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| Rhamnus frangulae cortex |
Niet dat ik veel schors van bomen of struiken oogst. Toch is het nu ook het moment om medicinale schors te verzamelen bvb de ongeveer 3 jaar jonge takken van Rhamnus frangula.
Vuilboom, sporkehout, pijlhout, sprokkel, houtjeshout, bloedboom, stinkboom en buskruithout. Allemaal namen van de Rhamnus frangula die met zijn gespikkeld hout de schaduwrijke randen van onze bossen bevolkt. Ook allemaal namen die wat vertellen over het vroeger gebruik.
Rhamnus cathartica L., die in ons land vrij zeldzaam voorkomt in bosachtige streken en in de duinen. Dit voorkomen van doornen, die echter ontbreken bij Rhamnus frangula, schijnt tot de naam Rhamnus geleid te hebben. Het Keltische woord "ram" betekent namelijk doornstruik. Het woord frangula is afgeleid van het Latijnse "frangere, breken en heeft betrekking op de breekbaarheid van het hout. De Nederlandse naam vuilboom houdt verband met de onaangename geur van de verse bast, al wordt er ook wel eens beweerd dat deze naam te maken heeft met het laxerend effect, zeg maar het vuil dat wordt uitgescheiden. Meer lezen over dit oude laxeerkruid http://mens-en-gezondheid.infonu.nl/alternatief/35573-vuilboom-of-sporkehout.html
Wetenschappelijk onderzoek en werking vlgs EMEA
Frangula bark belongs to the stimulant laxatives. Emodin-9-anthrone is the most important metabolite, which is produced by the bacteria of the large intestine. The mode of action is based on two mechanisms. Firstly, colonic motility is increased leading to a reduced transit time. Secondly, an influence on secretion processes by two concomitant mechanisms, namely inhibition of absorption of water and electrolytes (Na + , Cl - ) into the colonic epithelial cells (antiabsorptive effect) and increase of the leakiness of the tight junctions and stimulation of secretion of water and electrolytes into the lumen of the colon (secretagogue effect), results in enhanced concentrations of fluid and electrolytes in the lumen of the colon. These findings are based on investigations with different anthrones deriving also from other anthranoid-containing herbal substances, but the results of these investigations are not always consistent
Results of investigations of Capasso F et al. 1983 (55) in rat isolated colon suggest that the laxative properties of aloin and 1,8-dihydroxyanthraquinone may depend, at least in part, on increased prostaglandin synthesis by the intestinal tissue. Frangula bark predominantly contains the anthranoids as anthraquinones. Therefore it is supposed that the influence of frangula bark on fluid absorption and on secretion processes is lower than the influence of other anthranoid-containing herbal substances. Data of a direct clinical comparison of the effects are missing (8).
Cressari A et al. 1966 (11) investigated different constituents of the frangula bark to evaluate the laxative effect in comparison to a standard senna leaves extract (amount of anthranoids not mentioned) in mice. Glucofrangulin and frangulin only showed a laxative effect after oral administration. This effect was nearly 4 to 5 times stronger than the effect of the senna extract. The effect of emodin was comparable with the effect of the senna extract. Physcion and chrysophanol had no noteworthy effect. The administration of a methanolic extract of frangula bark (17.5 % anthranoid glycosides calculated as 1,8-dihydroxyanthraquinon-glycoside) in mice resulted in a dose dependent decrease of the intestinal transit time. After oral administration of 50 mg/kg body weight defaecation after 4 h took place in 20 % of the mice, after oral administration of 100 mg/kg body weight in 40 %. The ED 50 was mentioned with 121.5 mg/kg body weight (12, 13). A methanolic extract of frangula bark (23 % glucofrangulin, 2 % frangulin, 0.5 % aglyka) had a laxative effect in mice with a weight of 20 g after oral administration. The ED 50 was 3.66 mg/20 g body weight. The ED 50 of another frangula extract with 25 % glucofrangulin, 1.5 % frangulin and 0.5 % aglyka was 2.45 mg; the ED 50 of pure glucofrangulin A was 7.97 mg, of pure frangulin A 2.37 mg and of pure emodin 4.67 mg /20 g body weight (7). The administration of an aqueous suspension of 0.6 g pulverised bark (12 mg anthranoids (glucofrangulin and frangulin) had a laxative effect in humans after 6 to 24 h (12, 14)
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