Screening of essential oils against oxacillin - resistant Staphylococcus aureus strains isolated from bovine mastitis / Screening de aceites esenciales frente a Staphylococcus aureus oxacilino - resistentes extraidos de aislados de mastitis bovina

Bovine mastitis is a disease wi th far - reaching consequences for the dairy industry. Staphylococcus aureus is a pathogen that is especially resistant to antibiotics. The objective of this study was to evaluate the antimicrobial activity of the essential oils Lippia citriodora (Lam.), Thy mus vulgaris (L), and a mixture of the essential oils Lippia citriodora and Thymus vulgaris (50/50 v/v), against isolates of oxacillin - resistant Staphylococcus aureus (n=15) of positive cases of bovine mastitis. For the statistical analysis, the IBM SPSS s tatistical package was used. The mixture of essential oils ( Lippia citriodora and Thymus vulgaris (50/50 v/v)) obtained the most significant antimicrobial activity in relation to pure essential oils. It is therefore concluded that the mixture of these oils boosts their antimicrobial activity ( p <0.05). The minimum inhibitory and bactericidal concentration of this mixture for the total isolations was 12 µL/L and 25 µL/mL, respectively.

La mastitis bovina es una enfermedad de gran impacto para la industria lechera. El Staphylococcus aureus es uno de los principales patógenos, especialmente aquellos resistentes a los antibióticos. El objetivo de este estudio fue evaluar la actividad antimicrobiana de los aceites esenciales de Lippia citriodora (Lam.), Thymus vulgaris (L), y una mezcla de aceites esenciales de Lippia citriodora y Thymus vulgaris (50/50 v/v), frente a aislamientos clínicos de Staph ylococcus aureus oxacilino - resistentes (n=15) de mastitis bovina. Se utilizó p rograma estadístico IBM SPSS y se concluyó la diferencia significativa a un p <0.05. La mezcla de aceites esenciales ( Lippia citriodora y Thymus vulgaris (50/50 v/v)), obtuvo la m ayor actividad antimicrobiana en relación a los aceites esenciales puros, se concluye que la mezcla de estos aceites potencia su actividad antimicrobiana ( p <0.019). La concentración mínima inhibitoria y bactericida de esta mezcla fue del 12 µL/mL y 25 µL/m L, respectivamente, y puede ser una alternativa terapéutica.

Supercritical Fluid-extracted Citrus aurantium L. var. amara Engl. Essential Oil Nanoemulsion: Preparation, Characterization, and Its Sleep-promoting Effect.

To overcome the defects of Citrus aurantium L. var. amara Engl. essential oil (CAEO), such as high volatility and poor stability, supercritical fluid-extracted CAEO nanoemulsion (SFE-CAEO-NE) was prepared by the microemulsification method. Emulsifiers comprising Tween 80, polyoxyethylenated castor oil (EL-40), and 1,2-hexanediol, and an oil phase containing SFE-CAEO were used for microemulsification. We examined the physicochemical properties of SFE-CAEO-NE and steam distillation-extracted CAEO nanoemulsion (SDE-CAEO-NE), which were prepared using different concentrations of the emulsifiers. The mean particle size and zeta potential were 21.52 nm and -9.82 mV, respectively, for SFE-CAEO-NE, and 30.58 nm and -6.28 mV, respectively, for SDE-CAEO-NE, at an emulsifier concentration of 15% (w/w). SFE-CAEO-NE displayed better physicochemical properties compared with SDE-CAEO-NE. Moreover, its physicochemical properties were generally stable at different temperatures (-20-60℃), pH (3-8), and ionic strengths (0-400 mM). No obvious variations in particle size, zeta potential, and Ke were observed after storing this nanoemulsion for 30 days at 4℃, 25℃, and 40℃, suggesting that it had good stability. The sleep-promoting effect of SFE-CAEO-NE was evaluated using a mouse model of insomnia. The results of behavioral tests indicated that SFE-CAEO-NE ameliorated insomnia-like behavior. Moreover, SFE-CAEO- NE administration increased the serum concentrations of neurotransmitters such as 5-hydroxytryptamine and γ-aminobutyric acid, and decreased that of noradrenaline in mice. It also exerted a reparative effect on the function of damaged neurons. Overall, SFE-CAEO-NE displayed a good sleep-promoting effect.

Chemical Composition, Anti-bacterial Activity and Molecular Docking Studies of Essential Oil Isolated from Sa Sam Nam (Launaea sarmentosa).

