Unexplored endemic fruit species from Brazil: Antibiofilm properties, insights into mode of action, and systemic toxicity of four Eugenia spp

How does in vitro gastrointestinal digestion affect the biological activities and phenolic profile of açaí (Euterpe oleracea) and inajá (Maximiliana maripa) by-products?

This study investigates the bioactive potential and acute toxicity of açaí (Euterpe oleracea) and inajá (Maximiliana maripa) pomace extracts. The bioaccessible fraction (intestinal fraction, IF) of açaí pomace contained protocatechuic, ferulic, and vanillic acids, while inajá pomace had caffeic acid, glabridin, and an eriodictyol derivative. Both extracts showed similar total phenolic content and peroxyl radical scavenging capacity, with hypochlorous acid scavenging activity. Açaí pomace inhibited nuclear factor-κB (NF-κB) activation (85 % to 50 %) compared to inajá (33 % to 98 %), and both extracts reduced tumor necrosis factor-α (TNF-α) levels by over 81 % at 100 μg/mL, indicating anti-inflammatory properties. Acute toxicity tests in Galleria mellonella larvae showed no harmful effects at concentrations effective for antioxidant and anti-inflammatory activity. These findings suggest that açaí and inajá pomaces are promising natural sources of phenolic compounds for use in pharmaceuticals, cosmetics, and food industries.

Fruits native to South America: a narrative review of their biological properties and chemical profiles

Fruits native to South America have been recognized for their relevant levels of phytochemicals with bioactivities that offer human health benefits beyond nutrition; however, many of them remain unexplored. The objective of this study was to compile the recent literature regarding the phytochemical profiles and biological properties of fruits native to South America. Over 600 fruits were analyzed, and those with the most substantial scientific literature regarding their phytochemical profiles and antioxidant, anti-inflammatory, and antimicrobial activities were selected. Based on the reviewed literature, 40 selected fruits were analyzed, and antioxidant activity was reported for 38 fruits, antimicrobial activity for 31, and anti-inflammatory activity for 30. This data allowed for a comparative analysis of the bioactive potential of these fruits. However, factors like extraction methods, harvest time and location, and cultivar variations were found to have significant impacts on fruit bioactivity. Common limitations in properly investigating the phytochemical composition of fruits grown in the wild include lack of access to sufficient materials, lack of reproducibility of results owing to variations in chemical composition, and inability to use accurate techniques, such as mass spectrometry and nuclear magnetic resonance. Clinical trials should be encouraged to confirm the antioxidant and anti-inflammatory activities of fruits observed in vitro. Furthermore, extract refinement prior to antimicrobial analysis remains challenging to obtain reliable results. This review provides helpful information to guide further studies on these fruits and strategic public policies concerning the development of sustainable supply chains to preserve the biodiversity of South America.

Exploring quinazoline-derived copper(I) complex coated intravaginal ring against vulvovaginal candidiasis causing Candida species

Vulvovaginal candidiasis (VVC) is especially prevalent among intrauterine device (IUD) and intravaginal ring (IVR) users. Candida albicans is the leading causative agent of VVC followed by Candida glabrata. Ascribed to the increased drug resistance by Candida spp. to the currently available drugs, this study has focused on the novel quinazoline-derived copper(I) complexes as anti-candida agents. As a novel approach, a vaginal ring was coated with the best quinazoline-derived copper(I) complex, and biofilm disruption ability was evaluated. The coated vaginal ring eradicated 70% of preformed biofilms and also inhibited the hyphal transition of Candida albicans in a simulated vaginal fluid (SVF). The overall study validates the anti-biofilm and anti-virulent properties of the metal complex-coated vaginal ring using various microscopic studies.

Exploring the Epicarp Potential from Acrocomia aculeata Fruits: Chemical Analysis, Antioxidant and Antimicrobial Activities

The interest in new sources of bioactive compounds has been driven by the search for natural antioxidants capable of attenuating the toxicity of reactive oxygen species, as well as the emergence of pathogens resistant to antimicrobials. In this sense, we explored the potential of the macaúba epicarp. Compounds such as piceatannol, 3,4,5,3',5'-penta-hydroxy-trans-stilbene (PHS), and in lower amounts, resveratrol were identified in extracts through techniques such as medium-pressure liquid chromatography, HPLC-MS, and imaging mass spectrometry (IMS), which confirmed the exclusive localization of PHS and piceatannol in the outer epicarp. Extraction with aqueous acetone (Me2CO:H2O) and its EtOAC fraction showed the highest yields of stilbenes and, moreover, it efficiently increased the tolerance of Saccharomyces cerevisiae to oxidative stress. Additionally, the Me2CO:H2O extract presented antibacterial and anti-cryptococcal activity, with piceatannol and resveratrol increasing survival rates of Galleria mellonella subjected to fungal infection. In silico ADMET (absorption, distribution, metabolism, excretion and toxicity) analysis indicates low toxicity for piceatannol, PHS, and resveratrol, in addition to pharmacokinetic parameters that allow their use. These findings indicate the use of macaúba epicarp as a source of bioactive compounds valuable for the food, cosmetic, and pharmaceutical industries.

A Comparative Study of the Biological Properties of Eugenia uniflora L. Fruits and Leaves Related to the Prevention of Cardiovascular Diseases

Cardiovascular diseases (CVDs) remain the leading cause of death globally, emphasizing the need for effective preventive strategies. Plant-based foods, rich in phytochemicals, offer a promising potential in CVD prevention. This study investigated the antioxidant, anti-inflammatory, and antihypertensive properties of two Eugenia uniflora L. varieties (orange and purple pitanga) and their leaves. Their antioxidant activity was assessed using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging activity assays, while their antihypertensive activity was evaluated through angiotensin-converting enzyme (ACE) inhibition. Their anti-inflammatory potential was determined via protein denaturation inhibition. Both fruit varieties exhibited similar bioactivities, with the purple variety showing a slightly higher activity, except in the DPPH and ABTS assays. The leaves consistently demonstrated the lowest activities across all assays. Free polyphenols, dominated by gallic acid, were quantified using µ-QuEChERS followed by ultrahigh-performance liquid chromatography (UHPLC-PDA). The orange variety contained the highest concentration of gallic acid (13.1 mg/100 g DW). These findings highlight the potential of Eugenia uniflora L. extracts as natural antioxidant, anti-inflammatory, and antihypertensive agents, suggesting their value in food, pharmaceutical, and cosmetic applications for promoting human health and preventing CVDs.

Biocultural heritage of the Caatinga: a systematic review of Myrtaceae and its multiple uses

The Caatinga, an exclusively Brazilian biome, stands as a reservoir of remarkable biodiversity. Its significance transcends ecological dimensions, given the direct reliance of the local population on its resources for sustenance and healthcare. While Myrtaceae, a pivotal botanical family within the Brazilian flora, has been extensively explored for its medicinal and nutritional attributes, scant attention has been directed towards its contextual relevance within the Caatinga's local communities. Consequently, this inaugural systematic review addresses the ethnobotanical roles of Myrtaceae within the Caatinga, meticulously anchored in the PRISMA 2020 guidelines. We searched Scopus, MEDLINE/Pubmed, Scielo, and LILIACS. No date-range filter was applied. An initial pool of 203 articles was carefully scrutinized, ultimately yielding 31 pertinent ethnobotanical studies elucidating the utility of Myrtaceae amongst the Caatinga's indigenous populations. Collectively, they revealed seven distinct utilization categories spanning ~54 species and 11 genera. Psidium and Eugenia were the genera with the most applications. The most cited categories of use were food (27 species) and medicinal (22 species). The importance of accurate species identification was highlighted, as many studies did not provide enough information for reliable identification. Additionally, the potential contribution of Myrtaceae fruits to food security and human health was explored. The diversity of uses demonstrates how this family is a valuable resource for local communities, providing sources of food, medicine, energy, and construction materials. This systematic review also highlights the need for more ethnobotanical studies to understand fully the relevance of Myrtaceae species in the Caatinga, promoting biodiversity conservation, as well as support for local populations.

