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In vitro α-Amylase and α-Glucosidase Inhibitory Activity of Dioscorin from Dioscorea alata

Anocha Sansud, Diana Jose, Sudathip Sae-tan, Kittipong Rattanaporn


Dioscorea alata is a species of yam found in many countries in Southeast Asia. It contains many bioactive compounds consisting of steroidal saponins, phenolic compounds flavonoids, polysaccharides, and proteins. Eighty to eighty-five of the soluble proteins in the tuber of D. alata are dioscorin. Dioscorin (31 kDa) is the major storage protein of yam tuber, exhibiting biochemical and immunomodulatory properties, such as antioxidant activity, reducing blood pressure and angiotensin I converting enzyme (ACE) inhibitors activity. The aims of this research focused on extraction of the total soluble protein from D. alata tuber, purification of dioscorin, and study of in vitro inhibitory activity of α-amylase and α-glucosidase of dioscorin extracts. The results showed that a maximum yield of total soluble protein was obtained from the buffers extraction using Tris-HCl buffer at pH 9.0 resulting in the protein concentration of 15.10 mg/g with a protein extraction yield of 31.56 ± 2.36%. The crude protein was further recovered using ammonium sulfate precipitation and dialysis. SDS-PAGE analysis showed that dioscorin from crude extracts was precipitated at the concentration of ammonium sulfate of 60% saturation. The purified dioscorin was obtained from anion exchange chromatography (DEAE-Sephacel) and its molecular weight of 31 kDa was estimated on SDS-PAGE. Furthermore, the α-amylase inhibitory activities of crude extract (1 mg/mL), purified dioscorin obtain from gastric digestion and purified dioscorin obtained from intestinal digestion were at 14.44% 2.21% and 78.13%, respectively. Moreover, the results showed that the α-glucosidase inhibitory activity of the crude extract, and purified dioscorin obtained from gastric digestion were at 10.56% and 2.61%, respectively.


[1] WHO, “Global action plan for the prevention and control of NCDs 2013–2020,” 2013. [Online]. Available: item/9789241506236


[2] WHO, “Global strategy on diet, physical activity and health,” 2004. [Online]. Available: https://


[3] WHO, “World Report on Diabetes,” 2016. [Online]. Available: publications/i/item/9789241565257


[4] P. J. Harvey and D. Boulter, “Isolation and characterization of the storage protein of yam tubers (Dioscorea rotundata),” Phytochemistry, vol. 22, pp. 1687–693, 1983.


[5] W. C. Hou, J. S. Liu, H. J. Chen, T. E. Chen, C. F. Chang, and Y. H. Lin, “Dioscorin, the major tuber storage protein of yam (Dioscorea batatas decne) with carbonic anhydrase and trypsin inhibitor activities,” Journal of Agricultural and Food Chemistry, vol. 47, pp. 2168−2172, 1999.


[6] FAO, Tropical Root and Tuber Crops: Production, Perspectives and Future Prospects. Rome, Italy: Food & Agriculture, 2013.


[7] J. P. Wanasundera and G. Ravindran, “Nutritional assessment of yam (Dioscorea alata) tubers,” Plant Foods for Human Nutrition, vol. 46, no. 1, pp. 33–39, 1994.


[8] S. Edison, M. Unnikrishnan, B. Vimala, S. V. Pillai, M. N. Sheela, M. T. Sreekumari, and K. Abraham, Biodiversity of Tropical Tuber Crops in India. TamilNadu, India: National Biodiversity Authority, 2006.


[9] FAO, “Statistical Database,” 2020. [Online]. Available:


[10] Y. A. Liu, “Antioxidative ability, dioscorin stability, and the quality of yam chips from various yam species as affected by processing methods,” Journal of Food Science, vol. 74, pp. 118–125, 2009.


[11] M. Hanefeld, M. Cagatay, T. Petrowitsch, D. Neuser, and D. Petzinna, “Acarbose reduces the risk for myocardial infarction in type 2 diabetic patients: Meta-analysis of seven long-term studies,” European Heart Journal, vol. 25, no. 1, pp. 10–16, 2004.


[12] R. S. Conlan, L. A. Griffiths, J. A. Napier, P. R. Shewry, S. Mantell, and C. Ainsworth, “Isolation and characterisation of cDNA clones representing the genes encoding the major tuber storage protein (dioscorin) of yam (Dioscorea cayenensis Lam.),” Plant Molecular Biology, vol. 28, pp. 369–380, 1995.


[13] Y. J. Jheng, W. Y. Tsai, K. H. Chen, K. W. Lin, C. L. Chyan, C. C. Yang, and K.C. Lin, “Recombinant dioscorins of the yam storage protein expressed in Escherichia coli exhibit antioxidant and immunomodulatory activities,” Protein Expression and Purification, vol. 85, pp. 77–85, 2012.


[14] D. M. Yang, Y. C. Chang, Y. J. Chen, B. S. Wang, and K. H. Lin, “Dioscorin, the major tuber storage protein of yam (Dioscorea batatas Decne) with carbonic anhydrase and trypsin inhibitor activities,” Journal of Agricultural and Food Chemistry, vol. 54, no. 7, pp. 2794–2802, 2006.


[15] B. Alberts, A. Johnson, J. Lewis, M. Raff, K. Roberts, and P. Walter, “Molecular biology of the cell,” Annals of Botany, vol. 91, pp. 401–405, 2002.


[16] Z. P. Wang, X. M. Xue, Q. Gong, C. Xie, W. Fan, J. L. Yang, and Y. Li, “Stress-induced dissociation between a chloroplastic dehydroascorbate reductase and photosynthesis in Arabidopsis thaliana,” Plant, Cell & Environment, vol. 33, no. 5, pp. 751–767, 2010.


