Hindawi Publishing Corporation Evidence-Based Complementary and Alternative Medicine Volume 2016, Article ID 5202908, 9 pages http://dx.doi.org/10.1155/2016/5202908 Review Article Health-Promoting Properties of Eucommia ulmoides:AReview Tarique Hussain,1,2 Bi’e Tan,1,3 Gang Liu,2 Oso Abimbola Oladele,4 Najma Rahu,5 M. C. Tossou,1,2 and Yulong Yin1 1 Observation and Experiment Station of Animal Nutrition and Feed Science in South-Central China, Ministry of Agriculture, Hunan Provincial Engineering Research Center for Healthy Livestock and Poultry Production, Key Laboratory of Agro-Ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan 410125, China 2University of the Chinese Academy of Sciences, Beijing 10008, China 3Hunan Collaborative Innovation Center for Utilization of Botanical Functional Ingredients, Changsha, Hunan 410000, China 4Department of Animal Nutrition, College of Animal Science and Livestock Production, Federal University of Agriculture, Abeokuta 110101, Nigeria 5Department of Veterinary Microbiology, Faculty of Animal Husbandry and Veterinary Sciences, Sindh Agriculture University, Tando Jam, Sindh 70050, Pakistan Correspondence should be addressed to Bi’e Tan; [email protected] Received 4 November 2015; Accepted 31 January 2016 Academic Editor: Il-Moo Chang Copyright © 2016 Tarique Hussain et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Eucommia ulmoides (EU) (also known as “Du Zhong” in Chinese language) is a plant containing various kinds of chemical constituents such as lignans, iridoids, phenolics, steroids, flavonoids, and other compounds. These constituents of EU possess various medicinal properties and have been used in Chinese Traditional Medicine (TCM) as a folk drink and functional food for several thousand years. EU has several pharmacological properties such as antioxidant, anti-inflammatory, antiallergic, antimicrobial, anticancer, antiaging, cardioprotective, and neuroprotective properties. Hence, it has been widely used solely or in combination with other compounds to treat cardiovascular and cerebrovascular diseases, sexual dysfunction, cancer, metabolic syndrome, and neurological diseases. This review paper summarizes the various active ingredients contained in EU and their health- promoting properties, thus serving as a reference material for the application of EU. 1. Introduction the leaf of EU was reported to reduce fattiness and enhance energy metabolism. Flavonoid compounds (such as rutin, Eucommia ulmoides (EU) (commonly called “Du Zhong” in chlorogenic acid, ferulic acid, and caffeic acid) have been Chinese language) belong to the family of Eucommiaceae, reported to exhibit antioxidants activity in the leaves of EU a genus of the small tree native to Central China [1]. [6]. This plant is widely cultivated in China on a large scale Although there has been enough literature on phyto- because of its medicinal importance. About 112 compounds chemical properties of EU, few studies however existed on have been isolated from EU which include lignans, iridoids, the pharmacological properties of the various compounds phenolics, steroids, and other compounds. Complementary extracted from the barks, seeds, stems, and leaves of EU. This herbs formula of this plant (such as delicious tea) has review paper will elucidate detailed information regarding shown some medicinal properties. The leaf of EU has higher different compounds extracted from the various parts (barks, activity related to cortex, flower, and fruit [2, 3]. The leaves seeds, stem, and leaf) of EU and the prospective uses of these of EU have been reported to enhance bones strength and compounds in health-promoting properties with scientific body muscles [4], thus leading to longevity and promoting lines of evidence and thus provide a reference material for the fertility in humans [5]. Delicious tea formula made from application of EU. 2 Evidence-Based Complementary and Alternative Medicine 2. Chemical Composition of exhibit protective effects on kidneys as observed by malon- Eucommia ulmoides aldehyde and glutathione levels after renal perfusions [21]. Histological examination also showed evidence of antiox- Various compounds isolated from different parts of EU are idative properties. Extracts from the bark of EU using 70% shown in Table 1. ethanol also showed protective effects against cadmium at 125–500 mg/kg [22]. Histological examination also showed 2.1. Lignans and Iridoids. Lignans and their derivatives that EU in combination with Panax pseudoginseng at 25% are the key components of EU [7]. To date, 28 lignans and 50% weight, respectively, for six weeks at a dose rate of (such as bisepoxylignans, monoepoxylignans, neolignans, 