Antimicrobial and antibiofilm activities of Inga cylindrica trypsin inhibitor

Inga cylindrica, a tropical fruit tree of the Fabaceae family (subfamily Mimosoideae), is native to South America. The seeds from this family are an essential source of trypsin inhibitors, which display promising bioactivity for increasing host defense against pathogens. The aim of the present study was to characterize the antimicrobial and antibiofilm activities of the trypsin inhibitor extracted from I. cylindrica seeds, ICTI. ICTI demonstrated antifungal activity with a minimum inhibitory concentration (MIC) of 32.11 μmol.L-1, and a minimum fungicidal concentration (MFC) of 32.1 μmol.L-1, against Cryptococcus gattii, Candida albicans, Candida glabrata and Candida guilliermondii. Combining ICTI with Amphotericin B had a significant synergistic effect, reducing the concentration of the antibiotic by 75% for C. albicans and 94% for C. gatti. The significant increase (16 x) in activity observed with ergosterol (1.01 mol.L-1) for C. albicans and C. gatti, and the lack of activity against bacterial strains, suggests that ICTI interferes with the integrity of the fungal cell membrane. Treatment with ICTI at 10 x MIC resulted in a 51% reduction in biofilm formation and a 56% decrease in mature biofilm colonies for C. albicans. Finally, ICTI displayed no toxicity in the in vivo Galleria mellonella model. Given its antifungal and antibiofilm properties, ICTI could be a promising candidate for the development of new antimicrobial drug prototypes.

Bioactive potential of Eugenia luschnathiana essential oil and extract: antifungal activity against Candida species isolated from oncological patients

Immunosuppressed individuals, including those undergoing cancer treatment, are more vulnerable to fungal infections, such as oral candidiasis, impacting their quality of life. Given the limitations of current therapies, the discovery of new antifungal agents, including those of natural origin, is crucial for the proper managing of these infections. We investigated the phytochemical profile and antifungal activity of both the essential oil and crude ethanolic extract (CEE) obtained from Eugenia luschnathiana against reference strains and clinical isolates of Candida from oncology patients. Toxicological characterization was also conducted. Gas chromatography coupled to mass spectrometry (GC-MS) and 1H Nuclear Magnetic Resonance (NMR) were used for phytochemical analysis. Antifungal evaluation was conducted to determine the Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC); evaluation of potential mechanisms of action; activity on a fungal biofilm; evaluation of the cytotoxic effect on human keratinocytes of the HaCat lineage by the MTT method; determination of lethality for Artemia salina larvae. GC-MS identified a predominance of sesquiterpenes in the essential oil, notably (E)-Caryophyllene. The 1H NMR spectrum identified aliphatic, osidic, and aromatic compounds in the crude ethanolic extract. The essential oil showed no antifungal activity. However, the CEE exhibited fungicidal activity, with MIC and MFC ranging from 1.95 µg/mL to 3.90 µg/mL. The antifungal effect was affected by sorbitol, indicating a possible mechanism targeting fungal cell wall structures. At low concentration (19.5 µg/mL), the CEE inhibited 62,78% of C. albicans biofilm. The CEE demonstrated a promising toxicity profile, with an LC50 of 142.4 µg/mL against Artemia salina. In conclusion, the CEE from Eugenia luschnathiana exhibited potent antifungal activity, likely through cell wall disruption, biofilm inhibition, and a favorable toxicity profile for further exploration.

Exploring the toxicity profile of coriander (C. sativum L.) essential oil: implications for translational toxicological research

The plant species C. sativum L. is a staple in cuisine and holds significant ethnopharmacological value. Its essential oil (EO) is of particular interest, yet its toxicity profile remains a subject of inquiry. This study aimed to elucidate the chemical constituents of C. sativum L. EO and evaluate its toxicity through various parameters, including cytotoxicity assays on HaCaT keratinocytes, in vivo toxicity tests on Galleria mellonella larvae, in vivo genotoxicity assessments on mice and cytotoxicity assays on human erythrocytes. Notably, major constituents such as 2-decen-1-ol, dec-(2E)-enal, and 1,6-octadien-3-ol were found to remain predominant. The IC50 value for the essential oil on the keratinocyte cell line was determined to be 60.13 ± 2.02 µg/mL. However, in vivo toxicity tests with G. mellonella larvae demonstrated safety at doses below 4.5 g/kg. Additionally, genotoxicity assessment revealed that a single dose of 20 mg/mL (5 mg/kg) did not induce a significant increase in micronuclei formation. EO concentrations above 250 µg/mL led to significant changes in human erythrocytes cell viability (p < 0.0001), resulting in over 60% hemolysis. These findings collectively suggest that the essential oil of C. sativum L. exhibits a suitable toxicity profile for conducting preclinical studies in vertebrate animal models.

Tissue Culture Innovations for Propagation and Conservation of Myrteae-A Globally Important Myrtaceae Tribe

Myrteae is the most species-rich tribe in the Myrtaceae family, represented by a range of socioeconomically and ecologically significant species. Many of these species, including commercially relevant ones, have become increasingly threatened in the wild, and now require conservation actions. Tissue culture presents an appropriate in vitro tool to facilitate medium-term and long-term wild germplasm conservation, as well as for commercial propagation to maintain desirable traits of commercial cultivars. So far, tissue culture has not been extensively achieved for Myrteae. Here, tissue culture for Eugenia, one of the most species-rich genera in Myrteae, is reviewed, giving directions for other related Myrteae. This review also focuses on ex situ conservation of Australian Myrteae, including using seed banking and field banking. Despite some progress, challenges to conserve these species remain, mostly due to the increasing threats in the wild and limited research. Research into in vitro methods (tissue culture and cryopreservation) is paramount given that at least some of the species are 'non-orthodox'. There is an urgent need to develop long-term in vitro conservation for capturing the remaining germplasm of threatened Myrteae.

Barbosa E, Rocha HAO, Chaves GM. Mechanism of action and synergistic effect of Eugenia uniflora extract in Candida spp

The limited arsenal of antifungal drugs have prompted the search for novel molecules with biological activity. This study aimed to characterize the antifungal mechanism of action of Eugenia uniflora extract and its synergistic activity with commercially available antifungal drugs on the following Candida species: C. albicans, C. tropicalis, C. glabrata, C. parapsilosis and C. dubliniensis. In silico analysis was performed to predict antifungal activity of the major compounds present in the extract. Minimal inhibitory concentrations (MICs) were determined in the presence of exogenous ergosterol and sorbitol. Yeast cells were grown in the presence of stressors. The loss of membrane integrity was assessed using propidium iodide staining (fluorescence emission). Synergism between the extract and antifungal compounds (in addition to time kill-curves) was determined. Molecular docking revealed possible interactions between myricitrin and acid gallic and enzymes involved in ergosterol and cell wall biosynthesis. Candida cells grown in the presence of the extract with addition of exogenous ergosterol and sorbitol showed 2 to 8-fold increased MICs. Strains treated with the extract revealed greater loss of membrane integrity when compared to their Fluconazole counterparts, but this effect was less pronounced than the membrane damage caused by Amphotericin B. The extract also made the strains more susceptible to Congo red and Calcofluor white. A synergistic action of the extract with Fluconazole and Micafungin was observed. The E. uniflora extract may be a viable option for the treatment of Candida infections.

Influence of Major Polyphenols on the Anti-Candida Activity of Eugenia uniflora Leaves: Isolation, LC-ESI-HRMS/MS Characterization and In Vitro Evaluation

The content of chemical constituents in Eugenia uniflora leaf extracts correlates positively with biological activities. The experimental objective was to carry out the phytochemical screening and purification of the major polyphenols from the leaves of E. uniflora. In addition, the anti-Candida activity of the hydroalcoholic extract, fraction, subfractions and polyphenols purified were evaluated. After partitioning of the extract with ethyl acetate, the fractions were chromatographed on Sephadex® LH-20 gel followed by RP-flash chromatography and monitored by TLC and RP-HPLC. The samples were characterized by mass spectrometry (LC-ESI-QTOF-MS2) and subjected to the microdilution method in 96-well plates against strains of C. albicans, C. auris, and C. glabrata. Myricitrin (93.89%; w/w; m/z 463.0876), gallic acid (99.9%; w/w; m/z 169.0142), and ellagic acid (94.2%; w/w; m/z 300.9988) were recovered. The polyphenolic fraction (62.67% (w/w) myricitrin) and the ellagic fraction (67.86% (w/w) ellagic acid) showed the best antifungal performance (MIC between 62.50 and 500 μg/mL), suggesting an association between the majority constituents and the antifungal response of E. uniflora derivatives. However, there is a clear dependence on the presence of the complex chemical mixture. In conclusion, chromatographic strategies were effectively employed to recover the major polyphenols from the leaves of the species.

