Transcriptional profiling of geniposide bioconversion into genipin during gardenia fructus extract fermentation by Lactobacillus (Lactiplantibacillus) plantarum SN13T.

Lactiplantibacillus plantarum SN13T is a probiotic plant-derived lactic acid bacterium that can grow in various medicinal plant extracts. In this study, we fermented an aqueous extract of gardenia fructus, the fruit of a medicinal plant, with SN13T, such that the bioactivity of the extract was potentiated after fermentation to suppress the release of inflammatory mediators, such as nitric oxide (NO), reactive oxygen species (ROS), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α), as well as downregulate inflammatory genes in lipopolysaccharides (LPS)-stimulated RAW 264.7 cells. This increased antioxidant and anti-inflammatory activity was mediated through bioconversion of the iridoid glycoside geniposide to its aglycone genipin via the supposed hydrolytic action of ß-glucosidases harbored by SN13T. In the complete genome of SN13T, ten putative genes encoding ß-glucosidases of glycosyl hydrolase (GH) family 1 organized among eight gene operons were identified. Transcriptional profiling revealed that two 6-phospho-ß-glucosidase genes, pbg9 and SN13T_1925, located adjacently in the gene operon SN13T_1923, were transcribed significantly more than the remaining genes during fermentation of the gardenia extract. This suggests the role of these ß-glucosidases in bioconversion of geniposide to genipin and the subsequent enhanced bioactivity of the gardenia fructus extract after fermentation with SN13T.

Role of Phenolic Acid Metabolism in Enhancing Bioactivity of Mentha Extract Fermented with Plant-Derived Lactobacillus plantarum SN13T.

Plant-derived lactic acid bacteria are major fermentation organisms that can grow in medicinal herb extracts enriched with phytochemicals like glycosides, phenolic acids, flavonoids, and tannins. Fermentation with strain-specific Lactobacilli harboring metabolic enzymes can increase the bioactivity and bioavailability of medicinal herbs. Fermentation of extracts of Artemisia princeps and Paeonia lactiflora has been previously found to increase their bioactivities. Therefore, this study explores the possibility of increasing the bioactivity of Mentha arvensis (Mentha) extract against lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells by fermenting with plant-derived probiotic strains Lactobacillus (Lact.) plantarum SN13T and Pediococcus (Ped.) pentosaceus LP28. As a result, fermentation with SN13T significantly increased the bioactivity of Mentha extract as compared to unfermented or LP28-fermented extracts. This higher bioactivity was associated with the metabolism of rosmarinic acid (RA) and caffeic acid (CA), the major bioactive phenolic acids reported in Mentha, along with the production of the metabolite dihydrocaffeic acid (DHCA). DHCA was found to be a more potent LPS-induced nitric oxide (NO) inhibitor than its precursor phenolic acids. The metabolism of RA to DHCA via CA could be mediated by the enzymes cinnamoyl ester hydrolase and hydroxycinnamate reductases, encoded by the ceh gene and the hcrRABC gene operon, respectively, which were identified in the complete genome sequence of Lact. plantarum SN13T but were absent in Ped. pentosaceus LP28. The genes hcrA, hcrB, and hcrC were significantly and time-dependently overexpressed in Lact. plantarum SN13T when grown in the Mentha extract, suggesting the role of phenolic acid metabolism in enhancing its bioactivity.

3-Phenyllactic acid generated in medicinal plant extracts fermented with plant-derived lactic acid bacteria inhibits the biofilm synthesis of Aggregatibacter actinomycetemcomitans.

