J Nutr Health JNH Journal of Nutrition and Health 2288-3886 2288-3959 The Korean Nutrition Society 10.4163/jnh.2013.46.5.401 Research Article Study on antioxidative, antidiabetic and antiobesity activity of solvent fractions of smilax china L. leaf extract Kang Yun Hwan 1 Lee Young-Sil 3 Kim Kyoung Kon 2 Kim Dae Jung 1 Kim Tae Woo 1 Choe Myeon 1 2 Well-being Bioproducts RIC, Kangwon National University, Gangwon 200-701, Korea. Department of Bio-Health Technology, Kangwon National University, Gangwon 200-701, Korea. Center for Nutraceutical and Pharmaceutical Materials, Myongji University, Yongin 449-728, Korea. To whom correspondence should be addressed. (mchoe@kangwon.ac.kr) 10 2013 31 10 2013 46 5 401 409 06 09 2013 06 10 2013 17 10 2013 © 2013 The Korean Nutrition Society 2013 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Smilax china L., a native plant found in Asian countries, has several medicinal properties including antioxidant, anti-inflammatory, and anti-cancer effects. Although the root of the plant is commonly used as traditional herbal medicine in Korea and China, the medicinal properties of the leaves have not gained the same attention. In this study, we analyzed the antioxidant activity, α-glucosidase inhibitory effect and lipid accumulation inhibition effect of Smilax china L. leaf water extract (SCLE) and its solvent fractions. SCLE was fractionated by using a series of organic solvents, including ethylacetate (EA) and n-butanol (BuOH). The EA fraction had the highest total polyphenol content (440.20 ± 12.67 mg GAE/g) and total flavonoid content (215.14 ± 24.83 mg QE/g). The radical scavenging activity IC50 values of the EA fraction for 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) were 0.022 mg/mL and 0.13 mg/mL, respectively. Further, SOD-like activity and reducing power values of the EA fraction were higher than those of the other fractions. However, both the α-glucosidase and lipid accumulation inhibition assays showed that the BuOH fraction (83.35 ± 4.18% at 1 mg/mL) and water extract (11.27 ± 2.67%) were more effective than the EA fraction (64.13 ± 6.35%, and 45.66 ± 7.20%). These results provide new insights into the potential anti-diabetic and anti-obesity effects of Smilax china L. leaf.

 Smilax china L anti-diabetic activity anti-obesity activity antioxidant organic solvent fraction Well-being Bioproducts Regional innovation Center B0009702

This work was supported by grants of Well-being Bioproducts Regional innovation Center project (B0009702)

