Colchicine pre-treatment and post-treatment does not worsen bleeding or functional outcome after collagenase-induced intracerebral hemorrhage

Abstract

Patients with intracerebral hemorrhage (ICH) are at increased risk for major ischemic cardiovascular and cerebrovascular events. However, the use of preventative antithrombotic therapy can increase the risk of ICH recurrence and worsen ICH-related outcomes. Colchicine, an anti-inflammatory agent, has the potential to mitigate inflammation-related atherothrombosis and reduce the risk of ischemic vascular events. Here we investigated the safety and efficacy of colchicine when used both before and acutely after ICH. We predicted that daily colchicine administration would not impact our safety measures but would reduce brain injury and improve functional outcomes associated with inflammation reduction. To test this, 0.05 mg/kg colchicine was given orally once daily to rats either before or after they were given a collagenase-induced striatal ICH. We assessed neurological impairments, intra-parenchymal bleeding, Perls positive cells, and brain injury to gauge the therapeutic impact of colchicine on brain injury. Colchicine did not significantly affect bleeding (average = 40.7 μL) at 48 hrs, lesion volume (average = 24.5 mm3) at 14 days, or functional outcome (median neurological deficit scale score at 2 days post-ICH = 4, i.e., modest deficits) from 1-14 days after ICH. Colchicine reduced the volume of Perls positive cells in the perihematomal zone, indicating a reduction in inflammation. Safety measures (body weight, food consumption, water consumption, hydration, body temperature, activity, and pain) were not affected by colchicine. Although colchicine did not confer neuroprotection or functional benefit, it was able to reduce perihematomal inflammation after ICH without increasing bleeding. Thus, our findings suggest that colchicine treatment is safe, unlikely to worsen bleeding, and is unlikely but may reduce secondary injury after an ICH if initiated early post ICH to reduce the risk of ischemic vascular events. These results are informative for the ongoing CoVasc-ICH phase II randomized trial (NCT05159219).

Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1. Experiment 1 safety measures.

Body weight steadily increased in all animals (A) across experiment 1. Water (B) and food consumption (C) did not decrease by more than 20%, indicating little cause for concern. Pain (D) did not increase by more than 2 points in any animals, indicating the treatment was well tolerated. Body temperature (E) did not differ from baseline by more than 1°C in any animals, at any point in time. Dosing did not affect observed activity levels (F). Temperature and activity are graphed as difference from baseline (averaged hourly to account for circadian rhythms), where a positive reading means that animals were hotter/more active post-treatment. Lines represent individual animals.

Fig 2. Experiment 2.

ICH significantly worsened NDS at 48 hours post-ICH (A, p0.999). n = 10/group.

Fig 3. Experiment 2 hematoma volume and cell counts.

No differences in hematoma volume (A, p = 0.168), or cell density in the peri-hematoma zone (B, p = 0.071) were found at 48 hours post-ICH. C. Representative image of neurons in the PHZ stained using cresyl violet. White scale bar represents 50 μm, black scale bar represents 1 mm.

Fig 4. Experiment 3 edema and behaviour.

ICH significantly worsened NDS scores at 48 hours post-ICH (A, p

Fig 5. Experiment 4 behaviour and lesion volume.

ICH significantly worsened NDS at all times post-ICH (A, p0.507) or ladder task (p = 0.791) were found between groups at any time. Lesion volume at 14 days post-stroke (C) was not affected by colchicine administration (p = 0.9848). D. Representative image of an animal from the colchicine group with a lesion volume of 21.47 mm3. This animal demonstrates ventriculomegaly and the hematoma resolution at 14 days post-ICH. Scale bar represents 1 mm.

Fig 6. Experiment 4 Perls staining.

Post-ICH colchicine administration did not affect the number of Perls positive cells per region of interest (A, p = 0.115), but did reduce the average volume of brain containing Perls positive cells (B, p = 0.018, average area of blue tissue multiplied by section interval and number of sections) at 14 days post-ICH. C. Perls positive cells under 40 × magnification. D. Representative image of Perls staining. White scale bar represents 20 μm, black scale bar represents 1 mm.