Persin is a fungicidal

toxin A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849 ...

present in the

avocado The avocado (''Persea americana'') is a medium-sized, evergreen tree in the laurel family ( Lauraceae). It is native to the Americas and was first domesticated by Mesoamerican tribes more than 5,000 years ago. Then as now it was prized for ...

. Persin is an oil-soluble compound structurally similar to a

fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, f ...

, and it leaches into the body of the fruit from the seeds. The relatively low concentrations of persin in the ripe pulp of the avocado fruit is generally considered harmless to humans. Negative effects in humans are primarily in

allergic Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic der ...

individuals. When persin is consumed by domestic animals through the leaves or bark of the avocado tree, or skins and seeds of the avocado fruit, it is toxic and dangerous.ASPCA Poison Control: Avocado
on aspca.org

Pathology

Consumption of the leaves and bark of the avocado tree, or the skin and pit of the avocado fruit have been shown to have the following effects: *In birds, which are particularly sensitive to the avocado toxin, the symptoms are: increased heart rate, myocardial tissue damage, labored breathing, disordered plumage, unrest, weakness, and apathy. High doses cause acute respiratory syndrome (

asphyxia Asphyxia or asphyxiation is a condition of deficient supply of oxygen to the body which arises from abnormal breathing. Asphyxia causes generalized hypoxia, which affects primarily the tissues and organs. There are many circumstances that can ...

), with death approximately 12 to 24 hours after consumption. *Lactating rabbits and mice: non-infectious mastitis and

agalactia In breastfeeding women, low milk supply, also known as lactation insufficiency, insufficient milk syndrome, agalactia, agalactorrhea, hypogalactia or hypogalactorrhea, is the production of breast milk in daily volumes that do not fully meet the nu ...

after consumption of leaves or bark. *Rabbits: cardial

arrhythmia Arrhythmias, also known as cardiac arrhythmias, heart arrhythmias, or dysrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. A resting heart rate that is too fast – above 100 beats per minute in adult ...

, submandibular

edema Edema, also spelled oedema, and also known as fluid retention, dropsy, hydropsy and swelling, is the build-up of fluid in the body's tissue. Most commonly, the legs or arms are affected. Symptoms may include skin which feels tight, the area ma ...

and death after consumption of leaves. *Cows and goats: mastitis, decreased milk production after consumption of leaves or bark. *Horses: clinical effects occur mainly in mares, and includes noninfectious mastitis, as well as occasional gastritis and

colic Colic or cholic () is a form of pain that starts and stops abruptly. It occurs due to muscular contractions of a hollow tube (small and large intestine, gall bladder, ureter, etc.) in an attempt to relieve an obstruction by forcing content out. ...

. *Cats, dogs: mild stomach upset may occur, with potential to cause heart damage. *Hares, pigs, rats, sheep, ostriches, chickens, turkeys and fish: symptoms of intoxication similar those described above. The lethal dose is not known; the effect is different depending upon the animal species. *Mice: non-fatal injury to the lactating

mammary gland A mammary gland is an exocrine gland in humans and other mammals that produces milk to feed young offspring. Mammals get their name from the Latin word ''mamma'', "breast". The mammary glands are arranged in organs such as the breasts in ...

from 60 to 100 mg/kg Persin.

Necrosis Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated diges ...

of myocardial fibres with 100 mg/kg Persin. 200 mg/kg lethal.

Additional pharmacology

Animal studies show that exposure to persin leads to

apoptosis Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes ( morphology) and death. These changes in ...

in certain types of

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or ...

cells. It has also been shown to enhance the

cytotoxic Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa''). Cell physiology Treating c ...

effect of tamoxifen ''

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called " test-tube experiments", these studies in biology a ...

''. Persin is however highly insoluble in aqueous solutions and more research will be needed to put it into a soluble tablet form.

References

{{reflist, 30em Plant toxins Veterinary toxicology Acetate esters