Abstract
The chemical composition of the essential oils from the leaves and fruit of Eucalyptus camaldulensis grown in Mersin, Turkey was analyzed using gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques. The biological activities (antibacterial and antifungal) were examined using the agar well diffusion method. The main leaf oil constituents were p-cymene (42.1%), eucalyptol (1,8-cineole) (14.1%), α-pinene (12.7%) and α-terpinol (10.7%). The main constituents of the fruit oil were eucalyptol (1,8-cineole) (34.5%), p-cymene (30.0%), α-terpinol (15.1%) and α-pinene (9.0%). Our results showed that both types of oils are rich in terms of monoterpene hydrocarbons and oxygenated monoterpenes. The leaf and fruit essential oils of E. camaldulensis significantly inhibited the growth of Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Streptococcus sp.) bacteria (p<0.05). The oils also showed fungicidal activity against Candida tropicalis and C. globrata. Leaf essential oils showed more activity than fruit essential oils, probably due to the higher p-cymene concentration in leaves.
1 Introduction
Eucalyptus is one of the world’s important and most widely planted genera belonging to the family Myrtaceae. This family includes 140 genera and about 3800 species grown in tropical and subtropical parts of the world [1], [2]. The Myrtaceae family represents an important source of essential oils with diverse biological activities including bacteriostatic, fungistatic and anti-inflammatory effects. Various Myrtaceae species possess strong antimicrobial potential and their volatile oils are used as antimicrobial and antifungal agents in creams, soaps and toothpastes [3], [4].
Eucalyptus is native to Australia, and the genus contains about 600 species [5]. A smaller number are also native to New Guinea, Indonesia and the Phillipines [6]. Eucalyptus is a fast-growing tree, and is suitable for use in paper production. There has been extensive overseas forest plantation of Eucalyptus trees. Leaves are a by-product of tree cutting, and the use of the excess leaves for biomass resources is considered to be an important research subject [5]. Eucalyptus is a monotypic genus in the flora of Turkey. Mainly an Australian genus, in Turkey Eucalyptus camaldulensis is grown commercially for timber and is naturalized, while several other species, including E. robustus Sm., E. globolus Lab., E. tereticornis Sm., are occasionally planted, mainly for ornamental reasons. Eucalyptus camaldulensis is a large evergreen tree that grows up to 15 m in Turkey where it is commercially grown, especially around Mersin and Adana. It is also extensively naturalized and invasive on roadsides, sand dunes, etc. [7].
Several species of Eucalyptus are used in folk medicine as an antiseptic and against infections of the upper respiratory tract, such as colds, influenza and sinus congestion. The antimicrobial, analgesic and anti-inflammatory properties of E. citriodora, E. globulus, E. teretcorni and E. camaldulensis have been reported from different parts of the world [8]. The essential oil of the Eucalyptus species shows a wide spectrum of antimicrobial [9], [10], antifungal [11], [12], anticandidal [13], antibacterial [14], [15], expectorant and cough stimulant activity [16]. Due to its disinfectant action, the essential oil is used externally and applied to cuts and skin infections but it has a deleterious effect on the body in high doses [17], [18]. Besides its antimicrobial uses, the essential oils and their constituents have also been used for their herbicidal [19], [20], insecticidal [21], [22], antihelmintic [23], anti-tumor [24] and anti-leeching [25] properties, as well as in integrated nonspecific disease skin infections [26] and mastitis [27], [28]. Rahimi-Nasrabadi et al. [29], [30], [31] have studied the chemical composition, antioxidant and antimicrobial activities of different Eucalyptus sp. essential oils and methanol extracts.
Eucalyptus extracts are often used in oral hygiene products (mouth rinses, toothpastes, anti-plaque chewing gums) and surface cleaning wipes etc. Many screening reports, using disc diffusion and dilution techniques, have established the antimicrobial activity of Eucalyptus extracts from various species against a number of pathogens including Haemophilus influenzae, Streptococcus pneumoniae, Staphylococcus aureus, Escherichia coli, Aspergillus niger, Porphyromonas gingivalis, Streptococcus sobrinus, Streptococcus mutans, Salmonella typhimurium, Pseudomonas aeruginosa and Staphylococcus epidermidis [32], [33], [34], [35], [36], [37].