Emerging berries from the Brazilian Amazon and Atlantic Forest biomes: new sources of bioactive compounds with potential health benefits

Brazil has a broad geographic biodiversity spread across its six different biomes. However, it has been suffering from the abusive exploitation of its resources, which poses a threat to the local fauna and flora. The Amazon and Atlantic Forest, for example, are birthplaces to rare and edible native species, such as bacaba (Oenocarpus bacaba, Arecaceae) and camu-camu (Myrciaria dubia, Myrtaceae), and cereja-do-Rio Grande (Eugenia involucrata, Myrtaceae) and grumixama (Eugenia brasiliensis, Myrtaceae), respectively. These plants produce fruits which are sources of macro and micronutrients, including sugars, dietary fibers, vitamins, minerals, and/or lipids. Nutritionally, their consumption have the ability to reach partially or totally the daily recommendations for adults of some nutrients. More recently, these fruits have also been exposed as interesting sources of minor bioactive compounds, such as carotenoids, terpenes, and/or polyphenols, the latter which include anthocyanins, phenolic acids, and tannins. Particularly, bacaba stands out for being a rich source of polyunsaturated fatty acids (around 22%, dry weight) and dietary fibers (6.5-21%, dry weight); camu-camu has very high contents of vitamin C (up to 5000 mg per 100 g of pulp, dry basis); and cereja-do-Rio-Grande and grumixama are abundant sources of anthocyanins. Although they are still underexplored, several in vitro and in vivo studies with different parts of the fruits, including the peel, seed, and pulp, indicate their health potential through anti-oxidative, anti-obesity, antihyperglycemic, antidyslipidemic, antimicrobial, and/or anticancer effects. All things considered, the focus of this research was to highlight the bioactive potential and health impact of native fruits from the Amazon and Atlantic Forest biomes.

Effects of bioconversion by Battus polydamas on the chemical composition of Aristolochia spp. and evaluation of antimicrobial activity and biocompatibility

Aristolochia plants are emblematic from an ethnopharmacological viewpoint and are know to possess numerous biological properties, including antiseptic. However, the medicinal potential of these species is debatable because of their representative chemical constituents, aristolochic acids (AAs) and aristolactams (ALs), which are associated, for instance, with nephropathy and cancer. These contrasting issues have stimulated the development of approaches intended to detoxification of aristoloquiaceous biomasses, among which is included the bioconversion method using larvae of the specialist phytophagous insect Battus polydamas, previously shown to be viable for chemical diversification and to reduce toxicity. Thus, eleven Aristolochia spp. were bioconverted, and the antimicrobial activities of the plant methanolic extracts and its respective bioconversion products were evaluated. The best results were found for Aristolochia esperanzae, Aristolochia gibertii, and Aristolochia ringens against Bacillus cereus, with MIC ranging from 7.8 to 31.25 μg/mL. These three species were selected for chemical, antioxidant, cytotoxic, hemolytic, and mutagenic analyses. Chemical analysis revealed 65 compounds, 21 of them possible bioconversion products. The extracts showed potential to inhibit the formation and degradation of B. cereus biofilms. Extracts of A. gibertii and its bioconverted biomass showed antioxidant activity comparable to dibutylhydroxytoluene (BHT) standard. Bioconversion decreased the hemolytic activity of A. esperanzae and the cytotoxicities of A. esperanzae and A. gibertii. None of the extracts was found to be mutagenic. The bioactivities of the fecal extracts were maintained, and biocompatibility was improved. Therefore, the results obtained in this study reveal positive expectations about the natural detoxification process of the Aristolochia species.

Diacetylcurcumin: a novel strategy against Enterococcus faecalis biofilm in root canal disinfection

Aim: We evaluated Diacetylcurcumin (DAC), a derivative of curcumin, for its antibacterial and antibiofilm properties against Enterococcus faecalis. Methods: Minimum inhibitory concentration (MIC) and minimum bactericidal concentration were determined, along with antibiofilm potential and toxicity in Galleria mellonella. Additionally, in silico computational analysis was performed to understand its mechanisms of action. Results & conclusion: DAC demonstrated significant antibacterial effects, with MIC and MBC values of 15.6 and 31.25 μg/ml, respectively, and reduced biofilm formation. A synergistic effect, reducing biofilm by 77%, was observed when combined with calcium hydroxide. G. mellonella toxicity tests confirmed DAC's safety at tested concentrations, suggesting its potential for use in root canal disinfection products.

A green method for anthocyanin extraction from Clitoria ternatea flowers cultivated in southern Brazil: Characterization, in vivo toxicity, and biological activity

This study aimed to develop a green method to obtain an anthocyanin-rich edible extract of Clitoria ternatea flowers grown in southern Brazil. The extract was characterized by UHPLC-MSn and analyzed for toxicological potential in an in vivo model, total phenolic content, and biological activities. By using a 23 multivariate design to study the effects of temperature, acidified solvent, and time on the total anthocyanin content (487.25 mg/g), total phenolic content (2242.47 mgGAE/g), it was possible to determine the optimal point (45 °C, 16 min, and 22.5 mL extraction solution). Thirteen anthocyanins and nine non-anthocyanins were quantified. In vivo toxicity assay using Galleria mellonella showed a safe concentration when administered up to 2.2 g of extract per body kg. The extract showed antioxidant activity and antibacterial action against food pathogens, the method proved to have a low environmental impact, in addition to producing an extract with potential for application in food.

Antifungal activity of 3,3'-dimethoxycurcumin (DMC) against dermatophytes and Candida species

Dermatomycosis is an infection with global impacts caused especially by dermatophytes and Candida species. Current antifungal therapies involve drugs that face fungal resistance barriers. This clinical context emphasizes the need to discover new antifungal agents. Herein, the antifungal potential of 10 curcumin analogs was evaluated against four Candida and four dermatophyte species. The most active compound, 3,3'-dimethoxycurcumin, exhibited minimum inhibitory concentration values ranging from 1.9‒62.5 to 15.6‒62.5 µg ml-1 against dermatophytes and Candida species, respectively. According to the checkerboard method, the association between DMC and terbinafine demonstrated a synergistic effect against Trichophyton mentagrophytes and Epidermophyton floccosum. Ergosterol binding test indicated DMC forms a complex with ergosterol of Candida albicans, C. krusei, and C. tropicalis. However, results from the sorbitol protection assay indicated that DMC had no effect on the cell walls of Candida species. The in vivo toxicity, using Galleria mellonella larvae, indicated no toxic effect of DMC. Altogether, curcumin analog DMC was a promising antifungal agent with a promising ability to act against Candida and dermatophyte species.

Purple pitanga extract (Eugenia uniflora) attenuates oxidative stress induced by MPTP

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) has been widely used due to its specific and reproducible neurotoxic effect on the nigrostriatal system, being considered a convenient model of dopaminergic neurodegeneration to study interventions therapeutics. The purple pitanga (Eugenia uniflora) is a polyphenol-rich fruit with antioxidant and antidepressant properties, among others. Therefore, this study investigated the effect of purple pitanga extract (PPE) on acute early oxidative stress induced by intranasal 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration in rats. Male Wistar rats were pre-treated orally with PPE (1000 mg/kg) or vehicle. After 24 h, MPTP (0.1 mg/10µL/nostril) or vehicle was administered bilaterally into the animal's nostrils, and 6 h later, the olfactory bulb (OB), striatum (ST), and substantia nigra (SN) were collected to evaluate the oxidative stress parameters. Our findings revealed that OB and SN were the most affected areas after 6 h of MPTP infusion; an early increase in reactive oxygen species (ROS) levels was observed, while pretreatment with a single dose of PPE prevented this increment. No differences in thiobarbituric acid reactive species (TBARS) and 3-nitrotyrosine (3-NT) formation were observed, although 4-hydroxy-2-nonenal (4-HNE) levels increased, which is the most toxic form of lipid peroxidation, in the MPTP group. The PPE pretreatment could prevent this increase by increasing the NPSH levels previously decreased by MPTP. Furthermore, PPE prevents the Na+/K + ATPase strongly inhibited by MPTP, showing the neuroprotective capacity of the PPE by inhibiting the MPTP-generated oxidation. Thus, we demonstrated for the first time the antioxidant and neuroprotective effects of PPE against the early MPTP neurotoxicity.

