Natural products have proven

effective for the treatment of

Respiratory diseases.

(1) EXPECTORANTS:

(a) Thymus vulgaris.

Drug name: Thymi Herba

Plant source: Thymus vulgaris

Other names: Thyme

Family: Lamiaceae

Constituents:

(a) Flavonoids:

Thymonine

Thymusine

Apigenin

Salvigenin

Naringenin

Luteolin

(b)Volatile oils

(c)Triterpenes

Effects:

Bronchial antispasmodic, expectorant

Indications and uses:

Cough and bronchitis

Precautions and adverse reactions: No health hazards with

therapeutic doses. The oil may have a weak potential for

sensitization.

(b) Licorice

Plant name: Glycyrrhiza glabra

Other names: Licorice

Family: Fabaceae

Constituents:

1. Triterpene saponins: chief compounds:

• Glycyrrhetic acid (sweet tasting aglycone 18-β- glycyrrhetic acid, salts termed glycyrrhizin).

• 18-α- glycyrrhetic acid.

• Glycyrrhetic acid methyl ester

• Glabric acid

2. Flavonoids including:

• Liquiritigenin

• Isoliquiritigenin

3. Hydroxycoumarins, steroids and volatile oils.

Effects:

• Anti-inflammatory/ anti-platelet effects.

• Antiulcer effects

• Antiviral/ antifungal effects

• Mineralocorticoid effects

Indications/ uses:

• Cough/ bronchitis

• Gastritis

Contraindications: chronic hepatitis, cirrhosis of the liver,

severe liver insufficiency, diabetes, arrhythmias, hypertension,

hypertonia, hypokalemia, smoking and pregnancy.

Precautions and adverse reactions:

• Prolonged intake of herb may result in hypokalemia, hypernatremia, edema, hypertension and cardiac complains (resulting from mineralocorticoid effect as it inhibits transformation of cortisol into cortisone).

• Glycyrrhetic acid causes inhibition of peripheral metabolism of cortisol and produces a pseudo-aldosterone-like effect.

• Retention of sodium and water and suppression of the renine-aldosterone system was associated with extracts of the root.

• Hypokalemic rhabdomyolysis resulting in acute renal failure was reported with glycyrrhizin use.

Drug interaction:

• Furosemide/Thiazide diuretics due to the additive effect of hypokalemia.

• Digitalis glycosides as hypokalemia produced by licorice may potentiate digitalis toxicity.

• Anti-arrhythmic agents (procainamide, quinidine) as they may potentiate hypokalemia and severe ventricular tachycardia reported with licorice consumption.

• Corticosteroids

(c) Ipecac

Drug name: Ipececuanha

Plant source : It consists of the dried roots and rhizomes of Cephaelis

ipecacuanha and Cephaelis acuminata

Family: Rubiaceae .

Constituents: Isoquinoline alkaloids mainly:

Emetine, cephaline and psychotrine.

Indications and uses:

Ipecac extract is an ingredient of many cough preparations, both elixirs and pastilles, because of its expectorant activity. Ipecac liquid extract BP is given at a dose of 0.25-1 ml.

(2) ANTITUSSIVES:

(a) Opium (Codeine)

Plant source: Papaver somniferum

Family: Papaveraceae

Constituents:

The most important type of alkaloid is morphine type:

• Morphine

• Codeine

• Thebaine

Indication and Uses:

• It has antitussive activity with slight depression of the

cough centers.

• It causes slight bronchoconstriction due to direct

effect on smooth muscles, decrease in secretions and

release of histamine.

Dose: Formulated as linctus at a dose of 5-10 mg 4

hourly to treat cough.

Precautions and adverse reactions: Codeine is sedating

and constipating. In large dose it may cause respiratory

depression and should not be used in hepatic or renal

impairment. It is also liable to abuse and is available only

on prescription in many country.

(3) BRONCHODILATORS

(a) Ephedra:

Drug name: Ephedra

Plant name: Ephedra sinica, Ephedra equisetina, Ephedra

intermedia, Ephedra gerardiana

Family: Ephedraceae

Constituents:

Alkaloids mainly: ephedrine, pseudoephedrine, norephedrine,

norpseudoephedrine. Flavonoids and proanthocyanidins.

Indication and Uses

It accelerates respiration and increases its intensity, it is

bronchodilator.

Ephedrine HCl has a vasoconstrictive effect and used in nasal

drops and sprays for rhinitis, sinusitis, rhino pharyngitis and

nasal congestion. It is also incorporated in preparations for non-

productive cough and acute attacks of asthma.

