Pentagalloyl glucose and gallotannins from mangifera Indica L. seed kernel extract as a promising antifungal feed additive, in vitro, and in silico studies

Recently, the valorization of agro-industrial wastes through their exploration of their bioactive compounds has become a necessary trend to maximize their applications in various production sectors, particularly animal feeding. In the study, mango seed kernels were used as agro-industrial wastes to extract gallotannins fraction (GF) and pentagalloyl glucose (PGG). The GF and PGG were mixed with poultry feeds to investigate their potential ability to control Aspergillus flavus ( A. flavus ) growth and inhibit its production of aflatoxins (AFs). Ketoconazole was used as an antifungal standard. GF and PGG combat the growth of A. flavus , with minimum inhibition concentration (MIC) of 21.7 +/- 1.7 and 20 +/- 0 mg/mL, respectively. Moreover, GF and PGG showed promising results in preventing the production of AFs (AFB1, AFB2, AFG1, and AFG2) at 5 and 10 mg/100-g feed. Furthermore, to explain the mode of action of PGG as an antifungal agent, a molecular docking study has been performed against Type 1 Polyketide Synthase (PKS), which is found in many toxigenic Aspergillus species and has a highly active Acyl Carrier Protein (ACP) domain that is implicated in thiol ester-bound intermediates involved in fungal polyketides, fatty acids, and other non-ribosomal peptide formation, which are highly implicated in the construction of aflatoxin biosynthesis. The promising results prompt us to use mango seed extract as a cheap source of gallotannin components as a safe feed additive for reducing fungal and mycotoxin contamination in animal feeds.