In this study, we aimed to identify the chemical composition of the leaf and fruit essential oils of E. camaldulensis, to show their antimicrobial activities on some bacteria and fungi and also to compare them with the Eucalyptus genus patterns.
2 Experimental
2.1 Plant material
The leaves and fruit of E. camaldulensis were collected from natural habitats in Mersin, in July 2015. The leaves and fruit were dried in the shade at room temperature. The voucher specimen for E. camaldulensis (Dogan 2439) has been deposited in the Fırat University Herbarium (FUH).
2.2 Extraction of essential oil
The essential oil was extracted by hydrodistillation using a modified Clevenger apparatus coupled to a 2 L round-bottom flask. A total of 100 g of fresh plant material (aerial parts) and 1 L of water were used for the extraction. The chemical analyses were performed in the Plant Products and Biotechnology Research Lab at Firat University. The extraction was performed over a 3-h period. The oil was transferred to black-colored vials, wrapped in parafilm and aluminum foil and stored at 4 °C until analysis. The yields of the oils were calculated on the basis of the dry mass.
2.3 Gas chromatography (GC) analysis
The essential oil was analyzed using a HP 6890 GC equipped with a flame ionization detector (FID) and a HP-5ms (30 m×0.25 mm i.d., film thickness 0.25 μm) capillary column was used. The column and analysis conditions were the same as in GC-MS, as expressed below. The percentage composition of the essential oils was computed from GC-FID peak areas without correction factors.
2.4 Gas chromatography/mass spectrometry (GC-MS) analysis
GC-MS analyses of the oils were performed on a Hewlett Packard Gas Chromatography HP 6890 interfaced with a Hewlett Packard 5973 mass spectrometer system equipped with a HP-5ms capillary column (30 m×0.25 mm i.d., film thickness 0.25 μm) (J&X Scientific). The oven temperature was programed from 70 to 240 °C at the rate of 5 C/min. The ion source was set at 240 °C and the electron ionization at 70 eV. Helium was used as the carrier gas at a flow rate of 1 mL/min. The scanning range was 35–425 amu. Diluted oil in n-hexane (1.0 μL) (Merck) was injected into the GC-MS. The identification of constituents was performed on the basis of the retention index (RI) determined by co-injection with reference to a homologous series of n-alkanes (C8–C25) [38] under identical experimental conditions [39]. Further identification was performed by comparison of their mass spectra with those from NIST 98 Libraries (on ChemStation HP) and Wiley 7th Version. The relative amounts of individual components were calculated based on the GC (HP-5ms column) peak area (FID response) without using correction factors. The identified constituents of the essential oils are listed in Table 1.
Phytochemical composition of leaf and fruit essential oils from E. camaldulensis.
| Name of Compound | RI | Leaf (%) | Fruit (%) |
|---|---|---|---|
| α-pinene | 1020 | 12.7 | 9.0 |
| p-cymene | 1090 | 42.1 | 30.0 |
| Limonene | 1094 | 5.5 | – |
| Eucalyptol (1,8-cineole) | 1096 | 14.1 | 34.5 |
| γ-terpinene | 1115 | – | 5.1 |
| Borneol L | 1198 | 5.5 | 5.3 |
| α-terpineol | 1214 | 10.7 | 15.1 |
| Spathulenol | 1493 | 3.2 | – |
| Monoterpene hydrocarbons | 60.3 | 44.1 | |
| Oxygenated monoterpenes | 30.3 | 54.9 | |
| Oxygenated sesquiterpenes | 3.2 | – | |
| Total identified | 93.8 | 99.0 |
RI, Retention index relative to C8–C25 n-alkanes on HP-5 column.
2.5 Antimicrobial activity
2.5.1 Microbial strains and culture media
All media were supplied by LAB Ltd (UK). All microbial strains were obtained from the Microbiology Laboratory, Department of Biology, Science Faculty of Firat University. Stock cultures of Gram-positive S. aureus (ATCC 6538P) and Bacillus subtilis (ATCC 6633), Gram-negative E. coli (ATTC 25922), Streptococcus sp. (ATCC 8059) and the yeasts Candida tropicalis (ATCC 13803) and C. globrata (ATCC 66032) were subcultured and maintained in nutrient broth at 37 °C for 24 h. Briefly, 100 μL of test bacteria/fungi were grown in 10 mL of fresh media until they reached a count of approximately 108 cells/mL for bacteria or 105 cells/mL for fungi. Then, 100 μL of microbial suspension was spread onto agar plates corresponding to the broth in which they were maintained.
