Inhibitory Effect of Soybean Seed Extracts on Human Salivary Amylase: An in vitro Study


  • Tumkur University, Department of Studies and Research in Biochemistry, Tumkur, Karnataka, 572 103, India
  • IBDP, Indus International School, Department of Chemistry, Bangalore, Karnataka, India
  • Tumkur University, Department of Studies and Research in Biotechnology, Tumkur, Karnataka, 572 103, India


Enzymes are biological catalysts that accelerate the rate of metabolic reactions. Amylases are the class of hydrolase, split the (1-4) glycosidic bonds of polysaccharides into glucose or maltose. Salivary and pancreatic α-amylases share 92 % of analogy in their catalytic region. In diabetic condition, α-amylases become a major challenge in managing postprandial hyperglycemia. Natural inhibitors have been well-known to treat diabetes and were accounted to contain compounds with anti α-amylase activity. Soybean has been reported to have anti-diabetic activity because of its rich phytochemical content. The aim of the present study is to examine the in vitro inhibitory effects of aqueous, methanol and acid methanol extracts on the salivary amylase activity. Soybean seeds were procured from the Chikkapet market of Tumakuru, Karnataka State, India. Salivary amylase activity was estimated by the DNS method using maltose as standard. Amylase activity was found to be high at pH of 6.8 and a temperature of 37𫌱C. Amylase inhibition exhibited by different solvent extracts of soybean has been recorded (92% in aqueous extract, 93% in methanol extract, 98% in acid methanol extract) and inhibition concentration (aqueous, 45.73 μg; methanol, 34.26 μg; acid methanol, 18.20 μg).Total polyphenolic contents of various solvent extracts of soybean (0.29% in aqueous extract, 0.25% in methanol extracts and 0.27 % in acid methanol) might be the reason for the significant inhibition of amylase activity. Consequently, the results obtained in the present investigation can be considered as useful in controlling the digestion of complex sugars among the diabetic population by influencing the catalytic activity of salivary amylase.


Amylase, Soybean, Starch, Aqueous, Methanol, Acid Methanol, Extract.

Full Text:


Gutierrez, E., Wang, T. and Fehr, W. R. Quantification of sphingolipids in soybeans. J. Am. Oil Chem. Soc., 2004, 81, 737-742.

Arpana Kumari, Vinay Kumar Singh, Jorg Fitter, Tino Polen, C., Arvind M. Kayastha. α-amylase from germinating soybean (Glycine max) seeds-purification, characterization and sequential similarity of conserved and catalytic amino acid residues. Phytochem., 2010, 71, 1657-1666.

Groot, P. C., Bleeker, M. J., Pronk, J. C., Arwert, F., Mager, W. H., Planta, R. J. and Frants, R. R. Human pancreatic amylase is encoded by two different genes. Nucleic Acids Res., 1988, 16, 4724.

Lo Piparo, E., Scheib, H., Frei, N., Williamson, G., Grigorov, M. and Chou, C. J. Flavonoids for controlling starch digestion: structural requirements for inhibiting human α-amylase. J. Med. Chem., 2008, 51, 3555-3561.

Paloma Michelle de Sales, Paula Monteiro de Souza, Luiz Alberto Simeoni, Pérola de Oliveira Magalhães, Dâmaris Silveira. α-Amylase inhibitors: A review of raw material and isolated compounds from plant source. J. Pharm. Pharmaceut. Sci., 2012, 15, 141-183.

Brayer, G. D., Luo, Y. and Withers, S. G. The structure of human pancreatic α - amylase at 1.8 Å resolution and comparisons with related enzymes. Protein Sci., 1995, 4, 1730-1742.

Ramasubbu, N., Paloth, V., Luo, Y., Brayer, G. D. and Levine, M. J. Structure of human salivary α-amylase at 1.6 Å resolutions: Implications for its role in the oral cavity. Acta Crystallographica Section D: Biol. Crystallograp., 1996, 52, 435-446.

Dildar Ahmed, Qaria Mumtaz Mughal, Saba Younas and Muhammad Ikram. Study of phenolic content and urease and alpha-amylase inhibitory activities of methanolic extract of Rumex acetosella roots and its sub-fractions in different solvents. Pak. J. Pharm. Sci., 2013, 3, 553-559.

Rahul L. Gajbhiye, Anand Ganapathy and Parasuraman Jaisankar. A review of α-glucosidase and α-amylase Inhibitors for type 2 diabetes isolated from some important Indian medicinal plants. Ann. Clin. Pharmacol. Therap., 2018, 1, 1003.

