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Deadly Cures:
Medical discoveries from poisonous plants
Cassandra L. Quave, Ph.D.
Assistant Professor
Department of Dermat...
Virtue itself turns to vice, being misapplied,
And vice sometimes by action dignified.
Within the infant rind of this smal...
Outline
• Medical Ethnobotany
• Why do plants make poisons?
• Poison… or food?
• Poisons in history, legend and myth
• Med...
The Science of Ethnobotany
• Ethnobotany (from
ethnology, study of
culture, and botany, study
of plants) is the scientific...
Ethnobotany is Multidisciplinary
Ethnobotany
Botany
Chemistry
Microbiology
Anthropology
Linguistics
Pharmacology
• Medicin...
Deter other
plant
species
from
growing
nearby
Fight off
microbial
invasion &
infection
Attract pollinatorsDefense against
...
Poisons in Human History
• Early humans likely
experienced much poisoning
in the search for new foods
• One function of ea...
Cassava: Sweet and Bitter Manioc
• Manihot esculenta Crantz,
Euphorbiaceae
▫ Starchy tuber is the main source
of carbohydr...
Poke Weed…
Poison, Medicine or Food?
• Phytolacca americana L., Phytolaccaceae
Young plant (young leaves only) eaten as
“p...
Poisonous Gymnosperms
• All cycads and zamias have poisonous fleshy seeds
▫ BUT… if the azoxy alkaloids are washed out, th...
Poisons and the Criminal Arts
• Agrippina (19-59 AD)
▫ Empress and wife of Emperor
Claudius and mother of Nero
▫ Used pois...
The execution of Socrates – Plato’s account
Socrates walked about, and presently, saying that his legs
were heavy, lay dow...
Poison Hemlock
Conium maculatum L., Apiaceae
• European poison hemlock
made famous by Socrates’
execution (contains toxic
...
Medicine or Poison?
The distinction between poison and medicine often
comes down to two simple points: dose and intent.
“N...
Poisons and the criminal arts
• Cleopatra (51-30 BC)
• Tested poisons on her
slaves
▫ Henbane
 Hyoscyamus niger L.,
Solan...
Deadly Nightshade
Atropa belladonna L., Solanaceae
• It was used in traditional treatments
for centuries for an assortment...
Deadly Nightshade
Atropa belladonna L., Solanaceae
• Toxicity
▫ Berries are attractive & taste sweet, but
consumption can ...
Deadly Nightshade
Atropa belladonna L., Solanaceae
• Source of atropine
▫ Useful in management of
bradycardia following a ...
Poison nut
Strychnos nux-vomica L., Loganiaceae
• Active Compound:
▫ Indole alkaloids (strychnine
and brucine) from dried ...
Henbane
Hyoscyamus niger L., Solanaceae
• Traditionally used in combination
with Atropa belladonna and Datura
spp. for pys...
Jimsonweed
Datura stramonium L., Solanaceae
• Used as recreational
psychoactive drug – users often
unaware of toxicity/poi...
Scopolamine (aka Hyoscine)
• Medicinal applications:
▫ Remedy for motion sickness
 Oral dose or by patch
▫ Postoperative ...
Hyoscyamine
• Medicinal uses:
▫ Treatment of certain GI disorders
(peptic ulcers, irritable bowel
syndrome, colic) and con...
Calabar bean
Physostigma venenosum Balf. f., Fabaceae
• Calabar bean
▫ Historical ‘ordeal’ bean in the Calabar area
of Nig...
Poisons in Mythology
• Plant teratogen causes Cyclopia!
• Veratrum album L., V. californicum
Durand and V. viride Aiton,
M...
False Hellebore/ White
Hellebore
Veratrum album L.,
Melanthiaceae
Hellebore/ Black Hellebore
Helleborus niger L.
Ranuncula...
Groundsels; Ragworts
Senecio spp., Asteraceae
• Mistaken identity – confused
with a Gnaphalium spp.&
included in herbal re...