Launaea sarmentosa, also known as Sa Sam Nam, is a widely used remedy in Vietnamese traditional medicine and cuisine. However, the chemical composition and bioactivity of its essential oil have not been elucidated yet. In this study, we identified 40 compounds (98.6% of total peak area) in the essential oil via GC-MS analysis at the first time. Among them, five main compounds including Thymohydroquinone dimethyl ether (52.4%), (E)-α-Atlantone (9.0%), Neryl isovalerate (6.6%), Davanol D2 (isomer 2) (3.9%), and trans-Sesquisabinene hydrate (3.9%) have accounted for 75.8% of total peak area. The anti-bacterial activity of the essential oil against 4 microorganisms including Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa has also investigated via agar well diffusion assay. The results showed that the essential oil exhibited a strong antibacterial activity against Bacillus subtilis with the inhibition zones ranging from 8.2 to 18.7 mm. To elucidate the anti-bacterial effect mechanism of the essential oil, docking study of five main compounds of the essential oil (Thymohydroquinone dimethyl ether, (E)-α-Atlantone, Neryl isovalerate, Davanol D2 (isomer 2), and trans-Sesquisabinene hydrate) against some key proteins for bacterial growth such as DNA gyrase B, penicillin binding protein 2A, tyrosyl-tRNA synthetase, and dihydrofolate reductase were performed. The results showed that the main constituents of essential oil were highly bound with penicillin binding protein 2A with the free energies ranging -27.7 to -44.8 kcal/mol, which suggests the relationship between the antibacterial effect of essential oil and the affinity of main compounds with penicillin binding protein. In addition, the free energies of main compounds of the essential oil with human cyclooxygenase 1, cyclooxygenase 2, and phospholipase A2, the crucial proteins related with inflammatory response were less than diclofenac, a non-steroidal antiinflammatory drug. These findings propose the essential oil as a novel and promising anti-bacterial and anti-inflammatory medicine or cosmetic products.

Industrial Distillation Fractions of Garlic Essential Oil, Design, Synthesis, and Antifungal Activity Evaluation of Aliphatic Substituted Trisulfide Derivatives.

Garlic oil has a wide range of biological activities, and its broad-spectrum activity against phytopathogenic fungi still has the potential to be explored. In this study, enzymatic treatment of garlic resulted in an increase of approximately 50 % in the yield of essential oil, a feasible GC-MS analytical program for garlic oil was provided. Vacuum fractionation of the volatile oil and determination of its inhibitory activity against 10 fungi demonstrated that garlic oil has good antifungal activity. The antifungal activity levels were ranked as diallyl trisulfide (S-3)>diallyl disulfide (S-2)>diallyl monosulfide (S-1), with an EC50 value of S-3 against Botrytis cinerea reached 8.16 mg/L. Following the structural modification of compound S-3, a series of derivatives, including compounds S-4~7, were synthesized and screened for their antifungal activity. The findings unequivocally demonstrated that the compound dimethyl trisulfide (S-4) exhibited exceptional antifungal activity. The EC50 of S-4 against Sclerotinia sclerotiorum reached 6.83 mg/L. SEM, In vivo experiments, and changes in mycelial nucleic acids, soluble proteins and soluble sugar leakage further confirmed its antifungal activity. The study indicated that the trisulfide bond structure was the key to good antifungal activity, which can be developed into a new type of green plant-derived fungicide for plant protection.

In vitro and in vivo evaluation of the anti-infective potential of the essential oil extracted from the leaves of Plectranthus amboinicus (lour.) spreng against Klebsiella pneumoniae and elucidation of its mechanism of action through proteomics approach.

