Identification of colupulone and lupulone as the main contributors to the antibacterial activity of hop extracts using activity-guided fractionation and metabolome analysis

Hops bitter β-acids have antibacterial effects against sinonasal Staphylococcus aureus but also induce sinonasal cilia and mitochondrial dysfunction

BACKGROUND

Routine prescription of antibiotics to treat chronic rhinosinusitis (CRS) exacerbations may contribute to the propagation of antibiotic resistance. Hops bitter β-acids lupulone and colupulone possess potent antibacterial activities and, as T2R1, T2R14, and/or T2R40 agonists, may improve the impaired mucociliary clearance described in CRS patients. We investigated these molecules as alternative treatments to antibiotics in CRS management based on their antibacterial and T2Rs agonists properties.

METHODS

Human nasal primary cells (HNECs) and RPMI2650 cells cultures were used as study models. T2Rs expression in cell culture models and human nasal tissue was assessed using immunofluorescence, quantitative PCR, and Western blot. We performed calcium imaging and cilia beat frequency experiments to investigate T2Rs activation in study models in response to lupulone and colupulone stimulations. Finally, we studied hops β-acids cytotoxicity on cells using CellEvent, crystal violet, lactate dehydrogenase assays, immunofluorescence, and transepithelial electrical resistance assays.

RESULTS

We confirmed lupulone and colupulone potent antibacterial effect on CRS-relevant methicillin-resistant Staphylococcus aureus but found minimal impact on P. aeruginosa. We also report T2R1, T2R14 and T2R40 expression in HNECs and RPMI2650 cell cultures. Lupulone and colupulone induced an increase in cytosolic calcium that appeared dependent on T2Rs signaling. This response was accompanied by mitochondrial membrane depolarization, cellular energy stress, decreased cell proliferation, ciliostasis, and HNECs remodeling after a single exposure to lupulone at micromolar concentrations.

CONCLUSION

Our data suggest that hops β-acids may not be beneficial as treatments in CRS patients and instead contribute to the disease by impairing cell health and further deteriorating the MCC.

Evaluation of Bacillus sp. strain isolated from pesticide influenced rhizospheric soil for dimethoate degrading potential

Pesticides play a major role in the current scenario of Indian agriculture. Agriculture is a backbone of the country's economy contributing to 54% of employment. Being a vastly populated country, food aid dependency rate is very high. To meet the requirements of such a huge supply, high crop yields are necessary to sustain the food security. Thus, an abundance use of pesticides is quite common, ranking among the top producers of pesticide in the world. Organophosphates (OPP) being one of the major pesticides used in India. Known for causing acute toxicity, organophosphate pesticides are needed to be used controllably, and residues released into the environment should be treated to render them harmless. Biological degradation is one of the most effective ways to achieve that. However, exploring potential candidate for the purpose is still not sufficient compared to the necessity to alleviate organophosphates from the environment. This study examines the microbial degradation of dimethoate, an organophosphate pesticide, using Bacillus paramycoides. These bacteria were isolated from the rhizospheric soil of sugarcane fields in Sevur, Tamil Nadu, India, which has been exposed to dimethoate for over 10 years. The strain has been extensively studied to check its prospect for environmental stress, pesticide tolerance, and degradation efficiency. Degradation of dimethoate was detected by Fourier transform infra-red spectroscopy (FTIR) analysis. The isolate was found to degrade dimethoate by 97.6% in 5 days with a tolerance of 1000ppm for the targeted pesticide. Emphasis have also been placed on detecting the secondary metabolites produced by the isolate using gas chromatography-Mass spectrometry(GC-MS) analysis, in which, a compound Phosphorothioic O, O,S-acid, a probable by-product of dimethoate degradation was identified. Significant other biologically important metabolites obtained from B.paramycoides, have also been reported in this study, which are known to have different anticancerous and antibacterial properties.

