Xanthohumol (XH) is an important prenylated flavonoid that is found within the inflorescence of
L. (Hop plant). XH is an important ingredient in beer and is considered a significant bioactive agent ...due to its diverse medicinal applications, which include anti-inflammatory, antimicrobial, antioxidant, immunomodulatory, antiviral, antifungal, antigenotoxic, antiangiogenic, and antimalarial effects as well as strong anticancer activity towards various types of cancer cells. XH acts as a wide ranging chemopreventive and anticancer agent, and its isomer, 8-prenylnaringenin, is a phytoestrogen with strong estrogenic activity. The present review focuses on the bioactivity of XH on various types of cancers and its pharmacokinetics. In this paper, we first highlight, in brief, the history and use of hops and then the chemistry and structure-activity relationship of XH. Lastly, we focus on its prominent effects and mechanisms of action on various cancers and its possible use in cancer prevention and treatment. Considering the limited number of available reviews on this subject, our goal is to provide a complete and detailed understanding of the anticancer effects of XH against different cancers.
•Spatialized data were used for a more accurate analysis of hopyard production traits.•A weak negative relation was found between clay content of the soil and hop yields in a Mediterranean ...environment.•Shoot production before training was positively and strongly related to cone yield of cultivar Cascade.•Cultivar Cascade proved to be well adapted to the Mediterranean environment.•Organic hop production is feasible under the Mediterranean climatic conditions.
The cultivated hops are recently moving towards new growing areas in Southern Europe, boosted by the increasing number of craft breweries and by the higher vulnerability to climate change observed, for this crop, in the traditional growing regions. Despite this clear market and geographic trend, there is a lack of knowledge about pedoclimatic needs and agronomic performances of hops grown in the Mediterranean environment. Particularly, the agronomic potential of a new hopyard during its establishment period is poorly studied even in traditional growing zones. Moreover, a restricted number of plants were usually sampled to gather the few data available, thus leading to a probable overestimation of yield performance. A commercial organic hopyard in central Italy was established and a 2-year (2018–2019) field experiment was set-up to accurately investigate the cone and shoot yield potential of cultivar ‘Cascade’ and to understand how such yields are related to each other and to soil texture. Hop plants were two-years old when the experiment started; plant population was 4,000 plants ha−1. Forty points within the hopyard were sampled for soil analysis and yield traits. Data were analyzed accounting for spatial dependence of the sampling points. Results show a negative relation between clay content in the soil and hop yields, even though it was significant only in the exceptional rainy season of 2018. Shoot and cone yield were positively and strongly related, suggesting the green shoot yield in spring as a good predictor of hop production. Both shoot and cone yield significantly increased from the second to the third year (+11% and +16%, respectively); however, the unseasonably high rainfall of 2018 probably lowered the yield of the first experimental year. Cone yield attained over this 2-year study (1.24 t ha−1 and 1.44 t ha−1 for 2018 and 2019, respectively) was within the published ranges for mature plants. Similarly to cone production, shoot dry matter yield was lower in 2018 (197 kg ha−1) than in 2019 (218 kg ha−1). This study provides the first reliable information on both cone and shoot yield potential of a young organic hopyard under Mediterranean climatic conditions.
Constantly increasing pressure to implement the principles of integrated production of hops results in the need for new plant protection products. Various plant extracts, also called botanicals, have ...potential to be used as alternatives to conventional pesticides. In three-year field trials on virus-free seedlings of Saaz hops, the efficacy of thyme essential oil, hops extract and algae extract against hops downy mildew (Pseudoperonospora humuli) was investigated. Different concentrations (0.5–1%) of plant extracts were applied to the hop plants six times during vegetative growth, and the degree of damage caused by P. humuli, the health condition and the chlorophyll content in the hops were evaluated after selected applications. All botanicals demonstrated very good antifungal properties comparable to treatment with commercial fungicides. Even one dose of plant extract was able to significantly suppress disease development for two months compared to untreated control. Thyme oil (0.5%) was considered to be the most effective botanical. Not only did it have good antifungal properties, but it also had positive influence on the chlorophyll content (up to 30% increase). These trials have shown that all botanicals tested have the potential to be used in an integrated, ecological hop production system.
•Plant extracts were able to significantly suppress development of hops downy mildew.•Plant extracts had positive influence on the chlorophyll content in hop leaves.•Thyme oil (0.5%) was the most effective botanical.
