Neurotoxic Health Dictionary

Neurotoxic: From 1 Different Sources


Neurotoxin

A chemical substance that harms nervous tissue, causing symptoms of numbness or weakness of the body part supplied by the damaged NERVE. The venom of some snakes contains neurotoxic substances, and bacteria may produce neurotoxins: examples are those that cause DIPHTHERIA and TETANUS. Arsenic and lead are examples of inorganic neurotoxins.... neurotoxin

Anís De Estrella

Chinese star anise (Illicium verum).

Plant Part Used: Fruit, seed.

Dominican Medicinal Uses: The fruits or seeds are traditionally prepared as a decoction and taken orally for flatulence, headache, indigestion, stomach ache, upper respiratory tract infection and cleansing the intestines.

Safety: The fruit is generally considered safe for human consumption in small amounts and is widely used as a culinary spice. When taken in excessive quantities, isolated compounds from the fruit have shown neurotoxic effects in animal studies. Caution is advised due to possible adulteration with the highly poisonous look-alike, Japanese star anise (Illicium anisatum).

Contraindications: Avoid use in small children due to potential contamination with misidentified toxic look-alike. Caution and avoidance is advised in patients with a history of convulsive disorders including epilepsy due to case reports of seizures associated with internal use of the tea. Caution advised in patients prior to surgery due to potential risk of increased bleeding.

Drug Interactions: Anticoagulants, antiplatelet medications and NSAIDS: based on animal studies in mice, star anise increases cytochrome P450 dependent 7-ethoxycoumarin O-deethylase activity which may affect the metabolism of these drugs.

Clinical Data: No human clinical trials evaluating this plant species have been identified in the available literature.

Laboratory & Preclinical Data: The following biological activities of this plant have been demonstrated in laboratory and preclinical studies using in vitro or animal models: antiangiogenic, antibacterial, antimicrobial, insecticidal, neurotropic and sepsis prevention.

* See entry for Anís de estrella in “Part 3: Dominican Medicinal Plant Profiles” of this book for more information, including references.... anís de estrella

Bites And Stings

Animal bites are best treated as puncture wounds and simply washed and dressed. In some cases ANTIBIOTICS may be given to minimise the risk of infection, together with TETANUS toxoid if appropriate. Should RABIES be a possibility, then further treatment must be considered. Bites and stings of venomous reptiles, amphibians, scorpions, snakes, spiders, insects and ?sh may result in clinical effects characteristic of that particular poisoning. In some cases speci?c ANTIVENOM may be administered to reduce morbidity and mortality.

Many snakes are non-venomous (e.g. pythons, garter snakes, king snakes, boa constrictors) but may still in?ict painful bites and cause local swelling. Most venomous snakes belong to the viper and cobra families and are common in Asia, Africa, Australia and South America. Victims of bites may experience various effects including swelling, PARALYSIS of the bitten area, blood-clotting defects, PALPITATION, respiratory di?culty, CONVULSIONS and other neurotoxic and cardiac effects. Victims should be treated as for SHOCK – that is, kept at rest, kept warm, and given oxygen if required but nothing by mouth. The bite site should be immobilised but a TOURNIQUET must not be used. All victims require prompt transfer to a medical facility. When appropriate and available, antivenoms should be administered as soon as possible.

Similar management is appropriate for bites and stings by spiders, scorpions, sea-snakes, venomous ?sh and other marine animals and insects.

Bites and stings in the UK The adder (Vipera berus) is the only venomous snake native to Britain; it is a timid animal that bites only when provoked. Fatal cases are rare, with only 14 deaths recorded in the UK since 1876, the last of these in 1975. Adder bites may result in marked swelling, weakness, collapse, shock, and in severe cases HYPOTENSION, non-speci?c changes in the electrocardiogram and peripheral leucocytosis. Victims of adder bites should be transferred to hospital even if asymptomatic, with the affected limb being immobilised and the bite site left alone. Local incisions, suction, tourniquets, ice packs or permanganate must not be used. Hospital management may include use of a speci?c antivenom, Zagreb®.

