[Applications of ion chromatography for the analysis of Chinese herbal medicine components].

Ion chromatography (IC) is a novel high performance liquid chromatographic technique that is suitable for the separation and analysis of ionic substances in different matrix samples. Since 1975, it has been widely used in many fields, such as the environment, energy, food, and medicine. IC compensates for the separation limitations of traditional gas chromatography and high performance liquid chromatography and can realize the qualitative analysis and quantitative detection of strongly polar components. This chromatographic technique features not only simple operations but also rapid analysis. The sensors used in IC are characterized by high sensitivity and selectivity, and the technique can simultaneously separate and determine multiple components. Several advances in IC instrumentation and chromatographic theories have been developed in recent years. IC can analyze various types of samples, including ions, sugars, amino acids, and organic acids (bases). Chinese herbal medicines are typically characterized by highly complex chemical compositions and may contain carbohydrates, proteins, alkaloids, and other active components. They also contain toxic residues such as sulfur dioxide, which may be produced during the processing of medicinal materials. Therefore, the analysis and elucidation of the precise chemical constituents of Chinese herbal medicines present key problems that must be resolved in modern Chinese herbal medicine research. In this context, IC has become an important method for analyzing and identifying the complex components of Chinese herbal medicines because this method is suitable for detecting a single active ingredients among complex components. This paper introduces the different types and principles of IC as well as research progress in this technique. As the applications of IC-based methods in pharmaceutical science, cell biology, and microbiology increase, further development is necessary to expand the applications of this technique. The development of innovative techniques has enabled IC technologies to achieve higher analytical sensitivity, better selectivity, and wider application. The components of Chinese herbal medicines can be divided into endogenous and exogenous components according to their source: endogenous components include glycosides, amino acids, and organic acids, while exogenous components include toxic residues such as sulfur dioxide. Next, the applications of IC to the complex components of Chinese herbal medicines in recent decades are summarized. The most commonly used IC technologies and methods include ion exchange chromatography and conductivity detection. The advantages of IC for the analysis of alkaloids have been demonstrated. This method exhibits better characteristics than traditional analytical methods. However, the applications of IC for the speciation analysis of inorganic anions are limited. Moreover, few reports on the direct application of the technique for the determination of the main active substances in Chinese herbal medicines, including flavonoids, phenylpropanoids, and steroids, have been reported. Finally, this paper reviews new IC technologies and their application progress in Chinese herbal medicine, focusing on their prospects for the effective separation and analysis of complex components. In particular, we discuss the available sample (on-line) pretreatment technologies and explore possible technologies for the selective and efficient enrichment and separation of different components. Next, we assess innovative research on solid-phase materials that can improve the separation effect and analytical sensitivity of IC. We also describe the features of multidimensional chromatography, which combines the advantages of various chromatographic techniques. This review provides a theoretical reference for the further development of IC technology for the analysis of the complex chemical components of Chinese herbal medicines.

Salidroside protects pulmonary artery endothelial cells against hypoxia-induced apoptosis via the AhR/NF-κB and Nrf2/HO-1 pathways.

