Journal Club 2015.10.02.

Oral supplementation with fish oil reduces dryness and pruritus in the acetone-induced dry skin rat model

1-s2.0-S0923181115300207-main

Raquel C.S. Barcelosa,b,c,d,f, Cristina de Mello-Sampayob,c,f,*, Caren T.D. Antoniazzia, Hecson J. Segata, Henrique Silvad, Juliana C. Veite, Jaqueline Piccoloe,
Tatiana Emanuellia,e, Marilise E. Bürgera, Beatriz Silva- Limab,c, Luis M. Rodriguesb,d
a Universidade Federal de Santa Maria (UFSM), Programa de Pós-Graduação em Farmacologia, Santa Maria, RS, Brazil
b Pharmacological Sciences Department, Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
c Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
d CBIOS, Research Center for Bioscience and Health Technologies, Universidade Lusófona, Lisboa, Portugal
e Departamento de Tecnologia dos Alimentos, Programa de Pós-Graduação em Ciência Tecnologia dos Alimentos, Universidade Federal de Santa Maria, Av. Roraima, 1000, 97105-900 Santa Maria, RS, Brazil
f Both authors have contributed equally to this work.

Background: Pruritus and discomfort are often present in patients with xerosis and atopic dermatitis. Several studies suggest an important role of diet in skin pathophysiology.
Objective: This study evaluated the effect of dietary fatty acids in the skin physiology via an itch-related animal model with and without supplementation with fish oil (FO), a source of polyunsaturated fatty acids (PUFA), especially omega 3 (n-3).
Methods: Male Wistar rats were divided into two groups—non-supplemented (control) and supplemented with FO (3g/kg/day) by gavage for 90 days. Every 30 days, scratching and skin parameters (transepidermal water loss (TEWL), hydration, and local blood flow) were evaluated before and after dorsal skin exposure to acetone to induce the itch-related dry skin. At the end of the study, animals were sacrificed, and skin samples collected for fatty acids composition analysis by GC–FID. Results: FO supplementation reduced the TEWL and increased the skin hydration, with significant changes from day 60 on, while skin microcirculation registered no changes. It also alleviated the acetone induced skin barrier alteration, revealed by a faster resolution of TEWL and hydration, and elimination of itch-related scratching induced by dry skin. These changes were associated with the shift in the skin fatty acids incorporation pattern (richer in n-3 with n-6/n-3 < 5) resulting from the FO supplementation. Conclusion: Skin barrier dynamics seem to be influenced by FO n-3 PUFA, with suppressive effects on the scratching behaviour induced by dry skin. Hence, long-term supplementation with n-3 PUFA rich nutrients might reinforce and restore cutaneous integrity and function.
ã 2015 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.