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Combining neuroprotectants in a model of retinal degeneration: no additive benefit.

Di Marco F, Di Paolo M, Romeo S, Colecchi L, Fiorani L, Spana S, Stone J, Bisti S - PLoS ONE (2014)

Bottom Line: Results confirmed the neuroprotective potential of each used separately, but gave no evidence that their effects are additive.Detailed analysis suggests that there is actually a negative interaction between PBM and saffron when given simultaneously, with a consequent reduction of the neuroprotection.Specific testing will be required to understand the mechanisms involved and to establish whether there is clinical potential in combining neuroprotectants, to improve the quality of life of people affected by retinal pathology, such as age-related macular degeneration, the major cause of blindness and visual impairment in older adults.

View Article: PubMed Central - PubMed

Affiliation: Department of Biotechnology and Applied Clinical Science, University of L'Aquila, L'Aquila, Italy.

ABSTRACT
The central nervous system undergoing degeneration can be stabilized, and in some models can be restored to function, by neuroprotective treatments. Photobiomodulation (PBM) and dietary saffron are distinctive as neuroprotectants in that they upregulate protective mechanisms, without causing measurable tissue damage. This study reports a first attempt to combine the actions of PBM and saffron. Our working hypothesis was that the actions of PBM and saffron in protecting retinal photoreceptors, in a rat light damage model, would be additive. Results confirmed the neuroprotective potential of each used separately, but gave no evidence that their effects are additive. Detailed analysis suggests that there is actually a negative interaction between PBM and saffron when given simultaneously, with a consequent reduction of the neuroprotection. Specific testing will be required to understand the mechanisms involved and to establish whether there is clinical potential in combining neuroprotectants, to improve the quality of life of people affected by retinal pathology, such as age-related macular degeneration, the major cause of blindness and visual impairment in older adults.

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Impact of single and combined neuroprotectants on the ERG.A: ERG b-wave amplitude (µV) as a function of flash brightness (cd/m2) in four experimental groups. As for other data, each point represents the group mean and error bars show standard deviations of the mean. B: The amplitude of the b-wave normalized to control values in the 5 experimental groups. Histogram bars show means for each experimental group; error bars show standard deviations of the mean. The comparisons were made from data obtained at a fixed value of luminance (10 cd/m2) before saturation. Single treatment with saffron and PBM mitigated the b-wave reduction induced by light damage, and the differences between treated and untreated groups were significant. Combined treatment also mitigated the reduction of the b-wave, but the difference was not statistically significant. C: Representative traces for each group to a stimulus flash of 10 cd/m2 of luminance. The error bars show standard errors of the mean. Statistical significance indicators: (***) p<0.001; (**) p<0.01, (*) p<0.05.
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pone-0100389-g004: Impact of single and combined neuroprotectants on the ERG.A: ERG b-wave amplitude (µV) as a function of flash brightness (cd/m2) in four experimental groups. As for other data, each point represents the group mean and error bars show standard deviations of the mean. B: The amplitude of the b-wave normalized to control values in the 5 experimental groups. Histogram bars show means for each experimental group; error bars show standard deviations of the mean. The comparisons were made from data obtained at a fixed value of luminance (10 cd/m2) before saturation. Single treatment with saffron and PBM mitigated the b-wave reduction induced by light damage, and the differences between treated and untreated groups were significant. Combined treatment also mitigated the reduction of the b-wave, but the difference was not statistically significant. C: Representative traces for each group to a stimulus flash of 10 cd/m2 of luminance. The error bars show standard errors of the mean. Statistical significance indicators: (***) p<0.001; (**) p<0.01, (*) p<0.05.

Mentions: Figure 4 shows the impact of PBM, saffron and combined conditioning on the preservation of retinal function. We recorded ERG responses as a function of increasing flash intensity (Figure 4A), from threshold to saturation. Figure 4C shows representative ERG traces obtained at a fixed luminance (10 cd/m2), less than saturation. Quantitative results for different treatments are summarized in Figure 4B as a percentage of control amplitude of the b-wave. The amplitude was strongly reduced after light damage (70% reduction). Pre-conditioning with 7 d PBM and 10 d saffron mitigated the reduction, to 40% and 50% respectively. Preconditioning with both PBM and saffron, given simultaneously did not increase the mitigation. We recorded responses as a function of increasing luminance from threshold to saturation. Comparison were made from data obtained at a fixed value of luminance (10 cd/m2), which was non-saturating.


