Mechanism of toxicant action.

1. K.G.Arts And science college raighrh
(C.G.)
Class - m.sc 1 sem.( zoology)
Subject- Ecology And Environmental Physiology
Seminar topic - toxicity and taxicants
Mechanism of action
Session - 2021- 2022
Guided by. Sumitted by
Prof. Vinita pandey mam Name- lilima bhardwaj
class- m.sc 1 sem ( zoology)

2. Toxicity and toxicant and mechanisms of action
• Synopsis – 1 introduction
2 Definition
3 History of toxicity
4 types of toxicity
5 toxicology
6 Environmental behaviour factors
7 Toxicant
8 classification of toxicants
9 factors affecting toxicity

3. 10 Route and rate of administration
11 Dose and effect relationship
12 functions of toxicity
13 conclusion
14 Reference

4. 1 Introduction- Toxicity is a relative properties of chemical or its
potential to have a harmful effect on a living organism .toxicity of
chemical may be defined as the capabilities to cause injury in a
living organism.
A highly toxic substance is that which causes damaged to causes
an organism if administrade in a very small amount but a
substrate of toxicity will not produced an effect unless the
amount is very large.

5. 2 Definition – Toxicity is an inherent potential or
capacity of a material to cause adverse effects in a living
organism.
To degree to which a subtances ( a toxin or poison) can
harm human or animal damage an organism before
toxicity can develop a substance must came into contact
with a body surface such as skin,eyes mucosa of the
alimentary or respiratory tract.

6. History – In this science history has been divided into 4
important periods.
1 Aancient period – to hunt our ancestors Our unlike war
tushan poison and arrows or spears used to throw it out It is
found in history and archeology.
2 Middle age – For the fine to the fifteenth century details
information of available recording various types of
poisons.petro di Abano who was a teacher at paduan
university wrote n book on poisons Which yielded 14 voluems.

7. • 3 The Renaissance – paraceisus who died Is 1541 gave detailed
information on the dosage effect concept and treatment of
toxicon.
• 4 moder period – M.J.B. Orfila ( 1789- 1853) wrote the first
comprehensive book on the side effect on chemicals invention
was given the same place as other science branches by him.He
noted definite distinction in dinical forensic and anlytical
invention many of the method propounded by him are still in
use today.

8. • Types of toxicity ~ reaction base –
Acute toxicity - Acute toxicity described the adveres effect of
substance that result either from a single exposure from the
maltiple exposure in the sort period of time ( usually less than 24
hours) to be described as acute toxicity the advers effect should
Occur whitin 14 days Of the administration of the substance.
• Acute effects usually within(24 to 27 ) hours after exposure
however sould occur within 14 days occur exposure.may be as
serious death or temporary as drunkeness.

9. • 2 chronic – effect manifest several months or years after
exposur.may have been an Isolated exposur Or repeated our
many year.
• 3 Local – Action Of toxic substance On specific area of
contact such a skin mucous membranes eyes,throat.
4 Systemic – effect or action is distribution through the body
inhalation of chloroform effect the brain.

10. • toxic agent is anything can Produce an adverse biological
effect.may be chemical physical biological in from example
toxic agent may be chemical ( such as cyadine) Physical
biological ( such as snake venom).
• Toxicology – Toxicology is made up two important words
Toxic and logus .
Toxic – poison
Logus – study
If was collaborate these 2 words then there meaning will be as- the
branch of science which involve the study of toxicity its unwanted
effects its possible of route of administration and their treatment.

11. • Toxicology is the quantitative and qualitative study of adverse and
toxicts effects of chemical Antropogenic material or xenobiothis
environmental chemical on organisms
Toxicant – a toxicant in any toxic substance.toxicant can be poisonous
and they may be man made and naturally Occuring.in contrast in toxin
in poison producted nuturlly by an organism.The different type on
toxicants can be found in the Air, soil, water , or food.

12. • Classification or types of toxicants –
• There are 4 types of toxicants
• 1 Corrosive toxicant
• 2 Irritant
• Systemic
• Me
• 1 Corrosive – corrosive poisons are those that are stabilized on the surface
they come in contact with uprooting the surface it acts by expelling water
from tissue and accumulates cellular proteins and converts hemoglobin to
haematin.

13. ( a) strong acids – 1 mineral or inorganic acid – sulphuric acid,nitric
acid, hydrochloric acid etc.
2 organic acid- oxalic acid corbolic acid Acetyl salicylic acid.
( b) strong alkalies – sodium potassium,Ammonia hydrates and
corbonates.
( c) mechanical – powdered glass diamonds dust and hair.
2 Irritants – irritant toxicant is produced inflammation of the part with
which they comes in contact but do not as a rule destroy the tissue.

14. ( A) inorganic- 1 non metalic – phosphorus chlorine bromine and iodine
etc.
2 metalic- Arsenic , Antimony mercury copper lead zine and slivers.
( b) organic – 1 vegetable- castor , croton,calotropis and Aloes
2 aminal snakes ,insects canthorides , ptomines.
( c) mechanical – powdered glass diamonds duct and hair.
3 systemic – this toxicants effect in the our body many types-
A ) cerebral- somniferous Opium, birthrates.