BACKGROUND: The apoptosis of pulmonary artery endothelial cells (PAECs) is an important factor contributing to the development of pulmonary hypertension (PH), a serious cardio-pulmonary vascular disorder. Salidroside (SAL) is a bioactive compound derived from an herb Rhodiola, but the potential protective effects of SAL on PAECs and the underlying mechanisms remain elusive. PURPOSE: The objective of this study was to determine the role of SAL in the hypoxia-induced apoptosis of PAECs and to dissect the underlying mechanisms. STUDY DESIGN: Male Sprague-Dawley (SD) rats were subjected to hypoxia (10% O2) for 4 weeks to establish a model of PH. Rats were intraperitoneally injected daily with SAL (2, 8, and 32 mg/kg/d) or vehicle. To define the molecular mechanisms of SAL in PAECs, an in vitro model of hypoxic cell injury was also generated by exposed PAECs to 1% O2 for 48 h. METHODS: Various techniques including hematoxylin and eosin (HE) staining, immunofluorescence, flow cytometry, CCK-8, Western blot, qPCR, molecular docking, and surface plasmon resonance (SPR) were used to determine the role of SAL in rats and in PAECs in vitro. RESULTS: Hypoxia stimulation increases AhR nuclear translocation and activates the NF-κB signaling pathway, as evidenced by upregulated expression of CYP1A1, CYP1B1, IL-1ß, and IL-6, resulting in oxidative stress and inflammatory response and ultimately apoptosis of PAECs. SAL inhibited the activation of AhR and NF-κB, while promoted the nuclear translocation of Nrf2 and increased the expression of its downstream antioxidant proteins HO-1 and NQO1 in PAECs, ameliorating the hypoxia-induced oxidative stress in PAECs. Furthermore, SAL lowered right ventricular systolic pressure, and decreased pulmonary vascular remodeling and right ventricular hypertrophy in hypoxia-exposed rats. CONCLUSIONS: SAL may attenuate the apoptosis of PAECs by suppressing NF-κB and activating Nrf2/HO-1 pathways, thereby delaying the progressive pathology of PH.

A novel bHLH gene responsive to low nitrogen positively regulates the biosynthesis of medicinal tropane alkaloids in Atropa belladonna.

Medicinal tropane alkaloids (TAs), including hyoscyamine, anisodamine and scopolamine, are essential anticholinergic drugs specifically produced in several solanaceous plants. Atropa belladonna is one of the most important medicinal plants that produces TAs. Therefore, it is necessary to cultivate new A. belladonna germplasm with the high content of TAs. Here, we found that the levels of TAs were elevated under low nitrogen (LN) condition, and identified a LN-responsive bHLH transcription factor (TF) of A. belladonna (named LNIR) regulating the biosynthesis of TAs. The expression level of LNIR was highest in secondary roots where TAs are synthesized specifically, and was significantly induced by LN. Further research revealed that LNIR directly activated the transcription of hyoscyamine 6ß-hydroxylase gene (H6H) by binding to its promoter, which converts hyoscyamine into anisodamine and subsequently epoxidizes anisodamine to form scopolamine. Overexpression of LNIR upregulated the expression levels of TA biosynthesis genes and consequently led to the increased production of TAs. In summary, we functionally identified a LN-responsive bHLH gene that facilitated the development of A. belladonna with high-yield TAs under the decreased usage of nitrogen fertilizer.

Dracotangusions A and B, two new sesquiterpenes from Dracocephalum tanguticum Maxim. with anti-inflammatory activity.

Two new guaiane sesquiterpenoids were isolated from the dried aerial parts of Dracocephalum tanguticum Maxim., named as dracotangusions A (1) and B (2), together with four known sesquiterpenoids, which were identified as Curcumenone (3), (4Z,7Z,9Z)-11-Hydroxy-4,7,9-germacratriene-1,6-dione (4), Kobusone (5), and (1S,10S), (4S, 5S)-(+)-germacrone-1(10)-4-diepoxide (6). The structures of isolates were determined by UV, IR, HR-ESI-MS, and NMR analysis. What is noteworthy is that four known sesquiterpenoids were isolated for the first time from the genus of Dracocephalum L. All compounds inhibited the extremely significant difference (p < 0.01) in anti-inflammatory activity, suggesting that these compounds may be promising candidates as an anti-inflammatory agent.

Herpetrione, a New Type of PPARα Ligand as a Therapeutic Strategy Against Nonalcoholic Steatohepatitis.

