Untargeted metabolomics description of propolis's in vitro antibacterial mechanisms against Clostridium perfringens

Effects of drinking water supplemented with essential oils and organic acids mixtures on growth performance and intestinal health of broilers challenged with necrotic enteritis

It is urgent to develop effective antibiotic alternatives for the control of subclinical necrotic enteritis (NE) in chickens after in-feed antibiotics have been banned. The current study investigated the efficacy of drinking water supplemented with essential oils and organic acids mixtures (EOA) on growth performance and intestinal health of broilers challenged with necrotic enteritis (NE). A total of 360 one-day-old Arbor Acres male broilers were randomly divided into 5 treatment groups, including non-challenged control group (T0), challenged NE group (T1), and challenged NE chickens treated with 0.2 % EOA1 (T2) or 0.2 % EOA2 (T3) in drinking water, along with NE-challenged chickens treated with 45 mg/kg bacitracin methylene disalicylate (BMD) in the diet (T4). Results showed that drinking water supplemented with either EOA1 or EOA2 significantly decreased Clostridium perfringens load in ileal content (P < 0.05). EOA2 markedly reduced jejunal crypt depth, serum lipopolysaccharide (LPS) content, ileal IL-1β mRNA level and myeloperoxidase (MPO) activity, significantly increased Mucin-2 mRNA abundance in ileum of NE infected broilers (P < 0.05) when compared with single NE-infected group. The 16S sequencing analysis revealed that, compared with single NE-challenge group and the antibiotic BMD group, the addition of EOA1 in drinking water significantly increased the Shannon index and Simpson index of ileal microbiota in NE-infected broilers (P < 0.05), while drinking water supplemented with either EOA1 or EOA2 significantly decreased Streptococcus relative abundance of NE-infected broilers (P < 0.05). In summary, drinking water with EOA2 might alleviate the intestinal injury induced by NE challenge, and the gut health-improving effects of EOA2 were better than that of EOA1.

Characteristics of Indonesian Stingless Bee Propolis and Study of Metabolomic Properties Based on Region and Species

The chemical compounds found in propolis vary according to plant sources, species, and geographical regions. To date, Indonesian propolis has not yet become standardized in terms of its chemical constituents. Thus, this study aimed to identify the presence of marker compounds and determine whether different classes of Indonesian propolis exist. In this study, yields, total polyphenol content (TPC), total flavonoid content (TFC), and antioxidants were measured. Identification of chemical compounds was carried out with Fourier-transform infrared (FTIR) spectroscopy and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Metaboanalyst 6.0 was employed in conducting principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) using the results of the FTIR and LC-MS/MS. The propolis with the highest TFC, TPC, and antioxidant activity was Geniotrigona thoracica from North Sumatra. The results of propolis compound mapping based on region with discriminant analysis revealed that types of propolis from Java have similar characteristics. Then, based on species, the types of propolis from Tetragonula laeviceps and Heterotrigona itama have special characteristics; the samples from these species can be grouped according to similar characteristics. In conclusion, 10 potential marker compounds were identified in Indonesian propolis, enabling regional and species-specific varieties of Indonesian propolis to be classified based on chemical composition mapping.

Antibacterial activity and mechanism of luteolin isolated from Lophatherum gracile Brongn. against multidrug-resistant Escherichia coli

Infections caused by multidrug-resistant (MDR) bacteria have become a major challenge for global healthcare systems. The search for antibacterial compounds from plants has received increasing attention in the fight against MDR bacteria. As a medicinal and edible plant, Lophatherum gracile Brongn. (L. gracile) has favorable antibacterial effect. However, the main antibacterial active compound and its antimicrobial mechanism are not clear. Here, our study first identified the key active compound from L. gracile as luteolin. Meanwhile, the antibacterial effect of luteolin was detected by using the broth microdilution method and time-kill curve analysis. Luteolin can also cause morphological structure degeneration and content leakage, cell wall/membrane damage, ATP synthesis reduction, and downregulation of mRNA expression levels of sulfonamide and quinolones resistance genes in multidrug-resistant Escherichia coli (MDR E. coli). Furthermore, untargeted UPLC/Q-TOF-MS-based metabolomics analysis of the bacterial metabolites revealed that luteolin significantly changed riboflavin energy metabolism, bacterial chemotaxis cell process and glycerophospholipid metabolism of MDR E. coli. This study suggests that luteolin could be a potential new food additive or preservative for controlling MDR E. coli infection and spread.

