Characteristics of endophytic bacteria and active ingredients in the Eucommiae cortex from different origins

Preparation techniques, structural features, and bioactivities of Eucommia ulmoides polysaccharides: A review

Eucommia ulmoides Oliv. (tu-chung), as a famous nature medical and edible plant, has the effect of tonifying liver and kidney, strengthening the function of the muscles and bones, and miscarriage prevention. Accumulating evidence has demonstrated that the polysaccharides from Eucommia ulmoides Oliv. (EUPs) are a kind of vital and representative biologically active macromolecules and have various health-promoting biological activities in vivo and in vitro, such as antioxidant activity, immunomodulatory activity, hypolipidemic and hypoglycemic activities, anti-inflammatory activities, anti-tumor activity, and among others. The review aims to comprehensively and systematically collate the recent research progress on extraction and purification methods, structural characteristics, biological activities, mechanism of action, structural modification, and toxicity of EUPs to support their therapeutic potential and health-care functions. New valuable insights for future research with EUPs were also proposed in the areas of structural characterization and pharmacological activities to promoting the development of therapeutic agents and functional foods.

Insight into saffron associated microbiota from different origins and explore the endophytes for enhancement of bioactive compounds

Crocus sativus L. is a perennial crop for its valuable active compounds. Plant-associated microbes impact on the quality and efficacy of medicinal herbs by promoting bioactive components accumulation. However, how microbes influence the accumulation of bioactive components in saffron have not been well studied. Here, the microbiome in C. sativus derived from 3 core production areas were deciphered by 16S rDNA sequencing and the relationship between endophytes and bioactive ingredients were further investigated. The main results are as follows: (1) Both Comamonadaceae and Burkholderiaceae were positively correlated with the content of bioactive components in the stigmas. (2) The synthesis of crocin was positively correlated with Xanthomonadaceae, negatively correlated with Lachnospiraceae and Prevotellaceae. Therefore, further investigation is required to determine whether Xanthomonadaceae plays an unknown function in the synthesis of crocin. These findings provide guidelines for disentangling the function of endophytes in the production of bioactive ingredients and thus for microbe-mediated breeding.

The accumulation of active ingredients of Polygonatum cyrtonema Hua is associated with soil characteristics and bacterial community

Introduction

With the increasing demand for health products derived from Polygonati rhizoma (PR), people begin to artificially plant Polygonatum cyrtonema Hua (P. cyrtonema) in the middle and lower reaches of the Yangtze River. To promote P. cyrtonema cultivation and increase farmers' income, efforts are needed to understand the ways to obtain high-quality PR under artificial cultivation conditions.

Methods

Rhizomes of artificial planting P. cyrtonema and rhizosphere soils were collected across five regions in Zhejiang Province, China. Subsequently, the contents of the main active ingredients of P. cyrtonema and soil properties were analyzed, and both rhizosphere and endophytic bacteria of P. cyrtonema were detected by 16S rDNA sequencing. The relationship between the active ingredients and soil properties, and the dominant bacteria were investigated by correlation analysis.

Results

The content of active ingredients of P. cyrtonema from the five regions varied significantly, especially polysaccharides and saponins. High-throughput sequencing demonstrated that Proteobacteria was the dominant bacterial phylum in all samples, and Burkholderia-Caballeronia-Paraburkholderia was the main endophytic bacterial genus in rhizome. In addition, the bacterial diversity and richness of rhizosphere soil samples were higher than those of rhizome samples. Soil physicochemical properties and enzyme activities were significantly different across regions, leading to notable variations in the community structures of rhizosphere and endophytic bacteria. Redundancy analysis (RDA) displayed that pH and urease (UE) were the major factors altering shifting rhizosphere bacteria community structure. Moreover, the composition and diversity of rhizome endophytic bacteria were principally affected by both soil physicochemical properties and soil enzyme activities. Soil properties and bacteria from rhizosphere soil and rhizome had a considerable impact on certain active ingredients in P. cyrtonema under artificial cultivation conditions after Pearson correlation analysis. Polysaccharides were significantly correlated with nutrient-rich soil and endophytic bacteria, such as Burkholderia-Caballeronia-Paraburkholderia, Pseudomonas, Ralstonia, and Bacillus. However, flavonoids were associated with nutrient-poor soil. Saponins were positively correlated with OM and available phosphorous (AP) and were significantly negatively affected by rhizosphere bacterial communities.

Conclusion

The study demonstrated that bacterial microorganisms were involved in the accumulation of active ingredients of P. cyrtonema together with soil physicochemical properties and enzyme activities, which provided a theoretical basis for the scientific and effective artificial cultivation of high-quality P. cyrtonema.

Dynamic changes of endophytic bacteria in the bark and leaves of medicinal plant Eucommia ulmoides in different seasons

The bark and leaves of the Eucommia ulmoides Oliv. (E. ulmoides) have good medicinal value. Studies show endophytes play important roles in host medicinal plant secondary metabolite synthesis, with season being a key influencing factor. Therefore, we used 16 S rRNA to detect endophytic bacteria (EB) in E. ulmoides bark and leaves collected in winter, spring, summer, and autumn, and analyzed the contents of major active components respectively. The results showed that the species diversity and richness of EB of the E. ulmoides bark were higher than those of leaves in all seasons except fall. Among them, the higher species diversity and richness were found in the E. ulmoides bark in winter and spring. EB community structure differed significantly between medicinal tissues and seasons. Concurrently, the bark and leaves of E. ulmoides showed abundant characteristic EB across seasons. For active components, geniposidic acid showed a significant positive correlation with EB diversity and richness, while the opposite was true for aucubin. Additionally, some dominant EB exhibited close correlations with the accumulation of active components. Delftia, enriched in autumn, correlated significantly positively with aucubin. Notably, the impact of the same EB genera on active components differed across medicinal tissues. For example, Sphingomonas, enriched in summer, correlated significantly positively with pinoresinol diglucoside (PDG) in the bark, but with aucubin in the leaves. In summary, EB of E. ulmoides was demonstrated high seasonal dynamics and tissue specificity, with seasonal characteristic EB like Delftia and Sphingomonas correlating with the accumulation of active components in medicinal tissues.

