The Neuroprotective Effect of Nano/submicron and Blended Lycium barbarum for Experiment Retinal Ischemia and Reperfusion Injury in Rats
Date Issued
2011
Date
2011
Author(s)
Wu, I-Han
Abstract
Ocular hypertension or glaucoma results in retinal ischemia and consequent death of optical neural cells. Lycium barbarum (LB) has been known for nourishing the liver and kidney, improving visual acuity for more than 2,500 years in oriental countries. Further, nanotechnology has been minimize particle size in order to achieve more effective bioavailability. Media milling of LB who used to reduce the material size to nano/submicron scale, which was attributed to higher extractive efficiency of bioactive components (dietary fiber, total carotenoids, beta-carotene and crude polysaccharides).
To evaluate the neuroprotective effect of the Chinese herb Lycium barbarum with different particle sizes, we established an experimental rat model of ocular hypertension to evaluate features of retinal ischemia as a basis of further research in prevention and management of retinal ischemia. A stable animal model of ocular hypertension has been successfully established and characterized in the rat. In this study, we adopted electroretinography (ERG), histopathological analysis, and assayed for levels of antioxidants (Reduced glutathione and glutathione, GSH and GSSH), antioxidative enzymes (Catalase and superoxide dismutase, SOD) and peroxidants (Malondialdehyde, MDA) to evaluate the neuroprotective effect of nano/submicron LB on retinal functions in an experimental model of retinal ischemia.
With different particle sizes (blended or milled) and different doses (500 mg/kg、250 mg/kg、100 mg/kg) of LB, we evaluated its neural protective and antioxidative effects on retinal ischemia. The amplitude of a and b waves were preserved in rats treated with blended or milled LB groups of different doses compared with untreated group in a wave (55-60%) and b wave (43-62%). In all LB treated groups, the preservation of retinal function following retinal ischemia was observed. The best neuroprotective effect in b-wave amplitudes of ERG was observed in the 250 mg/kg milled LB group. In terms of antioxidative capacity of retina, levels of GSSH+GSH, SOD, and catalase of all LB groups were higher than those in untreated groups, and the MDA was lower than that in untreated groups. Blended and milled L. barbarum both protected retina. To sum up, the better antioxidative effect was observed in the 250 mg/kg milled and 500 mg/kg blended LB than other group. In the plasma, there was no significant difference in levels of GSSH+GSH and catalase between the LB treated groups and untreated groups. There was higher levels of SOD and lower levels of MDA in the plasma of LB treated groups compared with untreated group.
In conclusion, LB, especially 250 mg/kg milled LB, provided retinal neuroprotective effects in preservation of retinal structure and function with improved antioxidative capacity in the rats with high intraocular pressure induced retinal ischemia.
Subjects
Retinopathy, Glaucoma, Retinal ischemia, Nanotechnology, Neuroprotection, Lycium barbarum, Antioxidant
Type
thesis
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