POISONOUS PLANTS

2. POISONOUS PLANTS Treat unknown plants with respect, and teach your children to do the same. Many plants are poisonous to varyingdegrees. Many plant poisons areeitheralkaloidsor steroids, a potentialsource of drugs orcommercialpoisonsfor use as insecticides,herbicides and fungicides. Use of plant poisonsin the capital punishment– well known from thestory: death of Greek Philosopher Socrates- sentenced todrink thejuice of poisonhemlock Conium maculatum.

3. Plants cannot escape their predators-need protection from herbivores. Some have physical defenses:- thorns, prickles, hairs, bristles. BUT most common protection is chemicals. Natural selection has produced many chemical compounds to keep away herbivores-during thousands of years.

4. Tannins- emerged relatively early in the evolutionary history of plants. More complex molecules-Polyacetylenesare foundin younger groups of plants likeAsterales. Consumption of such plants may produce negative effects-mild discomfort to death.

5. Same poisonous compounds may be ofmedicinalvalue. Many unanswered questions about this chemical defence system..

6. Questions include: Which plants have which type of defenses? (2)Which herbivores are the plants defended against? (3)What are the chemical structures of the compounds that provide defense? (4)What are the potential medical uses of these compounds?

7. An active area of research with important implications in the field of medicinal chemistry. Human fatalities caused by poisonous plants-especially from accidental ingestion.

8. Poisonous Food Plants Many food plantstoxic unless processed, or are toxic at certain stages of their life. Apple (Malusdomestica)-Seeds mildly poisonous, contain small amount of amygdalin, a cyanogenic glycoside. Quantity contained usually not enough to be dangerous to humans, but if enough seeds ingestedcan provefatal.

9. Cassava (Manihotesculenta) Roots +Leaves contain 2cyanogenicglucosides; linamarin&lotaustralin- decomposed by linamarase-a naturally occurring enzyme in cassava, liberatingHCN. Sweet or Bitter Varietiessignify absence or presence of toxic levels of cyanogenicglucosides. ‘Sweet' cvcan produce 20 mg of CN/kgof fresh roots-bitter ones produce more 1 g/kg.

10. Toxinvery high indrought conditions. 40 mg of pure cassava cyanogenicglucosidesufficient to kill a cow. Causessevere calcific“Pancreatitis”in humans-chronic (inflammation of pancreas). Processing (soaking, cooking, fermentation) of roots necessary to remove the toxins &avoid getting sick.

11. "Low-level CNexposure associated with the development of goiter&tropical ataxic neuropathy-a nerve damaging disorder; renders a person unsteady & uncoordinated. Severe CNpoisoning-associated with outbreaks of a debilitating, irreversible paralytic disorder called KONZO-in some casesdeath.

12. Incidence of KONZO&TropicalAtaxicNeuropathycan be as high as 3 %in some areas. For smaller-rooted sweet varieties-cooking sufficient to eliminate all toxicity. CN is carried away in the processing water. Larger-rooted, bitter var. used for production of flour or starch must be processed to remove cyanogenicglucosides.

13. Industrial production of cassava flour, even at the cottage level, may generate enough CN&cyanogenic glycosides in the effluents to have a severe environmental impact. • Cherry (Prunuscerasus), + other Prunus species -peach (P. persica), plum (P. domestica), almond(P. dulcis), & apricot (P. armeniaca)-Leaves + seeds contain CyanogenicGlycosides.

14. Indian pea (Lathyrussativus) • LegumefromAsia & East Africa – • insurance crop for use duringfamines. • Produces a high-protein seed. • Seeds contain variable amounts of  ODAP • (β-N-Oxalyl-L-α,β- diaminopropionic acid) • a neurotoxic amino acid.

15.  ODAP causes  paralysis if eaten over a • long period. • Considered as the cause of disease • Neurolathyrism, • a  neurodegenerative disease –causes • paralysis of the lowerbody & • emaciation(weight loss) of • glutealmuscle.

16. Disease seen to occur • after famines in Europe (France, Spain, • Germany), North Africa &  South Asia. • Still prevalent in Eritrea,Ethiopia • & parts of Afghanistan • ifLathyrus seed exclusive or main • source of nutrients for long.

17. Nutmeg (Myristicafragrans) • -Contains Myristicin- a naturally • occurring insecticide &acaricide with possible • neurotoxiceffects on neuroblastoma cells. • Psychoactive properties at doses much higher • than used in cooking. • Raw produces anticholinergic-like symptoms, attributed to myristicin&elemicin(a phenylpropene).

18. Myristicin intoxicationcauses • conditionbetween • waking - dreaming; • euphoria is reported, • nauseaoften experienced. • Users report bloodshot eyes – • memory disturbances.

