Antioxidant Potential Of Essential Oil Research Articles

Deciphering the Antibiofilm, Antibacterial, and Antioxidant Potential of Essential Oil from Indian Garlic and its Phytocompounds Against Foodborne Pathogens.

Garlic (Allium sativum L.), particularly its volatile essential oil, is widely recognized for medicinal properties. We have evaluated the efficacy of Indian Garlic Essential Oil (GEO) for antimicrobial and antibiofilm activity and its bioactive constituents. Allyl sulfur-rich compounds were identified as predominant phytochemicals in GEO, constituting 96.51% of total volatile oils, with 38% Diallyl trisulphide (DTS) as most abundant. GEO exhibited significant antibacterial activity against eleven bacteria, including three drug-resistant strains with minimum inhibitory concentrations (MICs) ranging from 78 to 1250µg/mL. In bacterial growth kinetic assay GEO effectively inhibited growth of all tested strains at its ½ MIC. Antibiofilm activity was evident against two important human pathogens, S. aureus and P. aeruginosa. Mechanistic studies demonstrated that GEO disrupts bacterial cell membranes, leading to the release of nucleic acids, proteins, and reactive oxygen species. Additionally, GEO demonstrated potent antioxidant activity at IC50 31.18mg/mL, while its isolated constituents, Diallyl disulphide (DDS) and Diallyl trisulphide (DTS), showed effective antibacterial activity ranging from 125 to 500µg/mL and 250-1000µg/mL respectively. Overall, GEO displayed promising antimicrobial and antibiofilm activity against enteric bacteria, suggesting its potential application in the food industry.

Chemical components and antioxidant potential of essential oil of Rhanterium epapposum growing in sandy habitat in Saudi Arabia: In silico study on cytochrome P450 1A1 and xanthine oxidase

Rhanterium epapposum Oliv. (Family: Asteraceae) is a common plant in Saudi Arabia, possessing a variety of traditional uses. The current targets were studying the comparative chemical profile and antioxidant of the essential oil (EO) of R. epapposum collected from a sandy habitat at Qareenah, Riyadh, Saudi Arabia. The EO profiling was constructed via gas chromatography-mass spectrometry (GC-MS) and GC-flame ionization detection (GC-FID). Forty-eight compounds were found, including monoterpenes (hydrocarbons 3.25% and oxygenated 48.64%), sesquiterpenes (hydrocarbons 12.64 % and oxygenated 32.38%), which are the backbone of the oil along with a minor of other non-terpenoid compounds (1.31%). Linalool (18.02%), α-eudesmol (11.98%), trans-sesquisabinene hydrate (11.63%), aromadendrene oxide-(1) (7.68%), nerol (6.88%), and α-terpineol (5.01%) were identified as the dominant components. The EO was evaluated for its antioxidant activity using in vitro DPPH, ABTS, and FRAP methods. The results demonstrated that R. epapposum EO possesses a dosage-dependent ability for antioxidant scavenging activity as per all three techniques. This EO exhibited IC50 values of 517.59, 350.24, and 713.72 μg/mL for the DPPH, ABTS, and FRAP, respectively, through the comparison with the ascorbic acid with respective values of 36.10, 26.12, and 44.58 μg/mL. The main compounds were subjected to docking analysis on cytochrome P450 1A1 and xanthine oxidase. All evaluated compounds exhibited good binding affinities especially α-eudesmol and linalool for both enzymes, respectively. The current research confirmed the potent free radical scavenging properties of R. epapposum EO. More research on the antioxidant content of this oil and/or its primary constituents in pure form on the two enzymes, cytochrome P450 1A1 and xanthine oxidase, is proposed to develop a better understanding of the oxidative action routes in vivo and in vitro.

