Optimization of Phenolic-Enriched Extracts from Olive Leaves via Ball Milling-Assisted Extraction Using Response Surface Methodology.

This study aims to extract phenolic-enriched compounds, specifically oleuropein, luteoloside, and hydroxytyrosol, from olive leaves using ball milling-assisted extraction (BMAE). Response surface methodology (RSM) and the Box-Behnken design (BBD) were used to evaluate the effects of the temperature, solvent-to-solid ratio, and milling speed on extraction recovery. The contents of the extract were determined by ultra-high-performance liquid chromatography-mass spectrometry (UPLC-MS) and converted to recoveries to evaluate the extraction efficiency. The optimal extraction conditions for oleuropein, luteoloside, and hydroxytyrosol were identified. Oleuropein had a recovery of 79.0% ± 0.9% at a temperature of 56.4 °C, a solvent-to-solid ratio of 39.1 mL/g, and a milling speed of 429 rpm. Luteoloside's recovery was 74.6% ± 1.2% at 58.4 °C, 31.3 mL/g, and 328 rpm. Hydroxytyrosol achieved 43.1% ± 1.3% recovery at 51.5 °C, 32.7 mL/g, and 317 rpm. The reason for the high recoveries might be that high energy ball milling could reduce the sample size further, breaking down the cell walls of olive leaves, to enhance the mass transfer of these components from the cell to solvent. BMAE is displayed to be an efficient approach to extracting oleuropein, luteoloside, and hydroxytyrosol from olive leaves, which is easy to extend to industrial production.

Flow and On-Water Synthesis and Cancer Cell Cytotoxicity of Caffeic Acid Phenethyl Amide (CAPA) Derivatives.

Caffeic acid phenethyl ester (CAPE) is a phenolic natural product with a wide range of biological activities, including anticancer activity; however, the ester group of CAPE is metabolically labile. The corresponding amide, CAPA, has improved metabolic stability but limited anticancer activity relative to CAPE. We report the synthesis using flow and on-water Wittig reaction approaches of five previously reported and five novel CAPA analogues. All of these analogues lack the reactive catechol functionality of CAPA and CAPE. Cytotoxicity studies of CAPE, CAPA, and these CAPA analogues in HeLa and BE(2)-C cells were carried out. Surprisingly, we found that CAPA is cytotoxic against the neuroblastoma BE(2)-C cell line (IC50 = 12 µM), in contrast to the weak activity of CAPA against HeLa cells (IC50 = 112 µM), and the literature reports of the absence of activity for CAPA against a variety of other cancer cell lines. One novel CAPA analogue, 3f, was identified as having cytotoxic activity similar to CAPE in HeLa cells (IC50 = 63 µM for 3f vs. 32 µM for CAPE), albeit with lower activity against BE(2)-C cells (IC50 = 91 µM) than CAPA. A different CAPA analogue, 3g, was found to have similar effects against BE(2)-C cells (IC50 = 92 µM). These results show that CAPA is uniquely active against neuroblastoma cells and that specific CAPA analogues that are predicted to be more metabolically stable than CAPE can reproduce CAPA's activity against neuroblastoma cells and CAPE's activity against HeLa cells.

Hydroxytyrosol permeability comparisons and strategies to improve hydroxytyrosol stability in formulations.

There has been a growing interest in hydroxytyrosol (HT) due to its powerful antioxidant and free-radical scavenging properties when added to formulations such as pharmaceuticals and cosmetics. To study the stability and transdermal properties of hydrogels and creams (HT-based formulations), a high-performance liquid chromatography method was developed for determining HT. In the Franz diffusion cell system, both hydrogel and cream show a rapid and similar penetration profile through the Bama miniature pig skin. However, the Strat-M® membrane exhibits slightly lower permeability and is selective to different formulations; that is, the cream has a permeability value of 10.69%, while the hydrogel has a value of 5.27%. The dynamics parameters from the permeation assays indicate that the model using the Strat-M® membrane can be used as a screening tool to evaluate the skin uptake and permeation efficacy of different formulations. Adding 3-O-ethyl-L-ascorbic acid to HT-based formulations can effectively prevent discoloration under prolonged high-temperature storage, while combining multiple antioxidants delays degradation most effectively. This study provides novel ideas for functional formulation optimization to enhance the realism and reproducibility of cosmetic products containing HT and provides scientific evidence for the production, packaging, shelf life, storage, and transportation of products.

