BIOTOXINS

Miscellaneous poisons

Zootoxins

A poisonous substance produced by specific types of animals that can induced harmful effects when exposed to tissues.

Poisonous animals are widely distributed throughout the animal kingdom; the only major group that seems to be exempt is the birds.

Types of Poisons

Ingested PoisonIngested Poisons are poisons that

are dangerous if consumed. The most common ingested poisons are crafted from plants or from common chemicals. Frequently, poisoning occurs accidentally when a creature unknowingly consumes a poisonous plant, or a food that has been unintentionally contaminated.

Parenteral poisons, or venoms

-Those that are produced by a specialized poison gland and administered by means of a venom apparatus.

CrinotoxinsThose that are produced by a

specialized poison gland but are merely released into the environment, usually by means of a pore.

ARACHNID POISONING

Miscellaneous poisons

Arachnids

Class: Arachnida Any arthropods comprising chiefly

terrestrial invertebrates having a segmented body divided into two regions of which the anterior bears four pairs of legs but no antennae.

E.g. Spiders, scorpions, mites and ticks

Spiders

All spiders are capable of producing venom.

Spider venoms work on one of two fundamental principles; they are either neurotoxic or necrotic.

Neurotoxic effect-Attacks the nervous system

Necrotic effect -attacking tissues surrounding the bite

and vital organs and systems.

Neutrotoxic venoms

Widow spider venom contains components known as latrotoxins, which cause the release of the neurotransmitter acetylcholine.

This can affect the body in several ways, including causing painful abdominal cramps, as well as interfering with respiration, and causing other systemic effects.

The venom of Australian funnel-web spiders and mouse spiders works by opening sodium channels, causing excessive neural activity which interferes with normal bodily function.

The venom of Brazilian wandering spiders is also a potent neurotoxin, which attacks multiple types of ion channels. In addition, the venom contains high levels of serotonin, making an envenomation by this species particularly painful.

Necrotic Venom

Spiders known to have necrotic venom are found in the family Sicariidae, a family which includes both the recluse spiders and the six-eyed sand spiders.

Spiders in this family possess a known dermonecrotic agent sphingomyelinase D.

Pathophysiology

Initial reaction: No pain from the bite Bites usually become painful and itchy within

two to eight hours. pain and other local effects worsen 12 to 36

hours after the bite, and then necrosis will develop over the next few days.

Mild symptoms include nausea, vomiting, fever, rashes, muscle and joint pain.

Severe symptoms occur including hemolysis, thrombocytopenia, and disseminated intravascular coagulation.

Venom assessment

LD-50 Give a rough approximation of the medical consequences of various spider bites to humans.

Based on experiments with laboratory mice

REPTILE POISONING

Miscellaneous poisons

Reptiles

Class: reptilia Air breathing vertebrates Characterized by completely ossified

skeleton with single occipital condyle Body is usually covered with scales or

bony plates E.g. alligators, crocodiles, lizards, snakes

and turtles.

Snake bite

The most fatal form of zoonotic poisoning

Proteins constitute 90-95% of venom's dry weight and they are responsible for almost all of its biological effects. Among hundreds, even thousands of proteins found in venom, there are toxins.

Protein and Enzymes in Snake Venoms

digestive hydrolases, L-amino acid oxidase, phospholipases, thrombin-like pro-coagulant kallikrein-like serine proteases metalloproteinases (hemorrhagins)

Damage vascular endothelium

Polypeptide toxins include cytotoxins, cardio toxins, and postsynaptic neurotoxins (such as α-bungarotoxin and α-Cobratoxin), which bind to acetylcholine receptors at neuromuscular junctions.

Inhibits angiotensin converting enzymes and potentiate bradykinin.

Phosphodiesterases 

NeurotoxinThese toxins attack cholinergic neurons by destroying acetylcholinesterase (AChE). ACh therefore cannot be broken down and stays in the receptor which causes tetany, that can lead to death.

HemotoxinsThe toxin causes hemolysis, or destruction of red blood cells (erythrocytes)

Dendrotoxins inhibit neurotransmissions by blocking the exchange of + and – ions across the neuronal membrane lead to no nerve impulse. So they paralyse the nerves

Cardiotoxins are components that are specifically toxic to the heart. They bind to particular sites on the surface of muscle cells and cause depolarisation. These toxins may cause the heart to beat irregularly or stop beating, causing death.

Venomous Snakes: Mambas Vipers Rattlesnakes King cobra Members of Naja genus

Prophylaxis

Antivenoms Usually came from animals such as sheep,

goat, horse and rabbits. The immune system of the subject animal

responds to the dose, producing antibodies to the venom's active molecules.

the antibodies can then be harvested from the animal's blood and injected into bite victims to treat envenomation.

