The In Silico Toxicity of Serai Wangi (Cymbopogon nardus) and Mimba (Azadirachta indica

Antifungal activity of nano emulsions of neem and citronella oils against phytopathogenic fungi, Rhizoctonia solani and Sclerotium rolfsii

The efficacy of various botanicals was tested against the major pest of groundnuts, the peanut moth Corcyra cephalonica, in Lab conditions for one year. Essential oils isolated by Clevengers Apparatus, @1% (v/w) of Pongamia glabra (Karanja Oil), Azadirachta Indica (Neem Oil), Brassica campestris (Mustard Oil) , Crown oil (Resin of Shorea robusta) , Cymbopogon nardus (Citronella) oil , Dalbergia sisso (Sisso Oil), Oryza sativa (Rice bran oil), Helianthus annus(Sunflower Oil) , Ricinus communis (Castor Oil), Aegle marmelos (Bael Oil), Sesamum indicum (Til Oil), etc were tested for their bioefficacy against the major pest, of groundnuts, Corcyra cephalonica , in Laboratory conditions for one year. Out of all these plant products Cymbopogon nardus (Citronella) oil and Crown oil (Resin of Shorea robusta) gave absolute pod/Kernel protection for one year. The LD50 values were found out to be - 0.5% v/w. Spectroscopic GC MS analysis of Citronella oil (Cymbopogon nardus), lead to the identification of D-Limonene, Neral, Citral and 2,6-octadien-1-ol,3,7-dimethyl acetate (Z) as essential main constituents. Spectroscopic GC MS analysis of Crown oil (Resin of Shorea robusta) are identified as 2-Ethyl-oxetane (RT 2.223), as the major product. It may be due to the aromatic nature of these phyto-products. Hence these phyto-products may be used as fumigants or insect repellants against Corcyra cephalonica and can be included in the package of practices to save stored groundnut in storage.

Oil extracted from neem seed was investigated for use as alternative cutting fluid in metal machining operation using mild steel at three different values each of cutting speeds, depth of cut and oil ratios. Physicochemical properties that relate to cutting fluid’s performance like cooling effect (temperature rise) and surface roughness were measured and compared to those of conventional cutting oil bought from the market and also with data obtained in dry metal cutting experiment with no lubricant. Results indicated that neem had flash point of 157°C, pour point of +8°C, kinematic viscosity of 8.08cSt at 100°C. Specific gravity at 14/40°C was 0.9304, sulpur content was 0.0293%, pH was 5.6 and free fatty acid (oleic acid) was 5.94%. Cooling effect was found to be comparable at different oil ratios and speeds, but dry machined surfaces produced the least cooling effect with temperature rise of up to 57.33°C at 710rpm at 0.5mm depth of cut. However, neem was found to perform slightly better than the soluble oils in most of the test results. Surface roughness for neem, soluble oil and dry machining were in the range of 0.002 μm and 1.427 μm. The least surface quality was obtained with neem oil at a speed of 250 rpm; depth of cut of 1mm at 50% oil and 50% water mixture. However all surface roughness was within the recommended standard that is the acceptable value for turned and machined surfaces with maximum value set at 25μm.

As plastics degrade into micro- and nano-sized particles, they can leach additive chemicals into the environment, potentially exerting greater toxicity than the polymer matrix itself. The ECHA Plastic Additives Initiative has compiled a list of more than 400 plastic additives that are used in high volumes. This study aimed to screen the potential toxicity of these chemicals using Tox21 bioassays and deep learning models. To this end, we collected the Tox21 dataset, which provides extensive bioactivity profiles for over 7,000 chemicals across various endpoints, including human nuclear receptor signaling and stress response pathways. We then trained deep learning models using experimental data from Tox21 bioassays. Specifically, we employed the GROVER algorithm, which was designed to overcome typical limitations of traditional graph neural networks by leveraging transformers and self-supervised pretraining. We fine-tuned the model on twelve Tox21 bioassay datasets, using the F1 score as the primary evaluation metric. As a result, the GROVER model outperformed baseline algorithms, including graph convolutional networks, random forest, support vector machines, and logistic regression. Using the fine-tuned GROVER models, we identified 78 highly active chemicals among 171 additives. For these active plastic additive chemicals, we also investigated existing hazard information (minimal oral point-of-departure) from the CompTox Chemical Dashboard and their Globally Harmonized System of Classification and Labelling of Chemicals (GHS) information from PubChem DB. This approach revealed significant data gaps for plastic additive chemicals with potential toxicity and can support regulatory decision-making. Collectively, this study provides a practical use case for applying cutting-edge AI models as new approach methodologies (NAMs) to modernize hazard assessment, in alignment with the 3Rs (Replacement, Reduction, Refinement) principle for animal testing.

