Medicinal Herbs: Lecture 2 Alkaloids

• Medicinal Herbs Lecture 2 covers herbs containing alkaloids.
• The lecture includes Solanaceous herbs, Vinca (Periwinkle), and Ephedra (Ma-Huang).

Solanaceous Herbs

• Solanaceous herbs listed under E.P 1984 Definitions include Stramonium, Belladonna, and Hyoscyamus (Egyptian henbane).
• Solanaceous Herbs contain Tropane alkaloids.
• Tropane alkaloids are molecules containing a substituted tropane ring in their structure.
• A hallucinogen is a psychoactive agent likely causing hallucinations, perceptual anomalies, and changes in thoughts, emotion, and consciousness.
• Atropine sulfate can treat organophosphorus poisoning and lowers saliva secretions during surgery.
• Atropine can treat muscle spasms of the GI tract, gallbladder, urinary system, and Irritable Bowel Syndrome.
• Atropine can enlarge the pupil for eye examinations, facilitate medical procedures, and help treat asthma via nebulization.
• Should be used with caution in patients with coronary heart disease or hypertension, as it can worsen tachycardia or hypertension.
• Hyoscine is an antimuscarinic drug also known as scopolamine.
• Hyoscine butylbromide reduces intestinal motility and relieves gastrointestinal smooth muscle spasms.

Vinca (Periwinkle)

• Vinca is in the family apocynaceae.
• Vinca includes Madagascar Periwinkle (Vinca rosea L., Catharanthus roseus G. Don.) and Lesser Periwinkle (Vinca minor L.).
• Vincamine, an alkaloid isolated from Vinca minor, increases cerebral circulation and oxygen utilization, which can treat cerebral disorders in geriatrics.
• All parts of the Madagascar Periwinkle contain alkaloids, specifically dimeric alkaloids of the indole indoline group.
• Vinblastine and vincristine treat cancer.
• Vinblastine is used for Hodgkin's disease and non-Hodgkin's lymphomas.
• Vincristine is used mainly for acute lymphocytic leukemia treatment, which is superior as an antitumor, even though it is more neurotoxic.
• Vinorelbine is a newer, orally active, semi-synthetic derivative with broader anticancer activity and lower neurotoxic side effects

Ephedra (Ma-Huang)

• It consists of the dried young twigs of Ephedra sinica and E. equisetina, among others in the family Ephedraceae (Gnetaceae).
• Ephedra is a Gymnosperm.
• Angiosperms are flowering plants with seeds enclosed in an ovary, while gymnosperms, non-flowering plants, have unenclosed seeds.
• The reproductive system of gymnosperms is called cones.
• The herb contains 0.5–2.5% alkaloids of the phenyl alkyl amine group, mostly l-ephedrine (30-90%), d-pseudo-ephedrine, l-nor-ephedrine, and d-nor-pseudo-ephedrine.
• Ephedra alkaloids are adrenergic or sympathomimetic drugs.
• Ephedrine stimulates the central nervous system, increases blood pressure, causes tachycardia, acts as a bronchodilator and cough sedative, and increases blood sugar levels.
• Ephedra alkaloids and salts like ephedrine and pseudoephedrine are FDA-approved for common cold, flu, and allergies as nasal decongestants and vasopressors.
• Ephedra stimulates thermogenesis in adipocytes, causing weight loss and enhancing athletic performance.
• The FDA recommends a maximum of 24 mg of ephedrine daily for up to 7 days.
• Typical doses for weight loss can cause toxicity and addiction with regular use of 50-100mg 3x daily.
• In 2004, the FDA banned caffeine and ephedra combinations for uses outside of allergies, colds, and asthma.
• It has also been banned by many sports organizations for being a performance-enhancing supplement.