Lankisch, M., Layer, P., Rizza, R. A. and DiMagno, E. P. Acute postprandial gastrointestinal and metabolic effects of wheat amylase inhibitor (WAI) in normal, obese and diabetic humans. Pancreas, 1998, 17, 176-181.

Vadivel, V. and Biesalshki, H. K. Total phenolic content, in vitro antioxidant activity and type II diabetes relevant enzyme inhibition properties of methanolic extract of traditionally processed underutilized food legumes, Acacia nilotica (L.) Wild ex. Delile. Int. Fd. Res. J., 2012, 19, 593-601.

Kenjiro Tadera, Yuji Minami, Kouta Takamatsu and Tomoko Matsuoka. Inhibition of α-glucosidase and α-amylase by flavonoids. J. Nutr. Sci. Vitaminol., 2006, 52, 146-153.

Mohsen Mobini-Dehkordi and Fahime Afzal Javan. Application of alpha-amylase in biotechnology. J. Biol. Today’s World. 2012, 1, 39-50.

Ishnava, K.B. and Motisariya, D.M. In-vitro study on α-amylase inhibitory activity of selected ethnobotanical plant extracts and its herbal formulations. Int. J. Pharmacogn. Chinese Med., 2018, 2, 136.

Jia, W., Gao, W. and Tang, L. Antidiabetic herbal drugs officially approved in China. Phytotherapy research: An international Journal Devoted to Pharmacological and Toxicological Evaluation of Natural Product Derivatives. 2003, 17, 1127-1134.

Boivin, M., Flourie, B., Rizza, R. A., Go, V. L. W. and DiMagno, E. P. Gastrointestinal and metabolic effects of amylase inhibition in diabetics. Gastroenterol., 1988, 94, 387-394.

Kokiladevi, E., Manickam, A. and Thayumanavan, B. Characterization of alpha-amylase inhibitor in Vigna sublobata. Bot. Bull. Acad. Sin., 2005, 46, 189-196.

Karishma Rajbhar, Himanshu Dawda and Usha Mukundan. Polyphenols: Methods of extraction. Sci. Revs. Chem. Commun., 2015, 5, 1-6.

Alghamdi, S. S., Khan, M. A., El-Harty, E. H., Ammar, M. H., Farooq, M. and Migdadi, H. M. Comparative phytochemical profiling of different soybean (Glycine max (L.) Merr) genotypes using GC-MS. Saudi J. Biol. Sci., 2018, 25, 15-21.

Kato, C. G., Gonçalves, G. D. A., Peralta, R. A., Seixas, F. A. V., De Sá-Nakanishi, A.B.,

Bracht, L. and Peralta, R. M. Inhibition of α-amylases by condensed and hydrolysable tannins: Focus on kinetics and hypoglycemic actions. Enz. Res., 2017, 1-12.

Luthria, D. L., Biswas, R. and Natarajan, S. Comparison of extraction solvents and techniques used for the assay of isoflavones from soybean. Fd. Chem., 2007, 105, 325-333.

Aleksandra Jovanovi, C., Predrag Petrovi, C., Verica Doroevi, C., Gordana Zduni, C., Katarina Savikin and Branko Bugarski. Polyphenols extraction from plant sources. Lekovite Sirovine., 2017, 37, 37-42.

Bernfeld, P. Amylases, α and β. Methods in Enzymology. Academic Press, New York. 1955, 149-158.

Chris Noel Timothy and Geetha, R. V. In vitro alpha-amylase and alpha-glucosidase inhibitory activity of the ethanolic extract of Lactuca sativa. Drug Invention Today, 2019, 11, 1890-1893.

Syed Bilal Shah, Lubna Sartaj, Fawad Ali, Syed Izhar Ali Shah and Muhammad Tahir Khan. Plant extracts are the potential inhibitors of α-amylase: A review. MOJ. Bioequiv. Availab., 2018, 5, 270-273.

Jacobsen, N., Lyche Melvaer, K. and Hensten-Pettersen, A. Some properties of salivary amylase: A survey of the literature and some observations. J. Dent. Res. Supplement., 1972, 2, 381-388.

Patrick Mc Cue, Young-In Kwon and Kalidas Shetty. Anti-diabetic and anti-hypertensive potential of sprouted and solid-state bio-processed soybean. Asia Pac. J. Clin. Nutr., 2005, 14, 145-152.

Douglas C. Doehlert and Stanley H. Duke. Specific determination of α-amylase activity in crude plant extracts containing β-amylase. Plant Physiol., 1983, 71, 229-234.

Sandstdt, R.M., Knen, E. and Bush, M.J. A standardized Wohlgemuth procedure for α-amylase activity. Cereal Chem., 1939, 16, 712-723.


  • There are currently no refbacks.