Metabolomics and network pharmacology reveal the mechanism of Castanopsis honey against Streptococcus pyogenes

Streptococcus pyogenes (GAS) is one of the most virulent and infectious bacteria, severely threatening health and lives of people worldwide. Honey has been proven to have effective capability against GAS, but the underlying metabolites and mechanisms are still unclear. In this study, the Castanopsis honey (CH) showed significant antibacterial ability compared to other seven kinds of honey and artificial honey. Furthermore, the antibacterial metabolites and their targets in CH were screened by combined method of metabolomics, network pharmacology, and molecular docking. The results suggested that the activities of two antioxidant enzymes, glutathione peroxidase and tyrosyl tRNA synthetase identified as the primary targets, were significantly inhibited by CH, which significantly increased the level of oxidative stress in GAS. The results revealed a possibly novel mechanism regulating the oxidative stress and inhibits the growth in bacteria, providing strong experimental evidence to support the further development of CH as a novel antibacterial agent.

Macroporous resin purification of phenolics from Irish apple pomace: Chemical characterization, and cellular antioxidant and anti-inflammatory activities

Apple pomace (AP) is a highly prevalent waste product worldwide in the fruit processing sector. This study compared the chemical profile, antioxidant, and anti-inflammatory activities of crude (CE) and an extract purified using XAD-7 resin (PE). The purification process increased the total phenolic content, flavonoids, and tannins by 3.35, 40.31, and 8.87-fold, respectively. The main phenolic compounds identified in PE were phlorizin (20.54 mg/g), chlorogenic acid (10.01 mg/g), and hyperoside (2.77 mg/g). No difference was found between CE and PE in protecting human plasma against oxidation. In human erythrocytes, both CE and PE decreased the reactive oxygen species (ROS) generation and decreased lipoperoxidation. However, PE had stronger anti-inflammatory effects than CE by promoting HO-1 gene expression, suppressing NO production, and inhibiting IL-1β, IL-6, and IL-10 mRNA expression in lipopolysaccharide-challenged RAW.264.7 macrophages. Therefore, purifying apple pomace crude extract is a promising approach to boosting valuable antioxidants and anti-inflammatory phenolics.

Precise prediction of metabolites patterns using machine learning approaches in distinguishing honey and sugar diets fed to mice

As a natural sweetener produced by honey bees, honey was recognized as being healthier for consumption than table sugar. Our previous study also indicated thatmetaboliteprofiles in mice fed honey and mixedsugardiets aredifferent. However, it is still noteworthy about the batch-to-batch consistency of the metabolic differences between two diet types. Here, the machine learning (ML) algorithms were applied to complement and calibrate HPLC-QTOF/MS-based untargeted metabolomics data. Data were generated from three batches of mice that had the same treatment, which can further mine the metabolite biomarkers. Random Forest and Extra-Trees models could better discriminate between honey and mixed sugar dietary patterns under five-fold cross-validation. Finally, SHapley Additive exPlanations tool identified phosphatidylethanolamine and phosphatidylcholine as reliable metabolic biomarkers to discriminate the honey diet from the mixed sugar diet. This study provides us new ideas for metabolomic analysis of larger data sets.