Chemical characterization and antioxidant activities of essential oil of Ficus elastica Roxb. ex Hornem. leaves

The present study investigates the chemical constituents and antioxidant potential of essential oils extracted from Ficus elastica. The essential oils were obtained through steam distillation and were subjected to gas chromatography-mass spectrometry (GC-MS) analysis to determine their constituents representing 100% of the total peak areas. The analysis revealed the presence of 34 compounds. Among these compounds, Caryophyllene was found to be the major constituent, accounting for 50.57% of the total percentage area. Among other identified major compounds include γ-Muurolene (8.19%), camphene (5.69%), Heptacosane (2.61%), and Heneicosane (2.60%). Furthermore, the antioxidant potential of Ficus elastica essential oil was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide radical scavenging methods. The results indicated that F. elastica’s essential oil exhibited significant radical scavenging activity when compared to the standard antioxidant, Ascorbic acid. For the highest concentration tested (10 μL/mL), the DPPH scavenging inhibition percentage was 45.26% for F. elastica and 90.40% for Ascorbic acid. Similarly, the hydrogen peroxide scavenging activity at 10 μL/mL was found to be 74.90% for F. elastica and 90.12% for Ascorbic acid. Additionally, the essential oils demonstrated high radical scavenging and chelating activity. The quantitative DPPH and hydrogen peroxide assays indicate the potent antioxidant activity of F. elastica essential oil, making it a promising candidate for further biological and chemical analysis. The isolation of therapeutically active compounds from these essential oils can be pursued, considering their potential role in the management and treatment of various diseases.

Composition and antioxidant potential of essential oil of Geranium macrorrhizum L. from different regions of Bulgaria

The common geranium (Geranium macrorrhizum L.) is the economically most important species of the genus Geranium, and is highly valued for its fragrance and medicinal properties. Object of the present study is the essential oil (EO) prepared by hydro-distillation of aerial parts and rhizomes of common geranium from four floristic regions of the country. Its quality was determined by GC-MS analysis. The antioxidant potential of G. macrorrhizum was evaluated by the DPPH method. Forty-two compounds were identified. In the EOs from the aerial parts, the compound in the most quantity was the sesquiterpene germacrone (from 51.41 to 62.58 %). In the EOs from the rhizomes, this compound was only 5.80-8.94%. The most common ingredient of the rhizome EO was another sesquiterpene: cis-β-elemenone in a quantity from 45.20 to 50.64%. Other nine compounds were present only in the rhizome samples, among which the sesquiterpene globulol was found in good quantities: 15.71 – 15.90%. Monoterpenes like α-terpinene and phellandrene, and sesquiterpenes like eudesm-11-en-4α,6α-diol and eudesm-7(11)-en-4-ol acetate were detected only in some EOs from the aerial parts. The radical scavenging potentials of the EOs were from 33.15 to 41.79 µmol TE/100 µg EO, the rhizome samples showing weaker antioxidant potential compared to the aerial parts. Pearson correlation coefficients between the main ingredients of the EOs from the aerial parts and the radical scavenging potential pointed to the strongest impact of germacrene A on thе antioxidant value. The large differences in the results are due to the different agro-ecological conditions under which the plants were grown.

Phytochemical study on the essential oils of Callitris glaucophylla Joy Thomps. & L.A.S. Johnson, and assessment of their antioxidant, anti-enzymatic and allelopathic effects

Callitris glaucophylla Joy Thomps. & L.A.S. Johnson is a coniferous forest species of the Cupressaceae family native to Australia. This species is rich in essential oils (EOs) but few studies about variability and biological activity of these EOs are available in the literature. The purpose of this study was to evaluate the variability of production of C. glaucophylla EOs in relation to the different plant parts (needles, cones and stems) and to investigate their antioxidant, anti-enzymatic and herbicidal properties. EOs were obtained by hydro distillation and analyzed by GC and GC-MS. The antioxidant potential of EOs was assessed by ABTS, FRAP and DPPH assays, their phytotoxic activities were evaluated against germination and shoots and radical growth of Sinapis arvensis, Trifolium campestre, Lepidium sativum and Lolium rigidum. The EOs were evaluated for their possible anti-enzymatic effects with spectrophotometric assay. EOs resulted rich in monoterpenes hydrocarbons (61.04–77.82 %) and oxygenated monoterpenes (19.52–25.26 %). The main compounds were α-pinene as major compound in all plant parts (36.99–59.84 %), 1,8-cineole (19.88 % in stems) and limonene (18.94 % in needles). Herbicidal assays showed that all EOs have remarkable and significant phytotoxicity towards germination, roots, and aerial parts growth of the tested plants, depending on the EO, the doses and tested species. The EOs showed significant free radical scavenging potential and resulted more active against cholinesterases than α-glucosidase and α-amylase. The data obtained constitute an important contribution in selecting and valorizing appropriate forestry tree biomass as sources of antioxidant and phytotoxic molecules for sustainable application in food preservation and weeds control. The activities against the tested enzymes confirmed a possible use of these EOs as natural pesticides.