15. Inebriant – alcohol , ether and chloroform
Deliriant – Daura,baladonna,hyocyamus cannaabis.
( B) Spinal – nux vomica,gelsemium
(c) Cardiovascular – Aconite,quinine,oleander and tabacco
( d) Asphyxiants- co2 co H2s
4 miscellaneous- food poisoning botulism food poisoning include all
disturbance caused by ingestion of food which contain bacteria or
other componets.

16. Factors affecting toxicity
• Host factors
• ( A ) size or body weight – The size or body weight of an individual
determine the dose of a chemical agent required eliciting a given
response metabolism is proportional to body surface area.justly
example the child in highly affected of toxic comparison to youngest.
• (B ) Age – Human infant are usually susceptible to chemical/drug
these are reluted to metabolism ( oxidative pathway) and excretion
pattern immaturity of kindney, brain and deficiency of some key
enzyme like glucuronyl transferase activity result enhanced toxicity

17. • (C) sex – sex hormone influence enzyme of bio transformation of a
compound female have small size and hence lower dose of drug and
chemical required they aye susceptible at pregnancy also.
• ( d) nutrition- high fat diet make organism sensitive to toxicant high
carbohydrates or protein diet make the organism less sensitive
(hepatotoxic effect affecting kidney affecting brain nervous system.
• (E) change in internal environment- Physiology factor such as
physical activity stress condition influence toxicity of a compound.

18. Route and rate of administration
The root carries the toxic substance/ chemicals to the blood
stream is important the lethality of the toxic substance
chemical is dependent on the route of administration
normally the following three routes are used to determine the
mediam lethal dose.
1 oral route
2 dermal route
3 inhalation route

19. Environment / behavior factor
• 1 ) The attitude of the animal man can influence the toxic
response to drug/ toxic chemical.
• 2) presence of other male / female individual of the same
species can affect toxic reaction to certain chemical due to
fear aggression emotion.
• 3) physical factors like light temperature influence the
organism to drug/ chemical Dry condition and worm.hamid
condition may response of the animal/ man.

20. Dose
• It specific the amount of chemical administered per unit body weight
the administration rout l.e. Stomach respiratory tract intramuscular /
intravenous/ transport across the membrane may be incomplete and
the absorbed dose will not be identical with the dose administerd
• The dose in the orgenizational tissue msy be estimated by
• 1) Administrade dose or intake
• 2) measurements of the concentration in tissue orgenisation sample
and
• 3) measurements of concentration in excreta of exhaled air.

21. Dose effect Relationship
• 1 ) quantitative type which relates the dose of a chemical to the dose
of a chemical to the size of the response in a single biological unit.
• 2) the quantal or all none type in which the relationship is between
the dose of the chemical and the proportion of biological objects
displaying a given response.

22. • Celling effect – The degree of effect produce by increasing dose of a
chemical or drug will ultimately reach a steady level called celling
effect Doses beyond the celling effect do not produce any further
effect Rather such as a dose produced undiserable response.
• Quantal response – minimum dose that produced a given effect in a
population of biological object is called quantle response.
The distinct phase
Phase 1 – Time of onsent action administration of a chemical agent to
the system delay in time before the effect is manifested ( lag phase has
a ginti time) for chemical the lag phase may be very small

23. • Phase 2 – time to peak effect chemical has reached even the most
tolerant cell and in accessible cell.
• Phase 3 ( tc) – Duration of action depends upon the rate at which it is
metabolismor inactive or removed from the body.
• Phase 4 ( Tb) – Residule effect many
Chemical exert a residue action even
After primary action is over.

24. Mechanisms of toxicant Action
(1) The effect of toxicant result from their interaction with certain
receptor of the organism
(2) Any functional macromolecules components can serve as toxicant
drug receptor.
(3) Some exogenous molecule are called agonist at these molecule
mimic some of the effect of endogenous substance due to their
interaction with some physiological receptor.
(4) Certain substance may not have endogenous regulatory activity but
theý complete with agonist for binding to receptor or specific
site.these substances are called antagonist.

25. (5) The binding of substance with receptor involved all kind of
interactions lonic,hydrogen hydrophobic,vander waal ‘s and covalent
bonding.
(6) Most of the exogenous substance like drug bind with their receptor
very loosely.
(7) Since these bonding are weak the interaction are reversible in case
of covelant binding the duration of interaction is prolonged
(8) Some exogenous substance like organophosphate and carbamate
Pesticide have structural similarities with acetylcholine
neatrotransmitters these pesticides inhibit ache activety
(9) If choline receptor are blocked by some pesticide these blocking
may affect function controlled by peripheral nerve.
(10) Some exogenous substance may effect controll system in brain.

26. Functions of toxicity
Systemic toxicity means toxicity al a cell level that causes the organ to
fail with the possible death of the organism Toxic substances enter an
organism through the skin oral dermal inhaled roots due to which toxic
and organism come in contact with each other when toxic substances
come in contact with the organism the organism gets harm and disease
which affects the function of many body parts.

27. Conclusion
The toxicant has very harmful of the our body in deffected many
invironmental pollutants or toxic chemical in the environment ot lethal
level or causing harmful effect on living systems.

28. Reference
• 1 ) m.c. dass
• 2) net platform