Cellulase-assisted extraction and antibacterial activity of polysaccharides from the dandelion Taraxacum officinale

Microwave-assisted extraction of dandelion root polysaccharides: Extraction process optimization, purification, structural characterization, and analysis of antioxidant activity

This study aimed to establish a microwave-assisted method (MAE) for the efficient extraction of polysaccharides from dandelion roots. This study investigated the molecular structure and bioactivity of the polysaccharides from dandelion roots. Extraction conditions were optimized using response surface methodology (RSM). The microwave extraction conditions were set to an extraction time of 42 min, an extraction temperature of 80 °C, and a solid-liquid ratio (g/mL) of 1:33. Under the optimized conditions, the highest dandelion root polysaccharides (DRP) yield was achieved (24.85 ± 0.457 %). Water-pure DRP (DRPw) and NaCl-pure DRP (DRPs) were purified by activated carbon decolorization and DEAE fiber column chromatography. The molecular weights of DRPw and DRPs were 8653 Da and 5930 Da, respectively. The Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) analyses confirmed the existence of α- and β-pyranose in DRPw and DRPs. The results of X-ray diffraction (XRD) and scanning electron microscopy (SEM) showed that DRPw and DRPs were semi-crystalline substances with irregular shapes and rough surfaces. Bioactivity assays revealed the good antioxidant activities of DRPw and DRPs. The present study provides useful information about DRP as natural antioxidants for the benefit of food.

Effects of different extraction temperatures on the structural characteristics and antioxidant activity of polysaccharides from dandelion leaves

Dandelion polysaccharides contribute to a variety of biological activities. This study evaluated the effect of different extraction temperatures (4 °C and 80 °C) on the structural characteristics and antioxidant activity of dandelion leaf polysaccharides (DLP). The findings demonstrated that the extraction efficiency improved at the higher temperature, while molecular weight exist a trend of degradation with increasing extraction temperature. Ion chromatography (IC) analysis indicated that the polysaccharides DLP4 and DLP80 were structurally complex heteropolysaccharides mainly composed of galactose, arabinose, glucose and mannose, with galactose and arabinose dominating. FT-IR and methylation analysis revealed that DLP4 and DLP80 had similar chemical structures and branches. DLP4 contained a higher amount of 6-Galactose. Microstructure analysis showed that heat treatment caused conformational changes in DLP4 and DLP80. Both had excellent free radical scavenging ability including DPPH·, ABTS·+, OH· and reducing power. The Reactive Oxygen Species assay indicated that the protective effect of DLP4 against H2O2-induced oxidative damage in vitro was stronger than that of DLP80. Superoxide dismutase (SOD) and malondialdehyde (MDA) measurements also confirmed that the antioxidant effect of DLP4 was more prominent. Overall, low temperature extracted DLP can be used as an antioxidant in the areas of food, medicine and biomaterials.

The phytochemical and pharmacological profile of dandelion

Dandelion (Taraxacum genus), a perennial herb belonging to the Asteraceae family is widely distributed in hillside grasslands, roadsides, fields, and river beaches in middle and low-altitude areas. It has a long history of traditional Chinese medicine usage as a heat-clearing and detoxifying agent, often consumed as tea or vegetable. Multiple pharmacological studies have demonstrated the antiviral, antibacterial, anti-inflammatory, immune-regulating, antioxidant, anti-tumor, and other effects of the Taraxacum genus. Bioactive compounds associated with these effects include triterpenes and their saponins, phenolic acids, sterols and their glycosides, flavonoids, organic acids, volatile oils, and saccharides.

Plant-mediated Z-scheme ZnO/TiO2-NCs for antibacterial potential and dye degradation: experimental and DFT study

Efficient separation of electron-hole pairs remains pivotal in optimizing photogenerated carrier functionality across diverse catalytic and optoelectronic systems. This study presents the fabrication of a novel hollow direct Z-scheme photocatalyst, ZnO/TiO2. A thorough analysis encompassing various techniques such as Ultraviolet-Visible Spectroscopy (UV-Vis), X-ray Diffraction (XRD), Transmission electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA), and Energy-Dispersive X-ray Spectroscopy (EDX) provided detailed insights into the complex material characteristics of the ZnO/TiO2 heterojunction catalyst. The findings revealed coexisting anatase TiO2 and wurtzite ZnO phases, each retaining distinct attributes within the nanocomposites (NCs) structure. The study showcased the photocatalytic efficacy of ZnO/TiO2-NCs in decomposing Methylene Blue and Acridine Orange under UV irradiation, correlated with their underlying structures. Enhanced degradation of these dyes resulted from the establishment of a direct Z-scheme heterojunction between ZnO and TiO2. Employing Density Functional Theory (DFT) using Quantum ESPRESSO, this research analyzed phase diagrams and band structures, elucidating electronic properties and structural correlations. The study characterized a ZnO/TiO2 composite, revealing a band gap of 3.1-3.3 eV through UV-Visible spectroscopy and confirming its formation without impurity phases via XRD analysis. TEM and EDX showed uniform element dispersion (Zn: 27%, Ti: 29.62%, C: 5.03%, O: 38.35%). Computational analysis using DFT indicated a reduction in stable phases with increasing temperature. Enhanced dye degradation was observed (MB: 88.9%, AO: 84%), alongside significant antibacterial activity. In the future we predict that research will focus on development of scaled up production and photocatalytic activity through surface modification, while unveiling mechanistic insights and environmental applicability for multifunctional use in water treatment and antibacterial applications, leading to further advancement of the field.