ETHNOPHARMACOLOGICAL RELEVANCE: Members of Plectranthus genus such as Plectranthus amboinicus (Lour.) Spreng is a well-known folkloric medicine around the globe in treating several human ailments such as cardiovascular, respiratory, digestive, urinary tract, skin and infective diseases. Its therapeutic value is primarily attributed to its essential oil. Although several properties of Plectranthus amboinicus essential oil have been documented, its mechanism of action and safety has not been completely elucidated. AIM OF THE STUDY: To investigate the anti-infective potential of Plectranthus amboinicus essential oil against Klebsiella pneumoniae using in vitro and in vivo bioassays and identify its mode of action. The study was conducted to scientifically validate the traditional usage of Plectranthus amboinicus oil and propose it as a complementary and alternative medication to combat Klebsiella pneumoniae infections due to emerging antibiotic resistance problem. MATERIALS AND METHODS: Plectranthus amboinicus essential oil was extracted through steam distillation and was chemically characterized using Gas Chromatography Mass Spectrometry (GC-MS). The antibacterial activity was assessed using microbroth dilution assay, metabolic viability assay and growth curve analysis. The mode of action was elucidated by the proteomics approach using Nano-LC-MS/MS followed by in silico analysis. The results of proteomic analysis were further validated through several in vitro assays. The cytotoxic nature of the essential oil was also confirmed using adenocarcinomic human alveolar basal epithelial (A549) cells. Furthermore, the safety and in vivo anti-infective efficacy of Plectranthus amboinicus essential oil was evaluated through survival assay, CFU assay and histopathological analysis of vital organs using zebrafish as a model organism. RESULTS: The chemical characterization of Plectranthus amboinicus essential oil revealed that it is predominantly composed of thymol. Thymol rich P. amboinicus essential oil demonstrated potent inhibitory effects on Klebsiella pneumoniae growth, achieving a significant reduction at a concentration of 400 µg/mL within 4 h of treatment The nano-LC-MS/MS approach unveiled that the essential oil exerted its impact by disrupting the antioxidant defense system and efflux pump system of the bacterium, resulting in elevated cellular oxidative stress and affect the biosynthesis of biofilm. The same was validated through several in vitro assays. Furthermore, the toxicity of Plectranthus amboinicus essential oil determined using A549 cells and zebrafish survival assay established a non-toxic concentration of 400 µg/mL and 12.5 µg/mL respectively. The results of anti-infective potential of the essential oil using Zebrafish as a model organism demonstrated significantly improved survival rates, reduced bacterial load, alleviated visible signs of inflammation and mitigated the adverse effects of infection on various organs, as evidenced by histopathological analysis ensuring its safety for potential therapeutic application. CONCLUSION: The executed in vitro and in vivo assays established the effectiveness of essential oil in inhibiting bacterial growth by targeting key proteins associated with the bacterial antioxidant defense system and disrupted the integrity of the cell membrane, highlighting its critical role in addressing the challenge posed by antibiotic-resistant Klebsiella pneumoniae.

Chemical Composition, Repellent, and Phytotoxic Potentials of the Fractionated Resin Essential Oil from Araucaria heterophylla Growing in Tunisia.

The resin essential oil (REO) of the Tunisian Araucaria heterophylla trunk bark was investigated for its chemical composition. Then, it was evaluated for its insecticidal and allelopathic activities. The REO was obtained by hydrodistillation for 9 h (yield of 4.2 % w/w). Moreover, fractional hydrodistillation was carried out at 3-hour intervals, resulting in 3 fractions (R1-R3), to facilitate chemical identification and localization of the aforementioned biological activities. GC/MS analysis of the obtained samples allowed the identification of 25 compounds, representing between 91.2 and 96.3 % of their total constituents, which consisted predominantly of sesquiterpene hydrocarbons, oxygenated sesquiterpenes and diterpene hydrocarbons. α-Copaene (10.8 %), γ-muurolene (5.8 %), α-copaen-11-ol (7.8 %), spathulenol (10.5 %), 15-copaenol (8.2 %), ylangenal (10.3 %), dehydrosaussurea lactone (7.7 %), and sandaracopimaradiene (11.4 %) were identified as major compounds. The second part aimed to assess the impact of the A. heterophylla EO and its three fractions for their insecticidal and repellent activity against Tribolium castaneum (Herbst), a stored grain pest, of which a strong repellent activity was noted. In addition, the studied samples showed high phytotoxic effects against Lactuca sativa. The third fraction (R3) performed a total inhibitory potential on seed germination and seedling growth of the target plant. Furthermore, alongside this discovery, an estimation was conducted through molecular docking analysis. Wherein the main compounds of the studied samples were docked into the active pocket of protoporphyrinogen IX oxidase (PDB: 1SEZ), a key enzyme in chlorophyll biosynthesis. Thus, it is recommended to use the REO of A. heterophylla as a natural herbicide.

Inhibitory Effects of Endemic Thyme's Thymol-Carvacrol Chemotype Essential Oil on Aspergillus Species with Free Radical Scavenging Properties.

