J. H. Zwaving

AYURVEDIC HERBAL DRUGS WITH POSSIBLE CYTOSTATIC ACTIVITY

Ayurveda is considered to be the traditional science of health in India and is based on the principle of subjectivity. All matter is composed of five basic elements, which can be perceived by the five sense organs. All food and drugs are classified according to their pharmacological properties, which are derived from these five elements. To investigate which Ayurvedic plants might have cytostatic activity, an Ayurvedic model for the pathogenesis of cancer was made. Based on this, selection criteria were formed, that were used to select plants from a list of Ayurvedic herbal drugs. Some of the selected species could be collected in India and Nepal. The dried material of 14 species was submitted to ethanol (70% v/v) extraction and the extracts were tested for cytotoxicity on COLO 320 tumour cells, using the microculture tetrazolium (MTT) assay. The IC50-value, the concentration causing 50% growth inhibition of the tumour cells, was used as a parameter for cytotoxicity. Extracts of the flowers of Calotropis procera (Ait.) R. Br. (Asclepiadaceae) and of the nuts of Semecarpus anacardium L.f. (Anacardiaceae) displayed the strongest cytotoxic effect with IC50-values of 1.4 micrograms/ml and 1.6 micrograms/ml, respectively. The extracts of several other plants did not show a cytotoxic effect up to 100 micrograms/ml, the highest concentration tested.

Epicuticular wax composition of some European Sedum species

Abstract Epicuticular waxes from 30 species of Sedum and 2 species of Sempervivoideae, i.e. Aeonium spathulatum and Sempervivum nevadense , have been analysed by GC and GC-MS. The Sedum taxa examined were S. acre , S. album , S . series Alpestria (13 species), S. anglicum , S. brevifolium , S. litoreum , S. lydium , S . series Macaronesia (four species), S. melanantherum and S . series Rupestria (five species) of S . sect. Sedum and S. meyeri-johannis of S . sect. Africana . The waxes consist of alkanes, alkanols, fatty acids, fatty acid methyl esters, aldehydes, wax esters and triterpenes. Some 14 triterpenes were detected in waxes of Sedum , the major triterpenes being β-amyrenyl acetate, germanicyl formate (not previously reported from a natural source), multiflorenyl acetate and taraxeryl acetate. Waxes of the pruinose and glaucous taxa of Sedum were found to have a high triterpene content. In waxes of Aeonium spathulatum and Sempervivum nevadense , no triterpenes could be detected. Variation in the alkane and triterpene profiles proved to be of significant systematic value. In general, the distribution of the triterpenes in Sedum agrees with the infrageneric classification based on hybridization patterns and related morphological characters.

DISTRIBUTION OF ALKALOIDS AND TANNINS IN THE CRASSULACEAE

Abstract Alkaloid and tannin levels of 36 species of the Crassulaceae were compared. The taxa investigated were Crassula multicava , Echeveria venezuelensis , Pachyphytum compactum , Kalanchoe (two spp.), Bryophyllum daigremontianum , Sedum (23 spp.), Aeonium (four spp.) and Sempervivum (three spp.). Apart from the alkaloidal species of Sedum , only E. venezuelensis was found to contain piperidine alkaloids, i.e. pelletierine and N -methyl pelletierine. Proanthocyanidins (condensed tannins) and galloyl esters were found in all genera, but they were absent from six out of 11 Sedum species containing piperidine alkaloids. The results indicate a dichotomy between the distribution of alkaloids and tannins, which is in good agreement with the major evolutionary trends within the family as inferred from chloroplast DNA restriction site variation. The distribution of alkaloids appears to be limited to the “ Acre ” lineage, which comprises the Asian, Eurasian and American Sedum species with a reticulate testa as well as the Central American Sedoideae and Echeverioideae. The parallel occurrence of alkaloids and a complex of apparently primitive flower and seed characters in the terminal “ Acre ” clade indicate the derived rather than the primitive condition of the latter features. The most parsimonious explanation for this marked inconsistency is a reversal of the floral structure at the basis of the “ Acre ” lineage, mimicking the floral structure of ancestral angiosperms.

