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Inhibitory effect of β-pinene, α-pinene and eugenol on the growth of potential infectious endocarditis causing Gram-positive bacteria


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Este estudo foi conduzido com a proposta de avaliar a efetividade de eugenol, b-pineno e a-pineno em inibir o crescimento de cepas de bactérias Gram-positivas potencialmente causadoras de endocardite infecciosa. A Concentração Inibitória Mínima-CIM dos fitoconstituintes foi determinada através do método de difusão em meio sólido, enquanto a interferência da CIM sobre a viabilidade celular bacteriana foi avaliada através da contagem de células viáveis. Cepas de Staphylococcus aureus, S. epidermidis, Streptococcus pneumoniae e S. pyogenes foram utilizadas como microrganismos teste nos ensaios antimicrobianos. Os fitoconstituintes ensaiados mostraram efetividade em inibir todas as cepas bacterianas utilizadas como microrganismos testes apresentando valores de CIM entre 2.5 e 40 µL/mL. Eugenol apresentou os menores valores de CIM, os quais estiveram entre 2,5 e 5 µL/mL para a maioria das cepas bacterianas. Os valores de CIM encontrados para os fitoconstituintes foram capazes de inibir a viabilidade celular de S. aureus causando uma total eliminação do inóculo bacteriano em um tempo máximo de 24 horas de exposição. Estes dados mostram o intenso potencial antibacteriano dos fitoconstituintes ensaiados e suportam sua possível e racional aplicação na terapia antimicrobiana.
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Revista Brasileira de Ciências Farmacêuticas
Brazilian Journal of Pharmaceutical Sciences
vol. 43, n. 1, jan./mar., 2007
Inhibitory effect of ββ
β-pinene, αα
α-pinene and eugenol on the growth of
potential infectious endocarditis causing Gram-positive bacteria
Aristides Medeiros Leite1, Edeltrudes de Oliveira Lima2 , Evandro Leite de Souza3, Margareth de
Fátima Formiga Melo Diniz1, Vinícius Nogueira Trajano2, Isac Almeida de Medeiros1
1Laboratório de Tecnologia Farmacêutica, Universidade Federal da Paraíba, João Pessoa, 2Laboratório de Micologia,
Departamento de Ciências Farmacêuticas, Centro de Ciências da Saúde, Universidade Federal da Paraíba,
João Pessoa, 3Departamento de Nutrição, Centro de Ciências da Saúde, Universidade Federal da Paraíba,
João Pessoa
This study was led with the purpose of evaluating the effectiveness
of eugenol, β-pinene and α-pinene in inhibiting the growth of
potential infectious endocarditis causing gram-positive bacteria.
The phytochemicals Minimum Inhibitory Concentration-MIC was
determined by solid medium diffusion procedure, while the
interference of the MIC values on the bacterial cell viability was
performed by viable cells count. Staphylococcus aureus, S.
epidermidis, Streptococcus pneumoniae and S. pyogenes strains were
used as test microorganisms. The assayed phytochemicals showed
effectiveness in inhibiting all assayed bacteria strains presenting
MIC values between 2.5 and 40 μL/mL. Eugenol showed the lowest
MIC values which were between 2.5 and 5 μL/mL for the most
bacteria strains. MIC values found to the phytochemicals were
able to inhibit the cell viability of S. aureus providing a total
elimination of the bacteria inoculum in a maximum time of 24 hours
of exposure. These data showed the interesting antibacterial
property of the assayed phytochemicals and support their possible
and rational use in the antimicrobial therapy.
• Endocarditis
• Gram positive bacteria
• Phytochemicals
• Antibacterial activity
E.L. Souza
Rua Radialista Antônio Assunção de
Jesus, 680/102,
58052-230 - João Pessoa - PB, Brasil
Infectious endocarditis (IE) is an infectious disease
attacking mainly the heart valves endocardium. Most ca-
ses of IE has been related to infections caused by
Streptococcus and Staphylococcus genus, although
bacteria inserted in the HACEK group (Haemophillus
parainfluenzae, H. aphrophilus, H. paraphrophilus, H.
influenzae, Actinobacillus actinomycetemcomitans,
Cardiobaccterium hominis, Eikenella corrodens,
Kingela kingae and K. denitrificans) have presented an
emerging importance as IE causing agents (Baddour et
al., 2005; Bashore et al., 2006). Fungi can act as IE
etiological agents in immunosuppressed people and/or in
catheter and valve prosthesis users (Niwa et al., 2003;
Watanabe et al., 2003; Anguera et al., 2005).
