Progress in Identification of UDP-Glycosyltransferases for Ginsenoside Biosynthesis.

Ginsenosides, the primary pharmacologically active constituents of the Panax genus, have demonstrated a variety of medicinal properties, including anticardiovascular disease, cytotoxic, antiaging, and antidiabetes effects. However, the low concentration of ginsenosides in plants and the challenges associated with their extraction impede the advancement and application of ginsenosides. Heterologous biosynthesis represents a promising strategy for the targeted production of these natural active compounds. As representative triterpenoids, the biosynthetic pathway of the aglycone skeletons of ginsenosides has been successfully decoded. While the sugar moiety is vital for the structural diversity and pharmacological activity of ginsenosides, the mining of uridine diphosphate-dependent glycosyltransferases (UGTs) involved in ginsenoside biosynthesis has attracted a lot of attention and made great progress in recent years. In this paper, we summarize the identification and functional study of UGTs responsible for ginsenoside synthesis in both plants, such as Panax ginseng and Gynostemma pentaphyllum, and microorganisms including Bacillus subtilis and Saccharomyces cerevisiae. The UGT-related microbial cell factories for large-scale ginsenoside production are also mentioned. Additionally, we delve into strategies for UGT mining, particularly potential rapid screening or identification methods, providing insights and prospects. This review provides insights into the study of other unknown glycosyltransferases as candidate genetic elements for the heterologous biosynthesis of rare ginsenosides.

Hepatic metabolomics combined with network pharmacology to reveal the correlation between the anti-depression effect and nourishing blood effect of Angelicae Sinensis Radix.

Angelicae Sinensis Radix (AS) is reproted to exert anti-depression effect (ADE) and nourishing blood effect (NBE) in a rat model of depression. The correlation between the two therapeutic effects and its underlying mechanisms deserves further study. The current study is designed to explore the underlying mechanisms of correlation between the ADE and NBE of AS based on hepatic metabonomics, network pharmacology and molecular docking. According to metabolomics analysis, 30 metabolites involved in 11 metabolic pathways were identified as the potential metabolites for depression. Furthermore, principal component analysis and correlation analysis showed that glutathione, sphinganine, and ornithine were related to pharmacodynamics indicators including behavioral indicators and hematological indicators, indicating that metabolic pathways such as sphingolipid metabolism were involved in the ADE and NBE of AS. Then, a target-pathway network of depression and blood deficiency syndrome was constructed by network pharmacology analysis, where a total of 107 pathways were collected. Moreover, 37 active components obtained from Ultra Performance Liquid Chromatography-Triple-Time of Flight Mass Spectrometer (UPLC-Triple-TOF/MS) in AS extract that passed the filtering criteria were used for network pharmacology, where 46 targets were associated with the ADE and NBE of AS. Pathway enrichment analysis further indicated the involvement of sphingolipid metabolism in the ADE and NBE of AS. Molecular docking analysis indciated that E-ligustilide in AS extract exhibited strong binding activity with target proteins (PIK3CA and PIK3CD) in sphingolipid metabolism. Further analysis by Western blot verified that AS regulated the expression of PIK3CA and PIK3CD on sphingolipid metabolism. Our results demonstrated that sphingolipid metabolic pathway was the core mechanism of the correlation between the ADE and NBE of AS.

Mechanism of Jindanjiangan Capsule in the treatment of hepatic fibrosis based on network pharmacology and molecular docking / 中国热带医学

@#Abstract: Objective To elucidate the potential mechanism of Jindanjiangan Capsule in the treatment of liver fibrosis by network pharmacology and molecular docking. Methods Active ingredients and targets of Jindanjiangan Capsules were searched by Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and HERB databases, and the disease targets were screened by DisGeNET and Therapeutic Target Database (TTD) databases. The targets of the active ingredients of Jindanjiangan Capsule were matched with the disease targets, and the common targets were imported into the String database platform to construct a protein-protein interaction network (PPI) network. CytoNCA tool of Cytoscape 3.9.1 software was used for topological analysis to screen key targets. Traditional Chinese Medicine-Key Active IngredientsKey Target Network was constructed by Cytoscape 3.9.1 Software. KEGG enrichment analysis of key targets was performed through the DAVID platform. The molecular docking of active ingredients and targets was performed to verify the above results using LeDock software. Results By screening, 180 potential active ingredients and 1 340 targets of Jindanjiangan Capsule and 1 060 targets of liver fibrosis, and 273 common targets were obtained. 29 key targets related to liver fibrosis were screened out by PPI network interaction, and verified by KEGG analysis and molecular docking. Jindanjiangan capsule acts on key targets such as EGFR, MMP9, PTGS2, ESR1, PIK3CA, F2, PPARG, and PTPN11 through active components such as isovitexin, quercetin 7-O- β -D-glucoside, (3S, 6S) -3- (benzyl) -6- (4-hydroxybenzyl) piperazine-2, 5-quinone, 6-Osyringoyl-8-O-acetylshanzhiside methyl ester, tanshinone II, nortanshinone, capillaris chromone, and etanone. The specific mechanism may be related to HIF-1 signaling pathway, C-type lectin receptor signaling pathway, Toll-like receptor signaling pathway, tumor necrosis factor signaling pathway, relaxin signaling pathway, FoxO signaling pathway and so on. Conclusion Jindanjiangan capsule can effectively treat hepatic fibrosis through multi-component, multi-target and multi-pathway.

