Synergistic Effects of Licorice Root and Walnut Leaf Extracts on Gastrointestinal Candidiasis, Inflammation and Gut Microbiota Composition in Mice.

Candida albicans is an opportunistic pathogen that causes gastrointestinal (GI) candidiasis closely associated with intestinal inflammation and dysbiosis. Drug resistance, side effects of available antifungal agents, and the high recurrence of candidiasis highlight the need for new treatments. We investigated the effects of hydroethanolic extracts of licorice root (LRE) and walnut leaf (WLE) on GI colonization by C. albicans, colon inflammation, and gut microbiota composition in C57BL/6 female mice. Oral administration of LRE and WLE alone or in combination once daily for 12 days before C. albicans infection and then for 5 days after infection significantly reduced the level of C. albicans in the feces of gastrointestinal infected mice as well as colonization of the GI tract, both extracts showing robust antifungal activity. Although total bacterial content was unaffected by the extracts (individually or combined), the abundance of protective bacteria, such as Bifidobacterium spp. and Faecalibacterium prausnitzii, increased with the combination, in contrast to that of certain pathobiont bacteria, which decreased. Interestingly, the combination induced a more robust decrease in the expression of proinflammatory genes than either extract alone. The anti-inflammatory activity of the combination was further supported by the reciprocal increase in the expression of anti-inflammatory cytokines and the significant decrease in enzymes involved in the synthesis of proinflammatory eicosanoids and oxidative stress. These findings suggest that LRE and WLE have synergistic effects and that the LRE/WLE combination could be a good candidate for limiting GI candidiasis and associated inflammation, likely by modulating the composition of the gut microbiota. IMPORTANCE The adverse effects and emergence of resistance of currently available antifungals and the high recurrence of candidiasis prompt the need for alternative and complementary strategies. We demonstrated that oral administration of hydroethanolic extracts of licorice root (LRE) and walnut leaf (WLE) separately or in combination significantly reduced the colonization of the gastrointestinal (GI) tract by C. albicans, highlighting a robust antifungal activity of these plant extracts. Interestingly, our data indicate a correlation between LRE and WLE consumption, in particular the combination, and a shift within the gut microbiome toward a protective profile, a decrease in colonic inflammation and prooxidant enzymes, suggesting a synergistic effect. This study highlights the significant prebiotic potential of the LRE/WLE combination and suggests that the health benefits are due, at least in part, to their ability to modulate the gut microbiota, reduce inflammation and oxidative stress, and protect against opportunistic infection.

The Use of Natural Agents to Counteract Telomere Shortening: Effects of a Multi-Component Extract of Astragalus mongholicus Bunge and Danazol.

A link between telomere shortening and oxidative stress was found in aging people and patients with cancer or inflammatory diseases. Extracts of Astragalus spp. are known to stimulate telomerase activity, thereby compensating telomere shortening. We characterized a multi-component hydroethanolic root extract (HRE) of Astragalus mongholicus Bunge and assessed its effects on telomeres compared to those of danazol. Astragalosides I to IV, flavonoids, amino acids and sugars were detected in the HRE. Samples of peripheral blood lymphocytes with short telomeres from 18 healthy donors (mean age 63.5 years; range 3286 years) were exposed to a single dose of 1 µg/mL HRE or danazol for three days. Telomere length and telomerase expression were then measured. Significant elongation of telomeres associated to a less toxicity was observed in lymphocytes from 13/18 donors following HRE treatment (0.54 kb (0.15-2.06 kb)) and in those from 9/18 donors after danazol treatment (0.95 kb (0.06-2.06 kb)). The rate of cells with short telomeres (<3 kb) decreased in lymphocytes from all donors after exposure to either HRE or danazol, telomere elongation being telomerase-dependent. These findings suggest that the HRE could be used for the management of age-related diseases.

Correction: Benefits of the ipowder® extraction process applied to Melissa officinalis L.: improvement of antioxidant activity and in vitro gastro-intestinal release profile of rosmarinic acid.

