J. J. C. Scheffer

ANTI-INFLAMMATORY, ANTIPYRETIC AND ANTINOCICEPTIVE ACTIVITIES OF TABERNAEMONTANA PANDACAQUI POIR

Studies on carrageenin-induced rat paw edema, yeast-induced hyperthermia in rat and writhing response induced by acetic acid in mice showed that the alcoholic extract of stems of Tabernaemontana pandacaqui (T. pandacaqui) has significant anti-inflammatory, antipyretic and antinociceptive activities. These activities are due to alkaloidal components since they were also observed when the crude alkaloidal (CA) fraction separated from alcoholic extract was tested in the same models.

Antimicrobial activities of essential oils

The testing of essential oils for antimicrobial activities is reviewed with respect to various possible applications. Consideration is given to the screening for antimicrobially active oils or constituents, for disinfecting or antiseptic properties and for food conserving properties. The role of essential oils in biological interactions and their potential as therapeutic agents are also discussed.

Screening for antimicrobial activity of some essential oils by the agar overlay technique

Fifty-three essential oils were tested against five micro-organisms (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans) using the agar overlay technique. The essential oils were randomly selected and not on the basis of a supposed activity. It was found that all oils showed an activity against at least one micro-organism, and that substantial activities againstP. aeruginosa were scarce. Combined activities againstC. albicans, the Gram-positive bacteria andE. coli, and an activity againstC. albicans were most often observed. Secondly a combined activity againstC. albicans, B. subtilis andS. aureus was found. The differences between the inhibition zones were too small for a differentiation of the antimicrobial activities of the essential oils. A correlation matrix shows the relationships of the micro-organisms as to the activity patterns of the essential oils. High correlations were found for all the micro-organisms, except forP. aeruginosa.

Essential oils from hairy root cultures and from fruits and roots of Pimpinella anisum

Abstract Hairy root cultures of Pimpinella anisum were established following inoculation of aseptically grown plantlets with an A 4 pRiA 4 70 GUS strain of Agrobacterium rhizogenes . The essential oils from the hairy roots, maintained in four different media, and from the fruits and roots of the parent plant were analysed and their compositions compared by GC and GC-mass spectrometry. The major components of the essential oils from the hairy root cultures were trans -epoxypseudoisoeugenyl 2-methylbutyrate, geijerene, pregeijerene, zingiberene and β-bisabolene, in varying amounts depending on the light or dark growth conditions and on the culture media tested. trans -Epoxypseudoisoeugenyl 2-methylbutyrate, β-bisabolene and pregeijerene were the major components of the essential oil from the roots of the parent plant, whereas the main component of the fruit oil was trans -anethole. Geijerenes were not detected in the fruit oil. The essential oil yield of the transformed roots grown in one of the media was comparable with that obtained for the roots of the parent plant and, calculated on a dry weight basis, the oil yield of these hairy roots was comparable with that of the fruits.

Antimicrobial activities of some ocimum species grown in rwanda

The essential oils of four Ocimum species grown in Rwanda, i.e. O. canum, O. gratissimum, O. trichodon and O. urticifolium (synonym O. suave) including some chemotypes, were screened for antimicrobial activities. Escherichia coli, Bacillus subtilis, Staphylococcus aureus and Trichophyton mentagrophytes var. interdigitale were used as test organisms. Different techniques were applied in the screening, such as the biogram and agar overlay techniques and a dilution technique yielding maximum inhibitory dilution (MID) values. Also some growth curves were determined. Although the results obtained by the diffusion techniques were rather different for some of the oil samples, all samples were found to be antimicrobially active.

Analytical aspects of phytotherapeutic valerian preparations

A high performance liquid chromatographic method combined with diode array detection is described by which the valerian constituents valtrate, isovaltrate, acevaltrate, didrovaltrate, isovaleroxyhydroxydidrovaltrate, valerenic acid, hydroxyvalerenic acid and acetoxyvalerenic acid, as well as the valepotriate decomposition products baldrinal and homobaldrinal, can be separated and identified simultaneously. Using this procedure, roots of Valeriana officinalis, which are used for the production of phytomedicines, were analysed. The influence of different ethanol:water mixtures, used as extraction liquid, on the composition of extracts of V. officinalis is reported. The analytical procedure was also applied to a number of valerian-containing phytomedicines available on the Dutch market. In order to study the stability of the valepotriates and the formation of their decomposition product(s), samples of freshly prepared valerian tinctures were analysed after being stored at 4, 20, and 36 degrees C for up to one month.