Effect of Hanseniaspora vineae and Saccharomyces cerevisiae co-fermentations on aroma compound production in beer.

In recent years, the boom of the craft beer industry refocused the biotech interest from ethanol production to diversification of beer aroma profiles. This study analyses the fermentative phenotype of a collection of non-conventional yeasts and examines their role in creating new flavours, particularly through co-fermentation with industrial Saccharomyces cerevisiae. High-throughput solid and liquid media fitness screening compared the ability of eight Saccharomyces and four non-Saccharomyces yeast strains to grow in wort. We determined the volatile profile of these yeast strains and found that Hanseniaspora vineae displayed a particularly high production of the desirable aroma compounds ethyl acetate and 2-phenethyl acetate. Given that H. vineae on its own can't ferment maltose and maltotriose, we carried out mixed wort co-fermentations with a S. cerevisiae brewing strain at different ratios. The two yeast strains were able to co-exist throughout the experiment, regardless of their initial inoculum, and the increase in the production of the esters observed in the H. vineae monoculture was maintained, alongside with a high ethanol production. Moreover, different inoculum ratios yielded different aroma profiles: the 50/50 S. cerevisiae/H. vineae ratio produced a more balanced profile, while the 10/90 ratio generated stronger floral aromas. Our findings show the potential of using different yeasts and different inoculum combinations to tailor the final aroma, thus offering new possibilities for a broader range of beer flavours and styles.

Novel Saccharomyces uvarum x Saccharomyces kudriavzevii synthetic hybrid with enhanced 2-phenylethanol production.

BACKGROUND: Over the last two decades, hybridization has been a powerful tool used to construct superior yeast for brewing and winemaking. Novel hybrids were primarily constructed using at least one Saccharomyces cerevisiae parent. However, little is known about hybrids used for other purposes, such as targeted flavor production, for example, 2-phenylethanol (2-PE). 2-PE, an aromatic compound widely utilised in the food, cosmetic, and pharmaceutical industries, presents challenges in biotechnological production due to its toxic nature. Consequently, to enhance productivity and tolerance to 2-PE, various strategies such as mutagenesis and genetic engineering are extensively explored to improved yeast strains. While biotechnological efforts have predominantly focused on S. cerevisiae for 2-PE production, other Saccharomyces species and their hybrids remain insufficiently described. RESULTS: To address this gap, in this study, we analysed a new interspecies yeast hybrid, II/6, derived from S. uvarum and S. kudriavzevii parents, in terms of 2-PE bioconversion and resistance to its high concentration, comparing it with the parental strains. Two known media for 2-PE biotransformation and three different temperatures were used during this study to determine optimal conditions. In 72 h batch cultures, the II/6 hybrid achieved a maximum of 2.36 ± 0.03 g/L 2-PE, which was 2-20 times higher than the productivity of the parental strains. Our interest lay not only in determining whether the hybrid improved in productivity but also in assessing whether its susceptibility to high 2-PE titers was also mitigated. The results showed that the hybrid exhibited significantly greater resistance to the toxic product than the original strains. CONCLUSIONS: The conducted experiments have confirmed that hybridization is a promising method for modifying yeast strains. As a result, both 2-PE production yield and tolerance to its inhibitory effects can be increased. Furthermore, this strategy allows for the acquisition of non-GMO strains, alleviating concerns related to additional legislative requirements or consumer acceptance issues for producers. The findings obtained have the potential to contribute to the development of practical solutions in the future.

Enhancing Bioactivity through the Transfer of the 2-(Hydroxymethoxy)Vinyl Moiety: Application in the Modification of Tyrosol and Hinokitiol.

Utilizing Density Functional Theory (DFT) calculations at the B3LYP/QZVP level and incorporating the Conductor-like Polarizable Continuum Model (C-PCM) for solvation, the thermodynamic and chemical activity properties of 21-(hydroxymethoxy)henicosadecaenal, identified in cultured freshwater pearls from the mollusk Hyriopsis cumingii, have been elucidated. The study demonstrates that this compound releases formaldehyde, a potent antimicrobial agent, through dehydrogenation and deprotonation processes in both hydrophilic and lipophilic environments. Moreover, this polyenal exhibits strong anti-reductant properties, effectively scavenging free radicals. These critical properties classify the pearl-derived ingredient as a natural multi-functional compound, serving as a coloring, antiradical, and antimicrobial agent. The 2-(hydroxymethoxy)vinyl (HMV) moiety responsible for the formaldehyde release can be transferred to other compounds, thereby enhancing their biological activity. For instance, tyrosol (4-(2-hydroxyethyl)phenol) can be modified by substituting the less active 2-hydroxyethyl group with the active HMV one, and hinokitiol (4-isopropylotropolone) can be functionalized by attaching this moiety to the tropolone ring. A new type of meso-carrier, structurally modeled on pearls, with active substances loaded both in the layers and the mineral part, has been proposed.

