Cowpea seed extracts have been investigated for its antioxidant potentials, enzyme-inhibitory activities, antifungal and nematocidal properties among others. Also, protein hydrolysates of cowpea seeds have been evaluated for its antioxidant and antihypertensive potentials in vitro. However, there has been relative paucity of information on the α-amylase inhibitory activities of cowpea seed protein hydrolysates. Consequently, this study evaluated the α-amylase – inhibitory activities and antioxidant potentials of protein hydrolysates derived from cowpea seed proteins. Cowpea seeds were defatted using n-hexane and proteins were extracted from the resulting seed meal. The proteinases namely pepsin and trypsin were used for protein hydrolysis and the resulting hydrolysates were investigated for antioxidant properties (using hydrogen peroxide and ferric ions) and α-amylase inhibitory activity. Antioxidant assays indicated that hydrolysates derived from trypsin digestion showed better ferric reducing power even as both hydrolysates demonstrated similar hydrogen peroxide scavenging capacities. α-amylase inhibition studies showed that peptic hydrolysates had better inhibitory activity (IC50 = 0.127±0.012 mg/ml). Kinetic data indicated mixed mode of inhibition for both hydrolysates, with peptic hydrolysates showing higher binding affinity (ki = 0.089 mg/ml). It is suggested that proteins from cowpea might encode certain peptides with potent biofunctionalities beyond their nutritional benefits and as such could be further processed to develop novel anti-diabetic agents and food additives.
Piero, M. N., Nzaro, G. M. and Njagi, J. M. (2014). Diabetes mellitus – a devastating metabolic disorder. Asian Journal of Biomedical and Pharmaceutical Sciences; 04 (40), 1-7.
Arise, R. O., Yekeen, A. A. and Ekun, O. E. (2016b). In vitro antioxidant and α-amylase inhibitory properties of watermelon seed protein hydrolysates. Environmental and Experimental Biology. 14: 163–172.
Yu, Z., Liu, B., Zhao, W., Yin, Y., Liu, J. and Chen, F. (2012). Primary and secondary structure of novel ACE-inhibitory peptides from egg white protein. Food Chem. 133: 315–322.
Wang, L., Zhang, X. T., Zhang, H. Y., Yao, H. Y. and Zhang, H. (2010). Effect of Vaccinium bracteatum Thunb. leaves extract on blood glucose and plasma lipid levels in streptozotocin-induced diabetic mice. J Ethnopharmacol. 130: 465–469.
Liu, S., Wang, W., Zhang, J., Yang, X., Lee, E. T., He, Y., Piao, J., Yao, C., Zeng, Z., Howard, B. V., Fabsitz, R. R. and Best, L. (2011). Prevalence of diabetes and Impaired Fasting glucose in Chinese adults. China National Nutrition and Health Survey, 2002. Preventing Chronic Disease 8 (1); A13.
Chandra, K., Salman, A. S., Mohd, A., Sweety, R. and Ali, K. N. (2015). Protection Against FCA Induced Oxidative Stress Induced DNA Damage as a Model of Arthritis and In vitro Anti-arthritic Potential of Costus speciosus Rhizome Extract. www.ijppr.com International Journal of Pharmacognosy and Phytochemical Research; 7 (2); 383-389.
Halliwell, B. (2007). "Oxidative stress and cancer: have we moved forward?" (PDF). Biochem. J. 401 (1): 1–11.
Valko, M., Leibfritz, D., Moncol, J., Cronin, M. T., Mazur, M. and Telser, J. (2007). "Free radicals and antioxidants in normal physiological functions and human disease". International Journal of Biochemistry & Cell Biology 39 (1): 44–84.
Pohanka, M (2013). "Alzheimer´s disease and oxidative stress: a review". Current Medicinal Chemistry 21 (3): 356–364.
Dean, O. M., van den Buuse, M., Berk, M., Copolov D. L., Mavros, C. and Bush, A. I. (2011). "N-acetyl cysteine restores brain glutathione loss in combined 2-cyclohexene-1-one and D-amphetamine-treated rats: relevance to schizophrenia and bipolar disorder". Neurosci Lett. 499 (3): 149–53.
Ramond A., Godin-Ribuot, D., Ribuot, C., Totoson. P., Koritchneva, I., Cachot, S., Levy, P. and Joyeux-Faure, M. (2011). "Oxidative stress mediates cardiac infarction aggravation induced by intermittent hypoxia." Fundam Clin Pharmacol. 27 (3): 252–261.
Diego-Otero Y., Romero-Zerbo Y., el Bekay, R., Decara, J., Sanchez, L., Rodriguez-de Fonseca, F. and del Arco-Herrera, I. (2009). "Alpha-tocopherol protects against oxidative stress in the fragile X knockout mouse: an experimental therapeutic approach for the Fmr 1 deficiency." Neuropsychopharmacology 34 (4): 1011–26.
