Impaired Renal Function Due to Reductive Stress Associated with Excessive Consumption of <em>Hibiscus sabdariffa Linnaeus</em>

Reductive stress (RS) results from the overactivity of the enzymatic and non-enzymatic antioxidant systems and from excess antioxidant agents that neutralize reactive oxygen species. Hibiscus sabdariffa Linnaeus (HSL), is a natural source of antioxidant molecules which can overload the antioxidant system. Twenty-one Wistar rats were divided into three groups: G1: rats that consumed 6% HSL infusion for one month (HSL + 6 %), G2: rats that consumed 6 % HSL infusion for one month and were then given natural water for another month (HSL ± 6%), and G3: rats with natural drinking water (C). Renal vascular resistance (RVR) was evaluated through the responses to norepinephrine (Ne), acetylcholine (Ach), O2–, H2O2 and ONOO–. The activity of antioxidant enzymes and oxidative stress markers were evaluated in the kidney. RVR was increase by Ne and H2O2 (p=0.03), but it was decreased by Ach, O2–and ONOO– (p=0.01). GSH/GSSG and nitrates/nitrites, the total antioxidant capacity, and the activities of SOD, catalase, peroxidases, GPx, GR, glucose-6-phosphate, and the Nrf2 expression were increased (p≤0.04). However, thiol groups, adenochrome, and glutathione-S-transferase were decreased (p=0.01) in the G1 vs. G2 and G3. Excessive consumption antioxidants provided by 6 % HSL infusion results in RS contributing to decrease ROS.