Microalgae (Chlorella vulgaris) attenuates aflatoxin-associated renal injury

Abstract

Introduction: Aflatoxins (AFT) are ubiquitous environmental pollutants that are extremely dangerous for both human beings as well as animals. A safe, effective, and considerate strategy is therefore credited with controlling AFT intoxication. Therefore, our study aimed to evaluate the mitigating properties of Chlorella vulgaris (ChV) against AFT-induced nephrotoxicity and altered egg quality. Methods: Quails were randomized into Control group (receiving a normal diet); ChV group (1 g/kg diet); AFT group (receiving an AFT-containing diet); and the AFT-ChV group were given both treatments. Results and discussion: AFT provoked kidney injury, exhibited by increased renal biochemical parameters and reduced protein levels. Malondialdehyde (MDA) levels dramatically increased as a consequence of AFT exposure, and glutathione (GSH) levels, superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities were also decreased. Substantial up-modulation of the mRNA expression of the inflammatory cytokines (TNF-α, IL-1β, and IL-6) was additionally reported. Furthermore, AFT residues were detected in the egg compromising its quality and nutritional value. Contrarily, ChV supplemented diet suppressed the AFT-prompted oxidative stress and inflammation, together with enhancing the nutritional value and quality of eggs and decreasing AFT residues. These beneficial impacts are proposed to be attributed to its antioxidant and nutritional ingredients. The molecular docking dynamics confirmed the inflammatory and apoptotic protein targets for ChV. Our findings recommend that adding ChV supplements to foods might guard against nephrotoxicity brought on by AFT exposure.

Keywords: Japanese quail; apoptosis; computational modeling; inflammatory cytokines; oxidative stress; residues.

FIGURE 1

Bar-dot plot panel of serum biochemical tests upon ChV and/or AFT exposure. (A) Creatinine, (B) Urea, (C) Uric acid, (D) Total protein, and (E) Albumin. AFT, aflatoxins; ChV, Chlorella vulgaris. Values are represented as mean ± SE (*p < 0.05).

FIGURE 2

Bar-dot plot panel of oxidant/antioxidant indices following ChV and/or AFT treatment in the kidney tissue. (A) MDA, (B) GSH, (C) SOD, and (D) GPx. AFTs, aflatoxins; ChV, Chlorella vulgaris; GPx, glutathione peroxidase; GSH, reduced glutathione; MDA, malondialdehyde; SOD, superoxide dismutase. Values are represented as mean ± SE (*p < 0.05).

FIGURE 3

Bar-dot plot panel of mRNA expression of pro-inflammatory cytokines following ChV and/or AFT exposure in the kidney tissue. (A) TNF-α mRNA, (B) IL-1β mRNA, and (C) IL-6 mRNA. AFTs, aflatoxins; ChV, Chlorella vulgaris; IL-1β; interleukin-1β, IL-6, interleukin-6; TNF-α, tumor necrosis factor-α. Values are represented as mean ± SE (*p < 0.05).

FIGURE 4

Molecular docking interactions of AFB1, AFB2, AFG1, and AFG2 with Japanese quails’ (A) extracellular superoxide dismutase (SOD1), (B) mitochondrial superoxide dismutase (SOD2), (C) glutathione peroxidase (GPx), (D) glutathione reductase (GR), (E) glutamate-cysteine ligase catalytic (GCLC) subunit, and (F) glutathione synthetase.

FIGURE 5

Molecular docking interactions of Chlorella vulgaris bioactive compounds with Japanese quails’ (A) interleukin-1 receptor accessory protein (IL1RAP), (B) interleukin-6 receptor subunit alpha (IL6RA), (C) tumor necrosis factor receptor superfamily member 1A (TNFRSF1A), and (D) tumor necrosis factor receptor-associated factor 1 (TRAF1).

FIGURE 6

Bar-dot plot panel of the impact of ChV supplementation on egg total AFT residue. AFTs, aflatoxins; ChV, Chlorella vulgaris. Values are represented as mean ± SE (*p < 0.05).

FIGURE 7

Clustering analysis of whole datasets after ChV and/or AFT exposure. (A) DSPC network of substantially distinct variables in the control and exposed groups. In the DSPC network, the nodes represent the measured variables, while the edges signify the correlation measures. Variables with the stronger correlation group cluster together and have wider edges between them. The blue lines display a negative correlation, while the red lines display a positive correlation with variables. (B) Heatmap and hierarchical clustering provide a visual summary of all the data. Each colored cell on the map represents a concentration value, and the rows and columns are made of different averages and treatment sets, respectively. Dark red has the highest value on the gradation scale, while blue has the lowest. (C) VIP score; the average concentrations of the measured variables are displayed for each study group in colored boxes on the right, and a colored scale from maximum (red) to least (blue) represents the contribution strength. AFTs, aflatoxins; ChV, Chlorella vulgaris; DSPC, debiased sparse partial correlation; VIP score, variable importance in projection score.

FIGURE 8

The protective effect of ChV against AFT-induced kidney injury is underpinned by molecular processes. AFTs, aflatoxins; ChV, Chlorella vulgaris; GCLC, glutamate-cysteine ligase catalytic subunit; GPx, glutathione peroxidase; GR, glutathione reductase; GSH synthetase, glutathione synthetase; IL1RAP, interleukin-1 receptor accessory protein; IL6RA, interleukin-6 receptor subunit alpha; MDA, malondialdehyde; ROS, reactive oxygen species; SOD, superoxide dismutase; TNFR, tumor necrosis factor receptor; TRAF1, tumor necrosis factor receptor-associated factor 1.