Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5217_Библиотеки_им_академика_М_И_Перельмана.pdf
Chapter 3 Challenges encountered in growing medicinal and aromatic plants 153
[163] Yaniv, Z. and Bachrach, U., (eds.) (2005). Handbook of Medicinal Plants, CRC Press, Binghamton, NY.
[164] Yoneda, Y., Shimizu, H., Nakashima, H., Miyasaka, J. and Ohdoi, K. (2017). Effects of light intensity
and photoperiod on improving steviol glycosides content in Stevia rebaudiana (Bertoni) Bertoni
while conserving light energy consumption. Journal of Applied Research on Medicinal and Aromatic
Plants, 7, 64–73.
[165] Zhang, S., Zhang, L., Zou, H., Qiu, L., Zheng, Y., Yang, D. and Wang, Y. (2021). Effects of light on
secondary metabolite biosynthesis in medicinal plants. Frontiers Plant Science, 12, 781236.
[166] Zhu, Z., Bao, Y., Yang, Y., Zhao, Q. and Li, R. (2024). Research progress on heat stress response
mechanism and control measures in medicinal plants. International Journal of Molecular Sciences,
25, 8600.
[167] Marimuthu, T., Suganthy, M. and Nakkeeran, S. (2018). Common pests and diseases of medicinal
plants and strategies to manage them. In: Singh, B. and Peter, K. V. (Eds.) New Age Herbals:
Resource, Quality and Pharmacognosy, Springer, Singapore, 289–312. https://doi.org/10.1007/978981-10-8291-7
[168] Carrubba, A., Lo Verde, G. and Salamone, A. (2015). Sustainable weed, disease, and pest
management in medicinal and aromatic plants. Medicinal and Aromatic Plants of the World:
Scientific, Production, Commercial and Utilization Aspects, 205–235.
[169] Sergeeva, V. (2015). Medicinal plants to control diseases and pests. In: Máthé, Á. (Eds.) Medicinal
and Aromatic Plants of the World: Scientific, Production, Commercial and Utilization Aspects,
Springer, Dordrecht, 257–271.https://doi.org/10.1007/978-94-017-9810-5
[170] Pandey, R. and Hembra, S. Pests and diseases of some commercial medicinal and aromatic plants
and their management. In: Gopal, S., Bhat, J. A., Das, A. P. and Sumit C. (Eds.) Bioprospecting of
Ethnomedicinal Plant Resources, Apple Academic Press, New York, 1st edition 2025, 375–397.
https://doi.org/10.1201/9781003451488.
[171] Rajan, V. P. (2003). Insect Pests of Selected Medicinal Plants: Bionomics and Management (Doctoral
Dissertation, Department of Agricultural Entomology, College of Horticulture, Vellanikkara.
[172] Pandey, V., Bhatt, I. D. and Nandi, S. K. (2019). Environmental stresses in Himalayan medicinal
plants: Research needs and future priorities. Biodiversity and Conservation, 2019(28), 2431–2455.
[173] Kala, C. P. (2009). Medicinal plants conservation and enterprise development. Medicinal. Plants-
International Journal of Phytomedicines and Related Industries, 1(2), 79–95.
[174] Ahmed, N., Alam, M., Saeed, M., Ullah, H., Junaid, M., Kanwal, M. and Ahmed, S. (2024). Role of
plants in managing diseases. In: Öztürk, M., Ramaiah Sridhar, K., Sarwat, M., Altay, V., and HuertaMartínez, F. M. (Eds.) Ethnic Knowledge and Perspectives of Medicinal Plants. Apple Academic Press,
New York, 1 st edition. 579–604. https://doi.org/10.1201/9781003353089.
