## 3 Results
### Characteristics of Included Studies  
Twelve articles from the years 1992 to 2018 were included in our qualitative analysis (Table 1). Seven articles reported the effects of tocotrienols in myocardial I/R injury [10; 11; 12; 13; 14; 15; 16], and the other five reported their effects in cerebral I/R injury [17; 18; 19; 20; 21]. In the cerebral I/R injury studies, all except one (a canine model [20]) utilized various types of mice, including ICR [17; 21], C57 BL/6 [19], and ddY [18]. The stroke induction was carried out by the occlusion of the middle cerebral artery (MCA) for 60 min, followed by reperfusion for one day [20] or seven days [17; 21]. Another study performed 90 min of MCA occlusion followed by two days of reperfusion [19], while [PERSON] et al. [18] occluded MCA for 4 h, then reperfusion for 24 h. In terms of treatment, two studies utilized a Tocovid treatment that contained \(\alpha\)-tocotrienol (12.4%), \(\alpha\)-tocopherol (11.3%), \(\beta\)-tocotrienol (2.5%), \(\gamma\)-tocotrienol (19.2%), and \(\delta\)-tocotrienol (6.3%) [17; 21], while another study used a combined tocotrienol pill that contained \(\alpha\)-tocotrienol (61.52 mg), \(\gamma\)-tocotrienol (112.8 mg), and \(\delta\)-tocotrienol (25.68 mg) [20]. Furthermore, other studies administered individualtocrienols [18; 19] and tocopherols [18]. Figure 2: PRISMA flow diagram for the identification of studies via databases. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Author (Year)** & **Animal Characteristics** & **Treatment** & **Effects** \\ \hline \multicolumn{4}{c}{**Brain**} \\ \hline [PERSON] [17] (2018) & ICR mice weighing 23–25 g & 200 mg/kg/day Tocovid for 1 month, given orally. & Neuroprotection via anti-inflammatory effects of 100. \\ [PERSON] [21] (2018) & ICR mice weighing 23–25 g & 200 mg/kg/day Tocovid for 1 month, given orally. & Neuroprotection via antioxidative effects. \\ [PERSON] [20] (2011) & Mongler canings weighing 26.6 \(\pm\) 2.6 kg aged & 200 mg mixed toctorienols & Neuprotective effects via collateral \\  & 2.4 \(\pm\) 0.9 years. & two times a day for 10 weeks. & circulation. \\  & C57 BL/6 mice aged 5 weeks. & 50 mg/kg/day \(\alpha\)-tocotrienol & \\  & Mouse hippocampal HT4 & for 13 weeks, given orally & \\ [PERSON] [19] (2011) & neural cells—primary & via gavage; & Regulation of MRP1 by \(\alpha\)-tocotrienols. \\  & cortical neurons & 1 \(\mu\)mol/L \(\alpha\)-tocotrienol added & \\  & (Sprague-Dawley rats). & 6 h before the glutamate & \\  & & treatment. & \\  & & 0.2 mM or 2 mM of & \\ [PERSON] [18] (2003) & Male ddY mice weighing 25–35 g. & \(\alpha\)-/\(\gamma\)-/\(\delta\)-tocotrienol, given by & Reduction of cerebral infarct \\  & & bolus intravenously 3 h before & volume is more effective in \(\alpha\)-tocotrienol and \(\gamma\)-tocopherol. \\  & & and after MCA occlusion. & \(\gamma\)-tocopherol. \\ \hline \multicolumn{4}{c}{**Heart**} \\ \hline [PERSON] [15] (2012) & Male Sprague-Dawley rats weighing 250–300 g. & 5 mg/kg/day of \(\gamma\)-tocotrienol & Modulation of microRNA that \(\gamma\) regulates angiogenesis. \\  & & Gamma toctorienol is superior in \(\alpha\)-tocotrinection, modulating & \\  & & & numerous genes’ expression, including antioxidants, energy \(\alpha\)-tocotrienol, fatty acid \\  & Adult New Zealand rabbits & 20 \(\mu\)mol/kg/day of \(\alpha\)-/\(\gamma\)-/\(\delta\)-tocotrienols on top of \(2\)\% cholesterol diet. Control & metabolism and calcium \\ [PERSON] [11] (2012) & 2.4–3.0 kg—I/R model. & 2\% cholesterol diet. Control & channels. Interpretation of LPL, \(\gamma\)-2, MMP-9, TGF-\(\beta\), p-Akt, \(\epsilon\)R\(\epsilon\), ER\(\theta\), p-Fox04, and \(\beta\) for 4 weeks. & MMP-2, MMP-9, TGF-\(\beta\), p-Akt, \(\epsilon\)R\(\epsilon\), ER\(\theta\), p-Fox04, and \(\beta\) for 4 weeks. & \\  & & & post-14 were not clear as the \(\alpha\)-tocotrienol with \(\alpha\  
In contrast, most of the studies in myocardial I/R injury models utilized various types of rat models, such as male Sprague-Dawley [10; 11; 14; 15; 16], male Wistar [13], and male Long-Evans [12].