Efficacy of a 2-month dietary supplementation with polyunsaturated fatty acids in dry eye induced by scopolamine in a rat model.
BACKGROUND
This study was conducted to evaluate the efficacy of dietary n-6 and n-3 polyunsaturated fatty acids (PUFAs) in dry eye in a rat model.


METHODS
Female Lewis rats were fed with diets containing (1) gamma-linolenic acid (GLA), (2) eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA), or (3) GLA + EPA + DHA, for 2 months before the induction of dry eye using a continuous delivery of scopolamine and during scopolamine treatment. Two, 10 and 28 days after dry-eye induction, clinical signs of corneal dryness were evaluated in vivo using fluorescein staining. MHC II expression and mucin rMuc5AC production in the conjunctival epithelium were evaluated by immunostaining. Lipids and prostaglandins (PGs) E(1) and E(2) were analysed from the exorbital lacrimal gland (LG).


RESULTS
Dietary PUFAs minimised the occurrence of corneal keratitis 28 days after induction of dry eye. The decrease in mucin production observed on the conjunctival epithelium was partially prevented by EPA + DHA supplementation after 2 days of scopolamine treatment, as well as by GLA and GLA + EPA + DHA diets after 10 days of treatment. The overexpression of MHC II in the conjunctival epithelium caused by dry eye induction was significantly reduced only with the GLA + EPA + DHA diet after 28 days of treatment. Dietary PUFAs were incorporated into phospholipids of the exorbital LG. Induction of dry eye was associated with a significant increase in PGE(1) and PGE(2) levels in the exorbital LG, which was inhibited by dietary EPA + DHA at 10 days (for PGE(2)) and 28 days (for PGE(1)).


CONCLUSIONS
Dietary GLA, EPA and DHA significantly interfered with lipid homeostasis in the exorbital LG and partially prevented the course of dry eye. In particular, our results demonstrate the efficacy of the combination of n-6 and n-3 PUFAs.
INRA, UMR1129 FLAVIC, Eye and Nutrition Research Group, Dijon, 21000, France.
Sabrina
S
Viau
Marie-Annick
MA
Maire
Bruno
B
Pasquis
Stéphane
S
Grégoire
Niyazi
N
Acar
Alain M
AM
Bron
Lionel
L
Bretillon
Catherine P
CP
Creuzot-Garcher
Corinne
C
Joffre
D000818:Animals; D003228:Conjunctiva / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D019587:Dietary Supplements; D004195:Disease Models, Animal; D004281:Docosahexaenoic Acids / Q000008:administration & dosage; D015352:Dry Eye Syndromes / Q000139:chemically induced / Q000178:diet therapy* / Q000378:metabolism / Q000473:pathology; D015118:Eicosapentaenoic Acid; D004848:Epithelium / Q000378:metabolism; D005231:Fatty Acids, Unsaturated / Q000008:administration & dosage; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D007124:Immunoenzyme Techniques; D007765:Lacrimal Apparatus / Q000378:metabolism / Q000473:pathology; D050356:Lipid Metabolism; D055271:Mucin 5AC / Q000378:metabolism; D051381:Rats; D011917:Rats, Inbred Lew; D012601:Scopolamine / Q000633:toxicity; D016896:Treatment Outcome; D017965:gamma-Linolenic Acid / Q000008:administration & dosage
D004042:Dietary Fats, Unsaturated; D005231:Fatty Acids, Unsaturated; D000949:Histocompatibility Antigens Class II; D055271:Mucin 5AC; D004281:Docosahexaenoic Acids; D017965:gamma-Linolenic Acid; D015118:Eicosapentaenoic Acid; D012601:Scopolamine