[175] Dwiastuti, M. E., Aji, T. G., Devy, N. F. and Hardiyanto, H. (2024). Prospects of medicinal plants to
control citrus and other subtropical fruits postharvest diseases in Indonesia. In: Proceedings of the
1st International Conference On Food and Agricultural Sciences (ICFAS) 2022: Advanced Agricultural
Technology to Deal with Climate Change Issues for Achieving Food Security, 24–25 November 2022,
Bogor, Indonesia AIP Conference Proceedings , 2957, No. 1 AIP Publishing.
[176] Yetgin, A. (2024). Investigating medicinal plants for antimicrobial benefits in a changing climate.
International Journal of Secondary Metabolite, 11(2), 364–377.
Nuraniye Eruygur✶ and Sanem Hoşbaş Coşkun
Chapter 4
Medicinal and aromatic plants that are toxic
Abstract: Toxic plants and the compounds they produce pose a significant health threat
to both humans and animals. Many plants contain naturally occurring toxins that,
while offering survival advantages to the plants, can lead to a range of harmful effects
in humans when ingested, touched, or inhaled. These toxins can vary widely in their
potency and the severity of their effects, ranging from mild symptoms such as nausea,
vomiting, and skin irritation, to life-threatening conditions such as organ failure, respiratory distress, and even death. This chapter provides an in-depth exploration of some
of the most notorious toxic plants, including oleander, castor bean, aconite, deadly
nightshade, and tobacco, detailing the specific toxic compounds they contain and their
effects on human health. For example, oleander contains cardiac glycosides that can
cause fatal arrhythmias, while castor bean produces ricin, one of the most potent toxins
known, capable of causing organ failure even with minimal exposure.
In addition to examining these plants, the chapter highlights the importance of recognizing toxic species in the environment and understanding the risks they pose. Effective prevention begins with education on plant identification and the implementation of
safe practices for handling these plants. It discusses practical precautions such as wearing protective clothing, including gloves and long sleeves, when handling or gardening
near potentially toxic species, and ensuring that toxic plants are stored and disposed of
safely, out of reach of children and pets. Additionally, the chapter addresses the need for
prompt medical intervention in cases of poisoning, emphasizing the importance of quick
response, such as administering activated charcoal or using specific antidotes when
available. The chapter further explores the role of awareness in reducing risks, stressing
the need for community education on the identification of toxic plants in local environments and gardens. Public awareness campaigns can help prevent accidental exposure,
which is especially important for households with children or pets. Finally, the chapter
underscores the necessity of first aid knowledge, including recognizing the symptoms of
poisoning and the immediate steps to take until professional medical help arrives.
In conclusion, the chapter emphasizes that while toxic plants are a natural part
of the environment, with the right precautions, education, and preparedness, the
risks they present can be significantly minimized. By fostering a deeper understanding of these plants and their harmful effects, we can create safer spaces for people
and animals to coexist with the natural world. The balance between enjoying the
✶
Corresponding author: Nuraniye Eruygur, Department of Pharmacognosy, Faculty of Pharmacy,
Selcuk University, 42250 Konya, Turkey, e-mail: nuraniye.eruygur@selcuk.edu.tr, https://orcid.org/00000002-4674-7009
Sanem Hoşbaş Coşkun, Kelly Government Solutions, Bethesda, ABD
156 Nuraniye Eruygur and Sanem Hoşbaş Coşkun
beauty and benefits of plants and protecting oneself from their toxic effects is critical
for maintaining public health and safety.
Keywords: Secondary metabolites, natural toxins, alkaloids, phytotoxins
4.1 Introduction
Plants have been used for both medicinal and aromatic purposes throughout human
history. However, some plants, in addition to their healing effects, can be dangerous if
not handled with care due to the toxic compounds they contain. In this section, the
properties, uses and potential risks of some medicinal and aromatic plants known to
be toxic will be examined.