Oleander
Nerium oleander L., Apocynaceae
• Examples of poisoning
events:
▫ Ingestion after confusion
with eucalyptus
▫ Ing...
Ginkgo: Poison or Medicine? Both?
• Ginkgo biloba L., Ginkgoaceae
• Leaves used in herbal supplements for improved cogniti...
Autumn crocus; Meadow saffron
Colchicum autumnale L., Colchicaceae
• Colchicine derived from this
plant used medicinally t...
Colchicine
• 1st isolated in 1820
• Used as alternative gout treatment for those
unable to tolerate NSAIDs
• How it works:...
Draining of dropsical fluid, 1741 Digitalis purpurea L.
Common Foxglove
Foxglove
Digitalis purpurea L., Plantaginaceae
• 1700’s British folk medicine
• William Withering published book in
1785 b...
Pacific Yew
Taxus brevifolia Nutt., Taxaceae
• History of use in Native American traditional
medicine: respiratory, dermat...
• One BIG problem – very low
yield in plant (0.004%)
▫ Solution: semi-synthesis of taxol by
conversion of metabolites avai...
Docetaxel (Taxotere®)
• Semi-synthetic analogue of
paclitaxel
• Anti-mitotic chemotherapy
(interferes with cell division)
...
Mayapple; American Mandrake
Podophyllum peltatum L., Berberidaceae
• Long history of traditional use of
rhizomes as medici...
Etoposide
• Marketed as VePesid®
▫ Small cell lung cancer, testicular cancer &
lymphomas
• antineoplastic or cytotoxic che...
Teniposide
• Teniposide marketed as Vumon®
 brain tumors, childhood acute leukemia
• Administered by injection
• Semisynt...
(+)-Tubocurarine
Dart Poisons
The varzea
Dart Poisons
• Neuromuscular blocking agents
▫ Isoquinoline & indole alkaloids
▫ (+)-tubocurarine leading agent
▫ Competes...
Curare vine
Chondrodendron tomentosum Ruiz & Pav., Menispermiaceae
• (+)-Tubocurarine
▫ Skeletal muscle relaxant
▫ Helped ...
Useful poisonous plants in the Mediterranean
Pantelleria
Basket weaving for Agricultural & Fishing Tools
Euphorbiaceae
Daphne gnidium L., Thymelaeaceae
Ethnobotanicals uses:
• Insect repellent (ticks and
fleas)
• Hemostatic
Daphne gnidium poisoning
• Leaves are the most toxic
• Symptoms include:
▫ Headache
▫ Shivering
▫ Paleness
▫ Pupil dilatat...
Castor bean
Ricinus communis L., Euphorbiaceae
• Castor oil extracted from seeds is
used medicinally as laxative – but
eat...
Poisonous plants in the home and yard
Calcium oxalate is found in many
house plants
• Symptoms of poisoning:
▫ Dermatitis
▫ Swelling of the tongue,
can lead to ...
Poisonous house plants from the
Araceae family contain calcium oxalate
Philodendron
Philodendron spp.
Dumbcane
Dieffenbach...
Abrus precatorius L., Fabaceae (rosary pea;
jequirity bean)
• Toxic effect from chewing the seeds
• Active Compound:
▫ Abr...
Rhus Dermatitis
• Rhus = group of plants responsible for more cases of Allergic
Contact Dermatitis (ACD) than any other al...
Rhus Dermatitis Plants
• Anacardiaceae
▫ Toxicodendron radicans (L.) Kuntze
[Poison Ivy]
▫ Toxicodendron diversilobum (Tor...
Rhus Dermatitis Plants
• Anacardiaceae
▫ Toxicodendron vernicifluum
(Stokes) F.A. Barkley [Lacquer Tree]
▫ Anacardium occi...
Conclusions
• There are many
poisonous plants that
actually serve an
important role to many in
terms of:
▫ Food security
▫...