Improving Drug Delivery on Candida Albicans Using Geraniol Nanoemulsion

Geraniol (GE) is a monoterpene alcohol with excellent antifungal activity. However, its low solubility and high volatility impair its use. Nanoemulsions (NE) are excellent delivery systems for poorly soluble and volatile drugs, achieving controlled release of the active ingredient. The aim of this study was to improve the delivery of geraniol (GE) incorporated in NE against Candida albicans in order to evaluate the antibiofilm effect and cytotoxicity. Nanoemulsion containing 10% oil phase (cholesterol) (w/w), 10% surfactant (mixture of soy phosphatidylcholine and Brij 58; 1:2) (w/w), and 80% aqueous phase (phosphate buffer) (w/w) was synthesized. Incorporation of GE was carried out by sonication and the final compounds were characterized by hydrodynamic diameter, polydispersity index (PDI), and zeta potential (ZP), in addition to evaluation of physicochemical stability after 6 months and 1 year. The GE-NE effect was evaluated on Candida albicans biofilms and cytotoxic effect was evaluated on immortalized normal oral cell line NOK-Si. The diameter of GE-NE was 232.3 ± 2.7 nm and PDI 0.155 with exhibited homogeneity and stability in solution. GE-NE showed antibiofilm activity at a concentration of 75 μg/mL with reduction of >6.0 log10, and no cytotoxicity against NOK-Si cells at concentrations below 150 μg/mL was observed. GE-NE proved to be a promising candidate for prevention and treatment of fungal diseases.

Cocoa powder and fermented jackfruit seed flour: A comparative cell-based study on their potential antioxidant and anti-inflammatory activities after simulated gastrointestinal digestion

BACKGROUND

Jackfruit seed flour can be used as a cocoa aroma replacer with similar technological properties. The purpose of this study was to investigate the in vivo toxicity and in vitro antioxidant activity of fermented jackfruit seed flour (Fjs) and non-alkaline cocoa powder (Nac).

RESULTS

Fjs and Nac extracts (Fjs-E and Nac-E) were produced and submitted to in vitro gastrointestinal digestion producing digested fractions named Fjs-D and Nac-D, respectively. Nac-E showed over two-fold higher oxygen radical absorbance capacity (ORAC) than Fjs-E. However, after simulated gastrointestinal digestion (in vitro), there were no significant differences between Nac-D and Fjs-D (P < 0.01). Similarly, the cellular antioxidant activity (CAA) of Nac-D and Fjs-D was not significantly different (P < 0.01). The anti-inflammatory assay in transgenic RAW 264.7 murine macrophages showed that Fjs-E did not affect cell viability up to 300 μg mL^-1 (P > 0.05) and reduced by 15% the release of TNF-α (P < 0.05). Fjs-D did not affect cell viability up to 300 μg mL^-1 (P > 0.05) and showed 58% reduction of NF-κB activation (P < 0.05), with no effects on TNF-α levels. Treatment with Nac-E up to 300 μg mL^-1 did not decrease cell viability (P > 0.05) and reduced the release of TNF-α levels by 34% and 66% at 100 and 300 μg mL^-1 , respectively (P < 0.05). Nac-D did not reduce the NF-κB activation or TNF-α levels at any tested concentration.

CONCLUSION

Collectively, these findings indicate that Fjs is a safe and promising functional ingredient with biological activities even after gastrointestinal digestion. © 2023 Society of Chemical Industry.

Eugenia uniflora: a promising natural alternative against multidrug-resistant bacteria

This work aimed to evaluate the chemical composition, antioxidant and antimicrobial activities from crude extract and fractions from leaves of Eugenia uniflora Linn. The crude extract was obtained by turbo extraction and their fractions by partitioning. Chromatographic analysis were performed, and the antioxidant capacity was verified by two methods (DPPH• and ABTS•+). The Minimal Inhibitory/Bactericidal Concentration were conducted against twenty-two bacteria, selecting five strains susceptible to extract/fractions and resistant to the antibiotics tested. Ampicillin, azithromycin, ciprofloxacin, and gentamicin were associated with Ethyl Acetate Fraction (EAF) against multidrug-resistant strains in modulatory and checkerboard tests. The chromatographic data showed gallic acid, ellagic acid, and myricitrin in crude extract, with enrichment in the EAF. The electron transfer activity demonstrated in the antioxidant tests is related to the presence of flavonoids. The Gram-positive strains were more susceptible to EAF, and their action spectra were improved by association, comprising Gram-negative bacilli. Synergisms were observed to ciprofloxacin and gentamicin against Pseudomonas aeruginosa colistin-resistant. The results demonstrate that the extract and enriched fraction obtained from the leaves of E. uniflora act as a promising natural alternative against multidrug-resistant bacteria.

Dynamic gastrointestinal digestion/intestinal permeability of encapsulated and nonencapsulated Brazilian red propolis: Active compounds stability and bioactivity

The objectives were to investigate the effect of dynamic gastrointestinal digestion/Caco-2 cell transport on active compounds stability and antioxidant/anti-inflammatory activities of the ethanolic extract of Brazilian red propolis (EEBRP), whether encapsulated or not; and the in vivo acute toxicity of the EEBRP after digestion. Eight isoflavonoids, one flavanone, and one chalcone were identified by HPLC-ESI-QTOF-MS, and quantified by HPLC-PDA. Bioaccessibility was higher for the encapsulated EEBRP (21.4%-57.6%) than for the nonencapsulated (19.3%-30.2%). Conversely, the Caco-2 cell transport was higher for the nonencapsulated EEBRP. Similarly, the nonencapsulated EEBRP showed higher ability to scavenge reactive oxygen species, which was especially attributed to calycosin, and to decrease NF-κB activation, and the levels of TNF-α and CXCL2/MIP-2 after Caco-2 cell transport. Hence, there is an indication that EEBRP is a promising alternative dietary source of bioavailable isoflavonoids. Further studies on encapsulation should be encouraged to improve bioactivity, and expand its food applications.

Toxicological and pharmacological effects of Eugenia brasiliensis Lam. (Myrtaceae) leaves in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Eugenia brasiliensis Lam., popularly known as "grumixama" or "Brazilian cherry", is widely used in folk medicine with astringent, diuretic, energizing, anti-rheumatic, and anti-inflammatory properties.

AIM OF THE STUDY

Despite its traditional use, detailed toxicological studies of Eugenia brasiliensis are few. Thus, in the current study, we evaluate the toxicological effects of hydroalcoholic extract of Eugenia brasiliensis (HEEb) and its antinociceptive and anti-inflammatory activity.

MATERIALS AND METHODS

We used male, and female Swiss mice. Acute toxicity study was performed following the Organization for Economic Cooperation and Development (OECD) guideline 425, and subacute toxicity was assessed following OECD guideline 407. We observed behavioral responses, in addition to hematological, biochemical, and histological evaluations. The antinociceptive and anti-inflammatory activity of HEEb were assessed using the Carrageenan-induced mechanical allodynia and paw edema model. Mechanical allodynia, levels of inflammatory cytokines, and oxidative damage were evaluated.

RESULTS

The treatment with HEEb was not able to generate important toxicological alterations. Moreover, doses of 100 and 300 mg/kg of HEEb were able to reduce mechanical allodynia, paw edema, and inflammatory cytokines (TNF-α, IL-1β, and IL-6), decrease malondialdehyde and increase superoxide dismutase enzyme activity in the paw.

CONCLUSIONS

This study demonstrated that HEEb does not present important toxic effects. Additionally, an important antinociceptive, anti-inflammatory, and antioxidant potential were observed.

