Gentiana Species

Distribution and Importance Gentiana species belong to the family Gentianaceae, order Gentianales, superorder Gentiananae, subclass Asteridae, class Magnoliopsida (). The species are divided into several sections according to the morphology of the above-ground organs (). The subgenera Eugentiana Kusnezow and Gentianella Kusnezow () are entered in Flora Europaea as separate genera: Gentiana L. and Gentianella Moench (). The genus Gentiana comprises about 400 species distributed chiefly in mountain regions, especially in the Alps, the Carpathians, the Central Asia mountains, and the Andes in South America. Due to their impressive and colorful flowers, gentians decorate mountain meadows. Some species are also found in the monsoon zone of India, in New Zealand, and in southern Australia. More rarely, gentians are found in the temperate zone lowlands of the northern hemisphere (). The yellow gentian root was already mentioned as a remedium stomachicum by Galen and Dioscorides (). Apart from Gentiana Iutea L., there are other medicinal species included in many pharmacopoeias and plant registers of the world (). According to most European pharmacopoeias, the official drug may also contain material from Gentiana pannonica Read more […]

Antimicrobial activity of eucalyptus oils

The preservative properties of the volatile oils and extracts of aromatic and medicinal plants have been recognised since Biblical times, while attempts to characterise these properties in the laboratory date back to the early 1900s (e.g. Hoffman and Evans 1911). Martindale (1910) included ‘Eucalyptus amygdalina’ (probably the phellandrene variant of Eucalyptus dives) and Eucalyptus globulus oils, as well as eucalyptol (1,8-cineole), in his study of the antiseptic powers of essential oils and although the ‘carbolic coefficients’ of eucalyptus oils were not as great as those for oils containing large amounts of phenolics – such as origanum (carvacrol), cinnamon leaf (eugenol) and thyme (thymol) – they did, nevertheless, give some quantitative measure of the antiseptic properties of eucalyptus leaf oils. Many volatile oils – particularly those of herbs and spices, but including those from Eucalyptus – have been used to extend the shelf-life of foods, beverages and pharmaceutical and cosmetic products; their antimicrobial and antioxidant properties have also pointed to a role in plant protection. Such a wide variety of applications, actual or potential, has meant that the antimicrobial properties of Read more […]

Pharmacological Effects of Thyme

Antimicrobial effects of thyme essential oils and thyme preparations Antibacterial effects The first researcher who attributed antibacterial properties to thyme (without specifying the species) was Chamberlain in 1887, after observing the antibacterial effect of its “vapours” on Bacillus anthracis. Since then, numerous studies with essential oils of different species of Thymus have been carried out. They were shown to inhibit a broad spectrum of bacteria, generally Gram-positive bacteria being more sensitive than Gram-negative bacteria. This became obvious in some screening studies administering Thymus oils to a variety of bacteria. Recently the antibacterial activity of thyme (Thymus vulgaris) oil against some important food-borne pathogens, namely Salmonella enteritidis, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, and Campylobacter jejuni, was tested. The latter was found to be the most resistant of the bacteria investigated. In another study it was shown that the essential oil of thyme and especially its phenols, thymol and carvacrol, have antibacterial acivity against periodontopathic bacteria including Actinobacillus, Capnocytophaga, Fusobacterium, Eikenella, and Bacteroides species, and Read more […]

Bioactivity of Basil: Antifungal Activity

The antifungal activity of Ocimum leaves, extracts, essential oils and their components is frequently studied, mostly in warm countries where the need for protection of plants and stored crops against fungi is of great importance. Also the effect of Ocimum oils against a number of dermatophytes has been studied. Protection of plants and stored crops An ethanolic extract of Ocimum sanctum was used to treat healthy ripe tomato fruits prior to and after inoculation with Aspergillus niger in the presence of Drosophila busckii. The treatment kept the fruits free from rotting for 5 to 7 days. The essential oil of Ocimum canum was effective against damping-off disease causing fungi, Pythium aphanidermatum, P.debaryanum and Rhizoctonia solani. Ocimum canum could control damping-off disease of tomato up to 50% in soil infected with P.aphanidermatum and up to 43% in soil infected with P.debaryanum. The essential oil was not phytotoxic and showed superiority over commonly used synthetic fungicides such as Agrosan G.N. and Captan. Pandey and Dubey determined the fungitoxic spectrum of Ocimum canum oil (500 μl/1) and found 100% inhibition of the growth of the following fungi: Fusarium oxysporum f. sp. ciceri, F.sesami, F.semitectum, Read more […]

Gloeophyllum odovatum (Brown Rot Fungus)

The Fungus and Its Secondary Metabolites The fruiting bodies of the brown rot fungus Gloeophyllum odovatum (Wulf. ex Fr.) Imaz. syn. Trametes, odorata (Wulf. ex Fr.) Osmoporus odoratus (Wulf. ex Fr.) (Aphyllophorales, Basidiomycetes) are found in coniferous forests, chiefly in northern and rocky mountains in central Europe, in Asia, and occasionally in North America. In Fennoscandia, the fungus grows mostly on old stumps of the Norway spruce [Picea abies (L.) Karst.], very rarely on pine (Pinus sylvestris L.). The perennial brown fruit bodies are knotty, wedge- or plate-like medium-sized or large. The young parts are ochraceous to light brown in color, later becoming dark brown to almost black or blackish gray. G. odovatum is not very common. The other known Gloeophyllum species are G. protactum, G. sepiarium, G. abietinum and G. trabeum. Only the fresh fruit bodies of G. odoratum produce a strong scent of aniseed, when it grows on spruce. The sporophore of the fungus is primarily interesting because of its volatiles; however, they also contain steroids. The principal volatiles from the fruiting body grown on spruce have been identified as aromatics, i.e., methyl p-methoxyphenylacetate (33.5%) accompanied by ethyl Read more […]

