lecture 1 - herbs.pdf

Pharmacognosy II PG 303 Herbs Assoc. Prof. Noha Khalil 1 What’s meant by medicinal HERB? A drug composed of tender parts of plant axis, leaves, flowers & fruits It maybe: Part of aerial shoot, usually the tops, as in Cannabis Whole aerial par...

Pharmacognosy II PG 303 Herbs Assoc. Prof. Noha Khalil 1 What’s meant by medicinal HERB? A drug composed of tender parts of plant axis, leaves, flowers & fruits It maybe: Part of aerial shoot, usually the tops, as in Cannabis Whole aerial parts , as in Lobelia Whole plant including roots Whole undifferentiated plant body or thallus of lower plants {Thallophyta} (plants don`t have well differentiated body design): Ergot & fucus 2  Some Herbs of Medicinal Importance Herbs containing Alkaloids Herbs containing Herbs containing Volatile Oil Lobelia Resin Hyoscyamus Ergot Mentha Ephedra Cannabis Vinca Thyme Passiflora 3 http://cdn2-b.examiner.com/sites/default/files/styles/image_content_width/hash/4f/9f/4f9f83838c0a176c56a2723d6b48c604.jpg?itok=aub2GB91 Herbs containing Volatile oil 4  Mentha Thyme Dried leaves & flowering tops Dried aerial parts of Thymus of Mentha piperita vulgaris & other Thymus species Family: Labiatae (Lamiaceae) Odor: Aromatic, characteristic Taste: aromatic followed by a cold Taste: aromatic pungent sensation. 5  Main Active Constituents Mentha Thyme ❑ Volatile oil: containing ❑ Volatile oil: containing phenolic compounds: ✓ Menthol (Alcohol) ✓ Thymol ✓ Menthone ✓ Carvacrol ✓ Menthyl Acetate ❑ Tannins ❑ Tannins ❑ Flavonoids ❑ Flavonoids ❑ Gums ❑ Resins 6 Microscopical characters of powdered plant Mentha Thyme Diacytic stomata Glandular hair: (Labiaceous &Capitate) Non- glandular hair: Non-glandular hair (multicellular uniserriate) (Unicellular conical & bent hair) 7  http://www.mdpi.com/molecules/molecules-19-18781/article_deploy Mentha powder Non- glandular hair Capitate hair Labiaceous hair Diacytic stoma Labiaceous hair 8  Labiaceous glandular trichome Thyme powder Non-glandular Bent hair 9  Medicinal Uses Mentha Thyme GIT: GIT: 1. Carminative 1. Carminative 2. Digestive 2. Digestive 3. Anti-spasmodic 3. Anti-spasmodic 4. Antimicrobial 4. Anthelmintic 5. Anti-emetic 5. Antimicrobial 6. Promote liver and gall bladder function (choloretic & cholagogue) Respiratory tract: Respiratory tract: 1. Decongestant Used in whooping cough and bronchitis as 1. Expectorant 2. Secretolytic 3. Disinfectant in inhalations Externally: 1. Local anaesthetic 2. Anti-pruritic 3. Anti-parasitic 10 N.B.: The oils are administered in the form of enteric coated capsules.  Chemical Tests Mentha Thyme Micro-chemical tests: Positive with Sudan lll. Special chemical test: Menthol crystals + few drops Thymol crystals + 1ml of Conc. H2SO4 + few drops glacial acetic acid + few Of vanillin / H2SO4 → orange yellow drops color + H2O → violet color conc. H2SO4 + 1 drop of HNO3 → a deep bluish green color is developed. 11  Contraindications & Drug Interactions Mentha Thyme Contraindications Contraindications 1. GERD (gastro-esophogeal reflux disease) 1. Thymol at high doses may causes liver toxicity, 2. Infants and small children albuminuria and hematuria. 3. May worsen gall stones 2. Concentrated forms of thyme are contraindicate din 4. Pure menthol is poisonous and should not be taken pregnancy as it may cause uterine contractions. orally 5. Excessive mentha oil on the skin may cause allergic Drug Interactions reactions (skin rash) 1. Thyme interact with anti-coagulants and may increase risk 6. Never used on broken or irritated skin or near the eyes of bleeding. and mucous membrane. 2. Thyme interact with anti-hyperglycemic drugs and may cause severe hypoglycemia. 3. Thyme interact with sedatives and CNS depressants and may cause drowsiness. 12 Mentha Thyme Some pharmaceutical dosage forms in the Egyptian market 14