Evaluation of the repellent effects of Nepeta parnassica extract, essential oil, and its major nepetalactone metabolite against mosquitoes.

The dichloromethane-methanol extract, the essential oil obtained by hydrodistillation from Nepeta parnassica, and the isolated 4aα,7α,7aß-nepetalactone were evaluated for their repellent effect against the mosquitoes Aedes (Stegomyia) cretinus Edwards and Culex pipiens pipiens biotype molestus Forskål. The chemical analysis of N. parnassica essential oil, dominated by oxygenated monoterpenes (87 %), revealed 4aα,7α,7aß-nepetalactone (36.8%), 1,8-cineole (25.5%), and 4aα,7ß,7aß-nepetalactone (11.1%) as the major constituents. The results of the insect bioassays showed that the essential oil and the dichloromethane-methanol extract of N. parnassica were very active against Aedes cretinus for up to 3 h and against Culex pipiens for up to 2 h post application. The isolated 4aα,7α,7aß-nepetalactone showed very high mosquito repellency for periods of at least 2 h against both species.

Protective effect of Calamintha officinalis Moench leaves against alcohol-induced gastric mucosa injury in rats. Macroscopic, histologic and phytochemical analysis.

Calamintha officinalis Moench (Lamiaceae) is an aromatic plant used since ancient times for its preservative and medicinal properties. The plant, known as 'Mentuccia' in Central Italy, is used in cooking as an aromatizant and to impart aroma and flavour to food. The methanol extract of the leaves was subjected to phytochemical and biological investigations. The extract contains polyphenols, catechic tannins and terpenes and shows radical scavenger activity. By means of HPLC analysis, eriocitrin, eriodyctiol, acacetin, linarin, benzoic acid and some phenolic acids, such as caffeic, chlorogenic, p-coumaric, were determined. The gastroprotective activity of the extract was investigated using ethanol-induced ulcer in rats, with sucralfate as a reference drug. Samples of gastric mucosa, stained by PAS and haematoxylin/eosin, were observed by light microscopy. The efficacy of the extract was comparable to that of the reference drug. Probably the gastroprotective effect depends on a synergistic action of all the compounds occurring in C. officinalis leaves, even if the antioxidant potential of the leaves plays an important role by removing damaging agents from the gastric mucosa.

Antiinflammatory and antioxidant activity of Hypericum rumeliacum Boiss. subsp. apollinis (Boiss. & Heldr.) Robson & Strid methanol extract.

Plants of the genus Hypericum are widely used in folk medicine for the treatment of gastric ailments (including pectic ulcers), burns, swelling, inflammation, anxiety, as well as for bacterial and viral infections. The aerial parts of Hypericum rumeliacum Boiss. subsp. apollinis (Boiss. & Heldr.) Robson & Strid (Guttiferae), a perennial herb growing wild in Greece, were subjected to biological and phytochemical studies. The H. rumeliacum methanol extract showed, on the DPPH test, antioxidant activity (IC(50) = 23.61 microg/mL). The antiinflammatory activity of the extract (70 mg/kg, i.p.), in the carrageenan-induced paw oedema in rat, was studied. In this experimental model an inhibition of paw oedema, significant from the first to third hour, was observed. The histological examination confirmed resolution of the inflammatory process observed in vivo. Through HPLC analysis of the H. rumeliacum methanol extract, the naphthodianthrones hypericin, pseudohypericin and some polyphenol compounds, such as chlorogenic acid, rutin and isoquercitrin, were identified and quantified. The antioxidant activity of H. rumeliacum could be chiefly related to polyphenol compounds that are well known as the main contributors to the free radical-scavenging effects. The antiinflammatory effect of the methanol extract of the aerial parts could be due to the synergic action both of hypericin and polyphenol compounds.

Chemical composition and in vitro antimicrobial activity of the essential oils of flower heads and leaves of Santolina rosmarinifolia L. from Romania.

The essential oils of the flower heads and leaves of Santolina rosmarinifolia L. (Compositae) cultivated in Romania were obtained through hydrodistillation and analysed by GC-MS. Forty-two components were identified, representing 92.3-94.0% of the whole composition of the samples. Their in vitro antimicrobial activity against gram-positive and gram-negative bacteria strains and the fungus Candida albicans was determined using the agar-diffusion method and the broth dilution method.

Ursolic acid plays a role in Nepeta sibthorpii Bentham CNS depressing effects.