There is a burgeoning focus on utilizing the antifungal and antioxidant properties of essential oils derived from various plants as a modern and natural approach to combat the growth of fungi that contaminate food. In this study, we used essential oils extracted from Thymus daenensis Celak. subsp. daenensis to address three mycotoxin-producing species of Aspergillus, specifically A. flavus, A. parasiticus, and A. niger, all of which are recognized contaminants of food and agricultural products. Concurrently, the antioxidant properties of the essential oils were evaluated, revealing their noteworthy role in the antifungal activity. Essential oils were derived from T. daenensis subsp. daenensis was observed to have a significant inhibitory effect on all three species of Aspergillus, as evidenced by the minimum inhibitory concentration (MIC) ranging from 575 to 707 ppm and the half-maximal inhibitory concentration (IC50) ranging from 237 to 280 ppm. These results confirm the strong antifungal activity of the essential oils. Furthermore, the essential oil exhibited free radical scavenging activity, resulting in an EC50 value of 37.1 µg/ml. In summary, T. daenensis subsp. daenensis essential oil demonstrated a competitive advantage over other similar plants and synthetic antibiotics. This indicates the promising potential of this essential oil as a natural antifungal agent to control Aspergillus growth and mycotoxin contamination. It offers an alternative or complementary approach to conventional antifungal agents and could be a valuable addition to the arsenal of natural remedies to address fungal contamination in food and agricultural products.

Chemical Profiling and Enzyme Inhibitory Activities of Essential Oil Isolated from Pistacia khinjuk Leaves: Insights On GC-MS Analysis and Skin Aging-Relevant Enzymes.

Pistacia khinjuk is a species of flowering plants belonging to family Anacardiaceae, with promising pharmacological activities like antioxidants, anti-inflammatory, antiviral, and antimicrobial. This study aimed to investigate the GC-MS chemical composition of essential oil isolated from Pistacia khinjuk leaves and its inhibitory properties against aging-relevant enzymes such a collagenase and elastase. The isolated oil showed predominance of ß-cadinene (15.34 %), γ-amorphene (8.50 %), α-cadinol (8.14 %), τ-cadinol (7.57 %), (E)-ß-caryophyllene (5.77 %), α-pinene (4.70 %), phytol (4.57 %), α-muurolene (3.30 %), (+)-epi-bicyclosesquiphellandrene (3.21 %), and cubenene (3.16 %). Further, it showed remarkable inhibitory activities against collagenase and elastase with IC50 values of 15.61±0.69 and 41.12±2.09 µg/mL, respectively compared to epigallocatechin gallate (IC50=29.52±1.3 µg/mL and 26.86±1.37 µg/mL). as a conclusion, the leaf oil is recommended for topical cosmetic preparations to retard skin aging symptoms such as wrinkles. However, the bioavailability assessment and toxicological profile should be considered in the future studies.

Antioxidant and Antimicrobial Activities of Chemically-Characterized Essential Oil from Artemisia aragonensis Lam. against Drug-Resistant Microbes.

This study investigated the chemical composition, antioxidant and antimicrobial activity of essential oil extracted from Artemisia aragonensis Lam. (EOA). Hydrodistillation was employed to extract EOA. Gas chromatography with flame ionization detection (GC-FID) and gas chromatography-mass spectrometry analyses (GC-MS) were used to determine the phytochemical composition of EOA. Antioxidant potential was examined in vitro by use of three tests: 2.2-diphenyl-1-picrilhidrazil (DPPH), ferric reducing activity power (FRAP) and total antioxidant capacity assay (TAC). Agar diffusion and microdilution bioassays were used to assess antimicrobial activity. GC/MS and GC-FID detected 34 constituents in the studied EOA. The major component was Camphor (24.97%) followed by Borneol (13.20%), 1,8 Cineol (10.88%), and Artemisia alcohol (10.20%). EOA exhibited significant antioxidant activity as measured by DPPH and FRAP assays, with IC50 and EC50 values of 0.034 ± 0.004 and 0.118 ± 0.008 mg/mL, respectively. EOA exhibited total antioxidant capacity of 7.299 ± 1.774 mg EAA/g. EOA exhibited potent antibacterial activity as judged by the low minimum inhibitory concentration (MIC) values against selected clinically-important pathogenic bacteria. MIC values of 6.568 ± 1.033, 5.971 ± 1.033, 7.164 ± 0.0 and 5.375 ± 0.0 µg/mL were observed against S. aureus, B. subtills, E. coli 97 and E. coli 57, respectively. EOA displayed significant antifungal activity against four strains of fungi: F. oxysporum, C. albicans, A. flavus and A. niger with values of 21.50 ± 0.43, 5.31 ± 0.10, 21.50 ± 0.46 and 5.30 ± 0.036 µg/mL, respectively. The results of the current study highlight the importance of EOA as an alternative source of natural antioxidant and antibacterial drugs to combat antibiotic-resistant microbes and free radicals implicated in the inflammatory responses accompanying microbial infection.

