectively serve as an alternative sanitizer against P. citricarpa in citrus packinghouses. Our findings allow future studies to explore the use of NEO for sanitizing other fruits and combating different phytopathogens to broaden its potential application in fruit sanitation for export.

Chemical Composition of the Essential Oil of Neem (Azadirachta indica A. Juss. ) Seeds Harvested in Senegal

Objective: To make better understanding of the neem seed composition (Azadirachta indica A. Juss.) particularly in Senegal by the extraction, the proportioning and the determination of the composition of its essential oil. Methods: The extraction of essential oil from neem seeds is carried out by hydro-distillation. The Gas Chromatography (GC) and Mass Spectrometry (MS) were used for analysis and identification of components. Findings: The yield of essential oil from dry neem seeds (95.7% dry matter) is 0.076%. The major compounds identified are 5,6-dihydro-2,4,6-triethyl- (4H) 1-3,5-dithiazine (39.1%), cis 1,2,4-Trithiolane, 3, 5-diethyl (7.9%), 1-H-indole 2,3-dione (7.9%), trans 1,2,4-Trithiolane, 3,5-diethyl (6.2%), and ethyl thioisobutyrate (4%). The classification of compounds reveals that the essential oil of neem seeds is composed of sulfur and nitrogen compounds (40.1%), sulfur compounds (25.3%), and nitrogen compounds (15.1%), sesquiterpenes (7.4%), Fatty Acid Esters (FAE) (1.5%) and hydrocarbons (0.4%). This composition reveals that neem essential oil is mainly composed of non-terpene compounds. Novelty: The method of analysis by GC-MS although being the most widely implemented in the quantification and identification of volatile compounds is not applied in the case of neem seeds of African origin. Keywords: Chemical Composition; Essential Oil; Neem; Azadirachta indica; Seeds

Biodegradable and Active Mulch Films: Hydrolyzed Lemon Peel Waste and Low Methoxyl Pectin Blends with Incorporated Biochar and Neem Essential Oil

Biodegradable and Active Mulch Films: Hydrolyzed Lemon Peel Waste and Low Methoxyl Pectin Blends with Incorporated Biochar and Neem Essential Oil

Agar/TiO2/radish anthocyanin/neem essential oil bionanocomposite bilayer films with improved bioactive capability and electrochemical writing property for banana preservation

Active agar (AG) bilayer films with bioactive capability and electrochemical writing property were developed for improving the postharvest quality of the banana. The antioxidant and antimicrobial capacity of the films were enhanced with the incorporation of red radish extract (RRE) and neem essential oil (NEO) into AG lower layer. The barrier and mechanical properties, retention of total anthocyanin and NEO content in the bilayer films were effectively improved with addition of TiO2 into the AG upper layer. Multicolor patterns were successfully written on the bilayer film containing RRE. The AG-TiO2+AG-RRE-NEO bilayer film exhibited the optimal preservations on banana fruits during the storage period, based on the characterization by fruits appearance, senescent spotting symptom, microbial analysis, weight loss and firmness. Thus, the AG-TiO2+AG-RRE-NEO bilayer film was expected to be a multifunction packaging material for banana preservation.

Prospects of Neem Essential Oil as Bio-Pesticide and Determination of Its Residues in Eggplant Plants During Crop Production Cycle

Essential oils and their derivatives are considered alternative means for controlling many harmful insects. As well, their rapid degradation in the environment and increased specificity do not harm beneficial insects. A method for the determination of Neem oil residues in eggplant (Solanum melongenaL.) by GC/Ms Mass is described. In this study, the effect of Neem essential oil (Azadirachta indica Juss) as biopesticide on the economical production of eggplant (Solanum melongena L.) was investigated. Prior to use, the volatile and organic constituents of commercial applied Neem essential oil were identified using FTIR analysis. After application, Azadirachtin is an active ingredient in neem oil which appears to cause 90% of the effect on most sucking pests. Among them, the major constituents are triterpenes known as limonoids, Nitrogen, Oxygen, Floride and Carbon atoms. Neem oil residues were detected in all samples from eggplant which were collected from the field after 12, 24 days of spraying. It appears that no effective material residue present.