Taraxacum: A Review of Ethnopharmacology, Phytochemistry and Pharmacological Activity

Taraxacum refers to the genus Taraxacum, which has a long history of use as a medicinal plant and is widely distributed around the world. There are over 2500 species in the genus Taraxacum recorded as medicinal plants in China, Central Asia, Europe, and the Americas. It has traditionally been used for detoxification, diuresis, liver protection, the treatment of various inflammations, antimicrobial properties, and so on. We used the most typically reported Taraxacum officinale as an example and assembled its chemical makeup, including sesquiterpene, triterpene, steroids, flavone, sugar and its derivatives, phenolic acids, fatty acids, and other compounds, which are also the material basis for its pharmacological effects. Pharmacological investigations have revealed that Taraxacum crude extracts and chemical compounds contain antimicrobial infection, anti-inflammatory, antitumor, anti-oxidative, liver protective, and blood sugar and blood lipid management properties. These findings adequately confirm the previously described traditional uses and aid in explaining its therapeutic applications.

Extraction, purification, structural features, biological activities, modifications, and applications from Taraxacum mongolicum polysaccharides: A review

Dandelion (Taraxacum mongolicum Hand.-Mazz), as a famous medicinal and edible plant, has the effects of clearing heat and detoxifying, diuresis, and resolving masses. Phytochemistry investigations revealed that T. mongolicum has various bioactive ingredients, mainly including flavonoids, sterols, polysaccharides, phenolic acids and volatile oils. There is growing evidence have shown that the polysaccharides from T. mongolicum (TMPs) are a class of representative pharmacologically bioactive macromolecules with a variety of biological activities both in vitro and in vivo, such as immunomodulatory, anti-inflammatory, anti-oxidant, anti-tumor, hepatoprotective, hypolipidemic and hypoglycemic, anti-bacterial, regulation of intestinal microbial, and anti-fatigue activities, etc. Additionally, the structural modification and potential applications of TMPs were also outlined. The present 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 potential industry applications of TMPs to support their therapeutic potential and health care functions. Overall, the present review provides a theoretical overview for further development and utilization of TMPs in the fields of pharmaceutical and health food.

Inhibition of IEC-6 Cell Proliferation and the Mechanism of Ulcerative Colitis in C57BL/6 Mice by Dandelion Root Polysaccharides

An exploration was conducted on the potential therapeutic properties of dandelion polysaccharide (DP) in addressing 3% dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) in murine models. Subsequent assessments focused on DP's influence on inflammation, oxidative stress, and ferroptosis in IEC-6 cells damaged by H2O2. Results highlighted the efficacy of DP in mitigating weight loss, improving disease activity index scores, normalizing colon length, and alleviating histological abnormalities in the affected mice. DP repaired colonic mitochondrial damage by enhancing iron transport and inhibited iron death in colonic cells. Moreover, DP played a pivotal role in enhancing the antioxidant potential. This was evident from the increased expression levels of Nrf2, HO-1, NQO-1, and GSH, coupled with a decrease in MDA and 4-HNE markers in the UC-afflicted mice. Concurrently, DP manifested inhibitory effects on MPO activation and transcription levels of inflammatory mediators such as IL-1β, IL-6, TNF-α, and iNOS. An upsurge in the expression of occludin and ZO-1 was also observed. Restoration of intestinal tightness resulted in decreased serum LPS and LDH levels. Thereafter, administration of DP by gavage increased fecal flora diversity and relative abundance of probiotics in UC mice. Analysis of metabolites indicated that DP counteracted metabolic disturbances and augmented the levels of short-chain fatty acids in ulcerative colitis-affected mice. In vitro studies underscored the role of DP in triggering Nrf2 activation, which in turn exhibited anti-inflammatory, antioxidant, and anti-ferroptotic properties. Summarily, DP's capacity to activate Nrf2 contributes to the suppression of ferroptotic processes in intestinal epithelial cells of UC-affected mice, enhancing the intestinal barrier's integrity. Beyond that, DP possesses the ability to modulate the gut microbiome, rectify metabolic imbalances, rejuvenate short-chain fatty acid levels, and bolster the intestinal barrier as a therapeutic approach to UC.

Isolation of a New Polysaccharide from Dandelion Leaves and Evaluation of Its Antioxidant, Antibacterial, and Anticancer Activities

Dandelion, in China, has a long history as a medicinal and edible plant, and possesses high nutritional and medical value. The present study aimed to isolate a new polysaccharide (DLP-3) from dandelion leaves and to evaluate its antioxidant, antibacterial, and anticancer activities. The structure of DLP-3 was analyzed using HPLC, FT-IR, SEM, GC-MS, and NMR spectroscopy. DLP-3 mainly consisted of Man, Rha, GlcA, Glc, Gal, and Ara with molar ratios of 2.32, 0.87, 1.21, 3.84, 1.00, and 1.05, respectively, with a molecular weight of 43.2 kDa. The main linkages of DLP-3 contained (1→4)-α-d-Glc, (1→4,6)-α-d-Glc, (1→6)-α-d-Gal, (1→2)-α-d-Man, (1→4)-α-d-Man, β-l-Ara-(1→, and α-l-Rha-(1→. DLP-3 exhibited a smooth surface, purely flake-like structure, and a triple helix conformation. Moreover, DLP-3 presented obvious antioxidant and antibacterial activities in a concentration-dependent manner. DLP-3 showed significant anticancer activities by inhibiting tumor cell proliferation. These findings provide a theoretical basis for the application of DLP-3 as a natural functional active substance in functional foods.