19. Induces hallucinogenic effectslike • visual distortions. • Intoxication peak reaching- • may take 7hours, • effects can be felt for 24 hours, • with lingering • effects lasting up to 72 hours.

20. Kidney bean or common bean  • (Phaseolusvulgaris) • Toxic compoundphytohaemagglutinin • (a lectin) -in many varieties of commonbean • especiallyred kidney beans. • Lectin- number of effects on cell metabolism. • Induces mitosis, affects cell membrane • transport & permeability to proteins. • Primary symptoms of poisoning-nausea, • vomiting, diarrhea

21. Onset from 1 - 3 hours after • consumption of improperly • prepared beans, symptoms typically • resolve within a few hours. • ]Consumption of as few as 4 or 5 • raw kidney beans sufficient • to trigger symptoms.

22. Phytohaemagglutinin can be • deactivated by cooking beans at • 100 °C for 10 minutes- (degrades toxin). • For dry beans initial soak of at least • 5 hours in waterrequired; • the soaking water is discarded.

23. Lower cooking temperatures may • have the paradoxical effect of • potentiating the toxic effect of • haemagglutinin. • Beans cooked at 80 °C are • reported to be up 5 times as toxic • as raw beans.

24. Outbreaks of poisoning associated with • the use of slow cookers, the low cooking • temperatures-unable to degrade • the toxin. • Lima bean or butter bean  • (Phaseoluslunatus) • Raw beans contain dangerous amounts • of linamarin, a cyanogenicglucoside.

25. Lupin -Some varieties have edible seeds • Sweet Lupins– lesstoxicalkaloids • lupinine & sparteine; Bitter have more. • Onions and Garlic. • Alliums- contain thiosulphate, • in high doses • toxic to dogs, cats + otherlivestock.

26. Potato (Solanumtuberosum) • Contain toxic compounds called • Glyco-alkaloids- • most prevalent solanine&chaconine. • Solanine found also in Atropabelladonna • ("deadly nightshade") & • Hyoscyamusniger ("henbane").

27. Concentration of glycoalkaloid in wild potatoes suffices to produce toxic effects in humans. • Toxin affects - nervous system, causing headaches, diarrhea, intense digestive disturbances, cramps, weakness & confusion, in severe cases coma/ death.

28. Poisoning from cultivated potatoes very rare -toxic compounds in general concentrated in the green portions & fruits, cultivated potato varieties contain lower toxin levels. • Cooking at high temperatures (over 170 °C) partly destroys the toxin. • Exposure to light, physical damage & age increase glycoalkaloid content within the tuber,  highest concentrations occurring just underneath the skin.

29. Tubers exposed to light turn green from • chlorophyll synthesis-a visual clue to areas of the • tuber that may have become more toxic. • Nota definite guide, as greening &glycoalkaloid • accumulation can occur independently of each other. • Some potatocv contain greater glycoalkaloid concentrations than others; breeders developing new varieties test for this, and sometimes have to discard an otherwise promising cv. • Breeders keep solaninelevels below 200 mg/kg.

30. Ifcommercial varieties turn green-they can approach concentrations of solanine of 1000 mg/kg. • Americans consume 12.5 mg/day of solanine from potatoes (toxic dose actually several times this, depending on body weight). • No reported cases of potato-source solanine poisoning, and most cases involved eating green potatoes or drinking potato-leaf tea.

31. Rhubarb (Rheum rhaponticum) • Petiolesedible-leaves contain notable quantities • ofoxalic acid- aNephrotoxic&corrosiveacid- • present in many plants. • Symptoms of poisoning-kidney disorders, • convulsions & coma, Rarely fatal. • LD50 (median lethal dose) for pure oxalic acid is • about 25 grams for a 65kghuman.

32. Oxalicacid content in leaves varies. • Typicalvalue ± 0.5%- if 5 kg of extremely sour leaves consumed -reach an LD50 of oxalic acid. • Cooking leaves with soda can make them more poisonous by producing soluble oxalates. • Leaves are believed to alsocontain an • unidentified toxin- might beananthraquinone • glycoside (also calledsennaglycosides).

33. Inpetioles-amount of oxalic acid much lower;about 2-2.5% of the total acidity which is dominated by malicacid. • Even raw stalks may not be hazardous. • Tart taste of raw stalks is so strong as to be unpalatable to many.

34. Tomato (Solanumlycopersicum). Leaves +stems contain solanine-toxic if ingested, causing digestive upset &nervous excitement. Use of tomato leaves as a tea (tisane) has been responsible for at least 1death.

35. Greenunripe fruits also contain small amounts of the poisonous alkaloidtomatine-levels generally too small to be dangerous. Ripe tomatoes do not contain any detectable tomatine. Plantscan be toxic to dogs if they eat large amounts or chew plant material.

