Comparative analysis of whole plant, flower and root extracts of Chamomilla recutita L. and characteristic pure compounds reveals differential anti-inflammatory effects on human T cells.

Introduction: Chronic inflammation is a hallmark of chronic wounds and inflammatory skin diseases. Due to a hyperactive and prolonged inflammation triggered by proinflammatory immune cells, transitioning to the repair and healing phase is halted. T cells may exacerbate the proinflammatory milieu by secreting proinflammatory cytokines. Chamomilla recutita L. (chamomile) has been suggested for use in several inflammatory diseases, implying a capability to modulate T cells. Here, we have characterized and compared the effects of differently prepared chamomile extracts and characteristic pure compounds on the T cell redox milieu as well as on the migration, activation, proliferation, and cytokine production of primary human T cells. Methods: Phytochemical analysis of the extracts was carried out by LC-MS/MS. Primary human T cells from peripheral blood (PBTs) were pretreated with aqueous or hydroethanolic chamomile extracts or pure compounds. Subsequently, the effects on intracellular ROS levels, SDF-1α induced T cell migration, T cell activation, proliferation, and cytokine production after TCR/CD3 and CD28 costimulation were determined. Gene expression profiling was performed using nCounter analysis, followed by ingenuity pathway analysis, and validation at protein levels. Results: The tested chamomile extracts and pure compounds differentially affected intracellular ROS levels, migration, and activation of T cells. Three out of five differently prepared extracts and two out of three pure compounds diminished T cell proliferation. In line with these findings, LC-MS/MS analysis revealed high heterogeneity of phytochemicals among the different extracts. nCounter based gene expression profiling identified several genes related to T cell functions associated with activation and differentiation to be downregulated. Most prominently, apigenin significantly reduced granzyme B induction and cytotoxic T cell activity. Conclusion: Our results demonstrate an anti-inflammatory effect of chamomile- derived products on primary human T cells. These findings provide molecular explanations for the observed anti-inflammatory action of chamomile and imply a broader use of chamomile extracts in T cell driven chronic inflammatory diseases such as chronic wounds and inflammatory skin diseases. Importantly, the mode of extract preparation needs to be considered as the resulting different phytochemicals can result in differential effects on T cells.

Azulene and Its Derivatives as Potential Compounds in the Therapy of Dermatological and Anticancer Diseases: New Perspectives against the Backdrop of Current Research.

The scientific article focuses on the role of azulene and its derivatives in the therapy of dermatological diseases, presenting the latest laboratory and clinical research as well as prospects for further studies. In a synthetic literature review, various databases such as PubMed, Scopus, Web of Science, and the Database of Polish Scientific Journals were queried to select relevant articles concerning azulene. The conclusions drawn from the thematic analysis of the studies emphasize the multifaceted pharmacological actions of azulene and its derivatives including their anti-inflammatory properties, potential anticancer effects, photoprotective abilities, alleviation of itching, management of atopic dermatitis, and treatment of erectile dysfunction. However, there are certain limitations associated with the application of unmodified azulene on the skin, particularly related to photodecomposition and the generation of reactive oxygen species under UV radiation. These effects, in turn, necessitate further research on the safety of azulene and azulene-derived substances, especially regarding their long-term use and potential application in phototherapy. The authors of this work emphasize the necessity of conducting further preclinical and clinical studies to fully understand the mechanisms of action. Incorporating azulene and its derivatives into the therapy of dermatological disorders may represent an innovative approach, thereby opening new treatment avenues for patients.

Screening of the essential oil of Thapsia garganica subsp. messanensis (Guss.) Brullo & al., an endemic plant of Sicily (Italy).

The genus Thapsia L., belonging to the Scandiceae tribe of the Apiaceae family, is mainly distributed in the Mediterranean area, North Africa, and the Iberian Peninsula. The use of plants of this genus in popular medicine dates back to the age of ancient Greeks. In the present study the chemical composition of the essential oil from aerial parts of Thapsia garganica subsp. messanensis (Guss.) Brullo & al., an endemic plant of Sicily, never previously investigated, was evaluated by GC-MS. The main components of its essential oil (Tgm) were 1,4-dimethylazulene (17.0%), chamazulene (10.1%), 3-methyl nonane (7.0%), and butyl heptanoate (4.6%). The comparison with all the other studied essential oils of the genus Thapsia is discussed.