Anticancer activity of Zingiber ottensii essential oil and its nanoformulations.

Zingiber ottensii, is widely used in Asian traditional remedies for the treatment of many diseases. The present study explores anticancer activity of Z. ottensii essential oil (ZOEO) and its nanoformulations. ZOEO obtained from hydrodistillation of Z. ottensii fresh rhizomes was analysis using gas chromatography mass spectroscopy. Zerumbone (25.21%) was the major compound of ZOEO followed by sabinene (23.35%) and terpene-4-ol (15.97%). Four types of ZOEO loaded nanoformulations; nanoemulsion, microemulsion, nanoemulgels, and microemulgel, were developed. The average droplet size of the nanoemulsion and microemulsion was significantly smaller than that of the nanoemulgel and microemulgel. Comparison with other essential oils of plants of the same family on anticancer activity against A549, MCF-7, HeLa, and K562, ZOEO showed the highest cytotoxicity with IC50 of 43.37±6.69, 9.77±1.61, 23.25±7.73, and 60.49±9.41 µg/mL, respectively. Investigation using flow cytometry showed that ZOEO significantly increased the sub-G1 populations (cell death) in cell cycle analysis and induced cell apoptosis by apoptotic analysis. The developed nanoformulations significantly enhanced cytotoxicity of ZOEO, particularly against MCF-7 with the IC50 of 3.08±2.58, 0.74±0.45, 2.31±0.91, and 6.45±5.84 µg/mL, respectively. Among the four nanoformulations developed in the present study, nanoemulsion and microemulsion were superior to nanoemulgel and microemulgel in delivering ZOEO into cancer cells.

Essential oil from Lavandula angustifolia elicits expression of three SbWRKY transcription factors and defense-related genes against sorghum damping-off.

Sorghum damping-off, caused by Fusarium solani (Mart.) Sacc., is a serious disease which causes economic loss in sorghum production. In this study, antagonistic activity of lavender essential oil (EO) at 0.5, 0.75, 1.0, 1.25, 1.5, and 1.6% against F. solani was studied in vitro. Their effects on regulation of three SbWRKY transcription factors, the response factor JERF3 and eight defense-related genes, which mediate different signaling pathways, in sorghum were investigated. Effects of application under greenhouse conditions were also evaluated. The results showed that lavender EO possesses potent antifungal activity against F. solani. A complete inhibition in the fungal growth was recorded for lavender EO at 1.6%. Gas chromatography-mass spectrometric analysis revealed that EO antifungal activity is most likely attributed to linalyl anthranilate, α-terpineol, eucalyptol, α-Pinene, and limonene. Observations using transmission electron microscopy revealed many abnormalities in the ultrastructures of the fungal mycelium as a response to treating with lavender EO, indicating that multi-mechanisms contributed to their antagonistic behavior. Results obtained from Real-time PCR investigations demonstrated that the genes studied were overexpressed, to varying extents in response to lavender EO. However, SbWRKY1 was the highest differentially expressed gene followed by JERF3, which suggest they play primary role(s) in synchronously organizing the transcription-regulatory-networks enhancing the plant resistance. Under greenhouse conditions, treating of sorghum grains with lavender EO at 1.5% prior to infection significantly reduced disease severity. Moreover, the growth parameters evaluated, the activities of antioxidant enzymes, and total phenolic and flavonoid contents were all enhanced. In contrast, lipid peroxidation was highly reduced. Results obtained from this study support the possibility of using lavender EO for control of sorghum damping-off. However, field evaluation is highly needed prior to any usage recommendation.

Pink Lotus Essential Oil and Alleviates on Free Fatty Acid Induced Steatosis in HepG2 Cells via PI3K/Akt and NF-κB Pathways.

