Ashwagandha is an Ayurvedic herb that is derived from extracts of the roots of Withania somnifera, a low growing evergreen shrub that is endemic to India and Southeast Asia. Sometimes called “Indian ginseng”, it is purported to have neuroprotective and antiinflammatory activities and is used to treat stress, fatigue, pain, skin diseases, diabetes, arthritis and epilepsy. It is also used as a general tonic to increase energy, reduce fatigue and counteract the effects of aging. Its efficacy in these conditions has not been consistently shown in rigorously controlled prospective studies, but it has been used in Ayurvedic medicine for centuries and is currently becoming a popular herbal product in Western countries.

Withania somnifera extracts have as many as 35 different chemical constituents and the specific active ingredient responsible for its activity has not been identified. Constituents include alkaloids, steroidal lactones, saponins, withanolides, withaferins and iron. Extracts of ashwagandha are often supplied as tablets which are taken once to three times daily. Side effects are uncommon and have not been clearly defined. Large doses can cause gastrointestinal upset, diarrhea, nausea and vomiting, probably because of direct irritation to the intestinal mucosa.

Boswellia serrata is a moderate sized deciduous tree that is native to India, the Middle East and Northern Africa. Stripping off the paper-thin bark of Boswellia trees reveals a gummy oleoresin, extracts of which have been used in Ayurvedic medicine for their antiinflammatory, antiseptic, astringent and stimulant activity to treat inflammatory conditions and gastrointestinal complaints. Boswellia extract is also used as a perfume and aroma (frankincense). Boswellia extract contains essential oils, terpenoids, sugars and volatile oils and prominently several pentacyclic triterpene acids such as beta boswellic acid. In vitro boswellic acid inhibits the synthesis of 5-lipooxygenase and decreases production of downstream pro-inflammatory mediators. Boswellia serrata extracts have been reported to be effective in alleviating symptoms of asthma, irritable bowel syndrome, inflammatory bowel disease and osteoarthritis, although the magnitude of these effects is not clear and Boswellia has not been approved for these uses in the United States.

Boswellia serrata extracts are available over-the-counter in varying concentrations, the usual recommended dose being 250 to 500 mg two or three times daily. Boswellia serrata is also found in many multiingredient products advertised for joint health and gastrointestinal complaints. Side effects are few and largely mild and transient gastrointestinal symptoms of nausea, diarrhea or constipation. In most controlled studies, adverse events were no more frequent with Boswellia extracts than with placebo.

Garcinia cambogia is an herbal product derived from fruit of the Malabar tamarind tree (also called Garcinia gummi-gutta) which is native to India, Nepal and Sri Lanka. The dried and smoked rind of the Garcinia cambogia fruit is commonly used as a food preservative and, because of its sharp, sour taste, as a flavoring agent and spice, especially in fish curries. The fruit rind has also been used in Ayurvedic medicine to treat gastrointestinal complaints and rheumatism. More recently, Garcinia cambogia has been purported to be an appetite suppressant effective in inducing weight loss.

Chemical components of Garcinia extracts include xanthones, benzophenones, amino acids and organic acids, most importantly hydroxycitric acid (HCA) the suspected ingredient responsible for its antiinflammatory and appetite suppressant activity. Garcinia fruit is 10% to 30% HCA by weight, and extracts can contain between 20% and 60% of the tricarboxylic acid. HCA inhibits ATP citrate lyase an enzyme involved in fatty acid synthesis. Garcinia derivatives and HCA have been shown to cause appetite suppression and weight loss in rats, but the effects of these organic acids and Garcinia extracts have not been consistently found in human studies. Nevertheless, Garcinia cambogia is a frequent component of over-the-counter multiingredient herbal products and has been advertised as a weight loss product. Studies in rats and other animal models have suggested that Garcinia cambogia and HCA do not have significant toxicities, although testicular toxicity was found with high doses. In humans, Garcinia has been linked to rare reports of serotonin syndrome, rhabdomyolysis and hepatic toxicity, but the role of Garcinia as opposed to other components of the herbal products or mixtures typically used in humans has not been clearly defined.