Antibacterial and Antioxidant Potential of Essential Oil of Eucalyptus camaldulensis and Its Major Components

Antibacterial and Antioxidant Potential of Essential Oil of Eucalyptus camaldulensis and Its Major Components

Chemical composition, in vitro antioxidant and α-amylase inhibitory activities of rhizomes essential oil and nutrient components from rhizomes powder of Curcuma caesia Roxb. (black turmeric) collected from Garhwal region of Uttrakhand, India

The current study was performed to analyse the phytochemical composition, in vitro antioxidant and α-amylase inhibitory activities of the essential oil separated from Curcuma caesia Roxb. (black turmeric) rhizomes. The essential oil of Curcuma caesia (C. caesia) rhizomes was separated by hydrodistillation technique. Further, essential oil was subjected to GC-MS and FTIR analysis for chemical analysis. Additionally, rhizome powder was investigated for nutritional content using standard reported methods. Subsequently, antioxidant potential of essential oil was analysed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay followed by α-amylase inhibitory assay. Results of the study suggested the presence of various important compound viz. curzerenone (29.78%), α-Bulnesene (14.43%), eucalyptol (13.32%), curzerene (4.88%), and camphor (4.71%), respectively. Similarly, potent antioxidant and α-amylase inhibitory activities were observed in oil. It was concluded from the present work that essential oil of C. caesia rhizomes contains many therapeutic useful aromatic bioactive and nutritional components. Additionally, essential oil of C. caesia rhizomes exhibits profound antioxidant and α-amylase inhibitory activities.

Antioxidant Activities of Essential Oils and Their Major Components in Scavenging Free Radicals, Inhibiting Lipid Oxidation and Reducing Cellular Oxidative Stress.

Antioxidant activities of five essential oils (cinnamon, thyme, clove, lavender and peppermint oils) and their major components (eugenol, thymol, linalool, and menthol) were evaluated on scavenging DPPH (2,2-diphenyl-1 picrylhydrazyl) free radicals, inhibiting polyunsaturated fatty acid oxidation in fish oil emulsion (FOE), and reducing oxidative stress in human red blood cells (RBC). The essential oils from cinnamon, thyme, clove and their main components, eugenol and thymol, exhibited the highest antioxidant activity in the FOE and RBC systems. It was found that the antioxidant activity of essential oils was positively correlated to the content of eugenol and thymol, while lavender and peppermint oils and their main components, linalool and menthol, had very low antioxidant activity. Compared with scavenging DPPH free radical activity, the antioxidant activity in FOE and RBC systems could better reflect the actual antioxidant potential of essential oil in preventing lipid oxidation and reducing oxidative stress in biological system.

Chemical composition, antioxidant, and antimicrobial activities of P. roxburghii oleoresin essential oils extracted by steam distillation, superheated steam, and supercritical fluid CO2 extraction.

