Search Results (236)

Green and white hop shoots are routinely removed during hop production and represent an underutilized biomass stream with potential for valorization. This study evaluated the biomass yield and polyphenolic composition of shoots from three cultivated hop varieties, Aurora, Celeia, and Styrian Wolf. White and green shoots were sampled in 2021, while green shoots were additionally sampled in 2023. Total phenolics were determined by the Folin–Ciocalteu method, and individual polyphenols were quantified by HPLC. Green-shoot biomass removed during training differed significantly among varieties, ranging from 76 kg/ha in Aurora to 188 kg/ha in Styrian Wolf. Total phenolic content of green shoots ranged from 2.22 to 3.47 mg CAE/g dry matter, with Styrian Wolf showing the highest value. Polyphenolic profiles differed markedly between shoot types: white shoots contained higher concentrations of catechin, epicatechin, and naringin, whereas green shoots contained quercetin, higher ferulic acid levels, and the hop-specific prenylflavonoid xanthohumol. Interannual variation was compound-specific at green shoots: the wetter February–April period in 2021 coincided with higher epicatechin and ferulic acid concentrations, whereas naringin and 4-hydroxybenzoic acid were higher in the drier 2023 February–April period. Compared with commonly consumed polyphenol-rich foods, hop shoots contained relatively low concentrations of individual polyphenols; however, their routine generation as an agricultural side stream may make them an attractive raw material for selective recovery of specific compounds, particularly hop-specific xanthohumol. Full article

Xanthohumol (XN), a prenylated chalcone isolated from Humulus lupulus L., exhibits a wide range of biological activities, including antioxidant, anti-inflammatory, and chemopreventive effects. However, its therapeutic application is limited by poor aqueous solubility, low chemical stability, and rapid clearance from the systemic circulation. The present study aimed to develop and characterize a novel nano-sized drug-delivery system for XN that combines favourable colloidal stability, efficient encapsulation, sustained release, and reduced recognition by macrophages (“stealth-like” properties). To achieve this, XN-loaded cationic liposomes were coated with two marine polysaccharides, iota-carrageenan (CAR) and fucoidan (FUC), followed by Ca²⁺-mediated cross-linking. Liposomes were prepared by the ethanol injection method, and formulation parameters were optimized using a 2³ + 1 full factorial design. Surface modification and cross-linking conditions were further optimized through polyelectrolyte titration and a Taguchi L9 orthogonal array. The resulting nanocarriers were evaluated for particle size, polydispersity, ζ-potential, encapsulation efficiency, release behavior, and cellular uptake. Both coatings significantly prolonged XN release compared with uncoated liposomes, with CAR-coated vesicles providing the most sustained release (≈55% over 48 h). In RAW264.7 macrophages, 50 µg/mL CAR-coated liposomes reduced cellular uptake by approximately 74% following 1-h incubation relative to uncoated controls and maintained this reduction over 2 h whereas FUC-coated vesicles afforded only transient early evasion. The cross-linked iota-carrageenan coating thus represents a promising strategy for conferring stable “stealth-like” characteristics to XN-loaded liposomes intended for prolonged drug delivery. Full article

Antioxidant activity of plant extracts is commonly interpreted as a directly comparable property despite substantial methodological differences among analytical assays and extraction systems. This study investigated how extraction selectivity and assay chemistry influence antioxidant-associated responses in hop (Humulus lupulus L.) extracts by integrating experimental and literature-derived datasets. Extracts obtained using different solvents and extraction techniques were evaluated using ABTS, DPPH, and Folin–Ciocalteu (TPC) systems. Multivariate statistical analyses, including principal component analysis (PCA), correlation analysis, and non-parametric comparisons, were applied to normalized datasets to assess assay-dependent variability and cross-study comparability. The results suggested substantial divergence between ABTS- and DPPH-associated responses, including a statistically significant negative correlation between both assay systems. PCA indicated assay-selective separation patterns, while TPC values did not consistently correlate with antioxidant-associated responses. Different extraction conditions were associated with distinct antioxidant response profiles, suggesting selective redistribution of analytically detectable antioxidant fractions rather than uniform changes in antioxidant capacity. Based on these observations, this study proposes the Assay–Extraction Interaction Framework (AEIF), an interpretative framework that views antioxidant activity as a context-dependent analytical response rather than a universal intrinsic property of the extract. Full article