Pink lotus essential oil (PLEO) is the volatile components extracted from lotus flowers and there are few relevant research. The purpose of this study was to observe the effect of PLEO on NAFLD in vitro model and its possible mechanism. The ingredients of PLEO were determined by gas chromatography-mass spectrometry (GS-MS) and its lipid-lowering and hepatoprotective activities were investigated. HepG2 cells were treated with free fatty acid (FFA) to establish a cell model of NAFLD. Cell viability was evaluated by 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method. Total cholesterol (TC), triglyceride (TG), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6) were determined by Enzyme-Linked Immune Sorbent Assay (ELISA). Oil red O staining was performed to observe the lipid accumulation in the HepG2 cells. Lipid metabolism enzymes including fatty acid synthase (FAS), acetyl-coA carboxylase (ACC), stearoyl-CoA desaturase 1 (SCD-1), and carnitine palmitoyltransferase-1 (CPT-1), insulin signaling pathways including phosphatidylinositol 3 kinase (PI3K) and protein kinase B Akt, inflammatory signaling pathways such as nuclear factor kappa-B (NF-κB), were determined by Western blotting. There were 46 components determined in PLEO with many terpenoids compounds. PLEO decreased TC and TG contents in the FFA-treated HepG2 cells. Furthermore, PLEO inhibited TNF-α, IL-6 and IL-1ß excretion, decreased NF-κB, FAS, ACC and SCD-1 while increased phosphorylation of NF-κB, PI3K, Akt, and CPT-1 expression. It is the first time to reveal that PLEO alleviates FFA-induced steatosis in HepG2 cells by regulating lipid metabolism, inhibiting inflammatory response, and improving insulin sensitivity.

Chemical composition, enantiomeric analysis and anticholinesterase activity of Lepechinia betonicifolia essential oil from Ecuador.

CONTEXT: Due to the interesting potential of essential oils (EO) against cholinesterases and their close relation in Alzheimer's disease, the EO of Lepechinia betonicifolia (Lam) Epling (Lamiaceae), a native shrub from Ecuador, was assessed. Chemical profiling and enantiomeric distribution were also recorded for the first time. OBJECTIVE: To analyse the chemical profile including the enantiomeric composition and anticholinesterase effect exerted by EO of L. betonicifolia. MATERIALS AND METHODS: The EO of L. betonicifolia fresh aerial parts was obtained by hydrodistillation in a Clevenger-type apparatus. Physical properties were determined according to standard norms. The chemical composition was determined by GC-MS and GC-FID. Enantioselective GC-MS analysis was carried out by using a capillary chiral column. Anticholinesterase effect was assessed by Ellman's method with acetylthiocoline as substrate and Ellman's reagent (DTNB) to detect its hydrolysis at 405 nm for 60 min. Donepezil was used as a reference drug. EO was dissolved in methanol to reach 10 mg/mL concentration and two more 10× dilutions were included. RESULTS: Thirty-nine constituents were identified corresponding to 97.55% of the total oil composition. The main components were ß-pinene (30.45%), sabinene (27.98%), α-pinene (4.97%), ß-phellandrene (4.79%), E-caryophyllene (4.44%) and limonene (3.84%). L. betonicifolia EO exerted a strong inhibitory effect over the AChE enzyme with an IC50 value of 74.97 ± 1.17 µg/mL. DISCUSSION AND CONCLUSIONS: Current chemical characterisation and anticholinesterase effect of EO of L. betonicifolia encourage us to propose this EO as a candidate for the preparation of functional foods or as adjuvant therapy for Alzheimer's disease.

Radioprotective Effects of Plants from the Lamiaceae Family.

BACKGROUND: Edible and medicinal plants are still an interesting source of promising biologically active substances for drug discovery and development. At a time of increasing cancer incidence in the world, alleviating the bothersome side effects of radiotherapy in debilitated cancer patients is becoming an important challenge. OBJECTIVE: The aim of the study was to overview the literature data concerning the radioprotective activity of extracts, essential oils, and some chemical compounds obtained from 12 species belonging to the Lamiaceae family, gathering of numerous spice and medicinal plants rich in valuable phytochemicals. RESULTS: The analysis of available publications showed radioprotective effectiveness of essential oils and complex extracts containing phenolic acids and flavonoids in various in vitro and in vivo models. Relatively welldocumented preventive properties exhibited the following species: Mentha × piperita, Ocimum tenuiflorum, Origanum vulgare, and Rosmarinus officinalis. However, few plants such as Lavandula angustifolia, Mentha arvensis, M. spicata, Plectranthus amboinicus, Salvia miltiorrhiza, S. officinalis, Scutellaria baicalensis, and Zataria multiflora should be more investigated in the future. Among the mechanisms of radioprotective effects of well-studied extracts and phytochemicals, it can be mentioned mainly the protection against chromosomal damage, scavenging free radicals, decreasing of lipid peroxidation and elevating of glutathione, superoxide dismutase, catalase, and alkaline phosphatase enzyme levels as well as the reduction of the cell death. The plant substances protected the gastrointestinal tract, bone marrow and lung fibroblasts. CONCLUSION: The studied species of Lamiaceae family and their active chemical compounds are potent in alleviating the side effects of radiotherapy and should be considered as a complementary therapy.

