Lingonberry juice consumption protects the kidney against ischemic-reperfusion injury

Lingonberry (Vaccinium vitis-idaea) contains high levels of anthocyanins and polyphenols which may be protective against ischemia-reperfusion (IR) injury in the kidney. This type of acute kidney injury is common during kidney transplant, coronary artery bypass grafting, and other major surgeries. Since these types of surgeries are often preceded by waiting periods, a pretreatment approach may be appropriate. This study investigated the effects of lingonberry juice consumption on kidney injury, inflammation, and antioxidant defenses after IR-induced kidney injury. 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, blood flow was re-established, and then reperfusion was allowed for 6 hours prior to sacrifice. 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 largely affect antioxidant defenses. 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.