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

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

doi:10.3389/fnut.2021.743791

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.

Highlights

The element calcium is an essential mineral nutrient for maintaining the good health of humans [1]
There has been much work in investigating casein phosphopeptides in recent years, few studies have systematically examined in vitro and in vivo calcium absorption. We sought to both characterize casein phosphopeptides and evaluate their in vitro and in vivo calcium absorption efficiencies. Their calcium binding capacities were examined in a sodium phosphate buffer, the calcium transport in Caco-2 cell monolayer model, and the bone metabolism in an animal model
The results revealed that the purity of CPP2 was much higher than that of CPP1 after optimizing the production method

Summary

INTRODUCTION

The element calcium is an essential mineral nutrient for maintaining the good health of humans [1]. The development of a better form of calcium that can overcome low absorption and bioavailability has become an important research topic Both amino acid calcium complex and small peptide calcium chelate can be directly absorbed in the human body [8]. Casein phosphopeptides possess the capacity to chelate Ca2+ and avoid the precipitation of calcium phosphate salts Due to this, they have been considered desired mineral carriers that have a potential role in strengthening elemental mineral absorption, which can, in turn, promote good health [17]. We sought to both characterize casein phosphopeptides and evaluate their in vitro and in vivo calcium absorption efficiencies As such, their calcium binding capacities were examined in a sodium phosphate buffer, the calcium transport in Caco-2 cell monolayer model, and the bone metabolism in an animal model. This study provides basic theoretical research for the evaluation of casein phosphopeptides and provides useful information for the optimization of production processes

MATERIALS AND METHODS

Feeding Procedures

AND DISCUSSION

Findings

ETHICS STATEMENT