Pinus roxburghii is a rich source of high-quality oleoresin that is composed of resin acids and essential oil (EO). The present research work was planned to study and compare the yield, biological activities, and chemical profiling of P. roxburghii oleoresin EOs extracted through various green extraction methods. Steam distillation (SD), supercritical fluid extraction, and superheated SD (SHSD) at different temperatures (120, 140, and 160°C) were employed to extract EOs from P. roxburghii oleoresin. Antioxidant potential of EOs was determined by total antioxidant content/ferric-reducing antioxidant power (FRAP), 2,2-diphenyl-1-picrylhydrazyl (DPPH)-free radical scavenging activity (DPPH-FRSA), hydrogen peroxide scavenging assays, and percentage inhibition in linoleic acid. Antimicrobial activity of EOs was determined by resazurin microtiter-plate, disc diffusion, and micro-dilution broth susceptibility assays. Gas chromatography-mass spectrometry was used to determine the chemical composition of EOs. It was observed that extraction methods significantly affected the yield, biological activities, and chemical composition of EOs. The maximum yield (19.92%) was found in EO extracted by SHSD at 160°C. EO extracted by SHSD at 120°C showed the highest DPPH-FRSA (63.33%±0.47%), linoleic acid oxidation inhibition (96.55%±1.71%), hydrogen peroxide scavenging activity (59.42%±0.32%), and total antioxidant contents/FRAP (134.49%±1.34mg/L of gallic acid equivalent). The antimicrobial activity results showed that superheated steam-extracted EO of 120°C revealed the highest antifungal and antibacterial activity. It is concluded that SHSD is an alternative and effective technique for the extraction of oleoresins EO that improves the EO yield and biological activities. Further research on optimization and experimental parameters for the extraction of P. roxburghii oleoresin EO by SHSD is required.

Potential of essential oils for protection of Couscous against Aspergillus flavus and aflatoxin B1 contamination

Our study was aimed to evaluate antifungal, antiaflatoxin, and antioxidant potential of Mentha pulegium, Myrtus communis, and Mentha piperita essential oils (EOs). The EOs showed efficacy as a couscous preservative. A total of 387 fungal species were isolated from Couscous samples, with Aspergillus flavus BN (20) which is identified as the highest aflatoxin producer. The minimum inhibitory concentration (MIC) of M. pulegium and M. communis EOs against the toxigenic strain of A. flavus BN (20) determined to be 4.00 μL/mL, whereas the MIC of M. piperita was 3.50 μL/mL. The EOs inhibited the aflatoxin B 1 production at lower concentrations. The EOs showed fungitoxicity against wide-ranging of fungi and high antioxidant activity. The IC 50 value of the oils ranged between 3.27 and 4.31 μL/mL. EOs may be able to contribute preservation of food commodities against quantitative and qualitative losses. During fumigation assays in Algerian traditional food system (Couscous), the three EOs showed protection of Couscous from A. flavus contamination indicating their efficacy as sustainable fumigant in food systems. • 1.-Antifungal, antiaflatoxin, and antioxidant potential of essential oils (EOs) was studied. • 2.-The EOs inhibited the aflatoxin B 1 production at lower concentrations. • 3.-EOs showed fungitoxicity against a broad spectrum of fungi and strong antioxidant activity. • 4.-EOs may be able to provide protection of food commodities against losses. • 5.- EOs showed protection of couscous from A. flavus contamination.

Chemical Composition and Biological Activities of Eucalyptus globulus Essential Oil.

Eucalyptus globulus essential oil (EGEO) is considered as a potential source of bioactive compounds with significant biological activity. The aim of this study was to analyze the chemical composition of EGEO, in vitro and in situ antimicrobial activity, antibiofilm activity, antioxidant activity, and insecticidal activity. The chemical composition was identified using gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). The main components of EGEO were 1,8-cineole (63.1%), p-cimene (7.7%), a-pinene (7.3%), and a-limonene (6.9%). Up to 99.2% of monoterpenes were present. The antioxidant potential of essential oil and results indicate that 10 μL of this sample can neutralize 55.44 ± 0.99% of ABTS•+, which is equivalent to 3.22 ± 0.01 TEAC. Antimicrobial activity was determined via two methods: disk diffusion and minimum inhibitory concentration. The best antimicrobial activity was shown against C. albicans (14.00 ± 1.00 mm) and microscopic fungi (11.00 ± 0.00 mm-12.33 ± 0.58 mm). The minimum inhibitory concentration showed the best results against C. tropicalis (MIC 50 2.93 µL/mL, MIC 90 3.17 µL/mL). The antibiofilm activity of EGEO against biofilm-forming P. flourescens was also confirmed in this study. The antimicrobial activity in situ, i.e., in the vapor phase, was significantly stronger than in the contact application. Insecticidal activity was also tested and at concentrations of 100%, 50%, and 25%; the EGEO killed 100% of O. lavaterae individuals. EGEO was comprehensively investigated in this study and information regarding the biological activities and chemical composition of the essential oil of Eucalyptus globulus was expanded.

