MEDICAL BIOLOGY, HUMAN ANATOMY, PHYSIOLOGY AND PATHOLOGY - Y.I. Fedoniuk 2010

BIOLOGY

CHAPTER 2. BIOGEOCENOTIC LEVEL OF ORGANIZATION OF LIFE AND HUMAN PLACE IN IT

2.6. ORGANISMS POISONOUS TO HUMANS

Toxicity is a widespread phenomenon in living nature, found in Fungi, plants, and animals. Interest in poisonous organisms is no coincidence. It is driven not only by The properties of the poison, which is often highly toxic, but also by its use in the manufacture of Pharmaceuticals.

Poisonous Plants

When ingested by animals or humans, poisonous plants cause poisoning that can lead to severe illness and even death. The highest concentration of poisonous plants is found among angiosperms (families such as Ranunculaceae, Papaveraceae, Liliaceae, Solanaceae, and Euphorbiaceae), though they also occur among gymnosperms, horsetails, and ferns. Human poisoning by toxic plants occurs in various ways, most commonly through the consumption of specific plant Organs (fruits, seeds, roots, rhizomes, and leaves). Some plants (such as mezereon and buttercups) can cause severe Skin Burns upon contact with the bark or flowers. Prolonged inhalation of volatile compounds released by the flowers of bird cherry, magnolia, poppy, or lilies causes symptoms of poisoning in many people, such as headaches and dizziness. Poisoning can also occur through consuming meat and milk from animals that graze on poisonous plants. For example, goats can eat spurge without any toxic effects due to their natural Immunity, yet their milk becomes poisonous. Similarly, chickens can eat the fruits of lily of the valley and deadly nightshade without harming themselves, but the meat of such chickens can cause human poisoning.

Poisoning incidents are especially frequent among humans—predominantly children—who consume poisonous plants that bear morphological similarities to certain cultivated or wild species. For instance, children frequently poison themselves by eating henbane seeds, which resemble poppy seeds, or deadly nightshade fruits, which look like cherries. All parts of these plants contain Alkaloids (atropine, scopolamine, hyoscyamine). Characteristic signs of poisoning include dilated pupils, bright eyes, dry skin, hoarseness, weakened Cardiac Activity, and potential paralysis of the respiratory center. Jimsonweed (datura) causes similar symptoms. Poisoning can result from eating the seeds or simply by children staying close to blooming plants. The seeds of bitter almond, peach, and cherry contain the glucoside amygdalin, which yields hydrocyanic acid—a potent poison. When homemade tinctures made from stone fruits are stored for long periods, the poison leaches into the alcohol. Consuming such beverages leads to severe hydrocyanic acid poisoning, potentially resulting in death. A powerful plant toxin, strychnine, is found in the bark of the South American strychnine tree. Indigenous peoples used this poison (curare) to coat their arrows, causing respiratory arrest and death. In Africa, strophanthus was used for the same purpose. Furthermore, some plants that are not conventionally classified as poisonous can become toxic under certain conditions. For instance, when potatoes are stored for a long time, their tubers turn green and accumulate the toxic glycoalkaloid solanine, which causes digestive disorders, asphyxia, and tachycardia.

It is worth noting that many poisonous plants are also medicinal (such as deadly nightshade, datura, henbane, and lily of the valley). Valuable medications are prepared from extracts of these plants. For example, atropine in specific therapeutic doses is used to treat certain eye conditions (though contraindicated in glaucoma) and as a sedative.