Tyrosol blocks E. coli anaerobic biofilm formation via YbfA and FNR to increase antibiotic susceptibility.

Bacteria within mature biofilms are highly resistant to antibiotics than planktonic cells. Oxygen limitation contributes to antibiotic resistance in mature biofilms. Nitric oxide (NO) induces biofilm dispersal; however, low NO levels stimulate biofilm formation, an underexplored process. Here, we introduce a mechanism of anaerobic biofilm formation by investigating the antibiofilm activity of tyrosol, a component in wine. Tyrosol inhibits E. coli and Pseudomonas aeruginosa biofilm formation by enhancing NO production. YbfA is identified as a target of tyrosol and its downstream targets are sequentially determined. YbfA activates YfeR, which then suppresses the anaerobic regulator FNR. This suppression leads to decreased NO production, elevated bis-(3'-5')-cyclic dimeric GMP levels, and finally stimulates anaerobic biofilm formation in the mature stage. Blocking YbfA with tyrosol treatment renders biofilm cells as susceptible to antibiotics as planktonic cells. Thus, this study presents YbfA as a promising antibiofilm target to address antibiotic resistance posed by biofilm-forming bacteria, with tyrosol acting as an inhibitor.

Comparative study of Spanish-style and natural cv. Chalkidiki green olives throughout industrial-scale spontaneous fermentation and 12-month storage: safety, nutritional and quality aspects.

Table olives are among the most popular fermented foods and cv. Chalkidiki green table olives are particularly popular in both Greek and international markets. This work aimed at comparatively investigating the effect of processing method on the production of Spanish-style and natural cv. Chalkidiki green olives during fermentation and 12-month storage in brines with different chloride salts composition (NaCl, KCl, CaCl2) at industrial scale. All delivered products were safe with satisfactory color and texture characteristics. Employment of UPLC-HRMS revealed differences in metabolites' profile of polar extracts from olives and brines between the processing methods. Τhe application of alkali treatment drastically decreased the content of hydroxytyrosol and tyrosol in drupes, still an essential amount (1037-2012 and 385-885 mg/kg dry flesh, respectively) of these health-promoting phenolic compounds was retained in all products, even after storage. Noteworthy, fermentation of natural olives in brine (5 % NaCl) yielded in products with significantly lower Na levels in olive flesh (1.7 g/100 g), followed by Spanish-style olives fermented in low (4 %) and high (8 %) NaCl brines (2.7 and 5.2 g Na/100 g, respectively), supporting the efforts toward the establishment of table olives as functional food. Moreover, maslinic and oleanolic acids content was 1.5-2-fold higher in the natural table olives compared to the Spanish-style ones owing to the detrimental effect of alkali treatments. The processing method did not exert a differential effect on α-tocopherol content of olives. Sensory analysis indicated that all the final products were acceptable by consumers, with a slight preference for Spanish-style green olives fermented in brines with 50 % lower NaCl content. Present findings could be beneficial to the ongoing endeavor directed for the establishment of table olives as a source of bioactive compounds that concerns both industrial and scientific communities.

Exploring rose absolute and phenylethyl alcohol as novel quorum sensing inhibitors in Pseudomonas aeruginosa and Chromobacterium violaceum.

Inter-cellular signaling, referred to as quorum sensing (QS), regulates the production of virulence factors in numerous gram-negative bacteria, such as the human pathogens Pseudomonas aeruginosa and Chromobacterium violaceum. QS inhibition may provide an opportunity for the treatment of bacterial infections. This represents the initial study to examine the antibiofilm and antivirulence capabilities of rose absolute and its primary component, phenylethyl alcohol. QS inhibition was assessed by examining extracellular exopolysaccharide synthesis, biofilm development, and swarming motility in P. aeruginosa PAO1, along with violacein production in C. violaceum ATCC 12472. Molecular docking analysis was conducted to explore the mechanism by which PEA inhibits QS. Our results indicate that rose absolute and PEA caused decrease in EPS production (60.5-33.5%), swarming motility (94.7-64.5%), and biofilm formation (98.53-55.5%) in the human pathogen P. aeruginosa PAO1. Violacein production decreased by 98.1% and 62.5% with an absolute (0.5 v/v %) and PEA (2 mM). Moreover, the molecular docking analysis revealed a promising competitive interaction between PEA and AHLs. Consequently, this study offers valuable insights into the potential of rose absolute and PEA as inhibitors of QS in P. aeruginosa and C. violaceum.