Hops (Humulus lupulus L.) are a phytochemical resource rich in bitter acids, prenylated flavonoids, and essential oils with antimicrobial, antifungal, antioxidant, and anti-inflammatory activities relevant to animal production. This review critically synthesizes the phytochemical profile of H. lupulus and the available in vivo evidence on its use as a functional feed additive in poultry, freshwater aquaculture, swine, and ruminants, identifying research gaps and regulatory barriers. In poultry, microencapsulated β-acids at 30 mg/kg feed achieved a feed conversion ratio comparable to zinc bacitracin, while lupulone reduced intestinal Clostridium perfringens counts by >4 log units, from log₁₀ 6.20 to 2.00 CFU/g; doses ≥240 mg/kg induced adverse effects. In freshwater aquaculture, hop extract at 750 mg/kg feed improved hepatic markers and fillet fatty acid composition in common carp, whereas isolated hop acids at 308 mg/kg increased final body weight in Nile tilapia (157.3 vs. 150.3 g) without sensory rejection even at 1230 mg/kg. In swine, granulated cones improved feed conversion (3.5 vs. 4.3 kg/kg), while purified β-acids up to 360 mg/kg improved performance comparably to colistin. In ruminants, hop residues, pellets, and cones were tolerated without consistent production benefits. Overall, hop-derived additives show dose-, compound-, and matrix-dependent effects, requiring standardized formulations, species-specific pharmacokinetics, pathogen-challenge validation, long-term safety assessment, and regulatory dossiers. Full article

Verticillium wilt of hop (Humulus lupulus L.), caused by the soil-borne pathogen Verticillium nonalfalfae, is a devastating disease with no effective chemical control. In European hop-growing regions, breeding resistant cultivars is the most effective strategy. The lack of response differences in earlier studies suggests constitutive resistance. We therefore conducted a genome-wide association study (GWAS) using a phased hop genome assembly to improve detection of Verticillium resistance loci. A bi-parental population of 142 genotypes, derived from a cross between resistant Wye Target and susceptible BL2/1, was phenotyped for Verticillium wilt resistance and genotyped by sequencing. Association analyses with five statistical models (MLM in TASSEL 5, MLM, MLMM, FarmCPU and BLINK in GAPIT) did not identify any significant SNPs; however, several candidate loci were identified using exploratory threshold, particularly in the phase 2 genome assembly, including a wall-associated kinase (WAK) consistently detected across both genome phases and all models. GWAS results were further assessed with a Random Forest model, which identified SNPs of high feature importance and showed adequate predictive power (accuracy ≈ 0.4, correlation ≈ 0.8) for preliminary breeding screening. These findings provide an initial set of candidate markers and exploratory prediction models for Verticillium wilt resistance in hop, representing a valuable genomic resource for future marker-assisted selection and breeding strategies. Full article