Acknowledgements
• Emory University Herbarium
Staff and Volunteers
• Philanthropic donation
• How to help the Emory
Herbar...
Fernbank Museum Lecture: Deadly cures - 2015
Fernbank Museum Lecture: Deadly cures - 2015
Fernbank Museum Lecture: Deadly cures - 2015
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Fernbank Museum Lecture: Deadly cures - 2015

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In March 2015, Dr. Quave presented: "Deadly Cures: Medical Discoveries from Poisonous Plants" as a ticketed public lecture at Fernbank Museum in Atlanta, GA as part of their special exhibit "The Power of Poison". In this talk, she discussed the reasons why plants produce poisonous compounds and the myriad ways that humans have used these chemicals for both health and harm.

Abstract:
Plants produce a fascinating mixture of biologically active compounds for the purposes of defense against threats in their environment. Over time, mankind has discovered ingenious ways to transform and make use of plant poisons ranging from applications in agriculture, fishing, hunting, and traditional medicine. Oftentimes, the distinction between poison and medicine comes down to two simple points: dose and intent. In this lecture, Dr. Quave will discuss how the scientific study of poisonous plants has led to the discovery of some of the leading pharmaceutical drugs in use today.

A full review of the talk is available here: http://www.destinationhealtheu.org/healthemory/an-overview-of-dr-cassandra-quaves-lecture-on-medicinal-and-poisonous-plants-at-fernbank

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Fernbank Museum Lecture: Deadly cures - 2015

  1. 1. Deadly Cures: Medical discoveries from poisonous plants Cassandra L. Quave, Ph.D. Assistant Professor Department of Dermatology (SOM) Center for the Study of Human Health (ECAS) Curator Emory University Herbarium E-mail: cquave@emory.edu Website: http://etnobotanica.us/ Twitter: @QuaveEthnobot Deadly Nightshade
  2. 2. Virtue itself turns to vice, being misapplied, And vice sometimes by action dignified. Within the infant rind of this small flower, Poison hath residence, and medicine power. -William Shakespeare, Romeo and Juliet
  3. 3. Outline • Medical Ethnobotany • Why do plants make poisons? • Poison… or food? • Poisons in history, legend and myth • Medical discoveries from poisonous plants • Poisonous plants in the home and yard
  4. 4. The Science of Ethnobotany • Ethnobotany (from ethnology, study of culture, and botany, study of plants) is the scientific study of the relationships that exist between peoples and plants. • Ethnobotany is the science of survival.
  5. 5. Ethnobotany is Multidisciplinary Ethnobotany Botany Chemistry Microbiology Anthropology Linguistics Pharmacology • Medicine • Conservation • Food security
  6. 6. Deter other plant species from growing nearby Fight off microbial invasion & infection Attract pollinatorsDefense against herbivory Why do plants make poisons?
