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Introduction The effects of edaravone against pentylenetetrazole (PTZ)‐induced epilepsy in male albino rats were investigated. Edaravone is a well‐known commercial drug used in the treatment of strokes and amyotrophic lateral sclerosis (ALS). Antioxidant and free radical scavenging activities of edaravone have been reported in patients with ALS. Methods In this study, the experimental groups were as follows: sham, control, 5 mg/kg edaravone, and 10 mg/kg edaravone. Behavioral assessment, determination of biochemical markers, apoptosis, nitric oxide (NO), and mRNA and protein expression of cyclooxygenase‐II (COX‐II) were carried out. Seizure incidence, including generalized tonic–clonic seizure (GTCS) and minimal clonic seizure (MCS), was directly associated with PTZ administration in rats. Results Edaravone supplementation substantially increased MCS and GTCS latency in rats, and biochemical markers were significantly altered in the brain tissue of PTZ‐treated rats. Edaravone treatment normalized altered biochemical markers compared with the untreated control. Apoptosis and NO levels were significantly reduced by more than 50% compared to their respective controls. COX‐II mRNA was increased by 130% in PTZ‐treated rats, while edaravone supplementation reduced mRNA and protein expression of COX‐II by more than 20% and 40%, respectively. Immunohistochemistry indicated that COX‐II protein expression was reduced by 13.2% and 33.7% following supplementation with 5 and 10 mg/kg edaravone, respectively. Conclusion Taken together, our results suggest that edaravone functions by downregulating the levels of COX‐II and NO and is a potential candidate for the treatment of PTZ‐induced epilepsy.

Prehypertension has been associated with adverse cerebrovascular events and brain damage. The aims of this study were to investigate i) whether short- and long-term treatments with losartan or amlodipine for prehypertension were able to prevent blood pressure (BP)-linked brain damage, and ii) whether there is a difference in the effectiveness of treatment with losartan and amlodipine in protecting BP-linked brain damage. In the present study, prehypertensive treatment with losartan and amlodipine (6 and 16 weeks treatment with each drug) was performed on 4-week-old stroke-prone spontaneously hypertensive rats (SHRSP). The results showed that long-term (16 weeks) treatment with losartan is the most effective in lowering systolic blood pressure in the long term (up to 40 weeks follow-up). Additionally, compared with the amlodipine treatment groups, the short- and long-term losartan treatments protected SHRSP from stroke and improved their brains structurally and functionally more effectively, with the long-term treatment having more benefits. Mechanistically, the short- and long-term treatments with losartan reduced the activity of the local renin-angiotensin-aldosterone system (RAAS) in a time-dependent manner and more effectively than their respective counterpart amlodipine treatment group mainly by decreasing AT1R levels and increasing AT2R levels in the cerebral cortex. By contrast, the amlodipine treatment groups inhibited brain cell apoptosis more effectively as compared with the losartan treatment groups mainly through the suppression of local oxidative stress. Taken together, the results suggest that long-term losartan treatment for prehypertension effectively protects SHRSP from stroke-induced brain damage, and this protection is associated with reduced local RAAS activity than with brain cell apoptosis. Thus, the AT1R receptor blocker losartan is a good candidate drug that may be used in the clinic for long-term treatment on prehypertensive populations in order to prevent BP-linked brain damage.

The current study investigated the efficacy of losartan and amlodipine in protecting spontaneously hypertensive stroke-prone (SHRSP) rats against the risk of stroke. SHRSP rats were administered losartan, amlodipine or the vehicle for 6 weeks. There were no significant differences in systolic blood pressure (SBP) in rats treated with losartan or amlodipine, however, following drug withdrawal, rats treated with losartan maintained reduced SBP for a longer time compared with rats treated with amlodipine. In addition, rats treated with losartan exhibited thinner vascular walls and improved systolic and diastolic function. Clinical stroke scores in the losartan group were significantly reduced compared with those in the amlodipine and vehicle groups. However, rats treated with losartan exhibited higher levels of angiotensin II and lower levels of aldosterone in the serum and brain cortex compared with the vehicle and amlodipine-treated rats. Furthermore, losartan significantly reduced the abnormal expression of angiotensin II receptors type 1 and 2 in SHRSP rats, whilst amlodipine did not. These results suggest that losartan may be more efficacious than amlodipine in ameliorating blood pressure deterioration and reducing stroke risk in SHRSP rats via regulation of the renin angiotensin system.

Resolvin D1 (7S,8R,17S-trihydroxy-4Z,9E,11E,13Z,15E,19Z-docosahexaenoic acid) (RvD1), generated from ω-3 fatty docosahexaenoic acids, is believed to exert anti-inflammatory properties including inhibition of neutrophil activation and regulating inflammatory cytokines. In this study, we sought to investigate the effect of RvD1 in modulating alveolar fluid clearance (AFC) on LPS-induced acute lung injury. In vivo, RvD1 was injected i.v. (5 μg/kg) 8 h after LPS (20 mg/kg) administration, which markedly stimulated AFC in LPS-induced lung injury, with the outcome of decreased pulmonary edema. In addition, rat lung tissue protein was isolated after intervention and we found RvD1 improved epithelial sodium channel (ENaC) α, γ, Na,K-adenosine triphosphatase (ATPase) α1, β1 subunit protein expression and Na,K-ATPase activity. In primary rat alveolar type II epithelial cells stimulated with LPS, RvD1 not only upregulated ENaC α, γ and Na,K-ATPase α1 subunits protein expression, but also increased Na+ currents and Na,K-ATPase activity. Finally, protein kinase A and cGMP were not responsible for RvD1’s function because a protein kinase A inhibitor (H89) and cGMP inhibitor (Rp-cGMP) did not reduce RvD1’s effects. However, the RvD1 receptor (formyl-peptide receptor type 2 [FPR2], also called ALX [the lipoxin A4 receptor]) inhibitor (BOC-2), cAMP inhibitor (Rp-cAMP), and PI3K inhibitor (LY294002) not only blocked RvD1’s effects on the expression of ENaC α in vitro, but also inhibited the AFC in vivo. In summary, RvD1 stimulates AFC through a mechanism partly dependent on alveolar epithelial ENaC and Na,K-ATPase activation via the ALX/cAMP/PI3K signaling pathway.

Fibroblasts, far frombeing merely bystander cells, are known to play a specific role in inflammation resolution after an acute injury. As the endogenous “braking signal,” resolvins possess potent anti-inflammatory and proresolution actions. We demonstrated that the expression of COX-2 protein was significantly peaked initially at 6 hours but then also at 48 hours after LPS stimulation in lung fibroblasts. PGE2levels also peaked at 6 hours, and PGD2levels were increased and peaked at 48 hours. However, no significant change in the protein expression of COX-1 was observed after treatment with LPS in lung fibroblasts. Exogenous resolvin D1 inhibited the first peak of COX-2 expression as well as the production of PGE2induced by LPS. In contrast, exogenous resolvin D1 increased the second peak of COX-2 expression as well as the production of PGD2induced by LPS. In addition, resolvin D1 inhibited COX-2 expression at 6 hours, which was partly through PI3K/AKT and ERK2 signalling pathways.