[Investigation of the inhibitory potential of caffeic acid phenethyl ester on prion replication, amplification, and fibril formation in vitro].

Objective: To investigate the effects and possible mechanisms of caffeic acid phenethyl ester (CAPE) on the replication, amplification, and fibre formation of prions (PrPSc). Methods: The CCK8 assay was used to detect the cell viability of the prion-infected cell model SMB-S15 after CAPE treatment for 3 days and 7 days and the maximum safe concentration of CAPE for SMB-S15 was obtained. The cells were treated with a concentration within a safe range, and the content of PrPSc in the cells before and after CAPE treatment was analyzed by western blot. Protein misfolding cycle amplification (PMCA) and western blot were used to assess changes in PrPSc level in amplification products following CAPE treatment. Real-time-quaking induced conversion assay (RT-QuIC) technology was employed to explore the changes in fibril formation before and after CAPE treatment. The binding affinity between CAPE and murine recombinant full-length prion protein was determined using a molecular interaction assay. Results: CCK8 cell viability assay results demonstrated that treatment with 1 µmol/L CAPE for 3 and 7 days did not exhibit statistically significant differences in cell viability compared to the control group (all P<0.05). However, when the concentration of CAPE exceeded 1 µmol/L, a significant reduction in cell viability was observed in cells treated with CAPE for 3 and 7 days, compared to the control group (all P<0.05). Thus, 1 µmol/L was determined as the maximum safe concentration of CAPE treatment for SMB-S15 cells. The western blot results revealed that treatment with CAPE for both 3 and 7 days led to a detectable reduction in the levels of PrPSc in SMB-S15 cells (all P<0.05). The products of PMCA experiments were assessed using western blot. The findings revealed a significant decrease in the levels of PrPSc (relative grey value) in the PMCA amplification products of adapted-strains SMB-S15, 139A, and ME7 following treatment with CAPE, as compared to the control group (all P<0.05). The RT-QuIC experimental results demonstrated a reduction in fibril formation (as indicated by ThT peak values) in CAPE-treated mouse-adapted strains 139A, ME7, and SMB-S15, as well as in SMB-S15 cells infected with prions. Furthermore, CAPE exhibited varying degrees of inhibition towards different seed fibrils formation, with statistically significant differences observed (all P<0.05). Notably, CAPE exhibited a more pronounced inhibitory effect on ME7 seed fibrils. Molecular interaction analyses demonstrated significant binding between CAPE and murine recombinant prion protein, and the association constant was (2.92±0.41)×10-6 mol/L. Conclusions: CAPE inhibits PrPSc replication, amplification, and fibril formation in vitro possibly due to specific interactions with the prion protein at the molecular level.

Tyrosol-gold nanoparticle functionalized acacia gum-PVA nanofibers for mitigation of Candida biofilm.

Increasing incidences of fungal infections and prevailing antifungal resistance in healthcare settings has given rise to an antifungal crisis on a global scale. The members of the genus Candida, owing to their ability to acquire sessile growth, are primarily associated with superficial to invasive fungal infections, including the implant-associated infections. The present study introduces a novel approach to combat the sessile/biofilm growth of Candida by fabricating nanofibers using a nanoencapsulation approach. This technique involves the synthesis of tyrosol (TYS) functionalized chitosan gold nanocomposite, which is then encapsulated into PVA/AG polymeric matrix using electrospinning. The FESEM, FTIR analysis of prepared TYS-AuNP@PVA/AG NF suggested the successful encapsulation of TYS into the nanofibers. Further, the sustained and long-term stability of TYS in the medium was confirmed by drug release and storage stability studies. The prepared nanomats can absorb the fluid, as evidenced by the swelling index of the nanofibers. The growth and biofilm inhibition, as well as the disintegration studies against Candida, showed 60-70 % biofilm disintegration when 10 mg of TYS-AuNP@PVA/AG NF was used, hence confirming its biological effectiveness. Subsequently, the nanofibers considerably reduced the hydrophobicity index and ergosterol content of the treated cells. Considering the challenges associated with the inhibition/disruption of fungal biofilm, the fabricated nanofibers prove their effectiveness against Candida biofilm. Therefore, nanocomposite-loaded nanofibers have emerged as potential materials that can control fungal colonization and could also promote healing.