4.2 Toxic compounds and their effects
Poisonous plants are characterized by substances such as alkaloids, glycosides, and
essential oils. These substances can cause various biochemical reactions in the body,
resulting in both beneficial and harmful effects (Table 4.1). For example, while digitalis (foxglove) is used in the manufacture of medicines for heart disease, it can be
fatal in the wrong dosage. While medicinal and aromatic plants offer a range of therapeutic benefits, their toxic compounds must be handled with care. These bioactive
chemicals, such as alkaloids, glycosides, essential oils, saponins, and coumarins, can
provide healing effects in controlled doses but become dangerous when misused.
Therefore, proper dosing, professional guidance, and awareness of potential side effects are essential in the safe use of these plants.
4.2.1 Alkaloids
Alkaloids are nitrogen-containing compounds that can have strong physiological effects on humans. Many medicinal plants contain alkaloids that, in controlled doses,
can have therapeutic effects, but in higher concentrations, they may become toxic. Atropine (from Atropa belladonna): used in medicine to dilate pupils and treat bradycardia (slow heart rate). However, excessive intake can cause hallucinations, seizures,
coma and even death [1]. Nicotine (from Nicotiana tabacum): a stimulant found in tobacco that can cause addiction. In large doses, nicotine poisoning can lead to nausea,
increased heart rate, paralysis or respiratory failure, and death [2]. Morphine (from
Papaver somniferum): apowerful pain reliever derived from the opium poppy, but addiction and overdose can lead to respiratory depression and death [3].
Chapter 4 Medicinal and aromatic plants that are toxic 157
Table 4.1: Toxic phytochemicals according to their secondary metabolite groups, showing their plant
origin and toxic effects.
Secondary
metabolite group
Alkaloids Atropine Atropa belladonna
Glycosides Digoxin Digitalis purpurea
Proteins (toxins) Ricin Ricinus communis (castor
Terpenoids Aconitine Aconitum spp.
Phenolic compounds Cicutoxin Cicuta spp. (water
Saponins Ginsenosides Panax spp. (ginseng) High doses can cause vomiting,
Cyanogenic
glycosides
Phytochemical
compound
Strychnine Strychnos nux-vomica
Coniine Conium maculatum
Amandin Prunus spp. (bitter
Abrin Abrus precatorius (rosary
Amygdalin Prunus spp. (bitter
Plant origin Toxic effects
(deadly nightshade)
(nux vomica)
(hemlock)
(foxglove)
almonds)
bean)
pea)
(monkshood,
wolfsbane)
hemlock)
almond and cherry)
Dry mouth, blurred vision,
hallucinations, and death in high
doses
Muscle spasms, convulsions, and
death from respiratory failure
Respiratory paralysis and death
Cardiac arrhythmias, heart failure,
and death
Cyanide poisoning causing
respiratory distress and coma
Inhibits protein synthesis, organ
failure, and death
Similar to ricin, inhibits protein
synthesis, and fatal in small doses
Nausea, vomiting, cardiac arrest,
and death
Seizures, vomiting, respiratory
failure, death
diarrhea, and toxicity
Cyanide release, respiratory failure,
and death
4.2.2 Glycosides
Glycosides are molecules that consist of a sugar and another functional group, often a
toxic compound. They are often found in medicinal plants, particularly those used for
heart conditions. Digitalis glycosides (from Digitalis purpurea): used to treat heart conditions like atrial fibrillation. While therapeutic in low doses, an overdose can lead to
life-threatening cardiac toxicity, arrhythmias, and cardiac arrest. Digitalis glycosides
strengthen the heart muscle but can be lethal in overdose [4]. Cyanogenic glycosides
(from Prunus species like cherry and apricot): release cyanide when metabolized,
158 Nuraniye Eruygur and Sanem Hoşbaş Coşkun
which can inhibit cellular respiration and lead to poisoning [5]. The toxic effects of
cyanogenic glycosides are rapid breathing, seizures, and death. Fresh, cyanophoric
plant materials have higher amounts of glycosides than processed foods that are often
fed to pigs and poultry. Certain plants have the ability to collect high amounts of cyanogenic glycosides, which when consumed, turn into prussic acid. When stressed,
stunted plants start to develop after drought breaks the danger of prussic acid toxicity
in animals is significantly elevated. A powerful toxin, prussic acid enters an animal’s
circulation and travels throughout its body after consumption. The animal then dies
from hypoxia as a result of the disruption of the mitochondria’s electron transport
chain (ETC), which prevents the use of oxygen [6].
