Antifungal Effect of Camellia Seed Cake Extract on Aspergillus flavus

Abstract

ABSTRACT Aspergillus flavus is a well-known, widespread fungus that contaminates a great number of crops used for human and animal consumption, but previous study showed that camellia seed cake was not susceptible to A. flavus. This study was designed to evaluate the antifungal effect of the active substance in camellia seed cake on the growth and production of aflatoxins of A. flavus. Eighty percent methanol extracts of camellia seed cake showed greater activity than that of 80% ethanol, ethyl acetate, and pure water against A. flavus. The filtrate from the 80% methanol extract was extracted with ethyl acetate and saturated n-butanol; among the extracts, the n-butanol phase exhibited strong inhibitory activity against A. flavus. The inhibitory zone diameter increased from 15.25 mm at 25 mg/mL concentration up to 22.00 mm at 100 mg/mL concentration. The mycelial dry weight was reduced significantly from 0.16 g at 25 mg/mL to 0.11 g at 100 mg/mL, whereas the aqueous and ethyl acetate phases exhibited weak antifungal activity and no activity, respectively. In addition, the n-Butanol phase inhibited the production of aflatoxin B1 effectively, caused mycelia deformity, and reduced the production of conidia. n-Butanol extract of camellia seed cake exhibited apparent antagonistic effect on the growth and aflatoxin production of A. flavus. The concentration of 100 mg/mL worked best. This study provides a scientific basis for further study of its inhibiting mechanism. HIGHLIGHTS