Selank and MIF improve neurological recovery after experimental hemorrhagic stroke in rats
Background
Intracerebral hemorrhage (ICH) carries high mortality and disability rates, with limited neuroprotective pharmacological options in clinical practice. Secondary injury mechanisms — including perifocal edema, neuroinflammation, and mass effect — drive much of the functional deficit. Tuftsin-derived neuropeptides such as MIF (Thr-Lys-Pro) and selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) have shown immunomodulatory and neuroprotective properties, making them candidates for attenuating secondary brain damage. The macrophage-related signaling that tuftsin derivatives modulate may be relevant to hemorrhage-associated neuroinflammation, though their effect on ICH outcomes had not been established prior to this study.
Study Design
A rat model of experimental intracerebral hemorrhage was created via double autologous blood injection into the basal nucleus (n = 15 total). Animals were randomized into three groups (n = 5 each): saline control, MIF at 150 mcg/kg/day i.p., and selank at 300 mcg/kg/day i.p.. Outcome assessments — including body weight, neurological examination using Menzes scale and limb placing test, and brain MRI — were performed at 24 hours, 72 hours, and 10 days post-hematoma formation. Primary endpoints encompassed hematoma volume, perifocal edema, and functional neurological recovery.
Results
Both neuropeptide-treated groups demonstrated significant (p < 0.05) improvement in neurological deficit scores by day 10, as assessed by the Menzes scale and limb placing test, whereas the control group did not show comparable recovery. Reduction in perifocal edema and hematoma volume was observed in all groups by day 10 (p < 0.05), indicating that volumetric resolution occurred regardless of treatment and could not be attributed specifically to neuropeptide administration.
The critical distinction: neuropeptide benefit was confined to functional neurological recovery, not to hematoma or edema resolution — an effect seen only in peptide-treated animals at day 10.
Body weight loss was a significant finding in the control group only (p < 0.05) at day 3, suggesting a general protective or supportive systemic effect of the neuropeptides. No significant early (24 h or 72 h) neurological benefit attributable to either peptide was detected, indicating the recovery effect emerged over time.
Key Findings
- Significant neurological improvement (p < 0.05) seen only in selank and MIF groups at day 10 on Menzes and limb placing test scales
- Hematoma volume and perifocal edema reduced significantly (p < 0.05) by day 10 in ALL groups, including saline control
- Significant body weight loss (p < 0.05) at day 3 observed only in the saline control group
- No significant early (24 h or 72 h) neuropeptide benefit detected; functional gains emerged by day 10
- MIF dosed at 150 mcg/kg/day and selank at 300 mcg/kg/day via intraperitoneal injection
Why It Matters
Selank and MIF may accelerate functional neurological recovery after ICH independently of hematoma clearance, pointing to a neuroprotective mechanism — possibly immunomodulatory — rather than a purely mechanical one. For clinicians and researchers, this suggests that tuftsin-derived peptides could complement strategies targeting secondary injury without requiring direct thrombolytic or volume-reducing action. The intraperitoneal route used here is not directly translatable to human use, and the small group sizes (n = 5) limit statistical power; however, the findings justify larger trials examining i.v. or intranasal routes. From a protocol standpoint, the differing doses — 150 mcg/kg/day for MIF vs. 300 mcg/kg/day for selank — imply these structurally related peptides may have distinct potency profiles worth investigating in dose-finding studies.
TitrateLab articles covering Selank
Written by TitrateLab, separately from the study summarized above.
