Abstract 2156: Minocycline-induced Attenuation Of Iron Overload And Brain Injury Following Experimental Intracerebral Hemorrhage

Abstract

Background and Purpose: Brain iron overload plays a detrimental role in brain injury after intracerebral hemorrhage (ICH). A recent study found that minocycline acts as an iron chelator and reduces iron-induced neuronal death in vitro. The present study investigated if minocycline reduces iron overload after ICH and iron-induced brain injury in vivo. Methods: This study was divided into three parts. (1) Male Sprague-Dawley rats with different sizes of ICH were euthanized 3 days later for serum total iron and brain edema determination. (2) Rats had an ICH treated with minocycline or vehicle. Rats were euthanized 1, 3 and 7 days later for serum iron, brain iron, and brain iron handling protein measurements. (3) Rats had a 50µl intracaudate injection of either saline, FeCl2, FeCl2+minocycline or FeCl2+macrophage/microglia inhibitory factor and were euthanized at one day later for measurements of brain edema, blood-brain barrier disruption and neuronal death. Results: After ICH, serum total iron and brain non-heme iron increased and these changes were reduced by minocycline treatment (e.g. serum total iron at day 3: 158±36 vs. 245±22 µg/dL in the vehicle-treated group, p<0.01). Minocycline also reduced ICH-induced upregulation of brain iron handling proteins and neuronal death. Intracaudate injection of iron caused brain edema, blood-brain barrier leakage and brain cell death, all of which were significantly reduced by co-injection with minocycline (p<0.05). Conclusions: The current study found that minocycline reduces iron overload after ICH and iron-induced brain injury. It is also well known minocycline is an inhibitor of microglial activation. Minocycline may be very useful for ICH patients because both iron accumulation and microglia activation contribute to brain damage following ICH.