2.5.2 Antimicrobial screening
The agar well diffusion method was employed for the determination of the antimicrobial activities of the essential oils and standard antibiotics [40]. The results of the essential oils were discussed with standard antibiotics as the positive controls [amikacin (30 μg) AK30, gentamicin (10 μg) CN10, tetracycline (30 μg) TE30 and netilmycin (30 μg) NET30]. All tests were performed in triplicate.
2.5.3 Agar well diffusion method
A suspension of the test microorganism, 0.1 mL of 108 cells/mL, was spread on the Muller Hinton Agar (MHA). The wells (6 mm diameter) were cut from the agar and different concentrations (10, 20 and 30 μL) of essential oils were delivered into them. After incubation for 24 h at 37 °C, all plates were examined for each zones of growth inhibition, and the diameters of these zones were measured in millimeters.
3 Results and discussion
3.1 Chemical composition of essential oil
This study evaluated the chemical composition and antimicrobial activities of the essential oil from the leaves and fruit of E. camaldulensis in Mersin, Turkey. The yields of the leaf essential oils were 1.2% and 1.0% (v/w) in fruit essential oils. A total of seven and six compounds were identified representing 93.8% and 99.0% of the total oils, respectively. The major constituents of the leaves were p-cymene (42.1%), eucalyptol (1,8-cineole) (14.1%), α-pinene (12.7%) and α-terpinol (10.7%), and in the fruit were eucalyptol (1,8 cineole) (34.5%), p-cymene (30.0%), α-terpinol (15.1%) and α-pinene (9.0%). The results of the GC-MS analysis of the oils are presented in Table 1.
It was previously reported that the main constituents of oil in E. camaldulensis were 1,8-cineole (21.75%), β-pinene (20.51%), α-pinene (15.6%) and terpineol (9.41%); spathulenol (37.46%), p-cymene (17.20%) and crypton (8.88%) in E. gomphocephala; spathulenol (18.37%), p-cymene (19.38%) and crypton (16.91%) in E. camaldulensis var. obtusa [41].
In the study by Elaissi et al., the main components in the essential oil of 15 Eucalyptus species were reported to be 1,8-cineole, followed by spathulenol [42]. Traore et al. also found 1,8-cineole, p-cymene, α-pinene, limonene, γ-terpinene and trans-pinocarveol to be the main compounds in the essential oils of E. camaldulensis from Mali [43]. The chemical composition of the hydrodistilled essential oils of leaves from three species of Eucalyptus, E. spathulata, E. microtheca and E. torquata, was analyzed and the predominant and common components were 1,8-cineole, α-pinene, terpine-4-ol, α-terpineol, aromadendrene and viridiflorol [44]. In the Rahimi-Nasrabadi et al. [30] study, the chemical composition of the essential oil from the leaves of E. procera cultivated in central Iran was analyzed. Forty-five constituents representing 99.6% of the oil were identified. The main constituents of the oil were found to be 1,8-cineole (35.9%), α-pinene (25.6%) and viridiflorol (7.7%). In a similar study, on the essential oil from the aerial parts of E. loxophleba, 39 compounds were identified representing around 98.0% of the total oil. The major constituents of the oil were found to be 1,8-cineole (39.4%), methyl amyl acetate (19.8%), aromadendrene (10.0%), viridiflorol (6.0%) and α-pinene (5.4%) [31]. It is possible to say that our results have shown congruency with the other Eucalyptus essential oil studies especially on major compounds.
3.2 Antibacterial and antifungal activities of essential oils
The antibacterial and antifungal activity results are summarized in Tables 2 and 3. The results indicate that the inhibition zones (IZs) resulting from the antibacterial activities ranged between 9 and 25 mm at 10, 20 and 30 μg/mL oil concentrations (p<0.05). Both essential oils showed antibacterial activity against the studied bacterial strains. The inhibition zones resulting from the antifungal activities ranged between 12 and 23 mm at 10, 20 and 30 μg/mL oil concentrations (p<0.05).