The weever ?sh is found in the coastal waters of the British Isles, Europe, the eastern Atlantic, and the Mediterranean Sea. It possesses venomous spines in its dorsal ?n. Stings and envenomation commonly occur when an individual treads on the ?sh. The victim may experience a localised but increasing pain over two hours. As the venom is heat-labile, immersion of the affected area in water at approximately 40 °C or as hot as can be tolerated for 30 minutes should ease the pain. Cold applications will worsen the discomfort. Simple ANALGESICS and ANTIHISTAMINE DRUGS may be given.

Bees, wasps and hornets are insects of the order Hymenoptera and the females possess stinging apparatus at the end of the abdomen. Stings may cause local pain and swelling but rarely cause severe toxicity. Anaphylactic (see ANAPHYLAXIS) reactions can occur in sensitive individuals; these may be fatal. Deaths caused by upper-airway blockage as a result of stings in the mouth or neck regions are reported. In victims of stings, the stinger should be removed as quickly as possible by ?icking, scraping or pulling. The site should be cleaned. Antihistamines and cold applications may bring relief. For anaphylactic reactions ADRENALINE, by intramuscular injection, may be required.... bites and stings

Hemerocallis Fulva

Linn.

Habitat: The Himalaya, Khasi Hills; cultivated in Indian gardens.

English: Common Yellow Day-lily, Tawny Day-lily, Orange Day-lily.

Action: Flower—analgesic, especially in child birth; blood purifier. (Flowers are sold in Chinese food shops as Gum-Tsoy or Gum-Jum.)

Hemerocallin, a neurotoxic principle, has been found in Hemerocallis sp. The plant gave amino acid—oxyp- innatanine.... hemerocallis fulva

Lindane

An insecticide used in SCABIES and lice infestations (see PEDICULOSIS); however, head lice are now often resistant. Used excessively, lindane may be neurotoxic (damage the nervous system).... lindane

Sea Snakes

Marine, air breathing reptiles with a potent neurotoxic and myotoxic venom responsible for many deaths world-wide - although there are no documented deaths in Australia. They are usually found close to shore, or on coral reefs. They are easily distinguished from land snakes by their wide, flattened tail which is used for swimming, and from eels by their lack of gills. Fortunately, despite having a potent venom, when they bite they inject venom in only some 20% of cases.... sea snakes

Borassus Flabellifer

Linn.

Family: Palmae; Arecaceae.

Habitat: Coastal areas of Bengal, Bihar and Western and Eastern Peninsula.

English: Palmyra Palm, Brab tree.

Ayurvedic: Taala, Taada, Trinraj, Mahonnata, Lekhyapatra. Siddha/Tamil: Panai, Panaimaram.

Action: Fresh sap—diuretic, cooling, antiphlegmatic, laxative, anti- inflammatory. Slightly fermented juice is given in diabetes. Palm- jaggery—used as an energy food for convalscents. Ash of dry spadix—antacid, antibilious (used in heartburn). Young root, terminal buds, leaf-stalks—used in gastritis and hiccups.

The sap is given as a tonic to asthmatic and anaemic patients. Jaggery is given for anaemia, for diseases characterized by a marked loss of potassium. Palm candy is used in coughs and pulmonary affections and as a laxative for children.

The Ayurvedic Pharmacopoeia ofIn- dia recommends dried male inflorescence in dysuria.

Jaggery solution may be used in hypertension and oedema due to heart and liver diseases, also as a food for typhoid patients.

The sap is an excellent source of biologically available riboflavin.

Aqueous MeOH extract of young shoots contains heat-stable toxin; edible part of young shoot, neurotoxic to rats, but not hepatotoxic.

Dosage: Dried male inflorescence— 1-3 g (API Vol. III.)... borassus flabellifer

Botulism

A rare type of food poisoning with a mortality greater than 50 per cent, caused by the presence of the exotoxin of the anaerobic bacterium Clostridium botulinum, usually in contaminated tinned or bottled food. Symptoms develop a few hours after ingestion.

