A comparative study on flavour components and therapeutic properties of unfermented and fermented defatted soybean meal extract

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 IC50 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 log10/0.1 mL by FDSM with A. fumigatusF-993 and FDSM by A.awamori FB-133, respectively, compared to DSM (5.50 log10/0.1 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.

The ameliorative effect of Aspergillus awamori on aflatoxin B1-induced hepatic damage in rabbits

This study was conducted to investigate the effect of dietary supplementation of Aspergillus awamori on aflatoxin B1 (AFB1)-induced liver damage in rabbits. Administration of AFB1 (0.3 mg/kg diet) led to a significant reduction in body weight, body weight gain, total feed intake, total serum proteins, albumin, high density lipoprotein-cholesterol, phagocytic activity, phagocytic index, and the antioxidant enzyme, glutathione peroxidase (GPx). Moreover, AFB1 administration was associated with a significant increase in feed conversion ratio, lipid peroxidation and serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, lactate dehydrogenase and total bilirubin. In addition, livers of AFB1-supplemented animals showed fatty degeneration with vacuolisation, focal areas of necrosis, mononuclear cells infiltration hyperplasia of bile ducts and sinusoids. A significant increase in the hepatic expression of the biotransformation gene (Cyp3A6), stress-sensitive genes (HO1 and SOD1), and inflammation-related genes (IL6, TNFa, NF-kB, and Cox2) was also observed. Supplementation of the diets with 0.05, 0.1 or 0.15% A. awamori ameliorated all AFB1 deleterious effects with the best improvement observed at the lowest concentration. This is the first investigation to report that supplementation of rabbit diets with A. awamori has an ameliorative effect against AFB1-induced liver damage possibly through preventing hepatic oxidative stress, promoting the antioxidant defence systems, and inhibiting expression of Cyp3A6, HO1, SOD1, IL6, TNFa, NF-kB, and Cox2. Therefore, A. awamori could be used as a potential preventive or therapeutic agent for aflatoxicosis.