Spectrum-Effect Relationship Analysis of Bioactive Compounds in Zanthoxylum nitidum (Roxb.) DC. by Ultra-High Performance Liquid Chromatography Mass Spectrometry Coupled With Comprehensive Filtering Approaches.

Zanthoxylum nitidum (Roxb.) DC. (ZN), with strong effects of anti-inflammation and antioxidant activities is treated as a core herb in traditional Chinese medicine (TCM) preparation for treating stomachache, toothache, and rheumatoid arthritis. However, the active ingredients of ZN are not fully clarified due to its chemical complexity. In the present study, a double spectrum-effect analysis strategy was developed and applied to explore the bioactive components in herbs, and ZN was used as an example. Here, the chemical components in ZN were rapidly and comprehensively profiled based on the mass defect filtering-based structure classification (MDFSC) and diagnostic fragment-ion-based extension approaches. Furthermore, the fingerprints of 20 batches of ZN samples were analyzed by high-performance liquid chromatography, and the anti-inflammatory and antioxidant activities of the 20 batches of ZN samples were studied. Finally, the partial least squares regression (PLSR), gray relational analysis models, and Spearman's rank correlation coefficient (SRCC) were applied to discover the bioactive compounds in ZN. As a result, a total of 48 compounds were identified or tentatively characterized in ZN, including 35 alkaloids, seven coumarins, three phenolic acids, two flavonoids, and one lignan. The results achieved by three prediction models indicated that peaks 4, 12, and 17 were the potential anti-inflammatory compounds in ZN, whereas peaks 3, 5, 7, 12, and 13 were involved in the antioxidant activity. Among them, peaks 4, 5, 7, and 12 were identified as nitidine, chelerythrine, hesperidin, and oxynitidine by comparison with the standards and other references. The data in the current study achieved by double spectrum-effect analysis strategy had great importance to improve the quality standardization of ZN, and the method might be an efficiency tool for the discovery of active components in a complex system, such as TCMs.

Rapid screening of glycosyltransferases in plants using a linear DNA expression template based cell-free transcription-translation system.

Plants have an extensively large number of enzymes including glycosyltransferases that are important in the biosynthesis of natural products. However, it is time-consuming and challenging to study these enzymes and only a small percentage of them have been well-characterized. Here, we report a rapid method to screen plant glycosyltransferases using a linear DNA expression template (LET) based cell-free transcription-translation system (TX-TL). As a proof of concept, we amplified and tested glycosyltransferases from Arabidopsis thaliana and showed that the catalytic activity results of these glycosyltransferases from LET-based-TX-TL were consistent with previous studies. We then chose a local medicinal plant Anoectochilus roxburghii, acquired its transcriptome sequences, and applied this method to study its glycosyltransferases. We rapidly expressed all the putative UDP-glucose glycosyltransferases using LET-based-TX-TL and discovered 6 unreported active glycosyltransferases which can catalyze the glycosylation of quercetin into isoquercitrin. Thus, LET-based-TX-TL was shown to be a powerful tool for researchers to rapidly screen plant glycosyltransferases for the first time.

Derivatization of Soyasapogenol A through Microbial Transformation for Potential Anti-inflammatory Food Supplements.

For the optimum use of soyasaponins isolated from soybean cake and to explore the potential anti-inflammatory agents from pentacyclic triterpenes as natural food supplements, microbial transformation of soyasapogenol A was carried out. Four strains of microbes, including Bacillus megaterium CGMCC 1.1741, Penicillium griseofulvum CICC 40293, Bacillus subtilis ATCC 6633, and Streptomyces griseus ATCC 13273, showed robust catalytic capacity to the substrate. Preparative biotransformation and column chromatographic purification led to the isolation of 10 novel and 1 reported metabolites. The structure elucidation was performed using 1D/2D NMR and HR-ESI-MS analytical method. Several novel tailoring reactions, such as allyl oxidation, C-C double bond rearrangement, hydroxylation, dehydrogenation, and glycosylation, were observed in the biotransformation. In the follow-up bioassay, most of the metabolites exhibited low cytotoxicity and potent inhibitory activity against the production of nitric oxide (NO) in RAW 264.7 cells stimulated by lipopolysaccharide. Especially compound 6 (3-oxo-11α,21ß,22ß,24-tetrahydroxy-olean-12-ene) showed comparable activity to the positive control of quercetin with an IC50 value of 16.70 µM. These findings provided an experimental approach to achieve the derivatization of natural aglycons in soybeans through microbial transformation for developing potent anti-inflammatory food supplements.

