Synergistic anti-candidal activity and mode of action of Mentha piperita essential oil and its major components

Abstract

Context: Mentha piperita L. (Lamiaceae) has been used in folk medicine since antiquity. Its essential oil (mint EO) and major bioactive components have antimicrobial properties but their mechanism of action is still not clear.

Objective: The present work aims to elucidate M. piperita’s anti-Candida activity and mode of action.

Materials and methods: Chemical constituents of mint EO were identified by GC-MS by injecting 0.1?ml sample in a splitless mode. MIC was determined by the broth dilution method. Synergy with fluconazole (FLC) was evaluated by checkerboard assay and FICI. Mid log phase cells harvested from YPD media were used for proton extrusion measurement and the rate of glucose-induced H⁺ efflux gives PM-ATPase activity. Cell membrane integrity was estimated by total ergosterol content and scanning microscopy at respective MIC and sub-MIC values. In vitro hemolytic activity was performed to rule out possible cytotoxicity of the test compounds.

Results: The MIC value of mint EO, carvone, menthol, and menthone was 225, 248, 500, and 4200?µg/ml, respectively. At their respective MICs, these compounds showed 47, 42, 35, and 29% decrease in PM-ATPase activity besides showing synergy with FLC. In case of FLC-resistant strains, the decrease in H⁺ efflux was by 52, 48, 32, and 30%, a trend similar to the susceptible cases. Exposed Candida cells showed a 100% decrease in the ergosterol content, cell membrane breakage, and alterations in morphology.

Discussion and conclusion: Our studies suggest that mint EO and its lead compounds exert antifungal activity by reducing ergosterol levels, inhibiting PM-ATPase leading to intracellular acidification, and ultimately cell death. Our results suggest that mint EO and its constituents are potential antifungal agents and need to be further investigated.     

Chemical composition of the essential oil from melissa

Different oil-samples of Melissa officinalis L. were analysed by capillary GC/MS, using fused silica columns and E.I.-Mass-spectrometry. Comparing the observed mass-spectra with those of a spectral collection, 70 compounds of the oil were identified. Geranial, neral, 6-methyl-5-hepten-2-one, citronellal, geranyl-acetate, beta-caryophyllene, and beta-caryophyllene-oxide comprise about 96%. The fingerprint of the capillary gas-chromatogramm permitted differentiation of the essential oil of Melissa officinalis, Cymbopogon winterianus and Nepeta cataria var. citriodora., as well as a standardisation of pharmaceutical preparations containing Melissa oil.     

Chemical composition of the essential oil from melissa.]

Different oil-samples of MELISSA OFFICINALIS L. were analysed by capillary GC/MS, using fused silica columns and E.I.-Mass-spectrometry. Comparing the observed mass-spectra with those of a spectral collection, 70 compounds of the oil were identified. Geranial, neral, 6-methyl-5-hepten-2-one, citronellal, geranyl-acetate, beta-caryophyllene, and beta-caryophyllene-oxide comprise about 96%. The fingerprint of the capillary gas-chromatogramm permitted differentiation of the essential oil of MELISSA OFFICINALIS, CYMBOPOGON WINTERIANUS and NEPETA CATARIA var. CITRIODORA., as well as a standardisation of pharmaceutical preparations containing Melissa oil.     

Chemical composition and antimicrobial activity of the essential oil of Rosemary

The composition of the essential oil of Rosemary was analyzed by gas chromatography-mass spectrometry (GC-MS). 22 components, which constitute 97.41% of the oil, were identified. The major constituents were 1,8-Cineole (26.54%) and α-Pinene (20.14%). Minimum inhibitory concentrations (MICs), minimal bactericidal concentration (MBC) and time-kill dynamic processes against three Gram-positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus and Bacillus subtilis), three Gram-negative bacteria (Proteus vulgaris, Pseudomonas aeruginosa and Escherichia coli) and two fungi (Candida albicans and Aspergillus niger) were determined for the oil, 1,8-Cineole and α-Pinene. The oil showed pronounced antibacterial and antifungal activity than 1,8-Cineole and α-Pinene against all of the tested microbes. Furthermore, the survival rates and morphological changes of S. aureus after treatment with different concentrations of the essential oil were assessed by flow cytometry (FCM) and atomic force microscopy (AFM).     