A. M. Leite, E. O. Lima, E. L. Souza, M. F. F. M. Diniz, V. N. Trajano, I. A. Medeiros122
Even regarding the advances in the clinical therapy the
IE still presents a high mortality rate (20% to 30% of the
cases). It has been related to the development of antibiotic
resistance by IE causing agents, mainly when regarded the
Staphylococcus genus because the appearance of methicillin-
resistant Staphylococcus aureus (MRSA) (Nakatani et al.,
2003; Ishiwada et al., 2005). Some researchers have
reported that the rising of MRSA strains has been responsible
for an increase in the action of Staphylococcus genus as IE
causing agent. On the other hand, the participation of
Streptococcus genus in IE etiology has decreased (Ako et al.,
2003; Pigrau et al., 2005; Ferreiros et al., 2006).
Currently there has been an increasing interest in
studying the biological properties of plant and derivatives
in order to discover alternative biologically active
compounds (Seidil, 2000; Araújo et al., 2004; Lima et al.,
2005). Plant products have received a renewed interest in
their use as alternative source of antimicrobial
compounds because the uncontrolled use of the
antimicrobial chemotherapy (Dorman, Deans, 2000). The
successful history of microbial chemocontrol lies in the
continuous rising of microbial strains with resistance to
the classical antibiotics (Notermans, Hoogenboon-
Verdegaal, 1992). Researches regarding the antimicrobial
activity of phytochemicals have been yet little emphasized
being the most studies addressed to evaluate the
antimicrobial effect of essential oils and extracts (Nasci-
mento et al., 2000; Souza et al., 2005).
This study aimed to evaluate the effectiveness of
eugenol, β-pinene and α-pinene in inhibiting the growth of
Gram-positive bacteria known as potential IE etiological
Eugenol, α-pinene and β-pinene were supplied by
Department of Pharmaceutical Sciences, State University
of Ponta Grossa, Paraná, Brazil. The phytochemicals were
tested at concentrations ranging from 160 to 1.25 μL/mL,
and the solutions were prepared prior to the antimicrobial
assays according to Souza et al. (2007). Molecular
structures of the phytochemicals are shown in Figure 1.
Bacteria strains
Staphylococcus aureus ATCC 13150, S. aureus ATCC
6538, S. aureus ATCC 25932, S. aureus ATCC LB 126,
S. epidermidis SSI 1, S. epidermidis ATCC 12228,
Streptococcus pyogenes ATCC 19615, Streptococcus
pyogenes ATCC 8668 and S. pneumoniae ATCC 11773 were
used as test microorganisms. These strains were supplied by
Laboratory of Clinical Bacteriology, Department of
Pharmaceutical Sciences, Health Sciences Center, Federal
University of Paraíba, Brazil. Stock cultures were maintained
on nutrient agar slants at 4 °C. Inocula used in antimicrobial
assays were obtained from overnight cultures grown on
nutrient agar slants at 37 °C and diluted in sterile saline
solution (0.85 % w/v) to have a final concentration of 106
colony forming unity (cfu)/mL (adjusted according to the
turbidity of 0.5 McFarland scale tube).
Determination of the Minimum Inhibitory
Microplate bioassay was used to determine the
Minimum inhibitory concentration - MIC of the assayed
phytochemicals. For this was used a microplate with 96
wells (flatted bottom) and cap. The 96-well microplates
were prepared dispensing into each well 100 μL of doubled
strength nutrient broth inoculated with 1 mL of the
bacterium inoculum prior the assay (1:9 v/v). 100 μL of the
phytochemical solution with their respective concentration
was transferred into seven consecutive wells. Final volume
in each well was 200 μL. The solution having the highest
concentration was added into the first well and the lowest
concentration was added into the penultimate well. The last
well contained 200 μL of nutrient broth inoculated with the
bacterium inoculum was used as positive control (strain
viability). The microplate was asseptically sealed, followed
by mixing on plate shaker (300 rpm) for 30 s, and incubated
at 28 – 30 °C/48 h (Viljoen et al., 2003; Sahin et al., 2004).
Antibacterial activity was detected using a colorimetric
method by adding 200 μL of resauzurin staining (0.1 %)
aqueous solution in each well at the end of the incubation
period. MIC was defined as the lowest phytochemical
concentration able to inhibit the bacteria growth, as
FIGURE 1 - Molecular structures of phytochemicals used
in the antimicrobial assays.
α-pinene β-pineneeugenol
Inhibitory effect of β-pinene, α-pinene and eugenol 123
indicated by resauzurin staining (bacteria died cells are not
able to change the staining color by visual observation –
blue to red) (Palomino et al., 2002; Burt, Reinders, 2003).
