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Learn about the use of plants in treating respiratory problems like asthma and bronchitis. Discover the medicinal properties of Ephedra plant extracts such as ephedrine and their effectiveness in improving airway function. Find out more about plant-based solutions for enhancing respiratory health.
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Respiratory Problems • Various conditions can interfere with the gas exchange in the lungs • Infectious disease • Chronic diseases • Asthma • Emphysema
Asthma • Chronic breathing disorder • Characterized by inflammation of the airways, bronchial constriction, excessive mucous secretion - results in wheezing, coughing, and choking • Responsible for 5,000 deaths/yr in the US • Attacks triggered by exposure to allergens and also infections, stress, exercise
Airway constriction • Narrowing of airways due to • contraction of the smooth muscles • Inflammation/edema of bronchial walls • retention of viscid bronchial secretions
Asthma Increase • Close to 18 million people in US suffer from asthma including 5 million children (12 million under 16 yrs) • Over $11.3 billion in medical costs each year – including direct medical costs and lost productivity • Since 1980, asthma reports have increased 75% - up 160% in children • Increase especially seen in inner city – survey in south Bronx indicated that 28% of children had asthma symptoms • Exact reason not certain - possibly better diagnosis, possibly increased exposure to indoor allergens, outdoor pollutants, possibly lifestyle changes, lots of theories!
Asthma Treatment • Many treatment options • Bronchodilators • Anti-inflammatory drugs • Allergy shots (desensitization)
Bronchodilators • Help to stop asthma attacks after they've started • Can help prevent expected attacks, as from exercise • Relax smooth muscles of bronchioles - this opens bronchioles and makes breathing easier
Bronchodilators • What do they do • Adrenergic agents • Increase the volume and diameter of bronchial smooth muscles by relaxing them • Include norepinephrine, epinephrine, and ephedrine • Theophylline drugs • Act of the bronchial muscles to relieve obstruction, increase coronary blood flow and stimulate respiration
A very short list of plant extracts • Ephedrine • Theophylline
Ephedra Ephedrine and Pseudoephedrine
Ephedra spp. Gymnosperm in the Division Gnetophyta Ephedra sinica well known as source of drug ephedrine
Medicinal Use of Ephedra • Long history of use as a medicinal plant especially as a decongestant for asthma, bronchitis, and other respiratory conditions • In China, Ephedra sinica – called Ma Huang has been used for thousands of years • Also well known as a stimulant
Alkaloids in Ephedra • Ephedrine, pseudoephedrine, others • Ephedrine used in prescription drugs since the 1920s • Also used in OTC drugs • Very effective decongestants – relaxes bronchial muscles and opens airways • Also CNS stimulant that increases heart rate and blood pressure and blood flow to brain • Stimulating properties of pseudoephedrine not as great and preferred today
Ephedrine and Pseudoephedrine are stereo-isomers Ephedrine Pseudoephedrine
Mode of action • Mimic adrenal hormones – epinephrine and norepinephrine • Stimulates a and b-adrenergic receptors • b-2 receptors in the lungs are stimulated to open the airways - this is responsible for its effectiveness as a bronchodilator • Other receptors also stimulated: • b-1 receptors in the heart increase heart rate and force of contraction • a-1 receptors increase blood pressure and decrease circulation to the renal system and other parts of the body
Adrenal Hormones • Increased rate and force of contraction of the heart muscle: predominantly an effect of epinephrine acting through beta receptors • Constriction of blood vessels: norepinephrine, in particular, causes widespread vasoconstriction, resulting in increased resistance and blood pressure • Dilation of bronchioles: assists in pulmonary ventilation
More on adrenal hormones • Stimulation of lipolysis in fat cells: provides fatty acids for energy production in many tissues and aids in conservation of dwindling reserves of blood glucose. • Increased metabolic rate: oxygen consumption and heat production increase in response to epinephrine • Hormones also promote breakdown of glycogen in skeletal muscle to provide glucose for energy production
Epinephrine and Norepinephrine Synthesized in the body from a.a. Tyrosine
New b-2 agonists • Epinephrine (adrenaline) was once a conventional treatment for asthma • similar to ephedrine but much more active and short-acting • Epinephrine was replaced by current asthma medications which are able to act more selectively on b-2 receptors • Epinephrine still used in emergency treatment of asthma – Epi-pens
Common side effects of ephedrine • Headache, irritability, restlessness of muscles, nausea, sleeplessness, increased heart rate, urinary disturbances and vomiting • Higher dosages may result in drastic increases in blood pressure and cardiac rhythm disorders, heart palpitations • Since ephedrine chemically similar to epinephrine, it works like a powerful cardiac stimulant and may cause cardiac arrest in infants and heart patients
Ephedrine contra-indicated • Non-specific stimulation of adrenergic receptors means that Ephedra products should not be used in people with • anxiety and restlessness • high blood pressure • glaucoma • impaired circulation of the cerebrum • prostate adenoma
Ephedrine and pseudoephedrine uses • Originally Ephedra sinica • Synthesized in lab today • New synthetics available • Pseudoephedrine preferred • Many OTC • Herbal supplements – Ma Huang • Ephedrine abuse