Ambrosioides Essential Oil Research Articles

Chemical Profiling, Insecticidal, and Phytotoxic Effect of Essential Oils from Leaves and Inflorescence of Moroccan Chenopodium ambrosioides (L.).

Chenopodium ambrosioides (L.) is a medicinal and aromatic plant widely used in the Moroccan traditional medicine for its important pharmacological properties. In order to contribute to the valorization of this plant, the current study aimed at evaluating, for the first time, the variation in the yield, chemical composition, and insecticidal and phytotoxic activities of C. ambrosioides essential oil (CAEO) isolated from leaves and inflorescences. The results obtained showed that the CAEO yields vary significantly according to the distilled plant part, with 0.75 ± 0.15% for the leaves and 1.2 ± 0.34% for the inflorescences. CAEO profiling showed quantitative more than qualitative differences. Leaf CAEO was rich in δ-3-carene (61.51%), followed by p-cymene (14.67%) and 1,2:3,4-diepoxy-p-menthane (6.19%). However, inflorescence CAEO was dominated by the same compounds but with variable levels (δ-3-Carene: 44.29%; 1,2:3,4-diepoxy-p-menthane: 19.46%; and p-cymene: 17.85%). The CAEOs from the leaves and inflorescences showed a very interesting inhibiting effect on the germination and growth of the three species used, namely Medicago sativa, Linum rusitatissimum, and Raphanus sativus. However, there was no significant difference between these CAEOs. Similarly, for the insecticidal activity, CAEOs exhibited an important and similar toxicity against Tribolium confusum adults with LD50 of 4.30 and 4.46 μL/L of air and LD90 of 6.51 and 9.62 μL/L air for toxicity by fumigation, while values for contact toxicity on filter paper were 0.04 and 0.05 μL/cm2 for LD50 and 0.08 and 0.09 μL/cm2 for LD90.

Ethnopharmacological Study, Phytochemical Quality and Antibacterial Activity of the Essential Oils of Chenopodium ambrosioides, Eucalyptus camaldulensis and Origanum majorana from Taounate Region (Morocco)

This study aims to collect the traditional uses of three medicinal plants, Chenopodium ambrosioïdes, Eucalyptus camaldulensis and Origanum majorana, in Taounate region of Morocco and to evaluate the phytochemistry and antimicrobial activity of their essential oils. The ethnobotanical survey showed that Eucalyptus camaldulensis is used to treat respiratory ailments (27%), followed by osteo-articular troubles (24%), neurological diseases (22%), genitourinary and also digestive tract ailments (11% for each), while only 2% use it against dermatological problems. Origanum majorana was recommended for cardiovascular diseases (31%), neurological diseases (25%), digestive tract diseases (25%) and genitourinary infections (14%), as well as metabolic troubles (5%). While Chenopodium ambrosioides is mainly consumed to treat neurological diseases (37%), digestive diseases (35%) and skin conditions (20%). After hydrodistillation, the essential oils were analyzed by gas chromatography and mass-spectrometry (GC/MS). The main component of Chenopodium ambrosioides essential oil is α-terpinene (80.74%). For Eucalyptus camaldulensis essential oil, 1,8-cineole (34.16%) and (-)-spathulenol (21.21%) are the main compounds. As for Origanum majorana essential oil, terpinene-4-ol (39.80%), α-phellandrene (15.15%) and carene (12.06%) represent the major components. The antibacterial activity of these essential oils indicates a stronger inhibitory effect on Gram-positive strains than Gram-negative strains; with minimum inhibitory concentrations varying between 5-40 μL/mL.

Dysphania ambrosioides Essential Oil: An Eco-friendly Inhibitor for Mild Steel Corrosion in Hydrochloric and Sulfuric Acid Medium

Dysphania ambrosioides Essential Oil: An Eco-friendly Inhibitor for Mild Steel Corrosion in Hydrochloric and Sulfuric Acid Medium

Myorelaxant Effect of the Dysphania ambrosioides Essential Oil on Sus scrofa domesticus Coronary Artery and Its Toxicity in the Drosophila melanogaster Model.