INVESTIGATION OF GREWIA-BICOLOR JUSS

Grewia bicolor is a small tree, parts of which are used in Sudanese traditional medicine for treating pustulent skin lesions, internally on indication of a delayed afterbirth and sometimes as a tranquilizer. A phytochemical investigation of Grewia bicolor gave the following results: the petroleum ether extract afforded beta-sitosterol and beta-sitosterol- and triterpene esters, and the triterpenes lupeol and betulin. The methanol extract afforded: beta-sitosterol-glucoside and three alkaloids, harman, 6-methoxyharman and 6-hydroxyharman. The latter is the main alkaloid. The methanol extract shows activity against gram-positive and gram-negative organisms and causes a strong contraction of the isolated rat uterus which can be blocked by methysergide.

THE ESSENTIAL OIL OF APIUM-GRAVEOLENS VAR SECALINUM AND ITS CERCARICIDAL ACTIVITY

The composition of the essential oil of the fresh aerial parts ofApium graveolens var.secalinum at its flowering stage, obtained from three different locations in Egypt, was investigated. The identification of the components of this oil was carried out by means of analytical GC and GC-MS. The main components in the oil are: α- and Β-pinene, myrcene, limonene,cis-Β-ocimene, γ-terpinene,cis-allo-ocimene,trans-farnesene, humulene, apiol, Β-selinene, senkyunolide and neocnidilide. Data concerning the relative concentrations of the main components of the different celery oil samples are given. The cercaricidal effect of the essential oil has been examined on cercariae, being one of the stages in the life cycles ofSchistosoma mansoni, which causes schistosomiasis. The essential oil showed in addition to a cercaricidal effect also a chemotactic effect.

GAMMA-IRRADIATION OF SENNAE FOLIUM - MICROBIOLOGICAL AND PHYTOCHEMICAL STUDIES

The effect of different doses of gamma irradiation on senna leaves was studied. No changes in sennoside content and composition were observed after irradiation with 25 kGy. It was demonstrated that a minimum dose of 10 kGy was necessary to obtain a product of good microbiological quality. Cold maceration of senna leaves has to be discouraged, because of unavoidable microbial growth. Hot extraction is the method of choice for tea preparation. The rationale of gamma irradiation is discussed.

Alkaloids in ergot found on different Gramineae in The Netherlands

AbstractThe alkaloid content and the composition of the alkaloid complex of thirteen samples of ergot sclerotia from different gramineous host species collected in The Netherlands were investigated. Two samples collected in France were also examined. Ergot ofGlyceria fluitans (L.) R.Br. did not contain alkaloids. The total alkaloid content of ergot found on the other wild grasses was more than 0.2%. The ratio between the contents of water soluble and water insoluble alkaloids of the investigated ergot sclerotia varies between 1∶10 and 1∶20. The composition of the alkaloid complex in the sclerotia was studied by quantitative thin-layer chromatography. The sclerotia could be grouped into three main categories:sclerotia ofLolium perenne L.,Festuca arundinacea Schreb. andArrhenatherum elatius (L.) P.B. ex J. et C. Presl, containing predominantly ergocornine, α- and β-ergokryptine and ergosine;sclerotia ofDactylis glomerata L.,Phalaris arundinacea L.,Alopecurus geniculatus L. andHolcus mollis L., containing predominantly ergosine, ergocristine and ergotamine;sclerotia ofMolinia caerulea (L.) Moench, containing predominantly ergocristine, ergosine and ergqmetrine. A great similarity was found between the composition of the alkaloid complex in ergot ofLolium perenne L. from different locations and also in ergot ofMolinia caerulea (L.) Moench from different locations. This similarity was less in ergot ofDactylis glomerata L. collected from different locations.

