Bioconversion of isoflavones during the fermentation of Samso-Eum with Lactobacillus strains

Lactic Acid Bacteria-Fermentable Cereal- and Pseudocereal-Based Beverages

Plant beverages are becoming more popular, and fermented cereal- or pseudocereal-based beverages are increasingly used as alternatives for fermented products made from cow milk. This review aimed to describe the basic components of cereal- or pseudocereal-based beverages and determine the feasibility of fermenting them with lactic acid bacteria (LAB) to obtain products with live and active LAB cells and increased dietary value. The technology used for obtaining cereal- or pseudocereal-based milk substitutes primarily involves the extraction of selected plant material, and the obtained beverages differ in their chemical composition and nutritional value (content of proteins, lipids, and carbohydrates, glycemic index, etc.) due to the chemical diversity of the cereal and pseudocereal raw materials and the operations used for their production. Beverages made from cereals or pseudocereals are an excellent matrix for the growth of LAB, and the lactic acid fermentation not only produces desirable changes in the flavor of fermented beverages and the biological availability of nutrients but also contributes to the formation of functional compounds (e.g., B vitamins).

Enhancement of neuroprotective activity of Sagunja-tang by fermentation with lactobacillus strains

BACKGROUND

Sagunja-tang (SGT) is widely used in traditional herbal medicine to treat immune system and gastrointestinal disorders and reportedly has protective effects against inflammation, cancer, and osteoporosis. In this study, we fermented SGT with different Latobacillus strains and investigated the change in phytochemical compositions in SGT and enhancement of it neuroprotective effects in SH-SY5Y human neuroblastoma.

METHODS

Marker components, including ginsenoside Rg₁, glycyrrhizin, liquiritin, liquiritigenin, atractylenolide I, atractylenolide II, atractylenolide III, and pachymic acid, in SGT, were qualitatively and quantitatively analyzed using high-performance liquid chromatography-diode array detection and liquid chromatography-mass spectrometry. SGT was fermented with eight different Lactobacillus strains to yield eight fermented SGTs (FSGTs). The conversion efficiencies of SGT marker components were determined in each FSGT. To detect the protective effect of SGT and FSGT, reactive oxygen species (ROS) assay and mitochondrial membrane potentials (MMPs) assay were performed in SH-SY5Y cells.

RESULTS

Compared with the other FSGTs, SGT166, i.e., SGT fermented with L. plantarum 166, had high conversion efficiency, as indicated by increased amounts of glycyrrhizin, liquiritigenin, and atractylenolides I-III. In SH-SY5Y cells, protection against cell death induced by H₂O₂ and etoposide was high using SGT166 and very low using SGT. Furthermore, ROS production and mitochondrial membrane potential disruption in SH-SY5Y cells were markedly suppressed by SGT166 treatment, which demonstrated that inhibition of ROS generation may be one of the neuroprotective mechanisms of SGT166.

CONCLUSIONS

This study demonstrated that fermentation of SGT with L. plantarum 166 enhanced suppression of oxidative stress and MMP loss. This enhanced neuroprotective effect was thought to be caused by the conversion of SGT phytochemicals by fermentation. SGT166 shows potential for treating neurological damage-related diseases.

Biotechnological methods for chalcone reduction using whole cells of Lactobacillus, Rhodococcus and Rhodotorula strains as a way to produce new derivatives

Microbial strains of the genera Dietzia, Micrococcus, Pseudomonas, Rhodococcus, Gordonia, Streptomyces, Pseudomonas, Bacillus, Penicillium, Rhodotorula and Lactobacillus were screened for the ability to convert chalcones. Synthesis of chalcones was performed by the Claisen-Schmidt reaction. There were three groups of chalcones obtained as the products, which included the derivatives containing 4-substituted chalcone, 2'-hydroxychalcone and 4'-methoxychalcone. The B ring of the chalcones was substituted in the para position with different groups, such as halide, hydroxyl, nitro, methyl, ethyl and ethoxy one. The structure-activity relationship of the tested chalcones in biotransformation processes was studied. It has been proven that Gram-positive bacterial strains Rhodococcus and Lactobacillus catalyzed reduction of C=C bond in the chalcones to give respective dihydrochalcones. The strain Rhodotorula rubra AM 82 transformed chalcones into dihydrochalcones and respective secondary alcohols. These results suggest that the probiotic strain of Lactobacillus can be used for biotransformations of chalcones, which has not been described before. The structure of new metabolites 14a and 15b were established as 4-ethoxy-4'-methoxydihydrochalcone and 3-(4-bromophenyl)-1-(4'-O-methylphenyl)-2-propan-1-ol, respectively, which was confirmed by (1)H NMR and (13)C NMR analysis.

Simultaneous determination of nine bioactive compounds in Yijin-tang via high-performance liquid chromatography and liquid chromatography-electrospray ionization-mass spectrometry

Background

Yijin-tang (YJ) has been used traditionally for the treatment of cardiovascular conditions, nausea, vomiting, gastroduodenal ulcers, and chronic gastritis. In this study, a simple and sensitive high-performance liquid chromatography (HPLC) method was developed for the quantitation of nine bioactive compounds in YJ: homogentisic acid, liquiritin, naringin, hesperidin, neohesperidin, liquiritigenin, glycyrrhizin, 6-gingerol, and pachymic acid.

