Synonyms:- Digitalis leaves, Foxgloves leaves.
Biological Source:- Digitalis consists of dried leaves of Digitalis purpurea (Scrophulariaceae), dried at a temperature below 60°C, immediately after collecting the leaves. The leaves should contain not more than 5% of moisture.
Cultivation and Collection:- It is biennial or perennial herb of regarding one to two metres tall. It’s cultivated in geographic region (Tannary and Kishtawar) and additionally in Mungapoo and Nilgin hills. it’s propagated by seeds of elite strain, containing high glycosidal content. It desires calcarious, sandy, light-weight soil with traces of metal. The soll is sterilised by steam before sowing It grows fitly in sandy scenario, luxuriantly at AN altitude of 1600 to 3000 m. The seeds of digitalis ar terribly little in size in one hundred seeds weigh forty one seventy mg. {they ar|they’re} mixed with fine sand and planted within the nursery beds in March/April regarding twenty five metric weight unit seeds are required per area unit. The young seedlings ar transplanted in Sept and November. The crop is manured properly and unbroken freed from weeds. The plantation is completed doubly a year. within the 1st year, the plant bears rosette leaves and within the second year sessile leaves. The plant flowers in month of April and is followed by mature. If the plants ar to be allowed to grow, the flowering A-one ar removed. Crop is protected against plant diseases, that otherwise result in loss of efficiency of the drug.
Microscope Character:- Digitalis is a dorsiventral leaf. It has anomocytic stomata on both surfaces and water pores at the apex of most of the marginal teeth. The trichomes are uniseriate multicellular (3 to 5 cells) and bluntly pointed. There are glandular trichomes also with unicellular stalk and unicellular or bicellular head. The glandular trichomes are generally located over the veins. Collapsed celled covering trichomes are one of the important characteristics of digitalis. Digitalis is free of calcium oxalate and sclerenchyma. Starch grains are present in the endodermis. There is collenchyma at three different places le at the upper epidermis, lower epidermis, and pericyclic part, which is also characteristic of digitalis.
Chemical Constituents:-
Important contributions to studies pertaining to chemical composition of the drug were made by Nativelle (1868), Killiani (1891) and Stoll (1938).
Digitalis contains 0.2 to 0.45 % mixture of cardiac glycosides (cardenalides). purpurea glycosides A and B, which are primary glycosides. In addition, digitalis also contains several other glycosides such as odoroside H, glucogitaloxin, gitaloxin, veradoxin, and glucoverodoxin. The products of hydrolysis of purpurea glycoside A and purpurea glycoside B, the chief active constituents of the drug, are as under.
Uses:- Digitalis increases excitability of cardiac muscles and produces more powerfulcontractions. It is effective in congestive cardiac failure to increase cardiac output and to relieve venous congestion. Hence, it is described as a cardiac tonic. The improvement of circulation through kidney results in diuresis and loss of oedema. The major disadvantage of digitalis is that it has cumulative effect and therefore, in prolonged treatment one has to watch the patient carefully.
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