Combining neuroprotectants in a model of retinal degeneration: no additive benefit.

Di Marco F, Di Paolo M, Romeo S, Colecchi L, Fiorani L, Spana S, Stone J, Bisti S - PLoS ONE (2014)

Impact of single and combined neuroprotectants on the ERG.A: ERG b-wave amplitude (µV) as a function of flash brightness (cd/m2) in four experimental groups. As for other data, each point represents the group mean and error bars show standard deviations of the mean. B: The amplitude of the b-wave normalized to control values in the 5 experimental groups. Histogram bars show means for each experimental group; error bars show standard deviations of the mean. The comparisons were made from data obtained at a fixed value of luminance (10 cd/m2) before saturation. Single treatment with saffron and PBM mitigated the b-wave reduction induced by light damage, and the differences between treated and untreated groups were significant. Combined treatment also mitigated the reduction of the b-wave, but the difference was not statistically significant. C: Representative traces for each group to a stimulus flash of 10 cd/m2 of luminance. The error bars show standard errors of the mean. Statistical significance indicators: (***) p<0.001; (**) p<0.01, (*) p<0.05.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4067315&req=5

pone-0100389-g004: Impact of single and combined neuroprotectants on the ERG.A: ERG b-wave amplitude (µV) as a function of flash brightness (cd/m2) in four experimental groups. As for other data, each point represents the group mean and error bars show standard deviations of the mean. B: The amplitude of the b-wave normalized to control values in the 5 experimental groups. Histogram bars show means for each experimental group; error bars show standard deviations of the mean. The comparisons were made from data obtained at a fixed value of luminance (10 cd/m2) before saturation. Single treatment with saffron and PBM mitigated the b-wave reduction induced by light damage, and the differences between treated and untreated groups were significant. Combined treatment also mitigated the reduction of the b-wave, but the difference was not statistically significant. C: Representative traces for each group to a stimulus flash of 10 cd/m2 of luminance. The error bars show standard errors of the mean. Statistical significance indicators: (***) p<0.001; (**) p<0.01, (*) p<0.05.
Mentions: Figure 4 shows the impact of PBM, saffron and combined conditioning on the preservation of retinal function. We recorded ERG responses as a function of increasing flash intensity (Figure 4A), from threshold to saturation. Figure 4C shows representative ERG traces obtained at a fixed luminance (10 cd/m2), less than saturation. Quantitative results for different treatments are summarized in Figure 4B as a percentage of control amplitude of the b-wave. The amplitude was strongly reduced after light damage (70% reduction). Pre-conditioning with 7 d PBM and 10 d saffron mitigated the reduction, to 40% and 50% respectively. Preconditioning with both PBM and saffron, given simultaneously did not increase the mitigation. We recorded responses as a function of increasing luminance from threshold to saturation. Comparison were made from data obtained at a fixed value of luminance (10 cd/m2), which was non-saturating.

Bottom Line: Results confirmed the neuroprotective potential of each used separately, but gave no evidence that their effects are additive.Detailed analysis suggests that there is actually a negative interaction between PBM and saffron when given simultaneously, with a consequent reduction of the neuroprotection.Specific testing will be required to understand the mechanisms involved and to establish whether there is clinical potential in combining neuroprotectants, to improve the quality of life of people affected by retinal pathology, such as age-related macular degeneration, the major cause of blindness and visual impairment in older adults.

View Article: PubMed Central - PubMed

Affiliation: Department of Biotechnology and Applied Clinical Science, University of L'Aquila, L'Aquila, Italy.

ABSTRACT
The central nervous system undergoing degeneration can be stabilized, and in some models can be restored to function, by neuroprotective treatments. Photobiomodulation (PBM) and dietary saffron are distinctive as neuroprotectants in that they upregulate protective mechanisms, without causing measurable tissue damage. This study reports a first attempt to combine the actions of PBM and saffron. Our working hypothesis was that the actions of PBM and saffron in protecting retinal photoreceptors, in a rat light damage model, would be additive. Results confirmed the neuroprotective potential of each used separately, but gave no evidence that their effects are additive. Detailed analysis suggests that there is actually a negative interaction between PBM and saffron when given simultaneously, with a consequent reduction of the neuroprotection. Specific testing will be required to understand the mechanisms involved and to establish whether there is clinical potential in combining neuroprotectants, to improve the quality of life of people affected by retinal pathology, such as age-related macular degeneration, the major cause of blindness and visual impairment in older adults.

Show MeSH
Related in: MedlinePlus