Nettle (Urtica dioica)

Nettle: Medical Uses Nettle is used for allergy symptoms and anemia. It also is used to prevent hair loss, stimulate hair growth, promote weight loss, and strengthen the liver. Historical Uses Nettle is the Anglo-Saxon word for “needle.” In folklore, nettle was used as a footbath for rheumatism, a spring tonic, a diuretic, and a remedy for asthma. Growth Nettle grows 2 to 3 feet high and has dark green leaves with stinging hairs. Touching or brushing against the leaves sometimes causes a severe local irritation. Parts Used • Leaves • Roots Major Chemical Compounds • FlavonoidsAcetylcholine • Histamine • Serotonin • Chlorophyll • Carotenoids • High amounts of iron, calcium, vitamin C, and silica. Nettle: Clinical Uses Nettle is used for allergy symptoms and anemia. It also is used to prevent hair loss, stimulate hair growth, promote weight loss, and strengthen the liver. It is used as a nutritive tea for pregnant and breast-feeding women. It can also be used for arthritis pain and for its anti-HIV effects. Mechanism of Action This herb has antihistamine and diuretic effects. It increases production of breast milk. It has antiprostatic, androgenic, keratogenetic, Read more […]

Herb-Drug Interactions: Cannabis

Cannabis sativa L. (Cannabaceae) Synonym(s) and related species Bhang, Dagga, Ganja, Hashish, Indian hemp, Marihuana, Marijuana. Cannabis indica Lam. Constituents Cannabis herb contains a wide range of cannabinoids, which are the major active compounds. The main psychoactive constituent is delta9-tetrahydrocannabinol (THC; dronabinol), and it is the cause of many of the pharmacological effects elicited by the consumption of cannabis. However, other cannabinoids, which do not possess psychoactive properties, such as cannabidiol, cannabinol (a decomposition product of delta9-tetrahydrocannabinol), cannabigerol and cannabichromene, are increasingly being investigated for their pharmacological and therapeutic properties. Cannabinoids are often found in the plant as their acid metabolites, e.g. ll-nor-9-carboxy-delta9-tetrahydrocannabinol, cannabidiol acid and others, especially if the plant has been grown in a cooler climate. These decarboxylate to the parent cannabinoid at high temperatures, such as during smoking. Most medicinal cannabis products have been heat treated to ensure that the cannabinoids are present only in the non-acid form. Use and indications Cannabis has no current established use in herbal Read more […]

Herb-Drug Interactions: Coffee

Coffea L. species. (Rubiaceae) Synonym(s) and related species Arabian coffee is from Coffea arabica. Robusta coffee is from Coffea canephora (Pierre ex Froehner) also known as Coffea robusta (Linden ex De Wild.). Other species include Coffea liberica. Constituents The kernel of the dried coffee bean contains xanthine derivatives, the main one being caffeine (1 to 2%), with some theobromine and theophylline. It also contains polyphenolic acids such as chlorogenic acids and various diterpenes (e.g. kahweol, cafestrol). Use and indications Coffee has been used as a stimulant and diuretic. However, when roasted, coffee beans are most commonly used as a beverage. Pharmacokinetics The pharmacokinetics of caffeine are discussed under caffeine. Evidence suggests that chlorogenic acid is hydrolysed in the gastrointestinal tract to free caffeic acid, which is then conjugated to form the glucuronate or sulphate. Interactions overview Coffee contains significant amounts of caffeine, so the interactions of caffeine, are relevant to coffee, unless the product is specified as decaffeinated. By virtue of its caffeine content, coffee may also cause serious adverse effects if used with other drugs or herbs with similar Read more […]