Amer, J., Ghoti, H., Rachmilewitz, E., Koren, A., Levin, C. and Fibach, E. (2006). "Red blood cells, platelets and polymorphonuclear neutrophils of patients with sickle cell disease exhibit oxidative stress that can be ameliorated by antioxidants". British Journal of Haematology 132 (1): 108–113.
Rahimi-Madiseh, M., Malekpour-Tehrani, A., Bahmani, M. and Rafieian-Kopaei M. (2016). The research and development on the antioxidants in prevention of diabetic complications. Asian Pacific Journal of Tropical Medicine 9 (9): 825–831.
Segura-Campos, M. R., Guerrero, L. A and Ancona, D. A. (2010). Angiotensin-I converting enzyme inhibitory and antioxidant activities of peptide fractions extracted by ultrafiltration of cowpea Vigna unguiculata hydrolysates, J Sci Food Agric. 90: 2512–2518.
Gupta, P., Singh, R., Malhotra, S., Boora, K. S. and Singal H. R. (2010). Characterization of seed storage proteins in high protein genotypes of cowpea [Vigna unguiculata (L.) Walp.] Physiol. Mol. Biol. Plants, 16 (1): 53-58.
Ofuya, Z. M. and Akhidue, V. (2005). The role of pulses in human nutrition: a review. Journal of Applied Science & Environment Management 9 (3): 99-104.
Freitas, R. L, Teixeira, A. and Ferreira, R. B. (2004). Characterization of the proteins from Vigna unguiculata seeds. J Agr Food Chem 52 (6): 1682–7.
Lopez-Barrios, L., Gutierrez-Uribe, J. A. and Serna-Saldıvar, S. O. (2014). Bioactive Peptides and Hydrolysates from Pulses and Their Potential Use as Functional Ingredients. Journal of Food Science 79 (3) 273-283.
Ilesanmi J. O. and Gungula D. T. (2016). Amino Acid Composition of Cowpea Grains Preserved With Mixtures OF Neem (Azadirachta indica) and Moringa (Moringa oleifera) Seed Oils American Journal of Food and Nutrition, 4 (6): 150-156.
Zia-Ul-Haq, M., Ahmad, S., Amarowicz, R. De Feo, V. (2013). Antioxidant Activity of the Extracts of Some Cowpea (Vigna unguiculata (L) Walp.) Cultivars Commonly Consumed in Pakistan. Molecules. 18, 2005-2017.
Agarwal K. L. and Jain, A. K. (2010). Alpha-amylase Inhibitor Formulation Development Using Cowpea: A Novel Entities. International Journal of Pharmaceutical Studies and Research 1 (2); 64-71
Ahmad, S., Akhter, M., Zia-Ul-Haq, M. and Mehjabeen, A. S. (2010). Antifungal and nematicidal activity of selected legumes of Pakistan. Pak. J. Bot. 42, 1327–1331.
Segura-Campos, M. R., Chel-Guerrero L. A. and Betancur-Ancona, D. A. (2011). Purification of angiotensin I-converting enzyme inhibitory peptides from a cowpea (Vigna unguiculata) enzymatic hydrolysate. Proc Bioch 46 (4): 864–72.
Segura-Campos MR, Chel-Guerrero LA, Betancur-Ancona DA. (2013). Vigna unguiculata as source of angiotensin-I converting enzyme inhibitory and antioxidant peptides. In: Hernandez-Ledesma B, Chia-Chien H, editors. Bioactive food peptides in health and disease. Rijeka, Croatia: InTech. p 184–204.
Wani, A. A., Sogi, D. S., Singh, P., Wani, I. A. and Shivhare, U. S. (2011). Characterisation and Functional Properties of Watermelon (Citrullus lanatus) Seed Proteins. Journal of Agricultural and Food Chemistry 91: 113-121.
Alashi, A. M., Blanchard, C. L., Mailer, R. J., Agboola, S. O., Mawson, A. J., He, R., Malomo, S. A., Girgih, A. T. and Aluko, R. E. (2014). Blood pressure lowering effects of Australian canola protein hydrolysates in spontaneously hypertensive rats. Food Research International 55: 281-287.
Udenigwe, C. C., Lin, Y., Hou, W. and Aluko, R. E. (2009). Kinetics of the inhibition of renin and angiotensin I-converting enzyme by flaxseed protein hydrolysate fractions. Journal of Functional Foods I: 199- 207.