Chemical Composition and Biological Activity of Guarea cedrata (A. Chev.) Pellegr. Leaf and Root Bark Essential Oil

Aims: This study aims, on the one hand, to establish the chemical composition and to evaluate the antioxidant potential of essential oils (EO) of Guarea cedrata leaves and root bark, and on the other hand, to determine the antimicrobial activity of the leaf EO.
 Methodology: The EOs were analyzed by a combination of GC (Ir), GC-MS and 13C NMR. The antibacterial and antifungal activity of the essential oils was determined and then the antioxidant activity was also evaluated.
 Results: 40 hydrocarbon (19.8%) and oxygenated (73.3%) sesquiterpenes were identified from root bark EO, representing 93.1% of the total composition, and 55 compounds were identified from leaf EO, representing 91.5% of the total composition, with 58.1% sesquiterpene hydrocarbons, 32.4% oxygenated sesquiterpenes and 1.0% hydrocarbon monoterpenes. An evaluation of the antioxidant potential of these EOs revealed moderate free radical scavenging activity of G. cedrata leaf EO compared to quercetin. Leaf EO tested on bacteria and yeast showed bacteriostatic activity against bacterial strains of Escherichia coli, Salmonella typhimurium, Bacillus subtilis and Candida albicans at a concentration of 6.3 mg/ml and bactericidal activity at a concentration of 50 mg/ml.
 Conclusion: This study highlighted the chemical composition, the antiradical and biological activity of the essential oils of two organs (leaf and trunk bark) organs of G. cedrata.

Chemical Composition, Antifungal, Antioxidant and Cytotoxic Potential of Apium graveolens L. (Celery) Leaves Essential Oil Collected from Nainital, Uttarakhand

Essential oils (EOs) extracted from aromatic plants are a potential source of several bioactive compounds. In the present study, hydro-distillation of Apium graveolens essential oil (AG-EO) was carried out and its chemical constituents were analyzed using Gas Chromatography (GC) and Gas Chromatography-Mass spectrometry (GC/MS) followed by examination of its antifungal, antioxidant, and cytotoxic potential against human breast cancer cells, MDA-MB-231. Analysis of EO resulted in the identification of nineteen (19) compounds majorly in 1,2-diphenyl-1,2-ethanediol (65.2%), 3-butyl phthalide (9.1%), limonene (6.4%), 1,1-dimethyl-1,2,3,5,7,8,9,9a-octahydro-benzocyclohepten-6-one (5.6%). Further, antifungal activity of A. graveolens EO (AG-EO) against three soil borne phytopathogenic fungal strains namely Fusarium oxysporum, Curvularia lunata, and Sclerotinia sclerotiorum showed significant mycelial growth inhibition at a concentration of 500 μg/mL with IC50 value ranging between 966-220.76 μg/mL. The antioxidant potential of EO was evaluated using dedicated spectrophotometric assays such as FRAP and DPPH. Results revealed the free radical scavenging potential of AG-EO with the value of 7.71±0.04 mM AAE/100g (for DPPH assay) and 8.31±0.03 mM AAE/100g (for FRAP assay). Additionally, the percentage of cell survival of MDA-MD-231 human breast cancer cells after treatment with EO was about 68% at 24h showing the cytotoxic effect of AG-EO against breast cancer cells whereas for non-malignant control HEK 293T cells it was about 83%. The present study indicated that the antioxidant, antifungal, and cytotoxic potential of AG-EO, a natural source of bioactive compounds, could be employed in the food, pharmaceuticals, agriculture, and cosmetics industries. However, further evaluations on animal models and clinical studies are warranted.

