PMC

Digital images of facial skin ultrasound examinations (patient number 23, e.g.), made 2 months before the beginning of the trial (a), at the day of the trial beginning (b), and immediately after the trial cessation (c).

Systemic oxidative stress markers: plasma levels of nitrites/nitrates (NO₂ + NO₃) (a), of malonyl dialdehyde (MDA) (b), and of Cu,Zn-superoxide dismutase 3 (Cu,Zn-SOD3) (c) in the study group of patients (n = 41), before and after food supplement administration period. Values are represented as mean (□), standard error of the mean (upper and lower limits of the box), and 1.96 × standard error (upper and lower whiskers). Intergroup significant differences (p) are indicated in the relative panels. NO₂ + NO₃: nitrites + nitrates; MDA: malonyl dialdehyde. Reference normality range: plasma NO₂ + NO₃ (70.3–221.0 μM); plasma MDA (1.0–2.2 μM); plasma Cu,Zn-SOD3 (5.0–20.1 U/mL).

Glutathione cycle parameters: erythrocyte levels of total glutathione (reduced and oxidized forms, GSH + GSSG) (a) and erythrocyte enzymatic activities of glutathione-S-transferase (b) and of glutathione peroxidase (c) in the study group of patients (n = 41), before and after food supplement administration period. Values are represented as mean (□), standard error of the mean (upper and lower limits of the box), and 1.96 × standard error (upper and lower whiskers). GSH: reduced glutathione; GSSG: oxidized glutathione; RBC: red blood cells; Hb: haemoglobin; GST: glutathione S-transferase; GPx: glutathione peroxidase. Reference normality range: RBC total glutathione (0.5–1.6 mg/g Hb); RBC GST activity (0.2–0.7 U/mg Hb); RBC GPx activity (18.0–54.0 U/g Hb).

Metabolic parameters related to collagen and ATP synthesis: levels of plasma hydroxyproline (a) and of the lipophilic antioxidant total coenzyme Q₁₀ (reduced and oxidized forms, CoQ₁₀H₂ + CoQ₁₀) (b) and erythrocyte ATP (c) in the study group of patients (n = 41), before and after food supplement administration period. Values are represented as mean (□), standard error of the mean (upper and lower limits of the box), and 1.96 × standard error (upper and lower whiskers). Intergroup significant differences (p) are indicated in the relative panels. CoQ₁₀H₂: reduced coenzyme Q₁₀; CoQ₁₀: oxidized coenzyme Q₁₀; ATP: adenosine triphosphate; RBC: red blood cells. Reference normality range: total coenzyme Q₁₀ (0.4–1.6 mg/L); ATP (1.0–4.0 mM).

Scheme of the hypothesised redox-dependent mechanisms of CELERGEN physiological effects. Marine collagen peptides (MCPs) easily penetrate gastrointestinal wall (GI, three arrows) and through blood circulation are mainly deposited in the skin. Antioxidant component of the nutraceutical is partly metabolised in GI thus possessing low bioavailability (one arrow); however, skin-targeting antioxidants and their metabolites reach different skin layers. While in the circulation, MCPs stimulate blood phagocytes (granulocytes and monocytes) and endotheliocytes (E) to produce reactive oxygen species (ROS) and reactive nitrogen species (RNS) by activating Toll-like receptors 4 (TLR4). Hydroxyproline (HYP) and prolyl-hydroxyproline (Pro-HYP) dipeptides as major components of MCPs are metabolised by corresponding oxidases and hydroxyl radicals are formed as by-products. Antioxidants prevent systemic oxidative stress blocking GSH oxidation, GPx, GST, and SOD3 activation. In the skin, collagen synthesis and deposition as well as elasticity are increased while (hypothetically) low levels of oxidised forms of skin lipids such as unsaturated fatty acids (PUFA-ox), squalene (Sq-ox), malonyl dialdehyde (MDA), and 4-hydroxy-2-nonenal (4-HNE) may facilitate cell signalling for ATP synthesis and sebum production.