Abstract
Ischemia reperfusion injury (IRI) is considered the main important factor that determined the morbidity and mortality in many disorders as example acute kidney injury (AKI). In certain situations as major surgery and organ transplantation, IRI is considered the main challenge that affected on healing and clinical outcomes. When the ischemic tissue is reperfused by rapidly new blood this will lead to release reactive oxygen species (ROS) from endothelial layer of capillaries and potentiate the inflammatory process and releasing of inflammatory mediators such as tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) and also releasing matrix metalloproteinase 9 enzyme (MMP9). This experimental research is done to examine the possible variation in nephroprotective effect of Olmesartan OLM), Oleuropein (OLE) and their combination on bilateral renal I/R injury in male rats through determining several biomarkers as U & C, IL-1 beta, MMP-9, TAC, Caspase-3 and also through histopathology scores. In this study, 30 adult Wister Albino rats were used with 20-24 weeks in age and weighing 200-350 g. The adult rats were divided randomly into equal 6 groups (5 rats in each group) as (1) Sham Group: all 5 rats underwent the same anesthetic and surgical procedures for an identical period of time for ischemia and reperfusion without ischemia reperfusion induction. (2) Control Group: all 5 rats underwent median laparotomy under anesthesia, followed by 30min bilateral renal ischemia then 2 h of reperfusion.(3) Vehicle Group: all 5 rats pretreated with intraperitoneally injection of DMSO 30 min before ischemia reperfusion injury and undergo bilateral renal ischemia for 30 min and reperfusion for 2 hours. (4) Olmesartan Treated Group: all 5 rats were pretreated with by intraperitoneally injection of Olmesartan 10 mg/kg 30 min before ischemia reperfusion injury and undergo bilateral renal ischemia for 30 min and reperfusion for 2 hours. (5) Oleuropein Treated Group: All 5 rats were pretreated with by intraperitoneally injection of Oleuropein 100 mg/kg 30 min before ischemia reperfusion injury and undergoing bilateral renal ischemia for 30 min and reperfusion for 2 hours. (6) Olmesartan + Oleuropein Treated Group: all 5 rats were pretreated with by intraperitoneally injection of both OLM 10 mg/kg and OLE 100 mg/kg as a combination 30 min before ischemia reperfusion injury and undergoing bilateral renal ischemia for 30 min and reperfusion for 2 h. At the end of this experimental work, we showed that the serum levels of U & C and tissue levels of IL-1 beta, MMP-9 and Caspase-3 in sham, OLM, OLE and their combination groups are significantly lowered than those in control and vehicle groups. As well as, we approved that the levels of those biomarkers in combination group are significantly lowered than those in each OLM and OLE groups alone. While we confirmed that there are no significant variations in the levels of the above biomarkers between OLM and OLE pretreated groups. On the other hand, we showed that the tissue level of TAC in sham, OLM, OLE and their combination groups are significantly higher than those in both control and vehicle groups. As well as, this experimental research approved that the tissue level of TAC in combination treatment group is significantly higher than those in each OLM and OLE treatment groups alone. But there is no significant variation in the tissue level of TAC biomarker between OLM and OLE pretreated groups.
In histopathology examination, we revealed that the OLM, OLE and their combination can significantly reduce the kidney injury in comparison with control and vehicle groups. We also confirmed that the combination treatment is significantly better than each treatment alone in reducing the severity of kidney injury and tubular damage. Also, there are no significant changes in histopathology examination between OLM and OLE pretreated groups. From the overall results, we approved that the OLM, OLE and their combination significantly reduced renal I/R injury in the bilateral renal I/R in adult male rats via their pleiotropic effects as anti-apoptotic, anti-oxidant and anti-inflammatory activities. Also, we revealed that the combination treatment of OLM and OLE is significantly better as a Nephroprotective agent in renal I/R injury than each drug when used alone. And at the same time, there are no significant differences in the Nephroprotective effect between OLM and OLE pretreated groups.