Ethanolic extracts from three commercial edibe mushrooms: determination of ergosterol contente and evaluation of bioactives properties

Mushrooms are rich in several bioactive metabolites among them are phenolic compounds, terpenoids, polysaccharides, lectins, and steroids including mycosterols, namely ergosterol [1]. Ethanolic extracts prepared by maceration of several mushroom species have been recently described as having antiinflammatory properties [2]. In the present work, ethanolic extracts of Agaricus bisporus L., Lentinus edodes (Berk.) Pegler and Pleurotus ostreatus (Jacq. ex Fr.) P.Kumm., purchased from a local supermarket in the Northeast of Portugal, were obtained by Soxhlet and chemically characterized in terms of ergosterol content by HPLC-UV. The antioxidant properties of these extracts were evaluated through DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (RSA), reducing power (RP), p. carotene bleaching inhibition (CBI) and lipid peroxidation inhibition in TBARS (thiobarbituric acid reactive substances) assay (LPI); the antioxidant activity of ergosterol was also evaluated by the DPPH assay. The anti-inflammatory activity of the same extracts and ergosterol was evaluated in LPS (lipopolysaccharide) stimulated RAW 264.7 macrophages, through the inhibition of NO production. A. bisporus revealed the highest content in ergosterol (44.8 ± 0.4 mg/ g extract) followed by P. ostreatus (34 ± 3 mg/ g extract) and finally L. edodes (8.9 ± 0.1 mg/ g extract). A. bisporus showed the highest RSA, RP and CBI (EC50 values= 7.0 ± 0.8, 2.3 ± 0.1 and 1.4 ± 0.1 mg/mL, respectively), while L. edodes presented the highest LPI (2.5 ± 0.1 mg/mL ); ergosterol revealed higher RSA (0.46±0. 0 I mg/mL) than the extracts. Concerning the anti-inflammatory potential, the most efficient species was L. edodes (lC50 value = 164 ± 16 J.lg/mL), followed by A. bisporus (185 ± 16 J.lg/mL) and finally P. ostreatus (290 ± 10 J.lg/mL). However, ergosterol presented lower activity (338 ± 23 J.lg/mL) due to its low solubility in the culture medium. The higher antioxidant properties displayed by A. bisporus can be related with its higher ergosterol content, while in the anti-inflammatory activity this relation cannot be established also due to the low solubility of ergosterol in the cells culture medium, decreasing the ergosterol availability. More studies are being conducted regarding the ergosterol solubility. Several compounds have been implicated in the bioactivity of mushrooms and in this study we have found that ergosterol can give an important contribution.

Candidacidal potential of licorice phenolic extract: emphasis on its mode of action

Medicinal plants bave gained a special attention in the last years, due to its renowned health benefits, such as antimicrobial effects [I]. In fact, several natural matrices bave been increasingly studied, namely for its antifungal activity against opportunistic fungi [2,3]. Candida species, although commensa! microorganisms, have caused severe organic dysfunctions to the host, once current antifungal agents have lost their recognized efficiency [2]. So, numerous studies have been carried out focusing the mechanisms of acquired drug-resistance by Candida species [extracts combination), the discovery of the involved mechanisms of actions, morphological changes and related kinetic parameters are of major importance. Glycyrrhiza glabra L. (licorice) hydromethanolic extract have evidenced promissory candidacidal effects, and therefore, the involved mechanisms of action need to be clarified. Thus, in the present study these modes of action were assessed, by using flow cytometry.Overall, the licorice extract induced significant and irreversible primary damages on Candida cells, being membrane disruption and consequent unviability one of the main targets. In fact, after membrane destabilization, cells lost their proper homeostasis, their metabolic functions were blocked and, consequently cells lost functionality. The relevance and interest of the achieved results open new insights towards the upcorning use of the present phenolic matrix, being important to evaluate its in viva efficacy. Therefore, further studies are necessary to deepen knowledge on this field, aiming not only to establish therapeutic and prophylactic doses, but also to improve the clinical intervention in Candida infections.

Ceratonia siliqua L. hydroethanolic extract obtained by ultrasonication: antioxidant activity, phenolic compounds profile and effects in yogurts functionalized with their free and microencapsulated forms

Bioactive extracts were obtained from powdered carob pulp through an ultrasound extraction process and then evaluated in terms of antioxidant activity. Ten minutes of ultrasonication at 375 Hz were the optimal conditions leading to an extract with the highest antioxidant effects. After its chemical characterization, which revealed the preponderance of gallotannins, the extract (free and microencapsulated) was incorporated in yogurts. The microspheres were prepared using an extract/sodium alginate ratio of 100/400 (mg mg(-1)) selected after testing different ratios. The yogurts with the free extract exhibited higher antioxidant activity than the samples added with the encapsulated extracts, showing the preserving role of alginate as a coating material. None of the forms significantly altered the yogurt's nutritional value. This study confirmed the efficiency of microencapsulation to stabilize functional ingredients in food matrices maintaining almost the structural integrity of polyphenols extracted from carob pulp and furthermore improving the antioxidant potency of the final product.