Non-alcoholic fatty liver disease, especially nonalcoholic steatohepatitis (NASH), is a leading cause of cirrhosis and liver cancer worldwide; nevertheless, there are no Food and Drug Administration-approved drugs for treating NASH until now. Peroxisome proliferator-activated receptor alpha (PPARα) is an interesting therapeutic target for treating metabolic disorders in the clinic, including NASH. Herpetrione, a natural lignan compound isolated from Tibetan medicine Herpetospermum caudigerum, exerts various hepatoprotective effects, but its efficacy and molecular mechanism in treating NASH have not yet been elucidated. Here, we discovered that herpetrione lessened lipid accumulation and inflammation in hepatocytes stimulated with oleic acid and lipopolysaccharide, and effectively alleviated NASH caused by a high-fat diet or methionine-choline-deficient diet by regulating glucolipid metabolism, insulin resistance, and inflammation. Mechanistically, RNA-sequencing analyses further showed that herpetrione activated PPAR signaling, which was validated by protein expression. Furthermore, the analysis of molecular interactions illustrated that herpetrione bound directly to the PPARα protein, with binding sites extending to the Arm III domain. PPARα deficiency also abrogated the protective effects of herpetrione against NASH, suggesting that herpetrione protects against hepatic steatosis and inflammation by activation of PPARα signaling, thereby alleviating NASH. Our findings shed light on the efficacy of a natural product for treating NASH, as well as the broader prospects for NASH treatment by targeting PPARα.

Endophytic bacterial community structure and diversity of the medicinal plant Mirabilis himalaica from different locations.

Endophytic bacteria play important roles in medicinal plant growth, abiotic stress, and metabolism. Mirabilis himalaica (Edgew.) Heimerl is known for its medicinal value as Tibetan traditional plant; however, little is known about the endophytic bacteria associated with this plant in different geographic conditions and vegetal tissues. To compare the endophytic bacterial community associated with this plant in different geographic conditions and vegetal tissues, we collected the leaves, stems, and roots of M. himalaica from five locations, Nongmu college (NM), Gongbujiangda (GB), Zhanang County (ZL), Lang County (LX), and Sangri County (SR), and sequenced the 16S rRNA V5-V7 region with the Illumina sequencing method. A total of 522,450 high-quality sequences and 4970 operational taxonomic units (OTUs) were obtained. The different tissues from different locations harbored unique bacterial assemblages. Proteobacteria and Actinobacteria were the dominant phyla in all the samples, while the dominant genera changed based on the different tissues. The endophytic bacterial structures in the leaf and stem tissues were different compared to root tissues. Redundancy analysis (RDA) showed that the endophytic bacterial community was significantly correlated with pH, available phosphorus (AP), total phosphorus (TP), total nitrogen (TN), and soil organic matter (SOM). These findings suggested that the geographic conditions, climate type, ecosystem type, and tissues determined the endophytic bacterial composition and relative abundances. This conclusion could facilitate an understanding of the relationship and ecological function of the endophytic bacteria associated with M. himalaica and provide valuable information for artificial planting of M. himalaica and identifying and applying functional endophytic bacteria.

Insights into the mechanism underlying UV-B induced flavonoid metabolism in callus of a Tibetan medicinal plant Mirabilis himalaica.

Mirabilis himalaica is an important Tibetan medicinal plant in China. However, it has become a rare and class I endangered Tibetan medicine plant. Therefore, the use of callus to propagate germplasm resources is of great significance. We found that the flavonoid content of M. himalaica callus increased continuously with the extension of UV-B treatment. Multi-omics profiles were used to reveal the co-expression patterns of gene networks of flavonoid metabolism in M. himalaica callus during UV-B radiation. Results showed that five medicinal metabolics, including geranin, eriodictyol, astragalin, isoquercetin, pyrotechnic acid, and one anthocyanin malvide-3-O-glucoside were identified. The transcriptome data were divided into 46 modules according to the expression pattern by WGCNA (weighted gene co-expression network analysis), of which the module Turquoise had the strongest correlation with six target metabolites. We found that seven structural genes and twenty-five transcription factors were related to the metabolism of flavonoid synthesis, among which the structural genes CHI, C4H and UGT79B6 had strong co-expression relationships with the 6 target metabolites. WRKY42, WRKY7, bHLH128 and other transcription factors had strong co-expression relationships with multiple structural genes. Consequently, these findings suggest callus grown under UV-B treatment could be an effective alternative medical resource of M. himalaica, which is valuable for conservation and usage of this wild and endangered plant.

