Dietary Supplements: An Overview

Transcription

1 Chapter 1 Dietary Supplements: An Overview Downloaded via on April 11, 2019 at 05:02:51 (UTC). See for options on how to legitimately share published articles. Chi-Tang Ho 1, James E. Simon 2, Fereidoon Shahidi 3, and Yu Shao 4 1 Department of Food Science, Rutgers, The State University of New Jersey, 65 Dudley Road, New Brunswick, NJ New Use Agriculture and Natural Plant Products Program, Department of Plant Biology and Plant Pathology, Rutgers, The State University of New Jersey, 59 Dudley Road, New Brunswick, NJ Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada 4 GlaxoSmithKline Consumer Healthcare, 1500 Littleton Road, Parsippany, NJ The use of dietary supplements in North America and particularly in the United States is widespread. The chemistry and biological studies related to the ingredients involved, particularly botanical bioactives are rapidly progressing. An overview of some aspects of dietary supplements described in detail in the book is provided. Introduction A dietary supplement is defined under the Dietary Supplement Health and Education Act (DSHEA) of 1994 and regulated by Food and Drug Administration, in A dietary supplement can be a product intended to supplement the diet that bears or contains one of more of the dietary ingredients including vitamins, minerals, amino acids, herbs and other botanical extracts (/). The sale of products in the dietary supplement market has approached $20 billion in the United States (7) American Chemical Society

2 3 Top Dietary Supplements The use of dietary supplements in the United States is widespread and this continues to grow as more people become concerned about the access and quality of health care, and seek complementary and alternative medicines (2). Major dietary supplements sold in the United States are still vitamins and minerals such as vitamin B-complex, multiple vitamin-minerals, vitamin A and vitamin C, calcium and iron. Other popular dietary supplements are Co-QlO for energy and performance, glucosamine and chondroitin for managing osteoarthritis, soy and soy products for lowing cholesterol, among others. Botanical Dietary Supplements With the increasing demand for prevention of diseases, herbal products have become popular in the international market, not to mention in those countries with a long history of using herbal medicines such as China, India and Japan. Currently there are about 750,000 plant species, 300,000 registered species, 30,000-75,000 medicinal plants, 20,000 medicinal plants listed by World Health Organization (WHO) and 400 medicinal plants widely traded in the world. In the U.S., herbal products are mainly regulated as dietary supplements and sold in different forms such as fresh plant products, dried botanical powders, liquid botanical extracts, soft extracts, dry extracts, tinctures and purified natural compounds. The global open market, allows all kinds of botanical products to be sold in the U.S. with ginseng, ginkgo, saw palmetto, echinacea, soy, bilberry, grape seed and green tea extracts as top-selling items. Table I lists some of the popular botanical dietary supplements along with their potential active components and functions (J). Several of the botanical dietary supplements listed in Table I such as black cohosh (Chapter 5) and kava (Chapter 17) are discussed in this book. Phytochemistry of other botanicals such as Gnetum species (Chapter 4), Aframomun melegueta (Chapter 6), Xylopia aethiopia (Chapter 7) and basil (Chapter 8) are also reviewed. Bioactives from Marine Sources Chapter 3 discusses in details the bioactives from marine sources. Marine species provide a rich source of food as well as by-products that could be used for production of a wide range of bioactive compounds. These bioactives include omega-3 fatty acids, proteins and biopeptides, carotenoids and carotenoproteins, enzymes, chitinous materials and glucosamine as well as