Orthosiphon stamineus, een geneeskruid met een diuretische werking

In this paper a survey is given of the phytochemical and pharmacological research, known until now, into the active principles of the leaf drugOrthosiphon stamineus Benth., which is used therapeutically for diseases of the kidneys and the bladder and as a diuretic. Although a high potassium content and the presence of inositol have been claimed for the activity no clear relationship exists between these constituents and the pharmacological effects. Other constituents as for instance not fully identified saponins may possibly play a role and flavonoids and their metabolites would be responsible for the bacteriostatic activity of Orthosiphon. An investigation is in progress in our laboratory to elucidate these problems.SamenvattingIn dit artikel wordt een overzicht gegeven van het tot dusver bekende fytochemisch en farmacologisch onderzoek naar de werkzame bestanddelen van de bladeren vanOrthosiphon stamineus Benth., dat als geneeskruid wordt toegepast bij nier- en blaasziekten en als diureticum. Hoewel een hoog kaliumgehalte en de aanwezigheid van inositol in het kruid wel verantwoordelijk worden gesteld voor de werking, is er nog geen duidelijke relatie tussen deze bestanddelen en de farmacologische effecten. Mogelijk zouden ook andere stoffen een rol kunnen spelen, zoals nog niet volledig geÏdentificeerde saponinen, terwijl flavonoÏden en hun omzettingsprodukten verantwoordelijk zouden kunnen zijn voor de bacteriostatische werking van Orthosiphon. In ons laboratorium is een onderzoek begonnen teneinde hierover opheldering te verschaffen.

SOME ADAPTATIONS IN THE METHOD OF THE PHARMACOPOEIA HELVETICA EDITIO SIXTA FOR THE DETERMINATION OF TOTAL ALKALOIDS IN STRYCHNOS SEEDS

Strychnos seeds, from Strychnos nux. vomica L. and other S. species, are being used in several countries, especially in Africa and Asia. In Vietnam they are widely used for the preparation of antirheumatic drugs. The activity is ascribed to the presence of several alkaloids in the seeds. Within the scope of attempts to obtain an optimal extraction and separation method of the alkaloids, the method of the Swiss pharmacopoeia has been chosen for quantitative determination of the total alkaloid content in different kinds of Strychnos seeds. The results with this method, which is timeconsuming, are not satisfactory. This can be caused by the following facts: i t is possible that an incomplete extraction is obtained using the extraction method according to the Swiss pharmacopoeia, in which 3;00 g of ground drug is shaken during 30 min with a mixture of 3 ml of a I2.4% wt/vol solution of sodium carbonate monohydrate, IO.O g of chloroform and :~o.o g of ether, followed by.addition of 7 ml of water and further shaking for a few minutes. In this case there is perhaps incomplete transport of the alkaloids as free bases from the plant cell to the organic solvent; an emulsion is often formed using this extraction procedure. Filtration of this emulsion through a cotton plug is time-consuming and causes an uncontrolled loss of solvent by evapor,ation. However, this leads to a higher calculated alkaloid content than is actually present. After a number of experiments the following changes have been introduced into the original method. First: the ground seeds are immersed during I h in a flask fitted with a ground-glass stopper with 3 ml of the same sodium carbonate monohydrate solution and 7 ml of water under occasional shaking, followed by the addition of the mixture consisting of IO.O g of chlorof0~tn and 20.0 g of ether, which is carefully mixed with the content of the flask. Second: the mixture is decanted as quickly as possible, thus avoiding the filtration step. The amount of decanted extract is determined by the difference in weight of the beaker containing the mixture before and afte r decanting. The amount of solvent lost by evaporation has been reduced in this way. The other steps are carried out as indicated in the Swiss pharmacopoeia. The results of the adapted method with respect to the pharmacopoeia method are given in Table i. Using the Fand the t-test respectively, 2 the conclusion can be drawn that the relative standard error of both methods does not differ but that the mean percentage of total alkaloids determined by the adapted method is statistically higher than the original method of the Swiss pharmacopoeia. This means that the precision of the adapted method is at least comparable with that of the original method and that a better extraction of the seeds has been obtained. The latter is supported by the fact that a positive error, due to evaporation of the solvent, is almost omitted.