Per Mølgaard

Traditional Chinese medicine in treatment of hyperlipidaemia

In the search of new products for treatment of hyperlipidaemia with a low frequency of side effects a decoction of Crataegus cuneata, Nelumbo nucifera and Gynostemma pentaphylla has been tested. A reduction of triglyceride and cholesterol was seen.

Anthelmintic screening of Zimbabwean plants traditionally used against schistosomiasis

Extracts of 23 plant species used popularly against schistosomiasis in Zimbabwe were screened for their anthelmintic effect. Schistosomules of the trematode Schistosoma mansoni and cysticercoids of the cestode Hymenolepis diminuta were studied in vitro. The material consisted of 58 plant extracts, of which 37 killed the newly excysted cysticercoids within an hour, when incubated in a culture medium. Lethal concentrations varied from 0.8 to 103 mg/ml. All plant extracts showed activity against the tapeworms after 24 h. Ten of the best extracts were also tested against schistosomules. Five of these extracts showed activity. Lethal concentrations varied from 0.6 to 33.8 mg/ml of dry plant material. Extracts of stem and root from Abrus precatorius (Fabaceae), of root bark and leaves from Ozoroa insignis (Anacardiaceae) and of root bark from Zizyphus mucronata (Rhamnaceae) gave the best results against tapeworms. The best results against schistosomules were obtained with stem and root extracts from Abrus precatorius (Fabaceae) and stem bark from Elephantorrhiza goetzei (Mimosaceae). Although the activity of root and root bark extracts commonly used in traditional medicine was verified in this study, our results showed that also extracts from leaf and stem can be effective anthelmintics.

Caffeic acid esters as in vitro inhibitors of plant pathogenic bacteria and fungi

Abstract Seven caffeic acid derivatives were tested for their activity against two plant-pathogenic fungi and seven plantpathogenic bacteria. A determination of minimum inhibitory concentration (MIC) in solid media was used for the fungi, and for the bacteria agar diffusion, as well as determintion of the MIC in liquid media, were used. A distinct concentration related activity was seen for most of the compounds. The molar activity of the caffeoyl esters against the bacteria was similar to that of tartaric acid, higher than that of phenol, but much lower than that of streptomycin. For most host plants, their ‘own’ compounds were less active against their pathogens than foreign ones. Of the tested compounds, ferulic acid, caffeic acid, esculine, esculetin and orobanchoside were the most active against the two fungi, and similarly, ferulic acid and esculetin were the most active against the bacteria.

Chemotaxonomy and evolution of Plantago L.

Abstract.In continuation of our investigations of the genus Plantago L. (Plantaginaceae), sixteen species were investigated with respect to water-soluble glycosides. The iridoids auroside, strictoloside and globularicisin, as well as poliumoside, 3-[(4-β-D-glucopyranosyloxy)phenyl]propionic acid and 2-[4-(β-D-glucopyranosyloxy)phenyl]acetic acid were isolated from Plantago for the first time. The latter compound has not previously been isolated as a natural product. Sorbitol was the main carbohydrate in all the species investigated. The distribution of iridoids correlates well with the morphological classification of Rahn and also with a recently published molecular phylogenetic study of nuclear ribosomal and plastid DNA sequences. A new chemotaxonomic finding is an abundance of iridoid glucosides present in one of the two groups within subgenus Coronopus section Coronopus, while the other group lacks iridoids, supporting a subdivision of this section. Moreover, in subgenus Albicans, 10-benzoylcatalpol is a characteristic constituent of section Gnaphaloides, while the corresponding cinnamoyl ester globularin occurs in section Lanceifolia. In biosynthetic experiments, labelled epideoxyloganic acid and deoxygeniposidic acid were incorporated into aucubin and geniposidic acid in Plantago ovata, consistent with earlier findings, but no incorporation into asperuloside was observed. The evolution of biosynthetic pathways in Plantago is discussed.

Can phylogeny predict chemical diversity and potential medicinal activity of plants? A case study of amaryllidaceae

BackgroundDuring evolution, plants and other organisms have developed a diversity of chemical defences, leading to the evolution of various groups of specialized metabolites selected for their endogenous biological function. A correlation between phylogeny and biosynthetic pathways could offer a predictive approach enabling more efficient selection of plants for the development of traditional medicine and lead discovery. However, this relationship has rarely been rigorously tested and the potential predictive power is consequently unknown.ResultsWe produced a phylogenetic hypothesis for the medicinally important plant subfamily Amaryllidoideae (Amaryllidaceae) based on parsimony and Bayesian analysis of nuclear, plastid, and mitochondrial DNA sequences of over 100 species. We tested if alkaloid diversity and activity in bioassays related to the central nervous system are significantly correlated with phylogeny and found evidence for a significant phylogenetic signal in these traits, although the effect is not strong.ConclusionsSeveral genera are non-monophyletic emphasizing the importance of using phylogeny for interpretation of character distribution. Alkaloid diversity and in vitro inhibition of acetylcholinesterase (AChE) and binding to the serotonin reuptake transporter (SERT) are significantly correlated with phylogeny. This has implications for the use of phylogenies to interpret chemical evolution and biosynthetic pathways, to select candidate taxa for lead discovery, and to make recommendations for policies regarding traditional use and conservation priorities.

