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The antimalarial drug, chloroquine (CQ), has been reported as an autophagy inhibitor in a variety of disorders, including Alzheimer's disease and brain ischemia. To the best of our knowledge, no studies to date have examined the potential for CQ to provide neuroprotection in animal models of traumatic brain injury (TBI). The aim of this study was to investigate the neuroprotective actions of CQ in TBI and to determine the mechanisms underlying this effect. Rats were immediately subjected to a diffuse cortical impact injury caused by a modified weight-drop device and divided randomly into three groups: sham-operated, CQ treatment and vehicle. The CQ treatment group was administered CQ (intraperitoneally, 3 mg/kg body weight) immediately following the induction of injury. The co-localization of neuron-specific nuclear protein (NeuN) and microtubule-associated protein 1 light chain 3 (LC3), was followed by immunofluorescent staining. The expression of LC3 and inflammatory cytokines was identified by western blot analysis. Wet-dry weight method was utilized to evaluate TBI-induced brain edema. Motor function was evaluated using the Neurological Severity Score (NSS) scale and the Morris water maze was employed to assess spatial learning ability. This study demonstrated that the administration of CQ attenuates TBI-induced cerebral edema, and the associated motor and cognitive functional deficits that occur post-injury. Following the induction of cerebral trauma, CQ treatment significantly suppressed neuronal autophagy and reduced expression levels of the inflammatory cytokines, interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), in the rat hippocampus. Our results have provided in vivo evidence that CQ may exert neuroprotective effects following TBI, in attenuating brain edema and improving neurological functioning, by reducing the damaging consequences of neuronal autophagy and cerebral inflammation. [ABSTRACT FROM AUTHOR]

The P2X7 inhibitor, brilliant blue G (BBG), has been reported as a neuroprotective drug against a variety of disorders, including neuropathic pain and brain ischemia. Currently, no studies have examined the potential for BBG to provide neuroprotection in animal models of TBI. The aim of the present study was to investigate the neuroprotective effect of BBG on TBI and to determine the underlying mechanisms. The rats were subjected to a diffuse cortical impact injury caused by a modified weight-drop device, and then divided randomly into three groups: the sham-operated, BBG treatment and vehicle groups. In the BBG treatment group, 50 mg/kg brilliant blue G (BBG; 100% pure), a highly specific and clinically useful P2X7 antagonist, was administered via the tail vein 15 min prior to or up to 8 h following TBI. The co-localization of NeuN and protein kinase Cγ (PKCγ) was followed with immunofluorescent staining. The expression of P2X7, PKCγ and inflammatory cytokines was identified by western blot analysis. Wet-dry weight method was used to evaluate brain edema, and motor function outcome was examined using the neurological severity score. The present study demonstrated that the administration of BBG attenuated TBI-induced cerebral edema and the associated motor deficits. Following trauma, BBG treatment significantly reduced the levels of PKCγ and interleukin-1β in the cortex. The results provide in vivo evidence that BBG exerted neuroprotective effects by attenuating brain edema and improving neurological functions via reducing PKCγ and interleukin-1β levels following TBI. [ABSTRACT FROM AUTHOR]