2018 Volume 68 Issue 1 Pages 19-25
We investigated the production of fungal metabolites as a biological response to Kampo medicines by incubating the filamentous fungus Emericella nidulans IFM 60678 with Kampo medicines and analyzing the culture extracts by HPLC. E. nidulans IFM 60678 was found to produce sterigmatocystin (ST) upon incubation with Shakuyaku-kanzo-to. Further investigation revealed that the production of ST is stimulated by Peony root (Paeonia lactiflora), a component of Shakuyaku-kanzo-to. Peony root extract induced ST production in 21 of 27 (78%) non-ST-producing E. nidulans strains but did not induce the production of ST or aflatoxins in 22 non-ST-producing Aspergillus flavus strains. This result suggested that Peony root extract may induce ST production by E. nidulans specifically. Several other crude drugs, and especially Alisma tuber (Alisma orientale), Bupleurum root (Bupleurum falcatum), Japanese Angelica root (Angelica acutiloba), and Pinellia tuber (Pinellia ternata), potently induced ST production. Our unique and simple method might help identify new natural products and new regulatory strategies applicable to mycotoxin production.