Purpose: Alternative methods for the use of animals in research have gained increasing importance, due to assessments evaluating the real need for their use and the development of legislation that regulates the subject. The principle of the 3R’s (replacement, reduction and refinement) has been an important reference, such that in vitro, ex vivo and cord replacement methods have achieved a prominent place in research. Methods: Therefore, due to successful results from studies developed with these methods, the present study aimed to evaluate the myorelaxant effect of the Dysphania ambrosioides essential oil (EODa) using a Sus scrofa domesticus coronary artery model, and the toxicity of both the Dysphania ambrosioides essential oil and its major constituent, α-terpinene, against Drosophila melanogaster in toxicity and negative geotaxis assays. Results: The EODa relaxed the smooth muscle of swine coronary arteries precontracted with K+ and 5-HT in assays using Sus scrofa domesticus coronary arteries. The toxicity results presented LC50 values of 1.546 mg/mL and 2.282 mg/mL for the EODa and α-terpinene, respectively, thus showing the EODa and α-terpinene presented toxicity to these dipterans, with the EODa being more toxic. Conclusions: Moreover, the results reveal the possibility of using the EODa in vascular disease studies since it promoted the relaxation of the Sus scrofa domesticus coronary smooth muscle.

Characterization of Dysphania ambrosioides (L.) Mosyakin & Clemants essential oil from Vietnam

DDysphania ambrosioides (L.) Mosyakin & Clemants is a fragrant herb widely distributed from warm temperate regions to subtropical and tropical regions of the Northern Hemisphere. The essential oil from D. ambrosioides is the main ingredient used in traditional medicine due to its anti-malarial, anti-cancer, and anti-helminthic properties, among others. The chemical composition of D. ambrosioides essential oil from the aerial part was extracted by hydrodistillation and analysis by gas chromatography-mass spectrometry, resulting the yield of 0.8%. The main components were characterized as 2,3-dehydro-1,4-cineole (55%), α-terpinene (15.2%), iso-ascaridole (15.3%), and p-cymene (9.8%), respectively.

Role of Ascaridole and p-Cymene in the Sleep-Promoting Effects of Dysphania ambrosioides Essential Oil via the GABAergic System in a ddY Mouse Inhalation Model.

The essential oil obtained from Dysphania ambrosioides leaves (DAEO) has antifungal, antioxidant, and antimicrobial properties. This study investigated DAEO's chemical composition and its sleep-promoting effects via administration by inhalation in ddY mice. Ascaridole (35.5%) and p-cymene (47.2%) were the major components. To obtain insight into DAEO's effects on the central nervous system (CNS), ascaridole and p-cymene were evaluated for sedative activity by using the caffeine-treated excitatory mouse model. DAEO administration significantly decreased locomotor activity at all doses except 0.000 04 mg per 400 μL of triethyl citrate. Both ascaridole and p-cymene were highly effective in decreasing locomotor activity of excited mice by more than 50%. In addition, ascaridole and p-cymene prolonged the pentobarbital-induced sleeping duration by 42% and 77%, respectively. These effects were antagonized by coadministration of gamma-aminobutyric acid (GABAA)-benzodiazepine receptor antagonist, flumazenil (3 mg/kg), indicating that the GABAergic system mediates the sedative effect. Finally, inhaled ascaridole and p-cymene had no negative effect on motor coordination, as observed during the Rota-rod test. Therefore, via activation of the GABAergic system, ascaridole and p-cymene mediate the sleep-promoting effect of DAEO. The results further extend the knowledge on their use as potential promising natural products for the management of sleep disorders and CNS-related ailments.

Essential oil from <i>Chenopodium ambrosioides L.</i> induces mitochondrial-mediated pathway and endoplasmic reticulum stress-related apoptosis in human liver cancer SMMC-7721 cells

Purpose: To evaluate the cytotoxic effect of essential oil derived from Chenopodium ambrosioides L. in Sichuan Province on human liver cancer SMMC-7721 cells, as well as its possible molecular mechanisms.Methods: Cytotoxicity was characterized by MTT assay and transmission electron microscopy (TEM) of SMMC-7721 cells ultrastructure. The apoptotic effect of the essential oil was evaluated by changes in mitochondrial membrane potential and Western blot assay.Results: MTT assay data indicate that the essential oil was cytotoxic to SMMC-7721 cells, while TEN revealed that there were vacuoles and nucleus fragmentation in the SMMC-7721 cell cytosol, cell swelling, and a large amount of leakage. Mitochondrial membrane potential assay and Western Blot data indicate that the essential oil induced cell apoptosis.Conclusion: The essential oil of Chenopodium ambrosioides L. in Sichuan Province seems to induce apoptosis of human liver cancer SMMC-7721 cells via the mitochondrial-mediated pathway and endoplasmic reticulum stress. Thus, this plant requires further investigation as a potential source of ananti-liver cancer drug.
 Keywords: Chenopodium ambrosioides Essential oil; Anti-tumor activity, Liver cancer Apoptosis, SMMC-7721 cells