Thin layer chromatography-direct bioautography for investigation of antibacterial activities of Artemisia sieversiana Ehrhart ex Willd. essential oil.

The aim of the study was to characterise the chemical composition of the essential oil extracted from a Chinese traditional aromatic herb, Artemisia sieversiana Ehrhart ex Willd and investigate its antimicrobial activities against Staphylococcus aureus, the test bacterium, using thin-layer chromatography-direct bioautography (TLC-DB). Gas chromatography-mass spectrometry analysis showed that the essential oil was dominated by chamazulene (44.44%). Undeveloped TLC-DB enabled the measurement of zone of inhibition as valid as and more sensitive than the traditional agar diffusion method. The overall antimicrobial effect was weak at the tested concentration range and the antimicrobial strength did not exhibit concentration dependence. At high essential oil concentration (>1000µg/ml), size of zone of inhibition was all <7mm. Developed TLC-DB separated the components and visualised the inhibition of bacterial growth on the plate surface where the active antimicrobials were determined to be the minor components, hydroxylated terpenes, rather than the dominant component, chamazulene.

Variability in the Essential Oil Composition of Achillea erba-rotta subsp. moschata (Wulfen) I. Richardson Growing in the Eastern Italian Alps.

Achillea erba-rotta subsp. moschata (Wulfen) I. Richardson is endemic of the Central Alps and distributed in several Italian Regions, where is used for its medicinal and aromatic properties. Nine wild populations of the species were characterized for their essential oil content and composition. In total 45 components were detected of which 40 were identified, accounting from 96.3 % to 98.8 % of the total oil. Monoterpenes represented the main class of compounds (from 84 % to 90.9 %), being cis-thujone (from 1.1 % to 48.4 %), camphor (from 1.8 % to 36.9 %), 1,8-cineole (from 4.9 % to 23.4 %), trans-thujone (from 2.2 % to 33.9 %) and p-cymene (from 1.8 % to 4.8 %) the most abundant ones. The relative amount of chamazulene, detected in some accessions, was here reported for the first time in this species. High variability in the essential oil composition resulted among the investigated accessions, which were grouped by multivariate analysis into four main clusters, in some cases according to their site of origin. Beyond their possible chemo-systematic significance, the obtained results represent useful indications for the selection of interesting chemotypes within the species, especially in the perspective of its future cultivation.

Essential oils from leaves of Vernonanthura montevidensis (Spreng.) H. Rob.: chemical profile and antimollicute potential.

Aiming to valorise the Atlantic Rainforest biodiversity in Santa Catarina, the chemical characterisation of the essential oils (EOs) from leaves of Vernonanthura montevidensis (Spreng.) H. Rob. is described for the first time. Fresh leaves collected in the year 2014 and 2015, were submitted to hydrodistillation to give pale blue EOs in yields of 0.21 and 0.19%, respectively. The EOs were characterised by GC-MS and GC-FID semi- and quantitative methods. The monoterpene ß-pinene was the major constituent in both samples reaching a maximum of 26.3%. The monoterpene α-pinene and the sesquiterpene ß-caryophyllene, were also among the major constituents in both samples. By means of the extracted ion chromatogram procedure, it was possible to detect chamazulene, which was associated with the pale blue colour of the essential oils. In the in vitro antimollicute assays, the essential oil was moderately active against Mycoplasma genitalium and M. pneumoniae with MIC values of 250 µg mL-1.

In vitro and in vivo biological activities of azulene derivatives with potential applications in medicine.

Azulene is an aromatic hydrocarbon that possesses a unique chemical structure and interesting biological properties. Azulene derivatives, including guaiazulene or chamazulene, occur in nature as components of many plants and mushrooms, such as Matricaria chamomilla, Artemisia absinthium, Achillea millefolium, and Lactarius indigo. Due to physicochemical properties, azulene and its derivatives have found many potential applications in technology, especially in optoelectronic devices. In medicine, the ingredients of these plants have been widely used for hundreds of years in antiallergic, antibacterial, and anti-inflammatory therapies. Herein, the applications of azulene, its derivatives and their conjugates with biologically active compounds are presented. The potential use of these compounds concerns various areas of medicine, including anti-inflammatory with peptic ulcers, antineoplastic with leukemia, antidiabetes, antiretroviral with HIV-1, antimicrobial, including antimicrobial photodynamic therapy, and antifungal.