Antimicrobial activities of natural flavonoids against foodborne pathogens and their application in food industry

The application of natural alternatives as food preservatives has gained much attention due to the escalating negative perception of synthetic preservatives among consumers and the spread of drug-resistance foodborne pathogens. Natural flavonoids have the potential to be employed for food safety due to their antimicrobial properties against a wide range of foodborne pathogenic microorganisms. In this perspective, we reviewed the antimicrobial activities of natural flavonoids, the mechanism of action, as well as their application for food safety and quality. Various strategies for the incorporation of flavonoids into food products were highlighted, including direct addition to food formulations, encapsulation as micro or nanocarriers, and incorporation into edible or active films and coatings. Furthermore, we discussed the current challenges of industrial application of flavonoids, and proposed future trends to enhance their potential as natural preservatives. This review provides a theoretical foundation for the further development and application of flavonoids for food safety.

Antioxidant Activity of Humulus lupulus Phenolic Hop Extracts in Creating a New Pâté: An Element Affecting Fat Stability and Microbiological Quality during Storage

The aim of this study was to evaluate the effect of hop extracts on changes in the primary and secondary fat oxidation products, physicochemical properties, and microbiological quality of pâté-type offal sausages obtained through the partial replacement of animal fat with vegetable fat. This study demonstrated that the extraction efficiency varied among hop cone varieties, with the highest efficiency observed for the Lubelski variety and the lowest for the Magnum variety. The phenolic compound content was higher in the Magnum cones (2.74 ± 0.11 mg/g dry matter) compared to the Lubelska cones (2.27 ± 0.05 mg/g of product). Additionally, the DPPH radical scavenging activity was greater in the extract from the Magnum cones (4.21 ± 0.09 mg TE/g d.w.) than in the extract from the Lublelski cones (3.87 ± 0.05 mg TE/ g d.w.). Similarly, the extracts from the Lubelski cones exhibited a higher antiradical activity against the ABTS radical compared to the extract from Magnum cones. Throughout storage, a significant increase in the pH value was observed in the control sample and in the samples with a 20% replacement of animal fat with rapeseed oil and Magnum hop extract. However, the addition of Lubelski hop extract resulted in a decrease in the pH value during the 15-day storage period. The samples with a 20% replacement of animal fat with rapeseed oil and 0.1% Lubelski hop extract showed the least changes in water activity during storage. The samples with a 20% replacement of animal fat with rapeseed oil and the addition of 0.2% Lubelski hop extract had the lowest peroxide value and TBARS index throughout the storage period. The addition of hop extract inhibited the growth of the total number of microorganisms in the tested sausages. In the samples with a 20% replacement of animal fat with rapeseed oil, the content of aerobic microorganisms, compared to the control sample, was statistically significantly lower.

Washed microbiota transplantation for Crohn's disease: A metagenomic, metatranscriptomic, and metabolomic-based study

BACKGROUND

Fecal microbiota transplantation (FMT) is a promising therapeutic approach for treating Crohn's disease (CD). The new method of FMT, based on the automatic washing process, was named as washed microbiota transplantation (WMT). Most existing studies have focused on observing the clinical phenomena. However, the mechanism of action of FMT for the effective management of CD-particularly in-depth multi-omics analysis involving the metagenome, metatranscriptome, and metabolome-has not yet been reported.

AIM

To assess the efficacy of WMT for CD and explore alterations in the microbiome and metabolome in response to WMT.

METHODS

We conducted a prospective, open-label, single-center clinical study. Eleven CD patients underwent WMT. Their clinical responses (defined as a decrease in their CD Activity Index score of > 100 points) and their microbiome (metagenome, metatranscriptome) and metabolome profiles were evaluated three months after the procedure.