Chemical and Bioactive Characterization of the Essential Oils Obtained from Three Mediterranean Plants.

Cupressus sempervirens L., Juniperus communis L. and Cistus ladanifer L. are Mediterranean arboreal and shrub species that possess essential oils (EO) in their leaves and branches. This study aimed at characterizing the EOs obtained by steam distillation from the three species collected in different locations from Spain (Almazán, Andévalo, Barriomartín, Cerezal, Ermitas and Huéscar). For this purpose, volatiles composition was determined by GC-MS, and different bioactivities were evaluated. The highest content in terpenes was observed in C. sempervirens (Huéscar origin) followed by J. communis (Almazán origin), corresponding to 92% and 91.9% of total compounds, respectively. With exception of C. ladanifer from Cerezal that presented viridiflorol as the most abundant compound, all the three species presented in common the α-pinene as the major compound. The EOs from C. ladanifer showed high antibacterial potential, presenting MIC values from 0.3 to 1.25 mg/mL. Concerning other bioactivities, C. ladanifer EO revealed an oxidation inhibition of 83%, while J. communis showed cytotoxicity in the MCF-7 cell line, and C. sempervirens and C. ladanifer EOs exhibited the highest potential on NCI-H460 cell lines. Nevertheless, some EOs revealed toxicity against non-tumoral cells but generally presented a GI50 value higher than that of the tumor cell lines.

Chemical Composition and Biological Screening of the Essential Oils of Micromeria macrosiphon and M. arganietorum (Lamiaceae).

The chemical composition and in vitro biological activities of the essential oil (EO) of Micromeria macrosiphon Coss. and M. arganietorum (J. Emb.) R. Morales, two Lamiaceae endemic to south Morocco, were investigated. GC/MS analysis resulted in the identification of 36 metabolites from the EO of M. macrosiphon, 45 from M. arganietorum. Borneol was the major metabolite in both oils and together with related derivatives such as camphor, accounted for 2/3 of the EO of M. macrosiphon, 1/3 of those of M. arganietorum. Pinene and terpinene derivatives were also present in high proportions. From a chemotaxonomic point of view, the composition of the examined samples may be related to those of other species endemic to Macaronesia. Both EOs showed significant toxicity towards liver HepG2 and melanoma B16 4A5 tumor cell lines at 100 µg/mL; however, they were also cytotoxic towards S17 normal cell lines, with a selectivity index <1. No antibacterial activity was noticed against 52 strains at 100 µg/mL.

Adaptogenic activity of Cinnamomum camphora, Eucalyptus globulus, Lavandula stœchas and Rosmarinus officinalis essential oil used in North-African folk medicine.

Depressive anxiety is one of the most emotional disorders in our industrial societies. Many treatments of phobias exist and are based on plant extracts therapies, which play an important role in the amelioration of the behavior. Our study aimed to evaluate the adaptogenic activity of different essential oils provided from local plants: Cinnamomum camphora (Camphora), Eucalyptus globulus (Blue gum), Lavandula stœchas (Topped lavender) and Rosmarinus officinalis (Rosemary) on Wistar rats. The adaptogenic activity was evaluated on the elevated plus-maze. The efficacy of the extract (200 mL/kg) was compared with the standard anxiolytic drug Diazepam® 1 mg. Animals administered by the essential oil of Lavandula stœchas, Cinnamomum camphora, Rosmarinus officinalis and Eucalyptus globulus showed a behavior similar to those treated with Diazepam®. For groups treated with the following essential oils: Rosmarinus officinalis, Lavandula stoechas and Cinnamomum camphora at a dose of 200 mL/kg, we notice an increase in the time spent on the open arms of the elevated plus-maze and a decrease in time spent on the closed arms of the elevated plus-maze, especially for Rosmarinus officinalis, which explains the anxiolytic effect of these plants. We also notice a decrease in the number of entries in closed arms, open arms and the number of passing to the central square. The increase in the number of entries to open arms with Eucalyptus globulus essential oil shows a reduction in anxiety behavior in rodents and this shows that these plants have an inhibitory effect.

