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.
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.
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.
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