Nutrition: Diet Therapy and Nutritional Supplements
Paloma Tejero, Hernán Pinto in Aesthetic Treatments for the Oncology Patient, 2020
Omega-3 fatty acids are a good source of lignans, compounds that may have a mild estrogenic effect. When a weak substance similar to estrogen takes the place of the body's natural strong estrogen in a breast cell's estrogen receptor, the weak substance may act as a relative antiestrogen. By acting this way, lignans may help fight the type of breast cancer that depends on estrogen to grow. However, research conducted so far to determine whether omega-3 fatty acids influence breast cancer risk has not been conclusive. A study in rats showed that a diet enriched with DHA induced a reduction in breast tumors, with a 60% increase in plasma levels of the tumor-suppressing protein BRCA1. It was observed that in animals receiving diets enriched with omega-3 fatty acids, there was an increase in the efficacy of the drugs doxorubicin and mitomycin C65, which are used to inhibit tumor growth. In addition, an increase in the inhibitory effect of the drug tamoxifen was observed in estrogen-dependent models, which would allow the potential use of omega-3 as an adjuvant to standard chemotherapy to be considered.
An Alternative Approach for Anti-Alzheimer’s Compounds from Plant Extracts
Atanu Bhattacharjee, Akula Ramakrishna, Magisetty Obulesu in Phytomedicine and Alzheimer’s Disease, 2020
The lignans are bioactive plant compounds, non-nutritional, non-caloric phenolic plant compounds that are found at the highest concentration in sesame and flax seeds and in lower concentrations in grains, other seeds, vegetables, and fruits (Abef and Yamauchi, 1990; Gokare and Akula, 2010). The chemistry and biosynthesis of lignans in plants present in major food sources and their metabolism in humans have been studied (Zhao et al., 2003). The plant lignans most commonly distributed in foods are lariciresinol, matairesinol, pinoresinol, and secoisolariciresinol (Houghton and Howes, 2005). Some lignans are present in foods, including medioresinol (sesame seeds, rye, and lemons), sesamin, syringaresinol (grains), and their precursor sesamolin (Rao et al., 2011). Lignans are recognized as a class of natural products with a particularly wide spectrum of important biological activities, with the main biological properties of lignans being antitumor and antiviral activities (Zhao et al., 2003; Kim et al., 2015) (Figure 2.2 and Table 2.2).
Formulated Natural Selective Estrogen Receptor Modulators: A Key To Restoring Women’s Health
Megh R. Goyal, Durgesh Nandini Chauhan in Plant- and Marine-Based Phytochemicals for Human Health, 2018
Lignans are estrogen-like chemicals and also act as antioxidants. They are compounds that form the building blocks of plant cell walls and phytoestrogens assist the regulation of body’s estrogen production. When estrogen levels are too high, the lignans attach to the ERs, reducing the activity of body’s natural estrogen hormones and blocking their effect in certain tissues. Research has shown that lignan phytoestrogens prevent some forms of cancer17, 23, 73 by blocking estrogenic activity. The term lignan is used for a diverse class of phenylpropanoid dimers and oligomers. Secoisolariciresinol (SECO) and matairesinol-5 are two lignan dimers that are not estrogenic by themselves, but are readily converted to the mammalian lignans, enterodiol, and enterolactone, respectively, which are estrogenic.31, 80 The conversion occurs by gut microflora and the mammalian lignans are readily absorbed. The content of phytolignans is measurable in various body fluids such as urine, feces, and plasma.