Antibacterial activity of E. camaldulensis leaf and fruit essential oils against Gram-positive and Gram-negative bacterial strains.
| Bacterial strains | Essential oils | Antibiotic | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Leaf oil (μg/mL) | Fruit oil (μg/mL) | |||||||||
| 10 | 20 | 30 | 10 | 20 | 30 | NET | AK | CN | TE | |
| S. aureus IZ (mm) | 14±1.9 | 15±1.5 | 17±1.0 | 15±1.5 | 18±1.7 | 21±2.1 | 18±0.0 | 22±0.0 | 20±0.0 | 15±0.0 |
| B. subtilis IZ (mm) | 18±1.4 | 20±1.2 | 21±1.8 | 11±1.3 | 12±1.6 | 14±1.2 | 20±0.0 | 19±0.0 | 19±0.0 | 16±0.0 |
| E. coli IZ (mm) | 22±1.7 | 23±2.2 | 25±1.9 | 9±2.5 | 11±1.8 | 12±1.9 | 17±0.0 | 15±0.0 | 16±0.0 | 18±0.0 |
| Streptoccus sp. IZ (mm) | 18±1.3 | 19±1.8 | 22±2.5 | 10±1.2 | 18±1.6 | 18±1.1 | 16±0.0 | 17±0.0 | 15±0.0 | 19±0.0 |
IZ, Diameter of inhibition zone (mean±SD) (p<0.05); NET, netilmycin; AK, amikasin; CN, gentamycin; TE, tetracyclin.
Antifungal activity of E. camaldulensis leaf and fruit essential oils against fungal strains.
| Fungal strains | Essential oils | Antibiotic | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Leaf oil (μg/mL) | Fruit oil (μg/mL) | |||||||||
| 10 | 20 | 30 | 10 | 20 | 30 | NET | AK | CN | TE | |
| C. tropicalis IZ (mm) | 18±1.6 | 20±1.7 | 22±1.1 | 12±1.7 | 15±2.1 | 18±1.5 | NA | NA | NA | NA |
| C. globrata IZ (mm) | 19±1.5 | 20±1.0 | 23±1.7 | 13±1.9 | 18±1.6 | 20±1.3 | NA | NA | NA | NA |
IZ, Diameter of inhibition zone (mean±SD) (p<0.05); NA, not analyzed.
Eucalyptus camaldulensis essential oil significantly inhibited the growth of Gram-positive (S. aureus and B. subtilis) and Gram-negative (E. coli and Streptococcus sp.) bacteria strains. Fruit essential oil showed strong antibacterial activity against the S. aureus (21±2.1), Streptococcus sp. (18±1.1), B. subtilis (14±1.2) and E. coli (12±1.9), respectively (p<0.05) (Table 2). The fruit oil showed very effective fungicidal activity against C. tropicalis (18±1.5) and C. globrata (20±1.3) fungi (p<0.05). The leaf essential oil showed strong antibacterial activity against E. coli (25±1.9), B. subtilis (21±1.8), Streptococcus sp. (22±2.5) and S. aureus (17±1.05), respectively (p<0.05). The leaf oil showed efficacious antifungal activity against the C. tropicalis (22±1.1) and C. globrata (23±1.7) (p<0.05). These essential oils contain major compounds 1,8-cineole and p-cymene excessively which are suggested to show very rich antimicrobial activities against many significant pathogens.
Nikbakht et al. [44] tested the antifungal activities of essential oils of five Eucalyptus species (E. largiflorens, E. microtheca, E. oleosa, E. spathulata and E. torquata) using the minimum inhibitory concentration and disc diffusion methods against Aspergillus flavus, A. parasiticus, A. niger, Penicillium chryzogenum and P. citrinum. A high antifungal activity was found in the leaf oil of E. largiflorens. They also reported the chemical composition, antioxidant and antimicrobial activities of essential oils and methanolic extracts of E. largiflorens and E. oleosa from Iran. The major constituents of the oil of E. largiflorens were 1,8-cineole, cryptone, terpinen-4-ol, 4-allyloxyimino-2-carene, α-pinene, α-terpinyl acetate, cuminic aldehyde and p-cymen-7-ol. The essential oil showed strong antibacterial activity against E. coli, Salmonella typhimurium, Klebsiella pneumoniae, S. aureus, S. epidermidis, Bacillus cereus and B. subtilis. Also, the main components of essential oil of E. oleosa were 1,8-cineole, α-pinene, α-terpineol and trans-pinocarveol. The essential oil showed strong antibacterial activity against the above mentioned microorganisms [44].
