Promoting the Calcium-Uptake Bioactivity of Casein Phosphopeptides in vitro and in vivo

Guo Liu; Baoyan Guo; Shengwei Sun; Minna Luo; Fei Liu; Jianyin Miao; Jian Tang; Yahui Huang; Yong Cao; Mingyue Song

doi:10.3389/fnut.2021.743791

Promoting the Calcium-Uptake Bioactivity of Casein Phosphopeptides in vitro and in vivo

Front Nutr. 2021 Aug 30:8:743791. doi: 10.3389/fnut.2021.743791. eCollection 2021.

Authors

Guo Liu^{1

2}, Baoyan Guo^{1

2}, Shengwei Sun¹, Minna Luo¹, Fei Liu³, Jianyin Miao¹, Jian Tang⁴, Yahui Huang², Yong Cao¹, Mingyue Song¹

Affiliations

¹ Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, China.
² College of Horticulture, South China Agricultural University, Guangzhou, China.
³ Guangzhou Greencream Biotech Co., Ltd., Guangzhou, China.
⁴ Infinitus (China) Company Ltd., Guangzhou, China.

Abstract

Casein phosphopeptides have been studied widely for their ability to chelate calcium. However, systematic studies on the effects of casein phosphopeptides (CPP) on calcium absorption in vitro and in vivo are scarce. The purities of two commercially available products, CPP1 and CPP2, are 18.37 and 25.12%, respectively. Here, the in vitro calcium binding capacity of CPP2 was 142.56 ± 7.39 mg/g, which was higher than that of CPP1 (107.15 ± 6.27 mg/g). The calcium transport results in a Caco-2 monolayer model indicated that, relative to controls, CPP1 and CPP2 increased calcium transport by 21.78 and 53.68%, respectively. Subsequent animal experiments showed that the CPP2-Ca-H group (1% Ca, 0.4% CPP2) had significant increases in the femur index, serum Ca²⁺ and serum osteocalcin levels, and femoral Ca content. The CPP2-Ca-H animal also had decreased serum alkaline phosphatase levels, parathyroid hormone content, and urinary pyridinoline content. Overall, our results demonstrated that CPP2 had stronger effects on promoting calcium uptake than CPP1.

Keywords: Caco-2; animal model; calcium binding capacity; calcium uptake bioactivities; casein phosphopeptides.