Background: Ischemia reperfusion injury following acute ischemic insult is responsible for extension of injury.Bosentan is an endothelin receptor antagonist, which is currently used as a strong vasoconstrictor. This study aims to investigate the effects of bosentan on ischemia reperfusion injury after brain ischemic stroke in rat model. Methods: Forty male Wistar rats were randomly allocated into four study groups: Sham group: Rats underwent the anesthesia & surgery for an identical period to the other 3 study groups without intervention. Control group: Rats underwent anesthesia & surgery including bilateral common carotid artery ligation (BCCAL) for 30 minutes and then reperfusion for 1 hour. Vehicle group: Four days before ischemia, rats were administered with a vehicle (5% gummi arabicum) and then anesthesia &BCCAL surgery were performed. Bosentan treat group: Four days before Al-Aubaidy et al (2019): Bosentan effect in brain ischemia September 2019 Vol. 22(IV) ©Annals of Tropical Medicine & Public Health SPe145ischemia, rats were administered with bosentan (100mg/ kg/day) and then anesthesia & BCCAL surgery were performed.Results: Bosentan treated group exhibited lower concentration of interleukin 6 (IL-6)in the brain (2168.0±30.67 pg/mL) than in the control group (2571.37±96.58 pg/mL) (P≤0.05). In addition, interleukin 10 (IL-10) levels were significantly high in the bosentan group (275.7±15.97 pg/mL) when compared to the control group (244.05±12.23 pg/mL) (P≤0.05). This was associated with a non-significant reduction in the brain levels of endothelia nitric oxide synthase (eNOS) in the bosentan treated groups (90.23±1.14 ng/mL) when compared to the control group (90.94±2.48), (P>0.05). Conclusion:Bosentan treatment have protective effects against the inflammatory damage following ischemia reperfusion injury following acute myocardial infarction.

Objectives: An association between COVID-19 and anosmia has been demonstrated worldwide. Calcium cations play an essential role in odor transmission, including feedback inhibition. Therefore, it is suggested that reducing intranasal free calcium cations with topical chelating agent pentasodium diethylenetriamine pentaacetate may improve olfactory function in patients with anosmia post COVID-19 infection. Design: Prospective controlled clinical trial to test use of pentasodium diethylenetriamine pentaacetate for post COVID-19 olfactory loss. Setting: ENT Department (Institution blinded for review). Participants: Sixty-six adult patients with history of confirmed COVID-19 and olfactory dysfunction persisted more than 90 days after SARS-CoV-2 negative testing were included. Main outcome measures: Participants were divided into 2 equal groups receiving nasal spray containing either 0.9% sodium chloride or 2% pentasodium diethylenetriamine pentaacetate. Olfactory function was assessed before treatment and 1 month later using the Sniffin’ Sticks test. A carbon paste ion-selective electrode was developed for quantitative analysis of calcium cation concentrations in nasal mucus before treatment and 1 month later. Results: After treatment with pentasodium diethylenetriamine pentaacetate, there was a significant improvement from functional anosmia to hyposmia compared with sodium chloride. In addition, the decrease of calcium concentration was recorded after treatment with pentasodium diethylenetriamine pentaacetate compared with sodium chloride. Conclusion: Based on the results of the proposed study, topical use of pentasodium diethylenetriamine pentaacetate may be a useful therapy for olfactory dysfunction after COVID-19.