4.2.3 Essential oils
Essential oils of some plants are used in aromatherapy but can be toxic in large quantities. Essential oils are highly concentrated plant extracts that contain volatile compounds. While they are used for therapeutic purposes such as in aromatherapy, some
can be toxic if ingested or used improperly. Thujone (from Artemisia absinthium –
wormwood): Known for its presence in absinthe. In large amounts, thujone can cause
convulsions, seizures, neurological damage, hallucinations, and even brain damage
[7]. Eugenol (from Syzygium aromaticum – cloves): commonly used for dental pain relief. However, eugenol in high doses can cause liver toxicity [8]. The essential oils like
cinnamon oil or clove oil have effects of skin irritation and allergic reactions.
4.2.4 Saponins
Saponins are naturally occurring glycosides found in many plants. They have a soaplike property when mixed with water, and some can be toxic when ingested. Solanine
(from Solanum species like potatoes and tomatoes): Solanine is a toxic glycoalkaloid
found in green potatoes and can cause gastrointestinal irritation, diarrhea nausea,
vomiting, and even death if consumed in large amounts. It can also lead to hemolysis
(destruction of red blood cells) in extreme cases [9].
4.2.5 Coumarins
Coumarins are plant-derived chemicals that have anticoagulant properties, while
some are used in medicine (like warfarin). Toilet soap and detergents, toothpaste, tobacco products, and some alcoholic drinks all contain coumarin, which is utilized as a
fixative and enhancing factor in fragrances [10]. They can be toxic in large quantities.
Dicoumarol (from Melilotus species): Found in spoiled sweet clover, it can lead to ex-
Chapter 4 Medicinal and aromatic plants that are toxic 159
cessive bleeding and internal hemorrhage when ingested in large amounts. Primary
lymphedema and lymphedema brought on by radiation therapy or surgery for breast
cancer can both be effectively treated with coumarin. However, because of the potential for hepatotoxicity, which primarily manifests as mild to moderate transaminase
increase, its clinical usage is restricted in a number of countries [11].
4.3 Poisonous medicinal plants
Throughout history, many poisonous plants have also been utilized for their medicinal properties. While they can provide significant health benefits when used correctly
and in controlled doses, their toxic nature makes them potentially dangerous when
misused. Poisonous medicinal plants such as Digitalis, Atropa belladonna, Aconitum,
Conium, and Nerium oleander serve as a reminder that many plants hold both healing
and dangerous properties (Table 4.2). While their toxic components can be beneficial
in controlled medical use, their potential to cause harm, even in small amounts, necessitates careful handling, professional oversight, and clear public awareness. This
section explores some of the most well-known poisonous medicinal plants, their uses,
and their potential risks.
Table 4.2: Some common medicinal and aromatic plants that are known to be toxic, along with their
potential toxic compounds and symptoms of toxicity.