Hop (Humulus lupulus L.) is an essential ingredient of beer, where it provides the typical bitter taste, but is also applied in traditional folk medicine for sedative and antibacterial purposes. In ...this study, we demonstrate and compare the anti-inflammatory effect of various classes of hop bitter acids (HBA), including -acids (AA), -acids (BA), and iso-acids (IAA), in fibroblasts, which are important players in the inflammatory response. All three studied classes of HBA blocked the tumor necrosis factor alpha (TNF)-induced production of the cytokine IL6, and inhibited the transactivation of the pro-inflammatory transcription factors nuclear factor kappa B (NF-B), activator protein-1 (AP-1), and cAMP-response element-binding protein (CREB). In this respect, the six-membered ring compounds AA and BA showed equal potency, whereas the five-membered ring compounds, IAA, were effective only when used at higher concentrations. Furthermore, with regard to the mechanism of NF-B suppression, we excluded a possible role for glucocorticoid receptor alpha (GR), peroxisome proliferators-activated receptor alpha/gamma (PPAR or PPAR), nuclear receptors (NRs) that are also known to inhibit inflammation by directly interfering with the activity of pro-inflammatory transcription factors. Interestingly, combining hop acids and selective agonists for GR, PPAR, or PPAR resulted in additive inhibition of NF-B activity after TNF treatment, which may open up new avenues for combinatorial anti-inflammatory strategies with fewer side effects. Finally, systemic administration of HBA efficiently inhibited acute local inflammation in vivo.
The hydrogenionic potential (pH) is one of the parameters that characterize the quality of water for irrigation, and can influence soil microbiology and the cation exchange process between soil and ...plant. However, there are few studies related to the pH of irrigation water for hop culture. According to this, our work aimed to evaluate the irrigation effect with different water pH ranges on the agronomic development of hops grown in a greenhouse, in Botucatu, state of São Paulo, Brazil. It was used a completely randomized design (CRD), with three treatments (pH levels) and ten replications. The treatments consisted of three water pH levels: T1 – 6 to 6.5, T2 – 6.5 to 7, and T3 – 7 to 7.5. To obtain the different pH ranges were used solutions of 0,1 mol L−1 of sodium hydroxide (NaOH), and phosphoric acid (H3PO4). Gas exchanges, nutritional content in plant leaf tissue, yield, and alpha and beta-acids concentration were evaluated. The results obtained allowed us to conclude that the pH range 6.5 to 7 promotes greater availability, absorption, and accumulation of K in plant leaf tissue, as well as greater photosynthetic capacity, in addition to greater yield between treatments. The preliminary values of alpha and beta-acids were higher in plants irrigated with the water pH of T1, indicating that possible stress may favor the production of these compounds.
•The agronomic development of hops (v. Cascade) is influenced by the different pH ranges of the irrigation water.•The range of 6.5 to 7 promotes greater availability and absorption of K+ ions, photosynthetic capacity, and cone yield.•The pH range 7 to 7.5 becomes harmful to the hop culture.•Stress can favor the production of alpha and beta-acids.
The twospotted spider mite (Tetranychus urticae Koch) is a common pest in agricultural and ornamental crops. This pest can be controlled by resident predatory arthropods in certain situations. This ...research quantified the stability and resiliency of established conservation biological control of the twospotted spider mite in hop over a 5-yr period associated with nitrogen fertilization rate and use of a broad-spectrum insecticide. Biological control generally was stable and resilient over a sixfold range of nitrogen fertilization rates, and in only 1 of 5 yr did elevated nitrogen rates significantly affect populations of spider mites. In contrast, one application of the insecticide bifenthrin was associated with disruption of biological control and a severe outbreak of spider mites. The complex of natural enemies suppressed the outbreak during the same year in which bifenthrin was applied, but only after populations of spider mites exceeded levels associated with economic damage. However, in the following year the system returned to an equilibrium state where spider mites were suppressed below economically damaging levels. Therefore, conservation biological control in hop appears stable and robust to factors such as nitrogen fertilization that increase reproductive rates of spider mites but may be sensitive to factors such as nonselective insecticides that are lethal to natural enemies. Conservation biological control can be considered resilient to a single use of a nonselective insecticide in the year following the application, but not within the year of application.