Corcyra cephalonica is storage insect pest that are polyphagous. (Cymbopogon nardus L.) is a plant from the Gramineae group that produces essential oils. Useful as an insect repellent. In addition to the use of citronella, the pest attack of Corcyra cephalonica can be overcome with neem leaf extract. Neem is a plant that contains ingredients that can overcome pests on plants. This research was conducted to find out the test of repellency of citronella essential oil and neem leaf extract on repellent of Corcyra cephalonica by knowing the right concentration in biological pest management applications. The study used the basic pattern of non-factorial RAL. Used a dual-choice method. Treatment, (A1) : 10% citronella oil (A2) : 15% citronella oil (B1) : 10% neem extract (B2) : 15% neem extract. the results of the research that have been obtained, it can be concluded that the response of citronella essential oil and neem leaf extract to the rejection of Corcyra cephalonica at the larval stage were significantly different. The repellent of citronella essential oil and neem leaf extract of the imago stage were very significantly different. The highest percentage of imago repellency was in the 15% neem leaf extract treatment.

The Aedes aegypti mosquito can develop an immune system against the insecticide used. Control efforts with the use of insecticides are no longer effective if the target insects have become resistant. So there needs to be an effort to overcome the insect resistance that is targeted. Citronella grass is an herbal plant that can be used as an ingredient in vegetable pesticides. The leaves and stems are distilled to produce essential oil known as citronella oil. This research is about studying the effects of citronella oil against the resistance of the vector carrier for dengue fever, namely Aedes aegypti. The detection of citronella essential oil (Cymbopogon nardus L.) by Thin Layer Chromatography showed a reduction in UV254 visualization (Rf 0,68). The resistance test showed that the mortality percentage of adult mosquitoes Aedes aegypti exposed to 0.03% alphacymethrin was 73,7% resistant criteria (<90%). The mortality percentage of adult mosquitoes Aedes aegypti exposed to Alphacypermethrin (0,03%) and citronella oil was 2,5% each; 5%; 7,5% and 10% with treatment time 15 respectively, namely 18,7%, 50,7%, 70,7% and 82,7%; the treatment time of 30 minutes consecutively is 62,7%, 89,3%, 96% and 97,3% and the treatment time is 60 minutes respectively, namely 93,3%, 98,7%, 98,7% and 100%. There was an increase in the percentage of mosquito deaths exposed to the combination of alphacypermethrin and citronella oil, compared to those without citronella oil, this indicates that mosquitoes are more susceptible and resistance has decreased due to exposure to citronella oil.Â

The repellent effects of ten oils, Domba ( Calophyllum inophyllum L), Batu ( Solanam indicum L), leaf oil and bark oil of Cinnamon ( Cinnamomum verum Presl . ), Mustard oil ( Brassica juncea Cross.), Neem oil ( Azadiracta indica A.Juss), Mee oil ( Maduka longifolia Koenig.), Castor oil ( Ricinus communis L.), Citronella oil ( Cymbopogon nardus L.) and Sesame oil ( Sesamum indicum L.) were tested for pulse beetle ( Callosobruchus maculatus L.) in the laboratory conditions. Data were recorded on distribution, oviposition and adult emergence. Ventilated containers each with five pairs of newly emerged adults with 20 green gram seeds were exposed to different oil vapours at the rate of 200μml. Each container was fixed to a device that provided a tunnel for pulse beetle to escape from or enter into any container. Citronella oil, Neem oil, Cinnamon leaf oil and Cinnamon bark oil vapours recorded significantly lowest number of pulse beetles after infestation and their oviposition and adult emergence indicating the highest repellent action and toxic effects. Mustard oil, Domba oil, Mee oil, Castor oil and Batu oil show indications of higher repellent effect at 4DAT on the distribution of the C. maculatus. Mustard oil and Domba oil showed a lower rate oviposition than that of Mee oil, Castor oil and Batu oil. All the treatments except Sesame oil had significantly reduced adult emergence at 18DAT. Sesame oil showed positive effect on distribution, oviposition and adult emergence and no repellent activity against the C. maculatus. Key words : C. maculatus ; Green gram; Oil vapours; Repellent effects DOI: 10.4038/tare.v12i1.1978 Tropical Agricultural Research & Extension 12(1):2009 13-16