Arise, R. O., Yekeen, A. A., Ekun, O. E. and Olatomiwa, O. J. (2016a). Angiotensin-I converting enzyme-inhibitory, antiradical and hydrogen peroxide-scavenging properties of Citrullus lanatus seed protein hydrolysates. Ceylon J. Sci. 45: 39–52.
Ali, H., Houghton, P. J., Soumyanath, A. (2006). Alpha-amylase inhibitory activity of some Malaysian plants used to treat diabetes, with particular reference to Phyllanthus amarus. J. Ethnopharmacol. 107: 449–455.
Keser, S., Celik, S., Turkoglu, S., Yilmaz, O. and Turkoglu, I. (2012). Hydrogen peroxide radical scavenging and total antioxidant activity of hawthorn. Chemistry Journal 02 (01): 9-12.
Girgih, A. T., Udenigwe, C. C., Li, H., Adebiyi, A. P. and Aluko, R. E. (2011). Kinetics of enzyme inhibition and antihypertensive effects of hemp seed (Cannabis sativa L.) protein hydrolysates. Journal of the American Oil Chemists' Society 88: 1767-1774.
Zhang, S. B., Wang, Z. and Xu, S. Y. (2008). Antioxidant and antithrombotic activities of rapeseed peptides. J. Am. Oil Chem. Soc. 85: 521–527.
Isleib, T., Patte, H., Sanders, T., Hendrix, K. and Dean, L. (2006). Compositional and sensory comparision between normal and high oleic peanuts. J. Agric. Food Chem., 54: 179-1763.
Pedroche, J., Yust, M. M., Lqari, H., Giron-Calle, J., Alaiz, M., Vioque, J., Millan, F. (2004) Brassica carinata protein isolates: chemical composition, protein characterization and improvement of functional properties by protein hydrolysis. Food Chem 88 (3): 337–346.
Voet, D. and Voet, J. (2011). Biochemistry (4th ed.). John Wiley & Sons. pp. 168-169.
Jamdar, S. N., Rajalakshmi, V., Pednekar, M. D., Juan, F., Yardi, V. and Sharma, A. (2010) Influence of degree of hydrolysis on functional properties, antioxidant activity and ACE inhibitory activity of peanut protein hydrolysate. Food Chem., 121, 178–184.
Malomo S., Onuh J., Girgih A., Aluko R. (2015). Structural and antihypertensive properties of enzymatic hemp seed protein hydrolysates. Nutrients 7: 7616–7632.
Yu Z, Yin Y, Zhao W, Liu J, Chen F (2012) Anti-diabetic activity peptides from albumin against a-glucosidase and a-amylase. Food Chem 135 (3): 2078–2085.
Garza, N. G., Koyoc, J. A., Castillo, J. A., Zambrano, E. A., Ancona, D. B., Guerrero, L. C., Garcia, S. R. (2017). Biofunctional properties of bioactive peptide fractions from protein isolates of moringa seed (Moringa oleifera). J Food Sci. Technol. s13197-017-2898-8.
Irshad, M., Anwar, Z., Gulfraz, M., Butt, H. I., Ejaz A. and Nawaz, H. (2012) Purification and characterization of α-amylase from Ganoderma tsuage growing in waste bread medium African Journal of Biotechnology 11 (33), 8288-8294.
Acharya, D. K., Shah, I. J., Gami, P. N. and Shukla, R. M. (2014). Optimization for α-amylase production by Aspergillus oryzae using submerged fermentation technology. Basic Research Journal of Microbiology 1 (4): 01-10.
Razali, A. N., Amin, A. M. and Sarbon, N. M. (2015). Antioxidant activity and functional properties of fractionated cobia skin gelatin hydrolysate at different molecular weight. International Food Research Journal 22 (2): 651-660.
Udenigwe, C. C. and Aluko, R. E. (2011). Chemometric analysis of the amino acid requirements of antioxidant food protein hydrolysates. International Journal of Molecular Sciences, 12, 3148–3161.
Li, Y. and Li, B. (2013). Characterization of structure–antioxidant activity relationship of peptides in free radical systems using QSAR models: Key sequence positions and their amino acid properties. Journal of Theoretical Biology 318: 29–43.
Naik, P. (2012). Protein metabolism. In: Essentials of Biochemistry. Jaypee Brothers Medical Publishers, pp. 226–257.
Rahman, T., Hosen, I., Islam, M. M. and Shekhar, H. U. (2012). Oxidative stress and human health. Advances in Bioscience and Biotechnology, 3: 997-1019.
Umayaparvathi, S., Arumugam, M., Meenakshi., S. and Balasubramanian, T. (2015). Antioxidant Properties of Protein Hydrolysate Obtained from Oyster Saccostrea cucullata (Born, 1778), Journal of Aquatic Food Product Technology, 24: 5, 502-51.