The Dry Eye Zone

Rebecca's Blog


Study: Larch arabi-something and wound healing

Below is an interesting new study that popped up on Medline. Usually I don't get too excited about studies with words of ten syllables other than to take a mental note along the lines of "here's something that might lead to something that eventually ends up in the drug pipeline ten years hence" but this one caught my eye. Larch trees are a little off the beaten track even for dry eye treatment, where we come across everything from snake oil to iguana spit. Plus, anything that talks about "mucoadhesive" properties (i.e. helping lubricants stay on the eye longer) is something I want to know about.

If I knew anything about naturopathy or dietary supplements (I don't) I probably wouldn't have had to google this polysaccharide (I did). Here's a link to an article with more background that I found helpful.

Larch Arabinogalactan for Dry Eye Protection and Treatment of Corneal Lesions: Investigation in Rabbits.
Burgalassi S, Nicosia N, Monti D, Falcone G, Boldrini E, Chetoni P. J Ocul Pharmacol Ther. 2007 Nov 14.

Purpose: The aim of the present study was to investigate the corneal protective and healing properties of arabinogalactan (AG), a natural polysaccharide present in conifers of the genus Larix (Larch). AG was tested in comparison with other two polysaccharides possessing well-established properties in the treatment of dry eye: tamarind seed polysaccharide and hyaluronic acid. Methods: The AG formulation was subjected to the following investigations: rheologic measurements; evaluation of mucoadhesive properties by rheologic interaction with mucin; ferning test; and in vivo evaluation on rabbits, including treatment of an experimental dry eye; evaluation of the preocular retention; and evaluation of healing rate of experimental corneal wound. Results: AG dispersions showed a newtonian nonviscous behavior, eta = 1.6 mPa . s for 10% w/w solution; it possessed good mucoadhesive properties useful for retention on the eye surface. In fact, a prolonged time of residence in rabbit eyes was ascertained using fluorescein-labeled AG. Five percent (5.0%) w/w AG exerted a good protective effect against the appearance of corneal dry spots. It also reduced significantly the healing time of an experimental corneal lesion since 27 h after the first treatment. Conclusions: These findings suggest that AG may be a potential therapeutic product for dry eye protection and for the treatment of corneal wounds.