Minor common disorders of the respiratory system can often be successfully treated with phytotherapy and it can be helpful as a supportive measure in more serious diseases, such as bronchitis, emphysema, and pneumonia. For severe infections, antibiotic therapy may be needed and although, most antibiotics are natural products. However, for colds and flu-like virus infections, decongestants (e.g., menthol and eucalyptus), broncholytics, and expectorants (including ipecacuanha, thyme, and senega), demulcents (e.g. mallow), antibacterials and antivirals (e.g. elderflower, pelargonium), and immune system modulators (e.g. echinacea) are popular and effective.

1. Enas I. A. Mohamed

2. INTRODUCTION

3. Phytotherapy:
is a field of medicine that uses plants either
to treat disease or as health-promoting
agents.

4. RESPIRATORY TRACT DISORDERS

19. Strawberry tongue in streptococcal pharyngitis

39. 1. BRONCHODILATORS
A bronchodilator is a substance that:
 dilates the bronchi and bronchioles,
 decreasing resistance in the respiratory airway and
 increasing airflow to the lungs.
They are most useful in obstructive lung diseases, of
which asthma and chronic obstructive pulmonary
disease are the most common conditions.

40. BRONCHODILATORS
Ephedra
Origin: The dried aerial parts (or the entire plant) of
Ephedra sinica Stapf. (Fam. Ephedraceae).

41. BRONCHODILATORS

42. Clinical Uses
Decongestant
Bronchodilator

44. BRONCHODILATORS

46. BRONCHODILATORS
Irritability Tremors Headache
Nausea
Vomiting
Sleep disturbances
Contraindicated in
Heart conditions
Hypertension
Diabetes
Thyroid disease
BPH
Selectivity for -
over -adrenergic
receptors
Adverse Effects

47. BRONCHODILATORS

48. BRONCHODILATORS
2. Theophylline
Mechanism of action:
• Theophylline relaxes the smooth muscle of the bronchial airways
and pulmonary blood vessels
• Theophylline competitively inhibits phosphodiesterase (PDE), the
enzyme responsible for breaking down cyclic AMP in smooth muscle
cells, possibly resulting in bronchodilation.
• Theophylline also binds to the adenosine A2B receptor and
blocks adenosine mediated bronchoconstriction.

49. BRONCHODILATORS

52. 2- DECONGESTANTS
 Essential oil containing drugs are often used with
aromatic compounds (especially camphor) as chest rubs,
steam inhalations or nasal sprays, for their decongestant
properties.
 They are particularly useful for infants, children,
asthmatics and pregnant women for whom systemic
decongestants may not be appropriate.
 They may also be used orally, in pastilles, lozenges, or
cough sweets.
➢ Camphor
➢ Eucalyptus
➢ Menthol

53. DECONGESTANTS
A. Camphor
 Camphor is a pure natural product, derived from the Asian camphor tree (Cinnamomum camphora T. Nees &
Eberm., Lauraceae).
 Camphor has antiseptic, secretolytic and decongestant effects. Small doses were formerly taken internally for
colds, but it is now used only externally.
 Overdose causes vomiting, convulsions and palpitations, and can be fatal. However, when used externally in
therapeutic doses it is generally well tolerated

54. DECONGESTANTS
B. Eucalyptus oil
 The blue gum tree, Eucalyptus globulus Labill. and other
species (Myrtaceae) yield a highly characteristic oil which is
widely used as a decongestant and solvent.
▪ Constituents:
The oil contains 1,8-cineole (eucalyptol;) as the major component, with terpineol, α-pinene, p-cymene

55. DECONGESTANTS
B. Eucalyptus oil
 It may be taken internally in small doses (0.05–0.2 ml), as an ingredient of
cough mixtures, sweets and pastilles, or as an inhalation;
 It is applied externally in the form of a liniment, ointment or ‘vapour rub’.
 It is widely used in Menthol and Eucalyptus Inhalation BP for steam
inhalation as a decongestant.
▪ Adverse Effects:
Eucalyptus oil is irritant and, although safe as an inhalation, caution should be exercised when taken
internally as fatalities have been reported

56. DECONGESTANTS
C. Menthol
 Menthol is a monoterpene extracted from mint oils, Mentha spp. (especially M.
arvensis) or it can be made synthetically.
 Whole peppermint oil is used in herbal combinations to treat colds and
influenza (as well as for colic, etc;)
 Isolated menthol is an effective decongestant used in nasal sprays and inhalers.
 Menthol can be irritant and toxic in overdose but is generally well tolerated in
normal usage.

57. 3- ANTI-ALLERGIES
 Most antihistamines are synthetic in origin and,
although many flavonoids have anti-allergic properties,
they are nowhere near as potent as, for example,
cetirizine, desloratidine, fexofenadine or
chlorpheniramine.
 Recently, however, an extract of the herbal drug
Butterbur was found to be equivalent in activity to
cetirizine.
 There is a problem with toxic alkaloids in this plant,
which if present must be removed from the product;
thus it is not suitable as a home remedy without
expert advice.