Turmeric (tur mer' ik) is a widely used herbal product derived from the roots of Curcuma longa, a perennial plant belonging to the ginger family (Zingiberaceae) that is native to India but grown throughout Southern Asia and in central America. Extracts of the rhizomes of turmeric contain volatile oils and curcuminoids (such as curcumin, demethoxycurcumin and others) which are believed to be the active antiinflammatory components of the herb and are often collectively referred to as curcumin. Curcumin comprises between 1% and 6% by dry weight of whole turmeric extracts, other components being starch, fats, proteins, fiber, vitamins, minerals, and water. The antiinflammatory effects of turmeric and curcumin are thought to be mediated by inhibition of leukotriene synthesis. Curcumin has also been reported to have antineoplastic effects, mediated perhaps by inhibition of intracellular kinases. Turmeric has been used in traditional Indian (Ayurvedic) medicine to treat many conditions including indigestion, upper respiratory infections and liver diseases. Turmeric and curcumin are under active evaluation as antiinflammatory and antineoplastic agents, for treatment of diabetes and hyperlipidemia and as therapy of liver diseases including nonalcoholic steatohepatitis (NASH). The scientific bases for the purported effects of turmeric are not well established and rigorous proof of its efficacy in any medical condition is lacking. Commercial preparations of turmeric and curcumin vary widely in curcuminoid content. The recommended daily dose varies widely (100 to >1,000 mg daily), depending on the preparation used (curcuminoids vs turmeric extract), formulation (tablets, liquid, root extract, tea) and indications. Side effects are uncommon and mild but may include dermatitis and gastrointestinal upset.

Margosa oil is an extract of the seeds of Azadirachta indica, commonly known as the neem tree native to India and Sri Lanka. In low doses, margosa oil has been a traditional remedy for centuries in India and Southeast Asia used in treating asthma, intestinal parasites, arthritis and leprosy. It is also an insecticide. The oil has a disagreeable smell and bitter taste attributable to volatile sulphur compounds and fatty acids. Free fatty acids account for 20% of its weight and bitters (nimbin, nimbinin, nimbidin and nibidol) for about 2%. The bitters are secondary products formed during storage of the oil or the seeds and concentrations can vary in different commercial samples.

Berberine is an isoquinoline alkaloid that is found in many plants and is purported to have antioxidant, antimicrobial, antiinflammatory and antineoplastic activities. It has been used in Ayurvedic as well as traditional Chinese medicine for a wide variety of conditions, including infections, diarrhea, bronchitis and digestive complaints. Berberine is found in many plants and in particularly high concentrations in Hydrastis canadensis (goldenseal), Coptis chinensis (coptis or goldenthread), Berberis aquifolium (Oregon grape), Berberis vulgaris (barberry) and Berberis aristata (tree turmeric).

Berberine has been extensively evaluated in vitro and in vivo and demonstrates antioxidant, antiproliferative, and antimicrobial activities. It has been reported to be beneficial in alleviating symptoms of arthritis, in improving glucose control and insulin resistance, in improving hyperlipidemia and lowering blood pressure. Nevertheless, berberine has not been approved for any of these uses in the United States.

Berberine is widely available over-the-counter in varying concentrations alone and combined with other herbs and nutritional substances in many multiingredient dietary supplements. The usual recommended dose of the herbal product is 250 to 500 mg two or three times daily. Side effects are few and largely mild and transient gastrointestinal symptoms of nausea, abdominal bloating, diarrhea or constipation. In most controlled studies, adverse events were no more frequent with berberine than with placebo and serious adverse events have been rare.

Tribulus is prepared from the leaves and roots of the low-growing shrub and common weed Tribulus terrestris that is found in dry habitats in many parts of the world, including Asia, Africa, Australia and North and South America. Extracts of the shrub have been used in traditional medicine as an aphrodisiac, general tonic and mood stimulant for centuries. A major use of tribulus has been for sexual dysfunction such as erectile dysfunction in men and hypoactive sexual syndromes in women, but also for menopausal symptoms, premenstrual syndrome and infertility.

Recently tribulus has been used commonly for increasing athletic performance. Tribulus is also purported to be beneficial for several other medical conditions, including urinary tract infections, kidney stones, hypertension, angina pectoris, hypercholesterolemia, gastrointestinal disorders, diarrhea and even liver disease. Studies in animal models suggested that tribulus increases testosterone levels in males and estrogen levels in females, but these hormonal effects have not been reproduced consistently in humans. Furthermore, in controlled trials, improvements in sexual function were no greater with Tribulus terrestris extracts than with placebo. The active ingredients in extracts of tribulus are believed to be saponins such as dioscine, diosgenin and protodioscin which are steroidal molecules and thought to increase levels of sex hormones.

Tribulus is available in tablets and capsules of 250 and 500 mg, and the usual daily dose is 250 to 750 mg daily. Tribulus terrestris is also included in many multi-ingredient dietary supplements used for sexual dysfunction and body building. Tribulus is reported to be well tolerated but may be associated with mild gastrointestinal discomfort, nausea or dyspepsia. The plant, also known as puncture vine because of the sharp spines on its fruit, has been linked to outbreaks of liver injury in grazing animals known as geeldikkop or hepatogenous photosensitivity. The toxic component of the plant is believed to be the steroidal sapogenins which form crystals in bile ducts and renal tubules in sheep that feed upon its leaves.