Bifidobacterium animalis subsp. lactis F1-7 Alleviates Lipid Accumulation in Atherosclerotic Mice via Modulating Bile Acid Metabolites to Downregulate Intestinal FXR

The dysfunction of intestinal microbiota and bile acid metabolism is related to the pathogenesis of atherosclerosis. This study we explored the mechanism of Bifidobacterium animalis subsp. lactis F1-7 (Bif. animalis F1-7), improving atherosclerosis by regulating the bile acid metabolism and intestinal microbiota in the ApoE-/- mice. The Bif. animalis F1-7 effectively reduced aortic plaque accumulation and improved the serum and liver lipid levels in atherosclerotic mice. The untargeted metabolomics revealed that Bif. animalis F1-7 reduced the glycine-conjugated bile acids and the levels of differential metabolite lithocholic acid (LCA) significantly. Downregulation of LCA decreased the intestinal levels of the farnesoid X-activated receptor (FXR) and regulated the bile acid metabolism through the FXR/FGF15/CYP7A1 pathway. Furthermore, the 16srRNA gene sequencing analysis revealed that structural changes in intestinal microbiota with an increase in the abundance of Bifidobacterium, Lactobacillus, Faecalibaculum, Desulfovibrio, and a decrease in Dubosiella, Clostridium_sensu_stricto_1, and Turicibacter following the Bif. animalis F1-7 intervention. Correlation analysis showed that the changes in intestinal microbiota mentioned above were significantly correlated with bile acid metabolism in atherosclerotic mice. In conclusion, this study sheds light on the mechanisms by which Bif. animalis F1-7 regulates atherosclerosis.

Combination of a Deep Eutectic Solvent and Macroporous Resin for Green Recovery of Iridoids, Chlorogenic Acid, and Flavonoids from Eucommia ulmoides Leaves

To increase the effectiveness of using typical biomass waste as a resource, iridoids, chlorogenic acid, and flavonoids from the waste biomass of Eucommia ulmoides leaves (EULs) were extracted by deep eutectic solvents (DESs) in conjunction with macroporous resin. To optimize the extract conditions, the experiment of response surface was employed with the single-factor of DES composition molar ratio, liquid-solid ratio, water percentage, extraction temperature, and extraction time. The findings demonstrated that the theoretical simulated extraction yield of chlorogenic acid (CGA), geniposidic acid (GPA), aucubin (AU), geniposide (GP), rutin (RU), and isoquercetin (IQU) were 42.8, 137.2, 156.7, 5.4, 13.5, and 12.8 mg/g, respectively, under optimal conditions (hydrogen bond donor-hydrogen bond acceptor molar ratio of 1.96, liquid-solid ratio of 28.89 mL/g, water percentage of 38.44%, temperature of 317.36 K, and time of 55.59 min). Then, 12 resins were evaluated for their adsorption and desorption capabilities for the target components, and the HPD950 resin was found to operate at its optimum. Additionally, the HPD950 resin demonstrated significant sustainability and considerable potential in the recyclability test. Finally, the hypoglycemic in vitro, hypolipidemic in vitro, immunomodulatory, and anti-inflammatory effects of EUL extract were evaluated, and the correlation analysis of six active components with biological activity and physicochemical characteristics of DESs by heatmap were discussed. The findings of this study can offer a theoretical foundation for the extraction of valuable components by DESs from waste biomass, as well as specific utility benefits for the creation and development of natural products.

Extraction and Purification of Aucubin from Eucommia ulmoides Seed Draff in Natural Deep Eutectic Solvents Using Macroporous Resins

Aucubin (AU) is an active ingredient that exerts strong antioxidant and anti-inflammatory effects in the treatment of several diseases. In order to improve the efficiency of resource utilization of traditional biomass waste, Eucommia ulmoides seed-draff (EUSD) waste biomass was used as the raw material, and a series of deep eutectic solvents were selected to evaluate the extraction efficiency of aucubin from EUSD. A response surface experiment was designed based on a single-factor experiment to optimize the extract conditions. The results showed that the best conditions for aucubin extraction were an HBD-HBA ratio of 2.18, a liquid-solid ratio of 46.92 mL/g, a water percentage of 37.95%, a temperature of 321.03 K, and an extraction time of 59.55 min. The maximum amount of aucubin was 156.4 mg/g, which was consistent with the theoretical value (156.8 mg/g). Then, the performance of 12 resins for adsorption and desorption was contrasted. The results revealed that HPD950 resin exhibited the best performance, with an adsorption capacity of 95.2% and a desorption capacity of 94.3%. Additionally, the pseudo-second-order model provided the best match to the kinetics data, the Langmuir model provided the best fit to the isotherm data, and adsorption was a beneficial, spontaneous, exothermic, and physical process. In the recyclability test, the HPD950 resin had great potential and excellent sustainability in aucubin recovery. In the antioxidant activity study, the aucubin extract exerted a strong antioxidant ability with scavenging capabilities for four free radicals. Furthermore, the antifungal activity study found that the aucubin extract exhibited a good antifungal effect against 5 tested pathogens. The research results can provide a theoretical basis for the extraction of high-value components from waste biomass by deep eutectic solvent and a certain application value for the development and utilization of natural aucubin products.