Methods

Chromatographic separation of the analytes was achieved on an RS Tech C₁₈ column (4.6 mm × 250 mm, 5 μm) using a mobile phase composed of water containing 0.1% (v/v) trifluoroacetic acid (TFA) and acetonitrile with a gradient elution at a flow rate of 1.0 mL/min.

Results

Calibration curves for all analytes showed good linearity (R² ≥ 0.9995). Lower limits of detection and lower limits of quantification were in the ranges of 0.03–0.17 μg/mL and 0.09–0.43 μg/mL, respectively. Relative standard deviations (RSDs; %) for intra- and interday assays were < 3%. The recovery of components ranged from 98.09% to 103.78%, with RSDs (%) values ranging from 0.10% to 2.59%.

Conclusion

This validated HPLC method was applied to qualitative and quantitative analyses of nine bioactive compounds in YJ and fermented YJ, and may be a useful tool for the quality control of YJ.

Effect of fermented medicinal plants on growth performance, nutrient digestibility, fecal noxious gas emissions, and diarrhea score in weanling pigs

BACKGROUND

Antibiotics used as growth promoters in livestock have been banned in the European Union since 2006. Alternatives of antibiotics have focused on phytogenic plants, such as herbs and medicinal plants. No studies have evaluated the use of fermented medicinal plants (FMP) made up of Gynura procumbens, Rehmannia glutinosa and Scutellaria baicalensis in weanling pigs. Therefore, an experiment was conducted to determine the effects of FMP on growth performance, nutrient digestibility, fecal noxious gas emissions and diarrhea score in weanling pigs.

RESULTS

FMP supplementation increased (P < 0.05) average daily gain, average daily feed intake, gain:feed, apparent total tract digestibility of dry matter, nitrogen and gross energy compared with NC treatment, while a linear effect (P < 0.05) was observed on those criteria. Ammonia, total mercaptans and hydrogen sulfide concentrations were decreased (P < 0.05) by the supplementation of FMP compared with NC. Additionally, diarrhea score was lower (P < 0.05) by FMP addition compared with NC during days 0-7 and days 8-14.

CONCLUSION

These results suggested that FMP could be used as an alternative to antibiotics by enhancing growth performance and nutrient digestibility, and decreasing fecal noxious gas emission and early diarrhea score of weanling pigs.

Isoflavone metabolism by a collection of lactic acid bacteria and bifidobacteria with biotechnological interest

Almost all soy isoflavones exist as glycosides, daidzin, genistin, and glycitin. We analyzed the capacity of 92 strains of lactic acid bacteria (LAB) and bifidobacteria with biotechnological interest to process the glycosylated isoflavones daidzin, genistin, and glycitin in their more bioavailable aglycones and their metabolites as dihydrodaidzein (DHD), O-desmethylangolensin, and equol. Representative strains of the four genera studied Lactobacillus, Enterococcus, Lactococcus, and Bifidobacterium were able to produce daidzein, genistein, and glycitein, with the exception of the lactobacilli, which did not produced glycitein in soy extracts. The production of the aglycone isoflavones could be correlated with the β-glucosidase activity of the strains. The isoflavone metabolism is limited to the glycoside hydrolysis in the most of these strains. Moreover, Enterococcus faecalis INIA P333 and Lactobacillus rhamnosus INIA P540 were able to transform daidzein in DHD. LAB and bifidobacteria studied in the present work have a great potential in the metabolism of isoflavones and could be selected for the development of functional fermented soy foods.

Neuroprotective effect of the fermented Gumiganghwal-tang

Gumiganghwal-tang (GT) is a traditional herbal prescription widely used to treat inflammatory diseases in Asia. In this study, we evaluated neuroprotective effect and acetylcholinesterase (AChE) inhibitory activity of GT and compared with fermented GT (FGT). In order to better understand the neuroprotective mechanism, intracellular reactive oxygen species (ROS) production was investigated and high-performance liquid chromatography with diode-array detection (HPLC-DAD) analysis of contents of GT and FGT were conducted. As a result, FGT showed more potent protective effect against glutamate-induced HT22 cell death than GT and inhibited AChE activity. The neuroprotective effect of FGT is associated with inhibition of ROS production. The HPLC-DAD analytical results indicated that FGT contains higher content of bergapten and atractylenolide III than that of GT. In conclusion, FGT have neuroprotective effect and AChE inhibition, and may be useful source for treatment of neurodegenerative disease.

β-Glucosidase activities of lactic acid bacteria: mechanisms, impact on fermented food and human health

Through the hydrolysis of plant metabolite glucoconjugates, β-glucosidase activities of lactic acid bacteria (LAB) make a significant contribution to the dietary and sensory attributes of fermented food. Deglucosylation can release attractive flavour compounds from glucosylated precursors and increases the bioavailability of health-promoting plant metabolites as well as that of dietary toxins. This review brings the current literature on LAB β-glucosidases into context by providing an overview of the nutritional implications of LAB β-glucosidase activities. Based on biochemical and genomic information, the mechanisms that are currently considered to be critical for the hydrolysis of β-glucosides by intestinal and food-fermenting LAB will also be reviewed.