The in vitro antioxidant and antimicrobial activities of the essential oil and methanol extracts of Achillea biebersteini Afan. (Asteraceae)

The essential oil and methanol extracts from A. biebersteinii Afan. (Asteraceae) were evaluated for their antimicrobial and antioxidant activities in vitro. The oil showed stronger antimicrobial activity than the extracts. Their antioxidant features were also evaluated using diphenyl-1-picrylhydrazyl (DPPH), inhibition of superoxide and hydroxyl radicals and inhibition of the lipid peroxidation assays. Particularly, polar subfraction of the methanol extract showed antioxidant activity. The GC-MS analysis of the oil has resulted in the identification of 23 components; piperitone, eucalyptol, camphor, chrysanthenone and borneol were the main components. Antimicrobial activity tests carried out with the fractions of the oil showed that the activity was mainly observed in those containing eucalyptol and camphor, in particular, followed by borneol and piperitone.     

Compositions and biological activities of essential oils of Kadsura longepedunculata and Schisandra sphenanthera

The chemical compositions, antimicrobial activities, antioxidant activities and cytotoxicities of the essential oils isolated from the root of Kadsura longepedunculata Finet et Gagnep (KLREO) and the fruit of Schisandra sphenanthera Rehd. et Wills. (SSFEO) were investigated.The analyses of gas chromatography-mass spectrometry (GC-MS) showed that cadinane type compounds and their derivatives were rich in both oils (54.2% and 39.7%, respectively) and delta-cadinene was the major component of both oils (13.8% and 25.6%, respectively). The antimicrobial activities of both oils were evaluated against five microorganisms with the disc diffusion and the broth micro-dilution method. Results showed that Gram-positive bacteria were more sensitive to both oils than Gram-negative bacteria and the yeast. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the oil of KLREO were lower than those of SSFEO, indicating that the former possessed slightly stronger antibacterial capability than the latter. The reducing power and lipid peroxidation assays were employed to study the potential antioxidant activities of both oils. Both oils remarkably decreased the content of malondialdehyde (MDA) in rat liver homogenate in a dose dependent manner. The antioxidant activities of KLREO appeared to be more potent than that of SSFEO. The oils of KLREO and SSFEO exhibited concentration-dependent cytotoxicities and were proved to be toxic to HepG2 cells with IC(50) of 147 and 189 mug/ml, respectively.     

The antimicrobial activity of the essential oil from Achillea fragrantissima

Essential oil from Achillea fragrantissima exerted a bactericidic effect on several gram positive and gram negative bacterial strains, as well as on Candida albicans. The oil was fractionated on sillica gel columns by a gradient of ether in petrol ether (30 degrees C-40 degrees C). Two fractions which contained less polar compounds were active against C. albicans only. The fractions which contained more polar compounds inhibited the growth of all the microorganisms tested. One of these compounds was identified as terpinen-4-ol. Commercial terpinen-4-ol had a similar antimicrobial activity.     

Phytochemical analysis and in vitro antimicrobial activity of two Satureja species essential oils

The phytochemical GC[sol ]MS analysis and in vitro antimicrobial activity of the essential oils of the aerial parts of Satureja montana L. and Satureja cuneifolia Ten., collected in Croatia were performed. The major compound of S. montana oil was the phenolic monoterpene carvacrol (45.7%). Other important compounds were the monoterpenic hydrocarbons p-cymene (12.6%), gamma-terpinene (8.1%) and the oxygen-containing compounds carvacrol methyl ether, borneol, thymol and thymol methyl ether. The volatile oil of S. cuneifolia was characterized as beta-cubebene (8.7%), limonene (8.3%), alpha-pinene (6.9%), spathulenol and beta-caryophyllene. The antimicrobial effects of S. montana and S. cuneifolia oils were found to have a broad spectrum activity against multidrug-resistant pathogens by the broth microdilution method. These oils were active against all the test strains, with the exception of Pseudomonas aeruginosa. Compared with S. cuneifolia, savory oil exhibited greater antimicrobial activity. The maximum activity of savory oil was observed against Escherichia coli, methicillin-resistant Staphylococcus aureus and against the yeast (Candida albicans). The essential oil of S. cuneifolia was also found to inhibit the growth of medically important pathogens such as S. aureus and E. coli. Fungicidal activity for both oils against C. albicans and S. cerevisiae was also observed.     

