Milosavljevic I, Jakovljevic V, Petrovic D., et al. Standardized Aronia melanocarpa extract regulates redox status in patients receiving hemodialysis with anemia. Mol Cell Biochem. November 2021;476(11):4167-4175. doi: 10.1007/s11010-021-04225-y.
Chronic kidney disease (CKD) is a global health concern. Standard treatment includes hemodialysis. Patients receiving hemodialysis are at high risk of developing complications including anemia, bone disease, heart disease, and electrolyte imbalance. Anemia is associated with erythropoietin deficiency and a reduction of red blood cell survival. Anemia is associated with high morbidity and mortality. Oxidative stress and inflammation are involved in the pathogenesis of complications associated with CKD including anemia. During hemodialysis, molecules with antioxidant potential are removed. Additionally, vitamin E and C serum levels and antioxidant enzymes are often lower. Standard drug therapy includes erythropoietin.
Studies have shown that plants high in flavonoids may reduce oxidative stress and inflammation in patients receiving hemodialysis. Aronia berry (Aronia melanocarpa, Roseaceae) is a rich source of polyphenols including anthocyanins and flavonoids. Previous studies have shown that aronia berry exerts beneficial effects in chronic diseases connected with oxidative stress. Recent studies conducted by the same authors have shown that standardized aronia berry extract (SAE) has the potential to reduce oxidative stress and increase iron in rats with metabolic syndrome. The purpose of this single-arm pilot study was to evaluate the effects of one-month consumption of SAE on oxidation-reduction reaction (redox) status in patients on hemodialysis with anemia.
Thirty patients diagnosed with CKD undergoing dialysis treatment were recruited from the Center for Nephrology and Dialysis of the Clinical Center Kragujevac (Kragujevac, Serbia). Patients undergoing regular dialysis treatment for more than three months, three times a week and with hemoglobin values between 80 g/L and 100 g/L were included. Exclusion criteria included the use of antioxidants and immunosuppressants, presence of malignancies, active bleeding, and presence of inflammation or active infection. A flow diagram was not included. Additionally, all patients were treated with Epoetin alfa 2000 IU (Epogen®; Amgen, Inc.; San Francisco, CA) three times per week.
SAE was prepared by EU-Chem Company (Belgrade, Serbia). SAE contained 400 mg/30 mL of polyphenols, of which anthocyanins and flavonoids were the most abundant. Patients were instructed to consume 30 mL/day for 30 days. Blood samples were collected at baseline and the end of the study.
Nineteen men and 11 women were enrolled in the study. Common comorbidities included diabetes (n = 2), hypertension (n = 21), or both (n = 7). In addition to dialysis, patients were commonly prescribed ACE-inhibitors and ARBs (n = 22). The average age was 62.93 ± 11.28 years with a body mass index of 25.82 ± 5.02 kg/m2. No significant differences in baseline characteristics were noted.
A significant increase in hemoglobin and haptoglobin levels were observed after one month of SAE supplementation (P = 0.018 and P = 0.038, respectively). A significant decrease in lactate dehydrogenase levels and ferritin were observed following the intervention (P = 0.042 and P = 0.009, respectively). Superoxide anion radical levels and nitrites decreased significantly following the intervention (P = 0.034 and P = 0.000, respectively). A significant increase in catalase activity (P = 0.017) and a reduced level of glutathione (P = 0.022) were observed after 30 days of treatment with SAE. A small increase in superoxide dismutase activity was shown, although not significant. Inflammatory marker, C-reactive protein, decreased. Leukocytes and tumor necrosis factor alpha increased. However, none of these changes were significant.
One limitation of this study included its short duration. Another limitation may be the comorbidities of the patients involved in the study which may have altered the results. Nonetheless, the authors conclude that SAE consumption over a 30-day period may regulate redox status and provide beneficial effects on anemia parameters in patients undergoing hemodialysis. Results do not support the efficacy of SAE as an anti-inflammatory agent for patients diagnosed with CKD who are anemic due to hemodialysis. However, chronic supplementation with antioxidant polyphenol rich SAE may be useful due to its beneficial effects on anemic and redox status. Further investigation is needed to support and further delineate these findings.
The authors declare no conflict of interest.
—Samaara Robbins