Myorelaxant action of the Dysphania ambrosioides (L.) Mosyakin & Clemants essential oil and its major constituent α-terpinene in isolated rat trachea

This study aimed to investigate the myorelaxant action of the Dysphania ambrosioides essential oil (EODa) and its major constituent α-terpinene on tracheal smooth muscle isolated from rats. In tracheal smooth muscle ex vivo, in organ baths, isometric contractions recordings were done in order to evaluated the effect of EODa (1–1000 μg/mL) and α-terpinene (1–3000 μg/mL) on the following parameters: basal tone, contractions evoked by potassium (KCl 60 mM), acetylcholine (ACh 10 μM) or serotonin (5-HT 10 μM). The EODa and its major constituent α-terpinene, did not statistically alter basal tone; however, they induced myorelaxant effects on top of contractions induced by KCl, ACh and 5-HT. EODa and α-terpinene also inhibited the contractions induced by barium in presence of High [K+] (80 mM). The data suggest that the relaxation induced by these agents is caused by the inhibition of L-type VGCC, inhibiting the inward Ca2+ current through these channels, but does not exclude the possibility of participation of other mechanisms. Results from this study also suggest the EODa, due to their efficacy on relaxation of the respiratory tract, posses a therapeutic potential as a antispasmodic agent for respiratory tract.

The Essential Oil of Tunisian Dysphania ambrosioides and its Antimicrobial and Antiviral Properties

The essential oil obtained from Dysphania ambrosioides, a fragrant plant growing wildly in Tunisia, was extracted by hydrodistillation and analyzed using GC-MS and GC-FID techniques. Forty-four components were identified in the essential oil (EO), representing 88.95 % of the total hydrodistilled oil. The most abundant components were cis-ascaridole (60.33 %), m-cymene (22.17 %) and α-terpinene (1.79 %). The oil obtained from Tunisian D. ambrosioides, showed a notable antiviral activity against CV-B4 virus with IC50 equals to 21.75 μg/mL. The EO showed no toxicity on the HEp-2 cell line as evidenced by its low Cytotoxic Concentration 50 (CC50) that is estimated by 1617.22 μg/mL with a good selectivity index (SI = 74.348). D. ambrosioides essential oil showed a notable antiviral activity against CV-B4 virus with IC50 equals to 21.75 μg/mL. The EO showed strong antibacterial activity against Pseudomonas aeruginosa and Bacillus subtilis bacterial strains as well as antifungal activity against the pathogenic strain Candida albicans. The encouraging results indicate that D. ambrosioides essential oil might be explored as a natural source of antiseptic products relatively safer comparable to versatile synthetic alternatives. Meanwhile these results should be further supported by clinical trials to confirm the claimed activity.

Antifungal and repellent activities of the essential oils from three aromatic herbs from western Himalaya

Abstract In this investigation we examined the essential oils of three aromatic plants, Zanthoxylum armatum, Juniperus communis, and Dysphania ambrosioides, which are used by the local population of the western Himalayan region for medicinal purposes. These plants were studied for their antifungal, larvicidal and biting deterrent activities. Additionally, chemical compositions of the oils were determined by GC-MS and their odor evaluated. The main compounds were 2-undecanone (47.7%) and 1,8-cineol (20.5%) from Z. armatum and α-pinene (43.2%) and limonene (34.7%) from J. communis. p-Cymene (36.3%) and ascardiole (31.2%) were found as the main components of D. ambrosioides essential oil. Antifungal activity was evaluated against three Colletotrichum species. Dyspania ambrosioides oil showed the best activity against these strawberry anthracnose causing fungi. It also demonstrated biting deterrent activity against Aedes aegypti similar to DEET as positive control, whereas Z. armatum and J. communis were less effective against Colletotrichum and mosquitoes.

