Pharmacognosy

DEPARTMENT OF PHARMACOGNOSY AND BOTANY

Atropa belladonna

 

Botanical Origin.Atropa belladonna L. (Engl. Deadly Nightshade, Belladona; Ukr. ; Rus. , ). Family Solanaceae.

Parts Used.Folia Belladonnae, Herba Belladonnae, Radices Belladonnae. According to the EP, belladonna leaf consists of the dried leaf or of the dried leaf and flowering, and occasionally fruit-bearing, tops of Atropa belladonna L. Herba Belladonnae consists of the flowering or fruiting top with branches, Radix Belladonnae consists of the dried roots and rhizomes of Atropa belladonna L., Solanaceae.

Habitat.The plant is found throughout western, central and southern Europe, in the Balkans, southeast Asia, Iran, northern Africa, Denmark, Sweden and Ireland. It is cultivated in other countries, particularly England, France and the U.S.

Plant.Atropa belladonna is a perennial, herbacious plant 1 to 2 m high with a many-headed cylindrical rhizome. The woody stem is erect, branched, bluntly angular and hairy. The leaves are ovately pointed, entire-margined, downy and up to 15 cm long. The lower leaves are alternate. Near the inflorescence the leaves are in pairs of 1 large and 1 small. The flowers are solitary and hanging. The calyx is fused at the base, has 5 divisions and is spread like a star when the fruit ripens. The violet corolla is a campanulate tube, 2.5 to 3.5 cm long, dirty yellow on the inside with crimson veins. There are 5 stamens and 1 style with a 2-lobed stigma. The ovary is superior. The fruit is a cherrysized globose berry. The fruit is initially green, then becomes black and glossy with numerous black, ovoid seeds.

Fig. Atropa belladonna

MPM Description.The pubescence of the young leaves only remains near the veins in the older leaves. The secondary veins are at 60 and are anastomosed near the margin.

According to the EP, The leaves are green to brownish-green, slightly darker on the upper surface, often crumpled and rolled and partly matted together in the drug. The leaf is petiolate and the base of the lamina is acute and decurrent and the margin entire. The flowering stems are flattened and bear at each node a pair of leaves unequal in size, in the axils of which occur singly the flowers or occasionally fruits. The flowers have a gamosepalous calyx and campanulate corolla. The fruits are globular berries, green to brownish-black and surrounded by the persistent calyx with widely spread lobes.

Microscopical Characters.Transverse and surface sections of the leaves may be prepared by placing the dried material in a moist chamber for 24 hours before the sections are cut. The epidermis may be readily separated by gently warming small fragments in solution of chloral hydrate or 1 % sodium or potassium hydrate in a watch crystal for about 5 minutes, transferring to slide and exerting slight pressure on the cover slip with a rotary movement.


Fig. Atropa belladonna leaf in surface view. A Upper epidermis; Lower epidermis; B Epidermis over the veins. 1 Hair with a 1-celled stalk and a multi-cellular head; 2 glandular hair with a 2- to 4-celled stalk and a 1-celled head; 3 non glandular hair; 4 the cells with a dark masses of microcrystals of calcium oxalate

Both epidermises, as observed in vertical view, are composed of large wavy-walled epidermal cells with stomata and striated cuticle. Over the veins, however, the epidermal cells have rectilinear walls. There are a larger number of stomata on the lower than on the upper surface. Each stoma is surrounded by 3 or less often 4 neighboring cells, one of which is smaller than the rest. Non-glandular and glandular hairs occur as outgrowths from both epidermises. The former are thin-walled, uniseriate, of from 2 to 6 cells, occasionally showing terminal branching. The glandular hairs are of two kinds; one possesses a 2- to 4-celled stalk and a 1-celled head, the other a 1-celled stalk and a multi-cellular head.

The mesophyll between the epidermises exhibits a layer of short palisade cells directly beneath the upper epidermis and several layers of spongy parenchyma. Most of these cells contain chloroplastids but grayish-black cells may be observed scattered here and there. These are filled with sphenoidal microcrystals (crystal sand). The petiole, midrib and veins show bicollateral bundles. Palisade ratio: 5 to 7.