 King H Aubert RE Herman WH Global burden of diabetes, 1995-2025: prevalence, numerical estimates, and projections Diabetes Care 1998 21 9 1414 1431 Kim SG Choi DS Epidemiology and current status of diabetes in Korea Hanyang Med Rev 2009 29 2 122 129 Choi YY Sohn HS Shin HT Clinical benefits of self-monitoring of blood glucose in non-insulin treated patients with type 2 diabetes: a systematic review and meta-analysis Korean J Clin Pharm 2010 20 3 183 192 Toeller M Diet therapy of diabetes mellitus Fortschr Med 1991 109 2 41 42 45 Koivisto VA Insulin therapy in type II diabetes Diabetes Care 1993 16 Suppl 3 29 39 Boulé NG Haddad E Kenny GP Wells GA Sigal RJ Effects of exercise on glycemic control and body mass in type 2 diabetes mellitus: a meta-analysis of controlled clinical trials JAMA 2001 286 10 1218 1227 Derosa G Maffioli P α-Glucosidase inhibitors and their use in clinical practice Arch Med Sci 2012 8 5 899 906 Standl E Schnell O Alpha-glucosidase inhibitors 2012 - cardiovascular considerations and trial evaluation Diab Vasc Dis Res 2012 9 3 163 169 Heo SJ Hwang JY Choi JI Han JS Kim HJ Jeon YJ Diphlorethohydroxycarmalol isolated from Ishige okamurae, a brown algae, a potent alpha-glucosidase and alpha-amylase inhibitor, alleviates postprandial hyperglycemia in diabetic mice Eur J Pharmacol 2009 615 1-3 252 256 Evans JL Goldfine ID Maddux BA Grodsky GM Oxidative stress and stress-activated signaling pathways: a unifying hypothesis of type 2 diabetes Endocr Rev 2002 23 5 599 622 Seghrouchni I Drai J Bannier E Rivière J Calmard P Garcia I Orgiazzi J Revol A Oxidative stress parameters in type I, type II and insulin-treated type 2 diabetes mellitus; insulin treatment efficiency Clin Chim Acta 2002 321 1-2 89 96 Kim BH Son SM Mechanism of developing diabetic vascular complication by oxidative stress J Korean Endocr Soc 2006 21 6 448 459 Mehran AE Templeman NM Brigidi GS Lim GE Chu KY Hu X Botezelli JD Asadi A Hoffman BG Kieffer TJ Bamji SX Clee SM Johnson JD Hyperinsulinemia drives diet-induced obesity independently of brain insulin production Cell Metab 2012 16 6 723 737 Song HS Park YH Jung SH Kim DP Jung YH Lee MK Moon KY Antioxidant activity of extracts from Smilax china root J Korean Soc Food Sci Nutr 2006 35 9 1133 1138 Cha BC Lee EH Antioxidant activities of flavonoids from the leaves of Smilax china Linne Korean J Pharmacogn 2007 38 1 31 36 Choi SS Cha BY Iida K Lee YS Yonezawa T Teruya T Nagai K Woo JT Artepillin C, as a PPARγ ligand, enhances adipocyte differentiation and glucose uptake in 3T3-L1 cells Biochem Pharmacol 2011 81 7 925 933 Yadav D Chaudhary AA Garg V Anwar MF Rahman MM Jamil SS Khan HA Asif M In vitro toxicity and antidiabetic activity of a newly developed polyherbal formulation (MAC-ST/001) in streptozotocin-induced diabetic Wistar rats Protoplasma 2013 250 3 741 749 Kim JM Baek JM Kim HS Choe M Antioxidative and antiasthma effect of Morus bark water extracts J Korean Soc Food Sci Nutr 2010 39 9 1263 1269 Moreno MI Isla MI Sampietro AR Vattuone MA Comparison of the free radical-scavenging activity of propolis from several regions of Argentina J Ethnopharmacol 2000 71 1-2 109 114 Kim KH Kim NY Kim SH Han IA Yook HS Study on antioxidant effects of fractional extracts from Ligularia stenocephala leaves J Korean Soc Food Sci Nutr 2012 41 9 1220 1225 Re R Pellegrini N Proteggente A Pannala A Yang M Rice-Evans C Antioxidant activity applying an improved ABTS radical cation decolorization assay Free Radic Biol Med 1999 26 9-10 1231 1237 Jeong KY Kim ML Physiological activities of Ulmus pumila L. extracts Korean J Food Preserv 2012 19 1 104 109 Hue SM Boyce AN Somasundram C Antioxidant activity, phenolic and flavonoid contents in the leaves of different varieties of sweet potato (Ipomoea batatas) Aust J Crop Sci 2012 6 3 375 380 Ryu HW Lee BW Curtis-Long MJ Jung S Ryu YB Lee WS Park KH Polyphenols from Broussonetia papyrifera displaying potent alpha-glucosidase inhibition J Agric Food Chem 2010 58 1 202 208 Jeong HJ Lee SG Lee EJ Park WD Kim JB Kim HJ Antioxidant activity and anti-hyperglycemic activity of medicinal herbal extracts according to extraction methods Korean J Food Sci Technol 2010 42 5 571 577 Lee JM Park JH Chu WM Yoon YM Park E Park HR Antioxidant activity and alpha-glucosidase inhibitory activity of stings of Gleditsia sinensis extracts J Life Sci 2011 21 1 62 67 Kim MA Son HU Yoon EK Choi YH Lee SH Comparison of anti-diabetic activities by extracts of grape cultivar Korean J Food Preserv 2012 19 3 400 405 Lee HJ Park KY Body weight, cardiovascular risk factors, and self-efficacy of diabetic control among obese type II diabetic patients J Korean Acad Nurs 2005 35 5 787 797 de Ferranti S Mozaffarian D The perfect storm: obesity, adipocyte dysfunction, and metabolic consequences Clin Chem 2008 54 6 945 955

Extraction and fractionation of Smilax china L. leaf extracts(SCLE) by using various solvents

Total polyphenol content (A) and total flavonoid content (B) of SCLE fractions. Garlic acid and quercetin were used as standard compounds for the measurement of polyphenol and flavonoid contents respectively. Results are presented as Mean ± SD of three independent experiments. **: p < 0.001 as compared to the SCLE.

SOD-like activity of SCLE fractions. SOD-like activity assay was performed by using a range of SCLE concentrations. Ascorbic acid was used as positive control. Results are presented as Mean ± SD of three independent experiments. *: p < 0.05 as compared to the SCLE.

Anti-diabetic activity of SCLE fractions. α-Glucosidase inhibitory activity assay was performed using a range of concentrations (incubation time, 30 min)(A) and time-points (concentration, 0.25 mg/mL)(B). Acarbose was used as positive control. Results are presented as Mean ± SD of three independent experiments. *: p < 0.05, **: p < 0.001 as compared to the SCLE. #p < 0.001 as compared to the acarbose.

Effects of SCLE fractions on lipid accumulation. 3T3-L1 adipocytes were stained with Oil-Red O for 1 hr. Stained oil droplets were dissolved in isopropanol and quantified by spectrophotometric analysis at 500 nm. Results are expressed as Mean ± SD of three independent experiments and each sample was measured in triplicate. **: p < 0.001 as compared to the control.

IC50 value1) of SCLE fractions for DPPH and ABTS

1) IC50 value is the concentration of sample required for 50% inhibition 2) Values with different superscripts are significant increase at the same column (p < 0.05)

Each value is expressed as mean ± SD in triplicate experiments

Reducing power of SCLE fractions

1) Positive control 2) Values with different superscripts are significant increase at the same row (p < 0.05).

Each value is expressed as Mean ± SD in triplicate experiments