  7. 7. Poisons in Human History • Early humans likely experienced much poisoning in the search for new foods • One function of early agriculture was to select for more palatable (less bitter, less poisonous) plant variants • Food processing to remove poison also important Cassava
  8. 8. Cassava: Sweet and Bitter Manioc • Manihot esculenta Crantz, Euphorbiaceae ▫ Starchy tuber is the main source of carbohydrates in the tropics ▫ Tuber is filled with poisonous cyanogenic glycosides and hydrogen cyanide (HCN)  A dose 40 mg of pure cassava cyanogenic glycoside is sufficient to kill a cow. ▫ Tuber is processed to remove the poison (soaking, boiling, fermentation) Drinking masato – fermented cassava beverage. Peruvian Amazon
  9. 9. Poke Weed… Poison, Medicine or Food? • Phytolacca americana L., Phytolaccaceae Young plant (young leaves only) eaten as “poke salet” • Contains phytoagglutinins (pokeweed mitogens), but can be denatured with processing (heat labile) ▫ Boiled in water, water tossed several times (thrice boiled) • Used in Native American traditional remedies for ulcer, rheumatism, kidney problems • Mature plants (esp. roots) are highly toxic if consumed. • Symptoms include: ▫ convulsions, diarrhea, headache, seizures, rapid pulse, difficulty breathing, stomach pains, vomiting, weakness
  10. 10. Poisonous Gymnosperms • All cycads and zamias have poisonous fleshy seeds ▫ BUT… if the azoxy alkaloids are washed out, they can be eaten (or flour made from them), as was common practice among the Seminole tribe of Florida Fern palm Cycas circinalis L., Cycadaceae False sago palm Dioon edule Lindl.Zamiaceae Coontie Zamia integrifolia L. f., Zamiaceae
  11. 11. Poisons and the Criminal Arts • Agrippina (19-59 AD) ▫ Empress and wife of Emperor Claudius and mother of Nero ▫ Used poisonous mushrooms to kill Lollia Paulina, Marcus Sianus, and her husband Claudius, among others
  12. 12. The execution of Socrates – Plato’s account Socrates walked about, and presently, saying that his legs were heavy, lay down on his back--that was what the man recommended. The man--he was the same one who had administered the poison--kept his hand upon Socrates, and after a little while examined his feet and legs, then pinched his foot hard and asked if he felt it. Socrates said no. Then he did the same to his legs, and moving gradually upward in this way let us see that he was getting cold and numb. Presently he felt him again and said that when it reached the heart, Socrates would be gone. The coldness was spreading about as far as his waist when Socrates uncovered his face, for he had covered it up, and said--they were his last words--Crito, we ought to offer a cock to Asclepius. See to it, and don't forget.
  13. 13. Poison Hemlock Conium maculatum L., Apiaceae • European poison hemlock made famous by Socrates’ execution (contains toxic pyridine alkaloids) • Active Compound: ▫ Cicutoxin, in root and above- ground parts: is a violent convulsant that acts directly on the central nervous system • Symptoms: ▫ 2-3 cm section of root can kill an adult
  14. 14. Medicine or Poison? The distinction between poison and medicine often comes down to two simple points: dose and intent. “Natural” does not always = safe!!
  15. 15. Poisons and the criminal arts • Cleopatra (51-30 BC) • Tested poisons on her slaves ▫ Henbane  Hyoscyamus niger L., Solanaceae ▫ Belladonna; Deadly nightshade  Atropa belladonna L., Solanaceae ▫ Poison nut  Strychnos nux-vomica L., Loganiaceae
  16. 16. Deadly Nightshade Atropa belladonna L., Solanaceae • It was used in traditional treatments for centuries for an assortment of conditions including ▫ Headache ▫ Menstrual symptoms ▫ Peptic ulcer disease ▫ Inflammation ▫ Motion sickness ▫ Mydriatic (pupil dilator) • Plant occasionally used as a recreational drug because of the vivid hallucinations and delirium that it produces. ▫ Unpleasant hallucinations. Recreational use is considered extremely dangerous because of the high risk of unintentional fatal overdose. ▫ The CNS effects of atropine include memory disruption, which may lead to severe confusion