Citronella is an aromatic grass of the family Poaceae which can be classified into two categories Ceylon Citronella (Cymbopogon nardus) and Java Citronella (Cymbopogon winterianus). The Citronella oil was extracted from five selected Ceylon Citronella (HP T1, HP T2 and HP T3) and Java Citronella (MP T1 and MP T2) accessions using steam distillation and hydrodistillation methods. Citronella oil quantity extracted by hydrodistillation with Xylene from Ceylon Citronella was higher (2.45-2.67 mL/100 g) than the Java Citronella (1.57-1.64 mL/100 g). The oil quantity of Ceylon Citronella (HP T1-5.52 %, HP T2- 1.40 %, HP T3- 1.05 %) and the quantity of Java Citronella (MP T1- 1.25%, MP T2- 1.79%) extracted by hydrodistillation showed a significant difference (P<0.0001) and there was no significant difference (P=0.7055) between the oil quantity of Ceylon (HP T1- 1.07%, HP T2- 1.18 %, HP T3- 1.19%) and Java (MP T1- 1.16%, MP T2- 1.23%) oils extracted by the steam distillation. Both Java and Ceylon Citronella oils showed organoleptic properties with pale yellow to pale brownish yellow colour and a strong citrusy aroma which meets the ISO 3848 and ISO 3849 standards. The oil of Ceylon Citronella accessions showed refractive index (1.465-1.487), relative density (0.893-0.910), and ethanol solubility (1:2 mL) within the ranges specified in SLS 170 standards. Java Citronella oil exhibited the refractive index (1.4660-1.4730), relative density (0.880-0.892), ethanol solubility (1:2 mL), and optical rotation (-5? to 0?) which meets the specifications of ISO 3848 standards. Geraniol, Citronellol, and Citronellal were identified as the major constituents using the gas chromatography-mass spectrometry (GC-MS) where Java Citronella oil showed high Geraniol content (48.60-49.17%) than Ceylon Citronella oil (16.93-26.49%). All types of tested Citronella oil showed inhibition against Candida albicans where HP T3 (1.9 cm) and MP T1(2.0 cm) oils showed the highest promising antifungal activity among Ceylon oils and Java oils respectively. Therefore, these two oils were selected for the antidandruff shampoo formulation. The two antidandruff shampoo samples were formulated with 2% v/v concentrations of HP T3 and MP T1 Citronella oil which were determined as MIC for the inhibition of C. albicans. Antidandruff shampoo tested against C. albicans showed greater antifungal activity (HP T3 - 2.50.05 cm; MP T1 - 2.50.05 cm) than the crude Citronella oil (HP T3- 1.90.11 cm; MP T1-2.00.1 cm), also attained the organoleptic and physical properties such as pH (4.0-8.0), foam height (>100 mL), dirt dispersion (no ink in foam), viscosity, low wetting time and solid content (HP T3-14.750.12%; MP T2-12.330.19%) in acceptable specification range. This study exhibits that Ceylon Citronella oil HP T1 has the highest oil quantity from all selected accessions. Hydrodistillation can be used to extract high oil quantity than the steam distillation method from both Java and Ceylon Citronella types. Compared to Ceylon Citronella oil, Java oil has significant potential industrial applications with high Geraniol content and with the highest antifungal activity against C. albicans. Also, the tested Citronella oil of all selected accessions of both Java and Ceylon types meet the organoleptic and physiochemical requirements specified by the ISO and SLS quality standards with excellent antifungal activity against C. albicans, which provides prospective to use Citronella oil as a natural, safe, and eco-friendly fungicide in future product formulations.