Inhibition of the essential oil from Chenopodium ambrosioides L. and α-terpinene on the NorA efflux-pump of Staphylococcus aureus

This study was carried out to test the essential oil from C. ambrosioides leaves and its main constituent, α-Terpinene, in an antibacterial activity assay. As well, it was evaluated ability reduce resistance to norfloxacin and ethidium bromide was compared the Staphylococcus aureus 1199B whith 1199 wild type strain. The MIC of the C. ambrosioides essential oil and α-Terpinene were determined by microdilution method. The MIC of the essential oil and α-Terpinene presented a value ≥ 1024 μg/mL. However, when associated with antibacterials, the essential oil from C. ambrosioides leaves significantly reduced the MIC of antibiotics and ethidium bromide, characterizing an efflux pump inhibition. The C. ambrosioides essential oil, despite having no direct antibacterial activity against the S. aureus 1199B strain, showed a potentiating action when associated with antibacterial agents, this being attributed to an inhibition of efflux pumps.

Payer Perspective of the American Academy of Sleep Medicine Clinical Practice Guideline for the Pharmacologic Treatment of Chronic Insomnia

Payer Perspective of the American Academy of Sleep Medicine Clinical Practice Guideline for the Pharmacologic Treatment of Chronic Insomnia

English

Essential oils are natural complex substances biosynthesized by plants, and many of them have antimicrobial properties. Dysphania ambrosioides is a medicinal plant traditionally used as an anthelmintic medicine. In this study, the antifungal activity of D. ambrosioides essential oil was tested against Botrytis cinerea, which is responsible for large economic losses in the post-harvest of roses. Inflorescences of D. ambrosioides yielded 1.3 mg.g-1 of essential oil in fresh material, corresponding to a content of 0.13%. Gas chromatography coupled with mass spectrometry (GC-MS) revealed 11 compounds in the essential oil with ascaridol and O-cymene corresponding to 80% of the total. The essential oil reduced B. cinerea mycelial growth by approximately 60% and spores germination by 51% at the concentration of 1000 ppm. However, no apparent morphological changes were observed in scanning electron microscopy analyzes. The essential oil was not able to reduce mycelial growth on rose petals and caused a color change in the petals 24 h after the treatment. Although the essential oil has little potential to control B. cinerea on roses due to the color change it causes, its activity on mycelial growth and spores germination could be exploited in other pathosystems.   Key words: Rosa hybrida, grey mold, chenopodium ambrosioides.

Anticancer Effects of <i>Chenopodium ambrosiodes</i> L. Essential Oil on Human Breast Cancer MCF-7 Cells <i>In vitro</i>

Purpose : To investigate the most effective compound of C. ambrosioides essential oil for the induction of cell death in human breast cancer cells (MCF-7), and the mechanism of induction. Methods : MCF-7 cells were treated with essential oil and its two main components, 1-isopropyl-4- methylbenzene and α-terpinene, respectively, for 24 and 48 h in vitro. To determine their cytotoxicity on MCF-7 cells, in vitro cytotoxicity, 3-(4, 5-dimethylthaizol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and live/dead cell fluorescent staining were used. MCF-7 cellular superoxide dismutase (SOD), catalase (CAT) vitality and malondialdehyde (MDA) content were also evaluated. Results : MTT results showed that essential oil and its two main compositions significantly inhibited the growth of MCF-7 cells in 24 h (p < 0.05), which was consistent with the Live/dead cell fluorescent staining results. After 24 h incubation the average inhibition rate is 58.98 % for essential oil, 37.8 % for 1-isopropyl-4-methylbenzene and 32.09 % for α-terpinene. With increase in the concentration of essential oil and the two main components, the relative activity of SOD significantly decreased (p < 0.05), while the relative activity of CAT was gradually increased (p < 0.05), compared with control. MDA relative content significantly increased (p < 0.05) until the concentration was 1.25, 0.21 and 0.17 μg/ml for essential oil , 1-isopropyl-4-methylbenzene and α-terpinene , and thereafter significantly decreased (p < 0.05) , compared to control. Conclusion : The data suggest that the essential oil of C. ambrosioides and its two main components inhibit MCF-7 cell proliferation cell death by inducing oxidative damage. However, the two main components are less effective in their anticancer activity than the essential oil Keywords : Chenopodium ambrosioides L. Essential oil, 1-isopropyl-4-methylbenzene, α-Terpinene, Breast cancer MCF-7 cells, Antitumor activity

The toxicity and physiological effect of essential oil from Chenopodium ambrosioides against the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

