Harshita Arora | ALES Graduate Seminar

A graduate exam seminar is a presentation of the student’s final research project for their degree.
This is an ALES MSc Final Exam Seminar by Harshita Arora. This seminar is open to the general public to attend.

Thesis Topic: Pea protein derived bioactive peptides stimulate bone health promoting effects

MSc with Dr. Jianping Wu

Seminar Abstract:

Osteoporosis is a bone disease affecting 1 in 3 women and 1 in 5 men in Canada. One possible approach to prevent this disease is to stimulate the activity of osteoblasts (bone forming cells) using food protein-derived bioactive peptides. As a sought-after plant protein, we previously identified a tripeptide LRW (Leu-Arg-Trp). The first objective of this thesis was to investigate the osteogenic activity of LRW using pre-osteoblast MC3T3-E1 cells.

LRW treatment (at 50 μM) caused a significant increase in cell proliferation (4-fold increase), stimulated differentiation by increased the levels of type 1 collagen (COL1 A2: (3-fold increase), alkaline phosphatase (2-fold increase), runt-related transcription factor 2 (2-fold increase), and phospho-Akt (2.5-fold increase), as well as promoted mineralization evidenced by Alizarin-S red staining and nodule formation. LRW treatment also decreased receptor activator of nuclear factor kappa B-ligand (1-fold decrease) and increased osteoprotegrin levels (2-fold increase), thereby decreasing bone resorption. Furthermore, LRW also significantly increased the wound healing based on by cell migration assay.

Since LRW was identified from pea protein hydrolysate, the second objective of the thesis was to determine the osteoblastic activity of pea protein hydrolysates using human osteoblast cells (U-2OS). Among seven pea protein hydrolysates prepared, three prepared with chymotrypsin, thermolysin and alcalase showed better ability to increase the level of COL1 A2 and thus selected for further study. Pea protein hydrolysate up-regulated COL1 A2 (2-fold increase), procollagen (1.25-fold increase), nuclear factor erythoid 2- related factor 2 levels (1.35-fold increase), C-X-Chemokine receptor type 4 (CXCR4) (2-fold increase) and signal transducer and activator of transcription 3 (STAT3) (1.5-fold increase) in alcalase prepared hydrolysate. Furthermore, increased mRNA and protein expression of STAT3 (3.5-fold increase) and CXCR4 (4-fold increase) in alcalase prepared sample were further validated by qRT-PCR. Pea protein hydrolysate also decreased the levels of matrix metalloproteinase MMP-1 and MMP-9 expression, indicating the inhibitory role on the degradation of bone matrix.

This research demonstrated the presence of bioactive peptides in pea protein that can positively modulate the activity of osteoblasts, indicating the potential of pea-derived peptides for the prevention or treatment of osteoporosis.