Evaluation of essential oils against rice sheath blight disease in kuttanad wetland ecosystem

Field experiments were conducted at Rice Research Station, Kerala Agricultural University, Moncompu during Rabi 2018-19, Kharif2019 and Kharif 2020 under AICRIP programme for rice sheath blight control through organic essential oils. The tested essential oils were citronella oil, eucalyptus oil, cedar wood oil, nirgundi oil, lemon grass oil, clove oil, neem essential oil, emulsifier with standard check fungicide carbendazim 50 WP. The pooled analysis of three seasons showed that neem essential oil @ 2 ml/l was superior in reducing the sheath blight disease incidence (19.28 %) on par with standard check fungicide carbendazim 50 WP (21.64 %) and lemon grass oil @ 2 ml/l (23.11 %). The data on severity proved that the neem essential oil treatment resulted in less severity of sheath blight (16.32%) compared to lemon grass oil (17.85 %) and standard check fungicide carbendazim (18.91%). The neem essential oil treatment also yielded the highest (6532 kg/ha) followed by standard check fungicide carbendazim (5878 Kg/ha) and lemon grass oil (5762 kg/ha).

Botanical formulations for the ecological management of Myzus persicae (Sulzer) and Aphis gossypii (Clover) (Hemiptera: Aphididae) and their side effects on parasitoids

The peach aphid Myzus persicae (Sulzer) and cotton aphid Aphis gossypii (Clover) (Hemiptera: Aphididae) are considered to be key pests affecting greenhouse pepper crops in Argentina as a result of their frequent occurrence and the seriousness of the damage caused by their feeding behavior and the transmission of virus. The goal of this research was to determine the efficiency of botanical products to control aphids and their side effects on parasitoids in this crop. Thus, three biorational pest control formulations derived from essential oils (EO) and plant extracts (Es) were tested, namely (i) neem EO, cinnamon EO, clove EO, oregano EO and American marigold EO (formulation 1); (ii) garlic EO and cinnamon EO (formulation 2); (iii) garlic E and rue E (formulation 3); and a soy lecithin adjuvant (lecithin), and finally, a control (water spray method). For this research, a completely randomized design was replicated 3 times. These treatments were applied directly to the foliage by means of a backpack sprayer on a weekly basis until the end of this trial. Subsequently, the total number of healthy aphids and parasitized aphids (mummies) on every leaf was recorded in the field and the laboratory through repeated measures Analysis of Variance (ANOVA) and LSD Fisher method. The results showed that formulation 1 and formulation 3 recorded a lower number of aphids and mummies compared to the other treatments. This evidence would demonstrate that these formulations repel aphids and parasitoids without the lethal effects caused by the use of broad spectrum insecticides.

The Impact of Plant Essential Oils and Fine Mesh Row Covers on Flea Beetle (Chrysomelidae) Management in Brassicaceous Greens Production.

Simple SummaryThe popularity of brassicaceous leafy greens has grown in recent years due to health benefits and the local food movement. However, for many producers and especially organic producers, flea beetles represent a major challenge to production because they chew small holes in the leaves reducing quality and appearance. The goal of our project was to assess the efficacy of row covers and essential oils in controlling flea beetles as an alternative to organic and conventional insecticides. We grew Arugula and Mizuna mustard greens in replicated experimental plots in the spring and fall of 2019. We found that in most cases, plants within the Agribon and ProtekNet row cover treatments had the least amount of flea beetle damage and the highest yields, while plants within the essential oil treatments and organic insecticides did not differ from unsprayed, uncovered control plots. Conventional insecticides had an intermediate level of control against flea beetles, but did not perform as consistently as row cover treatments. We believe that row covers could provide a strong management method for all growers of brassicaceous leafy greens, especially where quality standards are high.Brassicaceous leafy greens are an important crop for small growers but are difficult to produce due to damage by flea beetles. Flea beetles are problematic for growers as they chew many small holes through leaves rendering produce unmarketable. We tested the efficacy of several essential oils, the woven-mesh row cover ProtekNet, and the spunbonded row cover Agribon, compared to organic and conventional insecticides and no spray controls in the spring and fall of 2019. We found that the two row cover treatments (Agribon and ProtekNet) provided the best control of flea beetles and associated damage. Thyme oil was highly phytotoxic and killed the crop entirely and rosemary and neem essential oils caused mild phytotoxic burns. Organic insecticides rarely performed better than the no spray control. While conventional insecticides controlled most flea beetles, the crop was often still too highly damaged to sell. The results of our study suggest row covers offer producers an effective method of flea beetle control that reduces their dependence on insecticides for conventional and organic production.