Food plant preferences by slugs and snails: A simple method to evaluate the relative palatability of the food plants

Food plant selection by herbivores is of major importance in relation to plant population dynamics and plant selection in natural ecosystems as well as to crop protection. Slugs and snails are of major importance in this connection, and the proposed method is a valuable tool in the evaluation of their food plant preference. In the test, ten snails or slugs are given the choice between two alternative test plants at the same time. A logarithmic scale from 1 to 5 indicates the eating index, E, and from this figure a preference value, P, is derived by the formula P = El√t×1000, where t is the time in minutes. Using Helix pomatia and Arion ater, a preference scale has been obtained for selected plant species. From this scale it may be deduced that plants containing potent constituents against mammals are readily accepted by land molluscs, whereas plants generally avoided by molluscs are those containing tannins and phenolics.

Novel inhibitory activity of the Staphylococcus aureus NorA efflux pump by a kaempferol rhamnoside isolated from Persea lingue Nees

OBJECTIVES To isolate a plant-derived compound with efflux inhibitory activity towards the NorA transporter of Staphylococcus aureus. METHODS Bioassay-guided isolation was used, with inhibition of ethidium bromide efflux via NorA as a guide. Characterization of activity was carried out using MIC determination and potentiation studies of a fluoroquinolone antibiotic in combination with the isolated compound. Everted membrane vesicles of Escherichia coli cells enriched with NorA were prepared to study efflux inhibitory activity in an isolated manner. RESULTS The ethanolic extract of Persea lingue was subjected to bioassay-guided fractionation and led to the isolation of the known compound kaempferol-3-O-α-L-(2,4-bis-E-p-coumaroyl)rhamnoside (compound 1). Evaluation of the dose-response relationship of compound 1 showed that ethidium bromide efflux was inhibited, with an IC(50) value of 2 μM. The positive control, reserpine, was found to have an IC(50) value of 9 μM. Compound 1 also inhibited NorA in enriched everted membrane vesicles of E. coli. Potentiation studies revealed that compound 1 at 1.56 mg/L synergistically increased the antimicrobial activity of ciprofloxacin 8-fold against a NorA overexpresser, and the synergistic activity was exerted at a fourth of the concentration necessary for reserpine. Compound 1 was not found to exert a synergistic effect on ciprofloxacin against a norA deletion mutant. The 2,3-coumaroyl isomer of compound 1 has been shown previously not to cause acute toxicity in mice at 20 mg/kg/day. CONCLUSIONS Our results show that compound 1 acts through inhibition of the NorA efflux pump. Combination of compound 1 with subinhibitory concentrations of ciprofloxacin renders a wild-type more susceptible and a NorA overexpresser S. aureus susceptible.

Mauritian red nectar remains a mystery

Floral nectar is rich in chemicals and induces pollination. Although it may be tainted by algae or mould, it usually lacks colouring agents. However, a few plant species in Mauritius break this rule and produce red nectar. We attempted to find a function for this coloration, but its role remains unclear.

Asháninka medicinal plants: a case study from the native community of Bajo Quimiriki, Junín, Peru

BackgroundThe Asháninka Native Community Bajo Quimiriki, District Pichanaki, Junín, Peru, is located only 4 km from a larger urban area and is dissected by a major road. Therefore the loss of traditional knowledge is a main concern of the local headman and inhabitants. The present study assesses the state of traditional medicinal plant knowledge in the community and compares the local pharmacopoeia with the one from a related ethnic group.MethodsFieldwork was conducted between July and September 2007. Data were collected through semi-structured interviews, collection of medicinal plants in the homegardens, forest walks, a walk along the river banks, participant observation, informal conversation, cross check through voucher specimens and a focus group interview with children.ResultsFour-hundred and two medicinal plants, mainly herbs, were indicated by the informants. The most important families in terms of taxa were Asteraceae, Araceae, Rubiaceae, Euphorbiaceae, Solanaceae and Piperaceae. Eighty-four percent of the medicinal plants were wild and 63% were collected from the forest. Exotics accounted to only 2% of the medicinal plants. Problems related to the dermal system, digestive system, and cultural belief system represented 57% of all the medicinal applications. Some traditional healers received non-indigenous customers, using their knowledge as a source of income. Age and gender were significantly correlated to medicinal plant knowledge. Children knew the medicinal plants almost exclusively by their Spanish names. Sixteen percent of the medicinal plants found in this community were also reported among the Yanesha of the Pasco Region.ConclusionsDespite the vicinity to a city, knowledge on medicinal plants and cultural beliefs are still abundant in this Asháninka Native Community and the medicinal plants are still available in the surroundings. Nevertheless, the use of Spanish names for the medicinal plants and the shift of healing practices towards a source of income with mainly non-indigenous customers, are signs of acculturation. Future studies on quantification of the use of medicinal plants, dynamics of transmission of ethno-medicinal knowledge to the young generations and comparison with available pharmacological data on the most promising medicinal plants are suggested.

Investigation of the diurnal, ontogenetic and seasonal variation in the molluscicidal saponin content of Phytolacca dodecandra aqueous berry extracts

Daily variation in the content of the saponins of the berries of Phytolacca dodecandra was determined in berries harvested at the full grown green unripe stage of development once every two hours. The saponin content was quantitatively determined by HPLC analysis of the molluscicidal monodesmosidic saponins in the aqueous extract of the crushed berries. No significant daily variations were observed in extracts of berries collected at different times of day (P > 0.05 by ANOVA). But, seasonal variation was apparent in extracts prepared from berries harvested from the same plants once every two weeks. Berries of highest saponin content were those harvested during the dry season and just before the onset of the rainy season. The seasonal variation was attributed to increased water stress during the dry season. Very young racemes had the highest saponin content, while mature berries produced the lowest saponin concentration. There was, however, consistency in the berry saponin composition during the day, season and all stages of berry development.