Preservation of retinal function by paeoniflorin following retinal light injury

Abstract

Purpose : Age-related macular degeneration (AMD) is a leading cause of blindness in the United States and other developed nations. Current treatment modalities targeting AMD are beneficial to only a small proportion of patients with the end-stage form and do not necessarily prevent progression of the disease. Paeoniflorin (PF) is one of the main active components of Paeonia Radix, a traditional Chinese herbal medicine derived from the root of Paeonia lactiflora Pallas. Paeoniflorin possesses both anti-inflammatory and anti-oxidant properties and has been implicated as a potential therapy in other degenerative pathologies such as Alzheimer’s disease. We hypothesize that paeoniflorin will have protective effects against retinal degeneration in a mouse model of retinal light injury.

Methods : BALB/c albino mice were assigned to one of two groups: vehicle-treated (control) or paeoniflorin-treated retinal light injury mice. Vehicle (PBS) or paeoniflorin (20 mg/kg in PBS) was injected intraperitoneally, and mice were then exposed to 10,000 lux cool white fluorescent light for 2 hours to induce light injury. Both groups had treatment administered once daily for 4 additional days following light injury for a total of 5 treatments. Scotopic electroretinography (ERG) was recorded before light injury and 4 days following light injury.

Results : Before treatment, scotopic ERG a- and b-wave amplitudes were an average of 542 ± 31 μV and 1005 ± 61 μV, respectively, in the control group and 452 ± 109 μV and 867 ± 147 μV, respectively, in the paeoniflorin treatment group. Following retinal light injury, ERG a-wave amplitudes were 132 ± 17 μV in the control group and 250 ± 59 μV in the paeoniflorin treatment group (p < 0.005). Following retinal light injury, ERG b-wave amplitudes were 304 ± 42 μV in the control group and 518 ± 138 μV in the paeoniflorin treatment group (p < 0.005). There was significantly greater preservation of ERG a- and b-wave amplitudes in the paeoniflorin treatment group, suggesting that paeoniflorin is able to attenuate the degree of degenerative loss of retinal function in a retinal light injury model.

Conclusions : Paeoniflorin treatment of mice had a significant impact on the preservation of ERG a-and b-wave amplitudes following retinal light injury when compared to a control group. Our preliminary findings suggest that paeoniforin may have therapeutic value in the management of retinal degenerative conditions.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.