The present study aimed to characterize the vegetative growth and phenology of hop cultivars grown in successive seasons with artificial supplementation in a subtropical region. The experiment was conducted in Palotina, Paraná, Brazil (24° S) during the summer 2023–2024, winter 2024, and fall 2024–2025 growing seasons. LED lamps were used to extend the daily photoperiod to 17 h during the vegetative phase. The following hop cultivars were assessed: (a) Alpharoma; (b) Cascade; (c) Chinook; (d) Comet; (e) Dr. Rudi; (f) Hallertau Magnum; (g) Hallertau Mittelfruher; (h) Nugget; (i) Saaz; (j) Smooth; (k) Sorachi Ace; (l) Southern Cross; (m) Triple Pearl; (n) Yakima Gold; (o) Zeus. The assessed variables included plant height (Ht), hop growth rate (HGR), classification of four growth stages, number of lateral shoots, plant fresh mass, and phenology. Ht and HGR were analyzed by means of Gompertz and Gaussian regression models, respectively. The number of lateral shoots per plant and fresh mass were subjected to analysis of variance (ANOVA), and means were grouped using the Scott-Knott test (p < 0.01). Seasonal temperature fluctuations, associated with advancing age and plant establishment throughout successive cycles, acted as important modulating factors in vegetative growth and phenology. In the summer season (2023–2024), Cascade and Hallertau Magnum were characterized as early cultivars. In the winter season (2024), Chinook, Nugget, Saaz, and Zeus were classified as early cultivars, while in the fall season (2024–2025), Dr. Rudi, Sorachi Ace, and Zeus were also considered early hops. The vegetative growth Stage I was found to be critical for earliness classification. The phenological cycle variability was amplified during seasons with higher temperatures. The ‘Sorachi Ace’, ‘Triple Pearl’, and ‘Zeus’ hops were the only ones capable of completing the phenological cycle in all three harvest seasons, with ‘Sorachi Ace’ standing out due to its uniform, stable growth pattern regardless of the season. It is concluded that successive hop cultivation is technically viable for specific hop cultivars grown under subtropical conditions with supplemental lighting. Full article

Hops (Humulus lupulus L.) is a plant species with a multitude of uses in medicine, food science and agriculture. Xanthohumol, the major prenylflavonoid in hop cone extract, possesses anti-cancer activity. Xanthohumol also exhibits strong antimicrobial activity against Gram-positive bacteria (e.g., S. aureus), but not against Gram-negative bacteria. Xanthohumol can reduce blood glucose levels and body fat in obese male rats (not females), and mature hop bitter acids (MHBAs) have been found to decrease visceral and abdominal human fat. Xanthohumol can increase bone mineral density, decrease osteoclast numbers, and protect osteoblasts from oxidative stress in osteoporotic mice. Further clinical research, xanthohumol and bitter acids could be sourced from hop cone extracts to formulate novel drugs that can successfully treat a variety of diseases and potentially replace current therapies that have negative effects. In the food industry, hop cone extracts are mainly used in the brewing industry, with 98% of the world’s hop cones being used in brewing beer. Hop cone extracts are also used as food/drink preservatives due to their antimicrobial abilities, as previously mentioned, although there is less of a need for hops in extending food/drink shelf-life. Finally, hop cone extracts have several uses in agriculture, mainly as pesticides. For example, hop extracts can kill varroa mites, a parasite that impairs honeybee health. This benefits honeybee farmers as increased bee survival means more honey production, increasing profits. Overall, this review paper brings together recent studies that highlight hop extracts as valuable bioactive compound mixtures with many useful applications. Full article

The immature stages and biology of Neoplinthus tigratus porculus (Fabricius, 1801) (Coleoptera: Curculionidae: Molytinae) associated with common hop (Humulus lupulus L.) are described for the first time. Biological observations show that the species develops mainly within the root collar and roots of Humulus lupulus, where larvae feed internally and older instars overwinter. Infested plants are characterized by swollen and weakened roots, often containing multiple larvae. The species should be considered a potential pest of common hop, an economically important crop; however, the current observations indicate that its populations are generally very low, consistent with the status of several related Molytinae and Cleonini taxa, which are predominantly regarded as rare or locally occurring under contemporary agricultural conditions. Nevertheless, changes in agroecosystem management may significantly alter its abundance, as documented in other weevil taxa, where reductions in plant protection measures have led to local pest outbreak. The morphology and diagnostic characters of mature larvae and pupae are documented and compared with related Molytinae and selected Cleonini (Lixinae). The mature larva generally fits the diagnostic characters of Molytinae larvae but differs in several traits, particularly the very short endocranial line and the relative length of frontal setae (fs_1–5), with fs₄ distinctly shorter than fs₅. Full article