  17. 17. Deadly Nightshade Atropa belladonna L., Solanaceae • Toxicity ▫ Berries are attractive & taste sweet, but consumption can be fatal, esp. in children ▫ Anti-cholinergic ▫ Symptoms include: dilated pupils, sensitivity to light, blurred vision, tachycardia, loss of balance, staggering, headache, rash, flushing, severely dry mouth and throat, slurred speech, urinary retention, constipation, confusion, hallucinations, delirium, and convulsions
  18. 18. Deadly Nightshade Atropa belladonna L., Solanaceae • Source of atropine ▫ Useful in management of bradycardia following a myocardial infarction ▫ Used in management of hypotension that is associated with slow heart rate ▫ Eyedrops or ointment to open iris for eye exams, surgical procedures, and to treat anterior uveitis ▫ Antidote for cholinergic crisis (such as induced by physostigmine or nerve gas) • Source of hyoscamine and scopolamine – used in functional gastric disorders
  19. 19. Poison nut Strychnos nux-vomica L., Loganiaceae • Active Compound: ▫ Indole alkaloids (strychnine and brucine) from dried ripe seeds; all parts contain strychnine • Symptoms: ▫ Agitation, muscle spasms, convulsions ▫ Extremely toxic, strychnine is fatal to humans at doses of 60- 90 mg
  20. 20. Henbane Hyoscyamus niger L., Solanaceae • Traditionally used in combination with Atropa belladonna and Datura spp. for pyschoactive effects (hallucinogen) in witches’ brew • Source of hyoscamine and scopolamine • Toxicity: ▫ Symptoms include hallucinations, dilated pupils, restlessness and flushed skin Scopolamine/Hyoscine Hyoscamine
  21. 21. Jimsonweed Datura stramonium L., Solanaceae • Used as recreational psychoactive drug – users often unaware of toxicity/poisonous nature of plant • Active Compound: ▫ Scopalamine: most found in leaves, unripe capsules, especially seeds • Symptoms: ▫ Even small amounts fatal; symptoms similar to Atropa belladonna (anti-cholinergic; flushed skin, dilated pupils, dry mouth, delirium, death from respiratory failure)
  22. 22. Scopolamine (aka Hyoscine) • Medicinal applications: ▫ Remedy for motion sickness  Oral dose or by patch ▫ Postoperative nausea/vomiting ▫ Gastrointestinal spasms • Toxicity: ▫ Symptoms include: tachycardia, arrhythmia, blurred vision, photophobia, urinary retention, dry mouth, skin reddening • Overdose/poisoning can be treated with physostigmine, a plant compound from the Calabar bean (Physostigma venenosum)
  23. 23. Hyoscyamine • Medicinal uses: ▫ Treatment of certain GI disorders (peptic ulcers, irritable bowel syndrome, colic) and control some of the symptoms of Parkinson’s disease • Toxicity ▫ Symptoms include headache, nausea, vomiting, disorientation, hallucinations, euphoria, sexual arousal and short-term memory loss
  24. 24. Calabar bean Physostigma venenosum Balf. f., Fabaceae • Calabar bean ▫ Historical ‘ordeal’ bean in the Calabar area of Nigeria ▫ Given to people on trial – if died, were guilty, if vomit & live, not guilty • Physostigmine ▫ Medicinal uses: myasthenia gravis, glaucoma, Alzheimer's disease and delayed gastric emptying ▫ Antidote of choice for Datura stramonium & Atropa belladonna poisoning ▫ Toxicity: cholinergic syndrome (SLUDGE: salivation, lacrimation, urination, defecation, gastrointestinal upset, vomiting)
  25. 25. Poisons in Mythology • Plant teratogen causes Cyclopia! • Veratrum album L., V. californicum Durand and V. viride Aiton, Melanthiaceae [false hellebore] – case of mistaken identity with other hellebore (Helleborus spp., Ranunculaceae) used in ancient Greek medicine as purgative • Consumption during early pregnancy (in humans and other animals – esp. common in sheep) results in cyclopia ▫ Single eye, often missing nose ▫ Usually stillborn • Responsible compound: cyclopamine
