title: In silico, in vitro and in vivo analyses of dipeptidyl peptidase IV inhibitory activity and the antidiabetic effect of sodium caseinate hydrolysate.
abstract: The frequency (A), a novel in silico parameter, was developed by calculating the ratio of the number of truncated peptides with Xaa-proline and Xaa-alanine to all peptide fragments from a protein hydrolyzed with a specific protease. The highest in vitro DPP-IV inhibitory activity (72.7%) was observed in the hydrolysate of sodium caseinate by bromelain (Cas/BRO), and the constituent proteins of bovine casein also had relatively high A values (0.10-0.17) with BRO hydrolysis. 1CBR (the <1 kDa fraction of Cas/BRO) showed the greatest in vitro DPP-IV inhibitory activity of 77.5% and was used for in vivo test by high-fat diet-fed and low-dose streptozotocin-induced diabetic rats. The daily administration of 1CBR for 6 weeks was effective to improve glycaemic control in diabetic rats. The results indicate that the novel in silico method has the potential as a screening tool to predict dietary proteins to generate DPP-IV inhibitory and antidiabetic peptides.
authors.affiliation: Department of Health Nutrition and Biotechnology, Asia University, 500 Lioufeng Road, Wufeng, Taichung 41354, Taiwan.
authors.forename: Cheng-Hong
authors.initials: CH
authors.lastname: Hsieh
authors.affiliation: Division of Endocrine and Metabolism, China Medical University Hospital, 2 Yude Road, Taichung, 40447, Taiwan.
authors.forename: Tzu-Yuan
authors.initials: TY
authors.lastname: Wang
authors.affiliation: Food Safety and Inspection Center, Asia University, 500 Lioufeng Road, Wufeng, Taichung 41354, Taiwan and Department of Nutrition, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan. kchsu@mail.cmu.edu.tw.
authors.forename: Chuan-Chuan
authors.initials: CC
authors.lastname: Hung
authors.affiliation: Department of Food and Beverage Management, Tung Fang Design Institute, 110 Dongfang Road, Kaohsiung 82941, Taiwan.
authors.forename: Chia-Ling
authors.initials: CL
authors.lastname: Jao
authors.affiliation: Department of Health Nutrition and Biotechnology, Asia University, 500 Lioufeng Road, Wufeng, Taichung 41354, Taiwan.
authors.forename: You-Liang
authors.initials: YL
authors.lastname: Hsieh
authors.affiliation: Department of Nutrition, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan. kchsu@mail.cmu.edu.tw.
authors.forename: Si-Xian
authors.initials: SX
authors.lastname: Wu
authors.affiliation: Department of Health Nutrition and Biotechnology, Asia University, 500 Lioufeng Road, Wufeng, Taichung 41354, Taiwan and Food Safety and Inspection Center, Asia University, 500 Lioufeng Road, Wufeng, Taichung 41354, Taiwan and Department of Nutrition, China Medical University, 91 Hsueh-Shih Road, Taichung 40402, Taiwan. kchsu@mail.cmu.edu.tw.
authors.forename: Kuo-Chiang
authors.initials: KC
authors.lastname: Hsu
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001963:Bromelains / Q000378:metabolism; D002364:Caseins / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy*; D059305:Diet, High-Fat; D018819:Dipeptidyl Peptidase 4 / Q000378:metabolism; D054873:Dipeptidyl-Peptidase IV Inhibitors / Q000494:pharmacology*; D010450:Endopeptidases / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D008297:Male; D010446:Peptide Fragments / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin
chemical_list: D001786:Blood Glucose; D002364:Caseins; D054873:Dipeptidyl-Peptidase IV Inhibitors; D007004:Hypoglycemic Agents; D010446:Peptide Fragments; D013311:Streptozocin; D001963:Bromelains; D010450:Endopeptidases; D018819:Dipeptidyl Peptidase 4