Comparison Between the Effect of Neem Oil and Neem Aqueous Extract on Tetranychus urticae Koch (Acari: Tetranychidae)

The two-spotted spider mite, Tetranychus urticae Koch is one of the most important pests responsible for yielding losses for many crops. For several years, chemical control of mites has been extensively practiced; a major problem in the control of T. urticae is the response to develop resistance to many acaricides, and so, scientists make efforts to replace the chemical acaricides with natural acaricides, as a mean to reduce negative impacts to human health and the environment. In the search for control alternatives, this study aimed to evaluate the effect of neem essential oil and the aqueous neem extract against adult females of Tetranychus urticae under laboratory conditions. Also, LC50 of each treatment was established and the obtained results revealed that the active essential oil of neem was more effective than the aqueous neem extract. LC50: 33.99 ppm and 260.30 ppm for neem oil and aqueous extract respectively. However, LC90 value was 238.83 ppm and 1813.70ppm for neem oil and aqueous extract, respectively.

Effectiveness of citronella, clove, and neem essential oil mix formulas against budok disease of patchouli plant

Synchytrium pogostemonis is a fungal pathogen causes budok disease of patchouli plant. A research to control the disease was conducted at Indonesian Spice and Medicinal Crops Research Institute. The research was purposed to evaluate effectiveness of mix combination and single formulas of citronella, clove, and neem essential oils against the disease. Two synthetic fungicides (benomyl and bourdeaux mixture) were also tested, as well as, water as a control treatment. One month-old patchouli plants were sprayed with single and mix combination formulas of those three essential oils (5 ml/l), benomyl (3 g/l), bourdeaux mixture (1 g/l) and water as much as (100-200 ml/plant) every two weeks for 5 times respectively. The result indicated that the mix essential oil formula of (neem+citronella) was the most effective in reducing budok disease incidence. Its effectiveness was higher (56.51%) then benomyl (47.82%) and bourdeaux mixture (52.18%). The mix formula of (citronella+neem) could be recommended for controlling budok disease of patchouli. The use of essential oil mix formulas, hopefully could control budok disease, inhibit the resistance of target pathogen, reduce phytotoxicity and concentration of the more toxic essential oil once, as well as, reduce the uses of synthetic pesticides.

In Vitro Activity of Neem (Azadirachta indica) Oil on Growth and Ochratoxin A Production by Aspergillus carbonarius Isolates.

Aspergillus carbonarius is a saprobic filamentous fungus, food spoiling fungus and a producer of ochratoxin A (OTA) mycotoxin. In this study, the in vitro antifungal activity of neem oil (0.12% p/p of azadirachtin) was evaluated against the growth of six strains of A. carbonarius and the production of OTA. Four different concentrations of neem oil were tested in addition to three incubation times. Only the concentration of 0.3% of neem oil inhibited more than 95% of the strain’s growth (97.6% ± 0.5%), while the use of 0.5% and 1.0% of neem oil showed lower antifungal activity, 40.2% ± 3.1 and 64.7% ± 1.1, respectively. There was a complete inhibition of OTA production with 0.1% and 0.3% neem oil in the four strains isolated in the laboratory from grapes. The present study shows that neem essential oil can be further evaluated as an auxiliary method for the reduction of mycelial growth and OTA production.

Toxic effects of some insecticides, herbicides, and plant essential oils against Tribolium confusum Jacquelin du val (Insecta: Coleoptera: Tenebrionidae).

Cereals are staple food for many countries and are grown on millions of hectares of land, but much of the harvest is wasted due to losses by pests. To minimize these losses, many pesticides are used which are damaging to the environment and human health. There are debates to get rid of these chemicals but they are still in use at large scale. An alternative control strategy for insect pests in storage houses is the use of botanicals. In this study, four plant essential oils, two plant extracts, two herbicides, and two insecticides were used against Tribolium confusum and the comparison of toxicity was made by calculating LC50 and LT50 values. LC50 values were higher for abamectin (2.09–10.23 mg/L) and cypermethrin (3.41–11.78 mg/L) insecticides followed by neem essential oil (7.39–19.24 mg/L) and citrus extract (10.14–24.50 mg/L). However, LC50 values were maximum in case of jaman plant extract (22.38–176.42 mg/L) followed by two herbicides, Logran (19.66–39.72 mg/L) and Topik (29.09–47.67 mg/L) However, LC50 values were higher for topic herbicide (24.098 ppm) and jaman essential oil (16.383 ppm) after four days of treatment. Abamectin and cypermethrin insecticides, neem essential oil and citrus plant extract also killed adults of T. confusum quicker as compared other essential oils, extracts and herbicides. Results revealed that botanical formulations being environmentally safe could be used instead of highly hazardous pesticides for stored products’ pests. This study also elaborates the non-host toxicity of herbicides commonly applied in our agroecosystem.