Plectranthus madagascariensis: Morphology of the Glandular Trichomes, Essential Oil Composition, and Its Biological Activity

Glandular and nonglandular trichomes are spread over the vegetative and reproductive organs of Plectranthus madagascariensis. Two morphologically distinct types of glandular trichomes (capitate and peltate) are described. Capitate trichomes have an ovoid unicellular head and a short stalk cell or an elongated two- to three-celled stalk slightly enlarged at the base. Peltate trichomes, which show in vivo a characteristic orange-to-reddish color, are large, flattened-to-depressed in the center, and often appear as a ring of minute gems. They are composed of a large head with eight glandular cells arranged in a single layer. An unusual kind of capitate trichomes, reported for the first time in Lamiaceae, occurs typically restricted to the calyx. These trichomes possess a two- or three-celled stalk and a long, unicellular conical, glandular head. The several types of trichomes differ in the secretion process The essential oils of P. madagascariensis, isolated by hydrodistillation and by distillation-extraction separately from flowers and from leaves collected during the flowering and the vegetative phases of the plant were analyzed by gas chromatography and gas chromatography-mass spectrometry (GC and GC-MS). The main component of the oils was a diterpene, 6,7-dehydroroyleanone, isolated as orange-to-reddish crystals, which represented 28%, 87%, and 41% of the oils from the flowers and from the leaves collected during the flowering and vegetative phases, respectively. The essential oils of P. madagascariensis showed bactericidal activity against Bacillus subtilis, Micrococcus sp., Staphylococcus aureus, and Yersinia enterocolitica, and revealed a modest antioxidant activity.

In-vitro prenylation of aromatic intermediates in the biosynthesis of bitter acids in humulus lupulus

Abstract Bitter acids are accumulated in the glandular hairs of hop cones. The first step of the biosynthesis of the bitter acids, namely formation of the aromatic intermediates, is catalysed by a chalcone synthase-like enzyme. In the present paper two sequential prenylation steps, leading to first the production of compounds X (4-prenylphlorisovalerophenone) or co-X (4-prenylphlorisobutyrophenone) and thereafter to the production of deoxyhumulone or deoxycohumulone, respectively, are described. An HPLC assay for these prenylation reactions has been set up, and enzyme activities were measured in protein extracts from hop flowerbuds, flowers and young cones. Furthermore, preliminary characterization experiments of the prenyltransferases were performed.

Antimicrobial screening of essential oils and extracts of some Humulus lupulus L. cultivars.

The essential oils as well as solvent extracts of 11 hop cultivars, 1 hop variety and a wild type of hop were screened for their antimicrobial activities using the agar overlay technique. The oils were isolated from the cones of the various hop plants by hydrodistillation, the extracts were obtained by soaking the hop cones in chloroform. The oils and the extracts showed activity against the Gram-positive bacteria (Bacillus subtilis andStaphylococcus aureus) and the fungus (Trichophyton mentagrophytes var.interdigitale), but almost no activity against the Gram-negative bacterium (Escherichia coli) and the yeast (Candida albicans) used in the screening. The peak area percentages of the main volatile components and the contents of the bitter acids of the extracts were determined for all cultivars using chromatographic methods.

Cytotoxic potential of valerian constituents and valerian tinctures.

Underground parts of three Valeriana species, namely V. officinalis L. s.l., V. wallichii DC. (V. jatamansi Jones), and V. edulis Nutt. ex Torr & Gray ssp. procera (H.B.K.) F. G. Meyer (V. mexicana DC.), are used in phytotherapy because of their mild sedative properties. Characteristic constituents of these species, which are regarded also as the active principles, were tested for cytotoxicity against GLC(4), a human small-cell lung cancer cell line, and against COLO 320, a human colorectal cancer cell line, using the microculture tetrazolium (MTT) assay. Valepotriates of the diene type (valtrate, isovaltrate and acevaltrate) displayed the highest cytotoxicity, with IC50 values of 1-6 μM, following continuous incubation. The monoene type valepotriates (didrovaltrate and isovaleroxyhydroxydidrovaltrate) were 2- to 3-fold less toxic. Baldrinal and homobaldrinal, decomposition products of valepotriates, were 10- to 30-fold less toxic than their parent compounds. Isovaltral had a higher cytotoxicity than its parent compound isovaltrate. Valerenic acids (valerenic acid, acetoxyvalerenic acid, hydroxyvalerenic acid and methyl valerenate), which are characteristic for V. officinalis, had a low toxicity with IC(50) values between 100 and 200 μM. Freshly prepared and stored tinctures, prepared from roots and rhizomes of the three valerian species, were analysed for valepotriates, baldrinals and valerenic acids, and also tested for cytotoxicity. There was a clear relationship between the valepotriate contents of the freshly prepared tinctures and their toxicity. Upon storage, valepotriates decomposed, which was reflected in a significant reduction of the cytotoxic effect.