The toxin has two components, one having haemagglutinin activity and the other neurotoxic activity which produces most of the symptoms. It has a lethal dose of as little as 1 mg/kg and is highly selective for cholinergic nerves. Thus the symptoms are those of autonomic parasympathetic blockade (dry mouth, constipation, urinary retention, mydriasis, blurred vision) and progress to blockade of somatic cholinergic transmission (muscle weakness). Death results from respiratory muscle paralysis. Treatment consists of supportive measures and 4 aminopyridine and 3, 4 di-aminopyridine, which may antagonise the e?ect of the toxin.... botulism

Vinorelbine

A semi-synthetic vinca alkaloid (see VINCA ALKALOIDS) CYTOTOXIC drug recently introduced for the treatment of advanced breast cancer, when anthracycline cytotoxic antibiotics such as DOXORUBICIN have failed. Vinorelbine is also used to treat advanced non-small-cell lung cancer (see LUNGS, DISEASES OF). As with all vinca alkaloids, the drug has neurotoxic effects, usually affecting the PERIPHERAL NERVOUS SYSTEM and AUTONOMIC NERVOUS SYSTEM. It may also cause (reversible) hair loss (ALOPECIA). The drug is given intravenously.... vinorelbine

Cytotoxic

Cytotoxic means destructive to living cells. Cytotoxic drugs possess anti-cancer properties but also have the potential to damage normal tissue. Their use is twofold: to eliminate a cancer and so prolong life; or to alleviate distressing symptoms, especially in patients whose prospects of a cure are poor. In many cases CHEMOTHERAPY with cytotoxic drugs is combined with surgery, RADIOTHERAPY or both. Chemotherapy may be used initially to reduce the size of the primary TUMOUR (a process called neoadjuvant therapy) before using radiotherapy or surgery to eliminate it. Cytotoxic drugs may also be used as adjuvant treatment to prevent or destroy secondary spread of the primary tumour that has either been removed by surgery or treated with radiotherapy. All chemotherapy causes side-effects: the ONCOLOGIST – a specialist in cancer treatment – has to strike a balance between hoped-for bene?ts and acceptable (for the patient) toxic effects, which include nausea and vomiting, BONE MARROW suppression, ALOPECIA (hair loss) and teratogenic effects (see TERATOGENESIS).

Cytotoxic drugs are used either singly or in combination, when an enhanced response is the aim. Chemotherapy of cancer is a complex process and should be supervised by an oncologist in co-operation with physicians, surgeons, radiotherapists and radiologists as appropriate.

The cytotoxic drugs include:

(1) The alkylating agents which act by damaging DNA, thus interfering with cell reproduction. Cyclophosphamide, ifosfamide, chlorambucil, kelphalan, busulphan, thiotepa and mustine are examples of alkylating agents.

(2) There are a number of cytotoxic antibiotics used in the treatment of cancer – doxorubicin, bleomycin, dactinomycin, mithramycin and amsacrine are examples. They are used primarily in the treatment of acute leukaemia and lymphomas.

(3) Antimetabolites – these drugs combine irreversibly with vital enzyme systems of the cell and hence prevent normal cell division. Methotrexate, cytarabine, ?uorouracil, mercaptopurine and azathioprine are examples.

(4) Another group of cytotoxic drugs are the vinca alkaloids such as vincristine, vinblastine and vindesima.

(5) Platinum compounds such as carboplatin, cisplatin and oxaliplatin are e?ective. All of them are given intravenously, but the latter two tend to have more unpleasant side-effects. Carboplatin and cisplatin are useful in the treatment of solid tumours. Carboplatin, a derivative of cisplatin, is given intravenously in ovarian cancer and in small-cell lung cancer. Better tolerated than cisplatin, the drug causes less nausea and vomiting, nephrotoxicity, neurotoxicity and ototoxicity. Where platinum-containing therapy has failed, intravenous treatment with paclitaxel may be tried. With only a limited success rate, it is relatively toxic and should be carefully supervised; responses, however, are sometimes prolonged.

Also of increasing importance in treating cancer are interferons. These are naturally occurring proteins with complex effects on immunity and cell function. Although toxic, with numerous adverse effects, they have shown some anti-tumour e?ect against certain lymphomas and solid tumours.... cytotoxic




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