  26. 26. False Hellebore/ White Hellebore Veratrum album L., Melanthiaceae Hellebore/ Black Hellebore Helleborus niger L. Ranunculaceae
  27. 27. Groundsels; Ragworts Senecio spp., Asteraceae • Mistaken identity – confused with a Gnaphalium spp.& included in herbal remedy for colds • Active Compound: ▫ Hepatotoxic pyrrolizidine alkaloids • Symptoms: ▫ Ingestion results in acute illness and death in livestock and humans Senecio flaccidus L. (Hook)
  28. 28. Oleander Nerium oleander L., Apocynaceae • Examples of poisoning events: ▫ Ingestion after confusion with eucalyptus ▫ Ingestion by children ▫ Suicide attempts • Active Compound: ▫ Cardioactive glycosides; oleandrin is the main glycoside from leaves • Symptoms: ▫ Ingestion results severe vomiting, bloody diarrhea, irregular heartbeat, drowsiness, unconciousness, respiratory paraylysis, fatal Advisory Council, Zayed Complex for Herbal Research and Traditional Medicine, Abu Dhabi, UAE
  29. 29. Ginkgo: Poison or Medicine? Both? • Ginkgo biloba L., Ginkgoaceae • Leaves used in herbal supplements for improved cognitive function • Seeds contain a neurotoxin: ▫ 4-O-methyl pyridoxine (ginkgotoxin)  Interferes with amino acid metabolism  Results in convulsions and death (27% lethality) ▫ Fruit pulp causes allergic contact dermatitis Hortus Botanicus in Leiden, The Netherlands. Oldest Ginkgo in Europe. Ginkgo fruits
  30. 30. Autumn crocus; Meadow saffron Colchicum autumnale L., Colchicaceae • Colchicine derived from this plant used medicinally to treat gouty arthritis • Active Compound: ▫ Colchicine & other alkaloids ▫ Highest concentration is in seeds and corm  Amount of colchicine in 2-3 seeds can kill • Poisoning Symptoms: ▫ Burning of throat & stomach, vomiting, purging, weak-quick pulse, kidney failure, respiratory failure, often fatal, flowers have been fatal to children
  31. 31. Colchicine • 1st isolated in 1820 • Used as alternative gout treatment for those unable to tolerate NSAIDs • How it works: it inhibits deposition of uric acid (urate crystals), raises tissue pH by inhibiting glucose oxidation, reducing production of lactic acid in leukocytes • Plant extract not used because colchicine is highly toxic, and dose must be controlled • History ▫ 1st described by Dioscorides as a gout treatment in De Materia Medica ▫ Used in ancient Islamic medicine & in Europe; Benjamin Franklin in USA used it to treat his gout ▫ 2009 – FDA approved for gout treatment Colchicum autumnale (Colchicaceae) Pain of gout
  32. 32. Draining of dropsical fluid, 1741 Digitalis purpurea L. Common Foxglove
  33. 33. Foxglove Digitalis purpurea L., Plantaginaceae • 1700’s British folk medicine • William Withering published book in 1785 based on the accounts of an “old woman in Shropshire” • Used in treatment of dropsy • Still used for congestive heart failure • Led to discovery of digitoxin and digoxin, found in leaves, seeds and flowers • Toxicity: therapeutic dose is close to the toxic dose ▫ Poisoning can occur from the plant or overdose of medication ▫ Death from Digitalis poisoning from ventricular fibrillation ▫ Side effects: nausea, fatigue, salivation, severe headache, irregular heartbeat and pulse, toxicity in combo with calcium, sudden death Digitoxin Digoxin
  34. 34. Pacific Yew Taxus brevifolia Nutt., Taxaceae • History of use in Native American traditional medicine: respiratory, dermatological, gastrointestinal, and urological applications • Toxicity: • Taxines are cardiotoxic • Lethal dose: 4-20 mg/kg • Rapid absorption from GI tract to circulatory system • Affects sodium-potassium transport • Sudden death occurs with trembling, labored breathing, and collapse • Most deaths in animals that forage on leaves, human deaths rare • Taxol (Paclitaxel) ▫ Taxane diterpene discovered in 1960s NCI screen  Showed strong activity against solid tumors, melanoma, and leukemia models  Taxol concentations are low; most toxicity attributed to the taxines ▫ It took 30+ years from discovery to approval Paclitaxel