36. OTHER POISONOUS PLANTS Abrusprecatorius(known commonly as jequirity, crab's eye, rosary pea, 'John Crow' bead, precatory bean, Indian licorice, akar saga, giddeegiddee, jumbie bead, ruti, and weather plant). Attractiveseeds (usually about the size of a ladybug, glossy red with one black dot) contain abrin-related to ricin, &very potent.

37. PoisoningSymptoms: nausea, vomiting, convulsions, liver failure, &death, usually after several days. Seeds used as beads in jewelry-dangerous; inhaled dust is toxic and pinpricks can be fatal. Seeds attractive to children BUT ingestinga single seed can kill an adult human.

38. Aconitum (Several species, commonly calledaconite,wolfsbane  and monkshood) All parts poisonous-an alkaloid called aconitine, which disables nerves, lowers blood pressure, and can stop the heart. Even casual skin contact should be avoided; symptoms include numbness, tingling, &cardiac irregularity.

39. Usedas poison for bullets (by Germany in WWII), as bait +arrow poison (ancient Greece), to poison water supplies. If ingested-usually causes burning, tingling, numbness in the mouth, followed by vomiting and nervous excitement. A quick-acting poison-usedin the past for killing wolves.

40. Actaeapachypoda (also known as doll's eyes or white baneberry). All parts poisonous-especially the berries, the consumption has sedative effect on cardiac muscle tissue and can cause cardiac arrest. Adeniumobesum(also known as sabi star,kudu or desert-rose) Exudes a highly toxic sap -used by the Meridian High &Hadza in Tanzania to coat arrow-tips for hunting. Aesculushippocastanum(commonly known as horse-chestnut) All plant parts poisonous-causing nausea, muscle twitches, and sometimes paralysis. African sumac – see Rhuslancia.

41. Agave. Juiceof a number of species causes acute contact dermatitis, with blistering lasting several weeks &recurring itching for several years thereafter. Ageratinaaltissima(commonly known as white snakeroot). All parts poisonous, causing nausea -vomiting. Often fatal. Milk from cattle that have eaten white snakeroot can sicken, or kill, humans (milk sickness).

42. Agrostemmagithago(common name corn cockle) Contains saponinsgithagin&agrostemmicacid. All plant partspoisonous -may produce chronic or acute, potentially fatal poisoning. Usedin folk medicine to treat a range of ills, from parasites to cancer . No known recent clinical studies of corn cockle which provide a basis for dosage recommendations, however doses higher than 3 g [of seeds] are considered toxic.

43. Aquilegia (also known as columbine). Several species. Seeds &roots contain cardiogenic toxins -cause both severegastroenteritis& heart palpitations if consumed. Flowers of various species consumed in moderation by Native Americans as a condiment with other fresh greens-very sweet, and safe if consumed in small quantities.

44. Native Americans also used very small amounts of the root as an effective treatment for ulcers. Medicaluse of this plant difficult due to its high toxicity; columbine poisonings are easily fatal.

45. Arecacatechu(commonly known as betel nut palm and pinyang). Containsan alkaloid related to nicotine -addictive. Producesa mild high, some stimulation, and lots of red saliva, which cannot be swallowed as it causes nausea. Withdrawal causes headache &sweats. Use correlated with mouth cancer, to a lesser extent asthma and heart disease.

46. Arum maculatum(commonly known as cuckoo-pint, lords and ladies, jack in the pulpit, wake robin, wild arum, devils and angels, cows and bulls, Adam and Eve, bobbins and starch-root). All parts of the plant can produce allergic reactions. Bright red berries contain oxalates -can cause skin, mouth +throat irritation, resulting in swelling, burning pain, breathing difficulties & stomach upset. Mostcommon causes of plant poisoning.

47. AsparagusThe berries arepoisonous. Atropa belladonna (commonly known as deadly nightshade, belladonna, devil's cherry and dwale, an Anglo-Saxon term meaning stupifying drink). One of the mosttoxicplant - in the Western hemisphere. All parts containtropanealkaloids. Active agents - atropine,hyoscine(scopolamine), &hyoscyamine,withanticholinergicproperties.

48. Symptomsof poisoning :- dilated pupils, sensitivity to light, blurred vision,  tachycardia, loss of balance, staggering, headache,  rash, flushing, dry mouth and throat, slurred speech,  urinaryretention,  constipation, confusion,hallucinations, delirium, and convulsions.

49. Root generally most toxic part, but can vary from one specimen to another. Ingestion of a single leaf of the plant can be fatal to an adult. Casual contact with the leaves can cause skin pustules. Berriespose greatest danger to children-look attractive and have a somewhat sweet taste.

50. Consumptionof 2-5berries by children and 10-20 by adults can be lethal. 2009-case of A. belladonnamistaken for blueberries, with 6berries ingested by an adult woman, was documented to result in severe anticholinergicsyndrome.