Bioactive composition, antimicrobial activities and the influence of Agrocybe aegerita (Brig.) Sing on certain quorum-sensing-regulated functions and biofilm formation by Pseudomonas aeruginosa

Ethnomycological Investigation in Serbia: Astonishing Realm of Mycomedicines and Mycofood

This study aims to fill the gaps in ethnomycological knowledge in Serbia by identifying various fungal species that have been used due to their medicinal or nutritional properties. Ethnomycological information was gathered using semi-structured interviews with participants from different mycological associations in Serbia. A total of 62 participants were involved in this study. Eighty-five species belonging to 28 families were identified. All of the reported fungal species were pointed out as edible, and only 15 of them were declared as medicinal. The family Boletaceae was represented by the highest number of species, followed by Russulaceae, Agaricaceae and Polyporaceae. We also performed detailed analysis of the literature in order to provide scientific evidence for the recorded medicinal use of fungi in Serbia. The male participants reported a higher level of ethnomycological knowledge compared to women, whereas the highest number of used fungi species was mentioned by participants within the age group of 61–80 years. In addition to preserving ethnomycological knowledge in Serbia, this study can present a good starting point for further pharmacological investigations of fungi.

Quorum sensing in food spoilage and natural-based strategies for its inhibition

Food can harbor a variety of microorganisms including spoilage and pathogenic bacteria. Many bacterial processes, including production of degrading enzymes, virulence factors, and biofilm formation are known to depend on cell density through a process called quorum sensing (QS), in which cells communicate by synthesizing, detecting and reacting to small diffusible signaling molecules - autoinducers (AI). The disruption of QS could decisively contribute to control the expression of many harmful bacterial phenotypes. Several quorum sensing inhibitors (QSI) have been extensively studied, being many of them of natural origin. This review provides an analysis on the role of QS in food spoilage and biofilm formation within the food industry. QSI from natural sources are also reviewed towards their putative future applications to prolong shelf life of food products and decrease foodborne pathogenicity.

Fungal Quorum-Sensing Molecules and Inhibitors with Potential Antifungal Activity: A Review

The theory of persisting independent and isolated regarding microorganisms is no longer accepted. To survive and reproduce they have developed several communication platforms within the cells which facilitates them to adapt the surrounding environmental changes. This cell-to-cell communication is termed as quorum sensing; it relies upon the cell density and can stimulate several traits of microbes including biofilm formation, competence, and virulence factors secretion. Initially, this sophisticated mode of communication was discovered in bacteria; later, it was also confirmed in eukaryotes (fungi). As a consequence, many quorum-sensing molecules and inhibitors have been identified and characterized in various fungal species. In this review article, we will primarily focus on fungal quorum-sensing molecules and the production of inhibitors from fungal species with potential applications for combating fungal infections.

Polysaccharides with Antioxidative and Antiaging Activities from Enzymatic-Extractable Mycelium by Agrocybe aegerita (Brig.) Sing

This study aimed to investigate the antioxidant, antiaging, and organ protective effects of the water-extractable mycelium polysaccharides (MPS) and enzymic-extractable mycelium polysaccharides (En-MPS) by Agrocybe aegerita (Brig.) Sing in D-galactose-induced (D-gal-induced) aging mice. In in vitro assays, the En-MPS demonstrated stronger antioxidant activities in dose-dependent manners. The mice experiments revealed that both En-MPS and MPS had potential effects on antioxidation, antiaging, and organ protection mainly by improving the antioxidant enzyme activities, decreasing the lipid peroxidation, and remitting the lipid metabolism. Furthermore, chemical composition and monosaccharide composition of polysaccharides were also measured, and the results indicated that differences in biological activity of MPS and En-MPS samples showed a significant correlation to their purity. The findings demonstrated that the polysaccharides by A. aegerita (Brig.) Sing could be exploited as natural and functional foods for the prevention and alleviation of aging and its complications.

Chemical, nutritive composition and a wide range of bioactive properties of honey mushroom Armillaria mellea (Vahl: Fr.) Kummer

A. mellea fruiting bodies collected from nature were chemically characterized and shown to be rich in carbohydrates (81.25 g per 100 g dw), ash, fat and proteins (8.84 g per 100 g dw, 1.97 g per 100 g dw and 1.81 g per 100 g dw, respectively). Mannitol was the main free sugar while malic acid was the most abundant organic acid. δ-Tocopherol was the dominant form of tocopherols with 42.41 μg per 100 g dw. Polyunsaturated fatty acids were predominant, followed by saturated and monounsaturated fatty acids. A methanolic extract prepared from these samples was tested for antioxidant, quorum sensing and antimicrobial assays, as well as for its cytotoxicity effects. The extract showed antimicrobial activity against all tested microorganisms, including Candida albicans. Furthermore, when tested at sub-MIC concentration, it showed reduction of virulence factors and biofilm formation against Pseudomonas aeruginosa. The extract also exhibited antioxidant activity and did not show toxicity against tumor and non-tumor cells. Due to the observed bioactive properties and compounds of the honey mushroom and its well-balanced nutrients, this mushroom emerges as an interesting functional food and a source of nutraceuticals with applications in different diseases based on antioxidant and antimicrobial effects.