[17] J. J. Holst and F. Gribble, “Role of incretins in the regulation of insulin secretion in diabetes,” Journal of Clinical Investigation, vol. 129, no.10, pp. 4030–4040, 2019.


[18] C. N. Huang, K. C. Chan, W. T. Lin, H. T. Wu, and Y. J. Chen, “Antihypertensive effects of wild yam (Dioscorea alata L.) extracts in rats fed a high-fat diet,” Journal of Food and Drug Analysis, vol. 21, no. 4, pp. 361–368, 2013.


[19] K. H. Lin, Y. L. Yang, D. M. Yang, Y. L. Huang, C. N. Huang, M. C. Yin, and Y. J. Chen, “Antioxidant activity of dioscorin from Dioscorea spp. against oxidative stress-induced cell damage in vitro,” Journal of Agricultural and Food Chemistry, vol. 58, no. 19, pp. 10876– 10881, 2010.


[20] S. Makiyah, N. Nuruldjati, and M. Sasmito, “Lymphocyte proliferation on the hypersensitivity of balb/c mice after given ethanol extract tuber of of Dioscorea alata,” KnE Life Sciences, vol. 2, pp. 107–111, 2015.


[21] Z. Lin, B. Bai, X. Liu, Y. Wang, M. Li, and D. Zhao, “α-Glucosidase inhibitors from Chinese yam (Dioscorea opposita Thunb.),” Food Chem, vol. 126, pp. 203–206, 2011.


[22] R. R. Holman, R. L. Coleman, J. C. Chan, J. L. Chiasson, H. Feng, and A. Taubes, “Effects of acarbose on cardiovascular and diabetes outcomes in patients with coronary heart disease and impaired glucose tolerance (ACE),” Lancet Diabetes Endocrinol, vol. 2 no. 10, pp. 769–776, 2010.


[23] M. Minekus, M. Alminger, P. Alvito, and P. Balance, “A standardised static in vitro digestion method suitable for food - an international consensus,” Food & Function Journal, vol. 5, pp. 1113–1124, 2014.


[24] T. P. Ellappan, K. Balasubramaian, K. Chidambaram, and C. M. Subhash, “Α-glucosidase and α-amylase inhibitory activity of Senna surattensis,” Journal of Acupuncture and Meridian Studies, vol. 6, pp. 24–30, 2013.


[25] M. A. Telagari, “In-vitro α-amylase and α-glucosidase inhibitory activity of Adiantum caudatum linn. and Celosia argentea linn. extracts and fractions,” Indian Journal of Pharmacology, vol. 47, pp. 425–429, 2015.


[26] W. C. Hou, M. H. Lee, H. J. Chen, W. L. Liang, C. H. Han, Y. W. Liu, and Y. H. Lin, “Antioxidant activities of dioscorin, the storage protein of yam (Dioscorea batatas decne) tuber,” Journal of Agricultural and Food Chemistry, vol. 49, pp. 4956–4960, 2001.


[27] B. Yong, Y. Jiang, W. Fan, and Y. Zhang, “Effect study of different methods to extract protein from sweet potato tuberous roots,” Chinese Journal of Applied and Environmental Biology, vol. 20, no. 2, pp. 211–216, 2014.


[28] H. Y. Xue, Y. Zhao, Z. H. Liu, X. W. Wang, J. W. Zhang, X. Peng, and Y. L. Xue, “Recovery of yam soluble protein from yam starch processing wastewater,” Scientific Reports, vol. 10, 2020, Art. no. 5384.


[29] F. L. Hsu, Y. H. Lin, M. H. Lee, C. L. Lin, and W.C. Hou, “Both dioscorin, the tuber storage protein of yam (Dioscorea alata cv. Tainong no. 1), and its peptic hydrolysates exhibited angiotensin converting enzyme inhibitory activities,” Journal of Agricultural and Food Chemistry, vol. 50, pp. 6109–6113, 2002,


[30] S. Sharma, R. Gupta, and R. Deswal, “Dioscorea alata tuber proteome analysis shows over thirty dioscorin isoforms and novel tuber proteins,” Plant Physiology and Biochemistry, vol. 114, pp. 128–137, 2017.


[31] Y. T. Chen, W. T. Kao, and K.W. Lin, “Effects of pH on the total phenolic compound, antioxidative ability and the stability of dioscorin of various yam cultivars,” Food Chemistry, vol. 107, pp. 250– 257, 2008.


[32] S. L. Shih, Y. S. Lin, S. Y. Lin, and W. C. Hou, “Effects of yam dioscorin interventions on improvements of the metabolic syndrome in high-fat diet-induced obese rats,” Botanical Studies, vol. 56, p. 4, 2015.


[33] X. X. Guo, H. S. Xiao, J. Liu, B. C. Sheng, Y. Wang, and P. J. Bao, “Chinese purple yam (Dioscorea alata L.) extracts inhibit diabetes-related enzymes and protect HepG2 cells against oxidative stress and insulin resistance induced by FFA,” Food Science and Technology Research, vol. 21, no. 5, pp. 677–683, 2015.


[34] B. C. Adedayo, A. O. Ademiluyi, G. Oboh, and A. A. Akindahunsi, “Interaction of aqueous extracts of two varieties of yam tubers (Dioscorea spp.) on some key enzymes linked to type 2 Diabetes in vitro,” International Journal of Food Science & Technology, vol. 47, pp. 703–709, 2012.


[35] P. Mccue, Y. I Kwon, and K. Shetty, “Anti-amylase, antiglucosidase and anti-angiotensin I-converting enzyme potential of selected foods,” Journal of Food Biochemistry, vol. 29, pp. 278– 294, 2005.

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DOI: 10.14416/j.asep.2023.10.002


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