CYCLOOXYGENASE INHIBITORS bind reversibly or irreversibly to the enzyme cyclooxygenase (originally referred to as the prostaglandin synthase system or ‘prostaglandin H2 synthase'; (PGHS)-l and (PGHS)-2). Members of the prostaglandin family have a number of proinflammatory or hyperalgesic actions, and consequently many cyclooxygenase inhibitors are used as anthnflammatories and ANALGESICS. Prostanoids are members of the eicosanoid family of phospholipid mediators, and are comprised of the thromboxanes and the prostaglandins, both of which are formed by the complex cyclooxygenase system. They share common precursors in the form of a series of unstable cyclic endoperoxides. The first stage of the transformation of arachidonic acid has the enzyme endoperoxide synthase oxygenate arachidonate, followed by cyclization to give a cyclic endoperoxide called PGG2. These reactions are inhibited by cyclooxygenase inhibitors. Subsequently, PGG2 is converted by a peroxidase action to PGH2. This is a common precursor for a number of different pathways, forming prostacyclin (by prostacyclin synthase), the various prostaglandins or thromboxanes (by thromboxane synthase). See THROMBOXANE SYNTHASE INHIBITORS. The conversion depends Read more […]

Herb-Drug Interactions: Tea

Camellia sinensis (L.) Kuntze (Theaceae) Synonym(s) and related species Camellia thea Link, Thea sinensis L. Note that Green tea (predominantly produced in China and Japan) is produced from steam-treated tea leaves. Black tea or Red tea (predominantly produced in India, Sri Lanka and Kenya) is processed by fermentation and heating, whereas Oolong tea is partially fermented. Pharmacopoeias Powdered Decaffeinated Green Tea Extract (The United States Ph 32). Constituents Tea contains caffeine (around 1 to 5%), with minor amounts of other xanthines such as theophylline and theobromine. Tea also contains flavonoids, the content of which varies between green (unfermented) and black (fermented) tea. Green tea appears to contain greater quantities of the flavonol-type flavonoids than black tea. Black tea also contains theaflavins, which are produced during the fermentation process. Other flavonols present include quercetin and kaempferol. Oolong tea contains some unique flavones known as oolonghomobisflavins. Tea also contains up to 24% tannins. Use and indications The leaf buds and very young leaves of tea are used as a stimulant and diuretic, actions that can be attributed to the caffeine content. They are Read more […]

Herb-Drug Interactions: Resveratrol

Types, sources and related compounds Resveratrol is a polyphenol present in most grape and wine products and is the compound largely credited with providing the health benefits of red wine. However, the concentration is very variable between foods and supplements, so it is difficult to evaluate the clinical relevance of the available information. Use and indications Resveratrol is used for its reputed anti-ageing effects. It is said to have antioxidant properties and antiplatelet effects, and is therefore promoted as having benefits in a variety of cardiovascular diseases, including atherosclerosis. It also has some oestrogenic and anti-inflammatory activity, and is under investigation in the prevention and treatment of cancer, because it appears to reduce cell proliferation. Pharmacokinetics An in vitro study reported that resveratrol inhibited the cytochrome P450 isoenzyme CYP3A4, but was much less potent than erythromycin, a known, clinically relevant, moderate CYP3A4 inhibitor. Similar results were found in other studies. Interestingly, red wine also inhibited CYP3A4, but this effect did not correlate with the resveratrol content. In other studies resveratrol had only very weak inhibitory effects on CYP1A2, Read more […]

Herb-Drug Interactions: Pepper

Piper nigrum L. (Piperaceae) Synonym(s) and related species Black and white pepper are derived from the fruits of the same species, Piper nigrum L. Black pepper is the unripe fruit which has been immersed in hot water and dried in the sun, during which the outer pericarp shrinks and darkens into a thin, wrinkled black layer. White pepper consists of the seed only, prepared by soaking the fully ripe berries, removing the pericarp and drying the naked seed. Long pepper, Piper longum L., is a closely related species where the fruits are smaller and occur embedded in flower ‘spikes’, which form the seed heads. Constituents Alkaloids and alkylamides, the most important being piperine, with piperanine, piperettine, piperlongumine, pipernonaline, lignans and minor constituents such as the piperoleins, have been isolated from the fruits of both species of pepper. Black pepper and long pepper also contain a volatile oil which may differ in constitution, but is composed of bisabolene, sabinene and many others; white pepper contains very little. The pungent taste of pepper is principally due to piperine, which acts at the vanilloid receptor. Use and indications Pepper is one of the most popular spices in the world, Read more […]