Isoxanthohumol (IX) is a prenylated flavonoid derived from hop cones (Humulus lupulus) that is gaining increasing recognition for its potential biological effects. Despite numerous studies on its precursor, xanthohumol, studies on IX remain limited. Of particular interest is its metabolism, particularly its biotransformation by gut microbiota to 8-prenylnaringenin (8-PN), a potent phytoestrogen, which indicates the complex nature of its biological activity and potential health implications. This review summarizes the current state of knowledge on IX and its derivatives, covering their microbial metabolism, their impact on the gut microbiome, and the metabolic consequences of this conversion. Furthermore, it examines the relationship between the molecular structure of IX and its derivatives and their biological activity, highlighting existing research gaps and the need for further research on the safety and therapeutic potential of these compounds Full article

Hop (Humulus lupulus L.) cones are increasingly recognized as sources of phenolic compounds relevant to antioxidant-oriented applications beyond their traditional brewing role; however, genotype-dependent chemical diversity remains poorly characterized under South American cultivation. This study evaluated phenolic composition and antioxidant-related chemical signatures in 22 hop accessions, including commercial varieties and Chilean local ecotypes, cultivated under homogeneous conditions in southern Chile. Total phenolic content (TPC), total flavonoid content (TFC), and condensed tannins were determined using spectrophotometric assays, while phenolic acids, catechin, and prenylated flavonoids were quantified by HPLC. Antioxidant capacity was evaluated using the ORAC assay, and principal component analysis (PCA) was applied to integrate chemical variables. TPC ranged from 4051 to 8124 mg gallic acid equivalents/100 g dry weight, TFC from 655 to 3011 mg quercetin equivalents/100 g, and condensed tannins from 11.0 to 60.1 mg catechin equivalents/g. ORAC values ranged from 96,405 to 161,815 µmol Trolox equivalents/100 g dry weight, indicating substantial genotype-dependent variation. PCA explained 69.5% of total variance and revealed distinct phenolic composition patterns among genotypes. Pearson correlation analysis showed that antioxidant capacity was strongly associated with condensed tannins and total phenolic content, whereas total flavonoids were not significantly related to ORAC values. Prenylated flavonoids were negatively associated with antioxidant capacity, suggesting a limited contribution to peroxyl radical scavenging activity. These findings highlight the importance of phenolic subclass composition, particularly condensed tannins, in determining antioxidant capacity and support the selection of hop genotypes based on specific phenolic profiles for functional applications. Full article