In the study of the antibacterial, antifungal and anticancer activities of volatile oils and methanolic extracts of the stems, leaves and flowers of E. sideroxylon and E. torquata species, it was found that the flower oil of E. torquata exhibited potent antifungal activity against C. albicans and showed a moderate antifungal activity against C. albicans, A. flavus, and A. niger [45].
Salem et al. showed that the antibacterial activities of the essential oils of three Eucalyptus species, E. camaldulensis, E. camaldulensis var. obtusa and E. gomphocephala, resulted in IZs between 10 and 18 mm at 2000 μL/mL oil concentration. All essential oils demonstrated good antibacterial activity against the studied bacterial strains [41].
The antimicrobial activity of E. citriodora essential oil against pathogenic fungi, bacteria and drug-resistant mutants of C. albicans, E. coli and Mycobacterium smegmatis was evaluated following agar disc diffusion and broth dilution assay methods. Its effectiveness against Trichophyton rubrum followed by Histoplasma capsulatum, C. albicans and Cryptococcus neoformans was also assessed. It is reported that it is more active against Gram-positive than it is against Gram-negative bacteria and also showed more activity on drug-resistant mutants of C. albicans and E. coli [8]. Ghalem and Mohamed [46], demonstrated that leaf essential oils of E. globolus and E. camaldulensis exhibited inhibitory effects on S. aureus more than E. coli. Some correlation betweeen the amount of 1,8-cineole, p-cymene, α-pinene, of cryptone and the antibacterial activity were observed [47].
3.3 The relationship between antimicrobial activity and oil constituent
It is well demonstrated that the antimicrobial activity of an essential oil is linked to its chemical composition. The functional groups of compounds found in essential oils are associated with their antimicrobial characteristics [48]. It was reported that the antibacterial activity of Eucalyptus essential oils is generally due to components such as 1,8-cineole (eucalyptol), citronellal, citronellol, citronellyl acetate, p-cymene, eucamalol, limonene, linalool, β-pinene, γ-terpinene, α-terpineol, alloocimene and aromadendrene. For example several reports have shown that 1,8-cineole has strong antimicrobial activity against many important pathogens and spoilage organisms, including S. aureus and Fusarium solani [49]; E. coli and B. subtilis [50].
As a result of these findings, the antimicrobial activities of E. camaldulensis leaf and fruit oils could be attributed to eucalyptol (1,8-cineole), p-cymene, α-terpineol and α-pinene. The antimicrobial activities of these components have also been reported [32], [47], [51], [52], [53].
4 Conclusion
Our results showed that both oils are rich in terms of monoterpene hydrocarbons and oxygenated monoterpenes. This study demonstrates the occurrence of p-cymene/eucalyptol (1,8-cineole) and α-terpineol chemotype of E. camaldulensis in Turkey. This study clearly indicated that essential oils from both fruits and leaves of E. camaldulensis have antibacterial and antifungal effects on some pathogen microorganisms. These essential oils showed antimicrobial activity on both bacteria and fungi similar to the antibiotics used as positive controls. In some conditions the essential oils were determined to be more effective than the antibiotics. The major components of the essential oils, eucalyptol and p-cymene, could be responsible for these effects. Consequently, leaf essential oil appeared to be more effective than the fruit essential oil and this effect might be because of its rich p-cymene content.
