Buckthorn. Persian berry bark
Specification & Spread
Buckthorn bark — cortex frangulae
Persian berry — frangula alnus mill. ( = rhamnus frangula l.)
Buckthorn family — rhamnaceae
Other names: alder buckthorn, black dogwood, glossy buckthorn.
It is a high shrub or small tree 1-3 (7) m tall with smooth, alternately arranged branches without thorns.
The bark of young branches is reddish-brown, shiny, with transversely elongated whitish lentils; in old branches and stocks it is greyish-brown with lentils spreading into grey spots.
The leaves are alternate, acuminate-elliptic or obovate, entire, brilliant, smooth, with 6-8 pairs of parallel curved lateral veins of the first order.
The flowers are bisexual, pentamerous, small, greenish-white, gathered in bunches of 2-7 in the leaf axils.
The fruit is a juicy coenocarpic drupe with 2, less often with 1-3 stones, poisonous (!). When it ripes, the colour of the fruit changes from green to red and purple-black.
The stones are about 5 mm in length, broadly obovate, oblate, with beak-shaped outgrowth.
It flowers in May - June, it bears fruit in August - September.
Spreading. It grows in forest zone of the European part of the country, central regions of Western Siberia, Northern Kazakhstan, the Caucasus. In the north it grows the Arctic Circle, in Siberia it grows Altai and the r. Yenisei.
Habitat. It grows in the undergrowth of pine, partly spruce and mixed forests, often along the banks of rivers, lakes, the outskirts of marshes, in damp meadows among shrubs, along with willow, bird cherry, alder, rowan.
Buckthorn bark contains:
- up to 8% of anthracene derivatives -
- hetero-and diantrons of frangulin,
- as well as monomeric compounds in both reduced and oxidized forms (glucofrangulin, frangulin, frangulaemodine).
In the fresh buckthorn bark, restored forms dominate -
- primary antraglycoside frangularose, possessing emetic properties,
- anthranols and anthrones capable of spontaneous oxidation. During long-term storage or heating of the raw material, their oxidation occurs and enzymatic hydrolysis with the formation of various intermediate products, in particular, frangularoside is oxidized by enzymes to glucofrangulin, the aglycone of which is frangulaemodin.
Therefore, the use of buckthorn bark GF XI recommends only one year after the procurement of raw materials.
The storage for a year can be replaced by heating the raw material at a temperature of 100 °C for one hour.
Buckthorn bark, which has been heat-treated or stored for at least 1 year, goes on sale, therefore, it can be in the buckthorn bark ready for medical use at the same time:
- frangulin and
- as well as chrysophanol.
Harvesting and storage of raw materials
Harvesting. Buckthorn bark is harvested in early spring, during the period of bud swelling, before flowering begins. At this time, the bark is easily separated from the wood. In the places designated by forestry, the buckthorn is cut down with an ax or cut with a hacksaw, leaving 10-15 cm of hemp to be resumed. On the felled stalks and thick branches, it makes circular cuts at a distance of 25-30 cm from each other, which are connected by a longitudinal incision. Remove the bark in the form of grooved or tubular pieces. It is impossible to soothe the bark with a knife, as the pieces are narrow and contain wood residues. The bark is cleaned from lichens. The harvesting is carried out with plants not younger than 8 years old and at least 3 m high.
Security measures. Harvesting of bark is carried out only with the permission of forestry in designated areas. The repeated harvesting in the same place is possible in 10-15 years. The work is underway on the introduction of buckthorn in culture.
Drying. Buckthorn bark is dried outdoors under sheds or well ventilated attics. Lay out a thin loose layer, periodically overturned, making sure that the pieces of bark are not put into each other. While drying in the open air for the night it is covered with a tarpaulin or entered into the room. Drying is considered complete when the bark ceases to bend and breaks with a bang. After drying, blackened lumps and bark are taken from the raw material with wood residues on the inside.
While harvesting by inexperienced collectors, it is possible to collect the bark of other related plants - buckthorn, alder, mountain ash, bird cherry and various species of willow. The buckthorn bark is different in that when the outer layer of the bark is scraped off, a raspberry-red, so-called frangulin layer is found, which is brown or green in impurities.
Storage. It is stored in a dry, well-ventilated area and packed. The bark is pressed and packed in bales.
External signs of raw materials
Whole raw materials
There are the tubular or fluted pieces of bark of various lengths and 0.5-2 mm thick.
The outer surface of the bark is more or less smooth, dark brown, grey brown, dark grey or grae, often with whitish transversely lenticular or gray spots; a slight scraping of the outer part of the tube reveals a crimson-red layer.
The inner surface is smooth, yellowish orange or reddish brown.
The fracture is light yellow and evenly finely grated. The smell is weak. The taste is bitter.
Milled raw materials
The pieces of bark of various shapes are passing through a sieve with 7 mm diameter holes.
The colour of the bark on the outer side is dark brown, grey-brown, dark grey or grey, from the inside it is yellowish-orange or reddish-brown.
The smell is weak. The taste is bitter.
The yellow-brown powder is passing through a sieve with holes of 0.16 mm.
The smell is weak. The taste is bitter.
The medicinal use is also allowed for Imeretian buckthorn bark (Rhamnus imeretina Booth), from which a liquid extract is prepared.
Properties and application
Buckthorn bark has:
- laxative effect after 8-10 hours after taking the preparations.
The large latent period is due to the slow hydrolysis of antraglycosides by enzymes and bacterial flora of large intestines in an alkaline medium. The glycosides itself are inactive. Due to the fact that the glycosides do not disintegrate in the upper intestine, the movement of food masses through the small intestines is not accelerated. Glycosides begin to disintegrate only in the large intestines, where the laxative effect associated with stimulation of the lower intestinal receptor is manifested. The effect is sometimes accompanied by pains of a colicky character or tenesmus.
Buckthorn preparations slow down absorption from the intestine, resulting in an increase in intestinal contents. The increase in volume and the dilution of fecal masses are an additional laxative factor.
Application of buckthorn
Buckthorn preparations are used:
- with chronic habitual constipation, which often develops in people with poorly developed abdominal muscles and leading a sedentary lifestyle.
Long-term use of buckthorn preparations leads to addiction, so you need to increase the dose or periodically change the laxative.
- Increased individual sensitivity to the components of the preparation,
- constipation of neurogenic and endocrine origin,
- spastic constipation
- intestinal obstruction,
- acute abdominal syndrome,
- other inflammatory processes in the abdominal cavity,
- acute feverish states.
- Pregnancy, breastfeeding period.