ReviewStudy on the pharmacological activities and chemicalstructures of Viburnum dilatatumZhiheng Gao, Yufei Xi, Man Wang, Xiaoxiao Huang*, Shaojiang Song*Key Laboratory of Computational Chemistry-Based Natural Antitumor Drug Research &Development, Liaoning Province, School of Traditional Chinese Materia Medica, ShenyangPharmaceutical University, Shenyang 110016, ChinaAbstractViburnum dilatatum (jiami in Chinese), belonging to the Caprifollaceae family, is widely distributed in Japan and China. Phytochemical investigations of Viburnum dilatatum (V. dilatatum) have resulted in the isolation of triterpenoids, phenolic glycosides essential oil, norisoprenoids, etc. Research results have shown that the chemical constituents of V. dilatatum possess various pharmacological activities, including antihyperglycemic, antioxidant activity and antiulcer effects. This study reviewed the chemical constituents and pharmacological activities of V. dilatatum to provide practical and useful information for further research and development of this plant.Keywords: Viburnum dilatatum; pharmacological activity; chemical structures1 IntroductionViburnum dilatatum (called jiami in Chinese, gamazumi in Japanese and snowball tree in English), beloinging to family Caprifoliaceae, is a deciduous low tree distributed widely in the hills of northern China and Japan [1]. There are many types of chemical constituents in Viburnum dilatatum (V. dilatatum), including triterpenoids, * Author to whom correspondence should be addressed. Address:School of Traditional Chinese Materia Medica, Shenyang Pharmaceutical University, 103 Wenhua Rd., Shenyang 110016, China; Tel.: +86-24-43520793 (Xiaoxiao Huang); +86-24-43520707 (ShaojiangSong);E-mail:*******************(XiaoxiaoHuang); ****************(ShaojiangSong).Received: 2021-04-16 Accepted: 2022-08-28phenolic glycosides and norisoprenoids [2-4]. The leaves have been utilized as a traditional Chinese medicine, and phenolic compounds have been reported as the main active chemical component of the leaves. Many researchers have analyzed the functions of these medicinal components and found that these components have good antioxidant antihyperglycemic and antiulcer effects. For example, the gamazumi crude extract obtained from the squeezed juice of the fruit prevented oxidative injury in rats [5]. This review described the chemical structures and pharmacological activities of V. dilatatum, so as to help readers understand comprehensively the research progress of V. dilatatum and provide help for the development of V. dilatatum.2 Chemical constituents and structuresPrevious reports have indicated that the main chemical constituents of V. dilatatum are phenolic glycosides and triterpenoids.2.1 Phenolic glycosidesThirteen phenolic glycosides were isolated and identified from V. dilatatum by extensive spectroscopic methods, namely p -hydroxyphenyl-6-O -trans-caffeoyl-β-D -glucoside (1) [6], p -hydroxyphenyl-6-O -trans-caffeoyl-β-D -alloside (2) [6], 4-allyl-2-methoxyphenyl-6-O -β-D -apiosyl(1→6)-β-D -glucoside (3) [6], 1-(4’-hydroxy-3’-methoxypheny1)-2-[2’’-hydroxy-4’’-(3’’’-hydroxypropyl)]-1,3-propanediol-l-O -β-D -glucopyranoside (erythro isomer) (4-7) [7], neochlorogenic acid methyl ester (8-9) [7], cryptochlorogenic acid methyl ester (10-11) [7], cyanidin-3-sambubioside (Cy-3-sam) (12) [8], cyanidin-3-glucoside (Cy-3-glc) (13) [8], 5-O -caffeoyl-4-methoxyl quinic acid (4-MeO-5-CQA) (14) [8], chlorogenic acid (5-CQA) (15) [8], quercetin (16) [8], 2-(glucopyranosyloxy)-benzyl-3-(glucopyranosyloxy)-benzoate (17) [9] and jiamizioside E (18) [10]. These structures are shown in Fig. 1.Fig. 1 Phenolic glycosides isolated from V . dilatatumContinued fig. 12.2 TriterpenoidsThere were about seventeen triterpenoids isolated and characterized from V. dilatatum , such as viburnols A (19) [11], viburnols B (20) [11], viburnols C (21) [11], viburnols D (22) [11], viburnols E (23) [11], viburnols