Chemical composition and analgesic activity of Senecio rufinervis essential oil

Context: Senecio rufinervis D.C (Asteraceae) is a tall aromatic herb, commonly found in Uttarakhand, India. No investigations on the biological activity of this plant have been published so far. Hence, this plant species became a subject of our scientific interest.

Objective: The aim of the study was to investigate the chemical composition and analgesic activity of Senecio rufinervis essential oil in mice using both thermal and chemical models of pain.

Materials and methods: Essential oil from dried leaves of Senecio rufinervis was extracted by steam distillation and then subjected to GC-MS analysis. Varying doses of essential oil were given to mice, 30?min prior to the induction of abdominal constrictions and determination of mean reaction time in hot-plate maintained at 55° ± 0.5°C.

Results: The main component detected in the essential oil of Senecio rufinervis was germacrene D (40.19%) followed by β-pinene (12.23%), β-caryophyllene (6.21%) and β-longipinene (4.15%). Essential oil exhibited significant and dose-dependent analgesic activity against acetic acid-induced writhing in mice. The percentage inhibition in number of writhes produced by 25, 50 and 75?mg/kg doses was, respectively, 69, 80 and 85%. The oil, at doses 50 and 75?mg/kg, significantly increased the mean latency in the hot-plate after 15 and 30?min of drug administration as compared to the control group.

Discussion and conclusion: The results depicted both central and peripheral analgesic activity of S. rufinervis essential oil which was attributed to the presence of terpenes.     

Chemical composition and antifungal activity of the essential oil of Thymbra capitata

The composition and the antifungal activity of the essential oil of Thymbra capitata on Candida, Aspergillus and dermatophyte strains were studied. Twenty-two samples of the essential oils from the aerial parts of the plant were obtained by hydrodistillation and analysed by GC and GC-MS. All samples are of the carvacrol type, with a high content of carvacrol (60.0 - 65.8 %) and its biogenetic precursors, gamma-terpinene (8.2 - 9.5 %) and p-cymene (6.0 - 7.5 %). The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity against Candida (7 clinical isolates and 3 ATCC type strains), Aspergillus (5 clinical isolates, 2 CECT and 2 ATCC type strains) and 5 dermatophyte clinical strains. To clarify its mechanism of action on Candida strains, the inhibition of germ tube and a flow cytometry assay with propidium iodide (PI) were used. The oil exhibited antifungal activity for all the tested strains, particularly for dermatophytes, with MIC values ranging from 0.08 to 0.32 microL/mL. Regarding Candida, concentrations lower than the MIC values prevented germ tube formation. After a short incubation time the cells incorporated quickly PI, meaning that the fungicidal effect is mainly due to direct lesion of the membrane.     

Chemical composition and antimicrobial activity of the essential oil of Artemisia lavandulaefolia

The chemical components of the essential oil obtained from Artemisia lavandulaefolia DC. were analyzed by GC-MS. Ninety-nine compounds accounting for 94.9 % of the essential oil were identified. The major compounds in the essential oil were beta-caryophyllene (16.1 %), cis-chrysanthenol (7.0 %), 1,8-cineole (5.6 %), borneol (5.3 %), trans-beta-farnesene (5.1 %), camphor (4.9 %), yomogi alcohol (4.5 %), alpha-terpineol (3.9 %), and alpha-humulene oxide (3.3 %). The essential oil and some of its major compounds were tested for antimicrobial activity against 15 different genera of oral bacteria. The essential oil of A. lavandulaefolia exhibited considerable inhibitory effects against all obligate anaerobic bacteria (MIC values, 0.025 to 0.05 mg/mL; MBC values, 0.025 to 0.1 mg/mL) tested, while its major compounds demonstrated different degrees of growth inhibition.     