(b) Camphor

Drug name: Camphora

Plant source: Cinnamomum camphora

Other name: Gum camphor, Laurel camphor

Family: Lauraceae

Constituents:

It is a single substance: D (+)-camphor. L(-)-camphor also occurs in nature. Synthetic camphor is DL-camphor

Effects: Bronchial secretolytic and bronchospasmolytic

Indications and uses

Cough and bronchitis

Precautions and adverse reactions:

Local administration can lead to skin irritation, contact eczema,

resorbent or air-borne poisoning. The drug is sometimes used as

hashish substitute.

Contraindications: The drug is contraindicated in pregnancy or

by infants.

Overdosage: Symptoms of poisoning include delirium, spasms and

respiratory disturbances. Treatment proceeds symptomatically.

(c) Eucalyptus

Drug name: Eucalypti Folium

Plant source: Eucalyptus globulus

Other name: Eucalyptus, blue gum, Fever tree leaves

Family: Myrtacea

Constituents:

Eucalyptus oil:

Chief constituent is 1, 8 cineol

Eucalyptus leaf:

1. Volatile oil: Chief constituent is

2. 1, 8 cineol

2. Flavonoids

Effects:

Eucalyptus oil: Expectorant, cough relieving, inhibits prostaglandin

biosynthesis, antibacterial, fungicidal and mild antispasmodic.

Eucalyptus leaf: Expectorant, anti-inflammatory and mild

antispasmodic.

Indications and uses:

Eucalyptus oil:

Cough and bronchitis

Rheumatism

Eucalyptus leaf:

Cough and bronchitis

Precautions and adverse reactions: For both oil and leaf

• The administration of the drug in rare cases leads to nausea, vomiting and diarrhea.

• It should not be given internally with inflammation of the gastrointestinal atria and the biliary duct with severe illness of the liver.

• Pediatric use: when infants and small children apply preparations containing the oil to their faces, they may suffer from bronchial spasms, asthma-like attacks or even death by asphyxiation.

Over dosage:

• Overdoses can lead to life-threatening poisoning. Severe poisoning is possible for children after few drops and in adults with 4 to 5 ml.

• Symptoms include drop in blood pressure, circulatory disorders, collapse and asphyxiation.

• Symptoms are treated with activated charcoal administration followed by therapy composed of diazepam for spasms, atropine for colic, electrolyte replenishment and sodium bicarbonate infusions for any acidosis. oxygen respiration may also be necessary.

(d) Tea

Plant source: Camellia sinensis

Other name: Cháhuā,

Family: Theaceae.

Constituents: Fresh leaves contains

22.2% polyphenols, 17.2% protein, 4.3% caffeine and theophylline.

Indications and usage:

Cough and bronchitis.

Precautions and adverse reactions:

The condensed catechin tannin of tea is linked to high rates of

esophageal cancer in some areas where tea is heavily consumed.

This effect apparently may be overcome by adding milk which

binds the tannin preventing its deleterious effects.

• The plants are frequently aromatic in all parts and include many widely used culinary herbs, such as basil, mint, rosemary, sage, savory, marjoram, oregano, hyssop, thyme, lavender, and perilla. Some are shrubs, trees (such as teak), or, rarely, vines. Many members of the family are widely cultivated

• Flavonoids (or bioflavonoids) (from the Latin word flavus meaning yellow, their color in nature) are a class of plant secondary metabolites. Flavonoids were referred to as Vitamin P [1] (probably because of the effect they had on the permeability of vascular capillaries) from the mid-1930s to early 50s, but the term has since fallen out of use.[2]

• Chemically, they have the general structure of a 15-carbon skeleton, which consists of two phenyl rings (A and B) and heterocyclic ring (C). This carbon structure can be abbreviated C6-C3-C6. According to the IUPAC nomenclature,[

• Flavonoids have been shown to have a wide range of biological and pharmacological activities in in vitro studies. Examples include anti-allergic, anti-inflammatory, antioxidant, anti-microbial (antibacterial, antifungal, and antiviral), anti-cancer, and anti-diarrheal activities. Flavonoids have also been shown to inhibit topoisomerase enzymes

• Essential oils are non water-based phytochemicals made up of volatile aromatic compounds

• Triterpenes are terpenes consisting of six isoprene units and have the molecular formula C30H48. The pentacyclic triterpenes can be classified into lupane, oleanane or ursane groups.[1] A notable pentacyclic triterpene is Boswellic acid.

• Proanthocyanidins are a class of polyphenols

found in a variety of plants. Chemically, they

are oligomeric flavonoids. Many are are

oligomers of catechin and epicatechin and

their gallic acid esters. More complex

polyphenols, having the same polymeric

building block, form the group of tannins