The potential for traditional Chinese therapy in treating sleep disorders caused by COVID-19 through the cholinergic anti-inflammatory pathway

Since the outbreak of Coronavirus disease (COVID-19) in 2019, it has spread rapidly across the globe. Sleep disorders caused by COVID-19 have become a major concern for COVID-19 patients and recovered patients. So far, there's no effective therapy on this. Traditional Chinese therapy (TCT) has a great effect on sleep disorders, with rare side effects and no obvious withdrawal symptoms. The cholinergic anti-inflammatory pathway, a neuroregulatory pathway in the central nervous system that uses cholinergic neurons and neurotransmitters to suppress inflammatory responses, has been reported to be associated with sleep disorders and psychiatric symptoms. Many studies have shown that TCT activates the cholinergic anti-inflammatory pathway (CAP), inhibits inflammation, and relieves associated symptoms. Therefore, we believe that TCT may be a potential therapeutic strategy to alleviate sleep disorders induced by COVID-19 through CAP. In this review, we analyzed the relationship between cytokine storm induced by Coronavirus and sleep disorders, explained the influence of CAP on sleep disorders, discussed the TCT's effect on CAP, and summarized the treatment effect of TCT on sleep disorders. Based on these practical researches and theoretical basis, we propose potential strategies to effectively improve the sleep disorders caused by COVID-19.

The exploration of anti-Vibrio parahaemolyticus substances from Phellodendri Chinensis Cortex as a preservative for shrimp storage

This study aimed to optimize the ultrasonic-assisted extraction of the anti-Vibrio parahaemolyticus substances of Phellodendri Chinensis Cortex (ASPC), identify their active substances, and investigate their application in shrimp storage. The ultrasonic-assisted extraction conditions of ASPC were optimized through a single-factor experiment combined with response surface methodology. The optimal parameters were the ethanol concentration of 81%, the ultrasonic power of 500 W, the temperature of 80°C, the extraction time of 23 min, and the liquid/solid ratio 25 ml/g. The antibacterial zone diameter of the obtained extract determined by agar well diffusion method was 15.56 ± 0.22 mm, which was not significantly different from the predicted value (15.92 mm). Berberine was identified as one of the main chemical components of ASPC through high-performance liquid chromatography combined with standard control. The minimum inhibitory concentrations of ASPC and berberine determined by the tube dilution method were 0.25 and 0.03 mg/ml, respectively. The application of ASPC in shrimp storage showed that it could effectively inhibit the proliferation of V. parahaemolyticus on shrimps. This report offers good prospects for the use of Phellodendri Chinensis Cortex as a potential preservative against V. parahaemolyticus in aquatic products.

Effects of polystyrene nanoplastics on lead toxicity in dandelion seedlings

Increasing rates of commercialization and industrialization have led to the comprehensive evaluation of toxic effects of microplastics on crop plants. However, research on the impact of functionalized polystyrene nanoplastics on the toxicity of heavy metals remains limited. This study investigated the effects of polystyrene, carboxy-modified polystyrene, and amino-modified polystyrene on lead (Pb) toxicity in dandelion seedlings. The results showed that carboxy -modified polystyrene with a negative charge absorbed more Pb²⁺ than polystyrene and amino-modified polystyrene, and their maximum adsorption amounts were 5.328, 0.247, and 0.153 μg g^-1, respectively. The hydroponic experiment demonstrated that single amino-modified polystyrene was more toxic to dandelion seedlings than polystyrene and carboxy-modified polystyrene. The presence of Pb²⁺ was found to increase antioxidant enzymes (superoxide dismutase and catalase) and non-antioxidant enzymes (glutathione and ascorbic acid) activities in response to excessive reactive oxygen species in dandelion leaves and roots treated with polystyrene and carboxy-modified polystyrene, while it did not change much when amino-modified polystyrene was added. Interestingly, compared with single Pb²⁺, the addition of amino-modified polystyrene with positive charges induced an obvious decrease in the above parameters; however, they declined slightly in the treatments with polystyrene and carboxy-modified polystyrene despite a stronger adsorption capacity for Pb²⁺. Similarly, the bioactive compounds, including flavonoids, polyphenols, and polysaccharides in dandelion, showed a scavenging effect on O₂^- and H₂O₂, thereby inhibiting the accumulation and reducing medicinal properties. This study found that the effects of microplastics on the uptake, distribution, and toxicity of heavy metals depended on the nanoparticle surface charge.

Protective Effect of Fresh/Dry Dandelion Extracts on APAP-Overdose-Induced Acute Liver Injury

OBJECITVIE

To compare the liver protective activity of fresh/dried dandelion extracts against acetaminophen (APAP)-induced hepatotoxicity.

METHODS

Totally 90 Kunming mice were randomly divided into 10 groups according to body weight (9 mice for each group). The mice in the normal control and model (vehicle control) groups were administered sodium carboxymethyl cellulose (CMC-Na, 0.5%) only. Administration groups were pretreated with high and low-dose dry dandelion extract (1,000 or 500 g fresh herb dried and then decocted into 120 mL solution, DDE-H and DDE-L); low-, medium- and high-dose dandelion juice (250, 500, 1,000 g/120 mL, DJ-L, DJ-M, and DJ-H); fresh dandelions evaporation juice water (120 mL, DEJW); dry dandelion extract dissolved by pure water (1 kg/120 mL, DDED-PW); dry dandelion extract dissolved by DEJW (120 g/120 mL, DDED-DEJW) by oral gavage for 7 days at the dosage of 0.5 mL solution/10 g body weight; after that, except normal control group, all other groups were intraperitonealy injected with 350 mg/kg APAP to induce liver injury. Twenty hours after APAP administration, serum and liver tissue were collected and serum alanine aminotransferase (AST), aspartate transaminase (ALT), alkaline phosphatase (AKP), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD) activities were quantified by biochemical kits; tumor necrosis factor (TNF-α), interleukin (IL)-2, and IL-1 β contents in liver tissue were determined by enzyme linked immunosorbent assay kits. Histopathological changes in liver tissues were observed by hematoxylin and eosin staining; TUNEL Assay and Hoechst 33258 staining were applied for cell apoptosis evaluation. The expressions of heme oxygenase-1 (HO-1), nuclear factor erythroid-2-related factor 2 (Nrf-2), caspase-9, B-cell leukemia/lymphoma 2 (Bcl-2), Bax and p-JNK were determined by Western blot analysis.

