Interaction between curcumin and a peptide and their protective effects against hepatic steatosis in mice

Soy Peptide Supplementation Mitigates Undernutrition through Reprogramming Hepatic Metabolism in a Novel Undernourished Non-Human Primate Model

In spite of recent advances in the field of undernutrition, current dietary therapy relying on the supply of high protein high calorie formulas is still plagued with transient recovery of impaired organs resulting in significant relapse of cases. This is partly attributed to the inadequacy of current research models in recapitulating clinical undernutrition for mechanistic exploration. Using 1636 Macaca fascicularis monkeys, a human-relevant criterion for determining undernutrition weight-for-age z-score (WAZ), with a cutoff point of ≤ -1.83 is established as the benchmark for identifying undernourished nonhuman primates (U-NHPs). In U-NHPs, pathological anomalies in multi-organs are revealed. In particular, severe dysregulation of hepatic lipid metabolism characterized by impaired fatty acid oxidation due to mitochondria dysfunction, but unlikely peroxisome disorder, is identified as the anchor metabolic aberration in U-NHPs. Mitochondria dysfunction is typified by reduced mito-number, accumulated long-chain fatty acids, and disruption of OXPHOS complexes. Soy peptide-treated U-NHPs increase in WAZ scores, in addition to attenuated mitochondria dysfunction and restored OXPHOS complex levels. Herein, innovative criteria for identifying U-NHPs are developed, and unknown molecular mechanisms of undernutrition are revealed hitherto, and it is further proved that soypeptide supplementation reprogramed mitochondrial function to re-establish lipid metabolism balance and mitigated undernutrition.

Antioxidants ameliorate oxidative stress in alcoholic liver injury by modulating lipid metabolism and phospholipid homeostasis

Alcoholic liver disease (ALD) is a significant risk factor in the global disease burden. The antioxidants vitamin C (Vc) and N-acetyl cysteine (NAC) have shown hepatoprotective effects in preventing and treating ALD. However, the correlation between the improved effect of antioxidants and lipid metabolism is still unclear. In this study, AML12 cells and C57BL/6 mice stimulated with alcohol were used to investigate the protective effects and potential mechanisms of two antioxidants (Vc and NAC) on alcoholic liver injury. Results showed that Vc and NAC attenuated intracellular lipid accumulation and oxidative damage induced by excessive alcohol exposure in hepatic AML12 cells. The in vivo results indicated that antioxidants ameliorated alcohol-induced changes in histopathology, reducing the levels of alcohol metabolizing factors and aspartate aminotransferase (AST), alanine aminotransferase (ALT), triglyceride (TG), and total cholesterol (TC) contents, which demonstrated that antioxidants effectively mitigated liver injury in ALD mice. Further studies showed that antioxidants reversed the disruption of fatty acid (FA) synthesis and lipid transport induced by alcohol exposure, and restored phospholipid levels. Especially, Vc and NAC increased the endogenous antioxidant plasmenyl phosphatidylethanolamine (PlsEtn). Additionally, antioxidants ameliorated the alcohol-impaired mitochondrial function and inhibited excessive oxidative stress. In conclusion, antioxidants can regulate lipid metabolism and phospholipid homeostasis, which in turn inhibit oxidative stress and thereby exert protective effects against ALD.

Intestinal absorptivity-increasing effects of sodium N-[8-(2-hydroxybenzoyl)amino]-caprylate on food-derived bioactive peptide

Delivering bioactive peptides orally is hampered by poor absorption across the gastrointestinal barrier. Using the walnut-derived peptide PW5, PPKNW, we explored whether coformulation of peptides with absorption enhancer sodium N-[8-(2-hydroxybenzoyl)aminocaprylate] (SNAC) could improve the intestinal absorption of orally-administered bioactive peptides. Herein, the application of SNAC enhanced the absorption efficiency of PW5 in a non-everted gut sac model. Particle size distribution (1 027.8 ± 6.74 nm) and zeta potential (-2.89 ± 0.07 mV) of the PW5-SNAC complex were significantly greater than that of individual PW5 and SNAC. Scanning electron microscopy revealed that SNAC application could aggravate the surface roughness and reduce the compact structure of PW5. It further showed that PW5 and SNAC binds through an endothermic process underpinned by hydrogen bond and van der Waals forces and that SNAC could bound primarily to the internal calyx of PW5. These findings are helpful for the effective delivery of bioactive peptides.