Arnica montana (Mountain Arnica)

Arnica montana (mountain arnica) is a very old medicinal plant. The flower and flower heads are widely used in phytotherapy in numerous preparations. They have a broad spectrum of effects: bacteriostatic, fungistatic, antiinflammatory, antirheumatic, cardiotonic, and antihyperlipidemic. The industrial demand for Arnica montana of a standardized quality in its active substances is inconsistent with the still practiced wild collection of mountain arnica, its protected status in several European countries, and the difficulties in its cultivation. There are four different approaches to meet the industrial demand for Arnica and guarantee the supply of a standardized plant drug or of its active substances: (1) improvement of the cultivation of Arnica montana; (2) cultivation of other Arnica species with a similar pharmacological effect; (3) micropropagation for the production of a standardized quality; (4) in vitro production of secondary metabolites in cell cultures. In this chapter, literature on the distribution and importance of Arnica species and on the conventional and biotechnical approaches to their improvement and production is reviewed, and prospects for the latter approaches are discussed. Botany, Read more […]

Vulvovaginitis: Antimicrobial Therapy

Antimicrobial herbs are used as primary treatments in cases of vulvovaginitis when due to infectious causes. For acute infections, they are generally used solely as topical applications. For recurrent cases, external application is combined with oral use. Internal treatment should focus on immune supporting and antimicrobial botanicals, including echinacea, garlic, goldenseal, Oregon grape root, Pau d’arco, astragalus, and various medicinal mushroom species such as maitake and reishi medicinal mushrooms. Also see site for a discussion on adaptogens and immune support. Numerous herbs have exhibited both broad spectrum and specific antimicrobial activities. Although treatment approaches vary with each of the different infectious causes of vulvovaginitis, antimicrobial herbs are usually applied generically regardless of the infectious agent. There appears to be little, if any risk of resistance with herbal treatments; however, labs specializing in delivering services to complementary and alternative medicine practitioners sometimes do sensitivity and specificity testing for natural agents with screening for vaginal infections. This is unnecessary except in chronic, recurrent, or intractable cases. Garlic Garlic is Read more […]

ANTIFUNGAL AGENTS

ANTIFUNGAL AGENTS are antimicrobial drugs used to treat infections caused by fungal microorganisms. They may be antibiotics produced naturally, or purely synthetic. Fungal infections are not usually a major problem in healthy, well-nourished individuals. But, superficial, localized infections, such as thrush (caused by Candida albicans), and athlete’s foot and ringworm (caused by Tinea fungi of the dermatomycoses group), are common. These can readily be treated with topical application of antifungals. Severe infections occur most frequently where the host’s immunity is low, e.g. following immunosuppression for transplant surgery or in AIDS. Unfortunately, the most potent antifungal drugs taken systemically tend to be toxic. Amphotericin is a complex amphoteric polyene ANTIBIOTIC that binds to cell membranes and forms a pore through which ions can pass, with consequences that include loss of potassium ions from within the cell. Since the antibiotic binds more readily to fungal cell membranes than mammalian, its action is relatively selective. It can potentiate the action of certain other antifungals, and it may be used with flucytosine. Also, it confers antifungal activity on rifampicin (normally antibacterial). As Read more […]

ANTIBIOTICS

ANTIBIOTICS are, strictly speaking, natural products secreted by microorganisms into their environment, where they inhibit the growth of competing microorganisms of different species. In common usage, the term is generally applied to a wide range of chemicals, whether directly isolated from mould ferments, their semisynthetic derivatives, or synthetic chemicals showing some structural similarities. Also, in everyday language the term is used to denote drugs with a selectively toxic action on bacteria or similar non-nucleated single-celled microorganisms (including chlamydia, rickettsia and mycoplasma), though such drugs have no effect on viruses. In this loose parlance even the sulphonamides may, incorrectly, be referred to as antibiotics because they are antimicrobial. More confusing is the fact that a number of antibiotics are used as cytotoxic agents in cancer chemotherapy (e.g. bleomycin): see ANTICANCER AGENTS. Further, partly because of the recent development of high-throughput screens for lead chemicals, a number of new drug chemical classes have arisen from antibiotic leads (e.g. the CCK antagonist asperlicin and derivatives, from Aspergillus spp.). The antimicrobial antibiotics have a selectively toxic Read more […]

Lavender: Actions

Lavender and several of its constituents have been tested for pharmacological activity. SEDATIVE/ANXIOLYTIC The sedative properties of the essential oil and its main constituents (linalool and linalyl acetate) were shown to have a dose-dependent effect in mice and to reverse caffeine-induced hyperactivity in mice, as well as reduce stress, as indicated by modulation of ACTH, catecholamine and gonadotropin levels in experimental menopausal rats, and reduce cortisol responses in infant Japanese macaques. Inhalation of lavender has also been shown to produce a dose-dependent anticonvulsant effect in both rats and mice. In human trials, inhalation of lavender has been shown to induce relaxation and sedation and to alter EEG responses, as well as significantly decreasing heart rate and increasing high-frequency spectral components to produce calm and vigorous mood states in healthy volunteers. Transdermal absorption of linalool without inhalation produced a decrease in systolic blood pressure and a smaller decrease of skin temperature with no effects on subjective evaluation of wellbeing in healthy human subjects, and another study found that lavender scent was associated with lower fatigue following an anxiety-provoking Read more […]