58. ANTI-ALLERGIES
A. Butterbur, Petasites hybridus
 The root and herb of Petasites hybridus (syn. P. vulgaris, Tussilago
petasites, Compositae) are used.
 Active constituents:
 Sesquiterpene lactones, including a series of petasins and
isopetasins, neopetasin, petasalbin, furanopetasin petasinolides A
and B.
 Flavonoids including isoquercetin glycosides.
 Toxic pyrrolizidine alkaloids may be present, usually in higher
concentrations in the root

59. ANTI-ALLERGIES
A. Butterbur, Petasites hybridus
 The anti-inflammatory activity is due mainly to the petasin content. Extracts inhibit leukotriene synthesis
and are spasmolytic, and reduce allergic airway inflammation
 A recent randomized, double blind comparative study using 125 patients over 2 weeks of treatment
showed that butterbur extract is as potent as cetirizine.
Adverse Effects:
Internal use is not recommended unless the alkaloids are present in negligible amounts or have been
removed from preparations

60. ANTI-ALLERGIES

61. 4- EXPECTORANTS AND MUCOLYTICS
 The purpose of these drugs is to reduce the viscosity of mucus in the respiratory tract to enable
expectoration of phlegm in cases of chest and throat infection.
 Frequently, essential oils are used with expectorant aromatic compounds such as camphor.
 Many expectorants are included in cough mixtures and, although efficacy is difficult to demonstrate, these
products are very popular with patients in the absence of other treatments.
 All are used for coughs and colds, bronchitis and sinusitis, usually in conjunction with other decongestants,
demulcents, analgesics and, occasionally, antibiotics.
 Some of these drugs contain essential oils and salicylates (Thyme), and may also include the decongestants
mentioned above (eucalyptus, menthol); others contain saponins (e.g. senega, ivy, liquorice) oralkaloids
(Ipecacuanha).

62. 4- EXPECTORANTS AND MUCOLYTICS
A.Thyme
Consists of the dried leaves and flowering tops of Thymus
vulgaris 1. (Fam.Lamiaceae),
The plant has glandular hairs on the leaves and stems which
contain a volatile oil.
The main components of the oil are thymol and carvacrol, and
flavonoids,

63. 4- EXPECTORANTS AND MUCOLYTICS
A.Thyme
Thyme is stated to possess expectorant, mucolytic, antitussive and antispasmodic properties.
Such actions have been associated with the volatile oil and flavonoid constituents.
Thyme is used for the treatment of the symptoms of bronchitis and catarrh of the upper
respiratory tract.
Both thyme and thyme oil are ingredients of various proprietary drugs: syrups for the treatment
of respiratory disorders, antiseptic and healing ointments, preparations for inhalation.
Adverse effects:
- Thyme is reputed to affect the menstrual cycle and therefore high doses should not be ingested.
- The drug also possesses a low potential for sensitization.
Thyme oil is toxic: it should not be taken internally and only externally if opportunely

64. 4- EXPECTORANTS AND MUCOLYTICS
B. Senega (Snake root, rattlesnake root)
 Senega (snake root, rattlesnake root, Polygala senega L., Polygalaceae)
 The active constituents are triterpenoid saponins, the mixture
generally known as ‘senegin’. These are based on the aglycones
presenegenin, senegenin, hydroxysenegin, polygalacic acid and senegnic
acid.
 A French Patent claimed the fluid extract prepared with P.
senega could reduce the viscosity of phlegm in patients with
bronchiectasis. However, data on this clinical trial are limited. Overall,
the clinical evidence is Low.

65. 4- EXPECTORANTS AND MUCOLYTICS
B. Senega
 The saponins are irritant and haemolytic, but taken orally do not
appear to pose many problems.
 Nausea and vomiting are the most common side effects and, in
view of the other pharmacological actions,
 Care should be taken with senega when given in high doses or
to sensitive individuals.

66. 4- EXPECTORANTS AND MUCOLYTICS
C. English ivy
Consists of the dried leaves of Hedera helix L. (Fam. Araliaceae),
an evergreen climber plant.
The leaves contain saponins including hederasaponin B and C,
caffeic esters of quinic acid, flavonoids (rutin), alkaloids (emetine),
polyalcohols (falcarinol, falcarinone, II-dehydrofalcarinol),.
Ivy extract is spasmolytic in vitro and α-hederin seems the constituent responsible for the activity. Ivy
preparations are mostly used orally for the symptomatic treatment of cough and to treat acute benign
bronchial disease.
The frequent use of ivy-based products can cause allergic reactions and nausea.

67. 4- EXPECTORANTS AND MUCOLYTICS

68. 4- EXPECTORANTS AND MUCOLYTICS
D. Liquorice
 Consists or the dried roots and rhizomes of Glycyrrhiza glabra L.
(Fam. Fabaceae)
 Contains of glycyrrhizin, which is a mixture of the potassium and
calcium salt of glycyrrhizinic acid, a terpenoid saponin compound
which gives the drug its characteristic sweet taste (50 times
sweeter than sucrose).
 Liquorice is reported to be very useful as expectorant and
antitussive.
 It has been postulated that glycyrrhizin increases the bronchial
secretion and transport of mucus via a reflex pathway originating
in the stomach.

