(P23-060-23) The Inhibitory Potential on Myostatin Expression Levels of Novel Peptide Fractions From Mealworm (Tenebrio molitor Larva) in C2C12 Cells

Objectives: Skeletal muscle atrophy refers to wasting muscle mass. Myostatin (GDF-8) is a key negative regulator of skeletal muscle mass. Mealworm (Tenebrio molitor larva) is an edible insect with nutritional value, providing rich protein and branched-chain amino acids (BCAAs). Recently, bioactive peptides have received attention as alternative chemotherapeutic agents by improving physiological functions. This study aimed to investigate the novel peptide fractions from mealworms that inhibit myostatin expression levels in C2C12 cells.

Methods: Mealworm protein isolate (MPI) was obtained at alkaline pH, and its hydrolysate (MPH) was prepared with flavourzyme and alcalase. MPH was separated by ultrafiltration membranes (3kDa< , 3kDa< < 10kDa, 10kDa< ). The MT (10kDa< ), which has the most significant myostatin inhibitory potential, was fractionated (D1-D4) by the anion exchange column (DEAE) chromatography. The D1 was used for further purification on the C18 column by RP-HPLC and separated into five fractions (C1-5). Luciferase activity was evaluated to investigate the myostatin promoter activity. Real-time polymerase chain reaction and immunoblotting were performed to determine mRNA and protein expression levels of myostatin.

Results: Treatment of the D1 lowered the luciferase activity (17.17%) compared to the control group. The D1 had the lowest mRNA (33.78%) and protein level of myostatin among all D- fractions. Furthermore, treatment of the D1 significantly decreased the luciferase activity (2.31-fold), mRNA (2.03-fold), and protein expression levels of myostatin compared to those of the MT. Treatment of the C3 also significantly decreased the luciferase activity (27.68%) in comparison to the control group. Additionally, the C3 had the lowest mRNA (64.65%) and protein level of myostatin among all C- fractions. Treatment of C3 significantly reduced the luciferase activity (1.76-fold), mRNA (2.30-fold), and protein expression levels of myostatin compared to those of the D1.

Conclusions: The most positively charged protein fraction (D1) and C3 from the RP-HPLC have significant inhibitory potential for myostatin expression. The peptide identification of the C3 and in vivo study can be evaluated for future research.

Funding Sources: This research was supported by the Rural Development Administration, Republic of Korea (Project No. PJ015912022023).