RESULTS

Pretreatment with fresh dandelion juice (FDJ, including DJ-L, DJ-M, DJ-H, DEJW and DDED-DEJW) significantly decreased the levels of serum ALT, AST, AKP, TNF-α and IL-1β compared with vehicle control group (P<0.05 or P<0.01). Additionally, compared with the vehicle control group, FDJ decreased the levels of hepatic MDA and restored GSH levels and SOD activity in livers (P<0.05 or P<0.01). FDJ inhibited the overexpression of pro-inflammatory factors including cyclooxygenase-2 and inducible nitric oxide synthase in the liver tissues (P<0.05 or P<0.01). Furthermore, Western blot analysis revealed that FDJ pretreatment inhibited activation of apoptotic signaling pathways via decreasing of Bax, and caspase-9 and JNK protein expression, and inhibited activation of JNK pathway (P<0.05 or P<0.01). Liver histopathological observation provided further evidence that FDJ pretreatment significantly inhibited APAP-induced hepatocyte necrosis, inflammatory cell infiltration and congestion.

CONCLUSIONS

FDJ pretreatment protects against APAP-induced hepatic injury by activating the Nrf-2/HO-1 pathway and inhibition of the intrinsic apoptosis pathway, and the effect of fresh dandelion extracts was superior to dried dandelion extracts in APAP hepatotoxicity model mice.

Effects of Taraxacum mongolicum Hand.-Mazz. (dandelion) on growth performance, expression of genes coding for tight junction protein and mucin, microbiota composition and short chain fatty acids in ileum of broiler chickens

Background

Dandelion is becoming an exploitable alternative to the widely prohibited antibiotics in the poultry production. This research aimed to investigate the effects of dandelion on the growth performance and intestinal barrier function of broiler chickens maintained under standard condition of management. One-hundred and sixty 1-day-old Arbor Acres (AA) male broiler chickens were randomly divided into four groups, with five replicates of eight birds each. The birds were fed a basal diet supplemented without (control group, [CON]) or with 500 (low dose [LD]) or 1000 (high dose [HD]) mg/kg dandelion or with 250 mg/kg chlortetracycline 20% premix (CTC) for 42 days, including the starter phase (d 1 to 21) and the grower phase (d 22 to 42). Body weight (BW) of each bird and feed consumption of each replicate were measured at d 21 and d 42. The ileal tissues were collected on day 21 and 42 to determine expression of genes coding for tight junction protein and mucin as well as ELISA analysis for immune factor. The ileal digesta was collected for microbiota and short chain fatty acids analysis.

Results

Compared with CON group, during day 1–21, the average daily feed intake (ADFI) and feed/gain ratio (F/G) of LD group were lower (P < 0.05); during day 22–42, the F/G of LD and CTC group tended to be lower (P = 0.07); during the overall phase, the ADFI of HD and CTC groups were decreased (P < 0.05), and the F/G of dandelion and CTC groups tended to be decreased (P = 0.07). On day 21, the relative mRNA expression of claudin, occludin-1 and mucin1 in dandelion groups were up-regulated (P < 0.05), and the ZO-1 mRNA expression in CTC group was increased (P < 0.05); on day 42, the claudin and mucin1 transcripts in LD group and ZO-1 transcripts in HD and CTC group were up-regulated (P < 0.05), while the occludin-1 and mucin1 transcripts in CTC group was significantly down-regulated (P < 0.05). In addition, the contents of TNF-α in dandelion groups were lower than that in CTC group (P < 0.05). In the analysis of ileal microbiota, on day 21, decreased α-diversity was observed in HD and CTC groups (P < 0.05). Meanwhile, on day 21, the relative abundance of Firmicutes in dandelion groups tended to be higher (P = 0.09), the relative abundance of Lactobacillus in LD and CTC group were increased (P < 0.05), while Bacteroidete, Bacteroides, and Alistipes relative abundance in dandelion and CTC groups were decreased (P < 0.05). On day 42, the Actinobacteriota relative abundance in CTC group tended to be higher (P = 0.05), and Lysinibacillus relative abundance of CTC group was higher (P = 0.02). Compared with CON group, on day 21, the propionic acid and butyric acid content in CTC group were higher, the butyric acid content in HD group was lower (P < 0.10).

Conclusion

In summary, dietary dandelion supplementation at 500 mg/kg of diet enhanced growth performance of broilers by improving the intestinal barrier function. Dandelion can be supplemented in the diet as an antibiotics alternative to enhance production in poultry industry.