Plant name Toxic
compounds
Atropa belladonna Tropane alkaloids
(e.g., atropine
and scopolamine)
Aconitum (monkshood) Aconitine
alkaloids
Digitalis purpurea Cardiac
glycosides (e.g.,
digoxin)
Nerium oleander Oleandrin
(cardiac
glycoside)
Symptoms of toxicity Notes
Dilated pupils, blurred
vision, tachycardia, dry
mouth, urinary retention,
seizures, and death in
extreme cases
Nausea, vomiting,
abdominal pain, dizziness,
arrhythmia, respiratory
failure, and death
Vomiting, diarrhea, heart
arrhythmias, confusion,
dizziness, and death
Vomiting, diarrhea,
bradycardia, arrhythmia,
heart block, and death
Highly toxic, especially when
consumed in large
quantities; historically used
as a poison and in medicine
for certain conditions
Used in traditional medicine,
but highly toxic; even small
doses can be fatal
Widely used in heart
treatment, but overdose can
cause severe cardiac toxicity
All parts of the plant are
highly toxic, especially when
ingested
160 Nuraniye Eruygur and Sanem Hoşbaş Coşkun
Table 4.2 (continued)
Plant name Toxic
compounds
Ricinus communis Ricin, a highly
toxic protein
Conium maculatum Coniine, an
alkaloid
Taxus baccata (yew) Taxine alkaloids Nausea, vomiting, dizziness,
Hyoscyamus niger Tropane alkaloids
(e.g.,
hyoscyamine)
Cicuta virosa
(water hemlock)
Silybum marianum
(milk thistle)
Lavandula stoechas Camphor and
Ruta graveolens
(rue)
Toxicodendron radicans
(poison ivy)
Cicutoxin Seizures, respiratory
Silymarin (in
large doses)
thujone
Furanocoumarins
(e.g., rutin)
Urushiol (a resin) Skin irritation, rashes,
Symptoms of toxicity Notes
Abdominal pain, vomiting,
diarrhea, organ failure, and
death
Drooping eyelids, dilated
pupils, weakness, respiratory
failure, and death
difficulty breathing, and
death
Dilated pupils, tachycardia,
dry mouth, confusion,
hallucinations, and seizures
distress, vomiting,
convulsions, and death
Gastrointestinal distress,
nausea, vomiting, and
allergic reactions
Dizziness, seizures,
confusion, respiratory
issues, dermatitis, and
neurotoxicity in excessive
use
Skin irritation,
photosensitivity, nausea,
vomiting, and liver damage
itching, and blisters
Castor bean plant, highly
toxic when seeds are
ingested; ricin is one of the
strongest known poisons
Also known as poison
hemlock; historically used as
a poison in executions
Extremely toxic; every part of
the plant is poisonous, with
the exception of the red arils,
which comprise the fruit’s
fleshy portion
Known as henbane; used in
folk medicine, but toxic at
higher doses
Ingestion of any part of the
plant can be fatal
Typically used for liver
health; large doses can
cause adverse effects
Camphor is toxic in high
amounts, especially when
ingested or applied topically
in large doses
Toxic when ingested in large
quantities or applied directly
to the skin
Causes contact dermatitis
upon exposure to the resin
found in the plant
4.3.1 Digitalis purpurea (foxglove)
Foxglove contains cardiac glycosides, primarily digitoxin and digoxin. These compounds affect the sodium-potassium balance in heart cells, leading to stronger heart
Chapter 4 Medicinal and aromatic plants that are toxic 161
contractions. Foxglove has been used for centuries as a heart tonic in folk medicine.
Digoxin, derived from foxglove, is used to treat certain heart conditions, such as heart
failure and atrial fibrillation. It increases the force of heart contractions and slows
down the heart rate [12].
Symptoms of poisoning include nausea, vomiting, diarrhea, confusion, visual disturbances (seeing halos or blurred vision), and potentially fatal heart arrhythmias. Ingesting a small amount of the plant can be lethal if not treated immediately [4]. Cardiac glycosides have been a key component in the therapy of congestive heart failure
since William Withering’s dissertation on the efficacy of the leaves of the common
foxglove plant (Digitalis purpurea) in the late eighteenth century codified its use. The
effectiveness and safety of this class of medications are still up for the question, despite their broad adoption into medical practice during the next 200 years. Furthermore, although the molecular target for the cardiac glycosides – the α-subunit of sarcolemmal Na
membranes – has been known for several decades, it is still unclear whether the sympatholytic or positive inotropic effects of these agents are the mechanisms most relevant to alleviating heart failure symptoms [13].