Evaluation of the inhibition of human carboxylesterases (CESs) by the active ingredients from Schisandra chinensis
Published in Xenobiotica, 2019
Qiang Fu, Kai Yang, Rui-Xia Hu, Zuo Du, Cui-Min Hu, Xibo Zhang
Schisandra chinensis, also called wuweizi in Chinese, is the fruit of Schisandra chinensis (Turcz.) Baill., and has been officially utilized as a Chinese medicine for more than two thousand years. Schisandra chinensis has been utilized as a sedative and tonic to treat various diseases such as chronic cough and dyspnea, nocturnal emission, spermatorrhea, enuresis, and frequent urination. Schisandra chinensis can also be used as flavoring agent of foods (Alexander & Wikman, 2008; Chen et al., 2013). It can be used for the treatment of viral and chemical liver injuries with an obvious therapeutic effect (Ali et al., 2018). Schisandra chinensis can also be used to treat cancer and some inflammation diseases (Zhao et al., 2013). Through isolation from Schisandra chinensis, many bioactive ingredients (e.g., lignans, nortriterpenes, sesquiterpenes, phenolic acids, etc.) have been obtained. Among these ingredients, lignans have been widely accepted to be one of the most important pharmacological ingredients. For example, Schisandrol B has been demonstrated to play an important role in the protection of liver toxicity (Jiang et al., 2016; Zeng et al., 2017). Another lignan Schisandrin A has been reported to exert anti-tumor activity toward multiple types of cancers, such as ovarian cancer (Lee et al., 2018). Schisandrin B has been also demonstrated to show therapeutic function towards cancers, such as glioma (Jiang et al., 2017).
Effect of Dietary Flaxseed Intake on Circulating Sex Hormone Levels among Postmenopausal Women: A Randomized Controlled Intervention Trial
Published in Nutrition and Cancer, 2019
Vicky C. Chang, Michelle Cotterchio, Beatrice A. Boucher, David J. A. Jenkins, Lucia Mirea, Susan E. McCann, Lilian U. Thompson
Lignans are a major class of phytoestrogens, estrogen-like compounds with cancer-preventive properties (1). While lignans are generally found at low concentrations in a wide range of plant foods, flaxseed is by far the richest dietary source, containing predominantly secoisolariciresinol diglucoside (SDG) (2). Once ingested, SDG is metabolized by intestinal bacteria to the biologically active mammalian lignans (enterolignans), enterodiol and enterolactone (3,4), whose circulating and urinary levels are strongly correlated with dietary lignan intake (5–8). Enterolignans are structurally similar to endogenous sex hormones and have been shown to exert weak hormonal effects and inhibit carcinogenesis in animal models (9,10). As such, lignans, as well as flaxseed, have been investigated for their possible role in the prevention of hormone-related cancers (4,9,11), particularly breast cancer (12–17).
Flaxseed Lignans Enhance the Cytotoxicity of Chemotherapeutic Agents against Breast Cancer Cell Lines MDA-MB-231 and SKBR3
Published in Nutrition and Cancer, 2018
Yunyun Di, Franklyn De Silva, Edward S. Krol, Jane Alcorn
Lignans are natural compounds possessing a unique diphenolic structure and exist in minor quantities in many foods but have appreciable levels in flaxseed (13). Dietary consumption of the flaxseed lignan, secoisolariciresinol diglucoside (SDG), results in glucosidic cleavage in the gastrointestinal tract to yield secoisolariciresinol (SECO), which is further converted to the mammalian lignans, enterodiol (ED) and enterolactone (ENL), by the intestinal microflora (14). The literature suggests ENL is the major bioactive lignan (15), but the SDG metabolites are extensively metabolized by enterocytic and hepatic UDG-glucuronosyltransferase enzymes during their absorption process yielding high systemic levels of glucuronide conjugates of these lignan metabolites and low levels of ENL, ED, and SECO (16,17). Nonetheless, several studies report improved survival of patients with postmenopausal breast cancers with high circulating total ENL levels (i.e., ENL plus ENL glucuronide (ENL-Gluc) (18–21). ENL, and to a more limited extent, SECO, are known to possess antiproliferative properties (22,23). In vitro studies suggest multiple mechanisms are potentially involved in the inhibition of breast cancer cell growth (24,25). As well, animal experiments demonstrate that dietary supplementation with flaxseed lignans enhances the inhibitory effect of tamoxifen through upregulation of estrogen receptor- and growth factor-signaling pathways (26,27). Such data indicates the potential application of flaxseed lignans as adjuvant therapy against breast cancer.
Related Knowledge Centers
- Antifeedant
- Flax
- Lignin
- Phytoestrogen
- Polyphenol
- Rye
- Enterolignan
- Sesame
- Secoisolariciresinol Diglucoside
- Wheat