35.7–41.6 mg/kg exerted light protective effects on glomerular andsesquilignans)havebeenisolatedfrombark,leaves, filtration rate [8]. Two new polysaccharides have been sepa- and seeds of EU. Iridoid glycoside, a class of secondary rated from EU, which are eucomman A and B [23]. metabolites, is the second main component of EU. Iridoids are typically found in plants known as glycosides. Twenty- 2.5. Other Ingredients and Chemicals. Amino acids, microele- four iridoids have been isolated and identified from EU ments, vitamins, and fatty acids have also been isolated (Table 1). These isolated compounds include geniposidic from EU [17, 21–23]. Sun et al. also discovered new com- acid, aucubin, and asperuloside which have been reported pounds such as n-octacosanoic acid, and tetracosanoic-2,3- to have wide pharmacological properties [8–10]. Two new dihydroxypropylester from EU [24]. compounds of iridoids, Eucommides-A and -C, have recently Fatty acid composition of oil extracted from the seed of been isolated. These two natural compounds are considered EU showed different concentrations of polyunsaturated fatty as conjugates of iridoid and amino acids. However, the acids such as linoleic acid, linolenic acid (56.51% of total mechanism underlying their activity is not available [11]. fatty acids, TFAs), and linolelaidic acid (12.66% of TFAs). Meanwhile, the main monounsaturated fatty acid isolated 2.2. Phenolic Compounds. Phenolic compounds which are from the seed was found to be isoleic acid (15.80% of TFAs). derivedfromthefoodshavebeenreportedtohavepositive Dominant saturated fatty acids isolated include palmitic acid impactonhumanhealth[12,13].About29phenoliccom- and stearic acid which represent 9.82% and 2.59% of TFAs, pounds have been isolated and identified from EU [14]. Total respectively [25]. content of phenolic compounds (in gallic acid equivalents of all the extracts) was analyzed using the Folin-Ciocalteu 3. Health-Promoting Compounds of phenol reagent. Effects of seasonal variation on the contents Eucommia ulmoides of some compounds and antioxidants have been reported. Within the same year, higher contents of phenolics and 3.1. Protective Effects on Cardiovascular System. In Chinese flavonoidswerediscoveredintheleavesofEUinAugust traditional medicines, Eucommia is considered as a major and May, respectively. Rutin, quercetin, geniposidic acid, and herbal tonic for cardiac patients. Eucommia bark extract is an aucubin existed in higher concentration in May or June [15]. active component used for antihypertensive formulations. It Moreover,higheractivityof1,1-diphenyl-2-picrylhydrazyl has been confirmed in many human as well as animal models (DPPH) radical scavenging activity and metal ion chelating as a vasorelaxant. Lignan from EU when administered to rats ability were found in the leaves of EU harvested in August. of the Okamoto strain (SHR) at the dose rate of 300 mg/kg Increased content of food antioxidants was also reported in for 16 weeks resulted in improved vascular remodeling and May when compared to other periods of the year [15]. The reduced mean arterial blood pressure. EU minimizes blood leaf of EU has been found to be a rich source of aminoacids, pressure at the dose of 500–1000 mg/kg. However, in high vitamins, minerals, and flavonoids such as quercetin, rutin, fructose fed diet, it develops insulin resistance and hyper- and geniposidic acid [11, 16]. A total of 7 flavonoids have been tension [26–28]. Supplementation of 500 and 1000 mg of EU isolated from Eucommia plants [17]. Rutin and quercetin are for 8 weeks and thrice daily for 2 weeks showed minimal the most important flavonoids [18]. Flavonoids are important reduction in blood pressure and reduction in systolic and compounds which are common in nature and are considered diastolic blood pressure [29]. Antihypertensive effect on the as secondary metabolites and function as chemical messen- parasympathetic nervous system has been reported following gers, physiological regulators, and cell cycle inhibitors. the application of EU [30]. EU also serves as a vasorelaxative agent depending on nitric oxide and assumed to be linked 2.3. Steroids and Terpenoids. Six steroids and five terpenoids with potassium channels [31]. EU has beta blocking potential have been extracted and categorized from EU. These which at 0.5% w/v reduces isoproterenol-stimulated lipolysis include -sitosterol, daucosterol, ulmoprenol, betalin, from 2.67 to 1.4 times the buffer control [29]. EU has been betulic acid, ursolic acid, eucommidiol, rehmaglutin C, and demonstrated to prevent hypertensive remodeling which is 1,4,5,7-tetrahydro-7-hydroxymethyl-cyclopenta[c]pyran-