+-K+
-ATPase (or sodium pump) found on most eukaryotic cell
4.3.2 Atropa belladonna (deadly nightshade)
Atropa belladonna contains tropane alkaloids, mainly atropine, scopolamine, and hyoscyamine. These alkaloids act as anticholinergics, blocking acetylcholine receptors in
the nervous system. Historically, belladonna was used in Italy to dilate women’s pupils
(hence the name “beautiful lady” or “belladonna”). Atropine, extracted from bella-
donna, is used in medicine as a muscle relaxant, to treat bradycardia (slow heart
rate), and as an antidote for certain types of poisonings (such as organophosphates).
Scopolamine is used for motion sickness and postoperative nausea. Toxic effect symptoms include dry mouth, blurred vision, difficulty swallowing, confusion, hallucinations, seizures, and respiratory failure. Death can occur if large quantities are ingested. As little as 10–20 berries can be fatal for adults, while even fewer are deadly
for children [14].
4.3.3 Aconitum napellus (monkshood, aconite)
Aconitine and related alkaloids are found in the Aconitum species, a potent neurotoxin and cardiotoxin. Aconitine interferes with sodium channels in nerves and
muscles, leading to abnormal electrical activity. The wild plant is highly hazardous,
particularly the roots and root tubers. Accidental eating of the wild plant or ingestion
of a herbal decoction prepared from aconite roots can result in severe aconite poisoning. Aconite roots are only utilized in traditional Chinese medicine after being proc-
162 Nuraniye Eruygur and Sanem Hoşbaş Coşkun
essed to lessen their harmful alkaloid content. Aconite alkaloids will be hydrolyzed
into less toxic and nontoxic derivatives by soaking and boiling during processing or
decoction production. However, the danger of poisoning is increased by using a dose
that is higher than is advised and by improper processing [15]. Historically, aconite
was used in traditional Chinese medicine for its analgesic and anti-inflammatory
properties. It was also applied topically to treat joint pain and rheumatism. Some
components of aconite are still used in modern Chinese herbal medicine in highly regulated, detoxified forms for pain relief and inflammation [16]. The toxic effect symptoms of aconitine poisoning include tingling or numbness of the face and limbs, vomiting, diarrhea, difficulty breathing, irregular heartbeats, paralysis, and death due to
respiratory or cardiac arrest. Even a small amount of the raw plant (as little as 2 mg
of aconitine) can be fatal.
4.3.4 Conium maculatum (hemlock)
Hemlock contains coniine, a neurotoxin that disrupts communication between the
central nervous system and muscles by blocking nicotinic acetylcholine receptors. In
ancient Greece, hemlock was infamously used as a method of execution, most notably
in the case of the philosopher Socrates [17]. Despite its toxic nature, small amounts
were used in the past to treat muscle spasms and arthritis. Due to its extreme toxicity,
hemlock is no longer used in modern medicine. Toxic effect symptoms include muscle
weakness, paralysis, respiratory failure, and death. The paralysis caused by hemlock
moves from the extremities toward the core, ultimately leading to respiratory failure
as the diaphragm is paralyzed. A very small dose, around 0.5 g of the plant, can be
fatal [18].
4.3.5 Nerium oleander (oleander)
Oleander contains cardiac glycosides, primarily oleandrin and neriine, which have effects similar to those of digitalis. These compounds interfere with the electrolyte balance of heart cells, potentially leading to fatal arrhythmias. Oleander was used in folk
medicine as a treatment for a variety of ailments, including heart conditions and skin
diseases. Some research has explored the use of oleandrin in cancer treatment,
though its extreme toxicity makes this highly experimental. Toxic effects of oleander
poisoning include nausea, vomiting, abdominal pain, dizziness, arrhythmias, and potentially cardiac arrest [19]. Both ingestion and inhalation of oleander smoke can be
fatal. Ingesting one leaf is potentially lethal for an adult, and even small amounts can
kill a child [20].