In this study, the bioactivities of the essential oil of Chenopodium ambrosioides L. and its two main components, α-terpinene and p-cymene, were evaluated against the diamondback moth (DBM), Plutella xylostella (L.). The contact and fumigant toxicity of the essential oil significantly decreased as the DBM larval instar increased. The essential oil had 30-fold more potent toxicity against third-instar larvae than either α-terpinene or p-cymene. With respect to antifeedant activity, treatment with C. ambrosioides essential oil dose-dependently decreased leaf consumption by third-instar larvae, and the median antifeedant concentration (AFC50) was 66.81 mg/L at 24 h and 78.24 mg/L at 48 h after the treatment. Development of pupae was also inhibited, and the median concentrations of pupae weight inhibition (PWIC50) and percentage inhibition of pupation (PIC50) were 176.5 mg/g leaf and 111.6 mg/g leaf, respectively. In general, contact treatment with the essential oil significantly inhibited the activities of insecticide detoxifying enzyme, including carboxylesterase and glutathione-S-tranferases, whereas, fumigant exposure only altered carboxylesterase activity. At nearly all the tested concentrations, the essential oil induced the activities of superoxide dismutase, peroxidase, and catalase; however, peroxidase activity was inhibited by contact treatment. Thus, the essential oils from C. ambrosioides showed potential as new control products to combat field crop-infesting insect pests, and it may function as fumigant, insecticide synergist, antifeedant, or insect growth regulator.

CARACTERIZAÇÃO QUÍMICA E EFEITO DO ÓLEO ESSENCIAL DE ERVA-DE-SANTA-MARIA SOBRE O ÁCARO-RAJADO DE MORANGUEIRO

O ácaro-rajado, Tetranychus urticae Koch (1836) (Acari: Tetranychidae), é a principal praga na cultura do morangueiro. O objetivo deste trabalho foi a caracterização química do óleo essencial de Chenopodium ambrosioides L. e a avaliação de seus efeitos sobre o ácaro-rajado. Os compostos do óleo essencial foram identificados pelasanálises de CG-DIC e CG-EM. A mortalidade e a oviposição foram avaliadas após a pulverização do óleo (2,5; 5,0; 7,5 e 10,0% v v-1) sobre fêmeas do ácaro-rajado. O rendimento do óleo essencial foi de 0,3%, e os compostos identificados foram (Z)-ascaridol (87%), (E)-ascaridol (5,04%), p-cimeno (4,83%), a- terpineno (1,24%) e piperitona (0,7%). Os maiores valores para mortalidade e redução de oviposição observados foram 85% e 69%, respectivamente. O óleo essencial de C. ambrosioidesé uma opção promissora para o manejo do ácaro-rajado.

Chenopodium ambrosioides var. ambrosioides used in Moroccan traditional medicine can enhance the antimicrobial activity of conventional antibiotics

Chenopodium ambrosioides var. ambrosioides is used in the folk medicine as analgesic, antipyretic, antioxidant and to cure gastrointestinal disease, typhoid and dysentery. The chemical composition of the aerial part essential oil was assessed by GC/MS analysis and the main constituents found were: α-terpinene (23.77%), ascaridole (14.48%), p-cymene (12.22%), neral (8.08%), geraniol (5.60%), isoascaridole (2.96%) and 2-carene (2.77%).The antioxidant assays using (DPPH) free radical, β-carotene-linoleic acid and reducing power assays showed that C. ambrosioides var. ambrosioides essential oil presents a moderate antioxidant effect using DPPH assay and a high effect using both β-carotene/linoleic acid bleaching (IC50=3.03μg/ml) and reducing power assay (IC50=6.02μg/ml). The antimicrobial properties of the essential oil against a large panel of Gram-positive and Gram-negative bacteria and Candida strains showed an inhibitory effect against all tested strains. Gram-positive bacteria (Bacillus cereus, Micrococcus luteus) were generally found to be more sensitive than Gram-negative ones. Moreover, Candia albicans was the most sensitive for Candida strains. The in vitro association of essential oil and some commercial antibiotics showed a synergistic effect between studied essential oil and antibiotics. The lowest FICi values observed were obtained with the combination essential oil and cefixime (FICi=0,37–0,50) and essential oil-ciprofloxacin (FICi=0,28–0,75), respectively, for Gram-positive and Gram-negative bacteria. Whereas, the association essential oil-fluconazole showed total synergistic effect for the most used yeast.These results showed that the essential oil exhibited a high antimicrobial and antioxidant activities and a synergistic interaction between antibiotics. These findings are very promising and it can be useful for pharmaceutical treatment and natural therapies.

