title: Tocotrienol vitamin E protects against preclinical canine ischemic stroke by inducing arteriogenesis.
abstract: Vitamin E consists of tocopherols and tocotrienols, in which α-tocotrienol is the most potent neuroprotective form that is also effective in protecting against stroke in rodents. As neuroprotective agents alone are insufficient to protect against stroke, we sought to test the effects of tocotrienol on the cerebrovascular circulation during ischemic stroke using a preclinical model that enables fluoroscopy-guided angiography. Mongrel canines (mean weight=26.3±3.2 kg) were supplemented with tocotrienol-enriched (TE) supplement (200 mg b.i.d, n=11) or vehicle placebo (n=9) for 10 weeks before inducing transient middle cerebral artery (MCA) occlusion. Magnetic resonance imaging was performed 1 hour and 24 hours post reperfusion to assess stroke-induced lesion volume. Tocotrienol-enriched supplementation significantly attenuated ischemic stroke-induced lesion volume (P<0.005). Furthermore, TE prevented loss of white matter fiber tract connectivity after stroke as evident by probabilistic tractography. Post hoc analysis of cerebral angiograms during MCA occlusion revealed that TE-supplemented canines had improved cerebrovascular collateral circulation to the ischemic MCA territory (P<0.05). Tocotrienol-enriched supplementation induced arteriogenic tissue inhibitor of metalloprotease 1 and subsequently attenuated the activity of matrix metalloproteinase-2. Outcomes of the current preclinical trial set the stage for a clinical trial testing the effects of TE in patients who have suffered from transient ischemic attack and are therefore at a high risk for stroke.
authors.affiliation: Department of Surgery, The Ohio State University Medical Center, Columbus, Ohio 43210, USA.
authors.forename: Cameron
authors.initials: C
authors.lastname: Rink
authors.forename: Greg
authors.initials: G
authors.lastname: Christoforidis
authors.forename: Savita
authors.initials: S
authors.lastname: Khanna
authors.forename: Laura
authors.initials: L
authors.lastname: Peterson
authors.forename: Yojan
authors.initials: Y
authors.lastname: Patel
authors.forename: Suchin
authors.initials: S
authors.lastname: Khanna
authors.forename: Amir
authors.initials: A
authors.lastname: Abduljalil
authors.forename: Okan
authors.initials: O
authors.lastname: Irfanoglu
authors.forename: Raghu
authors.initials: R
authors.lastname: Machiraju
authors.forename: Valerie K
authors.initials: VK
authors.lastname: Bergdall
authors.forename: Chandan K
authors.initials: CK
authors.lastname: Sen
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000150:complications* / Q000201:enzymology / Q000503:physiopathology; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D003097:Collateral Circulation / Q000187:drug effects / Q000502:physiology*; D004195:Disease Models, Animal; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D005471:Fluoroscopy; D008279:Magnetic Resonance Imaging; D020781:Matrix Metalloproteinase 1 / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D020521:Stroke / Q000201:enzymology / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D024508:Tocotrienols / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D018696:Neuroprotective Agents; D024508:Tocotrienols; D020778:Matrix Metalloproteinase 2; D020781:Matrix Metalloproteinase 1