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Ecology

Strychnos nux-vomica is typically found growing on the outskirts of thick forests, near river banks and shorelines. It thrives primarily in loamy or loamy-sandy soil, although it can also be found in lateritic and clayey loam soils. The amount of rainfall it receives on an annual basis can range from 1200-3500 mm.

The toxic fruit is eaten by monkeys and birds, such as the gray langur. It is also commonly eaten by hornbill species.

Pest:

Noctuidae and sphingidae: Larvas feed on leaves of the plant, especially during flowering season. Controlment: spray with 0.1% trichlorfon every 7-10 days for 2-3 times.

Boll weevil: Adults feed on leaves, causes blade notch. Controlment: artificial capture, or spray with 0.1% Fenitrothion.

Brachytrupes: Could break the stem when the plant is in seedling stage. Controlment: kills with bait made by sugar, rice bran and trichlorfon.

Toxicity

It is a major source of the highly poisonous, intensely bitter alkaloids strychnine and brucine derived from the seeds inside the tree's round, green to orange fruit. The seeds contain approximately 1.5 strychnine, and the dried blossoms contain 1.0%. However, the tree's bark also contains brucine and other poisonous compounds. The alkaloids contained can be divided into three different kinds.

1. Normal series, such as strychnine, brucine, isostrychnine

The structure of Isostrychnine. Drawn with chemdraw.

and isobrucine

structure of isobrucine

. Isostrychnine has similar poisonous with strychnine, which is responsible for inhabiting postsynaptic glycine and acetylcholine receptors, causing pain and muscle spasms, whereas isobrucine has the same effect with brucine, which is the same with strychnine. Brucine has similar effects with strychnine, but comparatively less toxic. One reason brucine is less toxic is the position of the double bond in the tetracyclic structure. Strychnine has a double bond between C9 and C10, while brucine has a double bond between C10 and C11. This subtle difference in bonding results in strychnine being more lipophilic (fat-soluble) and more easily crossing the blood-brain barrier, allowing it to affect the central nervous system more readily.

2. Pseudo series, such as pseudo-strychnine

structure of Pseudostrychnine

and pseudobrucine.

structure of Pseudobrucine

Pseudostrychnine is a type of monoterpenoid indole alkaloid that differs from strychnine in that a hydrogen atom at position 16 has been replaced by a hydroxyl group. Its function as a plant metabolite is well-documented. Its chemical structure is similar to that of strychnine, indicating a functional relationship between the two compounds. Pseudobrucine is a monoterpenoid indole alkaloid that shares a structural similarity with brucine, but differs by the replacement of a hydrogen atom at position 16 with a hydroxyl group. This compound is known to act as both a plant metabolite and a human xenobiotic metabolite. The functional relationship between pseudobrucine and brucine is evident from their structural similarity.

3. N-methylpseudo series, such as icajine

structure of Icajine

and vomicine.

structure of Vomicine

Icajine is a type of monoterpenoid indole alkaloidIt was first discovered in the leaves of Strychnos icaja, and is known to act as a plant metabolite as well as a sodium channel blocker, it could also binds to and results in decreased activity of SCN5A protein. Vomicine is a member of carbazoles.

Since brucine, isostrychnine, isobrucine, pseudo-strychnine, pseudobrucine, icajine and vomicine are mainly found in Strychnos nut-vomica, they are often ingested with strychnine. Therefore it is rare that a patient is poisoned by only one of them.

Symptoms of Strychnos nux-vomica poison includes muscle spasms and rigidity, seizures, difficulty breathing, elevated blood pressure, sweating, fever, dilated pupils, nausea and vomiting. Treatment includes inducing vomiting or administering activated charcoal to absorb any remaining poison, management of muscle spasms and seizures, with benzodiazepines or barbiturates and breathing support.

Uses

The strychnine-containing seeds have been used in arrow poison. The use of strychnine is highly regulated in many countries, and it is mostly used in baits to kill feral mammals. Most accidental poisoning is caused by breathing in the powder or by absorption through the skin.

Strychnos is promoted within alternative medicine as a treatment for many conditions, but the claims are not supported by medical evidence.

Herbalism

Bark of Strychnos nux-vomica

Strychnos is promoted within herbal medicine as being a treatment for a wide range of maladies, including cancer and heart disease. There is, however, no evidence it is useful for treating any condition. Indeed, these seeds contain strychnine. The plant appears on the Commission E list of unapproved herbs because it has not been proven to be safe or effective and thus is not recommended for use. Use of strychnine seeds for such purposes may prove fatal as strychnine is a highly toxic compound and has no safe limit for consumption.

In Ayurveda (the Indian system of Classical medicine), hudar is a mixture containing Strychnos nux-vomica. The seeds are first immersed in water for five days and then in milk for two days followed by their boiling in milk.

In China, Strychnos nux-vomica is described as "a tree whose fruit is large, round, and flat with white hair and a bitter taste. The poison in its seeds can cause numbness, spasms, and death in birds, while causing excruciating pain and death from organ failure in dogs. If ingested by humans, it can cause muscle spasms and contractions in the limbs." The seed is used to treat cold and sore throat, as well as refusing swelling lump. It can also be treatment for fracture, facial paralysis, severe myasthenia, sequela of poliomyelitis and cancer.. For ingestion, made into pellet after prepared, take 0.3g~0.6g per day. For external use, grind into powder in water, vinegar or frying oil. The content of alkaloid should be below 0.6mg for each dose. The most effective dose is when the patient has weak muscle cramp, which also means the dose cannot be higher. For safety, it cannot be used freshly, and the dose should be kept low. Pregnant woman should not use it. People with weak digestive system should be more careful when using.

The level of toxic alkaloids in the unprocessed Strychnos seeds used in traditional medicines can be determined using established HPLC methods and HPLC-UV methods.

Pop Culture

Strychnos nux-vomica sometimes appears in Chinese fictions and TV series as a poison called "Qianji".

The name describes people's reaction caused by it. The pain and muscle spasm makes the patient's body bending that his feet and head almost contacted (opisthotonus), like a puppet in puppetry. In Moji , it is described as "after ingesting, body bending for many times, head and feet touch like a puppet". It is saying that the last ruler of Southern Tang state during imperial China's Five Dynasties and Ten Kingdoms period, Li Yu, is killed by Qianji.

In the TV series Ruyi's Royal Love in the Palace, Wei Yanwan died from Qianji.