Effects of dietary dandelion extract on the growth performance, serum biochemical parameters, liver histology, and immune and apoptosis-related genes expression of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀) at different feeding period

The study explored on the effects of dietary 0.4% dandelion extract on the growth performance, serum biochemical parameters, liver histology and the expression levels of immune and apoptosis-related genes in the head kidney and spleen of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀) at different feeding period. The results showed that the weight gain rate (WGR) of the hybrid grouper were significantly increased at the second and fourth weeks (P < 0.05), but there was no significant difference in WGR at the eighth week (P > 0.05). Compared with the control group, dietary dandelion extracts supplementation improve lipid metabolism, reduce lipid accumulation in liver and maintain normal liver histology at the second and fourth weeks. At the end of the second week, the relative expression levels of antioxidant related genes (MnSOD, GPX and GR) in the head kidney of hybrid grouper fed with dandelion extract increased significantly; at the end of week 4 and week 8, the relative expression levels of antioxidant related genes other than MnSOD did not change significantly. However, in the spleen of hybrid grouper, the expression of these antioxidant genes showed the opposite trend. At the end of the eighth week, dietary dandelion extract supplementation significantly increased the expression of inflammatory response related genes in head kidney of hybrid grouper, but showed the opposite trend in spleen. In conclusion, the short-term (2 or 4 weeks) application of 0.4% dandelion extract in feed had the effects of growth improvement, liver protection and immune stimulation on hybrid grouper due to its antioxidant and anti-inflammatory activities. The beneficial effect of dandelion extract on hybrid grouper was time-dependent, and its action time on different immune organs of hybrid grouper was not synchronous.

Rational development and evaluation of novel formulations for urinary health

OBJECTIVE

Urinary tract infections (UTI) among women form a substantial part of medical practice and both patients and medical professionals have an interest in non-antibiotic treatments and preventative measures. This research provides preliminary data on a multi-functional composition, DAPAD, which explored several biologic activities of relevance to UTI.

STUDY DESIGN

This formulation included D-mannose, citric acid, three prebiotic compounds, and extracts of dandelion and astragalus. Studies performed employed 4 bacterial strains that have relevance to UTI including E. coli, Proteus mirabilis, Streptococcus agalactiae and Enterococcus faecalis.

RESULTS

Key findings from in vitro studies included: DAPAD at full- and half-strength inhibited growth of all UTI bacteria. Evidence for D-mannose agglutination of E. coli was demonstrated. D-mannose also showed unexpected effects on bacterial membrane integrity with vital staining and modest growth restriction. We did not demonstrate growth inhibition by dandelion or astragalus extracts but the latter showed diminished cytokine elaboration by bladder epithelial cells.

CONCLUSION

DAPAD is a multifunctional composition that may warrant further development as a UTI treatment or preventive if supported by clinical evaluation.

A review: antimicrobial properties of several medicinal plants widely used in Traditional Chinese Medicine

Due to the dramatic increase in the use of antibiotics and growing health threat of bacterial resistance to many commonly used antibiotics, many studies have been directed at developing new and effective antibacterial compounds, among which many new, natural, and effective antibacterial compounds discovered from medicinal plants have drawn great interest and raised new hope for treating the challenges of antibiotic resistance. This review aimed to summarize the most important and widely used medicinal plants that were reported to have antibacterial activities. A general literature search from 2010 to 2020 was conducted using different databases, including Science Direct, Web of Science, and PubMed. According to the literature, three medicinal plants with outstanding antibacterial activities, Taraxacum officinale, Coptis Rhizome, and Scutellaria baicalensis, were screened and reviewed by prioritization. The extraction methods, antibacterial activities of different parts of plants or the plant-derived compounds, spectra of antibacterial activities, and toxicity were described, respectively. However, the antibacterial activities of the extracts or pure compounds as reported in the reviewed literature were mostly based on in vitro assays, and moreover, the deeper antibacterial mechanisms have not been elucidated clearly. Therefore, further studies are required in the fields of purification and identification of the antibacterial compounds, its mechanisms of action, and synergistic effects in combination with other antibacterial drugs, which may be helpful in the development of new antibacterial drugs.

Effect of dandelion root polysaccharide on the pasting, gelatinization, rheology, structural properties and in vitro digestibility of corn starch

The influence of dandelion root polysaccharide (DRP) on the gelatinization properties and in vitro digestibility of corn starch was investigated. Pasting behaviors indicated that the addition of DRP led to an increase of the pasting temperature and a decrease of viscosity. Compared to native corn starch, the swelling power, solubility and content of amylose leaching were reduced as the DRP addition increased. Scanning electron microscopy (SEM) analysis showed that DRP was easily dispersed in the starchy matrix, and a more uniform structure was observed in corn starch/DRP pastes. Fourier transform infrared (FT-IR) and X-ray diffraction (XRD) analyses confirmed that the crystal shape of the corn starch gels was not changed and no new groups were produced with increasing DRP concentration. Moreover, DRP could improve the fluidity of the gelatinized corn starch and reduce its digestibility. These findings provided fundamental information about DRP's application in the whole processing of corn starch.

Delineating the inherent functional descriptors and biofunctionalities of pectic polysaccharides

Pectin is a plant-based heteropolysaccharide macromolecule predominantly found in the cell wall of plants. Pectin is commercially extracted from apple pomace, citrus peels and sugar beet pulp and is widely used in the food industry as a stabilizer, emulsifier, encapsulant, and gelling agent. This review highlights various parameters considered important for describing the inherent properties and biofunctionalities of pectins in food systems. These inherent descriptors include monosaccharide composition, galacturonic acid content, degree of esterification, molecular weight, structural morphology, functional group analysis, and functional properties, such as water and oil holding capacity, emulsification, foaming capacity, foam stability, and viscosity. In this study, we also delineate their potential as a nutraceutical, prebiotic, and carrier for bioactive compounds. The biofunctionalities of pectin as an anticancer, antioxidant, lipid-lowering, and antidiabetic agent are also conceptually elaborated in the current review. The multidimensional characteristics of pectin make it a potential candidate for use in food and biomedical science.

