Ephedra

| Home | | Pharmacognosy |

Chapter: Pharmacognosy and Phytochemistry : Drugs Containing Alkaloids

Ephedra consists of the dried aerial parts of Ephedra gerardiana Wall, Ephedra sinica Stapf, Ephedra equisetina Bunge, Ephedra nebrodensis Tineo and other Ephedra species, belonging to family Ephadreaceae.


EPHEDRA

 

 

Synonyms

 

Ma Huang.

 

Biological Source

 

Ephedra consists of the dried aerial parts of Ephedra gerardiana Wall, Ephedra sinica Stapf, Ephedra equisetina Bunge, Ephedra nebrodensis Tineo and other Ephedra species, belonging to family Ephadreaceae.

 

Geographical Source

 

It is mainly found in China, India, Nepal, Turkey, Pakistan and Bhutan.

 

Cultivation and Collection

 

It is an evergreen shrub growing to 0.6 m by 2 m. The plant prefers light (sandy) and medium (loamy) soils and requires well-drained soil. The plant prefers acid, neutral and basic (alkaline) soils. It cannot grow in the shade. It requires dry or moist soil and can tolerate drought. Seeds are sown as soon as they are ripe in the autumn in a greenhouse. It can also be sown in spring in a greenhouse in sandy compost. Seedlings are transferred into individual pots as soon as they are large enough to handle and grown them for at least their first winter in a greenhouse.

 

Drug is collected in autumn since it contains maximum percentage of alkaloids. Green slender twigs are collected in autumn, dried and packed loose in bags. Sometimes the twigs are pressed tightly.

 

Characteristics

 

Ephedra gerardiana: It consists of cylindrical woody stem that is grey or greenish in colour. Nodes, internodes, scaly leaves and terminal buds are present in the stems. The distance between the internodes is 3–4 cm and the nodes bare the scaly leaves. They are bitter in taste. The plant has stamens and pistils on separate flowers; staminate flowers in catkins and a membraneous perianth, pistillate flowers terminal on axillary stalks, within a two-leaved involucre. Fruit has two carpels with a single seed in each and is a succulent cone, branches slender and erect, small leaves, scale-like, articulated and joined at the base into a sheath.

 

Ephedra sinica: Thickness of the stem is 4–7 mm branches are 1–2 mm. Length up to 30 cm of branches and 3–6 cm of internodes. The main stem is brown in colour. Leaves are 2–4 mm long, opposite, decussate and subulate. Leaf, base is reddish-brown, apex acute and recurved and lamina white in colour. A pair of sheathing leaves present at the nodes, encircling the stem and fused at the base,

 

Ephedra equisetina: Stems are woodier and more branched 1.5–2 mm. Length 25–200 cm of branches and 1–2.5 cm of internodes, outer surface is grey to pale green and smooth.

 

Ephedra nebrodensis: The stems are 15–35 cm in length; 1–2 mm thick, cylindrical, greenish-yellow in colour, nodes are brownish and distinct and fractured surface is fibrous in the cortex but pith contains brownish powdery mass. The leaves are brownish to whitish-brown in colour, scaly, connate, opposite and decussate, acute, agreeable and slightly aromatic odour and taste is astringent and bitter.

 

              Ephedra sinica


Microscopy

 

Transverse section of the stem shows epidermis, composed of thick-walled, quadrangular cells, covered by thick cuticle. Sunken stomata are present between many vertical ridges. Papillae are present in the ridges. Below the ridges, groups of nonlignified hypodermal fibres (nine to twenty per group) are present. Cortex is composed of chlorenchyma with outer zone of radially elongated cells and inner zone of spongy parenchyma. Cortex also contains few isolated fibres or groups of fibres (two to six per group), which are lignified. Pericycle is composed of groups of lignified fibres outside the phloem region. Vascular bundles are 6–10 in number, radially arranged in the cortex and composed of phloem and xylem. Pith is large with rounded cells, containing dark brown mucilaginous substance in pigment cells.

 


                 T.S. (schematic) of Ephedra herb



                   Transverse section of Ephedra herb


Chemical Constituents

 

Ephedra contains alkaloids Ephedrine (water-soluble salt of an alkaloid), Pseudoephedrine (analog of ephedrine), Norpseudoephedrine (An analog of ephedrine). The leaves and stems of ephedra also contain many potentially active compounds, such as tannins, saponin, flavone and volatile oils.

 


 

Chemical Test

 

To the drug (10 mg) in water (1 ml) dilute HCl (0.2 ml), copper sulphate solution (0.1 ml) and sodium hydroxide solution (2 ml) are added; the liquid turns violet. On adding solvent ether (2 ml) and shaking vigorously, the ethereal layer turns purple and the aqueous layer becomes blue.

 

Uses

 

Ephedrine is antiallergenic, antiasthmatic, antispasmodic, decongestant, cough suppressant, stimulant and vasoconstrictor. Pseudoephedrine is decongestant, cough suppressant and norpseudoephedrine is peripheral vasodilator used to treat angina. As a whole it is decongestant; it opens sinuses, increases sweating, dilates bronchioles (antiasthmatic use), diuretic, CNS stimulant, raises blood pressure, alleviates aches and rheumatism, alleviates hay fever/colds, etc.

 

Contact Us, Privacy Policy, Terms and Compliant, DMCA Policy and Compliant

TH 2019 - 2022 pharmacy180.com; Developed by Therithal info.