The sedative, anticonvulsant and analgesic activity of ursolic acid, a terpenoid bioassay-isolated from Nepeta sibthorpii Bentham, was evaluated in mice. The oral administration of ursolic acid (2.3 mg/kg) produced a significant depressant effect on CNS by reducing spontaneous motor activity and the number and lethality of pentylenetetrazol (PTZ)-induced seizures. Two models of nociception, the writhing test and the hot plate test, were also used to examine the analgesic effect of ursolic acid. At a dose of 2.3 mg/kg, ursolic acid caused an inhibition of acetic acid-induced abdominal constriction, but was inactive in the hot plate test. Treatment at a higher dose (20 mg/kg) significantly increased the reaction time in the hot plate test. This effect, reversed by naloxone, evidently involves opioid receptors, but the analgesic activity of ursolic acid may be related also to the antiinflammatory and antioxidant properties of this compound.

Anti-inflammatory activity of extract and fractions from Nepeta sibthorpii Bentham.

Several species of Nepeta genus are utilized in folk medicine for treatment of contusions, rheumatic pains, fever, cutaneous eruptions. Some species are employed for their anti-inflammatory properties. In this paper, we report the results of phytochemical studies on aerial parts of Nepeta sibthorpii Bentham (Lamiaceae), an endemic plant of Greece. The bioassay-guided fractionation of methanol extract led to the isolation of ursolic acid and polyphenol fraction. By HPLC, we determined some phenolics: chlorogenic acid (0.315 mg/g) and the flavonoids rutin (0.091 mg/g), luteolin-7-O-glucoside (0.387 mg/g) and a luteolin derivative. We assayed the radical scavenging activity of Nepeta sibthorpii methanol extract by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. Moreover, we studied the anti-inflammatory activity of Nepeta sibthorpii methanol extract (50 mg/kg, os), ursolic acid and polyphenol fraction (dose corresponding to 50 mg/kg of methanol extract, os) in the carrageenan-induced paw oedema in rat. In this experimental model, we observed a significant inhibition of paw oedema. We suppose that the anti-inflammatory effect of methanol extract could be related to the free radical scavenging activity and that it depends on a synergic action of all the components of the methanol extract, even if ursolic acid can be considered the main responsible for this activity.

Chemical analysis and antifungal activity of Thymus striatus.

The essential oil composition from Thymus striatus collected from Mountain Orjen (Montenegro) has been investigated by gas chromatography-mass spectrometry. Thymol, gamma-terpinene and p-cymene were found to be the major components. Furthermore, the oil and its major component, thymol, were analysed for potential antifungal activity against plant, animal and human pathogenic fungi from different genera by a macrodilution test. The oil exhibited a strong inhibitory effect against all fungi investigated.

Cytotoxic activities of some Greek Labiatae herbs.

Nineteen methanolic crude plant extracts of Labiatae family, collected in Greece from different locations, were evaluated for cytotoxic activity against brine shrimps and three human cancer cell lines along with a normal mouse cells as a control cell line. In the brine shrimp lethality test, Mentha pulegium was the only sample found to be active with an LC(50) value 347.3 micro g/ml, while all remaining samples had LC(50) values greater than 1000 micro g/ml. In case of Caco-2 and HepG2 cell lines, only one sample, namely Thymus parnassicus Halacsy, was active with LC(50) values 44.6 and 50.3 micro g/ml respectively, while against MCF-7 cell line, two samples, namely, Clinopodium vulgare L. (LC(50): 60.4 micro g/ml), and Thymus parnassicus Halacsy (LC(50): 54.7 micro g/ml), were found active.

Composition and antimicrobial activity of the essential oil of Hypericum rumeliacum subsp. apollinis (Boiss. & Heldr.).

The composition and the antimicrobial activity of the aerial parts of Hypericum rumeliacum are reported. Analysis was carried out by GC/MS. The major constituents were alpha-pinene (43.80%), beta-pinene (9.82%), dehydro-aromadendrene (6.81%) and alpha-copaene (5.41%). The essential oil showed a moderate in vitro activity against the six Gram negative and positive bacteria and a stronger one against the three-tested pathogenic activity.

Composition and antimicrobial activity of the essential oil of Ballota pseudodictamnus L. Bentham.