In vitro antimicrobial activity of extracts of four Achillea species: the composition of Achillea clavennae L. (Asteraceae) extract

The extracts of aerial parts of Achillea clavennae, Achillea holosericea, Achillea lingulata and Achillea millefolium (hexane:ether:methanol=1:1:1) have been tested for antimicrobial activity in a disk diffusion assay against five bacteria (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Salmonella enteritidis) and two fungi (Aspergillus niger and Candida albicans). Extracts of all four species possessed a broad spectrum of antimicrobial activity against all tested strains. The composition of the extract of Achillea clavennae, which showed the strongest activity, was investigated and the structures of isolated compounds were elucidated by spectral means (1D and 2D NMR, UV, IR and MS). The extract yielded alkanes, fatty acids, monoterpenes, guaiane sesquiterpenes (rupicolin A and B, 1-deoxy-1alpha-peroxy-rupicolin A and B), and flavonoids (apigenin and centaureidin). This study confirms the ethnopharmacological use of plants from this genus and places Achillea clavennae L. on the same level as the recognized Achillea millefolium.     

Composition and antimicrobial activity of Achillea clavennae L. essential oil

The volatile constituents of Achillea clavennae L. (Asteraceae), rare plant of Europe, have been analysed using GC/MS. Twenty- five components making up 81.6% of the oil were characterized with camphor (29.5%), myrcene (5.5%), 1,8-cineole (5.3%), beta-caryophyllene (5.1%) and linalool (4.9%) being the major constituents. The essential oil was evaluated for antibacterial and antifungal activities. The screening of the antimicrobial activity of essential oil was conducted by a disc diffusion test against Gram-positive (Bacillus subtilis, Bacillus cereus, Staphylococcus aureus, Streptococcus faecalis), Gram-negative (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis) and fungal organisms (Aspergillus niger, Aspergillus fumigatus, Candida albicans). The activity was more pronounced against Gram-negative and fungal organisms than against Gram-positive bacteria. A. clavennae oil was found to possess antimicrobial activity against Klebsiella pneumoniae, Pseudomonas aeruginosa and all fungal organisms.     

The essential oil of Senecio graveolens (Compositae): chemical composition and antimicrobial activity tests.

The chemical composition of the essential oil obtained from Senecio graveolens (Compositae) was analyzed by GLC-MS and the components identified were: isovaleraldehyde, alpha-pinene, alpha-phellandrene, alpha-terpinene, p-cymene, sabinene, gamma-terpinene, 1-methyl-4-isopropenylbenzene, terpinolene, terpinen-4-ol, piperitenone, alpha- and beta-eudesmol. The investigation by the agar-well diffusion method of the antimicrobial activity of the essential oil proved that it has antibacterial effects on Micrococcus luteus ATCC 9341, oxacillin-sensitive and oxacillin-resistant Staphylococcus aureus, as well as antifungal effects on clinically isolated Candida albicans. The minimal inhibitory concentration (MIC) values for M. luteus, oxacillin-sensitive S. aureus and C. albicans were 8.73, 10.91 and 2.13 x 10(-2) mg/ml, respectively. The antimicrobial activity related to known antibiotics was calculated. These results would be compatible with a potential concentration-dependent selectivity of antifungal effect of S. graveolens essential oil. Minimal bactericidal concentration (MBC) is above 87.3 mg/ml. Thus the MBC:MIC ratio would be clearly higher than 1 (above 8), indicating a bacteriostatic effect of the essential oil.     

