Subscribe to Email Updates

The influence that toxic substances (toxins) have on symptoms/diseases in the human body



Aconite and other closely resembling alkaloids having a toxic effect on the cardiovascular system and neurocognition are present in Aconitum plant species. People sometimes accidentally ingest this plant roots and tubers that have aconite the toxic material. The toxic effect of aconite is exhibited by its effect on the sodium channels of the cell membrane in tissues of heart, nervous system and certain muscles.

Disruption of sodium channel action leads to changes in the permeability of cells that are associated with the toxic reactions. There is no effective treatment for aconite poisoning except supportive therapies. Sometime cardiopulmonary bypass is recommended under severe aconite toxicity [1, 2]. One has to be careful, and public health personnel has to identify the regions having these plants and proper education of people living in these areas.


Arsenic is a natural element found in smaller quantities in the soil, water, and rock. This element has the capability to combine with other elements forming both organic and inorganic compounds. The inorganic form of arsenic exerts very high toxicity for livings [3]. Water contaminated with arsenic used for drinking, cooking and other purposes pose a grave threat to human health.

Generally, arsenic poisoning has the symptoms of dizziness, vomiting, abdominal pain and diarrhea. If left untreated, the arsenic poisoning leads to several complications that could be fatal also. Long term arsenic exposure among human primarily affects the skin and could result in a variety of complications including cancer, developmental, cardiovascular, neurotoxicity and diabetes [4]. 


This toxin is present in a plant known as Atropa belladonna, a perennial herb growing in tropical and sub-tropical regions of the world [5]. Mainly this herb is found in Europe, North Africa, and Western Asia. The berries and foliage of this plant are highly toxic as they contain tropane alkaloids. Tropane alkaloids are a group of toxins and are present in all parts of Atropa belladonna plant. If it is ingested, it can cause serious side effects.

The berries are the most poisonous part as they might look tempting to kids and if someone consume 1 or 2 seeds of this plant, it can be fatal. Major symptoms associated with Belladonna poisoning are blurred vision, dilation of eye pupil, light sensitivity, rashes, tachycardia, delirium and several others.

Botulinum Toxin

Botulinum toxin is secreted by a bacterium, Clostridium botulinum. This toxin is highly neurotoxic and blocks the release of a neurotransmitter, acetylcholine. Acetylcholine is involved in nerve transmission, and the botulinum mediated blockage of nerve transmission ultimately lead to paralysis and other ailments [6].

This toxin has been used for therapeutic purposes also and proved to be very effective against numerous spastic movement disorders. There is the wider use of this toxin in cosmetic formulation mainly for rectifying aging-associated wrinkles from the face. This toxin is given in the form of injection for its dermatological applications, and it has minimum side effects and is well tolerated [7]. 


Cyanide is a chemical poison and exists in several forms. The characteristic feature of cyanide compounds is the presence of cyano group (Carbon with Nitrogen having three bonds). Several forms of cyanide compounds are like hydrogen cyanide, potassium cyanide, and sodium cyanide. The exposure of cyanide compounds leads to several toxic symptoms like dizziness, headache, breathing problem and nausea, vomiting [8].

The worsening of these symptoms ultimately results in cardiac arrest. Cyanide also stops the utilization of oxygen in human cells. People are exposed to cyanide by inhalation of smoke containing cyanide compounds[9]. High doses of cyanide can lead to immediate unconsciousness and sudden death. Treatment of cyanide poisoning depends on its dose. 

Dimethyl mercury

The dimethyl mercury is an organic form of mercury. It induced a variety of toxicities long term damage to the vision system and several other chronic disorders. People usually ingest this toxin, and it is readily absorbed in the human body [10]. It gets incorporated into the human tissues due to its organic nature and has relatively lesser excretion.

Signs and symptoms of this toxin can be impaired peripheral vision, muscle weakness, hearing and speech impairment, impairment in walking, lack of coordination and disturbed sensations. Methyl mercury has also been reported to damage pancreatic beta cells also thus inducing diabetes [11]. High levels of exposure to this toxin lead to set of complications in the human body known as Minamata disease.


Hemlock is considered as one of the poisonous plants in North America. Toxicity is manifested as respiratory failures and associated symptoms. There are two types of this poison, water hemlock family plants and poison hemlock differing in their toxicity profiles [12, 13]. In both of these plant species the plant roots have the highest concentration of toxin.

Both of them are related however they differ in the presentation of their toxicity. No antidote is available for this toxin. It significantly affects the central nervous system, and it acts by blocking the neuromuscular junction which can lead to death [14, 15]. 


Mercury is chemical element and present in the earth mainly in the form of mercuric sulfide (mercury attached to the sulfur element). This is a widely in several temperatures and pressure measuring equipment like a thermometer, sphygmomanometers, and barometers. Mercury can exist both in water soluble and insoluble form based on the compound it is linked with. The insoluble form mainly mercuric chloride or methyl mercury ingestion or inhalation lead to a variety of toxic responses in the human body.

The symptoms associated with mercury can both be for short term or long lasting and include mood disorders, headache, insomnia, tremors, and weakness due to muscles wasting. The organic form of mercury the methyl mercury toxicities are manifested as vision impairment and loss of body coordination [16]. 


This toxin is naturally present in the seeds of the castor oil plant. It is highly toxic and found in castor beans if these beans are chewed and swallowed then ricin can cause damage [17]. Ricin disrupts cellular machinery of the human body by stopping the necessary protein synthesis required for proper function of cells [17, 18].

