Antioxidant and anti-inflammatory activities of the siamese crocodile (crocodylus siamensis) hemoglobin hydrolysate derived from trypsin and papain hydrolysis
Crocodylus siamensis hemoglobin hydrolysates (CHHs) were obtained by trypsin and papain
digestion at different incubation times (2, 4, 6 and 8 h) at 37 °C and subjected to antioxidant and
anti-inflammatory activity assessment. DPPH scavenging activity of CHH derived from trypsin
was similar to intact Hb. CHH derived from papain hydrolysis by 8-h hydrolysis (8h-CHHp)
showed the highest DPPH scavenging activity at 56.86% antioxidant inhibition with IC50 value
of 31 μg/ml. CHH derived from papain hydrolysis by 2-h hydrolysis (2h-CHHp) showed the
highest reducing power activity at 0.99 mM Trolox equivalent and 4h-CHHt showed reducing
activity at 0.16 mM Trolox equivalent (at concentration of 500 μg/ml). The linoleic peroxidation
activity of CHH derived from papain hydrolysis by 6-h hydrolysis (6h-CHHp) and CHH derived
from trypsin hydrolysis by 8-h hydrolysis (8h-CHHt) was increased in a dose-dependent manner
with IC50 value of 5 μg/ml. The strongest anti-inflammatory activity was found for 2h-CHHp,
which displayed a high efficacy in decreasing NO production of macrophage RAW 264.7 cells
(46.86%) with no toxicity and significantly reduced pro-inflammatory cytokines interleukin-6
(IL-6) production to about 25.73 pg/ml. Taken collectively, the results of this work demonstrate
that CHHs derived from papain hydrolysis possesses antioxidant and anti-inflammatory activities,
which provides support for the application against inflammation and oxidative stress-related
disorders.