In vitro antimicrobial activity of the leaf extract of Harungana madagascariensis Lam. Ex Poir. (Hypericaceae) against strains causing otitis externa in dogs and cats.

Otitis externa in dogs and cats is always caused by a combination of yeasts and bacteria, among which the most important are Malassezia pachydermatis, Staphylococcus intermedius and Pseudomonas species. These organisms often develop resistance to classical antimicrobial agents. Therefore, the aim of this study was to investigate the antimicrobial activities of an ethyl acetate leaf extract of Harungana madagascariensis against the organisms cited, to carry out the phytochemical investigation of this extract and to determine its bioactive chemical class using dilution techniques, the bioautography method and the standard phytochemical method described by Harborne (1973). Phytochemical analysis revealed the presence of saponins, tannins, flavonoids, alkaloids and anthracenic derivatives. The bioassay showed that the antimicrobial properties may be attributed to astilbin, a flavanone derivative identified on the basis of its spectroscopic data. The results suggest that the extract could be used in an antimicrobial preparation effective against the whole range of organisms incriminated in otitis externa in dogs and cats, with a minimal inhibitory concentration (MIC) of 250 microg/ml.

Chemical composition and in vitro antifungal and antioxidant activity of the essential oil and methanolic extract of Teucrium sauvagei Le Houerou.

The chemical composition and the in vitro antifungal and antioxidant activity of the essential oil and the methanolic leaf extracts of Teucrium sauvagei Le Houerou, an endemic medicinal plant growing in Tunisia, have been studied. More than 35 constituents having an abundance >or=0.2% were identified in the oil. beta-Eudesmol, T-cadinol, alpha-thujene, gamma-cadinene, and sabinene were the prevalent constituents. Results of the antifungal activity tests indicated that the methanolic extract inhibited the in vitro growth of seven dermatophytes, whereas the essential oil showed average inhibition against only three dermatophytes. In vitro antioxidant properties of the essential oil and the methanolic extract were determined by DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid)) assays and compared to those of the synthetic antioxidant Trolox. Due to their antifungal and antioxidant properties, the essential oil and the methanolic extract of T. sauvagei may be of use as natural preservative ingredients in food and/or pharmaceutical industries.

Isolation and in vitro antibacterial activity of astilbin, the bioactive flavanone from the leaves of Harungana madagascariensis Lam. ex Poir. (Hypericaceae).

Harungana madagascariensis is well known for its topical antibacterial properties used in the elaboration of a lot of skin hygiene products. The aim of this study was, on the one hand, to evaluate the in vitro antibacterial activities of aqueous, ethanolic and ethyl acetate crude extracts of Harungana madagascariensis leaves against bacterial strains representative of skin microflora and, on the other hand, to determine the chemical structure of the active compound. Only the ethyl acetate leaf extract presented important antibacterial activity. Its fractionation was carried out by column chromatography using silica gel 60 and it yielded 11 fractions. A bioautographic method, revealed in these fractions the presence of a flavanone as the active compound astilbin or 3-O-alpha-L-rhamnoside-5,7,3',4'-tetrahydroxydihydroflavonol which was identified on the basis of its spectroscopic data. Concerning the antibacterial activity against the representative skin microflora of the armpit and feet, MIC and MBC ranged from 25 to 250 and 100 to 750 microg ml-1, respectively. The results showed that some bacteria considered to be responsible for bad odours at the armpit and feet levels, were destroyed at 200 microg ml-1 (MBC), a concentration sparing most of the useful saprophytic microflora. The minimal inhibitory quantity (MIQs) of astilbin ranged from 50 to 100 microg.

[Study on the inhibitory activity, in vitro, of baicalein and baicalin against skin fungi and bacteria].

