Etude de l’effet antimycotoxinogène et antihépatotoxicose des extraits d’une plante utilisée dans la thérapie traditionnelle.
Kacem Chaouche, N.
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This work deals with the antimycotoxinogenesis and antihepatotoxicosis study of Lycium halimifolium Mill. Two fungal isolates were obtained from the peanut kernels, including a single isolate with similar characteristics to the genus Aspergillus sp. has been selected. Molecular identification confirmed that the selected isolate was an Aspergillus flavus registered under accession code (gi | 146746162 | EF409803.1) with a similarity of 99%. The preliminary evaluation of the composition of Lycium halimifoliumMill leaves revealed the presence of several chemical groups, the alkaloids, the terpenes and the saponosides. This latter was confirmed by a quantitative analysis. The obtained results showed that ACT and BUT fractions of Lycium halimifoliumMill leaves showed considerable polyphenol contents estimated at 61.66 ± 0.042 and 60.21 ± 0.102 μg EAG / mg PS, respectively. Whereas, those of the flavonoids also showed interesting values estimated at 25.18 ± 0.014 for ACT and 17.79 ± 0.015 μg EQ / mg PS for BUT. In contrast, low tannin levels were obtained and estimated at 5.872 ± 0.053 (ACT) and 7.058 ± 0.013 μg EC / mg PS (BUT). Chromatographic identification of the ACT fraction allowed to characterize four phenolic acids: protocatechic acid (19.29%), gallic acid (0.499%), ρ coumaric acid (0.386%), syringic acid (0.142 %) and a flavonoid (rutin) (12.58%). While the BUT fraction contains three phenolic acids: protocatechic acid (20.32%), syringic acid (0.236%), and coumaric acid (0.124%), and a flavonoid (rutin) (2.098%). It has been reported that protocatechic acid, gallic acid and syringic acid are identified for the first time in the present work on Lycium halimifolium Mill leaves. The antifungal activity allowed to estimate the MIC and CFS of the BUT fraction at 312 μg / ml and 625 μg / ml for the ACT fraction. The antimycotoxinogenic activity of Lycium halimifolium Mill showed an inhibition of aflatoxin B1 secreted by the BUT fraction estimated at 96.83%, and a percentage of inhibition equal to 94.99% was found by the ACT fraction. This activity was correlated with the percentage of reduction in mycelial biomass with a biomass inhibition rate of 56.53 ± 2.74% in the presence of ACT fraction and 65.22 ± 0.10% in the presence of BUT fraction. The Evaluation of antioxidant activity of the two fractions showed that the BUT fraction was more active than ACT fraction. The Antibacterial activity revealed that the BUT fraction had a positive effect on E. coli and S. aureus. Finally, the study of the antihepatotoxicity effect of the two fractions of Lycium halimifolium Mill leaves, showed that the mice treated with ACT and BUT experienced a normalization of the rates of TGO, TGP, PAL, as well as the standardization of the parameters of the oxidative stress. The histological study showed that both fractions preserved the hepatocytes against the oxidative lesions and thus played a protective role against oxidative stress against the histopathological changes produced by aflatoxin B1. This work is the first to have exhibited the antimycotoxinogenic activity and antihepatotoxicosis of Lycium halimifoliumMill leaves.
- Doctorat (Biochimie)