About the neuroprotection, our animal models are of limited capability to reflect the human neurodegeneration. So a true neuroprotection could be achieved by application of 2-3 drugs, if any. Single drug having such an applicability would be less likely. Here, I would like to suggest regime, instead of single drug. Same is the path for lens which has limited permeability for many drugs e.g. for prevention of cataract.
Dear Farhan, drugs are usually first tested in non-human mammals, after which human-eqiuvalent doses are determined, then clinical trials; the basis for translational studies. Drugs like vits E and C have been validated to be neuroprotective in humans, so, a single agent could be neuroprotective. A battery of drugs may not be necessary, once you understand your target. Best regards.