Oxybaphus himalaicus Mitigates Lipopolysaccharide-Induced Acute Kidney Injury by Inhibiting TLR4/MD2 Complex Formation.

Acute kidney injury (AKI) is described as the abrupt decrease in kidney function always accompanied by inflammation. The roots of Oxybaphus himalaicus Edgew. have long been used in Tibetan folk medicine for the treatment of nephritis. Nevertheless, modern pharmacological studies, especially about the underlying mechanism of O. himalaicus medications, are still lacking. Here, in lipopolysaccharide (LPS)-induced RAW264.7 macrophages, the O. himalaicus extract (OE) showed significant anti-inflammatory activity with the dose dependently reducing the LPS-stimulated release of nitric oxide and the mRNA level and protein expression of inflammatory cytokines and reversed the activation of nuclear factor kappa B (NF-κB). Co-immunoprecipitation assay indicated that OE inhibited Toll-like receptor 4/myeloid differentiation factor 2 (TLR4/MD2) complex formation and further suppressed both myeloid differentiation factor 88 (MyD88)-dependent and TIR-domain-containing adapter-inducing interferon-ß (TRIF)-dependent cascades activation. In addition, OE could restrain NADPH oxidase 2 (NOX2) endocytosis by blocking TLR4/MD2 complex formation to prevent reactive oxygen species production. In LPS-induced AKI mice, OE treatment mitigated renal injury and inflammatory infiltration by inhibiting TLR4/MD2 complex formation. UPLC-MS/MS analysis tentatively identified 41 components in OE. Our results indicated that OE presented significant anti-inflammatory activity by inhibiting TLR4/MD2 complex formation, which alleviated LPS-induced AKI in mice.

Comparative analyses of chloroplast genomes from Six Rhodiola species: variable DNA markers identification and phylogenetic relationships within the genus.

BACKGROUND: As a valuable medicinal plant, Rhodiola has a very long history of folk medicine used as an important adaptogen, tonic, and hemostatic. However, our knowledge of the chloroplast genome level of Rhodiola is limited. This drawback has limited studies on the identification, evolution, genetic diversity and other relevant studies on Rhodiola. RESULTS: Six Rhodiola complete chloroplast genomes were determined and compared to another Rhodiola cp genome at the genome scale. The results revealed a cp genome with a typical quadripartite and circular structure that ranged in size from 150,771 to 151,891 base pairs. High similarity of genome organization, gene number, gene order, and GC content were found among the chloroplast genomes of Rhodiola. 186 (R. wallichiana) to 200 (R. gelida) SSRs and 144 pairs of repeats were detected in the 6 Rhodiola cp genomes. Thirteen mutational hotspots for genome divergence were determined and could be used as candidate markers for phylogenetic analyses and Rhodiola species identification. The phylogenetic relationships inferred by members of Rhodiola cluster into two clades: dioecious and hermaphrodite. Our findings are helpful for understanding Rhodiola's taxonomic, phylogenetic, and evolutionary relationships. CONCLUSIONS: Comparative analysis of chloroplast genomes of Rhodiola facilitates medicinal resource conservation, phylogenetic reconstruction and biogeographical research of Rhodiola.

Transcriptome and Metabolome Analyses of Codonopsis convolvulacea Kurz Tuber, Stem, and Leaf Reveal the Presence of Important Metabolites and Key Pathways Controlling Their Biosynthesis.