  35. 35. • One BIG problem – very low yield in plant (0.004%) ▫ Solution: semi-synthesis of taxol by conversion of metabolites available in larger quantities in needles of English Yew (Taxus baccata)  Needles were a renewable source – no need to kill the tree by removing bark • Taxol (Bristol Meyers Squibb) approved in USA in 1993 ▫ Treatment for ovarian cancer and secondary treatment for breast and non-small cell lung cancers • Docetaxel was approved in 1995 ▫ marketed as Taxotere ▫ more water soluble than taxol Breast and ovarian cancer • Abraxane – paclitaxel bound to albumin, approved in 2005 ▫ Breast cancer unresponsive to other chemotherapies Taxus baccata (Taxaceae) – English Yew Taxol
  36. 36. Docetaxel (Taxotere®) • Semi-synthetic analogue of paclitaxel • Anti-mitotic chemotherapy (interferes with cell division) • FDA approved for: ▫ locally advanced or metastatic breast cancer, head and neck cancer, gastric cancer, hormone-refractory prostate cancer and non small-cell lung cancer ▫ Maybe used alone or in drug combos • Disadvantage: prone to cellular drug resistance • Side effects: ▫ Alopecia, neutropenia, anemia
  37. 37. Mayapple; American Mandrake Podophyllum peltatum L., Berberidaceae • Long history of traditional use of rhizomes as medicine by Native Americans ▫ Dried & made into powder, then  eaten or drunk as laxative or antihelmintic  poultice applied to warts & skin growths • Currently plant extracts used as topical treatment for warts & skin growths • Toxicity: ▫ Fruits are poisonous if eaten in large amounts. Leaves and roots poisonous if consumed. Podophyllotoxin (medicinal compound) is poisonous if taken internally.
  38. 38. Etoposide • Marketed as VePesid® ▫ Small cell lung cancer, testicular cancer & lymphomas • antineoplastic or cytotoxic chemotherapy drug • It is a semisynthetic derivative of podophyllotoxin used in the treatment of certain cancers: ▫ Testicular, bladder, prostate, lung, stomach, and uterine, cancers. Hodgkin's and non-Hodgkin's lymphoma, mycosis fungoides, Kaposi's sarcoma, Wilm's tumor, rhabdomyosarcoma, Ewing's sarcoma, neuroblastoma, brain tumors • Administered orally • Side Effects: ▫ Low white blood cell count, Low platelet count, Hair loss , Menopause, Loss of fertility, Nausea and vomiting, Low blood pressure
  39. 39. Teniposide • Teniposide marketed as Vumon®  brain tumors, childhood acute leukemia • Administered by injection • Semisynthetic derivative of podophyllotoxin ▫ Used in combination with other approved anticancer agents for induction therapy in patients with refractory childhood acute lymphoblastic leukemia. • Side-Effects ▫ Severe myelosuppression with resulting infection or bleeding may occur; hypersensitivity reactions
  40. 40. (+)-Tubocurarine Dart Poisons
  41. 41. The varzea
  42. 42. Dart Poisons • Neuromuscular blocking agents ▫ Isoquinoline & indole alkaloids ▫ (+)-tubocurarine leading agent ▫ Competes with acetylcholine for cholinergic receptors at the motor endplate, preventing formation of action potential ▫ Causes death by paralyzing the respiratory system, causing asphyxiation • Loganiaceae & Menispermiaceae families are primary plant sources ▫ Strychnos spp. (Loganiaceae) ▫ Chondrodendron tomentosum Ruiz & Pav., Menispermiaceae (curare vine) Chondrodendron tomentosum
  43. 43. Curare vine Chondrodendron tomentosum Ruiz & Pav., Menispermiaceae • (+)-Tubocurarine ▫ Skeletal muscle relaxant ▫ Helped to revolutionize surgery – less anesthesia was necessary to perform operations ▫ Acts as a long-duration, non-depolarizing neuromuscular blocking agent that is a competitive antagonist of nicotinic neuromuscular acetylcholine receptors ▫ Rarely used today as an adjunct for clinical anesthesia because safer alternatives such as cisatracurium and rocuronium are available.