In vitro antimicrobial efficacy of leaf essential oils of Chukrasia tabularis Adr Juss and Melia dubia Cav (Meliaceae)

The essential oils of Chukrasia tabularis and Melia dubia were tested for their antimicrobial activity against ten different pathogenic microorganisms responsible for human pathologies using standard antimicrobial assays. Chukrasia tabularis leaf oil exhibited strong antibiotic activities against Proteus vulgaris and Fusarium oxysporum and did not show any activity against the tested bacteria. Melia dubia leaf essential oil exhibited bacteriostatic and fungistatic activities against Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae and Fusarium oxysporum and Candida albicans respectively. The inhibitory activities of both essential oils are comparable with that of respective standards.     

Antibacterial and antioxidant activities in Sideritis italica (Miller) Greuter et Burdet essential oils

Sideritis italica (Miller) Greuter et Burdet is a widespread Lamiacea in the Mediterranean region used in traditional medicine. Essential oils were antibacterial against nine ATCC and as many clinically isolated Gram-positive and Gram-negative bacterial strains. Antibacterial activity was also found against Helicobacter pylori: a dose-dependant inhibition was shown between 5 and 25 microg/ml. The antibacterial activity of the oils was expressed as MICs (minimum inhibitory concentrations) and MBCs (minimum bactericidal concentrations). At a concentration between 3.9 and 250 microg/ml the oils showed a significant antibacterial effect against both Gram-negative and Gram-positive bacteria. In particular the ATCC strains Pseudomonas aeruginosa (MIC=3.9 microg/ml and 7.8 for flowerheads and leaves, respectively), Proteus mirabilis (MIC=15.6 and 7.8 microg/ml), Salmonella typhi (MIC=7.8 microg/ml) and Proteus vulgaris (MIC=15.6 microg/ml) were the most inhibited. Only Pseudomonas aeruginosa showed MBC at a concentration between 62.6 and 125 microg/ml. The antioxidant activity of the essential oils was evaluated by two cell free colorimetric methods: ABTS and DMPD; leaf oil is more active (4.29 +/- 0.02 trolox equivalents and 4.53 +/- 0.67 ascorbic acid equivalents by ABTS and DMPD, respectively). Finally the antioxidant activity of the essential oils was also evaluated by their effects on human whole blood leukocytes (WB) and on isolated polymorphonucleate (PMN) chemiluminescence. Comparing the effects of the oils from leaves and flowerheads on both PMN and WB chemiluminescence emission, we found no significant differences. Essential oils showed a dose-dependent and linear inhibitory activity on isolated PMN as well as on WB CL emission when PMA-stimulated. On the contrary, the inhibitory activity on resting cells was nonlinear. Our data represent an answer to the continual demand for new antibiotics and antioxidants for the continuous emergence of antibiotic-resistant strains and the growing interest in the substitution of synthetic antioxidants with natural ones. Furthermore, our finding of antibacterial and antioxidant activities in the essential oils from Sideritis italica flowerheads and leaves validated the use of the plant for medical purposes.     

Antioxidant and antimicrobial activity of the essential oil and methanol extracts of Achillea millefolium subsp. millefolium Afan. (Asteraceae)

The in vitro antimicrobial and antioxidant activities of the essential oil and methanol extracts of Achillea millefolium subsp. millefolium Afan. (Asteraceae) were investigated. GC-MS analysis of the essential oil resulted in the identification of 36 compounds constituting 90.8% of the total oil. Eucalyptol, camphor, alpha-terpineol, beta-pinene, and borneol were the principal components comprising 60.7% of the oil. The oil strongly reduced the diphenylpicrylhydrazyl radical (IC(50)=1.56 micro g/ml) and exhibited hydroxyl radical scavenging effect in the Fe(3+)-EDTA-H(2)O(2) deoxyribose system (IC(50)=2.7 micro g/ml). It also inhibited the nonenzymatic lipid peroxidation of rat liver homogenate (IC(50)=13.5 micro g/ml). The polar phase of the extract showed antioxidant activity. The oil showed antimicrobial activity against Streptococcus pneumoniae, Clostridium perfringens, Candida albicans, Mycobacterium smegmatis, Acinetobacter lwoffii and Candida krusei while water-insoluble parts of the methanolic extracts exhibited slight or no activity. This study confirms that the essential oil of Achillea millefolium possesses antioxidant and antimicrobial properties in vitro.     