Kill time study
Kill time study was carried out with MIC values
previously found in the microplate bioassay. For this was
used the viable cells count method. 5mL of double strength
nutrient broth was inoculated with 1mL of the bacterium
suspension (approximately 106 cfu/mL). After that, 4mL of
the phytochemical solution, with concentration adjusted to
provide a phytochemical final concentration similar to the
MIC previously determined, was added to the system and
followed by shaking for 30 s using Vortex. The system was
incubated at 37 °C. At different time intervals (1, 2, 4, 8,
12 and 24 hs) of exposure, 1mL of the suspension was
serially diluted (10-1 – 10-5) in sterile peptone water
(0.1% w/v) and inoculated on nutrient agar Petri dishes for
24 h at 37 °C (Viljoen et al., 2003; Souza et al., 2007). The
mean number of colonies (cfu/mL) was counted and
compared with that found in the control assay in which the
essential oil solution was replaced by sterile distilled water.
The results were expressed in log of cfu/mL.
Statistical analysis
Statistical analysis was performed to determine
significant differences (P<0.05) by Tukey test in the
bacteria kill time assays. For this was used Sigma stat 2.03
computer program.
MIC values found for eugenol, α-pinene and β-pinene
are shown in Table 1. The assayed phytochemicals presented
interesting antimicrobial potential noted by low MIC values.
MIC values oscillated between 2.5 (eugenol x S. pneumoniae
ATCC 11773) to 40 μL/mL (β-pinene x S. epidermidis
ATCC 12228). All assayed bacteria strains were sensitive to
the phytochemicals. On the other hand, some strains
presented resistant behavior to the standard antibiotics,
mainly to gentamicin. Eugenol provided the most intense
antibacterial effect showing MIC values between 2.5 to
5 μL/mL for the most bacteria strains. S. aureus presented
as the most resistant bacterium with MIC values between 10
and 20 μL/mL for the tested phytochemicals. For the other
bacteria species were found MIC values oscillating between
2.5 to 5 μL/mL for most interactions.
TABLE I - MIC of some phytochemicals on potential infectious endocarditis causing gram-positive bacteria
Bacteria Phytochemicals (μL/mL) Penicillin Gentamicin
Eugenol β-pinene α-pinene (10 μg/mL) (10 μg/mL)
S. aureus 10 20 20 S R
ATCC 13150
S. aureus 10 20 20 S S
ATCC 6538
S. aureus 10 20 20 S S
ATCC 25923
S. aureus 10 20 10 S S
LB 126
S. epidermidis 520 5 SS
S. epidermidis 540 5 SS
ATCC 12228
S. pyogenes 520 5 SR
ATCC 19615
S. pyogenes 520 10 SR
ATCC 8668
S. pneumoniae 2.5 20 5 R S
ATCC 11773
S: sensitive; R: resistant
A. M. Leite, E. O. Lima, E. L. Souza, M. F. F. M. Diniz, V. N. Trajano, I. A. Medeiros124
Figure 2, 3 and 4 show the effect of eugenol,
β-pinene and α-pinene MIC values on the S. aureus
ATCC 6538 cell viability. S. aureus was chosen to be
included in the kill time assays because it is known as the
main etiological agent of IE acquired at the community or
in nosocomial environment (Niwa et al., 2003; Ishiwada
et al., 2005). Phytochemicals MIC values were able to
cause a significant (p<0.05) inhibition of S. aureus cell
viability providing a bactericidal effect in a maximum
time of 24 hours of exposure. Most intense inhibitory
effect was showed by β-pinene and eugenol causing a total
elimination of the initial bacterial inoculum after 8 hours
of exposure. β-Pinene and eugenol presented a
bacteriostatic effect until 2 hours of exposure and from
this time on it was established a progressive decrease in
the bacteria cell count. α-pinene provided a bacteriostatic
effect until 4 hours of exposure being established its cidal
effect after 24 hours of exposure.
Some researches have found an antimicrobial
effectiveness in phytochemicals, although these data still
are considered as incipient when compared to the
availability of researches regarding the antimicrobial
properties of plant extracts and essential oils (Vasquez et
al., 2001; Nostro et al., 2004). Gayoso et al. (2004) and
Lima et al. (2005) found antimicrobial effectiveness of
pinenes against moulds and pathogen yeasts providing a
cidal effect between 2 and 5 hours of exposure. Hao et al.
(1998) reported antimicrobial activity of eugenol on Gram
positive bacteria, including S. aureus strains.
Phytochemicals are small organic biomolecules
generally hydrophobic and designated as naturally
occurring antibiotics. Cytoplasm membrane coagulation,
breakdown of protons motive force, breakdown of electron
flux and active transport unbalance are some events
responsible for providing the antimicrobial property of
phytochemicals (Sikkema, 1995; Carlson et al., 2002).
These biological events have been believed for no occurring
separately being some of them activated as consequence of
other ones (Sikkema, 1995; Burt, 2004).