Nematicidal Constituents from the Essential Oil of Chenopodium Ambrosioides Aerial Parts

Essential oil of Chinese medicinal herb, Chenopodium ambrosioides aerial parts was found to possess nematicidal activity against the root‐knot nematodes, Meloidogyne incognita. The essential oil of C. ambrosioides was obtained by hydrodistillation and analyzed by gas chromatography‐mass spectrometry (GC‐MS). A total of 27 components of the essential oil were identified. The principal compounds in C. ambrosioides essential oil were (Z)‐ascaridole (27.27%), ρ‐cymene (19.05%), isoascaridole (14.75%), α‐pinene (6.33%) and α‐terpinene (5.12%). Bioactivity‐guided chromatographic separation of the essential oil on repeated silica gel columns led to isolate three volatile components ((Z)‐ascaridole, ρ‐cymene and isoascaridole) from the essential oil. The essential oil and (Z)‐ascaridole exhibited strong nematicidal activity against M. incognita with LC50 values of 49.55 μg/mL and 32.79 μg/mL, respectively. ρ‐Cymene and isoascaridole also possessed nematicidal activity against M. incognita with LC50 values of 435.89 μg/mL and 1323.51 μg/mL, respectively but weaker than the crude essential oil.

Allelopathic activity of Chenopodium ambrosioides L.

In the chinampas of San Andrés Mixquic, Mexico, the farmers allow Chenopodium ambrosioides L. to grow only where there are no crops. Previous studies suggest that this plant interferes with the growth of other plants. Given current concerns over pesticide use, it is important to understand the management and chemical properties of certain plant species with allelopathic potential since these species may help lessen herbicide dependency in agriculture. Extracts of C. ambrosioides L. were bioassayed in germination and hypocotyl growth inhibition tests of Amaranthus hypochondriacus L. A volatile active fraction was found. At a concentration of 0.552 μ/petri dish, C. ambrosioides essential oil inhibited germination of A. hypochondriacus by 50%, while the hypocotyl growth of previously-germinated seeds of the same species was inhibited by 50% with 0.509 μ/petri dish. α-Terpinene, γ-terpinene, p-cymene, limonene and ascaridole (1-methyl-4(l-methylethyl)-2-3-dioxibicyclo[2.2.2]oct-5-ene) were identified in the essential oil of C. ambrosioides. Ascaridole was the principal allelochemical; 0.098 μ/petri dish caused a 50% inhibition of A. hypochondriacus germination and 0.216 μ/petri dish inhibited hypocotyl growth of the same species by 50%. Another crop species, Phaseolus acutifolius A. Gray, grown hydroponically, was inhibited significantly with the lowest concentration of C. ambrosioides essential oil tested (0.15 ml/I). With higher concentrations, the primary root died and plant growth was visibly stunted. The management of C. ambrosioides as a means of pest control with allelopathy in the chinampa agroecosystem is discussed.

Chemical Composition and Cytotoxic Activity of &lt;i&gt;Chenopodium ambrosioides&lt;/i&gt; L. Essential Oil from Togo

The leaf essential oil of Chromolaena odorata L. (Chenopodiaceae) from Togo were steam-distilled, analyzed by GC and GC-MS for chemical composition and investigated in vitro for its potential cytotoxic activity on human epidermic cell line HaCat. The chemical composition showed that the main constituents of essential oil sample were respectively ascaridole (51.12 %), p-cymene (19.88 %), neral (8.70%) and geraniol (7.55%). The in vitro cytotoxicity bioassays on human cell line HaCaT revealed moderate toxicity level of C. ambrosioides essential oil IC50 with 700 μL.mL-1. Pure commercial neral standard showed high toxicity with IC50 value of 100 μL.mL-1). Conversely, pure ascaridole p-cymene and geraniol standards appeared almost non-toxic (IC50 &gt;1000 μL.mL-1), proving the major role played by neral in the overall toxicity showed by the C. ambrosiodes oil sample tested in this work. Keywords: Chenopodium ambrosioides; Essential oil; Ascaridole; p-cymene; HaCaT cell line; Cytotoxicity. DOI: 10.3329/bjsir.v44i4.4594 Bangladesh J. Sci. Ind. Res. 44(4), 435-440, 2009