The composition, geographical variation and antimicrobial activity of Lippia javanica (Verbenaceae) leaf essential oils

Lippia javanica is widely distributed throughout South Africa where it is used extensively in traditional herbal preparations. An infusion of the leaves is commonly used as a decongestant for colds and coughs. A preliminary study indicated that the essential oil chemistry varies dramatically both within and between natural plant populations. As the antimicrobial activity may be directly related to the specific composition of the oil, the activity may also fluctuate. The aerial parts of Lippia javanica were collected from various localities in southern Africa to study the essential oil composition and the antimicrobial activity thereof. The hydrodistilled essential oils were analysed by GC/MS and a cluster analysis was performed on the essential oil dataset. From 16 samples (representing five natural populations), 5 chemotypes were identified; a myrcenone rich-type (36-62%), a carvone rich-type (61-73%), a piperitenone rich-type (32-48%), an ipsenone rich-type (42-61%) and a linalool rich-type (>65%). The myrcenone and linalool chemotypes have been mentioned in the literature but the carvone, ipsenone and piperitenone chemotypes have not previously been reported for Lippia javanica. Time kill studies were performed on three microbial respiratory isolates to document the scientific rationale of using Lippia to treat respiratory complaints in traditional herbal medicine. Klebsiella pneumoniae, Cryptococcus neoformans and Bacillus cereus showed reduction in microbial populations with the strongest bacteriostatic effect observed for Klebsiella pneumoniae.     

Chemical composition and antimicrobial activity of the essential oils of Chrysanthemum indicum

Three essential oils from three samples: fresh, air-dried and processed flowers of Chrysanthemum indicum, obtained by hydrodistillation, were analyzed by GC-MS. The results show that major constituents of the three oils were 1,8-cineole, camphor, borneol and bornyl acetate, but the percentage of these compounds varied greatly because of the processing of flowers. The antimicrobial activity of essential oils from air-dried and processed flowers was evaluated against 15 microorganisms including three yeasts and seven clinical isolated strains using disc paper and broth microdilution methods. Our results show that both essential oils possessed significant antimicrobial effect, however, some difference in antimicrobial activity between two oils was observed for several microorganisms, which was attributed to the variation in percentage of the components. With higher percentage of camphor, the oil of the processed flowers exhibited, in many cases, greater bacteriostatic activity than that of the air-dried ones.     

Antigenotoxic and antioxidant activities of palmarosa and citronella essential oils

Ethnopharmacological relevance

Essential oils of palmarosa and citronella have been extensively used in ancient Indian and South-east Asian traditional medicines.

Aim of the study

These essential oils have been reported to exhibit antimicrobial, anti parasitic effects against bacteria, yeasts, filamentous fungi, and viruses. In the present study the oils were tested for their potential antigenotoxic and antioxidant properties in human lymphocyte cells.

Materials and methods

The antigenotoxic effect on human lymphocyte cells (measurement of cell viability, DNA damage) was studied using trypan blue dye exclusion test, plasmid pBR322 DNA strand scission, and comet assay. Anti-oxidant activity was evaluated by DPPH⁺ free radical scavenging and lipid peroxidation assay.

Results

The essential oils showed a good antigenotoxic activity against methyl methanesulphonate (MMS) and hydrogen peroxide. In addition, a significant dose dependent antioxidant activity was observed.

Conclusion

Our data provide evidence that support the usage of palmarosa and citronella essential oils in traditional herbal preparations. They can constitute a natural source of a new and safe antioxidant.     