This study investigates the antioxidant, enzyme inhibitory, and antimicrobial activities of water (WEHL) and ethanol (EEHL) extracts of hop (Humulus lupulus) cones. Phytochemical analyses revealed higher total phenolic content in EEHL (271.52 ± 0.13 mg GAE/g) than in WEHL (251.84 ± 0.06 mg GAE/g), as well as higher total flavonoid content (182.56 ± 0.45 mg QE/g for EEHL versus 179.39 ± 0.46 mg QE/g for WEHL). Antioxidant activity, determined by DPPH and ABTS assays, showed that EEHL had stronger radical scavenging capacity with IC₅₀ values of 19.13 ± 4.66 μg/mL (DPPH) and 12.66 ± 1.94 μg/mL (ABTS), compared to WEHL (DPPH: 20.90 ± 2.39 μg/mL; ABTS: 32.41 ± 4.29 μg/mL). In reducing assays, EEHL also showed better absorbance values in FRAP (0.77 ± 0.01), CUPRAC (2.09 ± 0.05), and Fe³⁺ reducing (1.95 ± 0.01) tests. EEHL likely outperformed WEHL due to solvent polarity and extraction efficiency. Moderately polar ethanol extracts a broader range of phenolics and flavonoids, including fewer polar bioactive compounds that contribute to antioxidant capacity and enzyme inhibition. This matches higher TPC/TFC in EEHL and explains stronger radical scavenging, reducing power, and multi-enzyme inhibition. Enzyme inhibition studies revealed that EEHL inhibited acetylcholinesterase (IC₅₀: 26.06 μg/mL), butyrylcholinesterase (IC₅₀: 44.00 μg/mL), α-glycosidase (IC₅₀: 119.31 μg/mL), and carbonic anhydrase isoenzymes hCA I (IC₅₀: 59.78 μg/mL) and hCA II (IC₅₀: 21.19 μg/mL). LC–MS/MS analysis identified major phenolic compounds such as isoquercitrin (3.14 ng/mL), rutin (0.60 ng/mL), and hesperidin (0.43 ng/mL) in EEHL. Antimicrobial screening showed selective activity against Staphylococcus aureus with an inhibition zone of 18.50 ± 0.58 mm, while no inhibition was observed against Escherichia coli and Candida albicans. These findings provide a solvent-dependent in vitro profile that can guide extraction strategies, support antioxidant and multi-enzyme screening (including hCA I and II), and identify candidates for selective antimicrobial evaluation and further preclinical investigation. Despite extensive use of hop extracts, comparative solvent-dependent profiling that links LC–MS/MS phenolic composition with a broad multi-enzyme inhibition panel, including the less frequently evaluated hCA I/II isoenzymes, remains limited. Therefore, the objective of this study was to systematically compare WEHL and EEHL in terms of phytochemical content and in vitro antioxidant, enzyme inhibitory, and antimicrobial activities. Overall, these results provide a solvent-dependent, comparative in vitro profile of WEHL vs. EEHL that can support antioxidant, multi-enzyme screening (including hCA I and II), and selective antimicrobial assays. Full article

Introduction/Objective: Common hop (Humulus lupulus L.) is a multi-component plant material that has been extensively studied for its antioxidant, anti-inflammatory, cardioprotective, metabolic, neuroprotective, immunomodulatory and anti-cancer properties. This review summarises current data on the molecular mechanisms of action of hop compounds, their therapeutic potential, metabolic interactions and biological significance, with particular emphasis on bioavailability, signalling pathways and organ-specific effects. Methods: A comprehensive literature review was conducted, covering in vitro and in vivo studies and available clinical trials analysing the biochemical activity, molecular targets and physiological effects of bioactive compounds in hops. Particular attention was paid to the regulation of oxidative stress, inflammatory signalling, mitochondrial function, metabolic pathways, interactions with the gut microbiota and their impact on the development of chronic diseases. Results: Bioactive compounds in hops modulate numerous key signalling pathways, including NF-κB, Nrf2, AMPK, MAPK, PPAR and PI3K/AKT/mTOR. They have been shown to reduce oxidative stress, inhibit the production of pro-inflammatory cytokines, regulate apoptosis, improve mitochondrial function, and activate endogenous antioxidant systems. Hops have a protective effect in cardiovascular diseases, metabolic disorders, neurodegenerative diseases and selected cancers through anti-inflammatory, anti-proliferative and metabolic mechanisms. In addition, hop compounds modulate the composition and activity of the gut microbiota, which promotes improved metabolic homeostasis. Despite relatively good intestinal absorption, systemic bioavailability remains limited; however, modern delivery systems significantly increase the stability and plasma concentrations of these compounds. Conclusions: Common hops have broad therapeutic potential due to their ability to regulate oxidative, inflammatory, metabolic and apoptotic processes at multiple levels. Their pleiotropic activity makes them a promising candidate for the prevention and treatment of chronic diseases. The development of delivery systems and consideration of the role of the gut microbiota may further increase its clinical application. Full article

