Amazonia Phytotherapy Reduces Ischemia and Reperfusion Injury in the Kidneys

Abstract

Acute kidney injury (AKI) is defined as a sudden decrease in kidney function. Phytomedicines have shown positive effects in the treatment of AKI worldwide. The aim of this study was to evaluate the effect of Abuta grandifolia on the renal function of rats submitted to AKI. A phytochemical study of the plant was performed through liquid chromatography coupled with mass spectrometry (CL-EM) and DPPH and ABTS antioxidant tests. Renal function tests were performed in 20 male adult Wistar rats weighing from 250 to 300 g distributed in the following groups: SHAM (submitted to laparotomy with simulation of renal ischemia); ABUTA (animals that received 400 mg/kg of AG, orally-VO, once a day, for 5 days, with simulation of renal ischemia); I/N (animals submitted to laparotomy for clamping of bilateral renal pedicles for 30 min, followed by reperfusion); ABUTA + I/R (animals that received AG-400 mg/kg, 1× per day, VO, for 5 days, submitted to renal ischemia after treatment with herbal medicine). The results suggest that the consumption of Abuta grandifolia promoted renoprotection, preventing the reduction of renal function induced by ischemia, oxidizing activity, and deleterious effects on the renal tissue, confirmed by the decrease of oxidative metabolites and increase of antioxidants in the animals' organisms.

Keywords: acute kidney disease; ischemia/reperfusion; phytotherapy.

Figure 1

Physiological parameters. (A) Body weight showed no statistically significant differences between the groups. (B) Kidney weight showed a statistically significant increase between the ABUTA + I/R group compared to the SHAM, ABUTA and I/R groups, [F-4.323], p = [p < 0.0001]. (C) Kidney/body weight ratio demonstrated a statistically significant increase between the ABUTA + I/R group compared to the SHAM, ABUTA and I/R groups, [F-6.92], p = [p < 0.0001]. n = 5 per group. Statistical analysis by one-way ANOVA. Values represent the mean ± standard deviation. a: SHAM group.

Figure 2

Renal function. (A) 24-h urinary flow showed a statistically significant increase in the ABUTA + I/R group compared to the SHAM, ABUTA and I/R groups, [F-18.92], p = [p < 0.0001]. (B) Serum creatinine showed a statistically significant decrease in the ABUTA + I/R group compared to the I/R group, [F-31.45], p = [p < 0.0001]. (C) Inulin clearance showed a statistically significant increase among the ABUTA + I/R group compared to the I/R group, [F-35.36], p = [p < 0.0001]. n = 5 per group. Statistical analysis by one-way ANOVA. Values represent the mean ± standard deviation. a: SHAM group; b: ABUTA group; c: Ischemia/Reperfusion Group.

Figure 3

Renal hemodynamics. (A) Heart rate showed a statistically significant increase in the ABUTA group compared to the SHAM, I/R and ABUTA + IR groups, [F-3.628], p = [p < 0.0001]. (B) Mean arterial pressure showed no statistically significant differences between groups, [F-6.89], p = [p < 0.0001]. (C) Renal vascular resistance showed a statistically significant increase in the I/R group compared to the SHAM, ABUTA and ABUTA + IR groups, [F-62.13], p = [p < 0.0001]. (D) Renal blood flow demonstrated a statistically significant increase between the ABUTA + I/R group compared to the I/R group, [F-32.54], p = [p < 0.0001]. Statistical analysis by one-way ANOVA. n = 5 per group. Values represent mean ± standard deviation. a: SHAM group; b: ABUTA group; c: Ischemia/Reperfusion Group.

Figure 4

Oxidative profile. (A) Urinary peroxides demonstrated a statistically significant decrease in the ABUTA + I/R group compared to the SHAM, ABUTA and I/R groups, [F-16.38], p = [p < 0.0001]. (B) Lipid peroxidation showed a statistically significant decrease in the ABUTA + I/R group compared to the SHAM and I/R groups, [F-344], p = [p < 0.0001]. (C) Nitric oxide showed a statistically significant decrease in the ABUTA + I/R group compared to the I/R group, [F-274.2], p = [p < 0.0001]. (D) Renal tissue thiols showed a statistically significant increase in the ABUTA + I/R group compared to the I/R group. [F-21.01], p = [p < 0.0001]. n = 5 per group. Statistical analysis by one-way ANOVA. Values represent the mean ± standard deviation. a: SHAM group; b: ABUTA group; c: Ischemia/Reperfusion Group.

Figure 5

Renal histological analysis showed a statistically significant decrease in the lesions in the renal tissue in the ABUTA + I/R group, in relation to the I/R group, [F-117.3], p = [p < 0.0001]. n = 5 per group. Statistical analysis by one way ANOVA. Values represent mean ± standard deviation. a: SHAM group; b: ABUTA group; c: Ischemia/Reperfusion group.

Figure 6

Renal Histology: necrosis, cellular inflammatory infiltrate, tubular dilation and atrophy. (magnification ×400) of the groups: SHAM (A), ABUTA (B), I/R (C), ABUTA + I/R (D). Black arrows: necrosis; Yellow arrow: Bowman’s space dilation; Red arrow: Infiltration of inflammatory cells; Blue arrow: tubular atrophy; Green arrows: tubular regeneration.