Brazilian berry waste as a source of bioactive compounds: grumixama (Eugenia brasiliensis Lam.) as a case study

Grumixama, Eugenia brasiliensis Lam., is a Brazilian berry little explored commercially and scientifically. However, local small producers market this fruit in the form of frozen pulp, which generates bioresidues, composed of seeds and peels. With the view to propose strategies for valuing grumixama, this study aimed to determine the chemical composition and assess the bioactivities of the hydroethanolic extracts of the whole residue (GR), seed (GS) and peel (GP) fractions of E. brasiliensis. From the results, GP had the highest concentration of organic acids (oxalic, malic, ascorbic and citric acids), total tocopherols, condensed tannins, anthocyanins, and other flavonoids. On the other hand, GS showed the highest content of monounsaturated fatty acids and hydrolysable tannins, whereas GR displayed a mixture of compounds detected in each of its parts. Regarding the bioactivities, low extract concentrations were required in two in vitro antioxidant assays, namely TBARS (EC₅₀ = 0.90-1.34 μg mL^-1) and OxHLIA (IC₅₀ = 21-65 μg mL^-1). Furthermore, GP had the highest inhibition activity of cellular oxidation in the CAA assay (80 ± 0.6%), while GS showed the highest anti-inflammatory activity via nitric oxide production inhibition (EC₅₀ = 98.0 ± 0.5 μg mL^-1). All samples induced cell growth inhibition of the tested tumor cells (GI₅₀ = 14.7-186 μg mL^-1) besides antibacterial and antifungal effects at low concentrations, but all samples were harmful to normal cells at moderate concentrations (GI₅₀ = 145-268 μg mL^-1). Therefore, E. brasiliensis residue could be a good source of bioactive compounds to be used in several areas. However, additional studies are needed to confirm its safety as well as to unravel the mechanisms behind its biological activities.

Effects of Euterpe oleracea Mart. extract on Candida spp. biofilms

PROBLEM OF RESEARCH

Candida spp. biofilms are complex microbial communities that have been associated with increasing resistance to clinically available antifungal drugs. Hence, novel pharmacological approaches with ability to inhibit biofilm formation have been investigated.

AIM OF STUDY

The aim was to analyze in vitro antifungal activity of Euterpe oleracea Mart. (açaí berry) extract on biofilm strains of Candida albicans, C. parapsilosis, and C. tropicalis that were formed on abiotic surfaces.

REMARKABLE METHODOLOGY

Biofilms of C. albicans, C. parapsilosis, and C. tropicalis were grown in vitro. They were then treated with E. oleracea Mart. extract at different concentrations (7.8, 15.6, 31.2, 62.5, 125, 250, 500, and 1000 μg/mL) for evaluation of both biofilm removal and anti-biofilm activity.

REMARKABLE RESULTS

All Candida species analyzed formed biofilms on abiotic surfaces. Yet, increased biofilm formation was displayed for C. tropicalis in comparison with the other two species. E. oleracea Mart. extract was shown to inhibit biofilm formation at all concentrations used when compared to no treatment (p < 0.05).

SIGNIFICANCE OF THE STUDY

In the current study, the extract of E. oleracea Mart. demonstrated antifungal activity against Candida albicans, C. parapsilosis, and C. tropicalis biofilms, regardless of the dose utilized. These results are important to evaluate a natural product as antifungal for Candida species.

Natural Medicine a Promising Candidate in Combating Microbial Biofilm

Studies on biofilm-related infections are gaining prominence owing to their involvement in most clinical infections and seriously threatening global public health. A biofilm is a natural form of bacterial growth ubiquitous in ecological niches, considered to be a generic survival mechanism adopted by both pathogenic and non-pathogenic microorganisms and entailing heterogeneous cell development within the matrix. In the ecological niche, quorum sensing is a communication channel that is crucial to developing biofilms. Biofilm formation leads to increased resistance to unfavourable ecological effects, comprising resistance to antibiotics and antimicrobial agents. Biofilms are frequently combated with modern conventional medicines such as antibiotics, but at present, they are considered inadequate for the treatment of multi-drug resistance; therefore, it is vital to discover some new antimicrobial agents that can prevent the production and growth of biofilm, in addition to minimizing the side effects of such therapies. In the search for some alternative and safe therapies, natural plant-derived phytomedicines are gaining popularity among the research community. Phytomedicines are natural agents derived from natural plants. These plant-derived agents may include flavonoids, terpenoids, lectins, alkaloids, polypeptides, polyacetylenes, phenolics, and essential oils. Since they are natural agents, they cause minimal side effects, so could be administered with dose flexibility. It is vital to discover some new antimicrobial agents that can control the production and growth of biofilms. This review summarizes and analyzes the efficacy characteristics and corresponding mechanisms of natural-product-based antibiofilm agents, i.e., phytochemicals, biosurfactants, antimicrobial peptides, and their sources, along with their mechanism, quorum sensing signalling pathways, disrupting extracellular matrix adhesion. The review also provides some other strategies to inhibit biofilm-related illness. The prepared list of newly discovered natural antibiofilm agents could help in devising novel strategies for biofilm-associated infections.

The Cytotoxic and Inhibitory Effects of Plant Derivatives on Candida albicans Biofilms: A Scoping Review

Candida albicans infections are related to biofilm formation. The increase in antifungal resistance and their adverse effects have led to the search for therapeutic options as plant derivatives. This scoping review aims to identify the current status of in vitro research on the cytotoxicity and inhibitory effects of plant derivatives on C. albicans biofilms. In this study, PRISMA items were followed. After recognition of the inclusion criteria, full texts were read and disagreements were resolved with a third party. A risk of bias assessment was performed, and information was summarized using Microsoft Office Excel. Thirty-nine papers fulfilling the selection criteria were included. The risk of bias analysis identified most of the studies as low risk. Studies evaluated plant derivatives such as extracts, essential oils, terpenes, alkaloids, flavonoids and polyphenols. Some studies evaluated the inhibition of C. albicans biofilm formation, inhibition on preformed biofilms or both. The derivatives at concentrations greater than or equal to those that have an inhibitory effect on C. albicans biofilms, without showing cytotoxicity, include magnoflorin, ellagic acid, myricetin and eucarobustol from Eucalyptus robusta and, as the works in which these derivatives were studied are of good quality, it is desirable to carry out study in other experimental phases, with methodologies that generate comparable information.

Prevention of hospital pathogen biofilm formation by antimicrobial peptide KWI18

This study investigated the antimicrobial and antibiofilm activity of KWI18, a new synthetic peptide. KWI18 was tested against planktonic cells and Pseudomonas aeruginosa and Candida parapsilosis biofilms. Time-kill and synergism assays were performed. Sorbitol, ergosterol, lipid peroxidation, and protein oxidation assays were used to gain insight into the mechanism of action of the peptide. Toxicity was evaluated against erythrocytes and Galleria mellonella. KWI18 showed antimicrobial activity, with minimum inhibitory concentration (MIC) values ranging from 0.5 to 10 μM. KWI18 at 10 × MIC reduced P. aeruginosa and C. parapsilosis biofilm formation and cell viability. Time-kill assays revealed that KWI18 inhibited the growth of P. aeruginosa in 4 h and that of C. parapsilosis in 6 h. The mechanism of action was related to ergosterol as well as induction of oxidative damage in cells and biofilms. Furthermore, KWI18 demonstrated low toxicity to erythrocytes and G. mellonella. KWI18 proved to be an effective antibiofilm agent, opening opportunities for the development of new antimicrobials.

Evaluation of the antiproliferative potential of Eugenia pyriformis leaves in cervical cancer cells

Eugenia pyriformis , typically known as uvaia, ubaia, uvaieira, uvalha or uvalha-do-campo, is a plant representative of the Myrtaceae family. E. pyriformis decreased HeLa cells proliferation, can induce cell death and reduce cell migration that may be related to metastasis and induction of cell death by apoptosis in vitro assays. Its leaves are used in folk medicine for hypertension control, decreased cholesterol and uric acid, slimming, astringent, and digestive. In this work, the evaluation of the in vitro anticancer potential Cervical Cancer (HeLa cells) and phytochemical analysis in E. pyriformes was performed. It was possible to quantify phenolic compounds and total flavonoids and identify Chlorogenic acid, Quercetrin, and Myricitrin in this species. The crude extract and ethyl acetate fraction inhibited cell viability by 50% in the dose of 44.42 μg/mL and 40.39 μg/mL, respectively. The induced effector caspase 3/7 activation, which results in apoptosis and the ethyl acetate fraction , decreases cell migration of cancer cell line; it is responsible for the cleavage of several cellular proteins that will result in the classic phenotype of the apoptotic cell.

