Artichoke Leaf Extract-Mediated Neuroprotection against Effects of Aflatoxin in Male Rats

Abstract

Attenuation of adverse effects of aflatoxin (AFB₁) in brains of B₁ rats by extracts of leaves of artichoke was studied. The active ingredients in extracts of leaves of artichoke, Cynara scolymus L., were determined by HPLC analysis. In the 42-day experiment, rats were exposed to either sterile water, 4% DMSO, 100 mg artichoke leaf extract/kg body mass, 72 μg aflatoxin B₁/kg body mass, or AFB₁ plus artichoke leaf extract. Neurotoxicity of AFB₁ was determined by an increase in profile of lipids, augmentation of plasmatic glucose and concentrations of insulin, oxidative stress, increased activities of cholinergic enzymes, and a decrease in activities of several antioxidant enzymes and pathological changes in brain tissue. Extracts of artichoke leaf significantly reduced adverse effects caused by AFB₁, rescuing most of the parameters to values similar to unexposed controls, which demonstrated that adverse, neurotoxic effects caused by aflatoxin B₁ could be significantly reduced by simultaneous dietary supplementation with artichoke leaf extract, which itself is not toxic.

Figure 1

(a) HPLC chromatogram of aqueous extract of the artichoke (Cynara scolymus L.) leaf extract capsule and (b) list of the components of the artichoke capsule and their concentrations.

Figure 2

Mean ± SD of total lipids (a), cholesterol (b), triglycerides (c), HDL (d), LDL (e), and VLDL (f) in plasma of male rats treated with AFB1, ALE, and their combination for 42 days. Abbreviations: control: animals treated with water; DMSO: animals treated with DMSO (solvent); ALE: animals treated with artichoke leaves extract (100 mg/kg body weight); AFB1: animals treated with Aflatoxin B1 (72 μg/kg body weight); ALE+AFB1: animals treated with a combination of artichoke extract and aflatoxin B1; LDL: low-density lipoprotein; VLDL: very low-density lipoprotein; HDL: high-density lipoprotein. The same letter (A, B, C, D, and E) denote no significant difference among experimental groups (p < 0.05; n = 5; LSD, ANOVA test).

Figure 3

Mean ± SD of glucose (a) and insulin (b) concentration, HOMA-IR (c), and HOMA-B (d) index in plasma of male rats treated with AFB1, ALE, and their combination for 42 days. Abbreviations: HOMA-IR: homeostatic model assessment for insulin resistance; HOMA-B: homeostatic model assessment for beta cells; for other explanations, see Figure 1.

Figure 4

Mean ± SD concentration of TNFα (a), IDO (b), and TIMP3 (c) in the brain of male rats treated with AFB1, ALE, and their combination for 42 days. Abbreviations: TNFα: tumor necrosis factors α; IDO: indoleamine-pyrrole 2,3-dioxygenase; TIMP3: tissue inhibitor metallopeptidase; for other explanations, see Figure 1.

Figure 5

Mean ± SD concentration of TBARS (a), activity of XO (b), and concentration of UA (c) in the brain of male rats treated with AFB1, ALE, and their combination for 42 days. Abbreviations: TBARS: thiobarbituric acid reactive substances; XO: xanthine oxidase; UA: uric acid; for other explanations, see Figure 1.

Figure 6

Mean ± SD concentration of GSH (a) and activity of SOD (b), GST (c), and GPx in the brain of male rats treated with AFB1, ALE, and their combination for 42 days. Abbreviations: GSH: glutathione reduced form; SOD: superoxide dismutase; GST: glutathione S-transferase; GPx: glutathione peroxidase; for other explanations, see Figure 1.

Figure 7

Mean ± SD activity of AChE (a) and MAO (b) and concentration of NO (c) and urea (d) in the brain of male rats treated with AFB1, ALE, and their combination for 42 days. Abbreviations: AChE: acetylcholinesterase; MAO: monoamine oxidase; NO: nitric oxide; for other explanations, see Figure 1.

Figure 8

Principal component analysis (PCA) to evaluate similarities among all the parameters measured in the brain or plasma of male rats treated with AFB1 (aflatoxin B1-72 μg/kg body weight), ALE (artichoke leaves extract -100 mg/kg body weight), and their combination for 42 days. (a) PCA analysis of variables. (b) PCA analysis of cases. Abbreviations: see Figures 1–6.

Figure 9

Representative H&E-stained brain samples of male rats from the control group, ALE group (artichoke leaves extract -100 mg/kg body weight), AFB1 group (aflatoxin B1 -72 μg/kg body weight), and ALE+AFB1 group (artichoke leaves extract -100 mg/kg body weight+aflatoxin B1-72 μg/kg body weight). Abbreviations: CA1, 2, 3: cornu ammonis 1, 2, 3; DG: dentate gyrus; Sp: stratum pyramidalis; Sr: stratum radiatum; So: stratum oriens; for other explanations, see Figure 1.