Lemongrass (Cymbopogon nardus L.) is an economically valuable plant that produces citronella oil and could grow on marginal lands. This study aimed to analyze citronella oil yields planted with agroforestry and monoculture patterns in a post-mining revegetation area. The treatment consisted of 3 factors, namely planting pattern, fertilizer dosage, and plant spacing. The measured variable was the citronella oil yield. The study was conducted by planting two lemongrass varieties i.e., Sitrona 2 Agribun Variety dan G2 Variety in the agroforestry and monoculture areas. The study was conducted for 12 months with three harvest times, i.e., in the 6th, 9th, and 12th months. The results showed that planting patterns significantly affected the citronella oil yield. Planting pattern of Monoculture-Sitrona 2 Agribun Variety (P4) produced the highest oil yield (1,95%). Plant spacing and dosage of bokashi fertilizer did not significantly affect the citronella oil yield. The Monoculture-Sitrona 2 Agribun Variety (P4) significantly increased the oil yield compared to the Agroforestry- Sitrona 2 Agribun Variety (P2), Monoculture-G2 Variety (P3), and Agroforestry-G2 Variety (P1) with a respective oil yield of 1,95% (P4), 1,50% (P2), 1,01% (P3), and 0,99% (P1). Sitrona 2 Agribun Variety tended to produce a higher oil yield than the G2 Variety. Keywords: agroforestry, citronella oil, lemongrass, oil yield, revegetation

Neem (Azadirachta indica) oil is a non-edible oil that contains azadirachtin, which can be used as a biopesticide. This study synthesizes bio-based polyurethane (PU) foam from neem and castor (Ricinus communis L.) oil at normal temperature and pressure. Neem oil can be reacted to narrow-distribution polyol by transesterification of oil and glycerol. Neem oil glyceride (NOG) can be used as polyol for bio-based PU foams and can be blended with castor oil homogeneously to reduce the cost of production. The composition of polyol was castor oil and 0 to 20% molar ratios of NOG. Hexamethylene diisocyanate trimer (Desmodur N) was used as isocyanate. The molar ratios of NCO/OH were set as 1.0, 1.5 and 2.0. The average hydroxyl contents of castor oil, neem oil and NOG were 2.7 mmol/g, 0.1 mmol/g and 5.1 mmol/g, respectively. The reaction time of bio-based PU foam could be adjusted between 5 to 10 min, which is acceptable for manufacturing. The densities of PU foams were between 49.7 and 116.2 kg/m3 and decreased with increasing NCO/OH and NOG ratios and decreasing neem oil. The ranges of specific compressive strength of foams were from 0.0056 to 0.0795 kPa·m3/kg. Increasing the NOG and neem oil ratio significantly enhanced the specific compressive strength in the low NCO/OH ratio. The solvent resistance and thermogravimetric (TG) results showed that the foams have high water and thermal stability. NOG can help to increase solvent resistance. Adding neem oil reduces the solvent resistance. The results indicated that increasing NCO/OH and NOG ratios increases the cross-linking density and hard segment content of PU foams. This investigation demonstrated that castor oil-based PU foams are improved by adding NOG to the polyol mixture. PU foam has excellent properties. Neem oil can be used in manufacturing processes to produce high-performance foams via a green synthesis process.

Nilaparvata lugens (Stal.) is one of the main insect pests of rice plant in Indonesia. The farmer usually using synthetic insecticide to control this pest insect. However, unwise of using insecticides cause many negative impact such as resistance, resurgence, environmental contamination, and healthy problem. These were encouraged to search and development of natural resources origin from plant for insect pest control. Neem (Azadirachta indica) and citronella (Cymbopogon nardus) have insecticidal activity and safety for the environment. This study aimed to compare the susceptibility of N. lugens from Cipunagara (field population) and Banyuwangi (standard population) to the insecticide formulation made from neem and citronella oil mixture (50:15). The experiments used leaf-stem dipping and root dipping methods. N. lugens instar 4th were exposed to the treated rice plant for two days and after that they were provided with rice plants without treatment until ten days. The results showed that the LC50 value in the root dipping method was lower than that in the leaf-stem dipping method. In this test, the toxicity of neem and citronella oil mixture formulation was higher in the root dipping method and was effective in controlling N. lugens in both populations with the LC95 values were 2.09%-2.30%. The Resistance Ratio (RR) of N. lugens from Cipunagara population and from Banyuwangi population were < 1 in both leaf-stem dipping and root dipping tests, respectively. Therefore, N. lugens from Cipunagara population is still susceptable to neem and citronella oil mixture formulation.