Evaluation of Aromatic Characteristics and Potential Applications of Hemerocallis L. Based on the Analytic Hierarchy Process.

Hemerocallis L. possesses abundant germplasm resources and holds significant value in terms of ornamental, edible, and medicinal aspects. However, the quality characteristics vary significantly depending on different varieties. Selection of a high-quality variety with a characteristic aroma can increase the economic value of Hemerocallis flowers. The analytic hierarchy process (AHP) is an effective decision-making method for comparing and evaluating multiple characteristic dimensions. By applying AHP, the aromatic character of 60 varieties of Hemerocallis flowers were analyzed and evaluated in the present study. Headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) was employed to identify volatile components in Hemerocallis flowers. Thirteen volatile components were found to contribute to the aroma of Hemerocallis flowers, which helps in assessing their potential applications in essential oil, aromatherapy, and medical treatment. These components include 2-phenylethanol, geraniol, linalool, nonanal, decanal, (E)-ß-ocimene, α-farnesene, indole, nerolidol, 3-furanmethanol, 3-carene, benzaldehyde and benzenemethanol. The varieties with better aromatic potential can be selected from a large amount of data using an AHP model. This study provides a comprehensive understanding of the characteristics of the aroma components in Hemerocallis flowers, offers guidance for breeding, and enhances the economic value of Hemerocallis flowers.

Hydroxytyrosol Alleviates Intestinal Oxidative Stress by Regulating Bile Acid Metabolism in a Piglet Model.

Infants and young animals often suffer from intestinal damage caused by oxidative stress, which may adversely affect their overall health. Hydroxytyrosol, a plant polyphenol, has shown potential in decreasing intestinal oxidative stress, but its application and mechanism of action in infants and young animals are still inadequately documented. This study selected piglets as a model to investigate the alleviating effects of hydroxytyrosol on intestinal oxidative stress induced by diquat and its potential mechanism. Hydroxytyrosol improved intestinal morphology, characterized by higher villus height and villus height/crypt depth. Meanwhile, hydroxytyrosol led to higher expression of Occludin, MUC2, Nrf2, and its downstream genes, and lower expression of cytokines IL-1ß, IL-6, and TNF-α. Both oxidative stress and hydroxytyrosol resulted in a higher abundance of Clostridium_sensu_stricto_1, and a lower abundance of Lactobacillus and Streptococcus, without a significant effect on short-chain fatty acids levels. Oxidative stress also led to disorders in bile acid (BA) metabolism, such as the lower levels of primary BAs, hyocholic acid, hyodeoxycholic acid, and tauroursodeoxycholic acid, which were partially restored by hydroxytyrosol. Correlation analysis revealed a positive correlation between these BA levels and the expression of Nrf2 and its downstream genes. Collectively, hydroxytyrosol may reduce oxidative stress-induced intestinal damage by regulating BA metabolism.

Caffeic acid phenethyl ester derivative exerts remarkable anti-hepatocellular carcinoma effect, non-inferior to sorafenib, in vivo analysis.

Caffeic acid phenethyl ester (CAPE) and its derivatives exhibit considerable effects against hepatocellular carcinoma (HCC), with unquestioned safety. Here we investigated CAPE derivative 1' (CAPE 1') monotherapy to HCC, compared with sorafenib. HCC Bel-7402 cells were treated with CAPE 1', the IC50 was detected using CCK-8 analysis, and acute toxicity testing (5 g/kg) was performed to evaluate safety. In vivo, tumor growth after CAPE 1' treatment was evaluated using an subcutaneous tumor xenograft model. Five groups were examined, with group 1 given vehicle solution, groups 2, 3, and 4 given CAPE 1' (20, 50, and 100 mg/kg/day, respectively), and group 5 given sorafenib (30 mg/kg/day). Tumor volume growth and tumor volume-to-weight ratio were calculated and statistically analyzed. An estimated IC50 was 5.6 µM. Acute toxicity tests revealed no animal death or visible adverse effects with dosage up to 5 g/kg. Compared to negative controls, CAPE 1' treatment led to significantly slower increases of tumor volume and tumor volume-to-weight. CAPE 1' and sorafenib exerted similar inhibitory effects on HCC tumors. CAPE 1' was non-inferior to sorafenib for HCC treatment, both in vitro and in vivo. It has great potential as a promising drug for HCC, based on effectiveness and safety profile.