Chamazulene-Rich Artemisia arborescens Essential Oils Affect the Cell Growth of Human Melanoma Cells.

Artemisia arborescens is an aromatic shrub whose essential oils are considered a potential source of molecules with industrial and pharmaceutical interest. The chemical profile of A. arborescens essential oils (EOs) was shown to be quite variable and various chemotypes have been identified. In this study, we compared the EOs composition of A. arborescens leaves and flowers collected from four different locations in Sicily. The EOs were assayed for their antiproliferative activity against A375 human malignant melanoma cells, also testing cell viability and cell membrane integrity. The evaluation of DNA fragmentation and caspase-3 activity assay was employed for the detection of apoptosis. The expression of Bcl-2, Bax, cleaved caspase-9, PTEN (Phosphatase and tensin homolog), Hsp70 (Heat Shock Protein 70 kilodaltons) and SOD (superoxide dismutase) proteins was evaluated by Western blot analysis. The levels of ROS and GSH were also analyzed. Results show that EOs presented significant differences in their composition, yield, and cytotoxic activity depending on the collection site. The chamazulene/camphor-rich EOs from plants collected in Acqua Calda (Lipari) resulted particularly active on melanoma cancer cells (IC50 values of 6.7 and 4.5 µg/mL), being able to trigger apoptotic death probably interfering with endogenous defense mechanisms. These oils may be considered as a natural resource of chamazulene, containing this compound up to 63%.

Hepatoprotective effects of chamazulene against alcohol-induced liver damage by alleviation of oxidative stress in rat models.

Liver injury and disease caused by alcohol is a common complication to human health worldwide. Chamazulene is a natural proazulene with antioxidant and anti-inflammatory properties. This study aims to investigate the hepatoprotective effects of chamazulene against ethanol-induced liver injury in rat models. Adult Wistar rats were orally treated with 50% v/v ethanol (8-12 mL/kg body weight [b.w.]) for 6 weeks to induce alcoholic liver injury. Chamazulene was administered orally to rats 1 h prior to ethanol administration at the doses of 25 and 50 mg/kg b.w. for 6 weeks. Silymarin, a commercial drug for hepatoprotection, was orally administered (50 mg/kg b.w.) for the positive control group. Chamazulene significantly reduced (p < 0.05) the levels of serum alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and malondialdehyde, whereas the levels of antioxidant enzymes (glutathione peroxidase, catalase, and superoxide dismutase) and reduced glutathione were significantly restored (p < 0.05) in contrast to the ethanol model group. The levels of pro-inflammatory cytokines (tumour necrosis factor-α and interleukin-6) were suppressed by chamazulene (p < 0.05) with relevance to ethanol-induced liver injury. Histopathological alterations were convincing in the chamazulene-treated groups, which showed protective effects against alcoholic liver injury. Chamazulene has a significant hepatoprotective effect against ethanol-induced liver injury through alleviation of oxidative stress and prevention of inflammation.

Chamazulene reverses osteoarthritic inflammation through regulation of matrix metalloproteinases (MMPs) and NF-kß pathway in in-vitro and in-vivo models.

This study was conducted to evaluate the protective effects of chamazulene against IL-1ß-induced rat primary chondrocytes and complete Freund's adjuvant (CFA)-induced osteoarthritic inflammation in rats. Oxidative stress markers, pro-inflammatory cytokines, and regulatory proteins were measured. Chamazulene significantly reverted (p < 0.05) the levels of lipid peroxidation and enhanced the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) enzymes against IL-1ß and CFA-induced oxidative stress. The levels of TNF-α and IL-6 were reduced (p < 0.05) in chamazulene treatment against IL-1ß and CFA-induced inflammation. Western blot analysis results on the expressions of MMP-3, MMP-9, p65 NF-kß, iNOS, and COX-2 showed chamazulene was able to protect the chondrocytes against IL-1ß-induced osteoarthritic inflammation. Histopathology of rat hind ankle showed chamazulene significantly protected against CFA-induced osteoarthritic inflammation. Therefore, chamazulene can be recommended as a therapeutic agent for clinical trials against osteoarthritic inflammation.

Chemical composition and evaluation of antinociceptive activity of the essential oil of Stevia serrata Cav. from Guatemala.