References
1. Akin M, Aktumsek A, Nostro A. Antibacterial activity and composition of the essential oils of Eucalyptus camaldulensis Dehn and Myrtus communis L. growing in Northern Cyprus. Afr J Biotechnol 2010;9:531–5.Search in Google Scholar
2. Ali N, Ahmed G, Ali S, Shah I, Ghias M, Khan I. Acute toxicity, brine shrimp cytotoxicity and relaxant activity of fruits of Callistemon citrinus Curtis. BMC Complement Altern Med 2011;11:99.10.1186/1472-6882-11-99Search in Google Scholar
3. Mabberley DJ. The plant-book. Cambridge: Cambridge University Press, 1997.Search in Google Scholar
4. Lis-Balchin M, Hart SL, Deans SG. Pharmacological and antimicrobial studies on different tea-tree oils (Melaleuca alternifolia, Leptospermum scoparium or Manuka and Kunzea ericoides or Kanuka), originating in Australia and New Zealand. Phytother Res 2000;14:623–9.10.1002/1099-1573(200012)14:8<623::AID-PTR763>3.0.CO;2-ZSearch in Google Scholar
5. Takahashi T, Kokubo R, Sakaino M. Antimicrobial activities of Eucalyptus leaf extracts and flavonoids from Eucalyptus maculate. Lett Appl Microbiol 2004;39:60–4.10.1111/j.1472-765X.2004.01538.xSearch in Google Scholar
6. Cock IE. Antibacterial activity of selected Australian native plant extracts. Internet J Microbiol 2008;4:2.Search in Google Scholar
7. Davis PH. Flora of Turkey and the East Aegean Islands. Edinburgh: Edinburgh University Press, Vol. 4, 1972.Search in Google Scholar
8. Luqman S, Dwivedi GR, Darokar MP, Kalra, A, Khanuja SP. Antimicrobial activity of Eucalyptus citriodora essential oil. Inter J Essent Oil Therapeutics 2008;2:69–75.Search in Google Scholar
9. Hajji F, Tetouani SF, Tantaui EA. Antimicrobial activity of twentyone Eucalyptus essential oils. Fitoterapia 1993;64:71–7.Search in Google Scholar
10. Changriha N, Cherif YF, Baailouamer A, Meklati BY. Antimicrobial of Algerian Cyprus and Eucalyptus essential oils. Rivista Italiana EPPOS 1998;5:11–6.Search in Google Scholar
11. Ramezani H. Fungicidal activity of volatile oil from Eucalyptus citriodora Hook against Alternaria triticana. Common Agric Appl Bio Sci 2006;71:909–14.Search in Google Scholar
12. Ramsewak RS, Nair MG, Stommel M, Selanders L. In vitro antagonistic activity of monoterpenes and their mixtures against toe nail fungus pathogens. Phytother Res 2003;17:376–9.10.1002/ptr.1164Search in Google Scholar
13. Dutta BK, Karmakar S, Naglot A, Aich JC, Begam M. Anticandidial activity of some essential oils of a mega biodiversity hotspot in India. Mycoses 2007;50:121–4.10.1111/j.1439-0507.2006.01332.xSearch in Google Scholar
14. Cimanga K, Kambu K, Tona L, Apers S, De Bruyne T, Hermans N, et al. Correlation between chemical composition and antibacterial activity of essential oils of some aromatic medicinal plants growing in the Democratic Republic of Congo. J Ethnopharmacol 2002;79:213–20.10.1016/S0378-8741(01)00384-1Search in Google Scholar
15. Low D, Rawal BD, Griffin WJ. Antibacterial action of the essential oils of some Australian Myrtaceae with special references to the activity of chromatographic fractions of oil of Eucalyptus citriodora. Planta Med 1974;26:184–9.10.1055/s-0028-1097987Search in Google Scholar
16. Oyedeji AO, Ekundayo O, Olawore ON, Adeniyi BA, Koenig WA. Antimicrobial activity of the essential oils of five Eucalyptus species growing in Nigeria. Fitoterapia 1999;70:526–8.10.1016/S0367-326X(99)00083-0Search in Google Scholar
17. Tibballs J. Clinical effects and management of Eucalyptus oil. Ingestion in infants and young children. Med J Aust 1995;163:177–80.10.5694/j.1326-5377.1995.tb124516.xSearch in Google Scholar
18. Whitman BW, Ghazizadeh H. Eucalyptus oil (from Eucalyptus spp. including Eucalyptus globulus) therapeutic and toxic aspects of pharmacology in human and animals. J Paediatr Child Health 1994;30:190–1.10.1111/j.1440-1754.1994.tb00613.xSearch in Google Scholar