Codonopsis convolvulacea Kurz. var. vinciflora (Kom.) L.T. Shen is a member of Campanulaceae, which is used in traditional Chinese medicine. However, apart from a few Codonopsis species, no detailed knowledge is available on the metabolite composition and respective transcriptome signatures. We performed a combined transcriptome and metabolome analysis of the tuber, stem, and leaf of C. convolvulacea and found 1,144 metabolites and 231,840 unigenes in three experimental groups. The analysis revealed considerable variations in the three tissues. Tubers were rich in amino acids and derivatives, flavonoids, and organic acids, whereas the stems and leaves were rich in alkaloids and flavonoids, respectively. Transcriptome sequencing revealed candidate genes being involved in flavonoid, tryptophan, and alkaloid biosyntheses. In particular, we indicated that the variation in the isoflavone content is linked to the expressions of CHI, CYP73A, C3'H, F3H, CYP75B1, anthocyanidin synthase, and FLS. In a similar way, the levels of indole, L-tyrosine, and tryptamine were also consistent with the expressions of TDC/DDCs in the respective tissues. In addition, the expression levels of ASP5, ARO8, GOT, and AOC3 indicated that L-tryptophan is being converted to downstream metabolites. Overall, our datasets present a useful resource for future research on the uses of this medicinal plant and put forward many research questions.

Biotechnological Approaches on Engineering Medicinal Tropane Alkaloid Production in Plants.

Hyoscyamine and scopolamine, belonging to medicinal tropane alkaloids (MTAs), are potent anticholinergic drugs. Their industrial production relies on medicinal plants, but the levels of the two alkaloids are very low in planta. Engineering the MTA's production is an everlasting hot topic for pharmaceutical industry. With understanding the MTA's biosynthesis, biotechnological approaches are established to produce hyoscyamine and scopolamine in an efficient manner. Great advances have been obtained in engineering MTA's production in planta. In this review, we summarize the advances on the biosynthesis of MTAs and engineering the MTA's production in hairy root cultures, as well in plants. The problems and perspectives on engineering the MTA's production are also discussed.

Selection and Validation of Reference Genes for RT-qPCR Analysis in Tibetan Medicinal Plant Saussurea Laniceps Callus under Abiotic Stresses and Hormone Treatments.

Real-time quantitative PCR (RT-qPCR) is an important technique for studying gene expression analysis, but accurate and reliable results depend on the use of a stable reference gene. This study proposes to test the expression stability of candidate reference genes in the callus of Saussurea laniceps, a unique Tibetan medicinal plant. Based on the S. laniceps callus transcriptome, eleven candidate reference genes, including TUA2, TUB3, TUB8, TIF3B1, TIF3H1, ELF5A, PP2AA2, UEV1D, UBL5, UBC36, and SKIP1), were validated for RT-qPCR normalization in the callus under abiotic stress (salt, cold, and UV) and hormone treatments (abscisic acid, MeJA, and salicylic acid). The stability of the candidate genes was evaluated in all the samples of S. laniceps. Comprehensive analysis of all samples showed that the best reference genes were UBC36 and UBL5. ELF5A and TIF3B1 were ranked as the most stable genes in the sample sets under abiotic stress. For hormone stimulation, UBC36 and TIF3H1 genes had the best stability. This study provides useful guidelines and a starting point for reference gene selection for expression analysis using RT-qPCR techniques in S. laniceps.

Sequencing the organelle genomes of Bougainvillea spectabilis and Mirabilis jalapa (Nyctaginaceae).

OBJECTIVES: Mirabilis jalapa L. and Bougainvillea spectabilis are two Mirabilis species known for their ornamental and pharmaceutical values. The organelle genomes are highly conserved with a rapid evolution rate making them suitable for evolutionary studies. Therefore, mitochondrial and chloroplast genomes of B. spectabilis and M. jalapa were sequenced to understand their evolutionary relationship with other angiosperms. DATA DESCRIPTION: Here, we report the complete mitochondrial genomes of B. spectabilis and M. jalapa (343,746 bp and 267,334 bp, respectively) and chloroplast genomes of B. spectabilis (154,520 bp) and M. jalapa (154,532 bp) obtained from Illumina NovaSeq. The mitochondrial genomes of B. spectabilis and M. jalapa consisted of 70 and 72 genes, respectively. Likewise, the chloroplast genomes of B. spectabilis and M. jalapa contained 131 and 132 genes, respectively. The generated genomic data will be useful for molecular characterization and evolutionary studies.

Lignans from the seeds of Herpetospermum pedunculosum and their farnesoid X receptor-activating effect.