Antioxidant potential of essential oil from Phoenix dactylifera (L.) seed

Oxidative stress has been implicated in the initiation and progression of a plethora of diseases including atherosclerosis, diabetes mellitus, rheumatoid arthritis, neurodegenerative diseases, cardiovascular diseases and cancer. Due to the toxic and mutagenic side effects of some synthetic antioxidant compounds, intense interest is recently converged on natural antioxidants. This study therefore aimed at evaluating the antioxidant potential of essential oil extracted from Phoenix dactylifera seed. Phoenix dactylifera seed essential oil (PDEO) was extracted via steam-distillation technique. The antioxidant activity of the essential oil was assessed by radical scavenging, lipid peroxidation and reduction power assays. From the results obtained in this study, P. dactylifera essential oil showed significant concentration dependent antioxidant potential with maximum activity at 500 µg/ml viz: DPPH radical scavenging (76.24 ± 0.12 %), ABTS radical scavenging (68.97 ± 0.36 %), Nitric oxide radical scavenging (67.86 ± 0.16 %), Hydroxyl radical scavenging (68.70 ± 0.26 %), Fe2+ chelating ability (66.74 ± 0.25 %), Ferric reducing antioxidant power (262.29 ± 0.253 mMol FeSO4/g) and inhibition of lipid peroxidation (67.78 ± 0.29 %). Findings from this study revealed that essential oil from Phoenix dactylifera seed elicits substantial antioxidant activity and may serve as a veritable pharmacological candidate towards prevention of free radical related pathological damages.

Antioxidant potential of essential oil from Phoenix dactylifera (L.) seed

Antioxidant potential of essential oil from Phoenix dactylifera (L.) seed

Comparative analysis of chemical profiles and antioxidant activities of essential oils obtained from species of Lippia L. by chemometrics

Due to the importance of diseases associated with oxidative stress, the search for natural antioxidants proves to be essential. This work aimed to compare the chemical composition and antioxidant potential of essential oils from the genus Lippia L. through chemometric analysis. The essential oils were characterized by gas chromatography coupled with mass spectrometry. Antioxidant potentials were determined by DPPH, ABTS, Deoxyribose and β-carotene protection, Iron chelation and reduction methods. All data were related by multivariate analyzes. Essential oils showed low similar chemical compositions and no statistically significant relationship. These showed relevant antioxidant activity, especially for L. sidoides that obtained IC50 of 5.22 ± 0.08 µg/mL in ABTS capture. Multivariate analyzes showed the effectiveness of L. alba compounds to DPPH scavenging, Fe3+ reduction and β-carotene protection, and L. gracilis components to deoxyribose protect. Thus, studies proving the antioxidant potential of Lippia compounds against oxidative stress and their use in food conservation are fundamental.

Chemical Composition, Antioxidant and Antibacterial Activity of Two Different Essential Oils Against Mastitis Associated Pathogens

Abstract Mastitis is one of the most common and costly diseases affecting dairy cows worldwide. Since antibiotic resistance has become a global threat to both animal and human health, it is becoming more urgent to continuously search for new therapeutical alternatives for the control and treatment of bovine mastitis. Hence, our research aimed to test the therapeutic use of two essential oils (EOs) based on their chemical composition, antibacterial and antioxidant potential. The present study was conducted by collecting milk samples from the cows diagnosed with clinical or subclinical mastitis with the aim of isolating and identifying bacterial strains. The antioxidant potential of essential oils of Menthae piperitae (MP) and Melissa officinalis (MO) was evaluated in several in vitro assays. In the MP EO, a total of 38 compounds were identified, with menthol as the dominant compound, whereas in MO EO 51 compounds were identified. Furthermore, the values of minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) have been used to quantitatively measure the antibacterial activity of each essential oil. In accordance with which, MP EO samples exhibited a higher degree of antibacterial activity than MO EO. Thus, EOs have been shown to be promising alternatives to antibiotics because of their availability, biodegradability, and lower risk of side effects as compared with conventional, antimicrobial treatment. Nevertheless, further clinical studies are needed to test the potential role of EOs in treating mastitis in dairy cows.

