Possible Mitigation of Renal Ischemia-Reperfusion Injury With Monk Fruit (Siraitia grosvenori) Extract in a Rat Model

Abstract

Background: Renal ischemia, induced during various kidney surgeries, alarmingly leads to renal inflammation and injuries. We hypothesized that oxidative stress (OXS) could be a primary cause of renal ischemia-reperfusion injury (RIRI), and that antioxidants may mitigate it. Hence, we investigated if monk fruit extract, LLE, with antioxidant activity might reduce the incidence of warm ischemia-induced RIRI in rats.

Methods: Sprague–Dawley rats were randomly assigned to three groups: (1) Sham, (2) ischemia-reperfusion (RIR), and (3) RIR with LLE supplementation (RIR + LLE). The rat kidney was surgically exposed and subjected to 40-min ischemia by renal pedicle clamping, followed by 24-h reperfusion. LLE (150 μg) was given to rats 30 min prior to ischemia and soon after reperfusion began for 24 h.

Results: The RIR group showed significantly elevated blood urea nitrogen (BUN) and creatinine (Cr) levels, indicating renal dysfunction, and palpable kidney injuries/alterations were also detected by histopathologic examination. However, the kidneys in the RIR + LLE group appeared merely normal with significantly reduced BUN/Cr levels. Additionally, the OXS level was ∼2.3-fold greater, two antioxidant enzymes (catalase and glutathione peroxidase) were inactivated, and specific kidney injury markers (neutrophil-gelatinase-associated lipocalin, kidney injury molecule 1, and clusterin) were up-regulated in the RIR group. In contrast, a few changes in OXS, enzymatic activities, and marker expression were observed in the RIR + LLE group.

Conclusion: This study demonstrates that OXS plays a primary role in RIRI, while LLE with antioxidant activity protects the kidneys from it. Thus, LLE warrants consideration as a potential perioperative renoprotective agent for clinical use.