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.

Fungi of the genus Fusarium are well known plant pathogens, cause several vascular diseases and are producers of toxins. In vitro assays evaluated the effects of Neem (Azadirachta indica) oil on the diameter of colonies, dry weight, spore production, spore viability and production of Fusaric Acid toxin on Fusarium oxysporum f. sp. medicagenis and Fusarium subglutinans isolates. Effects of Neem oil were analyzed at concentrations 0.25%, 0.5% and 1% in Czapek Yeast Agar medium. The production of Fu- saric acid was determined by Thin Layer Chromatography and quantified by UV spectrophotometry. Neem oil showed inhibitory effects on the isolates tested, although they varied according to type of isolate and oil concentration. Neem oil was efficient in reducing the colonies’ diameter and dry weight in concentration-dependent manner. Neem oil was efficacious at higher concentration in the decrease of sporulation. Spore germination was affected by Neem oil when the spore was grown in Neem-contained medium as when the spore emerged from a culture in a Neem medium. Neem oil decreased and even inhibited the production of Fusaric acid by the assayed isolates. Since these isolates are plant pathogens and producers of Fusaric acid, Neem oil may be introduced as an integral item in the management of host plants.

O objetivo deste trabalho foi verificar o efeito do extrato hidroalcoólico e do óleo de nim sobre o crescimento micelial, esporulação, germinação e adesão de conídios do fungo F. oxysporum f. sp. vasinfectum e avaliar o efeito desses produtos na indução de resistência em quiabeiros tratados e, posteriormente, inoculados com o fungo, por meio da atividade de enzimas antioxidantes relacionadas com processos de defesa vegetal. Os resultados evidenciaram que tanto o extrato quanto o óleo de nim foram eficientes em inibir o crescimento micelial e esporulação do fungo. Além disso, houve inibição da germinação e fixação de conídios produzidos na presença dos produtos. O extrato e o óleo de nim reduziram a severidade da doença nos quiabeiros, medida pelo índice de infecção da doença. Além disso, incrementos significativos das enzimas guaiacol-peroxidase, polifenoloxidase, superóxido-dismutase e catalase foram observados nos quiabeiros tratados com os produtos, sendo estes aumentos, diretamente proporcionais aos aumentos das concentrações utilizadas. Assim, tanto o extrato quanto o óleo de nim têm efeitos diretos sobre o desenvolvimento do fungo F. oxysporum f. sp. vasinfectum e induzem resistência em quiabeiros a partir da formação de espécies reativas de oxigênio (EROs).

<div class="section abstract"><div class="htmlview paragraph">Non-edible vegetable oils have a huge potential for biodiesel production and also known as second generation feedstock’s. Biodiesel can be obtained from edible, non-edible, waste cooking oil and from animal fats also. This paper focuses on production of biodiesel obtained from mixture of sesame (<i>Sesamum indicum L.</i>) oil and neem (<i>Azadirachta indica</i>) oil which are easily accessible in India and other parts of world. Neem oil has higher FFA content than sesame oil. Biodiesel production from neem oil requires pretreatment neutralization procedure before alkali catalyzed Trans esterification process also it takes large reaction time to achieve biodiesel of feasible yield. Neem oil which has very high FFA and sesame oil which has low FFA content are mixed and this mixture is Trans esterified with no pre-treatment process using molar ratio of 6:1.Fuel properties of methyl ester were close to diesel fuel and satisfied ASTM 6751 and EN 14214 standards. Fatty acid composition of methyl ester of these oils are determined by Gas Chromatography (GC) technique. The oil characterization allowed the identification of nine fatty acids. The optimum biodiesel combination was further blended with diesel in various proportions to evaluate the emission and performance characteristics of single cylinder, direct injection, diesel engine. Parameters like, brake thermal efficiency, brake mean effective pressure, brake specific energy consumption and emissions of exhaust like carbon monoxide (CO), hydrocarbon (HC) and NOx produced by engine were recorded. The results obtained shows that various blends like B10 and B20 of mixed oil biodiesel (obtained from mixture of neem and sesame oil) with diesel can be used as an alternative fuel in C.I engine.</div></div>