19. Setia N, Batish DR, Singh HP, Kohli RK. Phytotoxicity of volatile oil from Eucalyptus citriodora against some weedy species. J Environ Biol 2007;28:63–6.Search in Google Scholar
20. Batish DR, Singh HP, Setia N, Kaur S, Kohli RK. Chemical composition and phytotoxicity of volatile essential oil from intact and fallen leaves of Eucalyptus citriodora. Z Naturforsch 2006;61:465–71.10.1515/znc-2006-7-801Search in Google Scholar
21. Rudin W. Protection against insects. Ther Umsch 2005;62:713–8.10.1024/0040-5930.62.11.713Search in Google Scholar
22. Park IK, Shin SC. Fumigant activity of plant essential oils and components from garlic (Allium sativum) and clove bud (Eugenia caryophyllata) oils against the Japanese termite (Reticulitemes speratus Kolbe). J Agric Food Chem 2005;153:4388–92.10.1021/jf050393rSearch in Google Scholar
23. Bennet-Jenkins E, Bryant C. Novel sources of anthelmintics. Int J Parasitol 1996;26:937–47.10.1016/S0020-7519(96)80068-3Search in Google Scholar
24. Takasaki M, Konoshima T, Kozuka M, Tokuda H. Anti-tumorpromoting activities of euglobals from Eucalyptus plants. Biol Pharm Bull 1995;18:435–8.10.1248/bpb.18.435Search in Google Scholar PubMed
25. Kirton LG. Laboratory and field tests of the effectiveness of the lemon-Eucalyptus extract, Citriodiol, as a repellent against land leeches of the genus Haemadipsidae. Ann Trop Med Parasitol 2005;99:695–714.10.1179/136485905X51517Search in Google Scholar PubMed
26. Agarwal AK. Therapeutic efficacy of an herbal gel for skin affection in dogs. Indian Veterinary J 1997;74:417–9.Search in Google Scholar
27. Pavneesh M, Pandey SK, Chhabra MB, Saxena MJ. Efficacy of a tropical herbal gel for mastitis control. Int J Animal Sci 1996;11:289–91.Search in Google Scholar
28. Joshi HC, Kumar M, Saxena MJ, Chhabra MB. Herbal gel for the control of subclinical mastitis. Indian J Dairy Sci 1996;49:631–4.Search in Google Scholar
29. Rahimi-Nasrabadi M, Nazarian S, Farahani H, Reza G, Koohbijari F, Ahmadi F, et al. Chemical composition, antioxidant and antibacterial activities of the essential oil and methanol extracts of Eucalyptus largiflorens F. Muell. Inter J Food Proporties 2013;16:369–81.10.1080/10942912.2010.551310Search in Google Scholar
30. Rahimi-Nasrabadi M, Ahmadi F, Batooli H. Essential oil composition of Eucalyptus procera Dehnh. leaves from central Iran. Nat Pro Res 2012;26:637–42.10.1080/14786419.2010.541875Search in Google Scholar PubMed
31. Rahimi-Nasrabadi M, Ahmadi F, Batooli H. Chemical composition of esesntial oil and in vitro antioxidant activities of the essential oil and methanol extracts of Eucalyptus loxophleba. Nat Prod Res 2012;26:669–74.10.1080/14786419.2011.593516Search in Google Scholar PubMed
32. Inouye S, Takizawa T, Yamaguchi H. Antibacterial activity of essential oils and their major constituents against respiratory tract pathogens by gaseous contact. J Antimicrob Chemother 2001;47:565–73.10.1093/jac/47.5.565Search in Google Scholar PubMed
33. Farah A, Satrani B, Fechtal M, Chaouch A, Talbi M. Composition chimique et activité antibactérienne et antifongique des huiles essentielles extraites des feuilles Eucalyptus camaldulensis et de son hybride naturel (clone 583). Acta Botanica Gallica 2001;148:183–90.10.1080/12538078.2001.10515886Search in Google Scholar
34. Takarada K, Kimizuka R, Takahashi N, Honma K, Okuda K, Kato T. A comparison of the antibacterial efficacies of essential oils against oral pathogens. Oral Microbiol Immunol 2004;19:61–4.10.1046/j.0902-0055.2003.00111.xSearch in Google Scholar PubMed
35. Wilkinson JM, Cavanagh HM. Antibacterial activity of essential oils from Australian native plants. Phytother Res 2005;19:643–6.10.1002/ptr.1716Search in Google Scholar PubMed
36. Mounchid K, Bourjilat F, Dersi N, Aboussaouira T, Rachidai A, Tantaoui-Elaraki A, et al. The susceptibility of Escherichia coli to essential oils of Romarinus officinalis and Eucalyptus globulus. Afr J Biotechnol 2005;4:1175–6.Search in Google Scholar