  44. 44. Useful poisonous plants in the Mediterranean Pantelleria
  45. 45. Basket weaving for Agricultural & Fishing Tools Euphorbiaceae
  46. 46. Daphne gnidium L., Thymelaeaceae Ethnobotanicals uses: • Insect repellent (ticks and fleas) • Hemostatic
  47. 47. Daphne gnidium poisoning • Leaves are the most toxic • Symptoms include: ▫ Headache ▫ Shivering ▫ Paleness ▫ Pupil dilatation ▫ Mouth and lips swelling ▫ Diarrhea and digestive spasms ▫ Convulsion ▫ Pulmonary disorders ▫ Death
  48. 48. Castor bean Ricinus communis L., Euphorbiaceae • Castor oil extracted from seeds is used medicinally as laxative – but eating the seeds can kill • Active Compound: ▫ Ricin: a highly poisonous phytotoxin (plant protein) ▫ FBI lists ricin as the 3rd most poisonous substance known  3,000 x more toxic than cyanide  12,000 x more toxic than rattlesnake venom • Toxicity: ▫ Symptoms include nausea, muscle spasms, purgation, convulsions, and death (accompanied by hemorrhage, GI edema and degeneration of kidneys)
  49. 49. Poisonous plants in the home and yard
  50. 50. Calcium oxalate is found in many house plants • Symptoms of poisoning: ▫ Dermatitis ▫ Swelling of the tongue, can lead to asphyxiation ▫ Irritation/burning in the mouth ▫ Development of kidney stones (edible plants i.e. Rumex spp., dock) ▫ Toxic to humans and pets
  51. 51. Poisonous house plants from the Araceae family contain calcium oxalate Philodendron Philodendron spp. Dumbcane Dieffenbachia maculata Caladium; Elephant Ear Caladium spp.
  52. 52. Abrus precatorius L., Fabaceae (rosary pea; jequirity bean) • Toxic effect from chewing the seeds • Active Compound: ▫ Abrin (phytotoxin similar to ricin) & abric acid from thoroughly chewed seeds • Symptoms: ▫ Gastrointestinal distress ▫ Fatal to humans and animals
  53. 53. Rhus Dermatitis • Rhus = group of plants responsible for more cases of Allergic Contact Dermatitis (ACD) than any other allergen • Rhus is the botanical synonym for Toxicodendron in the Anacardiaceae family • Pentadecylcatechol is an allergin found in the plant sap (oleoresin)  Poison ivy  Poison oak  Poison sumac  Mango (rind)  Lacquer tree  Cashew nut  Indian marking nut
  54. 54. Rhus Dermatitis Plants • Anacardiaceae ▫ Toxicodendron radicans (L.) Kuntze [Poison Ivy] ▫ Toxicodendron diversilobum (Torr. & A. Gray) Greene [Poison Oak] ▫ Toxicodendron vernix (L.) Kuntze [Poison Sumac] ▫ Mangifera spp. [Mango]
  55. 55. Rhus Dermatitis Plants • Anacardiaceae ▫ Toxicodendron vernicifluum (Stokes) F.A. Barkley [Lacquer Tree] ▫ Anacardium occidentale L. [Cashew Nut] ▫ Semecarpus anacardium L. f. [Indian marking nut]
  56. 56. Conclusions • There are many poisonous plants that actually serve an important role to many in terms of: ▫ Food security ▫ Medicine ▫ Fishing tools ▫ Hunting tools • Poisonous chemicals can be concentrated in specific plant tissues • In most cases, there is a thin line between poison and medicine and it all comes down to 2 key factors: dose and intent.
  57. 57. Acknowledgements • Emory University Herbarium Staff and Volunteers • Philanthropic donation • How to help the Emory Herbarium: ▫ Support our educational outreach and research mission! We are seeking donations of funds, books, ethnobotanical objects, and historic herbaria collections. Visit our website for more info: https://scholarblogs.emor y.edu/emoryherbarium/

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