RESULTS

Seven of the 11 patients (63.6%) showed an optimal clinical response three months post-WMT. Gut microbiome diversity significantly increased after WMT, consistent with improved clinical symptoms. Comparison of the metagenome and metatranscriptome analyses revealed consistent alterations in certain strains, such as Faecalibacterium prausnitzii, Roseburia intestinalis, and Escherichia coli. In addition, metabolomics analyses demonstrated that CD patients had elevated levels of various amino acids before treatment compared to the donors. However, levels of vital amino acids that may be associated with disease progression (e.g., L-glutamic acid, gamma-glutamyl-leucine, and prolyl-glutamine) were reduced after WMT.

CONCLUSION

WMT demonstrated therapeutic efficacy in CD treatment, likely due to the effective reconstruction of the patient's microbiome. Multi-omics techniques can effectively help decipher the potential mechanisms of WMT in treating CD.

Synthesis of β-acids loaded chitosan-sodium tripolyphosphate nanoparticle towards controlled release, antibacterial and anticancer activity

The development of nanoparticles loaded with natural active ingredients is one of the hot trends in the pharmaceutical industry. Herein, chitosan was selected as the base material, and sodium tripolyphosphate was chosen as the cross-linking agent. Chitosan nanoparticles loaded with β-acids from hops were prepared by the ionic cross-linking method. The results of Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) indicated that chitosan nanoparticles successfully encapsulated β-acids. The loading capacity of chitosan nanoparticles with β-acids was 2.00 %-18.26 %, and the encapsulation efficiency was 0.58 %-55.94 %. Scanning electron microscopy (SEM), transmission electron microscope (TEM), particle size, and zeta potential results displayed that the nanoparticles revealed a sphere-like distribution with a particle size range of 241-261 nm, and the potential exhibited positive potential (+14.47-+16.27 mV). The chitosan nanoparticles could slowly release β-acids from different simulated release media. Notably, the β-acids-loaded nanoparticles significantly inhibited Staphylococcus aureus ATCC25923 (S. aureus) and Escherichia coli ATCC25922 (E. coli). Besides, β-acids-loaded chitosan nanoparticles were cytotoxic to colorectal cancer cells (HT-29 and HCT-116). Therefore, applying chitosan nanoparticles can further expand the application of β-acids in biomedical fields.

Green Synthesis of Zein-Based Nanoparticles Encapsulating Lupulone: Antibacterial and Antiphotoaging Agents

Prolonged skin exposure to UV radiation may result in sunburn, with possible inflammatory and oxidative stress to the skin, skin photoaging, photocarcinogenesis, even DNA damage, and apoptosis if sunscreen protection is not used. Due to the advantages that they offer, high encapsulation capability, increased stability of encapsulated bioactive agents, and release control, nanoparticulate materials have been used in sunscreens despite the hazard that they present: their capacity to penetrate the skin causing toxic side effects (especially the chemical sunscreens). The present study reports the preparation of nanoparticulate composites containing only GRAS substances and using an eco-friendly, inexpensive procedure. The ingredients used have properties that are beneficial to the skin. Zein (Z), a prolamin-rich protein from corn, is biodegradable and biocompatible, is a moisture attractor, and shows effective absorption by cells. Lupulone (L), extracted from hops, is an antibacterial and antioxidant agent that has a stimulating effect on the collagen production in the body due to its content of phytohormones. Gum arabic (GA) is a natural glycoprotein used in beverages and cosmetics as an emulsifier/stabilizer. Composite matrices containing Z/GA/L were prepared using a simple method (antisolvent), which replaces the flammable solvent ethanol with aqueous propylene glycol. The nanocomposites were characterized by FTIR, composition, encapsulation efficiency, and loading capacity for L, size, zeta potential, and morphology (SEM). Their biological activity was investigated as well. The zein-based nanoparticles showed antioxidant and antimicrobial effects (even some synergistic, unexpected behavior) and modulatory activity on the matrix metalloproteinase MMP-1. Due to their properties, the nanoparticles discussed herein show potential for use in formulations for the skin, especially for mature skin, replacing chemical substances with potential side effects used typically in topical delivery systems.