Renal ischemia-reperfusion injury (IRI) is an inevitable consequence of several conditions and procedures including renal transplantation and partial nephrectomy. Recently, there has been a growing interest in using natural phytochemical compounds as treatment alternatives due to their relatively low toxicity, low price and wide availability. Dihydromyricetin, which is a flavonoid extracted from the stems and leaves of the ampelopsis grossedentata (vine tea), has been proven to be effective in some conditions. The aim of this study was to investigate the effect of dihydromyricetin on the renal alterations associated with renal ischemia-reperfusion injury.

Studies were performed on Wistar rats. Dihydromyricetin was dissolved in a vehicle containing 0.5% carboxymethyl cellulose and administrated orally as a single dose of 400 mg/kg for 10 days before IRI and continued for 96 hours post-IRI. G-Sham (n=10) underwent sham surgery whereas G-IRI (n=10) and G-IRI/DHM (n=10) underwent bilateral warm renal ischemia for 35 minutes and received the vehicle or dihydromyricetin, respectively. Renal functions were assessed 96 hours after ischemia. From previous similar studies in rats, ten animals per group was sufficient demonstrate any significant differences [1, 2].

Neither dihydromyricetin nor the vehicle had affected the basal renal functions. Dihydromyricetin significantly attenuated the alterations in serum creatinine (0.34±0.03 vs. 0.83±0.17), urea (78.9±6.66 vs.151.7±39.0), creatinine clearance (1.52±0.16 vs. 0.83±0.17) and urinary albumin creatinine ratio (0.14±0.02 vs. 0.20±0.01) when comparing G-IRI/DHM to G-IRI (P<0.05 for all). Dihydromyricetin also ameliorated the alterations in markers of renal injury, pro-apoptotic gene, oxidative stress markers and histological changes. For instance, the gene expression of kidney injury molecule-1 (KIM-1) and neutrophil gelatinase-associated lipocalin (NGAL) in the G-IRI/DHM and G-IRI were (370±63 vs.622±56) and (19.4±3.2 vs. 30.6±2.9), respectively (P<0.05 for both).

Dihydromyricetin mitigated the alteration in renal functions, markers of renal injury, pro-apoptotic gene, oxidative stress markers and histological changes caused by renal ischemia-reperfusion injury.

Dihydromyricetin has a reno-protective effect on the IRI-induced renal dysfunction as it significantly ameliorated the alterations in kidney functions, kidney injury markers, pro-apoptotic gene, oxidative stress markers and the histological changes. These findings could be of clinical importance.

Hammad, F.T., et al., The effect of neprilysin and renin inhibition on the renal dysfunction following ischemia-reperfusion injury in the rat. Physiol Rep, 2021. 9(6): p. e14723.
Hammad, F.T., A.M. Wheatley, and G. Davis, Role of endothelin ET(A) receptor antagonism in the post-transplant renal response to angiotensin II in the rat. Exp Physiol, 2001. 86(3): p. 365-72.