3 4 Table I. Popular Botanical Dietary Supplements, Their Potential Active Components and Functions Dietary Potential active Major potential health Latin name Supplements components benefit Astragalus Astragalus Polysaccharides, Immunomodulatory, membranaceus saponins hepatoprotective astragalosides) Black cohosh Cimicifuga Fukinolic acid Relief of menopausal racemosa 23-epi-26- symptoms deoxyactein Cranberry Vaccinium Proanthocyanidins Prevention and macrocarpon treatment of urinary tract infections Dang Gui Angelica Ligustilide Treatment of sinensis gynecological conditions Echinacea Echinacea Polysaccharides Treatment of common purpurea, and glycoproteins, cold, cough, and upper E. pallida, cichoric acid, respiratory infections E. angustifolia alkamides Feverfew Tanacetum Parthenolide and Alleviation of fever, parthenium other sesquiterpene headache, and lactones women's ailments Garlic Allium sativum Allyl sulfur Antibacterial, compounds anticarcinogenic, antithrombotic, hypolipidemic Ginger Zingiber Gingerols Antiemetic, officinale anti-inflammatory, Roscoe digestive aid Ginkgo Ginkgo biloba Ginkgolids, Treatment of cerebral biloba flavonoids dysfunction and circulatory disorders American Panax Ginsenosides Therapeutic effects on ginseng quinquefolium immune function, cardiovascular diseases, cancer, sexual function Asian Panax ginseng Ginsenosides Combat ginseng psychophysical tiredness and asthenia

4 5 Table I. Continued Dietary Supplements Goldenseal Grape seed extract Green tea polyphenols Kava Licorice Maca Milk thistle Pycnogenol Red clover Reishi mushroom Saw Palmetto Soy isoflavones Latin name Hydrastis Canadensis Vitis vinfera Camellia sinensis Piper methysticum Glycyrrhiza glabra Lepidium meyenii Silybum marianum Pinus pinaster ssp. atlantica Trifolium pretense Ganoderma lucidum Triterpene saponins, flavonoids and other phenolics Aromatic isothiocyanates Silymarin Procyanidins Isoflavones Triterpenoids, polysaccharides Serenoa repens Unknown Glycine max Potential active Major potential health components benefit Alakaloid berberine Soothing irritated skin and P-hydrastine and mucous membranes, easing dyspepsia Proanthocyanidins Antioxidant, antiinflammatory, immunostimulatory, antiviral and anticancer Epigallocatechin Preventive effects on gal late and heart diseases, cancer, catechins neurodegenerative disorders and diabetes Kava lactones Effects on relaxing and mood calming Possess soothing, antiinflammatory and antitussive properties Genistein, daidzein Use for aphrodisiac purpose Treatment of liver disorders Use for protection of the circulation, and to store capillary healing Treatment for menopausal symptoms Antitumor and immunomodulating effects Use for prostate health Prevention of menopausal symptoms, osteoporosis, coronary heart disease and cancer Continued on next page.

5 6 Table 1. Continued Dietary Potential active Major potential health Latin name Supplements components benefit St. John's wort Hypericum Hyperforin, Treatment of mild perforatum hypercin depression Valerian Valeriana Valepotriates Use for mild sedative officinalis L. (iridoids) and sleep disturbance Yohimbe Pausinystalia Yohimbine Use for aphrodisiac johimbe purpose carotenoproteins, enzymes, chitinous materials and glucosamine as well as calcium, among others. The bioactives present in marine resources are effective in rendering beneficial health effects and reducing the risk of a number of chronic diseases. Thus, marine bioactives may serve as important value-added nutraceuticals, natural health products and functional food ingredients that can be used for health promotion and disease risk reduction. Fruits and Their By-products as Dietary Supplements Epidemiological studies indicate that the frequently and high intake of fresh fruits and vegetables is associated with lower incidence of some types of cancer and other age-related diseases. Table II lists some bioactive phytochemicals in selected fruits. Citrus is one of the most widely available and popular types of fruits, phytochemicals such as limonene, flavonoids and limonoids are recently gaining recognition for their impressive chemopreventive properties (4). Chapters 13 to 16 in this book review extensively the chemistry, biological activities and bioavailability of polymethoxyflavones (PMFs) in citrus peels. PMFs found almost exclusively in Citrus genus, particularly in the peels of sweet orange (Citrus sinensis (L.) Osbeck) and mandarin (Citrus reticulate Blanco). They have been of particular interest due to their broad spectrum of biological activities, including anti-inflammatory anti-carcinogenic, and antiatherogenic properties (Chapter 13), Chronic inflammation was closely associated with the increased risk of various human cancers (5). Quality Control of Dietary Supplements For different commercial purposes, there are different quality control and quality assurance standards for botanical dietary supplements. However, usually they follow some general rules, the botanicals must be authenticated, safe to use,

