Toxicological and pharmacological properties of essential oils of Calamintha nepeta, Origanum virens and Thymus mastichina of Alentejo (Portugal).

Three autochthonous flavouring herbs from Alentejo (Portugal), Calamintha nepeta (syn. Clinopodium nepeta), Origanun virens and Thymus mastichina, were selected to evaluate toxicological, antioxidant, antiproliferative and antimicrobial potential of their essential oils (EOs). C. nepeta and T. mastichina EOs showed a high content of oxygenated monoterpenes (86-91%) while O. virens had similar content of oxygenated and hydrocarbon monoterpenes (45%). Toxicological assessment suggests high activity against A. salina (31.8 < CL50 < 128.4 mg/L) and very low toxicity in Swiss mice (DL50 ≥ 1500 mg/kg). EOs showed high antioxidant ability by DPPH radical scavenging assay (0.1-0.6 mg QE/mL EO), total reducing power method (0.2-1.7 mg QE/mL EO) and ß-carotene/linoleic acid system (11-501 mg QE/mL EO). An important antiproliferative effect against human breast tumour cell line was observed (88.9 < EC50 < 108.5 mg/L). Moreover, EOs presented a large antibacterial spectrum. Results point out the low toxicity and high antioxidant, antiproliferative and antimicrobial activities of EOs of these endemic aromatic plants, suggesting their potential use in biotechnological, food and/or pharmaceutical industries.

Chemical Composition, Antibacterial, Antibiofilm and Synergistic Properties of Essential Oils from Eucalyptus globulus Labill. and Seven Mediterranean Aromatic Plants.

Essential oils (EOs) from Eucalyptus globulus Labill. ssp. globulus and from Mediterranean autochthonous aromatic plants - Thymus mastichina L., Mentha pulegium L., Rosmarinus officinalis L., Calamintha nepeta (L.) Savi ssp. nepeta, Cistus ladanifer L., Foeniculum vulgare L., Dittrichia viscosa (L.) Greuter ssp. viscosa - were extracted by hydrodistillation and characterized by GC-FID and NMR spectroscopy. EOs were evaluated for antimicrobial properties against several bacterial strains, using diverse methods, namely, the agar disc-diffusion method, the microdilution method, the crystal violet assay and the Live/Dead staining for assessment of biofilm formation. Potential synergy was assessed by a checkerboard method. EOs of R. officinalis and C. ladanifer showed a predominance in monoterpene hydrocarbons (> 60%); EOs of C. nepeta, M. pulegium, T. mastichina, E. globulus and F. vulgare were rich in oxygenated monoterpenes (62 - 96%) whereas EO of D. viscosa was mainly composed of oxygenated sesquiterpenes (54%). All EOs showed antimicrobial activity; M. pulegium and E. globulus generally had the strongest antimicrobial activity. EO of C. nepeta was the most promising in hampering the biofilm formation. The combinations D. viscosa/C. nepeta and E. globulus/T. mastichina were synergistic against Staphylococcus aureus. These results support the notion that EOs from the aromatic plants herein reported should be further explored as potential pharmaceuticals and/or food preservatives.

Antioxidant activity and cholinesterase inhibition studies of four flavouring herbs from Alentejo.

Essential oils (EOs) and aqueous extracts of aerial parts of four aromatic species, Calamintha nepeta, Foeniculum vulgare, Mentha spicata and Thymus mastichina, from southwest of Portugal were characterised chemically and analysed in order to evaluate their antioxidant potential and cholinesterase inhibitory activities. The main components of EOs were oxygenated monoterpenes, and aqueous extracts were rich in phenol and flavonoid compounds. EOs and aqueous extracts presented a high antioxidant potential, with ability to protect the lipid substrate, free radical scavenging and iron reducing power. Furthermore, EOs and extracts showed AChE and BChE inhibitory activities higher than rivastigmine, the standard drug. Results suggested the potential use of EOs and aqueous extracts of these flavouring herbs as nutraceutical or pharmaceutical preparations to minimise the oxidative stress and the progression of degenerative diseases.

New cholinesterase inhibitors for Alzheimer's disease: Structure Activity Studies (SARs) and molecular docking of isoquinolone and azepanone derivatives.

A library of isoquinolinone and azepanone derivatives were screened for both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity. The strategy adopted included (a) in vitro biological assays, against eel AChE (EeAChE) and equine serum BuChE (EqBuChE) in order to determine the compounds IC50 and their dose-response activity, consolidated by (b) molecular docking studies to evaluate the docking poses and interatomic interactions in the case of the hit compounds, validated by STD-NMR studies. Compound (1f) was identified as one of these hits with an IC50 of 89.5µM for EeAChE and 153.8µM for EqBuChE, (2a) was identified as a second hit with an IC50 of 108.4µM (EeAChE) and 277.8µM (EqBuChE). In order to gain insights into the binding mode and principle active site interactions of these molecules, (R)-(1f) along with 3 other analogues (also as the R-enantiomer) were docked into both RhAChE and hBuChE models. Galantamine was used as the benchmark. The docking study was validated by performing an STD-NMR study of (1f) with EeAChE using galantamine as the benchmark.

Pharmacological and Toxicological Studies of Essential Oil of Lavandula stoechas subsp. luisieri.

