In vitro Antioxidant, Cytotoxic and Antidiabetic Activity of Protein Hydrolysates Prepared from Chinese Pond Turtle (Chinemys reevesii)

Abstract

Research background. Cardiovascular diseases and diabetes are the biggest causes of death globally. Bioactive peptides derived from many food proteins using enzymatic proteolysis and food processing perform a positive impact on the prevention of these diseases. The bioactivity of grass turtle muscle proteins and their enzymatic hydrolysates has not received much attention, thus this study aims to investigate the antioxidant, antidiabetic, and cytotoxic activities of the enzymatic hydrolysates of grass turtle muscle protein. Experimental approach. Grass turtle muscle(s) was hydrolysed using four proteolytic enzymes (Alcalase (AH), Flavourzyme (FH), Trypsin (TH), and Bromelain (BH)). The degree of hydrolysis was measured. High performance liquid chromatography (HPLC) was conducted to explore their amino acid profiles and molecular mass distribution of the hydrolysates. The antioxidant activities were evaluated using various in vitro tests, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), Hydroxyl radical (•OH) radical scavenging activities, reducing capacity, chelating (Fe2+), and lipid peroxide inhibition activity. Antidiabetic activity was evaluated against α-amylase inhibition and α-Glucosidase inhibition assay. Besides, cytotoxic effect of hydrolysates on human colon cancer (HT-29) cells was assessed. Results and conclusions. The amino acid composition of the hydrolysates revealed that higher contents of glutamic, aspartic, lysine, hydroxyproline, and hydrophobic amino acids. AH showed significantly the highest inhibition of lipid peroxidation. FH showed the highest lipid peroxidation, strongest radical scavenging activity of DPPH (68.32 %), ABTS (74.12 %), FRAP (0.30 unit), α-glucosidase (61.80 %) and cytotoxic effect on cancer cells (82.26 %) at 550 µg/mL for HT-29 cell line. TH and BH were showed significant (p<0.05) hydroxyl radical activity (92.70 %) and Fe2+ metal chelating (63.29 %), respectively. The highest α-amylase (76.89 %) inhibition was recorded by BH and FH. Novelty and scientific contribution. Enzymatic grass turtle muscle(s) proteins hydrolysates achieved great antioxidant, cytotoxic, and antidiabetic activity. The findings of this study indicated that the bioactive hydrolysates /peptides from grass turtle muscle(s) protein could be potential candidate as ingredients in pharmaceuticals and functional food formulations.

Influence of the Enzymatic Hydrolysis Using Flavourzyme Enzyme on Functional, Secondary Structure, and Antioxidant Characteristics of Protein Hydrolysates Produced from Bighead Carp (Hypophthalmichthys nobilis)

“…However, no significant variation was noted when the enzyme/substrate ratio was increased to 5%, which may cause enzyme aggregation, inhibit protein substrate diffusion, and finally decrease the enzymatic hydrolysis process because of the lack of catalytic sites of the targeted enzyme [ 8 ]. Serajul Islam and others found that the optimum E/S% for the flavourzyme enzyme to obtain protein hydrolysates from a Chinese pond turtle substrate was 4% [ 17 ]. Moreover, the effect of pH on the DH was studied and displayed in Figure 1 B.…”

Obtención de aislados e hidrolizados proteicos de Teff (Eragrostis tef (Zuccagni) Trotter) y evaluación de su actividad antioxidante

“…De acuerdo con Niño et al (2019), la actividad antioxidante está relacionada con las secuencias peptídicas que se liberan durante la hidrolisis, debido a que entre más pequeño sea el péptido mayor actividad tendrá. También su actividad biológica puede estar relacionada con la composición de aminoácidos, el grado de hidrolisis y la distribución de los péptidos donantes de electrones capaces de reaccionar con los radicales libres para así poder convertirlos en productos más estables (Islam et al, 2021). Por otro lado, en la Fig.…”

Biogenic Elements and Heavy Metals in Hermann’s Tortoises—Testudo hermanni: Effect on Serum Biochemistry and Oxidative Status Parameters

“…For the parameter FRAP, there has only been one study published, which was carried out on the Chinemys reevsesii species of turtle. Islam et al [ 81 ] evaluated FRAP in muscle cells after killing the animals. The final values of FRAP were only shown in figures of evaluated absorbance (A 700nm = 0.300) in comparison with our results (297.70 µmoL Fe 2+ /g TP), and because of this it is impossible to compare these studies.…”