Dandelion extract relaxes mouse airway smooth muscle by blocking VDLCC and NSCC channels

BACKGROUND

Asthma is one of the main intractable diseases recognized by the international medical community. The current widely used bronchodilators for asthma-β2-adrenal receptor agonists-have limited therapeutic effects, necessitating the development of novel antiasthma drugs with increased efficacy and fewer adverse effects. In this study, we investigated the relaxant effects and underlying mechanism of an ethyl acetate extract from dandelion (EAED) on mouse airway smooth muscle.

METHODS

The effects of EAED on agonist-induced precontraction in mouse airway smooth muscle were evaluated with force measurement. Mouse lung slices were used to study the effects of EAED on bronchial smooth muscle. The intracellular Ca2+ concentration was measured using a calcium imaging system. L-type voltage-dependent calcium channel (VDLCC) and non-selective cationic channel (NSCC) currents were measured by patch-clamp. The lung functions of healthy and asthmatic mouse groups were assessed via the forced oscillation technique.

RESULTS

EAED inhibits acetylcholine-induced sustained contractions of whole airway smooth muscle by inhibiting VDLCCs, NSCCs, and some unknown channels, reduces the agonist-induced increase in the cytosolic free Ca2+ concentration in airway smooth muscle cells, blocks VDLCC and NSCC currents, and relieves the respiratory resistance of healthy and asthmatic mice.

CONCLUSIONS

EAED may have potential beneficial effects on mitigating asthma attacks.

A mild and efficient extraction method for polysaccharides from Sinonovacula constricta and study of their structural characteristic and antioxidant activities

The aim of this paper is to develop a mild and efficient extraction method for polysaccharides from Sinonovacula constricta (SCP) using enzyme extraction, and analyze the structural characteristics and antioxidant activities of the two purified polysaccharide fractions (SCP-1 and SCP-2). Firstly, enzyme extraction conditions were optimized, and the conditions were found to be, as follows: enzymolysis time 173.0 min, pH 8.2, enzymolysis temperature 50.0 ℃ and enzyme content 4.0%. Comparison between enzymatic extraction and water extraction was obtained from visual, UV-visible and IR spectrum images. The results clearly indicate that there is no significant difference between them with regard to the composition of the SCP fraction, but the polysaccharide content produced by enzymatic extraction is higher. Then, the physicochemical properties and structural characteristics of SCP-1 and SCP-2 were investigated using FT-TR, UV, GC and HPGPC. The carbohydrate content, sulfuric radicals and uronic acids of the two fractions were detected. Both SCP-1 and SCP-2 were mainly consisted of glucose, but their molecular weights were different. In addition, compared the Fe²⁺ chelating activity, ABTS⁺ radical and superoxide radical scavenging activity, and lipid peroxidation inhibition activity of SCP-1 and SCP-2, it turned out that SCP-2 had stronger antioxidant activity than SCP-1.

The Effect of Diet Supplemented with Dandelion’s (Taraxacum Officinale) Extract on the Productive and Blood Parameters of Common Carp (Cyprinus Carpio L.), Cultivated in the Recirculation System

The aim of the current study was to test the effect of a diet supplemented with dandelion’s (Taraxacum officinale) extract on the productive traits and blood parameters in common carp (Cyprinus carpio L.) cultivated in an recirculation aquaculture system. The carps were cultivated at a stocking density of 7.2 kg/m3 in recirculation aquaculture system. The fish were split into the following two experimental groups: DF (the fish were fed with feed supplemented with dandelion’s extract) and CF (the fish were fed with feed without supplementation). Common carp fed with a diet added with dandelion’s extract at a quantity of 0.8% from daily feed ratio, did not affect the hydrochemical parameters (pH, dissolved oxygen, and electrical conductivity). The carps fed with feed supplemented with dandelion’s extract did not show better productive traits compared with these found for carp from the control variant. The carp from experimental groups had a higher survival rate, final weight, average individual weight gain and specific growth rate (SGR), respectively with 13.2%, 3.94%, 31.5% and 31.3%, compared with the average values of these parameters measured in individuals fed with the control feed, but the differences were not statistically significant (P≥0.05). Supplementation of feed with dandelion’s extract significantly decreased the plasma cholesterol (4.76%) and triglyceride (61.2%) content, promoting hypolipidemic status in fish (P≤0.05).

Comparative In Vitro Evaluation of Antibacterial and Osteogenic Activity of Polysaccharide and Flavonoid Fractions Isolated from the leaves of Saussurea controversa

The osteogenic, cytotoxic, and antibacterial activities of polysaccharide (PS-SC) and flavonoid (F-SC) fractions isolated from the leaves extract of Saussurea controversa were studied in vitro. F-SC consists of the five quercetin glycosides in the ratio 2:8:10:1:4, which were isolated from the leaves extract of S. controversa and have been characterized previously. PS-SC was first isolated from the leaves extract of S. controversa and has been described. PS-SC consists in 30 compounds is characterized by a high degree of heterogeneity with a heterogeneity index of 19.74. The Mw and Mn of PS-SC were 108.6 and 5.5 kDa, respectively. Structural fragments are represented by galactose, arabinose, xylose, glucose, uronic acids, mannose, and rhamnose in a 10.1:3.3:2.2:2.1:1.7:0.9:0.5 molar ratio. F-SC as compared with PS-SC showed in vitro microbicidal (50 g/L) and better bacteriostatic (6.25 g/L versus 25 g/L of PS-SC) effects against the 24-h growth of Staphylococcus aureus strain 209 P and a 21-day absence of cytotoxicity on human adipose-derived multipotent mesenchymal stromal cells (hAMMSCs). Both fractions (PS-SC>F-SC) at doses of 10-50 mg/L stimulated differentiation of hAMMSCs into secreting osteoblasts accompanied by local mineralization of extracellular matrix. These fractions of S. controversa and especially F-SC, might be promising peroral drugs in the complex treatment of bone fractures and for prophylaxis of their infectious complications.