The chemical composition of the essential oil of Ballota pseudodictamnus obtained from the aerial parts was analysed by GC/MS. From the 52 identified constituents of the oil, caryophyllene oxide, phytol and gamma-muurolene were the major components. Furthermore, the essential oil was investigated for its antimicrobial activity.

Antifungal activities of selected aromatic plants growing wild in Greece.

Essential oils of Origanum onites, Satureja thymbra, Salvia fruticosa (Greek sage), and Salvia pomifera subsp. calycina plants growing wild in Greece and their components carvacrol, camphor, and 1,8-cineole, were assayed for antifungal activity against 13 fungal species. Among the fungi tested were food poisoning, plant, animals and human pathogenic species. The oils presented various degrees of inhibition against all the fungi investigated. The highest and broadest activity was shown by the carvacrol content oils (O. onites and S. thymbra), while the oil of sage was the least effective. Carvacrol exhibited the highest and 1,8-cineole the lowest level of antifungal activity among the components tested.

Nepeta sibthorpii Bentham (Lamiaceae): micromorphological analysis of leaves and flowers.

Nepeta sibthorpii Bentham (Lamiaceae) is an herbaceous aromatic plant, growing in dry, usually rocky areas of Southern Greece. In this paper, we report the study of micromorphological features of the flowers and leaves of Nepeta sibthorpii Bentham. The analysis by means of scanning electron microscopy has permitted to characterize both the covering trichomatous garment, abundantly present on the calyx and on the leaves, and the glandular hairs, distributed on the adaxial leaf surface and on the outer surfaces of calyx and corolla, showing also the peculiar features of the epidermal cells, all useful diagnostic elements for the identification of this medicinal plant.

Anti-inflammatory and analgesic activity of Hypericum empetrifolium Willd. (Guttiferae).

A methanolic extract of Hypericum empetrifolium Willd. was evaluated for anti-inflammatory properties in rats (subplantar edema induced by carrageenan) and analgesic effects in mice (hot plate and writhing tests). Our results showed that the methanolic extract exhibits a significant anti-inflammatory activity and analgesic effects only in one of the experimental models (writhing test). Therefore, we may suppose that the methanolic extract of H. empetrifolium is active against inflammatory pain.

Composition and antimicrobial activity of the essential oil of Salvia ringens.

The essential oils of Salvia ringens (samples A and B), were analyzed by means of GC and GC/MS. From the seventy-five identified constituents representing 99.82 and 99.86% of the oils, 1,8-cineole and alpha-pinene were the major components. Furthermore, sample B exhibited a very interesting antimicrobial profile after it was tested against six gram (+/-) bacteria and three pathogenic fungi.

Essential oil of Phlomis lanata growing in Greece: chemical composition and antimicrobial activity.

The essential oil obtained from the aerial parts of Phlomis lanata has been analyzed by GC/MS. 48 compounds representing 96.85% of the oil were identified; alpha-pinene, limonene and trans-caryophyllene were found as its main components. The essential all showed a moderate in vitro activity against six Gram (+/-) bacteria and a stronger one against the three tested pathogenic fungi.

Effects of Teucrium divaricatum Heldr. ssp. divaricatum decoction on experimental ulcer in rats.

The effects of chronic intragastric administration of the aerial parts decoction of Teucrium divaricatum Heldr. ssp. divaricatum (Labiateae) on experimental acetylsalicylic acid (ASA)-induced ulcer were studied in rats. The ulcer index and histological mucosa regeneration were evaluated. The ulcer index significantly decreased (U.I. 1.7+/-1.5; P<0.05) after treatment with a lyophilized decoction of T. divaricatum (500 mg/kg os), once daily for 7 days, compared to the control (U.I. 11.4+/-2.3). The ultrastructure modifications of gastric mucosa were observed by transmission electronic microscopy (TEM) confirming the antisecretory effect exercised by administration of the T. divaricatum decoction. Treatment with T. divaricatum seems to block up parietal cell acid secretion and to stimulate in the chief cells the formation of zymogen granules.

Chemical and antibacterial studies of two Helichrysum species of Greek origin.

The chemical composition of the essential oils obtained from the aerial parts of Helichrysum stoechas ssp. barrelieri and H. taenari was analysed by GC and GC/MS. From the thirty-nine identified constituents representing the 73.87% and 87.41% of the two oils, respectively, beta-elemene, beta-caryophyllene, geraniol, and camphene were the major components. Furthermore, it was found that the oils exhibited significant antibacterial activity against six Gram (+/-) bacteria.