Effect of propolis extract addition on some physicochemical, microbiological, and sensory properties of kefir drinks

Kefir drinks with sugar (5%, w/v), strawberry flavor (0.15%, v/v), and propolis extract (PE) at different ratios (0.150%, 0.225%, and 0.300%, v/v) were produced and stored at 4°C, and their physicochemical, rheological, microbiological, and sensory properties were monitored during storage. The ratio of PE and storage time had an insignificant effect on the dry matter, protein, fat contents, Commission Internationale de l'Eclairage (CIE) L* and a* color values, apparent viscosity, consistency coefficient, flow behavior index, Lactobacillus spp., Lactococcus spp., and yeast counts of kefir drinks (p > .05). The CIE b* values of kefir drinks increased with an increase in PE ratio (p < .05). All kefir samples exhibited a pseudoplastic flow behavior. Initially, the total antioxidant capacity of kefir drinks was 2.19 μmol TE/100 mL, which increased to 2.51 μmol TE/100 mL for kefir drinks with 0.225% PE. The total phenolic content and antioxidant capacity of kefir drinks with PE decreased during storage. PE addition did not influence the sensory color and taste liking scores of kefir drinks adversely until the 8th day of storage. In terms of odor liking scores, kefir drinks with 0.225% and 0.300% PE had a similar score to control drinks. Additionally, kefir drinks with 0.150% and 0.225% PE received an overall liking score similar to control drinks. Results indicated that the incorporation of PE at a ratio of 0.225% was recommended for the production of strawberry-flavored kefir drinks with acceptable sensory characteristics and increased functional properties, and this product could be stored for up to 8 days.

Integration with Transcriptomic and Metabolomic Analyses Reveals the In Vitro Cytotoxic Mechanisms of Chinese Poplar Propolis by Triggering the Glucose Metabolism in Human Hepatocellular Carcinoma Cells

Natural products serve as a valuable reservoir of anticancer agents. Chinese poplar propolis (CP) has exhibited remarkable antitumor activities, yet its precise mechanisms of action remain elusive. This study aims to elucidate the in vitro cytotoxic mechanisms of CP in human hepatocellular carcinoma cells (HepG2) through comprehensive transcriptomic and metabolomic analyses. Our evidence suggested that CP possesses a great potential to inhibit the proliferation of HepG2 cells by targeting the glucose metabolism. Notably, CP exhibited a dose- and time-dependent reduction in the viability of HepG2 cells. Transcriptome sequencing unveiled significant alterations in the cellular metabolism, particularly within glucose metabolism pathways. CP effectively restrained glucose consumption and lactic acid production. Moreover, the CP treatment led to a substantial decrease in the mRNA expression levels of key glucose transporters (GLUT1 and GLUT3) and glycolytic enzymes (LDHA, HK2, PKM2, and PFK). Correspondingly, CP suppressed some key protein levels. Cellular metabolomic analysis demonstrated a marked reduction in intermediary products of glucose metabolism, specifically fructose 1,6-bisphosphate and acetyl-CoA, following CP administration. Finally, key compounds in CP were screened, and apigenin, pinobanksin, pinocembrin, and galangin were identified as potential active agents against glycolysis. It indicates that the effectiveness of propolis in inhibiting liver cancer is the result of the combined action of several components. These findings underscore the potential therapeutic value of propolis in the treatment of liver cancer by targeting glycolytic pathways.

Severe pathological changes in the blood and organs of SD rats stung by honeybees

With the development of beekeeping, the risk of bee stings in humans is increasing. Severe and life-threatening toxic reactions can occur after multiple bee stings, and their pathogenesis has not been elucidated. To understand the effect of multiple bees (Apis mellifera) stings on the organism in a short period, we stung rats once and five times, respectively. Serum and organs were obtained after 3 h for analysis. The results indicated that skin erythema was more pronounced and hemolysis was more severe as the number of puncture wounds increased. After being stung by five bees, rats had dramatically higher serum levels of direct bilirubin, aspartate aminotransferase, creatine kinase and lactate dehydrogenase, producing more differential metabolites that affected mainly four metabolic pathways. In addition, the liver, kidney and heart showed significant congestion and inflammation. This study helps explain the organism's clinical response to bee venom and may be valuable in treating toxic reactions following bee stings.