An insight into anti-biofilm and anti-quorum sensing activities of the selected anthocyanidins: the case study of Pseudomonas aeruginosa PAO1

Anti-biofilm activity of three anthocyanidins (pelargonidin, cyanidin and delphinidin) was evaluated for the first time at in vitro conditions. All the compounds reduced the formation of Pseudomonas aeruginosa PAO1 biofilm at low sub-MIC (0.125 MIC) with delphinidin (c 56.25 μg/mL) being the most active (43%). In comparison, ampicillin (c 93.75 μg/mL) and streptomycin (c 21.25 μg/mL) (used as positive controls) were considerably less effective at the same sub-MIC (8 and 12%, respectively). Furthermore, at 0.5 MIC (c 225 μg/mL) this anthocyanidin molecule partly reduced the bacterial protrusions. However, no any of the aforementioned compounds inhibited the production of pyocyanin by the bacterial strain P. aeruginosa PAO1. Taken all together, the delphinidin scaffold could be taken into consideration for the design of the novel and more effective anti-biofilm agents inspired by the anthocyanidins.

Heracleum orphanidis: chemical characterisation, and comparative evaluation of antioxidant and antimicrobial activities with specific interest in the influence on Pseudomonas aeruginosa PAO1

Pseudomonas aeruginosa treated with Heracleumorphanidis showed lower twitching and flagella motility.

Ethnopharmacological uses of Sempervivum tectorum L. in southern Serbia: Scientific confirmation for the use against otitis linked bacteria

ETHNOPHARMACOLOGICAL RELEVANCE

Sempervivum tectorum L. (Crassulaceae), known as houseleek, is used in traditional medicine in the treatment of ear inflammation. It can be spread as a pack on wounds, sores, burns, and abscesses and also on painful areas attacked by gout as a refrigerant and astringent. Drinking tea prepared from leaves of S. tectorum is recommended for ulcer treatment. The present study was designed to investigate ethopharmacological use of S. tectorum in the southern Serbia and to further scientifically justify and confirm effectiveness of the leaf juice used in ethnomedicine for ear inflammation, against otitis linked bacteria.

MATERIAL AND METHODS

Ethnopharmacological survey on the use of S. tectorum in southern Serbia was performed using semi structured questionnaires via a face-to-face interview. Chemical composition of the leaf juice regarding phenolic compounds and organic acids was analyzed. Antimicrobial activity was tested on bacteria isolated from ear swabs of the patients suffering from the ear pain (otitis). Anti-quorum-sensing activities of the juice were further investigated on Pseudomonas aeruginosa.

RESULTS

Ethnopharmacological survey revealed the use of S. tectorum in southern Serbia for the treatment of ear pain, warts, cancer, stomachache, ulcer and high blood sugar level with the highest fidelity level (FL) for the ear pain. The phenolic composition of the S. tectorum leaf juice consisted of flavonol glycosides, with kaempferol-3-O-rhamnosyl-glucoside-7-O-rhamnoside as the majority compound. Organic acids composition revealed malic acid as the most dominant one. Antimicrobial and anti-quorum-sensing activities of the juice showed to be promising.

CONCLUSION

Ethnopharmacological use of S. tectorum juice for treating ear pain is justified, since the juice possessed antimicrobial activity towards clinical isolates of bacteria linked to otitis.

Nutritional value, chemical composition, antioxidant activity and enrichment of cream cheese with chestnut mushroom Agrocybe aegerita (Brig.) Sing

A very well-known and appreciated mushroom, Agrocybe aegerita (Brig.) Sing, was the subject of chemical profiling, antioxidant assays and sensory evaluation test in cream cheese. Methanolic extract obtained from a wild sample of A. aegerita fruiting body was fully chemically identified. Sample was found to be rich in carbohydrates (84.51 g/100 g dw), ash and proteins (6.69 g/100 g dw and 6.68 g/100 g dw, respectively). Trehalose was the main free sugar while malic acid was the most abundant organic acid. Four isoforms of tocopherols were identified; γ- tocopherol was the dominant isoform with 86.08 μg/100 g dw, followed by β- tocopherol, δ-tocopherol and α-tocopherol (8.80 μg/100 g dw, 3.40 μg/100 g dw and 2.10 μg/100 g dw, respectively). Polyunsaturated fatty acids were predominant, with linoleic acid as the most prominent one (78.40 %). Methanolic extract of chestnut mushroom exhibited high antioxidant activity. Sensory evaluation test included grading by panelists and comparing the overall acceptability of cream cheese alone and enriched cream cheese with dry powder of A. aegerita. General conclusion of the participants was that the newly developed product was more likeable in comparison to cream cheese alone. Due to the health-beneficial effects of antioxidants and wealth of chemically identified nutrients, A. aegerita is a promising starting material for incorporation on larger scale products.