Aloe vera: an in vitro study of effects on corneal wound closure and collagenase activity
Authors
Elizabeth M. Curto,Amber Labelle and Heather L. Chandler
Institution
College of Optometry, The Ohio State University, Columbus, OH, USA; and Veterinary Clinical Medicine, University of Illinois Urbana-Champaign, Urbana, IL, USA
Country
United States
Year
2014
Journal
Veterinary Ophthalmology
Abstract
Purpose To evaluate the in vitro effects of an aloe vera solution on (i) the viability and
wound healing response of corneal cells and (ii) the ability to alter collagenase and
gelatinase activities.
Methods Primary cultures of corneal epithelial cells and fibroblasts were prepared from
grossly normal enucleated canine globes and treated with an aloe solution (doses ranging
from 0.0–2 mg/mL). Cellular viability was evaluated using a colorimetric assay. A
corneal wound healing model was used to quantify cellular ingrowth across a defect
made on the confluent surface. Anticollagenase and antigelatinase activities were evaluated
by incubating a bacterial collagenase/gelatinase with aloe solution (doses ranging
from 0.0–500 lg/mL) and comparing outcome measures to a general metalloproteinase
inhibitor, 1, 10-phenanthroline, and canine serum (doses ranging from 0.0–100%).
Results None of the concentrations of aloe solution tested significantly affected the
viability of corneal epithelial cells or fibroblasts. Concentrations ≤175 lg/mL slightly
accelerated corneal epithelial cell wound closure; this change was not significant.
Concentrations ≥175 lg/mL significantly (P ≤ 0.001) slowed the rate of corneal fibroblast
wound closure, while aloe concentrations <175 lg/mL did not significantly alter
fibroblast wound closure. Aloe solution did not alter the ability for collagenase to
degrade gelatin or collagen Type I but increased the ability for collagenase to degrade
Type IV collagen.
Conclusions Although additional experiments are required, lower concentrations of aloe
solution may be beneficial in healing of superficial corneal wounds to help decrease
fibrosis and speed epithelialization. An increase in collagenase activity with aloe vera
warrants further testing before considering in vivo studies.