37. Schelz Z, Molnar J, Hohmann J. Antimicrobial and antiplasmid activities of essential oils. Fitoterapia 2006;77:279–85.10.1016/j.fitote.2006.03.013Search in Google Scholar PubMed
38. Adams RP. Identification of essential oil components by gas chromatography/quadrupole mass spectroscopy. Carol Stream IL: Allured Publ Crop, 2001.Search in Google Scholar
39. Bagci E, Dogan G. Composition of the essential oils of two Umbelliferae herbs (Artedia squamata and Malabaila secacul) growing wild in Turkey. J Essent Oil Bear Pl 2015;18:44–51.10.1080/0972060X.2014.1001184Search in Google Scholar
40. National committee for clinical laboratory standards (NCCLS). Performance standards for antimicrobial susceptibility testing: ninth informational supplement, 1999;19:21.Search in Google Scholar
41. Salem MZM, Ashmawy NA, Elansary HO, El-Settawy AA. Chemotyping of diverse Eucalyptus species grown in Egypt and antioxidant and antibacterial activities of its respective essential oils. Nat Prod Res 2015;29:681–5.10.1080/14786419.2014.981539Search in Google Scholar PubMed
42. Elaissi A, Rouis Z, Mabrouk S, Salah KB, Aouni M, Khouja ML, et al. Correlation between chemical composition and antibacterial activity of essential oils from fifteen Eucalyptus species growing in the Korbous and Jbel Abderrahman Arboreta (North East Tunisia). Molecules 2012;17:3044–57.10.3390/molecules17033044Search in Google Scholar PubMed PubMed Central
43. Traore N, Bouare S, Sidibe L,Somboro AA, Fofana B, Tangara O, et al. Antimicrobial activity of essential oils of Eucalyptus camaldulensis from Mali. Asian J Plant Sci Res 2014;4:69–73.Search in Google Scholar
44. Nikbakht MR, Rahimi-Nasrabadi M, Ahmadi F, Gandomi H, Abbaszadeh S. The chemical composition and in vitro antifungal activities of essential oils of five Eucalyptus species. J Essent Oil Bearing Plants 2015;18:666–77.10.1080/0972060X.2014.935061Search in Google Scholar
45. Ashour HM. Antibacterial, antifungal and anticancer activities of volatile oils and extracts from stems, leaves and flowers of Eucalyptus sideroxylon and Eucalyptus torquata. Cancer Biol Ther 2008;7:399–403.10.4161/cbt.7.3.5367Search in Google Scholar PubMed
46. Ghalem BR, Mohamed B. Antibacterial activity of leaf essential oils of Eucalyptus globulus and Eucalyptus camaldulensis. Afr J Pharm Pharmacol 2008;2:211–5.Search in Google Scholar
47. Elaissi A, Hadj SK, Mabrouk S, Mohamed LK, Chemli R, Skhiri FH. Antibacterial activity and chemical composition of 20 Eucalyptus species essential oils. Food Chem 2011;129:1427–34.10.1016/j.foodchem.2011.05.100Search in Google Scholar
48. Tyagi AK, Malik A. Antimicrobial potential and chemical composition of Eucalyptus globulus oil in liquid and vapour phase against food spoilage microorganisms. Food Chem 2011;126: 228–35.10.1016/j.foodchem.2010.11.002Search in Google Scholar
49. Pitarokili D, Tzakou O, Loukis A, Harvala C. Volatile metabolites from Salvia fruticosa as antifungal agents in soilborne pathogens. J Agric Food Chem 2003;51:3294–301.10.1021/jf0211534Search in Google Scholar PubMed
50. Sonboli A, Babakhani B, Mehrabian AR. Antimicrobial activity of six constituents of essential oil from Salvia. Z Naturforsch C 2006;61:160–4.10.1515/znc-2006-3-401Search in Google Scholar PubMed
51. Pattnaik S, Subramanyam VR, Bapaji M. Kole CR. Antibacterial and antifungal activity of aromatic constituents of essential oils. Microbios 1997;89:39-46.Search in Google Scholar
52. Tzakou O, Pitarokili D, Chinou IB, Harvala C. Composition and antimicrobial activity of the essential oil of Salvia ringens. Planta Medica 2001;67:81–3.10.1055/s-2001-10627Search in Google Scholar PubMed
53. Gliic SB, Milojevic SZ, Dimitrijevic SI, Orlovic AM, Skala DU. Antimicrobial activity of the essential oil and different fractions of Juniperus communis L. and a comparison with some commercial antibiotics. J Serb Chem Soc 2007;72:311–20.10.2298/JSC0704311GSearch in Google Scholar
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