Chemical composition and antimicrobial activity of the essential oils from two species of Eucalyptus

The leaf-essential oil from Eucalyptus robusta and E. saligna, the latter in two phenologic stages, were analysed by gas chromatography coupled to mass spectrometry (GC-MS). The major constituent in E. robusta oil was the monoterpene alpha-pinene (73.0% of the total amount). The oil composition of the E. saligna was dependent of the phenologic stage. In the vegetative phase, the major constituents were p-cymene (54.2%) and gamma-terpinene (43.8%), while during the blossoming alpha-pinene became the major constituent followed by p-cymene (22.5%). Additionally, the antimicrobial activity for all three oils was evaluated against Staphylococcus aureus, Escherichia coli and Candida albicans. The E. robusta oil presented the highest growth inhibition for all the microorganisms tested.     

Chemical compositions and anti-influenza activities of essential oils from Mosla dianthera

Ethnopharmacological relevance

Mosla dianthera as an aromatic herb is used in folk medicine for the treatment of cough, colds, fever, bronchitis, nasal congestion and headache.

Aim of the study

To characterize chemical compositions and to evaluate the anti-influenza effects of essential oils of M. dianthera (MDEO) in influenza virus A (IVA) infected mice.

Materials and methods

MDEO was obtained by hydrodistillation and analysed by gas chromatography-mass spectrometry (GC-MS). ICR mice were treated with MDEO for 5 consecutive days at doses of 90-360 mg/kg after post-infected. Levels of Serum IL-4 and IFN-γ were assayed by ELISA. Levels of MOD, SOD, TAOC and GSH-Px in lung tissue were determined by colorimetric method.

Results

GC-MS analysis revealed the presence of 29 components that account for 97.74% of phenolic sesquiterpenes and aromatic compounds. The major compounds were elemicin (16.51%), thymol (14.77%), β-caryophyllene (14.49%), iso-elemicin (9.22%), asarone (6.09%) and α-caryophyllene (5.26%). It had significant effects on decreasing lung viral titers, inhibiting pneumonia, reducing levels of serum IFN-γ and IL-4, and enhancing antioxidant activity in the lung tissue of IVA infected mice.

Conclusions

MPE could exhibit therapeutical effects in IVA infected mice as a suppressor of IVA replication and inflammatory mediators and a promoter of antioxidant potentials. Therefore, MDEO could provide a safe and effective therapeutic candidate for treatment of influenza and its subsequent viral pneumonia.     

Chemical composition,antimicrobial, insecticidal,phytotoxic and antioxidant activities of Mediterranean Pinus brutia and Pinus pinea resin essential oils

Essential oils of the resins of Pinus brutia and Pinus pinea were evaluated for their biological potential. Essential oils were characterized using GC-MS and GC/FID. In vitro antimicrobial, phytotoxic, antioxidant, and insecticidal activities were carried out using the direct contact and the fumigant assays, respectively. The chemical profile of the essential oils of the resins ofP pinea and P brutia included mainly a-pinene （21.39% and 25.40%）, β-pinene （9.68% and 9.69%）, and caryophyllene （9.12% and 4.81%）. The essential oils of P pinea and P brutia exerted notable antimicrobial activities on Micrococcus luteus and Bacillus subtilis, insecticidal activities on Ephestia kuehniella eggs, phytotoxic activities on Lactuca sativa, Lepidium sativum, and Portulaca oleracea, as well as antioxidant potential. Indications of the biological activities of the essential oils suggest their use in the formulation of ecofriendly and biocompatible pharmaceuticals.     

