poisonous plants and fungi

Question 1

what are poisonous plants and fungi?

Answer 1

One which causes a serious departure from normal health when a small quantity of the plant/fungus or certain part of the plant/fungus is eaten by an animal susceptible to its effects.’

Question 2

How to assess poisonous plant

Answer 2

Accessibility to poisonous plants/fungi is relatively easy. These may be found in the countryside (e.g. fields, woods, and hedges), but many are kept in houses and greenhouses as ornamental plants

Question 3

Explain why the number of cases of plant poisoning increases during Autumn and summer?

Answer 3

The number of cases increases during late summer and autumn. This is probably because the season/time when the plants produce berries coincides with vacation time.

Question 4

children require a smaller dose to have a similar toxic effect; greater chance of displaying toxic symptoms. true/false

Answer 4

true

Question 5

State the 3 groups plants and fungi are classed as poisonous

There are plants, which are undoubtedly toxic, such as ___________, but they have medical application in defined doses.

There are plants that are toxic and have no medicinal potential or this has not been realized yet
e.g. _____________ that contains ___________(a polyyne compound) and _____________ (a peptide) in _________ (death cap). (Yew and taxol!)

There are plants and fungi that are toxic and are abused for their hallucinogenic properties such as _____________ and ____________ species (liberty cap).

Answer 5

There are plants, which are undoubtedly toxic, such as Atropa belladonna, but they have medical application in defined doses.

There are plants that are toxic and have no medicinal potential or this has not been realized yet
e.g. Oenanthe crocata that contains oenanthotoxin (a polyyne compound) and amatoxins (a peptide) in Amanita phalloides (death cap). (Yew and taxol!)

There are plants and fungi that are toxic and are abused for their hallucinogenic properties such as nutmeg and Psilocybe species (liberty cap).

Question 6

Symptoms of plant ingestion

Answer 6

: nausea, vomiting, diarrhoea and stomach cramps. Blistering of the mouth and other lining may be present. This is dependent on the plant involved (presence of irritants). The above symptoms are non-specific and occur with most cases of poisoning. These are called cases of ingestion.

Question 7

list the symptoms of plant poisoning

Answer 7

In some cases systemic effects will be forth coming i.e. effects on CNS, muscle, respiration and heart. These are called cases of poisoning.
The symptoms displayed are dependent on what and how much has been consumed.

Question 8

• was set up in 1963 for advice on all types of poison

Answer 8

National Poisons Information Service (NPIS)

Question 9

List examples of plant that causes constipation

Answer 9

ragwort and acorns

Question 10

List some some poisonous plants that causes blood disorders

Answer 10

Mercury and bracken

Question 11

State the problems of diagnosis with plants/fungi poisoning

It is usually difficult to identify a plant poison from the symptoms displayed. Hence, diagnosis, in order to start treatment on the patient is not possible from this approach.

Furthermore, information is required about the locality of where the person or animal was, and amount and what was consumed.

The problem could stem from something unrelated to plants e.g. _____________
Not all plant poisons cause diarrhoea. A few plants cause constipation e.g. ragwort and acorns. Some cause blood disorders e.g. dog’s mercury and bracken.

Toxic symptoms are not always forth coming immediately e.g. _______, __________ and _________ – it takes a few hours; ______ and ___________ – about two days; bracken and ragwort – ____________

Answer 11

It is usually difficult to identify a plant poison from the symptoms displayed. Hence, diagnosis, in order to start treatment on the patient is not possible from this approach.

Furthermore, information is required about the locality of where the person or animal was, and amount and what was consumed.

The problem could stem from something unrelated to plants e.g. pesticides sprayed on plants.

Not all plant poisons cause diarrhoea. A few plants cause constipation e.g. ragwort and acorns. Some cause blood disorders e.g. dog’s mercury and bracken.

Toxic symptoms are not always forth coming immediately e.g. foxglove, hemlock and yew – it takes a few hours; nitrate and autumn crocus – about two days; bracken and ragwort – weeks to months.

Question 12

types of toxic principles in plants and fungi

Answer 12

Plant/fungi poisons may be either highly active so that a small dose gives rise to pronounced pharmacological effects, or may be relatively less active but when consumed in large quantities will give rise to pronounced effects.

Toxic principles of plants/fungi may break down spontaneously, change as a result of metabolic enzymes acting on them (perhaps becoming toxic as a result), or remain intact in the body.

Usually the body attempts to make compounds more water- soluble in order to eliminate them from the body.

Question 13

What are the effects of toxic compounds?

Local effects such as ____________

Systemic effects and these may be _________________

Others effects such as _______and ____________.
The nature of the toxic principles is not known for all the plants/fungi classed as ‘poisonous’.

Most of the toxic principles can be divided into similar classes as for the ____________

Answer 13

Local effects such as blistering especially the lining of the mouth and intestine.

Systemic effects and these may be direct on one or more organs e.g. heart, CNS and lungs.

Others effects such as liver damage or oxalates coupling with calcium and causing hypocalaemia and kidney damage.

The nature of the toxic principles is not known for all the plants/fungi classed as ‘poisonous’.

Most of the toxic principles can be divided into similar classes as for the beneficial natural products

Question 14

Some fungi accumulate certain types of heavy metals and produce compounds that are not directly toxic .true/false?

Some types of fungi are able to accumulate certain types of heavy metals e.g. _________, ___________, ________, __________. Some fungi produce compounds that are not directly toxic, but only in the presence of ethanol by interfering with the alcohol metabolism (e.g. ___________ (ink caps) of fungi contains a compound _____________).