中国沉香挥发油的化学成分与抗耐甲氧西林金葡菌活性

分析中国沉香的挥发油成分,并测试其抗耐甲氧西林金葡菌活性。采用水蒸气蒸馏法提取中国沉香挥发油进行GC/MS分析,峰面积归一化法计算各成分相对含量,采用NIST05和WILEY275L数据库匹配,以及将质谱图与文献数据进行对照的方法进行鉴定。采用滤纸片琼脂扩散法测试挥发油抗菌活性。挥发油对耐甲氧西林金葡菌显示强活性。共检测到66个色谱峰,其中30个化合物得到鉴定,占挥发油总量的59.80%。26个化合物被鉴定为倍半萜类化合物,占挥发油总量的54.26%。β-沉香呋喃（8.96%）,枯苏醇（7.82%）,（-）-jinkoh-eremol（5.04%）,沉香螺旋醇（4.53%）,白木香呋喃酸（4.09%）为主要的倍半萜。4个降倍半萜和其他一些倍半萜,如10-表-γ-桉叶油醇,α-沉香呋喃,epi-ligulyl oxide等为首次从中国沉香中检出。本文首次报道了中国沉香挥发油对耐甲氧西林金葡菌具有抗菌活性。     

Chemical composition and biological activities of essential oil of Beilschmiedia pulverulenta

Context: The ethnopharmacological study of Beilschmiedia indicates that several species are used for the treatment of various ailments.

Objective: This is the first study of the chemical composition of Beilschmiedia pulverulenta Kosterm (Lauraceae) essential oil and its antioxidant, antimicrobial, antityrosinase, anti-inflammatory, and anticholinesterase activities.

Materials and methods: The antioxidant activities were evaluated by β-carotene, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, ferric-reducing antioxidant power (FRAP), and phenolic content at different concentrations. The antimicrobial activities against Gram-positive and Gram-negative bacteria and fungi were revealed by disk diffusion and microdilution. The antityrosinase and anti-inflammatory activities were assayed against mushroom tyrosinase and lipoxygenase enzymes. The anticholinesterase activity was analyzed using acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes.

Results: Forty-two components were detected in B. pulverulenta oil with eugenol (45.3%) being the major component. The oil phenolic content and the FRAP were 660.1?mg gallic acid/g and 604.0?mg ascorbic acid/g, respectively. The oil gave an IC₅₀ value of 94.5?µg/mL and an inhibition of 93.9% in DPPH and β-carotene, respectively. The antimicrobial activity showed that the oil had strong activity against all Gram-positive bacteria with an minimum inhibitory concentration (MIC) value each of 62.5?µg/mL and moderate against all fungi with MIC and minimum bactericidal concentration (MBC) values each of 125?µg/mL. The oil showed significant antityrosinase and anti-inflammatory activities with 67.6 and 62.5% inhibition, respectively. In addition, the oil had moderate AChE (56.5%) and BChE (48.2%) activities.

Discussion and conclusion: The results show that the oil could potentially be used for nutraceutical industries, food manufactures, and therapeutic agents against various diseases such as inflammation and rheumatism.     

Chemical composition and antibacterial activity of essential oil of Artemisia iwayomogi

The chemical composition of the essential oil from Artemisia iwayomogi Kitamura was analyzed by means of GC and GC-MS. Eighty-five constituents were identified representing 96.23 % of the total oil. Camphor (19.31 %), 1,8-cineole (19.25 %), borneol (18.96 %), camphene (4.64 %), and beta-caryophyllene (3.46 %) were found to be the major components. Furthermore, the oil exhibited antibacterial activity against six Gram-(+) and six Gram-(-) bacteria in tests using the broth dilution method.     

Chemical composition and biological activities of Asimina triloba leaf essential oil

Leaf essential oil of Asimina triloba (L.) Dunal (F. Annonaceae) was found to be active against both human lung carcinoma and breast carcinoma cell lines. From this hydrodistillation extract, 37 components were identified by GC-MS analysis; sesquiterpenes dominated the oil composition (83%), with cadinene derivatives occurring in the greatest abundance (70%). Using the DDPH assay for antioxidant testing, the essential oil displayed moderate activity relative to vitamin E. These findings suggest that A. triloba essential oil may provide leads for active anticancer agents.     

Chemical composition and acetylcholinesterase inhibitory activity of Artemisia maderaspatana essential oil

Abstract

Context: To date, there are no reports to validate the Indian traditional and folklore claims of Artemisia maderaspatana L. (syn. Grangea maderaspatana L.) (Asteraceae) for the treatment of Alzheimer’s disease.

Objective: The present study characterizes the volatile components (non-polar compounds) of A. maderaspatana and evaluates its acetylcholinesterase inhibition potential.