Anticancer and antiviral activities of Youngia japonica (L.) DC (Asteraceae, Compositae)

Aqueous and ethanol extracts of Youngia japonica (also known as Oriental hawksbeard) were tested in vitro for anti-tumor activity against three cell lines, human promyelocytic leukaemia (HL-60), human myelogenous leukaemia (chronic K-562) and mouse Sarcoma 180 (S-180), and for antiviral activity against respiratory syncytial virus (RSV), influenza A virus (Flu A) and herpes simplex virus type 1 (HSV-1) by cytopathic effect (CPE) reduction assay. Hot water extract of Youngia japonica inhibited cell proliferation and growth of all cancer cell lines to various extent. K-562 cells were the most sensitive to the extract whereas S-180 cells were the least. It did not show any significant cytotoxic effects on normal mammalian Vero cells up to the concentration of 450 microg/mL. The ethanol extract of whole plant of Youngia japonica exhibited antiviral activity against RSV cultured in HEp-2 cells, but did not have any activity against Flu A and HSV-1. Two partially purified fractions (Fr.10 and Fr.11) from the 95% ethanol extract exhibited significant anti-RSV with 50% inhibitory concentration (IC50) in the range of 3.0-6.0 microg/mL. The ratio of the viral titer reduction in the absence (viral control) and presence of the maximal non-cytotoxic concentration (MNCC) of the Fr.10 and Fr.11 was both estimated to be 1 x 10(4) (RF, viral titer reduction factors), indicating that their anti-RSV activity was high enough to justify for further analysis. Our preliminary analysis showed that the antiviral ingredients were likely to contain phenolic compounds including tannins by chemical tests.     

The chemical composition of some Lauraceae essential oils and their antifungal activities

The antifungal activity of Aniba rosaeodora, Laurus nobilis, Sassafras albidum and Cinnamomum zeylanicum essential oils were investigated against 17 micromycetes. Among the tested fungal species were food poisoning, spoilage fungi, plant and animal pathogens. In order to determine fungistatic and fungicidal concentrations (MIC and MFC) macrodilution and microdilution tests were used. Linalool was the main component in the essential oil of A. rosaeodora, while 1.8-cineole was dominant in L. nobilis. In sassafras essential oil safrole was the major component and in the oil of C. zeylanicum the main component was trans-cinnamaldehyde. The essential oil of cinnamon showed the strongest antifungal activity.     

Butyryl- and acetyl-cholinesterase inhibitory activities in essential oils of Salvia species and their constituents

Extracts of Salvia (sage) species have been reported to have cholinergic activities relevant to the treatment of Alzheimer's disease. A lack of information on the inhibition of the enzyme butyrylcholinesterase, also considered to be a target in the treatment of the disease, prompted this in vitro investigation of the essential oils of S. fruticosa, S. lavandulaefolia, S. of ficinalis and S. of ficinalis var. purpurea for anti-butyrylcholinesterase activity. Dose-dependent inhibition of human cholinesterases by the extracts and constituents was determined using the method of Ellman. A time dependent increase in the inhibition of butyrylcholinesterase by the oils of S. fruticosa and S. of ficinalis var. purpurea was evident. IC(50) values decreased from 0.15 +/- 0.007 and 0.14 +/- 0.007 mg/mL after 5 min to 0.035 +/- 0.016 and 0.06 +/- 0.018 mg/mL after 90 min incubation time respectively. The slow onset of inhibition of butyrylcholinesterase was also shown by individual constituents, such as 3-carene and beta-pinene. Analyses of the chemical composition of the oils and anti-butyrylcholinesterase activity of their constituents revealed that none of the compounds tested would account for the total activity of the oils and that synergy is likely.     

Chemical composition and antimicrobial activity of the essential oils of different samples of Thymus baeticus boiss

Gas chromatography was used to determine the chemical composition of the essential oil of female and hermaphrodite Thymus baeticus Boiss. collected in Ugijar (province of Granada, Spain). The results were compared with the chemical composition of other samples of the same species, collected in Lanjarón. These comparisons showed some qualitative differences, and more obvious quantitative differences, in the compositions of the essential oils. We also investigated the antimicrobial activity of all samples. This activity, although marked in all samples, was greater in essential oils containing larger amounts of geraniol.