In this paper, we concentrated in examining, in vitro, the antiseptic activity of the baicalein and baicalin upon the seventeen pathogenic skin fungal and sixteen skin bacterial strains, these two flavonic compounds were known principally as the biosubstances of a traditional Chinese medicinal plant: Scutellaria baicalensis. In agar media, the baicalein possessed potent specific activity against the pathogenic yeasts with MICs of 70-100 micrograms/ml; But in the same condition, no inhibitory effect was observed upon dermatophytes and filamentous imperfect fungi for baicalein, and upon all used strains for baicalin. According to the antibacterial test of baicalein, a high efficacy was achieved against certain causative specie of axillary and foot's odour such as Micrococcus sedentarius, Staphylococcus epidermidis, S. hominis and C. xerosis with a MICs inferior to 250 micrograms/ml. The good inhibitory activity of baicalein could be linked to the group hydroxyl (-OH) in position seven of the molecule.

Antifungal properties of Ocimum gratissimum essential oil (ethyl cinnamate chemotype).

Largely widespread in tropical countries, Ocimum gratissimum has been claimed for many uses in folk medicine. Recent research on its essential oils showed five chemotypes. An Indian chemotype, with a high level of ethyl cinnamate, presents, in vitro, an interesting spectrum of antifungal properties.

Distribution of the amatoxins and phallotoxins in Amanita phalloides. Influence of the tissues and the collection site.

The toxin composition of 25 Amanita phalloides carpophores collected from three sites in Franche-Comté (France) differing in their geological and pedological characteristics was determined and the factors involved in the variations of the toxin concentration in the tissues were identified. The concentrations of the main amatoxins (beta-amanitin, alpha-amanitin, gamma-amanitin) and phallotoxins (phallacidin, phallisacin, phalloidin, phallisin, phalloin) in the six tissues constituting the carpophore, i.e. the cap (C), gills (G), ring (R), stipe (S), bulb (B) and volva (V) were evaluated by using high-performance liquid chromatography. The results analysed statistically showed that the toxin concentrations were tissue dependent, leading to classification of the tissues into two groups (B, V) and (C, G, R, S). The (B, V) group was distinguished by high amounts of phalloidin, phallisin and phallisacin, and the (C, G, R, S) group by the predominance of the amatoxins. The characteristics of the soil of the collection site also affected the toxin concentrations; however, this effect differed from one site to another and was not similar for all the tissues. Finally, the mean toxin profile in the carpophores from the three sites was evaluated. This study underscores the fact that environmental factors and mainly the soil type clearly have an effect on the toxin composition of A. phalloides carpophores.

Use of caryophyllene oxide as an antifungal agent in an in vitro experimental model of onychomycosis.

Caryophyllene oxide, an oxygenated terpenoid, well known as preservative in food, drugs and cosmetics, has been tested in vitro as an antifungal against dermatophytes. Its antifungal activity has been compared to ciclopiroxolamine and sulconazole, commonly used in onychomycosis treatment and chosen because of their very different chemical structures. So, a new model has been tested, utilizing sheep hoof plates in order to simulate human nails, which are almost unobtainable for in vitro tests. Three protocols were utilized: pre-treatment, simultaneous treatment and post-treatment. Among these, the post-treatment method was the best to simulate antifungal therapy, as it permitted testing and comparing the efficiency of different antifungal drugs.

[Old plants and medicines used by Anabaptists-Mennonits in the days of old]. / Plantes et remedes d'utilisation ancienne par les Anabaptistes-Mennonites.

The evangelic Christian Mennonits, issued from Helvetia, spread first in Alsace, then in the neighbouring countries, bringing so traditions in agronomy and folk medicine. As generally in rural areas, in the days of old, natural therapies were characterised by rather strange practices, sometimes imbued with superstitions and mystic ideas. Some works, books, almanacs, dweller manuscripts, allow us to reach some uses forsaken and replaced by modern and scientific medicines.

[Antiseptic properties of essential oil of Lippia sidoides Cham. Application to the cutaneous microflora]. / Les propriétés antiseptiques de l'huile essentielle de Lippia sidoides Cham. Application à la microflore cutanée.

