Hepatic retinaldehyde dehydrogenases are modulated by tocopherol supplementation in mice with hepatic steatosis.

OBJECTIVES: An altered retinol metabolism might play a role in the development of nonalcoholic fatty liver disease (NAFLD). Tocopherols (TF) modulate metabolic pathways and have been proposed as a complementary treatment of obesity-induced metabolic alterations. Moreover, there is evidence suggesting that TF may modulate retinol metabolism. The aim of this study was to evaluate whether the dietary supplementation of α- and γ-TF modulates the expression of hepatic retinaldehyde dehydrogenases, RALDH1, RALDH2, and RALDH3 (involved in retinol metabolism) and, lipogenic factors sterol regulatory element binding protein-1c (SREBP-1c) and cluster differentiation 36 (CD36) in an animal model of diet-induced NAFLD. METHODS: Male C57BL/6J mice were divided into four groups: a control diet (CD) group (10% fat, 20% protein, 70% carbohydrates); a CD + TF group (α-tocopherol: 0.7 mg·kg·d-1, γ-tocopherol: 3.5 mg·kg·d-1); a high-fat diet (HFD) group (60% fat, 20% protein, 20% carbohydrates); and a HFD + TF group (0.01 mL·g body weight·d-1), for 12 wk. General parameters (body-adipose tissue weight, glucose-triacylglyceride serum levels), liver steatosis (histology, liver triacylglycerides content), and hepatic RALDH1, RALDH2, RALDH3, SREBP-1c and CD36 (qPCR, quantitative polymerase chain reaction; IHQ, immunohistochemistry) were measured. RESULTS: TF supplementation in HFD-fed mice decreased the presence of lipid vesicles (90%) and total lipid content (75%) and downregulated the expression of RALDH1, RALDH3, SREBP-1c, and CD36. CONCLUSIONS: The present study demonstrated that α- and γ-TF (1:5 ratio) might play a role in modulating retinol metabolism in the prevention of NAFLD induced by a HFD.

Evaluation of cutaneous rejuvenation associated with the use of ortho-silicic acid stabilized by hydrolyzed marine collagen.

BACKGROUND: Organic silicon plays an important role in dermal structure by promoting neocollagenesis. Thus, the supplementation of silicon in a highly bioavailable form can be used for skin rejuvenation. AIMS: This study aimed to evaluate skin changes associated with the use of ortho-silicic acid stabilized by hydrolyzed collagen. PATIENTS/METHODS: Patients were randomized to receive 600 mg of ortho-silicic acid stabilized by hydrolyzed collagen (group 1, n = 11) or placebo (group 2, n = 11) to be taken 15 minutes before breakfast for 90 days. Clinical, photographical, and patients' subjective evaluations were conducted. RESULTS: A total of 22 patients were included. Clinical evaluations demonstrated changes in skin texture, firmness, and hydration statistically superior in group 1. Brightness, firmness, and overall appearance showed trends for a difference favoring group 1 according to patients' subjective evaluations. Objective images showed no statistical differences. No side effects, hypersensitivity, or systemic symptoms were observed in group 1. Treatment satisfaction in group 1 reached 80%. CONCLUSIONS: Ortho-silicic acid stabilized by hydrolyzed collagen in a daily dose of 600 mg showed positive results in skin rejuvenation according to clinical evaluation in firmness, hydration, and skin texture. Further studies with larger and representative samples should be conducted to confirm our results.