Our data show the intense antimicrobial potential
of eugenol, β-pinene and α-pinene which were able to
inhibit significantly the growth and cell viability of
potential infectious endocarditis causing gram-positive
bacteria. These results support the recognizing of
phytochemicals as alternative antimicrobial compounds
to be used in pharmaceutical formulations used in the
antibacterial therapy. Further researches are needed to
FIGURE 3 - Effect of β-pinene (20 μL/mL) on the S. aureus
ATCC 6538 viable cells number.
Log cfu/mL
FIGURE 2 - Effect of eugenol (10 μL/mL) on the S. aureus
ATCC 6538 viable cells number.
1 2 4 8 12 24
Log cfu/mL
FIGURE 4 - Effect of α-pinene (20 μL/mL) on the S.
aureus ATCC 6538 viable cells number.
Log cfu/mL
Inhibitory effect of β-pinene, α-pinene and eugenol 125
evaluate their antimicrobial effectiveness against
pathogen microorganisms able to act as etiological
agents of different infections diseases, as well as
regarding their toxicological and pharmacological
Efeito inibitório de eugenol, β-pineno e α-pineno
sobre o crescimento de bactérias Gram-positivas
potencialmente causadoras de endocardite infecciosa
Este estudo foi conduzido com a proposta de avaliar a
efetividade de eugenol, β-pineno e α-pineno em inibir o
crescimento de cepas de bactérias Gram-positivas poten-
cialmente causadoras de endocardite infecciosa. A Con-
centração Inibitória Mínima-CIM dos fitoconstituintes foi
determinada através do método de difusão em meio sóli-
do, enquanto a interferência da CIM sobre a viabilidade
celular bacteriana foi avaliada através da contagem de
células viáveis. Cepas de Staphylococcus aureus, S.
epidermidis, Streptococcus pneumoniae e S. pyogenes fo-
ram utilizadas como microrganismos teste nos ensaios
antimicrobianos. Os fitoconstituintes ensaiados mostra-
ram efetividade em inibir todas as cepas bacterianas uti-
lizadas como microrganismos testes apresentando valores
de CIM entre 2.5 e 40 μL/mL. Eugenol apresentou os
menores valores de CIM, os quais estiveram entre 2,5 e
5 μL/mL para a maioria das cepas bacterianas. Os valo-
res de CIM encontrados para os fitoconstituintes foram
capazes de inibir a viabilidade celular de S. aureus cau-
sando uma total eliminação do inóculo bacteriano em um
tempo máximo de 24 horas de exposição. Estes dados
mostram o intenso potencial antibacteriano dos
fitoconstituintes ensaiados e suportam sua possível e ra-
cional aplicação na terapia antimicrobiana.
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Recebido para publicação em 09 de agosto de 2006.
Aceito para publicação em 28 de fevereiro de 2007.
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... Eugenol is found to be effective against various gram-positive and negative bacteria [65][66][67]. ...
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The inclination of industry towards the naturally extracted raw materials is increasing to ensure the replacement of petroleum-based raw materials. “Eugenol” is a naturally extracted compound that serves as an efficient raw material for various polymers. It is the chemical structure of eugenol that enables it to get functionalized thereby making it potential for incorporation in polymers. The presence of aromatic ring and allyl group ensures the stability and resistivity against the factors which are favourable to the microbial colonization over the surface of the product. This enables the polymers incorporated with eugenol to impart better barrier properties to the product thereby enhancing its shelf life. Thus, it was applied in the polymer, coating as well as in the packaging industry. The study deals with the extraction, properties, and application of eugenol as raw material, in the packaging and the coating industry. Various extraction methods of eugenol have been discussed as conventional, non-conventional, and green technology. It is obtained naturally from plants such as tulsi leaves, clove buds, cinnamon bark, and turmeric. Several properties of eugenol such as solubility, toxicity, antimicrobial, and antifungal properties are discussed. The discussion of the incorporation of Eugenol with various polymers such as polyesters, polyurethanes, polyacrylates, epoxy, polyolefins and subsequent improvements in their properties has been discussed. It was also incorporated with oils and certain biopolymers like starch and cellulose. Eugenol used as an additive and its various properties in each application are discussed. Graphical abstract
... [6,12] α-pinene, as the main component of essential oils from aromatic coniferous trees, [13] presents various therapeutic effects including anti-inflammatory, anticancer, and antibacterial activities. [14][15][16] Recent studies have focused on the capacity of α-pinene in modulating neurobehavioral responses. It has been reported that chronic oral administration of α-pinene suppresses 6-hydroxydopamine-induced passive avoidance learning and memory impairment in rats. ...