Effects of dietary dandelion extracts on growth performance, liver histology, immune-related gene expression and CCl4 resistance of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀)

The study investigated the effects of dietary supplementation with dandelion extracts (DE) on growth performance, feed utilization, body composition, serum biochemical, liver histology, immune-related gene expression and CCl₄ resistance of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀). A basal diet supplemented with DE at 0% (diet 0%), 0.1% (diet 0.1%), 0.2% (diet 0.2%), 0.4% (diet 0.4%) and 0.8% (diet 0.8%) were fed to hybrid grouper for 8 weeks. The results revealed that dietary DE had not a significant impact on growth performance and feed utilization (P > 0.05), but it could decrease the percent of crude lipids in whole body and increase the percent of crude protein in muscle (P < 0.05). Dietary DE increased the mRNA levels of antioxidant enzymes (catalase, glutathione peroxidase and glutathione reductase) and reduced inflammatory factor in the spleen and head-kidney of fish (P < 0.05), but reduced the expression of the liver antioxidant gene except for glutathione reductase (P < 0.05). Dietary supplementation with 0.2%-0.4% DE could effectively improve liver health. After injection of CCL₄ by 72 h, fish fed Diet0.2% and Diet0.4% showed regular hepatocyte morphology while fish fed Diet 0%, Diet 0.1% and Diet 0.8% showed hepatocyte damage. Higher survival rate and total blood cell count was observed in fish fed 0.1%-0.4% dietary DE (P < 0.05). In conclusion, DE could be used as a functional feed additive to enhance liver function of farmed fish. The best level of it should be between 0.2% and 0.4%.

Ethnobotany of the genus Taraxacum-Phytochemicals and antimicrobial activity

Plants belonging to the genus Taraxacum have been used in traditional healthcare to treat infectious diseases including food-borne infections. This review aims to summarize the available information on Taraxacum spp., focusing on plant cultivation, ethnomedicinal uses, bioactive phytochemicals, and antimicrobial properties. Phytochemicals present in Taraxacum spp. include sesquiterpene lactones, such as taraxacin, mongolicumin B, and taraxinic acid derivatives; triterpenoids, such as taraxasterol, taraxerol, and officinatrione; and phenolic derivatives, such as hydroxycinnamic acids (chlorogenic, chicoric, and caffeoyltartaric acids), coumarins (aesculin and cichoriin), lignans (mongolicumin A), and taraxacosides. Aqueous and organic extracts of different plant parts exhibit promising in vitro antimicrobial activity relevant for controlling fungi and Gram-positive and Gram-negative bacteria. Therefore, this genus represents a potential source of bioactive phytochemicals with broad-spectrum antimicrobial activity. However, so far, preclinical evidence for these activities has not been fully substantiated by clinical studies. Indeed, clinical evidence for the activity of Taraxacum bioactive compounds is still scant, at least for infectious diseases, and there is limited information on oral bioavailability, pharmacological activities, and safety of Taraxacum products in humans, though their traditional uses would suggest that these plants are safe.

Antibacterial activity of PEO nanofibers incorporating polysaccharide from dandelion and its derivative

A water-soluble antibacterial polysaccharide from dandelions (PD) was chemically modified to obtain its carboxymethylated derivative (CPD). The degree of substitution of CPD was 0.455. Fourier transform infrared (FTIR) spectra analysis, zeta potential, particle size and rheological test verified the carboxymethylation of PD, accompanying with the change of physicochemical properties. Moreover, Listeria monocytogenes treated with 10 mg/mL PD and CPD achieved 1.96 and 3.29 log CFU/mL reduction in population, respectively. Subsequently, PD and CPD were incorporated into polyethylene oxide (PEO) nanofiber matrix to fabricate antimicrobial nanofibers. The prepared nanofibers were characterized by scanning electron microscope, atomic force microscope and FTIR. Finally, both PD/PEO and CPD/PEO nanofibers exhibited favourable antibacterial effect on L. monocytogenes, with an improved antibacterial activity of CPD/PEO nanofibers than PD/PEO nanofibers. In conclusion, this study demonstrated PD and CPD could be applied to the fabrication of antibacterial food packaging.

Effects of dietary dandelion extract on intestinal morphology, antioxidant status, immune function and physical barrier function of juvenile golden pompano Trachinotus ovatus

Intestinal morphology, antioxidant status, immune function and tight junction proteins mRNA expression were examined in golden pompano (Trachinotus ovatus) that fed respectively six diets containing dandelion extracts (DE) at 0, 0.5, 1, 2, 4 and 10 g kg^-1 after 8 weeks feeding. The study indicated that dietary DE significantly improved intestinal antioxidant abilities by increasing SOD, CAT, T-AOC activities and up-regulating intestinal cat, gpx mRNA levels, but by decreasing MDA content and down-regulating intestinal keap1 mRNA levels in golden pompano. Meanwhile, dietary DE improved intestinal morphology, suggesting that enhances intestinal digestion and absorption, by increasing muscle thickness, villus length, villus width and villus number in the foregut and hindgut; as well as villus number, villus width and muscle thickness in the midgut (P < .05). Dietary DE enhanced intestinal barrier function by increasing intestinal zo-1 and occludin mRNA levels, but by decreasing the mRNA levels of claudin-12 and claudin-15. Furthermore, dietary DE improved intestinal immunity via increasing goblet cells numbers and regulating expression of immune-related genes. In conclusion, dietary DE supplementation promoted intestine health by improving intestine morphology, immunity, antioxidant abilities and intestinal barrier in golden pompano.

