Assessing efficacy of combined riboflavin and UV-A light (365 nm) treatment of Acanthamoeba trophozoites.

Abstract

PURPOSE:

To assess the Acanthamoeba trophozoite viability in vitro and treatment of Acanthamoeba keratitis in a hamster model using ultraviolet light A (UV-A) and riboflavin (B2).

METHODS:

A sample of Acanthamoeba sp. cultured was transferred to a 96-well plate and exposed to B2 and the UV-A light (365 nm wavelength) at a power density of 3 mW/cm(2), 8 mm spot diameter, for 30 minutes. The exposure was done in triplicate. Control groups were prepared in triplicate as well: blank control, UV-A only, riboflavin only, and dead control. Cell viability assessment was done using the trypan blue dye exclusion method. Acanthamoeba keratitis was induced in Chinese hamsters; who were randomly assigned to one of the animal groups: UV-A + B2, propamidine isethionate (Brolene; Sanofi-Aventis, Ellerslie, Auckland, Australia), UV-A + B2 + propamidine isethionate (Brolene), only UV-A, only B2, and blank. Throughout the 14 days after treatment the animals were examined clinically. Histology and clinical scores of all groups were compared.

RESULTS:

The in vitro study showed no difference between the treatment group UV-A + B2 and the control groups. In the hamster keratitis model a significant improvement of clinical score was observed for the groups propamidine isethionate (Brolene) and UV-A + B2 + propamidine isethionate (Brolene) (P = 0.0067). Also a significant worsening of clinical score was observed in the other groups: UV-A + B2 group (P = 0.0084), only UV-A (P = 0.0078), B2 only (P = 0.0084), and blank (P = 0.0082). No difference was observed between propamidine isethionate (Brolene) and UV-A + B2 + propamidine isethionate (Brolene).

CONCLUSIONS:

The adjunctive use of UV-A and B2 therapy did not demonstrate antitrophozoite activity; in vivo UV-A and B2 did not demonstrate efficacy in this model.

• Authors: Renata T Kashiwabuchi, Fabio R S Carvalho, Yasin A Khan, Denise de Freitas, Annette S Foronda, Flavio E Hirai, Mauro S Campos, Peter J McDonnell
• Journal: Investigative ophthalmology & visual science (Invest Ophthalmol Vis Sci) Vol. 52 Issue 13 Pg. 9333-8 (Dec 09 2011) ISSN: 1552-5783 [Electronic] United States
• PMID: 22058341 (Publication Type: Journal Article)

Chemical References

• Vitamin B Complex
• Riboflavin

Topics

• Acanthamoeba Keratitis (pathology, therapy)
• Animals
• Cornea (drug effects, parasitology, radiation effects)
• Cricetinae
• Disease Models, Animal
• Female
• Follow-Up Studies
• Humans
• Middle Aged
• Riboflavin (therapeutic use)
• Treatment Outcome
• Ultraviolet Therapy (methods)
• Vitamin B Complex (therapeutic use)