The phytoactive constituents of Eugenia selloi B.D. Jacks (pitangatuba): Toxicity and elucidation of their anti-inflammatory mechanism(s) of action

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Purified subfraction from Eugenia selloi fruit, showed anti-inflammatory activity.

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It were identified isomers of quercetrin, vanillic acid, and coumaric acid.

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S8 reduced NF-κB, IL-1β, IL-6, IL-10, MDC and MCP-1 levels in macrophages.

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S8 reduced neutrophil migration and ICAM-1 expression in mice.

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S8 showed scavenging capacity against ROO^•, HOCl and NO^• biological radicals.

We determined the phytochemical composition, anti-inflammatory mechanism of action, ROS/RNS scavenging capacity and systemic toxicity of a purified subfraction (S8) of Eugenia selloi. The composition of S8 was assessed by LC-ESI-QTOF-MS; the anti-inflammatory activity in RAW264.7 macrophages through NF-κB activation and biomarkers by multiplex in THP-1 cells; neutrophil migration, intravital microscopy and ICAM-1 expression in mice; NETs formation and CD11b expression; S8 scavenging capacity of ROS/RNS; toxicity in Galleria mellonella larvae model. Coumaric acid, quercetrin and vanillic acid were identified. S8 decreased NF-κB activation, IL-1β, IL-6, IL-10, MDC and MCP-1 levels, reduced neutrophil migration and ICAM-1 expression in mice; S8 did not interfere NET formation and CD11b expression, exhibited high antioxidant and showed negligible toxicity. E. selloi proved to be a promising, yet underexplored source of bioactive compounds, which can be useful employed in agribusiness and in the pharmaceutical and food industry to develop new products or human health supplies.

A Study on the Anti-NF-кB, Anti-Candida, and Antioxidant Activities of Two Natural Plant Hormones: Gibberellin A4 and A7

Introduction: Gibberellins (GA) are terpenoids that serve as important plant hormones by acting as growth and response modulators against injuries and parasitism. In this study, we investigated the in vitro anti-NF-κB, anti-Candida, and antioxidant activity of gibberellin A4 (GA4) and A7 (GA7) compounds, and further determined their toxicity in vivo. Methods: GA4 and GA7 in vitro toxicity was determined by MTT method, and nontoxic concentrations were then tested to evaluate the GA4 and GA7 anti-NF-κB activity in LPS-activated RAW-luc macrophage cell culture (luminescence assay). GA4 in silico anti-NF-κB activity was evaluated by molecular docking with the software “AutoDock Vina”, “MGLTools”, “Pymol”, and “LigPlot+”, based on data obtained from “The Uniprot database”, “Protein Data Bank”, and “PubChem database”. The GA4 and GA7 in vitro anti-Candida effects against Candida albicans (MYA 2876) were determined (MIC and MFC). GA7 was also evaluated regarding the viability of C. albicans preformed biofilm (microplate assay). In vitro antioxidant activity of GA4 and GA7 was evaluated against peroxyl radicals, superoxide anions, hypochlorous acid, and reactive nitrogen species. GA4 and GA7 in vivo toxicity was determined on the invertebrate Galleria mellonella larvae model. Results: Our data show that GA4 at 30 µM is nontoxic and capable of reducing 32% of the NF-κB activation on RAW-luc macrophages in vitro. In vitro results were confirmed via molecular docking assay (in silico), since GA4 presented binding affinity to NF-κB p65 and p50 subunits. GA7 did not present anti-NF-κB effects, but exhibited anti-Candida activity with low MIC (94 mM) and MFC (188 mM) values. GA7 also presented antibiofilm properties at 940 mM concentration. GA4 did not present anti-Candida effects. Moreover, GA4 and GA7 showed antioxidant activity against peroxyl radicals, but did not show scavenging activity against the other tested radicals. Both compounds did not affect the survival of G. mellonella larvae, even at extremely high doses (10 g/Kg). Conclusion: Our study provides preclinical evidence indicating that GA4 and GA7 have a favorable low toxicity profile. The study also points to GA4 and GA7 interference with the NF-κB via, anti-Candida activity, and a peroxyl radical scavenger, which we argue are relevant biological effects.

Anti-Adhesion and Antibiofilm Activity of Eruca sativa Miller Extract Targeting Cell Adhesion Proteins of Food-Borne Bacteria as a Potential Mechanism: Combined In Vitro-In Silico Approach

Bacterial cells have the ability to form biofilm onto the surfaces of food matrixes and on food processing equipment, leading to a source of food contamination posing serious health implications. Therefore, our study aimed to determine the effect of Eruca sativa Miller (E. sativa) crude extract against biofilms of food-borne bacteria along with in silico approaches to investigate adhesion proteins responsible for biofilm activity against the identified phytochemicals. The antibacterial potential of crude extract was evaluated using agar well diffusion technique and combinations of light and scanning electron microscopy to assess the efficacy of crude extract against the developed biofilms. Our results showed that crude extract of E. sativa was active against all tested food-borne bacteria, exhibiting a rapid kinetics of killing bacteria in a time-dependent manner. MIC and MBC values of E. sativa crude extract were found to be ranging from 125 to 500 µg/mL and 250 to 1000 µg/mL respectively. Furthermore, inhibition of developed biofilm by E sativa was found to be ranging from 58.68% to 73.45% for all the tested strains. The crude extract also reduced the viability of bacterial cells within biofilms and amount of EPS (ranging 59.73-82.77%) in the biofilm matrix. Additionally, the microscopic images also revealed significant disruption in the structure of biofilms. A molecular docking analysis of E. sativa phytochemicals showed interaction with active site of adhesion proteins Sortase A, EspA, OprD, and type IV b pilin of S. aureus, E. coli, P. aeruginosa, and S. enterica ser. typhi, respectively. Thus, our findings represent the first demonstration of E. sativa crude extract's bioactivity and potency against food-borne bacteria in their planktonic forms, as well as against the developed biofilms. Therefore, a possible mechanistic approach for inhibition of biofilm via targeting adhesion proteins can be explored further to target biofilm producing food-borne bacterial pathogens.

Toxicological Parameters of a Formulation Containing Cinnamaldehyde for Use in Treatment of Oral Fungal Infections: An In Vivo Study

OBJECTIVE

We aimed to define the safety and toxicity of both isolated and embedded cinnamaldehyde using a pharmaceutical formulation for the treatment of oral fungal infections in an in vivo study.

MATERIALS AND METHODS

Acute toxicity was assessed in studies with Galleria mellonella larvae and Danio rerio embryos (zebrafish), and genotoxicity was assessed in a mouse model. The pharmaceutical formulation (orabase ointment) containing cinnamaldehyde was evaluated for verification of both in vitro antifungal activity and toxicity in keratinized oral rat mucosa.

RESULTS

In Galleria mellonella larvae, cinnamaldehyde was not toxic up to the highest dose tested (20 mg/kg) and presented no genotoxicity up to the dose of 4 mg/kg in the model using mice. However, it was found to be toxic in zebrafish embryos up to a concentration of 0.035 μg/mL; LC50 0.311; EC50 0.097 (egg hatching delay); and 0.105 (Pericardial edema). In the orabase antifungal susceptibility test, cinnamaldehyde exhibited activity in concentrations greater than 200 μg/mL. As for safety in the animal model with rats, the orabase ointment proved to be safe for use on keratinized mucosa up to the maximum concentration tested (700 μg/mL).

CONCLUSIONS

At the concentrations tested, cinnamaldehyde was not toxic in vertebrate and invertebrate animal models and did not exhibit genotoxic activity. In addition, when used in the form of an ointment in orabase, having already recognized antifungal activity, it was shown to be safe up to the highest concentration tested.