Chemical composition of neem and lavender essential oils and their antifungal activity against pathogenic fungi causing ginseng root rot

The aim of this study was to assess in vitro, the antifungal activity and characterize the chemical constituents of the essential oils of Azadirachta indica (neem) and Lavandula angustifolia (lavender). The essential oils of A. indica and L. angustifolia plants were tested against several isolates of pathogenic fungal genera causing root rot disease of ginseng. Agar plate assay indicated that lavender oil at 10% exhibited the highest inhibition index of (86.0±0.7%) against Sclerotinia nivalis mycelial growth. Neem and lavender oils at 5% v/v showed inhibition index against Alternaria panax (72.9±2.1 and 45.0±1%, respectively). Lavender oil at 5% (v/v) inhibited growth of S. nivalis (83.1±0.2%) and Cylindrocarpon destructans (49.2±1%). The gas chromatography-mass spectrometry (GC-MS) analysis showed that the major constituents of neem oil were fatty acids (94.8%). However, sesquiterpenes were the dominant constituents of the lavender oil (57.6%). The antifungal indices demonstrated in this study are a clear evidence of the potentiality of neem and lavender essential oils to control plant diseases caused by phytopathogenic fungi. Key words: Ginseng root rot, fungi, essential oils.

Standardization of microencapsulation process of volatile oil of Azadirachta indica

Neem oil microcapsule gel was successfully prepared with wall material including gelatin and gum Arabic using coacervation technique by the researcher as an outcome of standardization of microencapsulation process of volatile oil of Azadirachta indica . An essential oil is the volatile lipophilic component extracted from plants. The use of medicinal plants is a universal phenomenon. The plant Neem belongs to the big mahogany family of Meliaceae and the genus Azadirachta of A. indica . The diverse biological activities of Neem essential oils can be applied on a large scale as antioxidant, antimicrobial agents comprising many important benefits including their volatility, lower level of risk to the environment than with synthetic ones. Findings of the study revealed that best results of microcapsules formation using Neem oil were obtained when the ratio of oil:gum:gelatin was kept 2:4:4, at optimized 50°C temperature having initial pH 4.5 and final pH 9.5.

Assessing the potential of non-harmful, natural feeding deterrents tested on captive primates

ABSTRACTCrop damage by non-human primates can cause friction between local people, government wildlife agencies and conservationists. Consequently, developing effective, non-lethal methods to protect crops against primate foraging could benefit farmers, reduce conflicts between interest groups, and even promote primate conservation The purpose of this research was to (1) develop a simple, economical protocol for testing the deterrent properties of non-lethal plant substances on captive primates prior to testing in the field; (2) examine the preliminary effectiveness of neem (Azadirachta indica) and ocimum (Ocimum kilimandscharicum) essential oils, and spent coffee grounds (SCGs) as feeding deterrents in captive macaques. The test methods developed involved exposing primates to possible feeding deterrents whilst feeding and comparing to a control. This was used to identify likely repellent substances, which could then be tested in the field to determine their effectiveness against crop damage. SCGs were most effective at deterring the macaques; ocimum and neem essential oils were less effective, though animals appeared less willing to access food when protected by these oils than they were under control conditions.

Synthesis and characterization of zinc oxide–neem oil–chitosan bionanocomposite for food packaging application

Nano zinc oxide at different concentrations (0.1, 0.3 and 0.5%) and neem essential oil were incorporated into the chitosan polymer by solution cast method to enhance the properties of the bionanocomposite film. The functional groups, crystalline particle size, thermal stability and morphology were determined using FTIR, XRD, TGA and SEM, respectively. The results showed that 0.5% nano zinc oxide incorporated composite film have improved tensile strength, elongation, film thickness, film transparency and decreased water solubility, swelling and barrier properties due to the presence of neem oil and nano zinc oxide in the polymer matrix. Further antibacterial activity by well diffusion assay method was followed against Escherichia coli which were found to have good inhibition effect. In addition to this food quality application were carried against carrot and compared with the commercial film.