The composition and the antinociceptive activity of the essential oil of Stevia serrata Cav. from a population located in the west highlands of Guatemala were evaluated. A yield of 0.2% (w/w) of essential oil was obtained by hydrodistillation of the dried aerial parts of the plant. The essential oil analysed by GC-FID and GC-MS showed a high content of sesquiterpenoids, with chamazulene (60.1%) as the major component and 91.5% of the essential oil composition was identified. To evaluate antinociceptive activity in mice, the essential oil of S. serrata Cav. was administered as gavage, using three different doses. In the formalin test, the animals were pre-treated with oral doses of the essential oil before the administration of formalin. Oral administration of S. serrata Cav. essential oil produced a marked antinociceptive activity. Therefore, the plant could be domesticated as a source of essential oil rich in chamazulene for developing medicinal products.

Safety and efficacy of topical essential oil as steroid-sparing agent in the treatment of atopic dermatitis in a community outreach care program of New Era University second year medical students, randomized double blind placebo controlled trial

BACKGROUND@#The high rates of atopic dermatitis among children, treatment failures and treatment costs have created the search for new therapies to control flares of atopic dermatitis.@*OBJECTIVES@#We compared the efficacy and safety of topical essential oil (German Chamomile) versus topical steroids (hydrocortisone 1%) in controlling flares of atopic dermatitis.@*METHOD@#We randomly selected 60 children diagnosed of AD or children that qualified to the criteria of AD. They we’re randomly grouped into three. Twenty for Essential Oil (EO) group, twenty for Steroid group (SG) and Twenty for placebo (distilled water) group. They were advised to apply medicine kept in uniform brown plastic bottles 3x a day for 4 weeks. Data were recorded weekly using the EASI (Eczema Score Index) scoring. Other topical medications such as emollients and moisturizers were continued.@*RESULTS@#At week 4 control of flaring was achieved; 42% for EO group and 55% for steroid group. The differences in treatment effects were not statistically significant.@*CONCLUSION@#Essential oil was comparable in cure rate to mild topical steroid. Essential oil can be safe and affordable. However further study in a wider scale is recommended.

Chamazulene Attenuates ROS Levels in Bovine Aortic Endothelial Cells Exposed to High Glucose Concentrations and Hydrogen Peroxide.

Endothelial cells surround the lumen of blood vessels and modulate many physiological processes, including vascular tone, blood fluidity, inflammation, immunity and neovascularization. Many pathological conditions, including hyperglycemia, may alter endothelial function through oxidative stress, leading to impaired nitric oxide bioavailability and to the onset of an inflammatory state. As widely shown in the last decade, dietary intervention could represent a good strategy to control endothelial dysfunction and atherosclerosis. In particular, extensive research in the field of antioxidant natural derivatives has been conducted. In this study, we evaluated the capability of Chamazulene (Cham), an azulene compound from chamomile essential oil, to attenuate ROS levels in bovine aortic endothelial cells (BAECs) stressed with either high glucose or H2O2. Cell viability at different concentrations of Cham was evaluated through the WST-1 assay, while ROS production acutely induced by High Glucose (HG, 4.5 g/L) treatment or H2O2 (0.5 mM) for 3 h, was quantified with 2'-7'-Dichlorofluorescein diacetate (DCFH-DA) probe using confocal microscopy and flow cytometry. Our results showed a reduction in ROS produced after simultaneous treatment with High Glucose or H2O2 and Cham, thus suggesting an in vitro antioxidant activity of the compound. On the whole, this study shows for the first time the potential role of Cham as a scavenging molecule, suggesting its possible use to prevent the rise of endothelial ROS levels and the consequent vascular damage.

Efficacy of Compounds Isolated from the Essential Oil of Artemisia lavandulaefolia in Control of the Cigarette Beetle, Lasioderma serricorne.