Fungal Biofilms as a Valuable Target for the Discovery of Natural Products That Cope with the Resistance of Medically Important Fungi-Latest Findings

The development of new antifungal agents that target biofilms is an urgent need. Natural products, mainly from the plant kingdom, represent an invaluable source of these entities. The present review provides an update (2017-May 2021) on the available information on essential oils, propolis, extracts from plants, algae, lichens and microorganisms, compounds from different natural sources and nanosystems containing natural products with the capacity to in vitro or in vivo modulate fungal biofilms. The search yielded 42 articles; seven involved essential oils, two Brazilian propolis, six plant extracts and one of each, extracts from lichens and algae/cyanobacteria. Twenty articles deal with the antibiofilm effect of pure natural compounds, with 10 of them including studies of the mechanism of action and five dealing with natural compounds included in nanosystems. Thirty-seven manuscripts evaluated Candida spp. biofilms and two tested Fusarium and Cryptococcus spp. Only one manuscript involved Aspergillus fumigatus. From the data presented here, it is clear that the search of natural products with activity against fungal biofilms has been a highly active area of research in recent years. However, it also reveals the necessity of deepening the studies by (i) evaluating the effect of natural products on biofilms formed by the newly emerged and worrisome health-care associated fungi, C. auris, as well as on other non-albicans Candida spp., Cryptococcus sp. and filamentous fungi; (ii) elucidating the mechanisms of action of the most active natural products; (iii) increasing the in vivo testing.

Herbal Extracts with Antifungal Activity against Candida albicans: A Systematic Review

In the era of antimicrobial resistance, fungal pathogens are not an exception. Several strategies, including antimicrobial stewardship programs and high throughput screening of new drugs, are being implemented. Several recent studies have demonstrated the effectiveness of plant compounds with antifungal activity. In this systematic review, we examine the use of natural compounds as a possible avenue to fight fungal infections produced by Candida albicans, the most common human fungal pathogen. Electronic literature searches were conducted through PubMed/MEDLINE, Cochrane, and Science Direct limited to the 5 years. A total of 131 articles were included, with 186 plants extracts evaluated. Although the majority of the natural extracts exhibited antifungal activities against C. albicans (both in vivo and in vitro), the strongest antifungal activity was obtained from Lawsonia inermis, Pelargonium graveolens, Camellia sinensis, Mentha piperita, and Citrus latifolia. The main components with proven antifungal activities were phenolic compounds such as gallic acid, thymol, and flavonoids (especially catechin), polyphenols such as tannins, terpenoids and saponins. The incorporation of nanotechnology greatly enhances the antifungal properties of these natural compounds. Further research is needed to fully characterize the composition of all herbal extracts with antifungal activity as well as the mechanisms of action of the active compounds.

Plant Preparations and Compounds with Activities against Biofilms Formed by Candida spp

Fungi from the genus Candida are very important human and animal pathogens. Many strains can produce biofilms, which inhibit the activity of antifungal drugs and increase the tolerance or resistance to them as well. Clinically, this process leads to persistent infections and increased mortality. Today, many Candida species are resistant to drugs, including C. auris, which is a multiresistant pathogen. Natural compounds may potentially be used to combat multiresistant and biofilm-forming strains. The aim of this review was to present plant-derived preparations and compounds that inhibit Candida biofilm formation by at least 50%. A total of 29 essential oils and 16 plant extracts demonstrate activity against Candida biofilms, with the following families predominating: Lamiaceae, Myrtaceae, Asteraceae, Fabaceae, and Apiacae. Lavandula dentata (0.045-0.07 mg/L), Satureja macrosiphon (0.06-8 mg/L), and Ziziphora tenuior (2.5 mg/L) have the best antifungal activity. High efficacy has also been observed with Artemisia judaica, Lawsonia inermis, and Thymus vulgaris. Moreover, 69 plant compounds demonstrate activity against Candida biofilms. Activity in concentrations below 16 mg/L was observed with phenolic compounds (thymol, pterostilbene, and eugenol), sesquiterpene derivatives (warburganal, polygodial, and ivalin), chalconoid (lichochalcone A), steroidal saponin (dioscin), flavonoid (baicalein), alkaloids (waltheriones), macrocyclic bisbibenzyl (riccardin D), and cannabinoid (cannabidiol). The above compounds act on biofilm formation and/or mature biofilms. In summary, plant preparations and compounds exhibit anti-biofilm activity against Candida. Given this, they may be a promising alternative to antifungal drugs.

Natural Anti-biofilm Agents: Strategies to Control Biofilm-Forming Pathogens

Pathogenic microorganisms and their chronic pathogenicity are significant concerns in biomedical research. Biofilm-linked persistent infections are not easy to treat due to resident multidrug-resistant microbes. Low efficiency of various treatments and in vivo toxicity of available antibiotics drive the researchers toward the discovery of many effective natural anti-biofilm agents. Natural extracts and natural product-based anti-biofilm agents are more efficient than the chemically synthesized counterparts with lesser side effects. The present review primarily focuses on various natural anti-biofilm agents, i.e., phytochemicals, biosurfactants, antimicrobial peptides, and microbial enzymes along with their sources, mechanism of action via interfering in the quorum-sensing pathways, disruption of extracellular polymeric substance, adhesion mechanism, and their inhibitory concentrations existing in literature so far. This study provides a better understanding that a particular natural anti-biofilm molecule exhibits a different mode of actions and biofilm inhibitory activity against more than one pathogenic species. This information can be exploited further to improve the therapeutic strategy by a combination of more than one natural anti-biofilm compounds from diverse sources.

Phenolic profile and potential beneficial effects of underutilized Brazilian native fruits on scavenging of ROS and RNS and anti-inflammatory and antimicrobial properties

Brazilian native fruits (BNF) have aroused interest of researchers and consumers for their great human health benefits. In this study, five BNF (Byrsonima lancifolia, Campomanesia phaea, Jacaratia spinosa, Solanum alternatopinnatum and Acnistus arborescens) were tested for their polyphenolic compounds by LC-ESI-MS/MS, reactive species deactivation (ROO˙, O2˙-, HOCl and NO˙), anti-inflammatory properties in vivo, and in vitro antimicrobial activity - with determination of putative mechanism(s) of action. Eighty-one polyphenols were identified, which exhibited a significant capacity to deactivate both ROS and RNS. C. phaea extract had the highest capacity to scavenge ROO˙ (68.94 μmol TE per g), O2˙- (IC50: 575.36 μg mL-1) and NO˙ (IC50: 16.96 μg mL-1), which may be attributed to the presence of ellagitanins. B. lancifolia decreased neutrophil influx into the peritoneal cavity of mice by 50% as compared to carrageenan and reduced Candida albicans biofilm viability by 3 log10 possibly due to complexation with cell membrane ergosterol. In summary, the BNF presented herein are good sources of bioactive compounds with positive effects on deactivation of biological reactive species, as well as with anti-inflammatory and antimicrobial activities, which can be altogether highly beneficial to human health.

Synthesis, structural characterization, and prospects for new cobalt (II) complexes with thiocarbamoyl-pyrazoline ligands as promising antifungal agents

Candida spp. cause invasive fungal infections. One species, Candida glabrata, may present intrinsic resistance to conventional antifungal agents, thereby increasing mortality rates in hospitalized patients. In this context, metal complexes present an alternative for the development of new antifungal drugs owing to their biological and pharmacological activities demonstrated in studies in the last decades. Accordingly, in this study we have synthesized and characterized two new Co(II) complexes with thiocarbamoyl-pyrazoline ligands to assess their antimicrobial, mutagenic, and cytotoxic potential. For antimicrobial activity, the broth microdilution method was performed against ATCC strains of Candida spp. and fluconazole dose-dependent isolates of C. glabrata obtained from urine samples. The Ames test was used to assess mutagenic potential. The reduction method of the MTS reagent (3 [4,5-dimethylthiazol-2-yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2H-tetrazolium) was performed with HeLa, SiHa, and Vero cells to determine cytotoxicity. Both complexes exhibited fungistatic and fungicidal activity for the yeasts used in the study, demonstrating greater potential for C. glabrata ATCC 2001 and the C. glabrata CG66 isolate with a Minimum Inhibitory Concentration MIC from 3.90 to 7.81 μg mL^-1 and fungicidal action from 7.81 to 15.62 μg mL^-1. The complexes inhibited and degraded biofilms by up to 90% and did not present mutagenic and cytotoxic potential at the concentrations evaluated for MIC. Thus, the complexes examined herein suggest promising alternatives for the development of new antifungal drugs.