6 7 Table II. Bioactive Phytochemicals in Selected Fruits Fruits Citrus Apple Grape Cranberry Noni Pomegranate Bioactive Phytochemicals limonene, limonoids, flavonoids, polymethoxyflavones quercetin-3-galactoside, quercetin-3-glucoside, epicatechin, phloridzin proanthocyanidins, quercetin, ellagic acid proanthocyanidins, anthocyanins, catechins, triterpenes ursolic acid, rutin, scopoletin, saccharide fatty acid esters ellagic acid, ellagitannins, cyanidin with a limit of foreign materials, heavy metals, aflatoxins and pesticides. The ph value, ash contents, moisture contents and particle size should be in a reasonable range. Also microbiological tests for ingredients of interest must be passed. Usually, herbal dietary supplements can be comparatively screened for quality related to their active ingredient content by instrumental methods (colorimetric, HPLC, LC/MS). The HPLC and LC/MS are suitable methods for quality control including the chemical fingerprinting of plant powders, tinctures and extracts. The inclusion of such instrumental methods of analysis, in addition to the typical review of published literature, should be a standard and critical component in the assessment of quality in botanical standardization for all plantbased dietary supplements. Too often, the literature is used in place of, rather than as a compliment to, actual analytical testing. Companies and even research groups may lack specific (or accurate) standards needed for compound identification and quality assessment in specific botanicals due to their lack of availability and/or expense and instead rely on previously reports which may illustrate elution of compounds pictured in labeled peaks from GC and/or LC analysis; thus false positive compound identifications may result. Many botanicals are "quality challenged" in that: (i) natural products may vary significantly from their own stated label claim (if there is one); (ii) another plant part or plant species is used either on purpose or inadvertently; (iii) adulteration is more common than acknowledged; and (iv) some botanical products can be spiked with synthetic chemicals or compounds from other botanicals (6). To overcome these problems now facing the botanical industry, we recommend that reference materials and reference standards for these botanicals should be available through governmental and research institutes or non-profit organizations. Universal analytical methods should continue to enlarge for development and validation of most popular botanicals, and in particular for those botanicals that are potentially problematic from a safety perspective. Detailed genetic and chemical fingerprinting for every popular herb is needed and software programs to integrate the various chemical and genetic fingerprinting systems are long overdue. Using instrumental analysis as a core and standard part of the quality control process in botanicals, though well recognized, needs further implementation and continued focus (7).

7 8 References 1. Coates, P.M.; Blackman, MR.; Cragg, G.M.; Levine, M.; Moss, J.; White, J.D. Encyclopedia of Dietary Supplements, Marcel Dekker, New York, NY, Marriott, B.M. In Dietary Supplements of Plant Origin: A Nutrition and Health Approach, Maffei, M. ed. Taylor & Francis, London, UK, 2003; pp Hathcock, J. J. Nutr. 2001,131,1114S-1117S. 4. Patil, B.S.; Brodbelt, J.S.; Miller, E.G.; Turner, N.D. In Potential Health Benefits of Citrus, Patil, B.S.; Turner, N.D.; Miller, E.G.; Brodbelt, J.S. eds. ACS Symp. Ser. 936, American Chemical Society, Washington, DC, 2006, pp Huang, M.-T.; Ghai, G.; Ho, C.-T. Comprehensive Rev, Food Sci. Food Safety 2004, 3, Wang, M.; Wu, Q.L.; Simon, J.E.; Ho, C.-T. In Asian Functional Foods, Shi, J.; Shahidi, F.; Ho, C.-T. eds. Marcel Dekker, Inc., New York, NY, 2005; pp Wang, M.; Wu, Q.L.; Simon, J.E.; Liang, C.P.; Ho, C.-T. In Herbs: Challenges in Chemistry and Biology, Wang, M.; Sang, S.; Hwang, L.S.; Ho, C.-T. eds. ACS Symp. Ser. 925, American Chemical Society, Washington, DC, 2006, pp