Background: This study investigated the effect of central administration of α-pinene and the interaction of α-pinene with GABAA receptor on pulpal nociception-induced changes in learning and memory performances in rats. Materials and Methods: Sixty-six adult male Wistar rats were used. Pulpal nociception was induced by intradental application of capsaicin (100 μg/rat). α-pinene (0.1, 0.2, and 0.4 μg/rat) was injected centrally 10 min before the administration of capsaicin. In addition, α-pinene (0.4 μg/rat) was co-injected with bicuculline (0.5 μg/rat). Spatial and passive avoidance learning and memory were assessed using Morris water maze (MWM) and shuttle box tasks, respectively. Results: Experimental results of the MWM test showed that capsaicin increases escape latency and distance traveled to the hidden platform (P < 0.01). The effect was prohibited by α-pinene at the dose of 0.4 μg/rat. Moreover, capsaicin-treated animals spent less time in the target zone than capsaicin + α-pinene (0.4 μg/rat)-treated rats (P < 0.05). In the shuttle box test, α-pinene (0.2 μg and 0.4 μg) prevented an increased number of acquisition trials and time spent in the dark chamber induced by capsaicin, whereas it increased step-through latency (P < 0.01). However, the effects of α-pinene (0.4 μg/rat) in both tests were prohibited by bicuculline (0.5 μg/rat). Conclusion: The data showed that central administration of α-pinene might reduce pulpalgia-induced learning and memory impairment, at least partially, via modulation of GABAA receptors.
... (Esatbeyoglu et al. 2015) Numerous other volatiles (2-hexenal, (E), α-pinene limonene, guaiacol, etc.) present in the stem oil exhibit antimicrobial activity. (Leite et al. 2007;Kim et al. 1995) α-Pinene is a potent antiosteoarthritic drug and also possesses anti-inflammatory and anticatabolic effects. (Rufino et al. 2014) In peritoneal macrophages, it suppresses MAPKs and NF-B pathways, demonstrating anti-inflammatory action. ...
Senna occidentalis (Coffee Senna) is a renowned medicinal plant that has traditionally been used to treat fever, worms, snakebites, abscesses, liver disorders, and respiratory infections due to its efficacy in fighting against several disorders. Previously, volatile oils from its leaf and fruit have been investigated for their antimicrobial potential. However, in this study, the volatile composition and antibacterial activity of the stem of Senna occidentalis were reported for the first time. The volatile oil was extracted by microwave-assisted extraction that produced a yield of 0.086%, and a total of 19 compounds were successfully identified that accounted for 97.42% of total oil. Most dominant compounds were methyl salicylate (18.08%), furfural (16.94%), 5-Methylfurfural (13.61%), trans-isoeugenol (11.78%), p-vinyl guaiacol (9.91%) and furfuryl acetate (4.68%). Using the Agar Well diffusion method, this oil was further evaluated for the antibacterial potential against three well-known pathogenic strains, where very promising activity was observed against two strains of methicillin-resistant Staphylococcus aureus (27 mm and 26 mm) and Klebsiella pneumoniae (21 mm). Hence, the stem oil of Coffee Senna can be considered a potent source of natural antimicrobial compounds that may also be used for the treatment of various pathogenic diseases caused by these microbes.
... zeae, Pectobacterium carotovorum subsp. Carotovorum Pcc21, Salmonella typhimurium, Vibrio parahaemolyticus, Leuconostoc carnosum, Enterococcus faecalis, Weissella viridescens, Lactobacillus plantarum, Leuconostoc brevis, Leuconostoc citreum, Mycobacterium tuberculosis, Staphylococcus epidermis, Streptococcus pyogenes, Streptococcus pneumoniae, Streptococcus mutans, Streptococcus sanguinis, Streptoccus sobrinus, Streptococcus criceti, Streptococcus anginosus, Streptococcus gordonii, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Prevotella intermedia, Porphylomonas gingivalis, Streptococcus milleri, Streptococcus mitis, Prevotella buccae, Prevotella oris, and Prevotella intermedia (Karapinar and Esen Aktu g, 1987;Didry et al., 1994;Leite et al., 2007;Tippayatum and Chonhenchob, 2007;Moon et al., 2011;Zheng et al., 2013;de Almeida et al., 2019;Takahashi et al., 2021). ...
Clove (Syzygium aromaticum) is one of the most valuable spices that has been widely used for many medicinal purposes and as a food preservative in recent years. The major bioactive compound found both in clove spice and clove essential oil is eugenol (4-all-methoxyphenol C10H12O2) with a ratio of 85%–95%. However, side effects of this alkylphenol on human and animal health have been known for decades. Its cytotoxicity and genotoxicity are the most important factors that limit the consumption of both eugenol and clove by humans. World Health Organization (WHO) specified the acceptable daily intake (ADI) of eugenol which is a maximum of 2.5 mg per kg body weight. Different mechanisms of action have been proposed to explain cytotoxicity of eugenol: (a) oxidation of eugenol by peroxidases generates quinone methide intermediate which is toxic to hepatocytes; (b) high affinity of eugenol to plasma membranes due to its highly lipophilic nature results in cell damage; (c) the influence of eugenol on uncoupling of oxidative phosphorylation in mitochondria; (d) the prooxidant activity of eugenol triggers the formation of oxygen-free radicals that contribute to tissue damage; and (e) protein deactivation and consequently toxicity due to binding of lysine to eugenol. Nevertheless, more detailed in vitro and in vivo studies are still required to clearly reveal the mechanism of action of clove’s toxicity on human health. Toxic effects of spices and their essential oils may occur depending on their areas of use and they are usually dose-dependent.Toxic constituents are generated in three classes as low toxicity compounds, components less harmless than first class, and high toxicity compounds, respectively. This chapter discusses the toxicity of clove spice and eugenol due to their antifungal, antibacterial, and pharmaceutical uses.
