Lee JS, et al. Nutr Res Pract. 2024 Jun;18(3):357-371. https://doi.org/10.4162/nrp.2024.18.3.357

Aging is often accompanied by chronic oxidative stress, contributing to the progression of metabolic disorders. A previous study reported that supplementation with collagen tripeptide (CTP) inhibits fatty liver and lipid hypertrophy, but the mechanism is unclear. This study examined the effects of 12-week CTP supplementation on oxidative stress, insulin resistance, and adenosine monophosphate-activated protein kinase (AMPK) α activation, key factors in metabolic disorders in aged mice. Thirty-eight male C57BL/6J mice (58 weeks old) were assigned to 4 groups: aging control, 0.03% Gly-Pro-Hyp, 0.9% CTP, and 0.9% granulated collagen tripeptide (gCTP) supplementation. A group of young mice (YC, n = 8) served as the positive control. The results showed that CTP and gCTP enhance antioxidant capacity by reducing thiobarbituric acid reactive substances and H₂O₂ and improving the antioxidant enzyme activities, including superoxide dismutase and glutathione peroxidase. CTP also improved insulin sensitivity by increasing the expression of insulin receptors and glucose transporters in the liver and white adipose tissue. Furthermore, CTP and gCTP improved energy metabolism and mitochondrial function via AMPKα activation. CTP supplementation is a promising intervention to mitigate comorbidities in older adults, such as obesity and fatty liver disease. CTP and gCTP supplementation may serve as functional ingredients to improve energy metabolism and mitochondrial function. Their potential to reduce oxidative stress, improve insulin resistance, and enhance AMPKα expression supports their use in managing obesity and fatty liver disease, particularly in older adults.

Background/aim: Collagen-derived peptides have shown potential in promoting hair growth, yet their effects on catagen-inducing factors remain unexplored. In this study, the hair growth-promoting effects and molecular mechanisms of Collagen-Tripep20 (CTP), a collagen tripeptide preparation containing 3.2% Gly-Pro-Hyp (GPH), were explored, with a specific focus on fibroblast growth factor 5 (FGF-5) regulation. Materials and methods: Female C3H/HeJ mice were randomly assigned to four groups (n = 10/group): control, CTP-LOW (400 mg/ kg/day), CTP-HIGH (800 mg/kg/day), and GPH (25.6 mg/kg/day). Following dorsal depilation, test substances were administered dailyvia oral gavage for 7 weeks. Hair regrowth was assessed by visual scoring, histological analysis, and quantitative RT-PCR of dorsal skin tissues. Results: CTP-HIGH significantly accelerated telogen-to-anagen transition, with elevated hair growth scores at weeks 5 and 6 (p < 0.01 and p < 0.05, respectively). Histological analysis confirmed a significant increase in hair follicle length in the CTP-HIGH group (p < 0.001). Both CTP and GPH upregulated the mRNA expression of anagen-promoting markers, including VEGF and FGF-7. Notably, GPH significantly downregulated FGF-5 mRNA to 0.86 ± 0.11-fold relative to the control (p < 0.05), whereas CTP-HIGH showed asimilar but nonsignificant trend (0.87 ± 0.07-fold). Conclusion: CTP promotes anagen induction through upregulation of growth-related factors, while its bioactive component GPH additionally functions as a transcriptional suppressor of FGF-5, providing a dual-mechanistic rationale for collagen-derived tripeptides in managing hair cycle dynamics.