Correction for 'Benefits of the ipowder® extraction process applied to Melissa officinalis L.: improvement of antioxidant activity and in vitro gastro-intestinal release profile of rosmarinic acid' by Valérie Bardot et al., Food Funct., 2020, DOI: 10.1039/c9fo01144g.

Benefits of the ipowder® extraction process applied to Melissa officinalis L.: improvement of antioxidant activity and in vitro gastro-intestinal release profile of rosmarinic acid.

The objective of this study was to evaluate the benefits of a new extraction process, the ipowder® technology, applied to Melissa officinalis L. Compared to M. officinalis ground dry leaves, the ipowder® had a similar phytochemical fingerprint but contained twice the concentration of rosmarinic acid (by HPTLC and HPLC) and had a two-fold greater antioxidant activity (DPPH* method). In vitro digestion experiments (TIM-1 model) showed better availability of rosmarinic acid for intestinal absorption with the ipowder® than with ground dry leaves, manifested by a three-fold reduction in the quantity of ingested product needed for delivery of the same amount of rosmarinic acid into the upper gastro-intestinal tract. This study shows that the ipowder® technology preserves all the original plant compounds intact while making some active ingredients more accessible and available to exert their effects. To obtain a given effect, the amount of ipowder® extract to ingest will therefore be lower; a reduction in the daily dosage will be more convenient for the patient and will improve patient compliance with supplementation.

Reduction of acute mild stress corticosterone response and changes in stress-responsive gene expression in male Balb/c mice after repeated administration of a Rhodiola rosea L. root extract.

Rhodiola rosea L. (R. rosea) is an adaptogenic plant increasing body resistance to stress. Its efficacy has been evidenced mainly in chronic stress models, data concerning its effect in acute stress and underlying mechanisms being scarce. The objective was to investigate the effect of repeated doses of a R. rosea hydroethanolic root extract (HRE) on hypothalamic pituitary adrenal response in a murine model of acute mild stress and also the mechanisms involved. Stress response was measured in Balb/c mice having received by gavage HRE (5 g/kg) or vehicle daily for 2 weeks before being submitted to an acute mild stress protocol (open-field test then elevated plus maze). Corticosterone was measured in plasma from mandibular vein blood drawn before and 30, 60, and 90 min after initiation of the stress protocol. Mice were sacrificed at 90 min, and the hippocampus, prefrontal cortex, and amygdala were excised for high-frequency RT-PCR gene expression analysis. At 30 min after acute mild stress induction, corticosterone level in mice having received the HRE was lower than in control mice and comparable to that in nonstressed mice in the HRE group. HRE administration induced brain structure-dependent changes in expression of several stress-responsive genes implicated in neuronal structure, HPA axis activation, and circadian rhythm. In the acute mild stress model used, R. rosea HRE decreased corticosterone level and increased expression of stress-responsive genes, especially in the hippocampus and prefrontal cortex. These findings suggest that R. rosea HRE could be of value for modulating reactivity to acute mild stress.

Identification, library synthesis and anti-vibriosis activity of 2-benzyl-4-chlorophenol from cultures of the marine bacterium Shewanella halifaxensis.

Summer Gut Syndrome (SGS) is caused by various Vibrio bacterial species and can have negative effects on aquaculture farms worldwide. In New Zealand, SGS is caused by Vibrio harveyii infecting King Salmon (Oncorhynchus tshawytscha). To find leads for the prevention of SGS, we screened the inhibitory effects of 16 strains of Shewanella upon V. harveyii growth in competitive solid phase cultures. The detailed investigation of Shewanella halifaxensis IRL548 revealed 2-benzyl-4-chlorophenol (1), a known, commercially available antibacterial agent, as the major bioactive component. Synthesis of a small library of congeners to confirm the natural product identity and to provide a structure-activity relationship for the observed activity was also completed. Compound 1 exhibits moderate activity against two pathogenic microorganisms.