Clove Essential Oil (Syzygium aromaticum L. Myrtaceae): Extraction, Chemical Composition, Food Applications, and Essential Bioactivity for Human Health.

Clove (Syzygium aromaticum L. Myrtaceae) is an aromatic plant widely cultivated in tropical and subtropical countries, rich in volatile compounds and antioxidants such as eugenol, ß-caryophyllene, and α-humulene. Clove essential oil has received considerable interest due to its wide application in the perfume, cosmetic, health, medical, flavoring, and food industries. Clove essential oil has biological activity relevant to human health, including antimicrobial, antioxidant, and insecticidal activity. The impacts of the extraction method (hydrodistillation, steam distillation, ultrasound-assisted extraction, microwave-assisted extraction, cold pressing, and supercritical fluid extraction) on the concentration of the main volatile compounds in clove essential oil and organic clove extracts are shown. Eugenol is the major compound, accounting for at least 50%. The remaining 10-40% consists of eugenyl acetate, ß-caryophyllene, and α-humulene. The main biological activities reported are summarized. Furthermore, the main applications in clove essential oil in the food industry are presented. This review presents new biological applications beneficial for human health, such as anti-inflammatory, analgesic, anesthetic, antinociceptive, and anticancer activity. This review aims to describe the effects of different methods of extracting clove essential oil on its chemical composition and food applications and the biological activities of interest to human health.

Nematicidal Activity of Essential Oil from Lavandin (Lavandula × intermedia Emeric ex Loisel.) as Related to Chemical Profile.

Essential oils (EOs) from lavandin are known for a large spectrum of biological properties but poorly and contrastingly documented for their activity against phytoparasitic nematodes. This study investigated the toxicity of EOs from three different lavandin cultivars, Abrialis, Rinaldi Cerioni, and Sumiens, either to juveniles (J2) and eggs of the root-knot nematode Meloidogyne incognita and to infective stages of the lesion nematode Pratylenchus vulnus. The suppressive activity of treatments with EOs from the three lavandin cultivars in soil infested by M. incognita was also investigated in a greenhouse experiment on potted tomato. The compositional profiles of tested EOs were also analyzed by GC-FID and GC-MS. Linalool was the major component of all the three EOs, as accounting for about 66%, 48%, and 40% of total EO from cv Rinaldi Cerioni, Sumiens, and Abrialis, respectively. Linalool acetate was the second most abundant compound in the EOs from cv Abrialis (18.3%) and Sumiens (14.9%), while significant amounts of camphor (11.5%) and 1,8-cineole (12.1%) were detected in cv Rinaldi Cerioni and Sumiens EOs, respectively. The mortality of M. incognita J2 peaked 82.0%, 95.8%, and 89.8% after a 24 h treatment with 100 mg·mL-1 solutions of cv Abrialis, Rinaldi Cerioni, and Sumiens EOs, respectively. Infective specimens of P. vulnus were largely more sensitive than M. incognita J2, as there were peak mortality rates of 65.5%, 67.7%, and 75.7% after 4 h of exposure to Abrialis, Rinaldi Cerioni, and Sumiens EO, respectively. All three lavandin EOs significantly affected also M. incognita egg hatchability, which reduced to 43.6% after a 48 h egg mass exposure to a 100 µg·mL-1 solution of cv Rinaldi Cerioni EO. Soil treatments with the three lavandin EOs strongly reduced, according to a dose-effect relationship, density of M. incognita eggs, and J2 both on tomato roots and in soil, as well as significantly reduced gall formation on tomato roots. Finally, almost all soil treatments with the lavandin EOs also resulted in a positive impact on tomato plant growth.

Antimicrobial Activity and Synergy Investigation of Hypericum scabrum Essential Oil with Antifungal Drugs.

The chemical composition of Lebanese Hypericum scabrum essential oil (EO) was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GG-MS). Its antimicrobial activity was evaluated by determining its minimal inhibitory concentrations (MICs) against a Gram-negative and a Gram-positive bacterium, one yeast, and five dermatophytes. H. scabrum EO was most active on filamentous fungi (MIC values of 32-64 µg/mL). Synergy within the oil was investigated by testing each of the following major components on Trichophyton rubrum: α-pinene, limonene, myrcene, ß-pinene and nonane, as well as a reconstructed EO. The antifungal activity of the natural oil could not be reached, meaning that its activity might be due, in part, to minor constituent(s). The interactions between H. scabrum EO and commercially available antifungals were assessed by the checkerboard test. A synergistic effect was revealed in the combination of the EO with amphotericin B.