... Indeed, αand β-pinene have been reported to exhibit very low activity against a panel of microorganisms. MICs values were varied between 7.5 and 20.0 mg/mL against S. aureus, E. coli and E. faecalis (Dorman and Deans, 2000;Sonboli et al., 2006;Jung, 2009;Leite et al., 2007). Our results agree with those of Bourkhiss et al. in (2007b). ...
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The essential oil from aerial parts of Tetraclinis articulata (Vahl) Masters, obtained byhydrodistillation was analyzed by GC, GC/MS and 13C-NMR and evaluated for antimicrobialactivity. The essential oil was rich in monoterpenes which α-pinene, bornyl acetate andcamphor being the main constituents.Three essential oils were tested against Staphylococcusaureus, Enterococcus faecalis, Pseudomonas aeruginosa, Escherichia coli, Klebsiellapneumoniae, Candida albicans, Aspergillus fumigatus and Aspergillus flavus and theminimum inhibitory concentration was determined.The tested oils have been shown topossess inhibitory action in the range from 1 to 6 µL/mL against Aspergillus fumigatus, A.niger and Staphylococcus aureus. However, essential oil with camphor as major componentwas the most interesting, with CMIs ranging between 1 and 3 µL/mL. While, essential oilwith α-pinene as major compound, remains the less effective, with CMIs ranging between 2and 6 µL/mL.
... The activity shown by the essential oil of this plant could also be attributed to the synergistic effect of some of its minor components. Earlier reports have shown that components such isocaryophyllene, which in minor composition could also elicit good antimicrobial activities 35,36,37 ...
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The essential oil of air-dried leaves of Pinus sylvestris obtained through hydro-distillation was characterized by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry analyses (GC-MS). The oil yielded 0.78% per dry weight of sample. The oil was composed majorly of mono-and sesquiterpenoids. The major components of the essential oil of P. sylvestris were humulene (13.24%), α-guaiene (11.57%), allo-ocimene (9.40%), terpinolene (8.84%), caryophyllene (8.84%), and terpineol (5.02%). The air-dried leaf oil showed strong activity against Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae, as well as a promising antioxidant potency. To our knowledge, this is the first report concerning chemical composition and antimicrobial activities of the essential oil from Pinus sylvestris. (
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This work presents the results ofa study which concerns the influence of rotating magnetic field (RMF) on the antibacterial performance of commercial pine essential oil. A suspension of essential oil in saline solution and Escherichia coli were exposed to the rotating magnetic Afield (the frequency of electrical current supplied by a RMF generator f = 1–50 Hz; the averaged values of magnetic induction in the cross-section of the RMF generator B = 13.13 to − 19.92 mT, time of exposure t = 160 min, temperature of incubation 37 °C). The chemical composition of pine (Pinus sylvestris L.) essential oil was determined by gas chromatography coupled with mass spectrometry (GC–MS). The main constituents were α-pinene (28.58%), β-pinene (17.79%), δ-3-carene (14.17%) and limonene (11.58%). The present study indicates the exposition to the RMF, as compared to the unexposed controls causing an increase in the efficacy of antibacterial properties of pine oil. We have shown that rotating magnetic fields (RMF) at a frequency, f, between 25 Hz to and 50 Hz increased the antimicrobial efficiency of oil a concentration lower than 50%.