To develop natural product resources to control cigarette beetles (Lasioderma serricorne), the essential oil from Artemisia lavandulaefolia (Compositae) was investigated. Oil was extracted by hydrodistillation of the above-ground portion of A. lavandulaefolia and analyzed using gas chromatography-mass spectrometer (GC-MS). Extracted essential oil and three compounds isolated from the oil were then evaluated in laboratory assays to determine the fumigant, contact, and repellent efficacy against the stored-products' pest, L. serricorne. The bioactive constituents from the oil extracts were identified as chamazulene (40.4%), 1,8-cineole (16.0%), and ß-caryophyllene (11.5%). In the insecticidal activity assay, the adults of L. serricorne were susceptible to fumigant action of the essential oil and 1,8-cineole, with LC50 values of 31.81 and 5.18 mg/L air. The essential oil, 1,8-cineole, chamazulene, and ß-caryophyllene exhibited contact toxicity with LD50 values of 13.51, 15.58, 15.18 and 35.52 µg/adult, respectively. During the repellency test, the essential oil and chamazulene had repellency approximating the positive control. The results indicated that chamazulene was abundant in A. lavandulaefolia essential oil and was toxic to cigarette beetles.

Pharmacodynamic effects of main chemical components of Lindera aggregata based on network pharmacology / 中草药

Objective To predict the pharmacological effect and targets of main chemical components of Lindera aggregata, and construct the multi-target network. Methods The potential targets and pathways of linderene acetate, isocembrol, laurolitsine, β-humulene, chamazulene, laurotetanine, and lindestrenolide, selected as the representative compounds of oils, alkaloids, and furan sesquiterpene lactones from Linderae Radix, were predicted by methods of network pharmacology. The pharmacodynamic effects of main chemical constituents of L. aggregata was analyzed by data integration. Results The in silico prediction results showed that seven compounds of L. aggregata affected 20 related pathways through 40 potential targets. The pathways were involved in several links including inflammatory, analgesic, gastrointestinal movement regulation, anti-oxidation, antitumor, liver injury protection, and immunoregulation. The various components showed common targets, pathways, and pharmacodynamic effects and had different emphases. Conclusion The pathways related to L. aggregata oils, alkaloids, and furan sesquiterpene lactones were connected by the common targets, showing the synergistic effect of different compounds by acting on multi-targets and multi-pathways. This study provides references for systematic exploration on the pharmacological actions and mechanisms of L. aggregata.

Separation of bioactive chamazulene from chamomile extract using metal-organic framework.

Isolation of bioactive compounds from extracts of pharmaceutical plant is very important. In this work, copper benzene-1,3,5-tricarboxylate metal organic framework (Cu-BTC MOF) has been synthesized. It is used in separating of chamazulene from chamomile extract. The Cu-BTC MOF not only shows good chamazulene adsorption but also maintains good desorption properties. However, the research on this field is still new and the maturation of novel MOFs or the enhancements of known ones are required.The chamomile extract obtained after each stage of the treatments was carefully characterized by thin-layer chromatography (TLC), Fourier-transform infrared spectroscopy (FTIR), UV-vis spectrometry and gas chromatography-mass spectrometry (GC-MS). The morphology and the crystallinity of Cu-BTC MOF were investigated using scanning electron microscopy (SEM) and powder X-ray diffraction (PXRD), respectively. Breakthrough experiments in a column was investigated and the data was fitted with Bohart-Adams model. Monte Carlo simulation was conducted to investigate the preferential adsorption sites of Cu-BTC for chamazulene molecules.

Increase of Chamazulene and α-Bisabolol Contents of the Essential Oil of German Chamomile (Matricaria chamomilla L.) Using Salicylic Acid Treatments under Normal and Heat Stress Conditions.

The chamazulene and α-(-)-bisabolol contents and quality of the chamomile oil are affected by genetic background and environmental conditions. Salicylic acid (SA), as a signaling molecule, plays a significant role in the plant physiological processes. The aim of this study was to evaluate the chemical profile, quantity, and improve the essential oil quality as a consequence of the increase of chamazulene and α-(-)-bisabol using salicylic acid under normal and heat stress conditions by the gas chromatography-mass spectrometry (GC-MS) technique. The factorial experiments were carried out during the 2011-2012 hot season using a randomized complete block design with three replications. The factors include four salicylic acid concentrations (0 (control), 10, 25 and 100 mg·L-1), and three chamomile cultivars (Bushehr, Bona, Bodegold) were sown on two different planting dates under field conditions. Fourteen compounds were identified from the extracted oil of the samples treated with salicylic acid under normal and heat stress conditions. The major identified oil compositions from chamomile cultivars treated with salicylic acid were chamazulene, α-(-)-bisabolol, bisabolone oxide, ß-farnesene, en-yn-dicycloether, and bisabolol oxide A and B. Analysis of variance showed that the simple effects (environmental conditions, cultivar and salicylic acid) and their interaction were significant on all identified compounds, but the environmental conditions had no significant effect on bisabolol oxide A. The greatest amount of chamazulene obtained was 6.66% at the concentration of 10 mg·L-1 SA for the Bona cultivar under heat stress conditions, whereas the highest α-(-)-bisabolol amount attained was 3.41% at the concentration of 100 mg·L-1 SA for the Bona cultivar under normal conditions. The results demonstrated that the application of exogenous salicylic acid increases the quantity and essential oil quality as a consequence of the increase of chamazulene and α-(-)-bisabolol under normal and heat stress conditions.

