Renal protection by lingonberry supplementation
Siow, Y.L., Isaak, C.K., Madduma Hewage, S., Prashar, S., Debnath, S., and O, K. (2019) Renal protection by lingonberry supplementation. FASEB Science Research Conference: The Acute Kidney Injury Conference: From Bench to Bedside (and Back Again). July 21-25, 2019 Pacific Grove, CA, USA.
Background: Acute kidney injury (AKI) is known to be associated with inflammation and frequently triggered by ischemia-reperfusion (IR) injury, mediated by oxidative stress. Ischemic AKI also commonly occurs in patients who underwent cardiac or other major surgeries. Even upon recovery from AKI, some patients experienced a progressive development of chronic kidney disease. As the mortality and morbidity or AKI is quite high with few treatment options besides renal transplantation, alternative approaches are urgently needed. Lingonberry (Vaccinium vitis-idaea L.) is an evergreen shrub native to boreal forests and Arctic tundra throughout the Northern Hemisphere from Eurasia to North America, produces one of the highest antioxidant rich berry commonly consumed. Recent research findings reveals lingonberry exerts antioxidant, antidiabetic, anti-inflammatory, anticancer, antimicrobial, neuroprotection, and vasodilatory effects in various experimental designs at in vitro, in vivo and clinical levels. This study investigated the effects of lingonberry juice consumption on kidney injury, inflammation, and antioxidant defenses after IR-induced kidney injury.
Hypothesis: Lingonberry supplementation is protective for acute kidney injury.
Methods: Male Sprague-Dawley rats were fed either 1 mL of juice made from wild Manitoba lingonberries or sucrose solution (as control) daily for 3 weeks. To induce kidney injury, the left renal pedicle was obstructed for 45 minutes and then blood flow was re-established and reperfusion was allowed for 6 hours prior to euthanization.
Results: Rats subjected to kidney IR had significantly impaired kidney function compared to sham-operated rats, with increased levels of renal JNK activation, renal inflammation, and circulating pro-inflammatory biomarkers. Rats fed lingonberry juice prior to IR had improved kidney function, attenuated inflammatory response, and enhanced antioxidant defenses. In vitro results confirmed that lingonberry anthocyanins reduce JNK signaling and subsequent inflammatory gene expression after IR in proximal tubule cells, but did not significantly affect antioxidant defenses.
Conclusions: This study shows that daily supplementation with lingonberry juice could protect against loss of kidney function induced by ischemic acute kidney injury by modulating JNK signaling and inhibiting the subsequent inflammatory response.