Two samples of essential oils of Lippia sidoides Cham. have been tested for their antibacterial and antifungal properties against some microorganisms living on the skin of feet and armpits. The essential oils and also their main components, thymol and carvacrol, show strong antagonistic activities. Corynebacterium xerosis developing axillary odour is specially inhibited. But on the other hand no specific activities have been observed upon the feet microflora.

[Antifungal activity in vitro of Scutellaria baicalensis Georgi upon cutaneous and ungual pathogenic fungi]. / Activité antifongique in vitro de Scutellaria baicalensis Georgi vis-à-vis de champignons pathogènes cutanés et unguéaux.

The root of Scutellaria baicalensis Georgi (Lamiaceae) is one of the traditional drugs commonly used in the Far East. The extracts obtained by the successive exhaustion in chloroform and in ethyl acetat present clear fungistatic activities in vitro against to some cutaneous and ungual pathogenic fungi, and particularly upon strains of Candida albicans, Cryptococcus neoformans and Pityrosporum ovale. For each of these, its minimum inhibitory concentration is determined. The ethyl acetat extract appears the most interesting because of its efficiency and of its stability. An antifungal substance is found out as the baicalein.

Antifungal properties of essential oils and their main components upon Cryptococcus neoformans.

Cryptococcus neoformans opportunistic fungus met in the last phasis of AIDS is inhibited in vitro by several essential oils on natural volatile compounds. The minimal inhibitory concentration may reach 100 microliters/l and minimal fungicidal concentration 200 microliters/l with Palmarosa or Cinnamon oils. Among phenolic compounds, thymol and carvacrol are most fungitoxic. Terpenoids, citral, geraniol, and citronellol show best activities.

[Campaign against allergenic moulds in dwellings. Inhibitor properties of essential oil of Geranium 'Bourbon', citronellol, geraniol and citral]. / Lutte contre les moisissures allergisantes des habitations. Propriétés inhibitrices de l'huile essentielle de Géranium 'Bourbon', du citronellol, du géraniol et du citral.

Many fungal airborne spora show allergenic effects. Indoor (dwelling, work rooms, hospital chambers) can be disinfected by elimination of living particles. We have undertaken experiments in more and more spacious bulks for evaluation of the antifungal effects of vapours of essential oils and some volatiles compounds. Results show that the Mucorales and Geotrichum resist strongly. On the contrary, the Cladosporium strains, some Aspergillus and Penicillium, Trichothecium roseum are the most sensitive, specially towards the citral vapours. Experiments in hospital can be undertaken.

[Fungal spores in the atmosphere at Besançon, France: seasonal and annual variations during 1988 and 1989]. / Les spores fungiques dans l'atmosphère de Besançon, France: variations saisonnières et annuelles au cours des années 1988 et 1989.

Airborne spora in the atmosphere of Besançon were weekly determined, searching links between appearance of species and seasonal allergies. By comparison of the results of the two years, it is easy to see many variations. At first, the number of colonies collected is very different, 2,990 colonies in 1988, 9,841 in 1989. During 1989, some genera are present in greatest quantities. It is the case of Cladosporium and Epicoccum in summer and Aspergillus in autumn. For the allergologists, Alternaria, very abundant during 1989, is perhaps the outstanding incident, this genus being considerated as very allergenic.

[Antifungal effects in vitro of jasmon and some similar compounds. Structure-activity relationship]. / Effects antifongiques in vitro de la jasmone et de quelques composés voisins. Relation structure-activité.

The antimycotic activity in vitro of jasmon and 6 closely related substances has been tested against four different dermatophytes, Candida albicans, Pityrosporum ovale and Aspergillus fumigatus. Jasmon had the highest activity. Among the other substances tested only thiazolidines with a carbonyl function developed antifungal properties against dermatophytes. 2,4 thiazolidinedione at 450 ppm inhibits the growth of Trichophyton rubrum.