In this project, a nano formulation have been used to tackle one of the most important environment problems which can be considered as a major threat to human health. We prepared some eco‐friendly nano‐structured lipid carriers as delivery agent to properly deliver an antibacterial agent (eugenol) into hospital wastewater in order to control the bacterial growth. Eugenol loaded nano‐structured lipid carriers were prepared by hot high‐speed homogenization. Then, the prepared nanocarriers were characterized using different techniques such as transmission electron microscopy, Fourier transform infra‐red, and dynamic scanning calorimetry. Turbidity assay and colony counting method were used to determine the ability of the prepared eugenol loaded nano‐structured lipid carriers to inhibit bacteria growth rate in the culture media and hospital wastewater, respectively. The mean size and zeta potential of NLC‐eugenol were 78.12± 6.1 nm and ‐29.43±2.21 mV, respectively. The results showed that the highest inhibitory effect of NLC‐eugenol in culture media was seen in standard and wild S. aureus strains (43.42% and 26.41 %, respectively) with concentration of 0.125 μM. The antibacterial activity of NLC‐eugenol in sterile wastewater on wild strains of bacteria showed that the most effective concentration to reduce bacteria amounts was 0.125 μM on wild S. aureus and E. fecalis strains (38% and 33.47 %, respectively) at 37 ° C. The NLC‐eugenol 0.125 μM showed the greatest effect on reducing total microbial agents equal to 28.66 % in hospital wastewater at 25°C. The highest antibacterial effect of 0.125 μM is due to egel phenomenon. Also, the mechanism of action of NLC‐eugenol is cell wall destruction and eventually cell death. The results showed that NLC‐eugenol with concentration of 0.125 μM can decline the wild bacteria strains in sterilized wastewater and hospital wastewater which can prove the great potential of the prepared eugenol loaded nano‐structured lipid carriers to control the bacteria growth.
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Opportunistic infections caused by yeasts have been characterized as emerging diseases all over the world and this has caused the search for new products capable of inhibiting the survival of their etiological agents. In this study the sensitivity of some yeast potentially causing infections to a-pinene, b-pinene, citral and eugenol was evaluated. All phytochemicals showed inhibitory action on the assayed yeast strains: Candida. albicans, C. tropicalis, C. guilliermondii, C. stellatoidea, C. krusei, C. parapsilosis and Cryptococcus neoformans, presenting their MIC values in the range of 1 and 4%. The phytochemicals presented effectiveness to provide high fungicide effect in a short time. These data support the possible use of some phytochemicals as useful tools to control the occurrence of opportunistic infections caused by yeasts.
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The aim of this study was to determine the sensitivity profile of mould strains isolated from foods to some essential oils and phytochemicals. The assayed mould strains were: Fusarium spp., Rhizopus spp., Aspergillus flavus, A. niger and Penicillium spp. According to results, Lippia alba N.E. Brown, Peumus boldus Molina, Lippia microphylla Phil., Citrus limon Risso and Cymbopogon citratus Stapf. essential oil and the phytochemicals citral, eugenol and mircene showed prominent antimould activity. Among the products that evidenced antimould activity, citral and eugenol showed the lowest minimum inhibitory concentrations, which was 1% and 4%, respectively, for the most of the tested mould strains.
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The present study was conducted to evaluate the antimicrobial activities, antioxidant and properties of essential oils and methanol extracts of Origanum vulgare ssp. vulgare plants. The chemical composition of a hydrodistilled essential oil of O. vulgare ssp. vulgare was analyzed by a GC/MS system. A total 62 constituents were identified. Caryophyllene and spathulenol were found to be the main constituents, followed by germacrene-D and α-terpineol. Antioxidant activity was measured employing two methods namely, scavenging of free radical DPPH and the inhibition of linoleic acid oxidation by methanol extracts and the essential oil of O. vulgare ssp. vulgare. Antioxidant studies suggested that methanol extract behaved as a strong free radical scavenger providing IC50 at only 9.9 μg/ml, whereas the oil showed weaker activity with IC50 at 8.9 mg/ml. Total phenolic constituents based on gallic acid equivalents revealed the presence of total soluble phenolics in the extract as 220 μg/mg dry extract (22%, w/w) and, most probably, they are responsible for the radical scavenging activity of methanol extracts. Methanol extract was not effectively able to inhibit linoleic acid oxidation and only 32% inhibition was achieved at 2 mg/ml concentration, far below that of the positive control (butylated hyroxytoluene, BHT) at the same concentration. However, 2.2 mg/ml essential oil solutions provided 50% inhibition in the linoleic acid oxidation test system.
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The antimicrobial activity of plant extracts and phytochemicals was evaluated with antibiotic susceptible and resistant microorganisms. In addition, the possible synergistic effects when associated with antibiotics were studied. Extracts from the following plants were utilized: Achillea millifolium (yarrow), Caryophyllus aromaticus (clove), Melissa offficinalis (lemon-balm), Ocimun basilucum (basil), Psidium guajava (guava), Punica granatum (pomegranate), Rosmarinus officinalis (rosemary), Salvia officinalis (sage), Syzygyum joabolanum (jambolan) and Thymus vulgaris (thyme). The phytochemicals benzoic acid, cinnamic acid, eugenol and farnesol were also utilized. The highest antimicrobial potentials were observed for the extracts of Caryophyllus aromaticus and Syzygyum joabolanum, which inhibited 64.2 and 57.1% of the tested microorganisms, respectively, with higher activity against antibiotic-resistant bacteria (83.3%). Sage and yarrow extracts did not present any antimicrobial activity. Association of antibiotics and plant extracts showed synergistic antibacterial activity against antibiotic-resistant bacteria. The results obtained with Pseudomonas aeruginosa was particularly interesting, since it was inhibited by clove, jambolan, pomegranate and thyme extracts. This inhibition was observed with the individual extracts and when they were used in lower concentrations with ineffective antibiotics.
