Characterization of Rabbit Corneas Subjected to Stromal Stiffening by the Açaí Extract (Euterpe oleracea).
In this study, we characterized rabbit corneas subjected to corneal cross-linking (CXL) with açaí extract compared with a riboflavin photo-stimulated procedure.



The corneas of the slaughterhouse rabbits were divided into three groups: control, consisting of untreated corneal samples; riboflavin/UVA, where corneas were treated with 0.1% riboflavin photo-stimulated at 365 nm as the standard protocol; and açaí, where the samples were subjected to 4% açaí extract for 0.5-2 h. After the CXL procedure, corneas of the three groups were characterized by analyzing their elastic modulus and thermal denaturation profile.



The elastic modulus at 3% strain showed an approximately threefold increase in the riboflavin/UVA group and 10.5 times in the corneas treated with 4% açaí extract for 2 h, compared with the control group (p < 0.01). The denaturation temperature values of the two groups of crosslinked corneas increased significantly (p < 0.05) and were more pronounced in the açaí group.



The açaí extract was effective in promoting CXL in rabbit corneas as characterized by the different techniques.
a Departamento de Informática em Saúde , Escola Paulista de Medicina, Universidade Federal de São Paulo , São Paulo , Brazil.|b Departamento de Oftalmologia e Ciências Visuais , Escola Paulista de Medicina, Universidade Federal de São Paulo , São Paulo , Brazil.
Patrícia A
PA
Bersanetti
b Departamento de Oftalmologia e Ciências Visuais , Escola Paulista de Medicina, Universidade Federal de São Paulo , São Paulo , Brazil.
Tatiane L N
TL
Bueno
c Departamento de Engenharia Química , Centro Universitário da FEI , São Bernardo do Campo , Brazil.
Andreia de A
AA
Morandim-Giannetti
a Departamento de Informática em Saúde , Escola Paulista de Medicina, Universidade Federal de São Paulo , São Paulo , Brazil.
Regina F
RF
Nogueira
d Departamento de Química Fundamental , Instituto de Química, Universidade de São Paulo , Brazil.
Jivaldo R
JR
Matos
b Departamento de Oftalmologia e Ciências Visuais , Escola Paulista de Medicina, Universidade Federal de São Paulo , São Paulo , Brazil.
Paulo
P
Schor
D000818:Animals; D003094:Collagen / Q000378:metabolism*; D003315:Cornea / Q000187:drug effects / Q000378:metabolism; D003319:Corneal Stroma / Q000378:metabolism*; D003432:Cross-Linking Reagents; D055119:Elastic Modulus / Q000187:drug effects; D065748:Euterpe / Q000737:chemistry*; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*; D011817:Rabbits; D012256:Riboflavin / Q000494:pharmacology; D014466:Ultraviolet Rays
D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D010936:Plant Extracts; D003094:Collagen; D012256:Riboflavin
Açaí extract; corneal crosslinking; differential scanning calorimetry; elastic modulus; keratoconus; riboflavin