Protection of maize by storage fungi and aflatoxin production using botanicals

215-221In the present study the effect of alcoholic, hydroalcoholic and aqueous extracts of Lawsonia inermis Linn. (Henna), Murraya paniculata (Linn.) Jack (Orange jessmine) and Psidium guajava Linn. (Common guava) leaves on Aspergillus flavus and A. parasiticus growth and aflatoxin production and on growth in corn under storage conditions was studied. The extract that most effectively inhibited growth as well as aflatoxin production during in vitro experiments was found to be aqueous leaf extract of L. inermis and M. paniculata. The MIC obtained with L. inermis leaf aqueous extract was 5 mg/mL and 10 mg/mL of culture medium for <i style="mso-bidi-font-style: normal">A. flavus and A. parasiticus, respectively. Whereas it was 8 mg/mL and 9 mg/mL for <i style="mso-bidi-font-style: normal">A. flavus and A. parasiticus, respectively with M. paniculata leaf aqueous extract. A combination of both extracts was also assayed for the MIC, inhibition of aflatoxin production and applied to maize grains for prevention of infection and aflatoxin synthesis in storage conditions. The MIC obtained for combination of both extracts was 4 mg/mL for both test fungi. Aflatoxins were assayed qualitatively and quantitatively by TLC under 365 nm. The MIC of both extracts was found higher (>30 mg/mL) when examined in maize grains. However, concentrations lower than the MIC drastically inhibited the production of aflatoxins in culture medium and also in maize grains. Half of the MIC inhibited 99% of aflatoxins.