69. 4- EXPECTORANTS AND MUCOLYTICS
D. Liquorice
Adverse effects:
 Liquorice extract consumption can reduce blood potassium levels
resulting in abnormal heart rhythms, high blood pressure, oedema,
lethargy, heart failure and hypokalemic myopathy manifesting as flaccid
paralysis.
Drug interactions:
 With fludrocortisone due to mineralocorticoid effects
 With medicines that deplete potassium levels such as diuretics.
 Patients taking these medicines should avoid regular consumption of
liquorice.

70. 4- EXPECTORANTS AND MUCOLYTICS
E. Ipecacuanha
 It is obtained from the root and rhizome of Cephaelis ipecacuanha and
C. acuminata (Rubiaceae).
 Constituents: isoquinoline alkaloids. The most important are emetine
and cephaeline, with psychotrine.
 Ipecac extract is an ingredient of many cough preparations, both elixirs
and pastilles, because of its expectorant activity.
 Ipecac causes vomiting in large doses

71. 5- COUGH
Cough is a reflex triggered by mechanical or chemical stimulation
of the upper respiratory tract, or by central stimuli.
It is a protective mechanism that serves to expel foreign
bodies and unwanted material from the airways.
However, coughing is sometimes both useless and distressing
and can exhaust the patient psychologically and physically. Cough
suppression is then indicated

72. Drugs to suppress cough can reduce:
o local throat irritation (e.g. mucilaginous herbs)
o Peripheral suppression of the cough reflex (e.g. essential
oils)
o The sensitivity of the "cough center" (e.g. opiates).
5- COUGH

73. Phytotherapy of Cough
A. Demulcents and emollients:
are botanical drugs rich in mucilage traditionally used to relieve "dry"
coughs. The effect is due to formation of a protective coating that
shields the mucosal surface from irritants.
 Herbal drugs which proved clinically to have demulcent effect
- Elder flower and elder berry (Sambucus nigra).
- Marshmallow: (root of Althea officinalis L.)
5- COUGH

74. 5- COUGH
Elder flower and Elder berry
 Sambucus nigra, Fam.:Adoxaceae
 Constituents:
Triterpenes including urosilic and oleanic acids derivatives
Flavonoids as rutin and quercetin
Phenolic acids.
The flower contains essential oil
 Due to limited information on elder flowers, it should not be
administered during the pregnancy, and lactation without
medical supervision

75. 5- COUGH
Marshmallow
 root of Althea officinalis L.
 Constituents:
Root and leaves are rich in mucilage, flavonoids
 used internally for coughs and bronchial complaints

76. 5- COUGH
Phytotherapy of Cough
B. Cough suppressants:
(Codeine)
 is constituent of opium poppy (Papaverum somniferum) (Fam.: Papaveraceae)
 possess central antitussive actions by virtue of their agonist actions on opiate
receptors in the cough center.
 In large doses 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 countries

77. 5- COUGH
Phytotherapy of Cough
C. Plants with immunomodulant
 One possibly strategy to prevent or overcome respiratory infections is stimulation of the immune
system.
 Several herbs have been claimed to have such an effect, but their activity is quite different from that of
vaccines since herbal metabolites have no antigenic relationship to pathogens.
 Their effect is non-specific and relies on the stimulation of cellular immunity
 The most widely used herbal immunomodulant are:
• Echinacea species.
• Pelargonium

78. 5- COUGH
Phytotherapy of Cough
C. Plants with immunomodulant
Echinacea
• Echinacea angustifolia DC (narrow-leaf coneflower), Echinacea pallida (Nutt.) Nutt. (Pale coneflower),
and Echinacea purpurea (L.) Moench. (Purple coneflower). Fam.:Asteraceae.
Active constituents:
- Alkamides. Chemically, these compounds are usually isobutylamides or 2-methylbutylamides of
unsaturated fatty acids.
- Caffeic acid derivatives are also present; these are caffeic acid glycosides, or caffeic acid esters of quinic
acid (e.g., chlorogenic acid).

79. 5- COUGH
Phytotherapy of Cough
C. Plants with immunomodulant
Echinacea
•Immunomodulant, For the supportive treatment of the common cold. The therapy should start at the
first signs of the common cold.
- Adverse effects:
- Echinacea can cause minor side effects such as upset stomach, nausea, and dizziness. Serious side effects
include allergic reactions such as rash, swelling, and difficulty breathing. It can also worsen asthma
symptoms

80. 5- COUGH
Phytotherapy of Cough
C. Plants with immunomodulant
Pelargonium
 Roots of Pelargonium sidoides Fam. Geraniaceae.
 The most characteristic compounds in Pelargonium roots are the
polyhydroxylated coumarins (e.g. umckalin and artelin).
 the immunomodulatory effect of the extracts may be related to the
macrophage activating activity.

81. END OF LECTURE
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