Abstract
Microbial fermentation of plant material alters the composition of volatile and non-volatile plant natural products. We investigated the antioxidant, anticancer, and antiviral properties of extracts of defatted soybean meal fermented with
Aspergillus fumigatus F-993
or
A. awamori FB-133
using
in vitro
methods. Gas chromatography–mass spectrometry analysis of soybean meal fermented with
A. awamori FB-133
and
A. fumigatus F-993
identified 26 compounds with 11,14-octadecadienoic acid and methyl ester (63.63%) and 31 compounds with butylated hydroxytoluene (66.83%) and δ-myrcene (11.43%) as main constituents, respectively. The antioxidant activities of DSM extract were 3.362 ± 0.05 and 2.11 ± 0.02 mmol TE/mL, FDSM treated with
A. awamori FB-133
were 4.763 ± 0.05 and 3.795 ± 0.03 mmol TE/mL and FDSM treated with
A. fumigatus F-993
were 4.331 ± 0.04 and 3.971 ± 0.02 mmol TE/mL as determined by ABTS and FRAP assays, respectively. Both fermented extracts had better antioxidant activity than the unfermented extract as shown by multiple antioxidant activity assays. The concentration of fermented extracts required for 50% inhibition of cell viability was significantly lower than that of the unfermented extract when tested against the human liver cancer cell line HepG2 as shown by cell viability assays, indicating strong anticancer activity. The IC
50
values for DSM, FDSM with
A. fumigatusF-993
and FDSM with
A. awamori FB-133
were27, 16.88 and 8.60 μg/mL, respectively. The extract of FDSM with
A. awamori FB-133
showed the strongest anticancer activity, compared to DSM and FDSM with
A. FumigatusF-993
extracts. Fermented extracts also reduced hepatitis A virus titres to a greater extent than unfermented extracts, thus showing strong antiviral property. Hepatitis A virus titres were reduced by 2.66 and 3 log
10
/0.1 mL by FDSM with
A. fumigatusF-993
and FDSM by
A.awamori FB-133
, respectively, compared to DSM (5.50 log
10
/0.1 mL). Thus, the fermentation of soybean meal with
A. fumigatusF-993
or
A. awamori FB-133
improves the therapeutic effect of soybean extracts, which can be used in traditional medicine.