Increasing Neurogenesis with Fluoxetine, Simvastatin and Ascorbic Acid Leads to Functional Recovery in Ischemic Stroke

Abstract

Less than 8.5% of ischemic stroke patients receive clot-busting drugs within the narrow time needed to reduce injury. Thus, there is need for an easily-accessible delayed post-stroke drug treatment to improve functional recovery. Various combinations of fluoxetine, simvastatin, and ascorbic acid were given to healthy rats to assess impact on neurogenesis versus controls. Fluoxetine combined with simvastatin and ascorbic acid produced a 19-fold increase in neurogenesis versus controls in healthy rats; fluoxetine alone produced 10-fold increase. We next tried a couple of drug combinations versus control in endothelin-induced stroked rats. Combined fluoxetine/ simvastatin/ascorbic acid treatment, given to stroked rats 20-26 hours after stroke induction and continued for 31 days, produced strong recovery as measured by Montoya staircase test (mean recovery to 85% of pre-stroke function) and Forelimb Asymmetry test (mean recovery to 90% of pre-stroke function). Fluoxetine and ascorbic acid without simvastatin only produced ~50% of recovery produced by the 3-drug combination. Our results indicate that combined treatment of Fluoxetine, simvastatin and ascorbic acid represents a promising delayed stroke treatment that greatly improves functional recovery in rats and warrants further study in human patient populations. This work formed the basis for a patent submission (US20130065924A1) Composition and method for treatment of neurodegeneration.

The Clinical Features in Subarachnoid Hemorrhage of Unknown Etiology

“…We did not think drug administration this late after stroke induction would have any effect on the infarct volume. The reduction in infarct volume has also correlated with an increase in motor functional recovery, referenced in some of our previous work [6]. We next tested whether an earlier time point for drug delivery would result in further reduction of infarct volume and greater functional recovery, administering the drugs 6-12 hours after stroke induction, a time period over which the majority of stroke patients have been shown to arrive at the hospital [1].…”

“…In contrast to control animals, there does not appear to be damage to the right of the original site, perhaps indicating that reperfusion damage was minimized. Alternatively, the fluoxetine and simvastatin are both known to increase growth factors in the brain, and we have shown in a previous study [6] that one of these growth factors, brain derived neurotrophic factor (BDNF), is elevated around the site of the original infarct; this may allow tissue around the original infarct to survive.…”

“…The basic surgical procedures are as described in a previous study [6], with the following modifications: two holes were drilled in the skull, with positions relative to Bregma of (0.0 mm A.P., 2.5 mm M.L.) and (1.5 mm A.P., and 2.5 mm M.L.).…”

“…Fifty micron coronal slices were cut on a cryostat and collected into phosphate buffered saline. For infarct measurement, these sections were mounted onto gel-subbed slides, then stained with Nissl stain [6], dehydrated and coverslipped with DPX mountant (Sigma-Aldrich).…”

“…Female Sprague-Dawley rats (10-12 months old, 300-400 grams) were initially trained to pick up sucrose pellets in the Montoya Staircase [5] and also tested for forelimb bias using the Forelimb Asymmetry Test [6]. We chose old rats as an animal model to better model the human stroke population, as neurogenesis is decreased in both humans and animals with age [9,10], and the beginning either 6-12 hours or 20-26 hours after stroke induction and continuing daily through post-stroke day 90.…”