Role of mitochondrial permeability transition in the immature brain following intrauterine ischemia

Hesperidin ameliorates immobilization-stress-induced behavioral and biochemical alterations and mitochondrial dysfunction in mice by modulating nitrergic pathway

The present study was aimed to evaluate the protective effect of hesperidin against immobilization-stress-induced alterations in biochemical, behavioral, and mitochondrial functions in mice. In many instances neuroscientists have reported that acute immobilization stress for 6 h resulted in anxiety and impaired locomotor activity due to excess oxidative-nitrergic stress, depletion of antioxidant defense mechanisms, and mitochondrial dysfunction in animals. In the present study, 6 h of acute immobilization stress had significantly altered the behavioral (anxiety and memory) and biochemical parameters coupled with mitochondrial dysfunction in Swiss albino mice. Fourteen days of pretreatment with Hesperidin (50 and 100 mg/kg, p.o.) significantly and dose-dependently inhibited the behavioral and biochemical alterations and mitochondrial dysfunction caused by acute immobilization stress. Furthermore, pre-treatment of l-arginine (50 mg/kg, i.p.), a nitric oxide precursor, reversed the protective effect of Hesperidin (50 and 100 mg/kg) (P < 0.05). In contrast, pretreatment of l-NAME (5 mg/kg, i.p.), a nitric oxide synthase inhibitor, potentiated the protective effect of Hesperidin (P < 0.05). These results suggest the possible involvement of nitrergic pathway in the protective effect Hesperidin against immobilization-stress-induced behavioral, biochemical, and mitochondrial dysfunction in mice.

Results of and further prevention of hypoxic fetal brain damage by inhibition of xanthine oxidase enzyme with allopurinol

Several experimental models on adult and newborn animals showed that in cerebral hypoxic-ischemic conditions similar to clinical states the main source of the excessive production of free oxygen radicals is the highly activated xanthine oxidase (XO) enzyme reaction. Long before this data were available, it became known that the main role of allopurinol (AP) is the inhibition of XO. On the basis of these results, many therapeutic trials with AP were performed both in experimental and clinical studies of ischemia and reperfusion. However, it has been shown that only preventive administration of AP has favorable effects. The explanation for the poor results of AP treatment in human fetal brain damage (FBD) cases is that the drug was applied postnatally. The clinical studies performed in healthy laboring mothers whose deliveries were complicated with FBD showed that placental transfer after prenatal administration of AP may be effective in protecting newborns at increased risk of hypoxic-ischemic cerebral damage. Further controlled trials are required to determine if the prophylactic use of the drug might prevent hypoxic-ischemic injuries when the drug is administered immediately prior to impending fetal hypoxia, or even in deliveries at risk of developing hypoxia.

Behavioral, biochemical and cellular correlates in the protective effect of sertraline against transient global ischemia induced behavioral despair: possible involvement of nitric oxide-cyclic guanosine monophosphate study pathway

Post-stroke depression (PSD) is one of the psychiatric complications after stroke. Present study was conducted to elucidate the protective effect of sertraline and possible involvement of nitric oxide mechanism against transient global ischemia induced behavioral despair. Bilateral common carotid artery occlusion was given twice for 5 min at 10 min interval followed by 96 h reperfusion. Ischemia reperfusion significantly increased immobility period and decreased resistance to lateral push as compared to sham-operated group. Ischemia reperfusion caused significant oxidative damage and mitochondrial enzyme complex (I-III) dysfunction as compared to sham group. Sertraline (5 and 10mg/kg) treatment significantly reduced immobility period, increased resistance to lateral push, attenuated oxidative damage and restored mitochondrial enzyme complex activities as compared to ischemia group. L-Arginine (100mg/kg) or sildenafil (5mg/kg) pretreatment with sertraline (5mg/kg) significantly reversed the protective effect of sertraline. However, L-NAME (10mg/kg) or 7NI (10mg/kg) pretreatment with sertraline (5mg/kg) significantly potentiated their protective effect which were significant as compared to their effect alone. The present study shows that nitric oxide modulation is involved in the protective effect of sertraline.

Hypoxic-ischemic encephalopathy in the term infant

Hypoxia-ischemia in the perinatal period is an important cause of cerebral palsy and associated disabilities in children. There has been significant research progress in hypoxic-ischemic encephalopathy over the last 2 decades, and many new molecular mechanisms have been identified. Despite all these advances, therapeutic interventions are still limited. In this article the authors discuss several molecular pathways involved in hypoxia-ischemia, and potential therapeutic targets.