Purification, Preliminary Characterization and Hepatoprotective Effects of Polysaccharides from Dandelion Root

In this study, purification, preliminary characterization and hepatoprotective effects of water-soluble polysaccharides from dandelion root (DRP) were investigated. Two polysaccharides, DRP1 and DRP2, were isolated from DRP. The two polysaccharides were α-type polysaccharides and didn't contain protein. DRP1, with a molecular weight of 5695 Da, was composed of glucose, galactose and arabinose, whereas DRP2, with molecular weight of 8882 Da, was composed of rhamnose, galacturonic acid, glucose, galactose and arabinose. The backbone of DRP1 was mainly composed of (1→6)-linked-α-d-Glc and (1→3,4)-linked-α-d-Glc. DRP2 was mainly composed of (1→)-linked-α-d-Ara and (1→)-linked-α-d-Glc. A proof-of-concept study was performed to assess the therapeutic potential of DRP1 and DRP2 in a mouse model that mimics acetaminophen (APAP) -induced liver injury (AILI) in humans. The present study shows DRP1 and DRP2 could protect the liver from APAP-induced hepatic injury by activating the Nrf2-Keap1 pathway. These conclusions demonstrate that the DRP1 and DRP2 might be suitable as functional foods and natural drugs in preventing APAP-induced liver injury.

Effects of dietary dandelion extracts on growth performance, body composition, plasma biochemical parameters, immune responses and disease resistance of juvenile golden pompano Trachinotus ovatus

The present study was conducted to investigate the effects of dietary dandelion extracts (DE) supplementation on growth performance, feed utilization, body composition, plasma biochemical indices, immune responses, hepatic antioxidant abilities, and resistance to the pathogen Vibrio harveyi in Trachinotus ovatus. A basal diet supplemented with DE at 0, 0.50, 1.00, 2.00, 4.00 and 10.00 g kg^-1 were fed to golden pompano for 8 weeks. The study indicated that dietary supplementation with DE could significantly improve final body weight (FBW), weight gain rate (WGR), specific growth rate (SGR), feed efficiency ratio (FER), feed intake (FI), protein efficiency ratio (PER) and protein deposit rate (PDR) (P < 0.05). The highest FBW, WGR, SGR, FI and PDR were observed in fish fed 1.00 g kg^-1 dietary DE (P < 0.05). The highest FER and PER were recorded at 0.50 g kg^-1 dietary DE (P < 0.05). Condition factor, viscerosomatic index, hepatosomatic index and survival were not significantly different among all groups. Fish fed 1.00 g kg^-1 dietary DE showed significant increase in plasma total protein, complement 4 content and alkaline phosphatase, lysozyme, glutathione reductase (GSR) activity, but significant decrease in triglyceride, low density lipoprotein cholesterol, malondialdehyde (MDA) content and aspartate aminotransferase activities compared to the control group (P < 0.05). Hepatic antioxidant enzymes (SOD, T-AOC, CAT, GSH-Px, GSR) significantly increased whereas MDA content significantly decreased in fish fed 1.00 g kg^-1 DE supplement (P < 0.05). After challenge with Vibrio harveyi, significant higher post-challenge survival was observed in fish fed DE supplement (P < 0.05). These results indicated that golden pompano fed a diet supplemented with DE (especially at 1.00 g kg^-1 of fed supplement) could significantly promote its growth performance, feed utilization, body protein deposit, immune ability, hepatic and plasma antioxidative enzyme activities and improve its resistance to infection by Vibrio harveyi.

Optimization of cellulase-assisted extraction process and antioxidant activities of polysaccharides from Tricholoma mongolicum Imai

BACKGROUND

Tricholoma mongolicum Imai is a well-known edible and medicinal mushroom which in recent years has attracted increasing attention because of its bioactivities. In this study, water-soluble polysaccharides were extracted from T. mongolicum Imai by cellulase-assisted extraction and their antioxidant activities were investigated.

RESULTS

In order to improve the yield of polysaccharides, four variables, cellulase amount (X1 ), pH (X2 ), temperature (X3 ) and extraction time (X4 ), were investigated with a Box-Behnken design. The optimal conditions were predicted to be cellulase amount of 20 g kg(-1) , pH of 4.0, temperature of 50 °C and extraction time of 127 min, with a predicted polysaccharide yield of 190.1 g kg(-1) . The actual yield of polysaccharides under these conditions was 189.6 g kg(-1) , which matched the predicted value well. The crude polysaccharides were purified to obtain four fractions, and characterization of each was carried out. In addition, antioxidant properties of four polysaccharides assessed by 1,1-diphenyl-2-picryldydrazyl (DPPH) and hydroxyl radical-scavenging assays indicated that polysaccharides from T. mongolicum Imai (TMIPs) possessed antioxidant activity in a dose-dependent manner.

CONCLUSION

TMIPs show moderate antioxidant activities in vitro. Therefore it is suggested that TMIPs are potential natural antioxidants for use in functional foods. © 2016 Society of Chemical Industry.