Mastitis in dairy cows, caused by pathogens such as Staphylococcus aureus, Escherichia coli, and Candida albicans, leads to substantial economic losses and contributes to antimicrobial resistance, emphasizing the need for natural alternatives. This study assessed the phytochemical composition, antioxidant activity, and in vitro antimicrobial effects of ethanol extracts from ten medicinal plants, including Populus balsamifera buds, Syzygium aromaticum, and Humulus lupulus, as well as two multi-component plant mixtures and commercial products against reference strains and field isolates of mastitis pathogens. Extracts exhibited total phenolic contents ranging from 2.5 to 43.0 mg GE/g, with Populus balsamifera and Syzygium aromaticum demonstrating the strongest DPPH radical scavenging activity (IC₅₀ 1.89–2.9 mg/g extract). Disc diffusion assays demonstrated broad-spectrum inhibition, particularly for Populus balsamifera (15.1–19.1 mm inhibition zones) and Humulus lupulus (9.0–18.4 mm) against key pathogens; phenolic and flavonoid contents positively correlated with antimicrobial activity (r = 0.63–0.99, p < 0.001). Multi-component mixtures provided consistent broad-spectrum effects (12.6–17.2 mm). These phenolic-rich plant extracts represent promising alternatives to reduce antibiotic use in dairy mastitis management. Full article

Humulus lupulus L. (hops), belonging to the Cannabaceae family, is grown mainly for brewing, with 98% of global production directed to this sector. Moreover, large volumes of female cone residues are generated as by-products, representing a valuable source of bioactive compounds that can be valorized under green chemistry principles. This study aimed to extract bioactive compounds from hop cone residues sourced from craft breweries using ultrasound-assisted (EH-UA) and microwave-assisted (EH-MA) extraction methods. Hydroalcoholic extracts (70%) were analyzed for chemical composition, antioxidant, antimicrobial, antiproliferative, nitric oxide (NO)-production inhibition, and photoprotective activities. GC-MS identified 32 compounds in EH-MA and 30 in EH-UA, including terpenes, sesquiterpenes, oxygenated sesquiterpenes, and fatty acids. Both extracts demonstrated strong antioxidant activity in cell-based (TBARS, OxHLIA) and chemical (DPPH, ABTS, FRAP) assays, particularly EH-MA. Significant antibacterial activity was observed, especially against Enterobacter cloacae, Pseudomonas aeruginosa, and Staphylococcus aureus (MIC 1–10 mg/mL), as well as antifungal activity against Aspergillus brasiliensis (MIC 2–2.5 mg/mL). Selective antiproliferative activity was observed against tumor cell lines Caco-2 and MCF-7 (GI₅₀ 25 μg/mL), without cytotoxicity toward nontumor cell lines Vero and PLP2 (GI₅₀ > 400 μg/mL). All extracts inhibited the production of the inflammation mediator NO, with EH-MA showing the most potent effect (IC₅₀ of 35 μg/mL), followed by EH-UA (IC₅₀ of 55 μg/mL). Photoprotective potential was also demonstrated, with SPF values of 19 (EH-MA) and 18 (EH-UA). In conclusion, hop cone residues can yield multifunctional extracts with antioxidant, antimicrobial, antiproliferative, anti-inflammatory, and photoprotective activities, which support their sustainable upcycling for pharmacological, nutraceutical, and cosmetic applications. Full article

This study explores how extreme heat, farm design, and genotype interact to shape the growth, yield, and quality of hops (Humulus lupulus L.) in semi-arid Mediterranean environments, supporting climate-resilient expansion of high-value specialty crops beyond traditional production regions. Field performance of Cascade and Chinook was evaluated across contrasting management settings in inland Sicily during the 2023 growing season. Microclimatic observations from the Sicilian Agrometeorological Information Service (SIAS) were coupled with the quantitative heat-stress indicator Extra Degree Days (EDD) to link thermal exposure to phenology and quality outcomes. Results suggest that hop performance under semi-arid Mediterranean conditions is shaped by cultivar choice and management-defined environments, with cone yield and, especially, resin and essential oil traits varying across trellis and soil cover settings. Using phase-specific heat exposure as an interpretable indicator of thermal pressure, this study provides a decision-oriented framework to relate heat conditions to phenology and quality outcomes and to support the selection of cultivar–management combinations suited to heat-prone regions. Overall, the findings inform climate-smart hop management strategies to sustain cone quality amid increasing temperature variability in semi-arid environments. Full article