F (24) [12], viburnols G (25) [12], viburnols H (26) [12], viburnols I (27) [12], viburnols J (28) [12],viburnols K (29) [12], viburnudienone B 2methyl ester (30) [13], viburnenone H 2 (31) [13],v i b u r n e n o n e B 2 m e t h y l e s t e r (32) [13], viburnudienone B 1 methyl ester (33) [13], viburnenone H 1 (34) [13], and viburnenone B 2 methyl ester (35) [13]. The structures are shown in Fig. 2.Continued fig. 23 Pharmacological activities3.1 Antioxidant activityOxidative stress caused by free radicals and their derivatives leads to disturbances in redox homeostasis. Reactive oxygen species (ROS) are not only endogenously produced during intracellular metabolic processes but also generated by exogenous stimuli such as UV radiation, pollutants, smoke and drugs. The cell triggers its defense systems or undergoes apoptosis when intracellular oxidative status increases. It influences numerous cellular processes including core signaling pathways, which are associated with development of systematic and chronic disorders, such as aging and cancer. Therefore, it is critical to remove cellular oxidants and restore redox balance.solution of V. dilatatum (GSS) had strong antioxidant activity in vivo and prevent stress-induced oxidative damage by the XYZ-dish method and the澳electron spin resonance (ESR) method [14]. The experimental result showed that the concentrations of lipid peroxide in plasma, liver and stomach in the GSS group were reduced. Furthermore, the activities of plasma lactic dehydrogenase, amylase and creatine phosphokinase are ordinarily increased by stress. However, these activities in the GSS group decreased to that in the control group. It was concluded that gastric ulcer formation, increase of lipid peroxidation in plasma and tissues and elevation of plasma enzymatic activities were confirmed in rats with water immersion restraint stress. It was also found that intake of GSS could protect the stomach and other tissues from oxidative damage.Kim et al. identified and isolated two major anthocyanins by NMR and LC-ESI-MS/MS, namely, cyanidin 3-sambubioside (I) and kuromanin (II) [15]. By the electron spin resonance method, the superoxide anion radical scavenging activities of I and II were evaluated with the IC 50 values of 17.3 and 69.6 µM, and their activities on hydroxyl radicals were evaluated with the IC 50 values of 4.3 and 53.2 mM. As the positive control, the IC 50 values of ascorbic acid were 74.2 µM on superoxide anion radicals and 3.0 mM on hydroxyl radicals, respectively. The above results suggested that these anthocyanins with radical scavenging properties might be the key compounds contributing to the antioxidant activity and physiological effects of V . dilatatum fruits.Woo et al. determined the free radical scavenging capacity of VD (the leaves of V. dilatatum ) [16]. Anti-oxidant activity of the extracts was assessed by the ability to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) or 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals. Butylated hydroxytoluene (BHT), a synthetic antioxidant, or α-tocopherol, was used as the positive control in these assays. The experimental result showed that VD inducedincrease in radical scavenging activity. In addition, lipid peroxidation inhibitory activity was determined via measurement of MDA (Malondialdehyde) levels using mouse liver tissue homogenate treated with various concentrations of the extracts. The concentration-dependent decrease in MDA levels observed was consistent with radical scavenging activities of the extracts. To examine whether VD extracts could protect mam-malian cells from oxidative stress, cultures of a human mammary gland-derived epithelial cell line MCF-7 were treated with each extract prior to challenging them with tBHP. The intracellular ROS (Reactive oxygen species) production was determined with the relative intensity of dichlorofluorescein fluorescence. While