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Collagen peptide from Acaudina molpadioides (AMP) showed antioxidative activity in H2O2‐induced RAW264.7 cells in our pervious study. In this study, it was observed that AMP could effectively improve the morphology and function of liver in CCl4‐induced mice. After 200 mg/kg AMP treatment, the content of MDA in liver decreased by 62.3%, and the level of antioxidant enzymes (SOD, GSH‐Px, and CAT) increased by more than 65%. Western blot results disclosed that AMP (200 mg/kg) upregulated the Nrf2 level by 73.8% and downregulated Keap1 by 41.0% in CCl4‐induced mice liver. The levels of p‐ERK, p‐JNK, and p‐p38 in 200 mg/kg AMP treatment groups decreased by 57.3%, 40.9%, and 40.6%, but the levels of p‐PI3K and p‐AKT increased by 162.6% and 60.3%, respectively. Furthermore, the trends of Nrf2, Keap1, p‐ERK, p‐JNK, p‐p38, p‐PI3K, and p‐AKT levels in H2O2‐induced RAW264.7 cells after AMP treatment were similar to the results in CCl4‐induced mice liver. These findings provided evidence that AMP exerted antioxidant activity via Keap1/Nrf2‐ARE, PI3K/AKT, and MAPKs pathways in vivo and in vitro. Therefore, the collagen peptide from A. molpadioides might represent a novel functional food to prevent acute liver injury via attenuation of oxidative stress. [ABSTRACT FROM AUTHOR]

Enantiopure epoxides are versatile synthetic intermediates for producing optically active pharmaceuticals. In an effort to provide more options for the preparation of enantiopure epoxides, a variant of the epoxide hydrolase (vEH-Am) gene from a marine microorganism Agromyces mediolanus was synthesized and expressed in Escherichia coli. Recombiant vEH-Am displayed a molecular weight of 43 kDa and showed high stability with a half-life of 51.1 h at 30 °C. The purified vEH-Am exhibited high enantioselectivity towards styrene oxide (SO) and benzyl glycidyl ether (BGE). The vEH-Am preferentially converted (S)-SO, leaving (R)-SO with the enantiomeric excess (ee) >99%. However, (R)-BGE was preferentially hydrolyzed by vEH-Am, resulting in (S)-BGE with >99% ee. To investigate the origin of regioselectivity, the interactions between vEH-Am and enantiomers of SO and BGE were analyzed by molecular docking simulation. In addition, it was observed that the yields of (R)-SO and (S)-BGE decreased with the increase of substrate concentrations. The yield of (R)-SO was significantly increased by adding 2% (v/v) Tween-20 or intermittent supplementation of the substrate. To our knowledge, vEH-Am displayed the highest enantioselectivity for the kinetic resolution of racemic BGE among the known EHs, suggesting promising applications of vEH-Am in the preparation of optically active BGE. [ABSTRACT FROM AUTHOR]

Acute liver injury (ALI) and acute kidney injury (AKI) are significantly affected by the antioxidant status. In the present study, the protective effect and mechanism of the collagen peptide Phe-Leu-Ala-Pro (FLAP) in mice with ALI and AKI induced by carbon tetrachloride (CCl 4 ) were examined. The results showed that FLAP effectively improved the liver mass index, the renal mass index, and the histopathological morphology. FLAP treatment significantly decreased the levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), urea nitrogen (BUN), and creatinine (CRE) but increased the activity of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px). The protein expression levels of nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), p -protein kinase B ( p -AKT), and p -phosphatidylinositol-3-kinase ( p -PI3K) in the liver and kidneys were significantly up-regulated after FLAP treatment. FLAP down-regulated the levels of interleukin-6 (IL-6), IL-1β, tumor necrosis factor-α (TNF-α), and nuclear factor-κ B (NF-κB) in liver and kidney tissues. Thus, FLAP may play a protective role in ALI and AKI by attenuating oxidative stress and inflammation mediated by the Nrf2/anti-response element (ARE) and PI3K/AKT/NF-κB pathways., Competing Interests: The authors declare no competing financial interest., (© 2022 The Authors. Published by American Chemical Society.)

Collagen peptide from Acaudina molpadioides (AMP) showed antioxidative activity in H 2 O 2 -induced RAW264.7 cells in our pervious study. In this study, it was observed that AMP could effectively improve the morphology and function of liver in CCl 4 -induced mice. After 200 mg/kg AMP treatment, the content of MDA in liver decreased by 62.3%, and the level of antioxidant enzymes (SOD, GSH-Px, and CAT) increased by more than 65%. Western blot results disclosed that AMP (200 mg/kg) upregulated the Nrf2 level by 73.8% and downregulated Keap1 by 41.0% in CCl 4 -induced mice liver. The levels of p-ERK, p-JNK, and p-p38 in 200 mg/kg AMP treatment groups decreased by 57.3%, 40.9%, and 40.6%, but the levels of p-PI3K and p-AKT increased by 162.6% and 60.3%, respectively. Furthermore, the trends of Nrf2, Keap1, p-ERK, p-JNK, p-p38, p-PI3K, and p-AKT levels in H 2 O 2 -induced RAW264.7 cells after AMP treatment were similar to the results in CCl 4 -induced mice liver. These findings provided evidence that AMP exerted antioxidant activity via Keap1/Nrf2-ARE, PI3K/AKT, and MAPKs pathways in vivo and in vitro. Therefore, the collagen peptide from A. molpadioides might represent a novel functional food to prevent acute liver injury via attenuation of oxidative stress., (© 2022 Institute of Food Technologists®.)

Collagen is a promising biomaterial used in the beauty and biomedical industries. In this study, the physicochemical characterization, antioxidant activities, and protective effects against H 2 O 2 -induced injury of collagen isolated from Acaudina molpadioides were investigated. The amino acid composition analysis showed that the collagen was rich in glycine (Gly), alanine (Ala), and glutamic acid (Glu), but poor in tyrosine (Tyr) and phenylalanine (Phe). Zeta potential analysis revealed that the isoelectric point (pI) of collagen from Acaudina molpadioides was about 4.25. It possessed moderate scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radicals in a dose-dependent manner. In addition, the collagen was able to effectively improve cell viability and morphology, inhibit the production of Malondialdehyde (MDA), and increase the activities of Superoxide Dismutase (SOD) and Glutathione Peroxidase (GSH-Px) in cultured RAW264.7 cells, resulting in a protective effect against H 2 O 2 -induced injury. Overall, the results showed that collagen extracted from A. molpadioides has promising prospects in the beauty and cosmetics industries.