Xanthohumol (XN) and demethylxanthohumol (DMX) are specialized prenylated chalconoids with multiple pharmaceutical applications that accumulate to high levels in the glandular trichomes of hops ...(Humulus lupulus L.). Although all structural enzymes in the XN pathway have been functionally identified, biochemical mechanisms underlying highly efficient production of XN have not been fully resolved. In this study, we characterized two noncatalytic chalcone isomerase (CHI)-like proteins (designated as HlCHIL1 and HlCHIL2) using engineered yeast harboring all genes required for DMX production. HlCHIL2 increased DMX production by 2.3-fold, whereas HlCHIL1 significantly decreased DMX production by 30%. We show that CHIL2 is part of an active DMX biosynthetic metabolon in hop glandular trichomes that encompasses a chalcone synthase (CHS) and a membrane-bound prenyltransferase, and that type IV CHI-fold proteins of representative land plants contain conserved function to bind with CHS and enhance its activity. Binding assays and structural docking uncover a function of HlCHIL1 to bind DMX and naringenin chalcone to stabilize the ring-open configuration of these chalconoids. This study reveals the role of two HlCHILs in DMX biosynthesis in hops, and provides insight into their evolutionary development from the ancestral fatty acid-binding CHI-fold proteins to specialized auxiliary proteins supporting flavonoid biosynthesis in plants.
•Leaves of the hop plant (Humulus lupulus L.) are an agricultural by-product.•Two hop cultivars from four different hop-growing regions in Europe were studied.•The leaves had 3-fold to 30-fold less ...total phenolics than the cones.•The leaves had much lower DPPH radical scavenging activity than the cones’ extracts.•All hop cones extracts had extraordinary antimicrobial activity against gram positive Staphylococcus aureus.
The leaves of the hop plant (Humulus lupulus L.) are an agricultural by-product that is not currently being exploited. This study compared two hop cultivars cv. ‘Aurora’ and cv. ‘Hallertauer Magnum’ from four different hop-growing regions (Žalec, Slovenia; Leutschach (Kranach), Austria; Hüll, Germany; Žatec, Czech Republic). The leaves and cones were collected and their total phenolics and the antioxidative and antimicrobial activities of their ethanol extracts were determined. Samples were collected three years in succession (2008–2010). Total phenolics ranged from 0.099 to 0.542mgCAE/mL for the leaf extract and from 0.738 to 1.734mgCAE/mL for the cones, which had both higher levels and greater variability of phenolics. The leaves had much lower DPPH radical scavenging activity. Their IC50 of approximately 0.020mg/mL was much higher than the cones’ extracts (0.005 to 0.010mg/mL) regardless of the year and of the growing location. The best reducer was the extract from the Aurora leaves collected in the Czech Republic in 2010, which reduced 0.117mL/μg of ferric ions in 25min. Antimicrobial activity against gram positive Staphylococcus aureus was extraordinary for all hop cones extracts (minimal inhibitory concentrations, MICs<0.003mg/mL), while moderate antimicrobial activity (MICs>0.16mg/mL) against gram negative Escherichia coli O157:H7 was observed for hop cones and leaves extracts. The results of the profile analysis showed the caffeic acid peak at tr=35.1min for the leaves, while the cones had no such peak at that retention time.
We report the identification of two single nucleotide polymorphisms in Cannabis sativa L. that are associated with female and male plant sex phenotypes and are located on the top arm of the X ...chromosome. High resolution melt analysis was used to develop and validate a novel, rapid method for sex identification in medical and (or) recreational cannabis as well as in hemp. This method can distinguish between dioecious male (XY) and dioecious female (XX) cannabis plants with 100% accuracy and can also be used to differentiate between male and female Humulus lupulus L. (hop) plants.
Tomahawk hop (Humulus lupulus) is a recently developed Super Alpha cultivar (14-18% alpha-acids w/w), already widely used by brewers to impart bitterness and a citrus-like aroma to beer. By ...comparison with two bitter varieties (Nelson Sauvin and Nugget) and two aromatic ones (Cascade and Saaz), the Tomahawk cultivar showed a very particular terpenoid profile, rich in both alpha- and beta-selinenes (>600 mg/kg IST equiv in total), methyl geranate (>40 mg/kg IST equiv), and geraniol (>200 mg/kg). Tomahawk also proved to contain a wide variety of odorant polyfunctional thiols. The major beta-sulfanyl acetate, 3-sulfanyl-2-ethylpropyl acetate, newly identified here, was found at similar levels in the famous Sauvignon-like Nelson Sauvin and Tomahawk varieties (15-44 micrograms/kg IST equiv). On the other hand, lower levels of total beta-sulfanyl alcohols were measured in Tomahawk, although 3-sulfanylhexan-1-ol was found at a similar level and the 3-sulfanyl-4-methylpentan-1-ol previously claimed to be specific to the Nelson Sauvin variety was also evidenced in the Super Alpha cultivar (9-13 micrograms/kg IST equiv). As revealed by boiling and fermentation, Tomahawk hop also contains very interesting bound polyfunctional thiols that should be investigated for better use by brewers.
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