The Bioactive Compound Contents and Potential Protective Effects of Royal Jelly Protein Hydrolysates against DNA Oxidative Damage and LDL Oxidation.

Shu-Hua Chiang,Kia-Min Yang,Shiann-Cherng Sheu,Chih-Wei Chen

doi:10.3390/antiox10040580

Abstract

In this study, the inhibition of DNA oxidative damage and low-density lipoprotein (LDL) oxidation of royal jelly protein (RJP) hydrolysates obtained from two commercial proteases were investigated. The results showed that the inhibition of DNA oxidative damage induced by the Fenton reaction, RJP, RJPs hydrolyzed by alcalase (RJP-A), RJPs hydrolyzed by flavourzyme (RPJ-F) and RJP two-stage hydrolysates (RPJ-AF) all had the effect of inhibiting deoxyribose oxidative damage. The inhibition effect of RJP, RJP-A, RJP-F and RJP-AF (1.0 mg/mL) were 47.06%, 33.70%, 24.19% and 43.09%, respectively. In addition, studies have also found that both RJP and RJP hydrolysates can reduce the production of 8-OH-2′-dG and the order of its inhibitory ability is RJP-AF ≒ RJP-A > RJP-F > RJP. The inhibition of DNA damage induced by bleomycin-Fe3+/ascorbic acid (Asc) with the addition of RJP, RJP-A, RPJ-F and RPJ-AF were 17.16%, 30.88%, 25.00% and 37.25%, respectively. The results of LDL oxidation inhibition showed that RJP-AF (1 mg/mL) not only had the most effective inhibitory Cu2+-induced LDL oxidation to produce a thiobarbituric acid reactive substance (TBARS) but also extended the lag time of conjugated diene formation to 300 min, which was 3.3 times that of the control group.

Highlights

Functional foods contain health-promoting compounds as well as traditional nutrients [1]
The results showed that the royal jelly protein (RJP)-AF contained the most necessary amino acids including the basic amino acid (BAA), His (94.73 nmole/mL), Arg (105.22 nmole/mL), Lys (487.93 nmole/mL); the branched chain amino acid (BCAA), Val (48.27 nmole/mL), Leu (102.48 nmole/mL), Ile
We reported that RJP and RJP hydrolysates showed significant contents of flavonoids and phenolic acids (Table 1) and that RJP and RJP hydrolysates showed significance against DNA oxidative damage and low-density lipoprotein (LDL) oxidation (Tables 3–5; Figures 2–4). 10-Hydroxydec-2-Enoic Acid (10-HDA) is only found in Royal jelly (RJ) so it has been used as a quality marker of royal jelly products [35,36]

Summary

Introduction

Functional foods contain health-promoting compounds as well as traditional nutrients [1]. The value of functional foods can be enhanced by adding bioactive peptides, polyunsaturated fatty acids, probiotics and/or prebiotics [2]. Protein hydrolysate is a mixture of peptides, free amino acids and other proteases. Royal jelly (RJ) is an attractive ingredient in healthy foods and has for some time been in use commercially. It is the sole food for the queen honeybee [4] and of the honeybee larva and is present in the secretions from the hypopharyngeal and mandibular glands of 2 to 12 day old adult workers [5,6,7].

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Discussion

Conclusion