The mediation of the AHR/IL-22/STAT3/IL-6 axis by soft-shelled turtle (Pelodiscus sinensis) peptide and Chinese pond turtle (Chinemys reevesii) peptide contributed to their amelioration effects on intestinal mucosal immunity in immunosuppressed mice.

This study investigated the immunomodulatory effects of soft-shelled turtle (Pelodiscus sinensis) peptide (TP) and Chinese pond turtle (Chinemys reevesii) peptide (TMP) on the intestinal mucosal immune system (IMIS). The results demonstrated that TP and TMP improved holistic immunity by restoring the vital immune organ atrophy and proliferation capacity of spleen immune cells. Moreover, TP and TMP significantly increased the serum content of IgA and cytokines that are responsible for immune cell activation and antigen clearance. TP and TMP promoted intestinal B cell activation, class switching recombination, and antibody secreting processes in a T cell-independent manner to increase the SIgA content. Furthermore, TP and TMP enhanced the intestinal barrier by increasing the protein expression of tight junctions (TJs) and adhesion junctions (AJs) and ameliorating the intestinal morphology. Mechanistically, TP and TMP activated the AHR/IL-22/STAT3/IL-6 axis to enhance the IgA response and improve the intestinal barrier, indicating their potential in intestinal health modulation.

Soft-Shelled Turtle Peptides Extend Lifespan and Healthspan in Drosophila.

In traditional Chinese medicine, soft-shelled turtle protein and peptides serve as a nutraceutical for prolonging the lifespan. However, their effects on anti-aging have not been clarified scientifically in vivo. This study aimed to determine whether soft-shelled turtle peptides (STP) could promote the lifespan and healthspan in Drosophila melanogaster and the underlying molecular mechanisms. Herein, STP supplementation prolonged the mean lifespan by 20.23% and 9.04% in males and females, respectively, delaying the aging accompanied by climbing ability decline, enhanced gut barrier integrity, and improved anti-oxidation, starvation, and heat stress abilities, while it did not change the daily food intake. Mechanistically, STP enhanced autophagy and decreased oxidative stress by downregulating the target of rapamycin (TOR) signaling pathway. In addition, 95.18% of peptides from the identified sequences in STP could exert potential inhibitory effects on TOR through hydrogen bonds, van der Walls, hydrophobic interactions, and electrostatic interactions. The current study could provide a theoretical basis for the full exploitation of soft-shelled turtle aging prevention.

Evaluating dynamic effects of dietary glycerol monolaurate on the productive performance and flesh quality of large yellow croaker (Larimichthys crocea).

The effects of GML (Glycerol monolaurate) supplementation with two level (0.5 and 1.0 g kg-1) on the productive performance and flesh quality of large yellow croaker (360 per group) were investigated during feeding (23,50-days) and fasting stage (23,70-days). The GML supplementation significantly increased body weight after 23-days and crude protein, inosinic acid, and yellowness after 50-days. Moreover, it increased hardness, springiness, and chewiness by increasing the collagen content, myofiber density, and decreasing myofiber diameter. The high GML supplementation increased the total free amino acids, delicate amino acids, monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (n-3 PUFA), and EPA + DHA, whereas it decreased the content of saturated fatty acids/unsaturated fatty acids (SFA/UFA). During fasting, better body shape and color were shown were shown at high GML supplementation. Conclusively, high dose GML supplementation exerted promising effects on the productive performance and flesh quality of large yellow croaker.