Pre- & post-treatment effect of Lycium Barbarum polysaccharides in an acute ocular hypertension rat model

Lycium Barbarium Polysaccharides (LBP) has been investigated for its neuroprotective effects in both IOP dependent and independent experimental optic neuropathies. The preservation of RGC was demonstrated under pre-treatment conditions, wherein the animals were treated from one week prior to the insult until the end of the study period. In case of real clinical scenario, the drug will be trialled or treated on patients who already have a disease condition. Thus, direct translation of results obtained from the studies tested under pre-treatment conditions may not be sufficient. In order to improve the success in translational neuroprotective drugs, preclinical studies should also evaluate the drug under post-treatment conditions using various models of optic neuropathies.
The present study compares the neuroprotective efficacy of LBP under pre- and post-treatment conditions using an acute ocular hypertension rat model. Also, the study adopted both functional and structural endpoints to longitudinally assess the neuroprotective efficacy of LBP. Under pre-treatment conditions, LBP 10mg/kg showed a longitudinal preservation of inner retinal structure and function. Although the rescue effect of post-treatment of LBP 10mg/kg was not evident initially, it subsequently reduced the further degeneration and functional deterioration as compared to vehicle treatment. We speculate that the post-treatment of LBP could not arrest the initial cascade of events, but reconciled the later cascade of events preventing the secondary degeneration as well as improving the function. Although pre-treatment shows superior neuroprotection, the beneficial effect offered by post-treatment is remarkable as compared to vehicle treatment.