Microbial transformations of cyclic hydrocarbons have received much attention during the past three decades. Interest in the degradation of environmental pollutants as well as in applications of microorganisms in the catalysis of chemical reactions has stimulated research in this area. The metabolic pathways of various aromatics, cycloalkanes, and terpenes in different microorganisms have been elucidated, and the genetics of several of these routes have been clarified. The toxicity of these compounds to microorganisms is very important in the microbial degradation of hydrocarbons, but not many researchers have studied the mechanism of this toxic action. In this review, we present general ideas derived from the various reports mentioning toxic effects. Most importantly, lipophilic hydrocarbons accumulate in the membrane lipid bilayer, affecting the structural and functional properties of these membranes. As a result of accumulated hydrocarbon molecules, the membrane loses its integrity, and an increase in permeability to protons and ions has been observed in several instances. Consequently, dissipation of the proton motive force and impairment of intracellular pH homeostasis occur. In addition to the effects of lipophilic compounds on the lipid part of the membrane, proteins embedded in the membrane are affected. The effects on the membrane-embedded proteins probably result to a large extent from changes in the lipid environment; however, direct effects of lipophilic compounds on membrane proteins have also been observed. Finally, the effectiveness of changes in membrane lipid composition, modification of outer membrane lipopolysaccharide, altered cell wall constituents, and active excretion systems in reducing the membrane concentrations of lipophilic compounds is discussed. Also, the adaptations (e.g., increase in lipid ordering, change in lipid/protein ratio) that compensate for the changes in membrane structure are treated.
Os processos infecciosos causados por agentes microbianos sao muito frequentes no Brasil, em consequencia de seu clima tropical. Esses processos afetam pele, pelos, unhas, mucosas, tecido subcutâneo, orgaos e sistemas. Como as infeccoes bacterianas e fungicas sao tratadas por meio da correcao de fatores predisponentes e de terapeutica medicamentosa, este estudo se propoe a avaliar o potencial antimicrobiano de oleos essenciais, obtidos de plantas medicinais, contra diversas especies microbianas conhecidas como potencialmente causadoras de infeccoes oportunistas, incluindo bacterias e fungos. Os resultados evidenciaram uma proeminente atividade antimicrobiana dos Oleos essenciais de Cinnamomum zeylanicum Biume a 4%, de Coniza bonariensis L. a 4% e de Lippia alba N. E. Brown a 8%, os quais inibiram o crescimento de 72%, 61% e 44%, respectivamente, das cepas testadas, apresentando halos de inibicao do crescimento microbiano entre 10 e 24 mm de diâmetro.
Alcohol extracts of angelica root, banana purée, bay, caraway seed, carrot root, clove (eugenol), marjoram, pimento leaf and thyme were applied to cooked chicken to determine their antimicrobial activities against Aeromonas hydrophilaand Listeria monocytogenes.Skinless chicken breast meat was cooked to an internal temperature of 85°C, allowed to cool to c. 5°C, then treated by surface application with plant extracts. Low (10cfug−1)or high (105cfug−1)populations of A. hydrophilaand L. monocytogeneswere applied and samples were stored at either 5 or 15°C for up to 14 or 7 days, respectively. Eugenol and pimento extracts were most effective in inhibiting growth of both bacteria. A. hydrophilawas the more sensitive to the two treatments, with 4log10cfug−1less growth occurring at 14 days at 5°C on eugenol-treated breast meat than on control samples. These results suggested that plant extracts might be useful as antimicrobials in cooked, ready-to-eat chicken meat.
Origanum vulgare L. has been known as having many therapeutic properties and its antimicrobial activity has currently received a renewed interest. This study aimed to verify the effectiveness of O. vulgare L. essential oil to inhibit the growth/survival of various food spoiling yeasts. Anti-yeast activity was studied by determining the MIC by solid medium diffusion and microplate bioassay, as well as observing the effect of the essential oil MIC on the yeast cell viability. O. vulgare essential oil showed effectiveness to inhibit the growth of all assayed yeasts with MIC values for the most ones of 20 and 0.6 μL/mL when determined, respectively, by solid medium diffusion and microplate bioassay. Solid medium diffusion MIC presented statistically significant inhibitory effects (P < 0.05) on yeast cell viability, mainly when interacting with Candida albicans and Candida krusei. On the other hand, the microplate MIC just provided statistically significant inhibitory effects on the cell viability when interacting with C. krusei. These data show the anti-yeast property of O. vulgare essential oil.