Herb-Drug Interactions: Goldenseal

Hydrastis canadensis L. (Ranunculaceae) Synonym(s) and related species Hidrastis, Hydrastis, Orange root, Yellow root. Xanthorhiza simplicissima Marsh. Pharmacopoeias Goldenseal (US Ph 32); Goldenseal Rhizome (European Ph 2008); Goldenseal Root (British Ph 2009); Powdered Goldenseal (US Ph 32); Powdered Goldenseal Extract (The United States Ph 32). Constituents The rhizome of goldenseal contains the isoquinoline alkaloids hydrastine and berberine, to which it may be standardised, and also berberastine, hydrastinine, canadine (tetrahydroberberine), canalidine and others. Use and indications Used for inflammatory and infective conditions, such as amoebic dysentery and diarrhoea; gastric and liver disease. The alkaloids are antibacterial, amoebicidal and fungicidal. For details on the uses of berberine, a major constituent of goldenseal, see berberine. Pharmacokinetics In several in vitro studies, goldenseal root has been identified as a potent inhibitor of the cytochrome P450 isoenzyme CYP3A4, but more modest inhibitory effects were seen clinically with the CYP3A4 probe substrate, midazolam. Two studies in healthy subjects, found that goldenseal, given for 14 to 28 days, reduced the metabolism or urinary Read more […]

Herb-Drug Interactions: Ginkgo

Ginkgo biloba L. (Ginkgoaceae) Synonym(s) and related species Fossil tree, Kew tree, Maidenhair tree. Salisburia adiantifolia Sm., Salisburia biloba Hoffmanns. Pharmacopoeias Ginkgo (US Ph 32); Ginkgo capsules (US Ph 32); Ginkgo dry extract, refined and quantified (British Ph 2009, European Ph 2008); Ginkgo leaf (British Ph 2009, European Ph, 6th ed., 2008 and Supplements 6.1, 6.2, 6.3 and 6.4); Ginkgo tablets (US Ph 32); Powdered ginkgo extract (The United States Ph 32). Constituents Ginkgo leaves contain numerous flavonoids including the biflavone glycosides such as ginkgetin, isoginkgetin, bilobetin, sciadopitysin, and also some quercetin and kaempferol derivatives. Terpene lactones are the other major component, and these include ginkgolides A, B and C, and bilobalide, Ginkgo extracts may be standardised to contain between 22 and 27% flavonoids (flavone glycosides) and between 5 and 12% terpene lactones, both on the dried basis. The leaves contain only minor amounts of ginkgolic acids, and some pharmacopoeias specify a limit for these. The seeds contain ginkgotoxin (4-O-methylpyridoxine) and ginkgolic acids. Use and indications The leaves of ginkgo are the part usually used. Ginkgo is often used Read more […]

Herb-Drug Interactions: Ginger

Zingiber offidnale Roscoe (Zingiberaceae) Synonym(s) and related species Gan Jiang, Zingiber. Not to be confused with the wild gingers, which are Asarum canadense L. and Asarum europaeum L. Pharmacopoeias Ginger (British Ph 2009, European Ph 2008, US Ph 32); Ginger Capsules (US Ph 32); Ginger Tincture (US Ph 32); Powdered Ginger (The United States Ph 32). Constituents The constituents of ginger vary depending on whether fresh or dried forms are used. Generally, ginger rhizomes contain volatile oils of which zingiberene and bisabolene are major components: zingerone, zingiberol, zingiberenol, curcumene, camphene and linalool are minor components. The rhizomes also contain gingerols and their derivatives, gingerdiols, gingerdiones and dihydrogingerdiones. Sho-gaols are formed from gingerols during drying, and together these make up the pungent principles of ginger. Ginger extracts have been standardised to contain a minimum of 15mL/kg of essential oil with reference to the dried drug. Use and indications Ginger is thought to possess carminative, anti-emetic, anti-inflammatory, antispasmodic and antiplatelet properties. Both fresh and dried ginger are mainly used to settle the stomach, to alleviate Read more […]