Chemical Composition and Antioxidant Potential of Essential Oils from Peels of Four Citrus Species

Essential oils were isolated from the dried peels of Citrus limon, Citrus sinensis, Citrus auratifolia and Citrus reticulata using hydrodistillation method and were characterized using Gas Chromatography-Mass Spectrometry, while DPPH scavenging analysis was used to determine the antioxidant potentials of the oils. The hydrodistillation of the peels afforded oil in the yield of 0.61, 0.42, 0.72 and 0.52 (% w/w) for C. limon, C. auratifolia, C. sinensis and C. reticulate respectively. Analyses of the oils revealed the presence of monoterpenoids, sesquiterpenoids and non-terpenes. A total of 19, 25, 16 and 21 compounds were identified in the peels essential oils C. limon, C. auratifolia, C. sinensis and C. reticulata respectively. D-limonene, with the percentage composition of 84.9%, 44.6%, 91.8% and 82.4% in C. limon, C. auratifolia, C. sinensis and C. reticulata respectively was the most predominant compound. All the citrus species peels essential oils showed antioxidant activity of scavenging DPPH with IC50 of 27.29, 28.67, 32.0 and 33.0 μg/ml for C. limon, C. auratifolia, C. sinensis and C. reticulata respectively. The oils were of d-limonene chemotype and can thus be candidates for antioxidant drugs.

Yield and In Vitro Antioxidant Potential of Essential Oil from Aerva javanica (Burm. f.) Juss. ex Schul. Flower with Special Emphasis on Seasonal Changes.

The essential oil (EO) of the desert cotton (Aerva javanica (Burm. f.) Juss. ex Schul.) was extracted by hydrodistillation, from A. javanica flowers growing in the sandy soils of the United Arab Emirates (UAE) wild desert. The influence of seasonal variation on flowers’ EO yield was studied. The flowers’ EO yield obtained from spring samples (0.011%) was significantly the highest followed by early summer (0.009%), winter (0.007%), and autumn samples (0.006%), respectively. The flowers’ EO antioxidant analysis were tested by DPPH, FRAP and ABTS assays (in vitro). Results proved that A. javanica flowers’ EO, isolated during the four seasons, is a good source of natural bioactive antioxidants. Based on the three tested assays, the highest antioxidant activity was recorded in the spring. Testing of the chemical composition of the flowers’ EO was conducted for the season with the highest yield and the best antioxidant performance, recorded in spring, by a combination of gas chromatograph (GC) and gas chromatograph-mass spectrometer (GC-MS). This led to the identification of 29 volatile components, in which the flowers’ oil was characterized by angustione as a major compound. Photos by scanning electron microscope (SEM) showed prominent availability of star-shaped trichomes in the epidermis of the flowers.

Antioxidant potential, GC/MS and headspace GC/MS analysis of essential oils isolated from the roots, stems and aerial parts of Nepeta leucophylla

In the present study headspace GC/MS and GC/MS analysis of essential oils isolated from the roots, stems and aerial (inflorescence and leaves) parts of Nepeta leucophylla was carried out. The essential oils were isolated using Clevenger apparatus by hydro-distillation method. The isolated essential oils were also screened for its total polyphenolic content (TPC) and antioxidant potential using the ferric reducing antioxidant power (FRAP), total antioxidant capacity (TAC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The headspace GC/MS and GC/MS analysis of different parts and essential oils of N. leucophylla revealed the presence of monoterpene hydrocarbons, sesquiterpene hydrocarbons, oxygenated monoterpene hydrocarbons, oxygenated sesquiterpenes hydrocarbons, oxygenated diterpene hydrocarbons and phenolic diterpene hydrocarbons as major classes of volatile constituents. Caryophyllene, germacrene D, α-phellandrene, α-pinene, abieta-9(11),8(14),12-trien-12-ol, α-selinene, viridiflorol, totarol, α-terpinene, δ-cadinene are key volatile secondary metabolites identified in different parts of N. leucophylla and its essential oils using headspace GC/MS and GC/MS analysis. All the essential oils had similar TPC values. Further, the antioxidant potential of essential oil isolated from aerial parts was higher than that of roots and stems essential oil in case of all the assays, but the antioxidant potential of both essential oils is less than that of standard used. Furthermore, the correlation among TPC values and different antioxidant assays was also evaluated. The existing results of volatile phytoconstituents and antioxidant potential of essential oils suggest that the N. leucophylla have promising potential to be used in aroma, food and pharmaceutical industries.