The present study was carried out to evaluate the chemical and pharmacological properties of the essential oil of Lavandula stoechas subsp. luisieri, which is a spontaneous shrub widespread in Alentejo (Portugal). Oxygenated monoterpenes, such as 1,8-cineole, lavandulol, and necrodane derivatives, are the main components of essential oil. It revealed important antioxidant activity with a high ability to inhibit lipid peroxidation and showed an outstanding effect against a wide spectrum of microorganisms, such as gram-positive and gram-negative bacteria and pathogenic yeasts. The analgesic effect studied in rats was dose dependent, reaching a maximum of 67 % at 60 min with the dose of 200 mg/kg and the anti-inflammatory activity with this dose caused an inhibition in carrageenan-induced rat paw oedema (83 %) that is higher than dexamethasone 1 mg/Kg (69 %). Besides, animals exhibited normal behaviour after essential oil administration, revealing low toxicity. The essential oil of L. luisieri from Alentejo presents important pharmacological properties and low toxicity, and is a promised candidate to be used as a food supplement or in pharmaceutical applications.

Antimicrobial activity and chemical composition of the essential oils of Portuguese Foeniculum vulgare fruits.

The aim of this study was to investigate the chemical composition and antimicrobial activity of essential oils obtained by hydrodistillation from fruits of six fennel accessions collected from wild populations occurring in the centre and south of Portugal. Composition of essential oils was established by Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography-Mass Spectrometry (GC-MS) analysis. The obtained yields of the essential oils were found to vary greatly in the range of 1.1 to 2.9% (v/w) and the chemical composition varied with the region of collection. A total of 16 compounds were identified. The main compounds were fenchone (16.9 - 34.7%), estragole (2.5 - 66.0%) and trans-anethole (7.9 - 77.7%). The percentages of these three main compounds were used to determine the relationship between the different oil samples and to group them into four different chemotypes: anethole/fenchone; anethole; estragole and anethole/estragole. Antifungal activity of essential oils was evaluated against six food spoilage fungi: Aspergillus niger, A. japonicus, A. oryzae, Fusarium oxysporum, Rhizophus oryzae and R. stolonifer. Antibacterial activity was assessed against three Gram-positive strains: Enterococcus faecalis ATCC 29212, Staphylococcus epidermidis ATCC 12228 and S. aureus ATCC 28213; and against six Gram-negative strains: Escherichia coli ATCC 25922; Morganella morganii LFG 08; Proteus mirabilis LFG 04; Salmonella enteritidis LFG 05; S. entiritidis serovar typhimurium LFG 06 and Pseudomonas aeruginosa ATCC 27853 by the disc diffusion agar method; the minimal inhibitory concentration (MIC) was determined using the broth macro-dilution method. The MIC values varied from 62.5 (E. coli ATCC 25922) to 2000 µmL (P. aeruginosa ATCC 27853).

Antioxidant, antimicrobial and toxicological properties of Schinus molle L. essential oils.

ETHNOPHARMACOLOGICAL RELEVANCE: Schinus molle L. has been used in folk medicine as antibacterial, antiviral, topical antiseptic, antifungal, antioxidant, anti-inflammatory, anti-tumoural as well as antispasmodic and analgesic; however, there are few studies of pharmacological and toxicological properties of Schinus molle essential oils. The aim of this study was to evaluate the antioxidant and antimicrobial activities of Schinus molle leaf and fruit essential oils, correlated with their chemical composition and evaluate their acute toxicity. MATERIALS AND METHODS: The chemical composition of Schinus molle leaf and fruit essential oils were evaluated by GC-FID and GC-MS. Antioxidant properties were determined using the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) free radical and ß-carotene/linoleic acid methods. Antimicrobial properties were evaluated by the agar disc diffusion method and minimal inhibitory concentration assay. Toxicity in Artemia salina and acute toxicity with behavioural screening in mice were evaluated. RESULTS: The dominant compounds found in leaf and fruit essential oils (EOs) were monoterpene hydrocarbons, namely α-phellandrene, ß-phellandrene, ß-myrcene, limonene and α-pinene. EOs showed low scavenging antioxidant activity by the DPPH free radical method and a higher activity by the ß-carotene/linoleic acid method. Antimicrobial activity of EOs was observed for Gram+, Gram- pathogenic bacteria and food spoilage fungi. EOs showed totoxicity for Artemia salina and lower toxicity in Swiss mice. CONCLUSIONS: The result showed that EOs of leaves and fruits of Schinus molle demonstrated antioxidant and antimicrobial properties, suggesting their potential use in food or pharmaceutical industries.

Estudo sobre eventual influencia do estimulo para producao de macrofagos, por meio da proteose-peptona, na infeccao experimental de camundongos pelo Plasmodium berghei / Study about eventual influence of macrophage stimulation by means of proteose-peptone in experimental infection caused by Plasmodium berghei in mice

A disponibilidade de modelo experimental, baseado na infeccao de camundongos pelo Plasmodium berghei, permitiu a realizacao do presente estudo, no qual procurou-se verificar possivel diminuicao da parasitemia e consequente alteracao quanto a mortalidade como decorrencia de exacerbacao macrofagica inespecifica, apos estimulo por meio de proteose-peptona a 10 por cento. Os resultados nao demonstraram a cogitada acao sobre os protozoarios, mantendo-se o nivel de parasitemia e a mortalidade proximos ao verificado no grupo de animais infectados, sem participacao do indutor da producao de macrofagos. Assim, pelo menos de acordo com a metodologia empregada, nao ocorreu a contencao da protozoose, sugerida por informacoes registradas em publicacoes anteriores.

Seleçäo de doadores de sangue: divergências de resultados de provas sorológicas para diagnóstico da doença de chagas / Blood donors selection: results divergences of sorologics tests for Chagas desease diagnosis

Resultados de provas sorológicas para diagnóstico da doença de Chagas, interpretados como duvidosos ou inconclusivos e decorrentes de execuçoes em Serviço de Hemoterapia, mereceram avaliaçao por meio de repetiçoes, associadas a análises parasitológicas. Claras discordâncias foram verificadas, indicando que a triagem de doadores de sangue nem sempre é confiável, afigurando-se necessário que se torne mais segura, a fim de evitar impropriedades vigentes.