Chemical composition of the essential oil from Thapsia garganica L. (Apiaceae) grown wild in Sicily and its antimicrobial activity.

In this study, the chemical composition of the essential oil from flowers and leaves of Thapsia garganica L. collected in Sicily was evaluated by GC and GC-MS. The main components of T. garganica flower oil (T.f.) were chamazulene (58.3%), humulene oxide II (9.0%), tricosane (8.2%) and pentacosane (8.2%). Also the oil from leaves (T.l.) was characterised by high content of chamazulene (49.2%). Other abundant metabolites were 1,4-dimethylazulene (18.5%), (E)-phytol (6.3%) and neophytadiene (5.1%). The comparison with other studied oils of genus Thapsia is discussed. Antimicrobial activity against several micro-organisms, including some ones infesting historical art craft, was also determined.

Revisited anti-inflammatory activity of matricine in vitro: Comparison with chamazulene.

The proazulene matricine (1) is present in chamomile flower heads and has been proven to exhibit strong in vivo anti-inflammatory activity. In contrast to other secondary metabolites in chamomile preparations like its degradation product chamazulene (2), no plausible targets have been found to explain this activity. Therefore we revisited 1 regarding its in vitro anti-inflammatory activity in cellular and molecular studies. Using ICAM-1 as a marker for NF-κB activation, it was shown that ICAM-1 protein expression induced by TNF-α and LPS, but not by IFN-γ, was remarkably inhibited by 1 in endothelial cells (HMEC-1). Inhibition was concentration-dependent in a micromolar range (10-75 µM) and did not involve cytotoxic effects. At 75 µM expression of the adhesion molecule ICAM-1 was down to 52.7 ± 3.3% and 20.4 ± 1.8% of control in TNF-α and LPS-stimulated HMEC-1, respectively. In contrast, 2 showed no activity. Quantitative RT-PCR experiments revealed that TNF-α-induced expression of the ICAM-1 gene was also reduced by 1 in a concentration-dependent manner, reaching 32.3 ± 6.2% of control at 100 µM matricine. Additional functional assays (NF-κB promotor activity and cytoplasm to nucleus translocation) confirmed the inhibitory effect of 1 on NF-κB signaling. Despite the fact that 1 lacks an α,ß-unsaturated carbonyl and is thus not able to act via a Michael reaction with electron rich SH groups of functional biological molecules, data gave strong evidence that 1 inhibits NF-κB transcriptional activity in endothelial cells by an hitherto unknown mechanism and this may contribute to its well-known anti-inflammatory activity in vivo.

Antioxidant and radical scavenging activities of chamazulene.

Essential oils (EOs) of chamomile contain several bioactive compounds, including monoterpenes, sesquiterpenes, triterpenes and fatty acids. Hydrodistillation of chamomile EO induces the formation of chamazulene, a bioactive compound. Chamazulene was isolated from the EO by column chromatography. The total antioxidant capacity confirmed a higher antioxidant activity of chamazulene (IC50 = 6.4 µg mL(- 1)) than of ascorbic acid (IC50 = 12.8 µg mL(- 1)), α-tocopherol (IC50 = 20.5 µg mL(- 1)) and of butylated hydroxytoluene (BHT) (IC50 = 30.8 µg mL(- 1)). Chamazulene was unable to react with DPPH√. However, when chamazulene was assayed with ABTS√, a strong and significantly (P < 0.05) higher free radical scavenging activity was observed (IC50 = 3.7 µg mL(- 1)), with respect to BHT (IC50 = 6.2 µg mL(- 1)) and α-tocopherol (IC50 = 11.5 µg mL(- 1)). The results of this work show that chamazulene is an important factor for the antioxidant power of chamomile oil.