Dosage dependence of the effect of Ginkgo biloba on the rat retinal ganglion cell survival after optic nerve crush

Abstract

Purpose To investigate the dosage dependence of the Ginkgo biloba effect on retinal ganglion cell survival in the rat optic nerve crush model. Methods The study included 56 SpragueDawley rats, the right optic nerve of which was crushed in a standardized manner. Two hours after the crush and once daily during the follow-up, the animals received intragastral applications of saline (saline group; n ¼ 13), or of a G. biloba extract of 0.25% concentration (n ¼ 14; low-dosage group), 1% concentration (n ¼ 15; medium-dosage group), or 4% concentration (n ¼ 14; high-dosage group). At 23 days after the optic nerve crush, the retinal ganglion cells were retrogradely labelled by injecting 3% fluorogold into the superior colliculi of the brain. At 4 weeks after baseline, the animals were killed. Retinal flat mount photographs were assessed for number and density of the retinal ganglion cells. Results The mean survival rate defined as the ratio of retinal ganglion cell density in the right eye with optic nerve crash divided by the retinal ganglion cell density in left eye without optic nerve intervention increased significantly (Po0.001) from 58.4 ± 9.0% in the saline group to 68.5 ± 5.7% in the low-dosage group, to 73.7 ± 6.4% in the medium-dosage group, and to 74.2 ± 6.8% in the high-dosage group. Conclusions Intragastral applications of a G. biloba extract applied after an experimental and standardized optic nerve crush in rats were associated with a higher survival rate of retinal ganglion cells in a dosage-dependent manner.

The effect of ginkgo biloba on the rat retinal ganglion cell survival in the optic nerve crush model

“…When compared to their contralateral saline eyes with normal intraocular pressure at 5 months after the induction of an intraocular elevation, the retinal ganglion cell loss in the eyes with chronic, moderately elevated intraocular pressure was 4.6 ± 4.5% in the rates receiving ginkgo biloba compared to 29.8 ± 1.5% in the animals without gingko biloba. The present study is also in agreement with a similar investigation by the same group of researchers, in which the daily intragastral application of ginkgo biloba after an optic nerve crush model was associated with a higher survival rate of retinal ganglion cells (Ma et al. 2008).…”

Natural Products: Evidence for Neuroprotection to Be Exploited in Glaucoma

“…In the episcleral vein cauterization model, treatment with EGb 761 for 5 months induced a significant reduction of RGC loss [ 213 ]. Similar results were observed in a model of ON crush following four weeks of treatment with the extract [ 214 , 215 , 216 ].…”

Neuroprotective effect of intravitreal cell‐based glucagon‐like peptide‐1 production in the optic nerve crush model

“…After the tracer injections, the wound was sutured, an antibiotic ointment applied, and the animal was allowed to recover. The principal investigator (KM) had a practical experience of the study procedures obtained in more than 50 animals prior to the start of the present investigation (Ma et al. 2009a,b, 2010).…”