Materials and methods: The essential oils (yield 0.06% v/w) were obtained from fresh aerial part of A. maderaspatana. The characterization of volatile components (non-polar compounds) was performed by GC–MS data and with those of reference compounds compiled in the spectral library of in-house database. The in vitro acetylcholinesterase (AChE) inhibition of the volatile organic constituents (VOC’s) of A. maderaspatana aerial part was evaluated in varying concentration ranges (0.70–44.75?µg/mL) with Ellman’s method.

Results: The major components were α-humulene (46.3%), β-caryophyllene (9.3%), α-copaene (8.2%), β-myrcene (4.3%), Z(E)-α-farnesene (3.7%), and calarene (3.5%). Chemical variability among other Artemisia spp. from different climatic regions of India and countries namely Iran and France was observed. The experimental results showed that diverse volatile organic constituents of A. maderaspatana have significant acetylcholinesterase inhibitory activity (an IC₅₀ value of 31.33?±?1.03?µg/mL). This is the first report on the inhibition of acetylcholinesterase properties of essential oil of A. maderaspatana obtained from fresh aerial part.

Conclusions: The present results indicate that essential oil of A. maderaspatana isolated from the northern region of India could inhibit AChE moderately. Therefore, the possibility of novel AChE inhibitors might exist in VOCs of this plant.     

Chemical composition and anti-inflammatory activities of essential oil from Trachydium roylei

Chemical composition, anti-inflammatory activity, and cytotoxicity of essential oils obtained from the aerial parts of Trachydium roylei were investigated in this study. The chemical composition of T. roylei essential oil was analyzed using gas chromatography mass spectrometry. Fifty-nine components, representing 98.87% of the oils, were characterized. The oils were predominated by aromatic compounds and monoterpene hydrocarbons, and the main components were myristicin (25.35%), β-phellandrene (22.95%), elemicine (7.69%), isoelemicin (5.48%), and cedrol (5.26%). The anti-inflammatory activity of the oil in lipopolysaccharide-stimulated murine RAW 264.7 cells was evaluated. The oils downregulated the production of proinflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-1β, and IL-6, and significantly increased the anti-inflammatory cytokine IL-10 levels. Results indicated that the oils effectively inhibited the secretion of nitric oxide and prostaglandin E2 in lipopolysaccharide-stimulated macrophages. Western blot analyses were performed to determine whether the inhibitory effects of the oils on proinflammatory mediators (nitric oxide and prostaglandin E2) were related to the modulation of inducible nitric oxide synthase and cyclooxygenase-2 expression. These findings suggest that T. roylei essential oils exert an anti-inflammatory effect by regulating the expression of inflammatory cytokines.     

Chemical composition and antibacterial activity of the essential oils from the medicinal plant Mentha cervina L. grown in Portugal

Mentha cervina is a medicinal plant traditionally used in Portugal in folk medicine, in different gastric disorders and inflammations of the respiratory tract. In order to validate those traditional uses, M. cervina essential oils (EOs) were characterized by GC and GC–MS and their antimicrobial activity was tested against 23 bacterial strains (including multiresistant strains). The EOs were dominated by the monoterpenes pulegone (52–75%), isomenthone (8–24%), limonene (4–6%), and menthone (1–2%). The antibacterial activity of these EOs was compared to that of the main components standards. The most effective antibacterial activity was expressed by the EOs against the Gram-negative bacteria, Escherichia coli and Acinetobacter baumanni, with MIC values of 1?mg/ml. The EOs complex mixtures were more active than the individual aromatic components supporting the hypothesis that the EOs antibacterial activity is a function of the synergistic effect of their different aromatic components. These results show the potential role of M. cervina EOs as antibacterial agents and validate the traditional use of this plant.     

Chemical composition and biological activities of extracts and essential oil of Boswellia dalzielii leaves

Context: Boswellia dalzielii Hutch. (Burseraceae) is an aromatic plant. The leaves are used for beverage flavouring.

Objective: This study investigates the chemical composition and biological activities of various extracts.

Materials and methods: The essential oil was prepared via hydrodistillation. Identification and quantification were realized via GC-MS and GC-FID. Consecutive extractions (cyclohexane, dichloromethane, ethyl acetate and methanol) were carried out and various chemical groups (phenolics, flavonoids, tannins, antocyanins and sugar) were quantified. The volatile compounds of organic extracts were identified before and after derivatization. Antioxidant, antihyperuricemia, anti-Alzheimer, anti-inflammatory and anticancer activities were evaluated.