intracellular ROS formation was significantly promoted by tBHP treatment, the augmented ROS level was significantly reduced after the treatment with VD extracts.3.2 Antihyperglycemic effectIwai et al. used an oral glucose tolerance test on the diabetic rats [17]. They found that the elevation of plasma glucose level after oral administration of 2 g/kg glucose was suppressed by the repeated administration of the freeze-dried powder of V. dilatatum fruit juice (CEV). The α-glucosidase inhibitory activities of isolated compounds from CEV were also measured. Cyanidin 3-sambubioside and 5-caffeoyl quinic acid A showed inhibitory activity. These results suggested that V. dilatatum fruit had the antihyperglycemic effects.4 ConclusionV. dilatatum is distributed widely in the hills of northern China and Japan. Currently, the studies on V. dilatatum have been conducted at home and abroad, but few studies focus on its chemical components and pharmacological activities. Previousphytochemical investigations showed that the constituents of V. dilatatum included triterpenoids, phenolic glycosides, norisoprenoids and other compounds. This study describes thirteen phenolic glycosides and seventeen triterpenoids and their different degrees of antihyperglycemic, antioxidant activity and antiulcer effects, aiming to provide a reference for further studies on V. dilatatum and pharmaceutical development.References[1] Jeffrey B, Harborne A. Colour atlas of medicinal plantsof Japan. Phytochemistry, 1981, 20: 1467.[2] Miyazawa M, Hashidume S, Takahashi T, et al. Aromaevaluation of gamazumi (Viburnum dilatatum) by aroma extract dilution analysis and odour activity value.Phytochem Anal, 2012, 23: 208-213.[3] Kurihara T, Kikuchi M. Studies on the constituentsof flowers. IV. On the components of the flower of Viburnum dilatatum Thunb. J Health Sci, 1975, 95: 1098-1102.[4] Machida K, Kikuchi M. Norisoprenoids from Viburnumdilatatum. Phytochemistry, 1996, 41: 1333-1336. [5] Iwai K, Onodera A, Matsue H. Mechanism of preventiveaction of Viburnum dilatatum Thunb (gamazumi) crude extract on oxidative damage in rats subjected to stress. J Sci Food Agric, 2010, 83: 1593-1599.[6] Machida K, Nakano Y, Kikuchi M. Phenolic glycosidesfrom Viburnum dilatatum. Phytochemistry, 1991, 30: 2013-2014.[7] Machida K, Kikuchi M. Phenolic compounds fromViburnum dilatatum. Phytochemistry, 1992, 31: 3654-3656.[8] Kim MY, Iwai K, Matsue H. Phenolic compositions ofViburnum dilatatum Thunb. fruits and their antiradical properties. J Food Compos Anal, 2005, 18: 789-802. [9] Lu D, Yao S. Phenolic glycoside from the roots ofViburnum dilatatum. Nat Prod Commun, 2009, 4: 945-946.[10] Wu B, Zeng X, Zhang Y. New metabolite fromViburnum dilatatum. Nat Prod Commun, 2010, 5: 1097-1098.[11] Machida K, Kikuchi M. Viburnols: Novel triterpenoidswith a rearranged dammarane skeleton from Viburnum dilatatum. Tetrahedron Lett, 1996, 37: 4157-4160. [12] Machida K, Kikuchi M. Viburnols: Six noveltriterpenoids from Viburnum dilatatum. Tetrahedron Lett, 1997, 38: 571-574.[13] Machida K, Kikuchi M. Studies on the Constituents ofViburnum Species. XIX. Six New Triterpenoids from Viburnum dilatatum Thunb. Chem Pharm Bull, 1999, 47: 692-694.[14] Iwai K, Onodera A, Matsue H, et al. Antioxidant activityand inhibitory effect of Gamazumi (Viburnum dilatatum THUNB.) on oxidative damage induced by water immersion restraint stress in rats. Int J. Food Sci Nutr, 2001, 52: 443-451.[15] Kim MY, Iwai K, Onodera A, et al. Identification andAntiradical Properties of Anthocyanins in Fruits of Viburnum dilatatum Thunb. J Agric Food Chem, 2003, 51: 6173-6177.[16] Woo YJ, Lee HJ, Jeong YS, et al. Antioxidant Potentialof Selected Korean Edible Plant Extracts. Bio Med Res Int, 2017, 2017: 1-9.[17] Iwai K, Kim MY, Akio O, et al. Alpha-glucosidaseinhibitory and antihyperglycemic effects of polyphenols in the fruit of Viburnum dilatatum Thunb. J Agric Food Chem, 2006, 54: 4588-4592.。