Venomous Fish

with spines live in the Indo-Pacific seas tropical areas others live in temperate waters

VENOMOUS FISH Rajiformes (stingrays and mantas) Scorpaenidae (scorpionfish, stonefish

and lionfish) Siluroidei (catfish) Squaliformes (sharks and dogfish) Trachinidae (weevers).

They live in shallow water near the shore or near reefs and lie in sand or among rocks

MOA• inject venom through their spines • it causes intense pain near the bite and affects the muscles.

Venom from dead fish is still poisonous for up to 24 hours after the fish has died.

Poisoning from eating SEAFOOD

Ciguatoxin poisoning Poisoning from shellfish Tetrodotoxin poisoning Scombrotoxin poisoning

Ciguatoxin poisoning

• tropical reef fish barracudagrouperred snapper amber jack

Poisoning from shellfish

MusselsClamsOystersCocklesScallops

Tetrodotoxin poisoning

•porcupine fish •puffer fish• sun fish

Scombrotoxin poisoning

• fresh or canned scromboid fish:tunabonitoskipjackmackerel

-sardines-pilchards

• Cigautoxin, tetrodotoxin and poisons from shellfish affect the gut and the nervous system.

• Tetrodotoxin and the poison from the shellfish paralyse muscles, including the muscles that are used in breathing.

• Scombrotoxin causes an allergic type of reaction. • Shellfish are most poisonous at times of the year

when the dinoflagellates on which they feed multiply and form “red tides”.

 

Signs and Symptoms

• Nausea• Vomiting• Headache• Numbness• Shallow breathing• Itching• Aching muscles• FitsRare : DEATH

What to do

If the patient is stung rescue him or her immediately from the water

Soak the wounded part of the body at once in the bowl or bath of water as hot as the patient can safely bare (about 50 C ) for not more than 30 minutes.

Clean the wound and remove any broken spines

PLANT TOXINSBY Miyoba Mulambo

Bsmls 1V-C

Plants that contain atropine Cannabis Irritant plants Oleanders Ornamental beans mushrooms

Plant toxins include:

1. Atropa belladonna -a.k.a deadly night shade or enchanter’s

shade -Most common -Shrub with Bell shaped purple or red flower -Found in Europe, north africa and west AsiaUses -prevent or treat asthma in folk medicine

Plants that contain Atropine

A.k.a thorn apple, jimson weed or angel’strumpet

Funnel shaped white or mauve herb flowers

Fruits are prickly or spiny capsules and black in colour

Unpleasant smell WorldwideUses

Datura stramonium

Leaves are infused in water to make a drink Made into cigarettes and smoked Used to cause abortion.3.Hyoscyamus niger-A.k.a henbane-herb with yellow flowers and purple markings-unpleasant smell-found in north& south America, Europe,India

and western Asia

Uses

Excite brain and affect nerves that control heart, eyes, gut and bladder

Make skin and mouth dry Cause fever Wide pupils Fast breathing and heartbeat

How they cause harm

Poisonous if eaten, even when cooked or boiled because poison is not destroyed by heat

Atropa and hyoscyamus both contain sap irritant to skin and eyes

Atropa may cause poisoning to the eye Poison may be severe in old and young

children

How poisonous they are

Mistaken for spinach and the berries of Atropa for edible fruits

Are abused for their hallucinogenic effects Signs and symptoms If swallowed Red, dry skin, wide pupils, blurred vision Dry mouth and thirst Confusion and hallucination excitement

and aggression

Special danger

Fast pulse, can’t pass urine, unconsciousness

Fever and rarely fits on skin Redness and irritation Blistering In the eyes Same effects as when swallowed

Signs and symptoms continued

Give first aid If breathing stops, give mouth –mouth

respiration, heart massage It fever is present, sponge body with cool

water Give activated charcoal, make him/her

vomit Wash eye for 15-20minswith running

water Take the patient to the hospital

What to do

A.k.a marijuana, indian hemp, hashish, ganja, pot, dope and grass

Made from the indian hemp plant cannabis saliva

Uses and abuses Often abused Makes people relax Makes colours and sounds seem brighter

and louder

Cannabis

Taken as food or injected Pipe and smoked How it causes harm Affects brain How poisonous is it ? Children get signs of poisoning but

recover Less harm to adults unless when injected

Uses and abuses continued

Effects start within 10mins of smoking the drug and last for 2-3hrs

When eaten, effects start within 30-60mins and last 2-5mins

Effects are: Feeling of well-being, happiness and

sleepness but high doses may cause fear, panic and confusion

Signs and symptoms

Fast pulse, hallucinations, drowsiness, slurred speech and coughing if the drug is breathed