This situation leads to apoptosis in cells and cell signaling coordinations. Signs and symptoms of ricin toxicity vary depending upon whether it is inhaled, ingested or injected. If the toxicity of ricin is left untreated for 36 to 72 hours after exposure, it can be fatal. 


This is a potent naturally occurring neurotoxin [19, 20]. Tetrodotoxin toxicity results by the ingestion of contaminated puffer fish mainly consumed in Japan. Studies have shown that Tetrodotoxin producing bacteria are also present in fishes and other animals also as a source of toxin [21]. This toxin has no known antidote. This toxin acts by blocking the sodium channel hence inhibiting the firing of the action potential in neurons.

This block can lead to paralysis of muscles especially respiratory muscles like diaphragm which can cause respiratory arrest and death consequences. According to some studies, this toxin has been associated with relieving cancer associated pain.  

Professor Dr. Muhammad Mukhtar


1. Chan, T.Y., Aconite poisoning presenting as hypotension and bradycardia. Hum Exp Toxicol, 2009. 28(12): p. 795-7.

2. Chan, T.Y., Aconite poisoning. Clin Toxicol (Phila), 2009. 47(4): p. 279-85.

3. Bjorklund, G., et al., Effects of arsenic toxicity beyond epigenetic modifications. Environ Geochem Health, 2017.

4. Sun, X., et al., Arsenic-induced testicular toxicity in Gallus gallus: Expressions of inflammatory cytokines and heat shock proteins. Poult Sci, 2017.

5. Golwalla, A., Multiple Extrasystoles: An Unusual Manifestation of Belladona Poisoning. Dis Chest, 1965. 48: p. 83-4.

6. Dimpfel, W. and E. Habermann, [Neurotoxic actions of Clostridium tetani and botulinum toxins (proceedings)]. Zentralbl Bakteriol Orig A, 1976. 235(1-3): p. 104-5.

7. Carruthers, J. and A. Carruthers, Botox: beyond wrinkles. Clin Dermatol, 2004. 22(1): p. 89-93.

8. Tshala-Katumbay, D.D., et al., Cyanide and the human brain: perspectives from a model of food (cassava) poisoning. Ann N Y Acad Sci, 2016. 1378(1): p. 50-57.

9. Cohen, M.A. and L.J. Guzzardi, Toxic smoke inhalation and cyanide poisoning. Am J Emerg Med, 1988. 6(2): p. 203-5.

10. Chapman, L. and H.M. Chan, The influence of nutrition on methyl mercury intoxication. Environ Health Perspect, 2000. 108 Suppl 1: p. 29-56.

11. Schumacher, L. and L.C. Abbott, Effects of methyl mercury exposure on pancreatic beta cell development and function. J Appl Toxicol, 2017. 37(1): p. 4-12.

12. Konca, C., et al., Hemlock (Conium Maculatum) Poisoning In A Child. Turk J Emerg Med, 2014. 14(1): p. 34-6.

13. Schep, L.J., et al., Poisoning due to water hemlock. Clin Toxicol (Phila), 2009. 47(4): p. 270-8.

14. Drummer, O.H., et al., Three deaths from hemlock poisoning. Med J Aust, 1995. 162(11): p. 592-3.

15. Short, J., Water hemlock poisoning. Emerg Nurse, 2006. 14(7): p. 18-9.

16. Branco, V., et al., Biomarkers of mercury toxicity: Past, present, and future trends. J Toxicol Environ Health B Crit Rev, 2017. 20(3): p. 119-154.

17. Smith, M. and M. Hayoun, Toxicity, Ricin, in StatPearls. 2017: Treasure Island (FL).

18. Olsnes, S. and A. Pihl, Treatment of abrin and ricin with -mercaptoethanol opposite effects on their toxicity in mice and their ability to inhibit protein synthesis in a cell-free system. FEBS Lett, 1972. 28(1): p. 48-50.

19. Kasteel, E.E. and R.H. Westerink, Comparison of the acute inhibitory effects of Tetrodotoxin (TTX) in rat and human neuronal networks for risk assessment purposes. Toxicol Lett, 2017. 270: p. 12-16.

20. Lepiarczyk, E., et al., The Influence of Tetrodotoxin (TTX) on the Distribution and Chemical Coding of Caudal Mesenteric Ganglion (CaMG) Neurons Supplying the Porcine Urinary Bladder. Mar Drugs, 2017. 15(4).

21. Magarlamov, T.Y., D.I. Melnikova, and A.V. Chernyshev, Tetrodotoxin-Producing Bacteria: Detection, Distribution and Migration of the Toxin in Aquatic Systems. Toxins (Basel), 2017. 9(5).

Topics: toxins

Professor Dr. Muhammad Mukhtar

Written by Professor Dr. Muhammad Mukhtar

Professor Dr. Muhammad Mukhtar has over 25 years teaching experience in biomedical sciences. Besides teaching, he has a very strong portfolio of academic administration and he is an accomplished researcher in the area of infectious diseases. Dr. Mukhtar received his Ph.D. in Biosciences from the Drexel University of Philadelphia, USA, and also completed a Graduate Certificate in Research Management from Thomas Jefferson University of Philadelphia, USA. He served in various academic/administrative positions in the USA on an outstanding scientist (O-1) visa.