Page 260 - Pharmacognosy 2 PG303

Pharmacognosy-2 (PG303) Level 2 Clinical Pharmacy-Pharm D

Cultivation and collection
In cultivating aconite, young tubercles are planted in the autumn, well spaced
in rows, early in the following spring. The terminal bud on the crown of each root
forms a flowering stem end in the axil of scale leaves at its base, from one to several
buds develop at the ground level into short lateral shoots. Each of which forms at its
extremity a root crowned by a bud. These roots gradually enlarge and become
filled with reserves forming plump conical roots, each with a bud at the apex and
known as daughter roots. The parent root gradually shrivels as its reserves are
used for the production of the aerial plant, which flowers in July. Each plant
usually produces several daughter roots which may be as many as six. When
the field is dug sufficient of the daughter roots are reserved for replanting and
the remainder are well washed and brushed in water and are sometimes deprived of
the wiry side roots. They are finally dried in warm air in drying sheds. The plots are
dug every other year and by using 2 plots alternately a regular yearly yield is
ensured. The English drug is produced in this way and therefore consists of
daughter roots. This method of cultivation yields a drug which is known to
have been obtained from the correct species of aconitum. If seed is used to raise
the plants, uncertainty as to botanical source results, because other varieties of
aconitum are grown as garden plants and hybrids are easily formed.

Macroscopical Characters
Odor, very slight, taste, slight with slight sweetness, followed by bitterness,
then numbness in the mouth. Aconite occurs usually entire, rarely longitudinally
sliced. Entire tubers are more or less obconical, 4-10 cm long, 1-3.5 cm abroad at
the crown and tapering to a point at the lower end. The daughter tuber is plumpy,
slightly ridged, surmounted by a large bud or its remains. While the parent tuber
is usually larger, more or less shriveled, strongly ridged or even grooved and
crowned by the remains of the basal part of an aerial stem, occasionally attached in
the upper part to a small daughter tuber. Externally, it is dark brown or greyish
brown, bearing numerous root scars or short thin wiry rootlets. Fracture, short.
Internally, it is light brown to dark brown. The T. S. shows a thick dark and wide
bark and pale pith, both being separated by a dark more or less stellate line, the
cambium, frequently with 5-8 projecting angles, especially in the upper part of
the root.

Microscopical Characters
The outer cover, the metaderm, brown is formed of 1-4 irregular layers of
tabular polygonal suberized cells, with dark colored walls, about 170-220 µ long,
35-55 µ broad. Cortex, primary, is very narrow, consisting of pitted parenchyma
filled with starch granules. It shows occasional scattered isodiametric or slightly
elongated, thick walled pitted sclereids, more numerous in older roots. Endodermis
consists of brownish longitudinally elongated, rectangular cells with suberised radial
walls. Pericycle is formed of 1-3 or more and may be up to 20 layers of parenchyma

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