Caffeic acid phenethyl ester promotes oxaliplatin sensitization in colon cancer by inhibiting autophagy.

Colon cancer ranks as the third most prevalent form of cancer globally, with chemotherapy remaining the primary treatment modality. To mitigate drug resistance and minimize adverse effects associated with chemotherapy, selection of appropriate adjuvants assumes paramount importance. Caffeic acid phenethyl ester (CAPE), a naturally occurring compound derived from propolis, exhibits a diverse array of biological activities. We observed that the addition of CAPE significantly augmented the drug sensitivity of colon cancer cells to oxaliplatin. In SW480 and HCT116 cells, oxaliplatin combined with 10 µM CAPE reduced the IC50 of oxaliplatin from 14.24 ± 1.03 and 84.16 ± 3.02 µM to 2.11 ± 0.15 and 3.92 ± 0.17 µM, respectively. We then used proteomics to detect differentially expressed proteins in CAPE-treated SW480 cells and found that the main proteins showing changes in expression after CAPE treatment were p62 (SQSTM1) and LC3B (MAP1LC3B). Gene ontology analysis revealed that CAPE exerted antitumor and chemotherapy-sensitization effects through the autophagy pathway. We subsequently verified the differentially expressed proteins using immunoblotting. Simultaneously, the autophagy inhibitor bafilomycin A1 and the mCherry-EGFP-LC3 reporter gene were used as controls to detect the effect of CAPE on autophagy levels. Collectively, the results indicate that CAPE may exert antitumor and chemotherapy-sensitizing effects by inhibiting autophagy, offering novel insights for the development of potential chemosensitizing agents.

Multienzymatic Cascade for Synthesis of Hydroxytyrosol via Two-Stage Biocatalysis.

Hydroxytyrosol, a naturally occurring compound with antioxidant and antiviral activity, is widely applied in the cosmetic, food, and nutraceutical industries. The development of a biocatalytic approach for producing hydroxytyrosol from simple and readily accessible substrates remains a challenge. Here, we designed and implemented an effective biocatalytic cascade to obtain hydroxytyrosol from 3,4-dihydroxybenzaldehyde and l-threonine via a four-step enzymatic cascade composed of seven enzymes. To prevent cross-reactions and protein expression burden caused by multiple enzymes expressed in a single cell, the designed enzymatic cascade was divided into two modules and catalyzed in a stepwise manner. The first module (FM) assisted the assembly of 3,4-dihydroxybenzaldehyde and l-threonine into (2S,3R)-2-amino-3-(3,4-dihydroxyphenyl)-3-hydroxypropanoic acid, and the second module (SM) entailed converting (2S,3R)-2-amino-3-(3,4-dihydroxyphenyl)-3-hydroxypropanoic acid into hydroxytyrosol. Each module was cloned into Escherichia coli BL21 (DE3) and engineered in parallel by fine-tuning enzyme expression, resulting in two engineered whole-cell catalyst modules, BL21(FM01) and BL21(SM13), capable of converting 30 mM 3,4-dihydroxybenzaldehyde to 28.7 mM hydroxytyrosol with a high space-time yield (0.88 g/L/h). To summarize, the current study proposes a simple and effective approach for biosynthesizing hydroxytyrosol from low-cost substrates and thus has great potential for industrial applications.

Synergistic protective effects of 3,4-dihydroxyphenylglycol and hydroxytyrosol in male rats against induced heat stress-induced reproduction damage.