Results: In the essential oil, 50 compounds were identified, including 3-carene (27.72%) and α-pinene (15.18%). 2,5-Dihydroxy acetophenone and β-d-xylopyranose were identified in the methanol extract. Higher phenolic (315.97?g GAE/kg dry mass) and flavonoid (37.19?g QE/kg dry mass) contents were observed in the methanol extract. The methanol extract has presented remarkable IC_50?=_?6.10?mg/L for antiDPPH, 35.10?mg/L for antixanthine oxidase and 28.01?mg/L for anti-5-lipoxygenase. For acetylcholinesterase inhibition, the best IC₅₀ (76.20 and 67.10?mg/L) were observed, respectively, with an ethyl acetate extract and the essential oil. At 50?mg/L, the dichloromethane extract inhibited OVCAR-3 cell lines by 65.10%, while cyclohexane extract inhibited IGROV-1 cell lines by 92.60%.

Discussion and conclusion: Biological activities were fully correlated with the chemical groups of the extracts. The ethyl acetate and methanol extracts could be considered as potential alternatives for use in dietary supplements for the prevention or treatment of diseases because of these extracts natural antioxidant, antihyperuricemic and anti-inflammatory activities.     

Chemical composition and antifungal activity of the essential oil of Origanum virens on Candida species

The composition and the antifungal activity of the essential oil of Origanum virens on Candida species were studied. The essential oil was obtained from the aerial parts of the plant by hydrodistillation and analyzed by GC and GC-MS. The oil was characterized by its high content of carvacrol (68.1 %) and its biogenetic precursors, gamma-terpinene (9.9 %) and p-cymene (4.5 %). The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity against Candida strains (7 clinical isolates and 3 ATCC type strains). The inhibition of germ tube formation and flow cytometry, using the fluorescent probe propidium iodide (PI), were used to evaluate their mechanisms of action. MIC and MLC values were similar for most tested strains, ranging from 0.16 to 0.32 microL/mL. Concentrations lower than MIC values strongly prevent germ tube formation. The fungicidal effect is primarily due to an extensive lesion of the membrane.     

Chemical composition and in vitro cytotoxic effects of the essential oil from Nectandra leucantha leaves

Abstract

Context: Nectandra (Lauraceae) species have been used in folk medicine as an antidiarrheal, analgesic, antifungal, etc., and have many pharmacological proprieties.

Objective: Investigation of the chemical composition and cytotoxicity of essential oil from Nectandra leucantha Nees & Mart. leaves. This is the first study involving N. leucantha reported in the literature.

Material and methods: The essential oil of N. leucantha leaves was obtained by hydrodistillation. Its chemical composition was determined using a combination of GC/FID, GC/MS, and determination of Kovats index (KI). In vitro cytotoxic activity was evaluated against six cancer cell lines – murine melanoma (B16F10-Nex2), human glioblastome (U-87), human cervical carcinoma (HeLa), human colon carcinoma (HCT), human breast adenocarcinoma (MCF7), and human cervical tumor (Siha) as well as against one non-tumorigenic cell line – human foreskin fibroblast (HFF).

Results: Thirty-three compounds were identified primarily sesquiterpenes (81.41%), the main compounds being bicyclogermacrene (28.44%), germacrene A (7.34%), spathulenol (5.82%), and globulol (5.25%). Furthermore, monoterpenes were also found in the analyzed oil (12.84%), predominantly α- and β-pinenes (6.59 and 4.57%, respectively). The crude essential oil displayed significant cytotoxic activity against B16F10-Nex2 (IC₅₀ 33?±?1?μg/mL) and U87 (IC₅₀ 75.95?±?0.03?μg/mL) and HeLa (IC₅₀ 60?±?12?μg/mL) cell lines. The main identified compound, bicyclogermacrene, displayed IC₅₀ ranging from 3.1?±?0.2 to 21?±?6?μg/mL.

Discussion and conclusion: The results indicate that the crude oils from leaves of N. leucantha displayed cytotoxic activity being bicyclogermacrene, the main compound identified in the crude oil responsible, at least in part, for this potential.