In the present study, the effect of PLA on a periodontic pathogen, Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans), the biofilm, and virulence-related genes was investigated. We confirmed that two lactic acid bacteria (LAB) strains isolated from plant sources, Lactiplantibacillus plantarum MSC-C2 and Pediococcus pentosaceus K40, secrete PLA into the de Man, Rogosa & Sharpe (MRS) broth when supplemented with phenyl pyruvic acid (PPA) as a precursor to PLA. Moreover, PLA was generated in the fermentation broths of two medicinal plant extracts, Paeonia lactiflora Pall (PR) and Carthamus tinctorius (CT), when used by each LAB strain and each extract supplemented with PPA. We determined that the minimum inhibitory concentration (MIC) of PLA against A. actinomycetemcomitans was 20 mM. PLA significantly decreased biofilm formation and suppressed the transcription of pgA, ltxA, and cdtB genes, which encode the poly-N-acetylglucosamine (PGA) polysaccharide of biofilm matrix and exotoxins leukotoxin and cytolethal distending toxin (CDT), respectively. The PLA produced by the MSC-C2 and K40 strains was increased several times by the addition of PPA to the MRS broth. The anti-biofilm effect of the extracts from the fermentation broth was proportional to the increasing PLA concentration, while a cumulatively higher effect than that of PLA alone suggested a combinational effect of PLA and the other metabolites, such as lactic acid (LA). Among the two medicinal plants, PLA, produced after the addition of PPA, was higher in PR extract in case of both the LAB strains. PLA production by the MSC-C2 strain in the PR extract reached 4.8 ± 0.23 mM, which was obviously higher than that in the MRS broth (3.88 ± 0.12 mM) supplemented with 1 mg/ml PPA. The activity to inhibit biofilm formation in the fermented PR extract was clearly high. PLA formed in the fermented PR extract downregulated the dispersin B encoding the dspB gene together with pgA, ltxA, and cdtB. In conclusion, this study shows a promising activity of PLA against the A. actinomycetemcomitans biofilm and virulence genes. In addition, the combinational effect of PLA and the medicinal plant extract can be achieved by fermentation with a specific plant-derived LAB strain.

Anti-Oxidant and Anti-Inflammatory Substance Generated Newly in Paeoniae Radix Alba Extract Fermented with Plant-Derived Lactobacillus brevis 174A.

Fermentation of medicinal herbs can be a significant technique to obtain bioactive compounds. Paeoniae Radix (PR) used in the present study is a well-known herbal medicine that exhibits anti-inflammatory and immunomodulatory activity. The aim of this study is to explore the possibility that a bioactive compound is newly generated in PR extract by fermentation with a plant-derived lactic acid bacteria Lactobacillus brevis 174A. We determined the anti-inflammatory activities in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells. The PR extract fermented with Lactobacillus brevis 174A markedly increased the total phenolic content, decreased intracellular ROS levels, inhibited the release of nitric oxide (NO). It also suppressed inflammatory cytokines IL-6, TNF-ɑ, while simultaneously downregulating the gene expressions of iNOS, IL-6, TNF-ɑ, and IL-1ß compared to the unfermented PR extract. Furthermore, the bioactive compound newly generated from the fermentation was identified as pyrogallol. It inhibits the inflammatory responses in a dose-dependent manner suggesting that fermentation of the herbal extract used as a medium together with the plant-derived lactic acid bacterial strain may be a practical strategy to produce medicines and supplements for healthcare.

Rebamipide to Manage Stomatopyrosis in Oral Submucous Fibrosis.

INTRODUCTION: Oral submucous fibrosis (OSF) causes progressive debilitating symptoms, such as oral burning sensation (stomatopyrosis) and limited mouth opening. The standard of care (SOC) protocol includes habit cessation, intralesional steroid and hyaluronidase injections, and mouth opening exercises. The objective of the study was to evaluate efficacy of rebamipide in alleviating burning sensation of the oral mucosa in OSF in comparison with SOC intralesional steroid injections. MATERIALS AND METHODS: Twenty OSF patients were divided into two groups [rebamipide (100 mg TID for 21 days) and betamethasone (4 mg/mL biweekly for 4 weeks)] of 10 each by random sampling. Burning sensation was assessed every week for 1 month. Burning sensation scores were analyzed using repeated measures analysis of variance (ANOVA) and paired t-test. RESULTS: Change in burning sensation score was significant (p < 0.05) in the first four visits. However, score between the 4th and 5th visit was not statistically significant (p > 0.05). CONCLUSION: Our study has shown that rebamipide can be considered as an effective modality to manage burning sensation in patients suffering from OSF. CLINICAL SIGNIFICANCE: Considering stomatopyrosis and trismus as a major cause for inability to eat in OSF, use of newer adjunctive modalities, such as rebamipide will ease patients suffering and also encourage them to consume food.