Testicular heat stress disrupts spermiogenesis and damages testicular tissue. The study aims to assess 3,4-dihydroxyphenylglycol (DHPG) and hydroxytyrosol (HT) from olive oil as antioxidants to reduce heat-induced testicular damage. Seven groups of 35 male rats were used. Group I got normal saline. Group 2 had HS (43 °C for 20 min/day) and normal saline for 60 days. Groups 3-7 had HS and DHPG/HT doses (0.5 mg/kg DHPG, 1 mg/kg DHPG, 5 mg/kg HT, 0.5 mg/kg DHPG + 5 mg/kg HT, and 1 mg/kg DHPG + 5 mg/kg HT). The evaluation included tests on testicular tissue, sperm quality, oxidative status, gene activity, and fertility after 60 days. After DHPG and HT treatment, sperm motility, viability, and plasma membrane functionality, as well as levels of total antioxidant capacity (TAC), glutathione peroxidase (GPx), superoxide dismutase (SOD), and catalase (CAT), and Bcl-2 gene expression, and in vivo fertility indexes increased. Meanwhile, abnormal morphology and DNA damage decreased, along with levels of glutathione (GSH), nitric oxide (NO), and malondialdehyde (MDA), and Bax, caspase-3, and caspase-9 gene expression, compared to the HS group. The study found that DHPG and HT have a more substantial synergistic effect when used together, improving reproductive health.

Examination of internal metabolome and VOCs profile of brewery yeast and their mutants producing beer with improved aroma.

Volatile organic compounds (VOCs) are metabolites pivotal in determining the aroma of various products. A well-known VOC producer of industrial importance is Saccharomyces cerevisiae, partially responsible for flavor of beers and wines. We identified VOCs in beers produced by yeast strains characterized by improved aroma obtained in UV-induced mutagenesis. We observed significant increase in concentration of compounds in strains: 1214uv16 (2-phenylethyl acetate, 2- phenylethanol), 1214uv31 (2-ethyl henxan-1-ol), 1214uv33 (ethyl decanoate, caryophyllene). We observed decrease in production of 2-phenyethyl acetate in strain 1214uv33. Analysis of intracellular metabolites based on 1H NMR revealed that intracellular phenylalanine concentration was not changed in strains producing more phenylalanine related VOCs (1214uv16 and 1214uv33), so regulation of this pathway seems to be more sophisticated than is currently assumed. Metabolome analysis surprisingly showed the presence of 3-hydroxyisobutyrate, a product of valine degradation, which is considered to be absent in S. cerevisiae. Our results show that our knowledge of yeast metabolism including VOC production has gaps regarding synthesis pathways for individual metabolites and regulation mechanisms. Detailed analysis of 1214uv16 and 1214uv33 may enhance our knowledge of the regulatory mechanisms of VOC synthesis in yeast, and analysis of strain 1214uv31 may reveal the pathway of 2-ethyl henxan-1-ol biosynthesis.

[Advances in synthesis of 2-phenylethanol].

2-phenylethanol (2-PE), an aromatic alcohol with a rose fragrance, is the second most widely used flavoring substance in the world. It is widely used in the cosmetic, food, and pharmaceutical industries. This paper introduces the chemical synthesis methods of 2-PE and the synthetic pathways in plants and microorganisms, summarizes the strategies to improve the microbial synthesis of 2-PE, reviews the research progress in de novo synthesis of 2-PE in microorganisms, and makes an outlook on the research prospects, aiming to provide a theoretical basis for the industrial production of 2-PE.

Effects of hydroxytyrosol on post-thaw quality of rooster sperm.

Semen cryopreservation is one of the most important reproduction techniques in the livestock and poultry industry. Cryopreservation induces cold stress, generating reactive oxygen species (ROS) and oxidative stress causing structural and biochemical damages in sperm. In this study, we evaluated the effects of the hydroxytyrosol (HT), as an antioxidant, at the concentrations of 0, 25, 50, and 100 µg/mL on post-thaw semen quality metrics in rooster. Semen samples were collected twice a week from 10 roosters (29 weeks), processed and frozen according to experimental groups. Different quality parameters, including total motility, progressive motility, viability, morphology, membrane integrity, and malondialdehyde were measured after thawing. Results showed that 25 and 50 µg/mL of HT produced the highest percentage of total motility (51.01 ± 2.19 and 50.15 ± 2.19, respectively) and progressive motility (35.74 ± 1.34 and 35.15 ± 1.34, respectively), membrane integrity (48.00 ± 2.18 and 46.75 ± 2.18, respectively) as well as viability (53.00 ± 2.17 and 52.50 ± 2.17, respectively) compared with the other groups (p < .05). The group with 25 µg/mL of HT showed the lowest significant (p < .05) MDA concentration (1.81 ± 0.25). Our results showed that the effect of HT was not dose-dependent and optimum concentration of HT could improve functional parameters of rooster sperm after freezing-thawing. These findings suggest that HT may have protective effects on the rooster sperm during the freezing-thawing process.