N4 -benzyl-N2 -phenylquinazoline-2,4-diamine compound presents antibacterial and antibiofilm effect against Staphylococcus aureus and Staphylococcus epidermidis

Staphylococcus aureus and Staphylococcus epidermidis are the main agents involved with implant-related infections. Their ability to adhere to medical devices with subsequent biofilm formation is crucial to the development of these infections. Herein, we described the antibacterial and antibiofilm activities of a quinazoline-based compound, N₄ -benzyl-N₂ -phenylquinazoline-2,4-diamine, against both biofilm-forming pathogens. The minimum inhibitory concentrations (MIC) were determined as 25 µM for S. aureus and 15 µM for S. epidermidis. At sub-MIC concentrations (20 µM for S. aureus and 10 µM for S. epidermidis), the compound was able to inhibit biofilm formation without interfere with bacterial growth, confirmed by scanning electron microscopy. Moreover, surfaces coated with the quinazoline-based compound were able to prevent bacterial adherence. In addition, this compound presented no toxicity to human red blood cells at highest MIC 25 µM and in vivo toxicity assay using Galleria mellonella larvae resulted in 82% survival with a high dose of 500 mg/kg body weight. These features evidence quinazoline-based compound as interesting entities to promising applications in biomedical fields, such as antimicrobial and in anti-infective approaches.

Anti-inflammatory and antioxidant potential, in vivo toxicity, and polyphenolic composition of Eugenia selloi B.D.Jacks. (pitangatuba), a Brazilian native fruit

Brazilian native fruits are a rich source of polyphenolic compounds that can act as anti-inflammatory and antioxidant agents. Here, we determined the polyphenolic composition, anti-inflammatory mechanism of action, antioxidant activity and systemic toxicity in Galleria mellonella larvae of Eugenia selloi B.D.Jacks. (synonym Eugenia neonitida Sobral) extract (Ese) and its polyphenol-rich fraction (F3) obtained through bioassay-guided fractionation. Phenolic compounds present in Ese and F3 were identified by LC-ESI-QTOF-MS. The anti-inflammatory activity of Ese and F3 was tested in vitro and in vivo through NF-κB activation, cytokine release and neutrophil migration assays. The samples were tested for their effects against reactive species (ROO•, O2•-, HOCl and NO•) and for their toxicity in Galleria mellonella larvae model. The presence of hydroxybenzoic acid, ellagitannins and flavonoids was identified. Ese and F3 reduced NF-κB activation, cytokine release and neutrophil migration, with F3 being three-fold more potent. Overall, F3 exhibited strong antioxidant effects against biologically relevant radicals, and neither Ese nor F3 were toxic to G. mellonella larvae. In conclusion, Ese and F3 revealed the presence of phenolic compounds that decreased the inflammatory parameters evaluated and inhibited reactive oxygen/nitrogen species. E. selloi is a novel source of bioactive compounds that may provide benefits for human health.

Effect of Adiantum philippense Extract on Biofilm Formation, Adhesion With Its Antibacterial Activities Against Foodborne Pathogens, and Characterization of Bioactive Metabolites: An in vitro-in silico Approach

Adiantum philippense (A. philippense), an ethnomedicinally important fern, has become an interesting herb in the search for novel bioactive metabolites, which can also be used as therapeutic agents. Primarily, in this study, A. philippense crude extract was screened for its phytochemical constituents, antagonistic potential, and effect on bacterial adhesion and biofilm formation against common food pathogens. Phytochemical profiling of A. philippense was carried out by using High Resolution-Liquid Chromatography and Mass Spectroscopy (HR-LCMS) followed by antibacterial activity via agar cup/well diffusion, broth microdilution susceptibility methods, and growth curve analysis. Antibiofilm potency and efficacy were assessed on the development, formation, and texture of biofilms through light microscopy, fluorescent microscopy, scanning electron microscopy, and the assessment of exopolysaccharide production. Correspondingly, a checkerboard test was performed to evaluate the combinatorial effect of A. philippense and chloramphenicol. Lastly, molecular docking studies of identified phytochemicals with adhesin proteins of tested food pathogens, which helps the bacteria in surface attachment and leads to biofilm formation, were assessed. A. philippense crude extract was found to be active against all tested food pathogens, displaying the rapid time-dependent kinetics of bacterial killing. A. philippense crude extract also impedes the biofilm matrix by reducing the total content of exopolysaccharide, and, likewise, the microscopic images revealed a great extent of disruption in the architecture of biofilms. A synergy was observed between A. philippense crude extract and chloramphenicol for E. coli, S. aureus, and P. aeruginosa, whereas an additive effect was observed for S. flexneri. Various bioactive phytochemicals were categorized from A. philippense crude extract using HR-LCMS. The molecular docking of these identified phytochemicals was interrelated with the active site residues of adhesin proteins, IcsA, Sortase A, OprD, EspA, and FimH from S. flexneri, S. aureus, P. aeruginosa, and E. coli, respectively. Thus, our findings represent the bioactivity and potency of A. philippense crude extract against food pathogens not only in their planktonic forms but also against/in biofilms for the first time. We have also correlated these findings with the possible mechanism of biofilm inhibition via targeting adhesin proteins, which could be explored further to design new bioactive compounds against biofilm producing foodborne bacterial pathogens.

Anti-inflammatory and anti-Candida Effects of Brazilian Organic Propolis, a Promising Source of Bioactive Molecules and Functional Food

Brazilian organic propolis (BOP) is an unexplored Brazilian propolis that is produced organically and certified according to international legislation. Our results showed that BOP has strong anti-inflammatory effects and acts by reducing nuclear factor κB activation, tumor necrosis factor α release, and neutrophil migration. In addition, BOP6 exhibited antifungal activity on planktonic and biofilm cultures of Candida albicans, Candida glabrata, Candida tropicalis, Candida krusei, and Candida parapsisolis and reduced in vitro yeast cell adhesion to human keratinocytes at sub-inhibitory concentrations. BOP demonstrated significantly low toxicity in Galleria melonella larvae at antifungal doses. Lastly, a chemical analysis revealed the presence of caffeoyltartaric acid, 3,4-dicaffeoylquinic acid, quercetin, and gibberellins A7, A9, and A20, which may be responsible for the biological properties observed. Thus, our data indicate that BOP is a promising source of anti-inflammatory and antifungal molecules that may be used as a functional food.

Cytotoxic Action of Artemisinin and Scopoletin on Planktonic Forms and on Biofilms of Candida Species

We investigated the antifungal activities of purified plant metabolites artemisinin (Ar) and scopoletin (Sc) including inhibition, effects on metabolic activities, viability, and oxidative stress on planktonic forms and on preformed biofilms of seven Candida species. The characteristic minimum inhibitory concentration (MIC90) of Ar and Sc against Candida species ranged from 21.83-142.1 µg/mL and 67.22-119.4 µg/mL, respectively. Drug concentrations causing ≈10% CFU decrease within 60 minutes of treatments were also determined (minimum effective concentration, MEC10) using 100-fold higher CFUs than in the case of MIC90 studies. Cytotoxic effects on planktonic and on mature biofilms of Candida species at MEC10 concentrations were further evaluated with fluorescent live/dead discrimination techniques. Candida glabrata, Candida guilliermondii, and Candida parapsilosis were the species most sensitive to Ar and Sc. Ar and Sc were also found to promote the accumulation of intracellular reactive oxygen species (ROS) by increasing oxidative stress at their respective MEC10 concentrations against the tested planktonic Candida species. Ar and Sc possess dose-dependent antifungal action but the underlying mechanism type (fungistatic and fungicidal) is not clear yet. Our data suggest that Ar and Sc found in herbal plants might have potential usage in the fight against Candida biofilms.