acta satech Journal of the Life & Physical Sciences Babcock

Preliminary screening of aqueous extract of Piper guineense against aflatoxin biosynthesis in Aspergillus flavus and A. parvisclerotigenus
Ezekiel, C. N.1, Sulyok, M.2, Anokwuru, C. P.3,4, Bamidele M.W. Amos-Tautua5,6, Oni, O. E.7, Anyasor, G.N.8, Obonyo, M.A.9 & Krska, R.2
1Department of Microbiology, Babcock University, Ilishan Remo, Ogun State, Nigeria. 2Center for Analytical Chemistry, Department of Agrobiotechnology (IFA-Tulln), University of Natural Resources and Life Sciences Vienna (BOKU), Konrad Lorenzstr. 20, A-3430, Tulln, Austria. 3Department of Basic Sciences, Babcock University, Ilishan Remo, Ogun State, Nigeria. 4Department of Chemistry, University of Venda, South Africa. 5Department of Chemistry, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria. 6Department of Applied Chemistry, University of Johannesburg, Doornfontein Campus, Doornfontein, Johannesburg, South Africa. 7Department of Microbial Ecophysiology, Faculty of Biology/Chemistry, University of Bremen, Bremen, Germany. 8Department of Biochemistry, Benjamin S. Carson (Snr.) College of Medicine, Babcock University, Ilishan Remo, Ogun State, Nigeria. 9Department of Biochemistry & Molecular Biology, Egerton University, P.O. Box 536-20115 Egerton, Kenya.
April, 2018

ABSTRACT
Food contamination by aflatoxigenic Aspergillus and consequent production of aflatoxins remain a significant threat to food safety. This has led to the continual search for plants with antifungal and anti-mycotoxigenic potencies for controlling moulds in food commodities. Aqueous extract of Piper guineense (Ashanti pepper, AP) was evaluated for antioxidant activity and inhibitory potential against growth and aflatoxin production in nine strains of aflatoxigenic Aspergillus [A. flavus (n = 4) and A. parvisclerotigenus (n = 5)] grown on neutral red desiccated coconut agar (NRDCA) for 5 days. Liquid chromatography tandem mass spectrometric analysis of 3 mm agar plugs from the inoculated AP-amended NRDCA treatments showed variable levels of aflatoxin inhibition. The 0.5% (v/v) AP extract inhibited AFB1 in A. flavus by 91.199.7%, and by 57.895.6% in A. parvisclerotigenus. Inhibition of the different types of aflatoxins correlated significantly (AFB1/AFG1: r = 0.87, p = 0.003; AFB1/AFM1: r = 0.94, p = 0.0001; AFG1/AFM1: r = 0.86, p = 0.005). However, there was no inhibition of fungal growth at all tested concentrations of the extract though the antioxidant levels of the spice were appreciably high. This study reveals the suppressive effect of P. guineense aqueous extract on aflatoxin biosynthesis.
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