The seeds of Herpetospermum pedunculosum (Ser.) C.B. Clarke, a well-known Tibetan medicine in China, are rich in kinds of bioactive lignans. In this phytochemical investigation on H. pedunculosum, sixteen undescribed lignans, named as herpedulins A - P together with 24 known ones were isolated from the ethyl acetate extract of its seeds. Their structures including the absolute configurations were determined by HR MS, 1D and 2D NMR experiments, and comparison of their experimental ECD spectra with calculated ones or literature data. High content screening experiments revealed that 9 compounds could promote the expression of farnesoid X receptor in guggulsterone-induced human normal liver cells L02 cells significantly. Further molecular docking results demonstrated that herpedulin E, J and K exhibited best docking scores (9.70, 9.28 and 10.31, respectively). Hydrogen bonding and hydrophobic interactions might contribute to the main interaction of active compounds with FXR.

The complete chloroplast genome of Saussurea medusa maxim. (Asteraceae), an alpine Tibetan herb.

Saussurea medusa is an important traditional Tibetan medicinal plant in China. In this study, we assembled the complete chloroplast (cp) genome of S. medusa. The complete S. medusa chloroplast genome is a circular molecular structure of 152,257 bp in length with coding GC 37.93%, consisting of two inverted repeats (25,204 bp) separated by a large single-copy region (83,334 bp) and a small single-copy region (18,515 bp). The complete chloroplast genome of S. medusa contained 130 genes, including 87 protein-coding genes, 35 tRNA genes, and eight rRNA genes. Phylogenetic analysis shows that S. medusa is most closely related to Saussurea inversa and Saussurea pseudoleucoma. The complete chloroplast genome sequence of S. medusa facilitates the phylogenetic studies of Asteraceae.

[One new coumarin from seeds of Herpetospermum pedunculosum].

This paper aims to investigate the chemical constituents of the seeds of Herpetospermum pedunculosum. One new coumarin and two known lignans were isolated from the ethanolic extract of the seeds of H. pedunculosum with thin layer chromatography(TLC), silica gel column chromatography, Sephedax LH-20 chromatography, Semi-preparative high performance liquid chromatography and recrystallization, etc. Their structures were elucidated as herpetolide H(1), phyllanglaucin B(2), and buddlenol E(3) by analysis of their physicochemical properties and spectral data. Among them, compound 1 was a new compound, and compounds 2 and 3 were isolated from this genus for the first time. In vitro anti-inflammatory activity test showed that herpetolide H had certain NO inhibitory activity for LPS-induced RAW 264.7 cells, with its IC_(50) value of(46.57±3.28) µmol·L~(-1).

Pterocephin A, a novel Triterpenoid Saponin from Pterocephalus hookeri induced liver injury by activation of necroptosis.

BACKGROUND: Pterocephalus hookeri (C. B. Clarke) Höeck, a Tibetan medicine widely used for treatment of rheumatoid arthritis, was recorded in Chinese Pharmacopoeia (2020 version) with slight toxicity. The liver injury was observed in mice with administration of n-butanol extract (BUE) in our previously study. However, the toxic components and the mechanism were still unrevealed. PURPOSE: The present study was aimed to isolate and structural elucidate of the toxic compound pterocephin A (PA), as well as evaluate its liver toxicity and investigate its mechanism. METHODS: PA was isolated from the BUE of P. hookeri. Its structure was determined by analysis of HRMS, NMR and ECD data. L-02 cellular viability, LDH, ALT, AST, ROS, intracellular Ca2+ and the fluidity of cell membrane were assessed by multifunctional microplate reader. The PI staining, cell membrane permeability assessment, and mitochondrial fluorescence staining analysis were determined through the fluorescence microscope. Liver samples for mice were assessed by pathological and immunohistochemistry analysis. Expression levels of indicated proteins were measured by western blotting assays. RESULTS: PA was determined as a previously undescribed oleanolane-type triterpenoid saponin. In vitro study revealed PA significantly induced hepatotoxicity by inhibition of L-02 cell growth, abnormally elevation of ALT and AST. Mechanically, PA induced the damage of cell membrane, fragmentation of mitochondria, and subsequently increase of intracellular Ca2+ and ROS levels, which trigged by necroptosis with the activation of RIP1 and NF-κB signaling pathways. In vivo study confirmed PA could induce liver injury in mice with observation of the body weight loss, increasing of serum ALT and AST, and the histopathological changes in liver tissues. CONCLUSION: Our present study indicated that PA was an undescribed toxic constituent in P. hookeri to induce liver injury in mice by activation of necroptosis and inflammation. And the findings are of great significance for the clinical use safely of this herb.