The stems are characterized by a circle of short bicollateral bundles, long, thin walled, slightly lignified pericyclic fibers, and cortical, ray and pith parenchyma possessing many cells containing microcrystals.

Fig. Powdered Belladonna Leaves, X 210. c, cr - Leaf parenchyma cells with dark masses of microcrystals; Co - collenchymatous cells from cortical tissues of midrib; el - lower epidermis with striated cuticle and stomata; en - epidermis over the veins with striated cuticle; es - upper epidermis with striated cuticle and occasional stomata; L leptome; me - branching cells of spongy parenchyma; nv - fragment of small vein; pa - palisade parenchyma cells in surface view; p'a' - palisade cells in longitudinal view; pg - glandular hairs, long and short, with unicellular and multicellular heads; St - stomata, surrounded by 3 or 4 cells, one of which is smaller than the others; tf - cortical tissues of the midrib; tr, v - tracheids and vessels

Powdered Drug.According to the EP, The dark green powder shows the following diagnostic characters: fragments of leaf lamina showing sinuous-walled epidermal cells, a striated cuticle and numerous stomata predominantly present on the lower epidermis (anisocytic and also some anomocytic); multicellular uniseriate covering trichomes with smooth cuticle, glandular trichomes with unicellular heads and multicellular, uniseriate stalks or with multicellular heads and unicellular stalks; parenchyma cells including rounded cells containing microsphenoidal crystals of calcium oxalate; annular and spirally thickened vessels. The powdered drug may also show the following: fibres and reticulately thickened vessels from the stems; subspherical pollen grains, 40 μm to 50 μm in diameter, with three germinal pores, three furrows and an extensively pitted exine; fragments of the corolla, with a papillose epidermis or bearing numerous covering or glandular trichomes of the types previously described; brownish-yellow seed fragments containing irregularly sclerified and pitted cells of the testa.

Constituents.The concentration of the total alkaloids in the leaf ranges from 0.3 to 0.6%. Hyoscyamine is by far the chief constituent (90%) and occurs alongside small quantities of scopolamine (2%) and their dehydration products (apoatropine and aposcopolamine). The other alkaloids are thought to be formed from hyoscyamine in the process of extraction. Flavonoids, tannins, hydroxycoumarins (scopoline, scopoletine), sterines also occur in the aerial parts.

According to the EP, it contains not less than 0.30 per cent of total alkaloids, calculated as hyoscyamine (Mr 289.4) with reference to the drug dried at 100 C to 105 C. The alkaloids consist mainly of hyoscyamine together with small quantities of hyoscine (scopolamine).

Belladonna roots yield tropan alkaloids: chief alkaloid hyoscyamine, in drying transformed to some extent during dehydration into atropine as well as apoatropine, 3-α-phenylacetoxytropane, tropine, cuskhygrine, scopolamine, pseudotropine.

Pharmacological Action. Uses.Atropa belladonna preparations act as a parasympatholytic or anticholinergic via a competitive antagonism of the neuromuscular transmitter acetylcholine. The root is used for arrhythmia, cardiac insufficiency NYHA I and II, nervous heart complaints, and colic-like pains in the gastrointestinal tract and bile ducts.

Approved by Commission E indications of its roots and herb include liver and gall bladder complaints. Belladonna leaf is used for spasms and colic-like pain in the gastrointestinal tract and bile ducts. External uses include gout and ulcers.

Belladonna yielding drugs are used as spasmolytics in the treatment of the gastrointestinal and biliary tracts disorders (Bellastesinum, Besalolum, Bellalginum, Becarbonum), cardioneuroses (Guttae Zelenini), insomnia, climacteric insanity (Bellasponum), due to pain-relieving action they are used for the treatment of hemmorhoids (Anusolum, Betiolum suppositoria).

Atropa belladonna