According to the World Health Organization (WHO), more than 1.13 billion people in the world are suffering from hypertension and less than 20% of them receive proper treatment. The renin−angiotensin−aldosterone system (RAS) is responsible for regulating human blood pressure and maintaining cardiovascular function. Overactivation of RAS is one of the main pathologies of hypertension. Angiotensin converting enzyme (ACE) can catalyse the release of effective vasoconstrictors (angiotensin II: Ang II), so, suppression of ACE is widely used for treatment of hypertension.

Collagen and gelatin are a source of peptides with ACE inhibitory activity with some peptides from bovine bone, pig skin, fishbone, etc. having previously been successfully identified. However, inhibitory peptides have yet to been shown to have antihypertensive effects in vivo. Consequently, studying the effects and mechanisms of these peptides on hypertension and hypertension complications in vivo is required.

This study aims to investigate the effects and mechanisms of bovine bone gelatin-derived peptides (BGPs) on hypertension and hypertension complications in spontaneously hypertensive rats (SHRs). Initially, it was found that BGPs can significantly reduce blood pressure, triglyceride levels, and the low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio in SHRs. Next, many peptides with inhibitory effects were identified and it was found that amino acid sequence and structure of peptides were closely related to their ACE inhibitory effect. Interestingly, 56.8% of the identified peptides in BGP contained hydroxyproline residues, which has been shown to have an irreplaceable effect on the ACE inhibitory effect.

How was PEAKS used?

Peptide sequence analysis was performed by de novo sequencing in PEAKS Studio 8.5 software. Hydroxyproline (P, 15.97) and methionine (M, 15.99) were selected as two variable modifications (PTMs). The protein sources of peptides obtained from PEAKS Studio 8.5 was determined by BLAST.

A total number of 162 peptides with average local confidence ≥70% were identified from BGPs using PEAKS Studio 8.5. Most of the polypeptide sequences in BGPs contain 6−10 amino acid residues, of which 35.19% of the polypeptide molecular weight is in the range of 600−700 kDa and 27.78% is in the range of 800−900 kDa.

Cao, Songmin, et al. “Bovine Bone Gelatin-Derived Peptides: Food Processing Characteristics and Evaluation of Antihypertensive and Antihyperlipidemic Activities.” Journal of Agricultural and Food Chemistry 70.32 (2022): 9877-9887. https://doi.org/10.1021/acs.jafc.2c02982

Abstract

This study aimed to evaluate the food processing properties of bovine bone gelatin-derived peptides (BGPs) and their effects and mechanisms on hypertension and hypertension complications in spontaneously hypertensive rats (SHRs). BGPs had good acid, high temperature, and NaCl resistance abilities in vitro. Additionally, Maillard reaction of BGPs with low-dose reducing sugar (≤15%) exhibited a free radical scavenging effect. BGPs significantly reduced the blood pressure, triglyceride levels, and the low-density lipoprotein cholesterol/high-density lipoprotein cholesterol ratio in SHRs through downregulated angiotensin converting enzyme (ACE), angiotensin II (Ang II), and Ang II type 1 receptor (AT1R) levels and the upregulated Ang II type 2 receptor (AT2R) level. In brief, BGP could alleviate hypertension and dyslipidemia in SHRs by inhibiting ACE/Ang II/AT1R and activating the Ang II/AT2R signaling pathway. Our study suggests that BGP has good food processing properties and could be a potential nutraceutical for antihypertensive and antihyperlipidemic issues.