Ptehoosines A and B: Two new sesamin-type sesquilignans with antiangiogenic activity from Pterocephalus hookeri (C.B. Clarke) Höeck.

Two undescribed sesamin-type sesquilignans ptehoosines A (1) and B (2), together with 4 known lignans (3-6), were isolated from Pterocephalus hookeri (C.B. Clarke) Höeck which was widely used as traditional Tibetan medicine for treatment of rheumatoid arthritis. Their structures were determined by HR-ESI-MS, NMR analysis and CD experiment. The in vitro antiangiogenic effect of all isolated compounds against human umbilical vein endothelial cells (HUVECs) were evaluated by CCK-8 assay. Among them, compound 1 exhibited significant proliferative inhibition on HUVECs with IC50 value of 32.82 ± 0.99 µM. Further in vitro study indicated 1 could arrest cell cycle at G0/G1 phase and reduce the migration of HUVECs. In vivo experiment exhibited 1 could inhibit tail vessels plexus in zebrafish. The above finding suggested that 1 was a promising lead compound against RA by inhibiting of angiogenesis.

Structural properties and in vitro and in vivo immunomodulatory activity of an arabinofuranan from the fruits of Akebia quinata.

In our continuous searching for natural active polysaccharides with immunomodulatory activity, an arabinofuranan (AQP70-3) was isolated and purified from the fruits of Akebia quinata (Houtt.) Decne. by using ion-exchange chromatography and gel permeation chromatography for the first time. AQP70-3 contained both α-l-Araf and ß-l-Araf, and the absolute molecular weight was 1.06 × 104 g/mol. The backbone of AQP70-3 comprised →5)-α-l-Araf-(1→, →3,5)-α-l-Araf-(1→, and →2,5)-α-l-Araf-(1→, with branches of →1)-ß-l-Arafand →3)-α-l-Araf-(1→ residues. Biological assay suggested that AQP70-3 can stimulate phagocytic activity and promote the levels of nitric oxide (NO), interleukin (IL)-6, IL-1ß, and tumor necrosis factor-α (TNF-α) of RAW264.7 cells. Furthermore, AQP70-3 was found to increase the production of reactive oxygen species (ROS) and NO in zebrafish embryo model.

Structural elucidation of an immunological arabinan from the rhizomes of Ligusticum chuanxiong, a traditional Chinese medicine.

In the present study, an immunological arabinan, LCP70-2A, was isolated from Ligusticum chuanxiong for the first time. The absolute molecular weight of LCP70-2A was determined to be 6.46 × 104 g/mol using the HPSEC-MALLS-RID method. The absolute configuration of arabinose in LCP70-2A was determined to be L-configuration. Physicochemical characterization revealed that LCP70-2A was a homogeneous polysaccharide and had a backbone of (1 â†’ 5)-linked α-L-Araf with terminal α-L-arabinose residues at position O-2 and O-3. Molecular conformation analysis showed that LCP70-2A was a branching polysaccharide with a compact coil chain conformation in 0.1 M NaCl solution. In addition, in vitro cell assays showed that LCP70-2A can activate macrophages by enhancing the phagocytosis and potentiating the secretion of immunoregulatory factors including NO, TNF-α, IL-6, and IL-1ß. Furthermore, LCP70-2A was proved to promote the production of ROS and NO using the zebrafish model, suggesting that LCP70-2A can be further developed as a candidate supplement for immunological enhancement.