Answer 14

Some types of fungi are able to accumulate certain types of heavy metals e.g. cadmium, caesium, iron, mercury. Some fungi produce compounds that are not directly toxic, but only in the presence of ethanol by interfering with the alcohol metabolism (e.g. Coprinus spp (ink caps) of fungi contains a compound coprine).

Question 15

Name the Britain’s most toxic plant used as one time to treat trigeminal neuralgia

_______, a diterpene alkaloid obtained from Aconitum species

common names are ________ and __________

Answer 15

Aconitine, a diterpene alkaloid obtained from Aconitum species

common names are monkshood and wolfbane

Question 16

Facts about Aconitine

____________- varies with stage of growth. Roots of the plant were previously used to provide _______for various conditions. The roots have been mistaken for ____________ leading to fatalities. As much as ________ is considered to be enough to kill

Answer 16

Alkaloid content varies with stage of growth. Roots of the plant were previously used to provide pain relief for various conditions. The roots have been mistaken for horse radish leading to fatalities. As much as 5 mg is considered to be enough to kill

Question 17

Mode of action of Aconitine

Answer 17

Aconitine and related structures are complex terpene esters and they are neurotoxins acting on the sodium channels. No antidote available

Question 18

Symptoms of poisoning with Aconitine

9

Answer 18

! Symptoms of poisoning include burning of the mouth and throat, abdominal pain, intense thirst, headache, slow pulse, paralysis, convulsions, delirium and coma. Treatment would be symptomatic.

Question 19

Chronic intake of certain amino acid leads to great toxicity. True/false?

Answer 19

True

Question 20

Where toxic amino acids commonly occur

These types of substances are commonly occurring in the seeds of the ___________________ e.g. consuming large quantities of chick peas during drought season.

Answer 20

These types of substances are commonly occurring in the seeds of the bean family (Fabaceae) e.g. consuming large quantities of chick peas during drought season.

Question 21

Chick peas contain —-

Answer 21

α-amino-β-oxalylamino propionic acid

Question 22

Toxic amino acid can cause what type of condition?

It can cause _____________. Condition that develops is called ‘___________’- toxicity of the nerves.

Answer 22

It can cause paralysis of the lower limbs. Condition that develops is called ‘neurolathyrism’- toxicity of the nerves.

Question 23

Large amount of sweet peas cause

Answer 23

‘osteolathyrism’.

Question 24

Some species of the genera inocybe and clitocybe produce ——-

Answer 24

Muscarine

Question 25

Facts about L(+) Muscarine

Answer 25

L (+) Muscarine has structural similarities to the transmitter acetylcholine and thus activates acetylcholine receptors. Unlike acetylcholine, muscarine does not have an ester bond and cannot be hydrolysed by acetylcholinesterase and results in prolonged stimulation.

Question 26

State the symptoms experienced 15-30mins after consuming fungus that produces muscarine

10

Answer 26

After 15-30 minutes of having consumed the fungus, typical symptoms are heavy breathing, salivation, lachrymation, vomiting, diarrhoea, colic, constriction of the pupils, decreased blood pressure, slow pulse and bronchial asthma; all relating to over stimulation of the acetylcholine receptors.

Question 27

What can be used to counteract the action of muscarine?

Answer 27

Atropine can be used to counteract this action. Normal dose is adult 1-2 mg IM or IV every ½ to 1 hour until toxicity subside

Question 28

Other stereoisomers of L (+) Muscarine have been isolated as well, but have reduced potency (600-12000 times less). Therefore these are not toxicologically significant. true/false

Answer 28

False

Question 29

Toxins from peptides of Amanita phalloides are———

Answer 29

Generally very toxic

Question 30

The toxins in Amanita species are subdivided into 3 namely;

Answer 30

amatoxins, phallotoxins and virotoxins.

Question 31

Amatoxins are….

Answer 31

bicyclic octa

Question 32

Phallotoxins are

Answer 32

Hepta peptides

Question 33

Virotoxins are

Answer 33

Hepta peptides with a monocyclic structure

Question 34

Toxicity symptoms caused by Amanita phalloides species

Answer 34

Initially there is the gastrointestinal phase. There is sudden onset of nausea, abdominal pain, colic, vomiting and bloody diarrhoea. Increased electrolyte loss will cause shock and cramps. This lasts for 12-24 hours, followed by a deceptive period of (12-24 hours) of recovery. The first signs of liver damage become apparent at this stage.

The liver will become enlarged and pressure sensitive. There will be jaundice, stomach and intestinal bleeding, followed by hepatic coma and death. If the liver starts to regenerate, then slow recovery is possible.

Question 35

Facts about Phallotoxins and Virotoxins

Answer 35

Phallotoxins are not easily absorbed through the gut, and have tenth of the toxicity when administered into the blood stream. Virotoxins have similar properties to phallotoxins.

Question 36

Facts about Amatoxins

The amatoxins (ring shaped made of __________) are stable to boiling and the enzymes in the ___________. They attack the nuclei of __________and stop _________. Fatal amount needed for an adult is __________. The toxic compounds are rapidly excreted in the _____, but then ____________(enterohepatic circulation). Methods are used to stop the reabsorption, but the main excretion of these compounds is through the _________. (RNA ____________ inhibited by α-amanitin leading to protein shortage in cells.)

Answer 36

The amatoxins (ring shaped made of eight amino acids) are stable to boiling and the enzymes in the GI tract. They attack the nuclei of liver cells and stop transcription of DNA. Fatal amount needed for an adult is 5-7 mg. The toxic compounds are rapidly excreted in the bile, but then reabsorbed (enterohepatic circulation). Methods are used to stop the reabsorption, but the main excretion of these compounds is through the kidneys. (RNA polymerase II inhibited by α-amanitin leading to protein shortage in cells.)