If injected may cause:Dizziness, fever,low blood pressureSevere headace,fever and unconsciousness What to doSame as atropines

Effects continued

Cause skin reactions Include:1. Cashew nut tree (anacardium occidentale) - tropical countries -Nut shell contains irritant brown oily juice -Roasting shell destroys chemicals2 . Dumb-cane(dieffenbachia species -lance shaped leaves with yellow or white markings -Common household plant3. spurges(Euphoria species)

Irritant plants

Large group of plants4. poison ivy-climbing plant, may be found clinging to

trees or houses5.Rhus radicans (toxicodendron

radicans)-shrub like tree with green leaves that turn

yellow, red violet in autumn6.African poison

Irritants continued

7. Mango (mangifera indica)8.Urtica dioica-common stinging nettle How they cause harm-irritates skin and brain if swallowed-dumb-cane causes sever irritations of lips,

mouth and throat and can affect heart and muscles if swallowed.

Irritants continued

Intense allergic skin reactions depends on sensitivity of the individual

Watering, blurred vision, burning pain, Swelling of face and eye lids Fever, blisters and pain that's worse in bright

light

What to do:-wash skin with soapy water-Apply hydrocortisone cream

How they cause harm

Nerium oleander- Evergren shrub. White pink flowers with

a sweet smell- China,india, mediterranean- Garden plant- All parts poisonous, crushed leaves and

stems are irritants to skin

oleanders

Thevetia peruviana-Small ornamental tree, bright yellow

flowers-Round fruits, green when unripe and

black when ripe-Milky sap.-Central and south America, gardens in

tropics and subtropical regions

Poison affect heart in similar way to digitalis

Serious poisoning has been reported in children and adults from eating fruit..very poisonous

Special danger:-bright flowers are attractive to children-Eaten by people who want to kill

themselves

How it causes harm

Numbness or burning pain in mouth, Nausea and vomiting which maybe

severe Diarrhea, belly pain, drowsiness,possible

fits Unconsciousness, pulse maybe slow or

fast Effect of heart may result to death What to do-give magnesium sulphate with charcoal-Activated charcoal, first aid

Signs and symptoms

Abrus precatoris-climbing tree, clusters of small white pink

flowers-flat pod fruit with 2-5 shiny red with black

patch seedsSubtropics, tropics Ricinus communis-large non woody, 3m high large palm like

leaves

Ornamental beans

Round pricky fruits. Bean shaped seed Mottled pink and grey Grown as crop and also scattered in

farmlands Tropics Uses-necklace and rosaries-castor oil beans used to make castor oil

continued

Castor oil used as laxative Seeds are given to children to use in

handicraft and counting and is not recommended

How they cause harm-damage blood cells, gut and kidneysHow poisonous are they?-death, blindness, irritation and rash

uses

If swallowed: effects are delayed for 2hrs to 2 days-burning sensation, sever vomiting, belly pain-Diarrhea with blood, dehydration. Drowsiness-fits ,may pass blood stained urine in small

volumes In the eye-reddening and swelling-sometimes blindness

Signs and symptoms

On skin-Redness and rashWhat to give:Magnesium sulfate, sodium sulfate or

activated charcoal-Wash skin with soap and water-Wash eyes for 15-20mins in running water-Take the seeds out of the mouth

continued

Covers Amanita species1. A. mascaria and A.pantheria cause

hallucinations , sleep or unconsciousness2. A. Phalloides, A. Virosa, A. Verna,

cortinarius speciosissimus and lepiota species contain poisons that damage cells

3. Clitocybe and Inocybe species contain a poison that causes sweating and affects gut

Mushrooms

4. Coprinus atramentarius only causes poisoning when alcohol is taken as well

5. Psilocybe semilanceata and P. Cubensis cause hallucination without sleep

How poisonous they are:-most cause mild to moderate poisoning but

some cause severe poisoning and deathMany people have died after eating

A.phalloides

mushrooms

Identification of poisonous to non-poisonous is very difficult

Cooking may destroy the poison but many kinds like Amanita species are poisonous even after cooking

Sever effects in small children producing fits and unconsciousness

Special danger

dizziness, incordination, stagering hallucinations, deep sleep, muscle jerking

belly pain , nausea, sever vomiting,intense thirst, diarrhea lasting 2-3 days

jaundice, signs of kidney failure,laughing Palpitaions and chest pains,blurred vision Drowsiness,anxiety, red face and neck Metallic taste in the mouth,chills and

headace

Signs and symptoms

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