Biotransformation of Erythrodiol for New Food Supplements with Anti-Inflammatory Properties.

Erythrodiol, a typical pentacyclic triterpenic diol in olive oil and its byproduct, olive pomace, frequently appears in food additives for the prevention of cardiovascular diseases because of its antioxidation, anti-inflammatory, and antitumor activities. To develop new derivatives of erythrodiol (1), preparative biotransformations were investigated through Streptomyces griseus ATCC 13273, Penicilium griseofulvum CICC 40293, and Bacillus subtilis ATCC 6633, and ten new (1a-1j) and one known metabolites were isolated. Their structures were elucidated by high resolution electrospray ionization mass spectrometry (HR-ESI-MS) and one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy. Furthermore, relative to 1, most metabolites exhibited lower toxicity and more potent inhibitory activities against nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. In particular, the glycosylated metabolite 1k showed a dramatically increased inhibitory effect with an IC50 value of 2.40 µM, which is even lower than that of quercetin. Thus, biotransformation of erythrodiol is a viable strategy for discovering new triterpenes as food supplements with anti-inflammatory properties.

New phloroglucinol derivatives with protein tyrosine phosphatase 1B (PTP1B) inhibitory activities from Syzygium austroyunnanense.

Five new phloroglucinol derivatives (1-5) together with one known analogue (6) were isolated from the leaves of Syzygium austroyunnanense which is an edible folk medicine used for the treatment of diabetes. The new structures were elucidated as austroyunones A - E (1-5) by means of the extensive spectroscopic analyses including high-resolution electrospray ionization mass spectrometry (HRESIMS) and 1D and 2D nuclear magnetic resonance (NMR). Compounds 4-6 showed obvious protein tyrosine phosphatase 1B (PTP1B) inhibitory activity. This discovery of new phloroglucinols and their bioactivities provided a scientific basis for the application of S. austroyunnanense as an edible and medicinal plant.

Synthesis of tigogenin MeON-Neoglycosides and their antitumor activity.

To discover new potent cytotoxic steroidal saponins, a series of tigogenin neoglycosides were synthesized via oxyamine neoglycosylation for the first time. The preliminary bioassays for their in vitro antitumor activities against five human cancer cell lines (A375, A-549, HCT-116, HepG2 and MCF-7) were conducted. The results revealed a sugar-dependent activity profile of their cytotoxicity, the glycoconjugation converted the non-active tigogenin to the most potential product Tg29 ((3R)-N-methoxyamino-tigogenin-ß-2-deoxy-d-galactoside) with IC50 value of 2.7µM and 4.6µM against HepG2 and MCF-7 cells respectively. And the 3R-tigogenin neoglycosides exhibited enhanced antitumor activity while the 3S-tigogenin almost showed no activity. Among the five cell lines, HepG2 and MCF-7 cells showed more sensitive cytotoxic responses to the products. Therefore, the neoglycosylation could be a promising strategy for the synthesis of antitumor steroidal saponins and it also proved the essential role of carbohydrate moiety of steroidal saponins in the biological activity.

Glycosylation and sulfation of emodin by Gliocladium deliquescens NRRL 1086.

The present study was designed to explore the substrate scope and biocatalytic capability of Gliocladium deliquescens NRRL 1086 on phenolic natural products. Emodin was subjected to the fermentation culture of Gliocladium deliquescens NRRL 1086 according to the standard two-stage protocol. The biotransformation process was monitored by HPLC-DAD-MS, the main product was isolated by column chromatography, and the structure was elucidated on the basis of NMR spectroscopy. Emodin could be fully metabolized by Gliocladium deliquescens NRRL 1086, resulting in high yield of emodin 6-O-ß-D-glucopyranoside and small amount of sulfated product. In conclusion, our results may provide a convenient method to prepare emodin 6-O-ß-D-glucopyranoside and the microbe catalyzed glucosylation/sulfation will give an inspiration to pharmacokinetic model studies in vitro.

[Effect of Combination Therapy of Tetramethylpyrazine with Methotrexate on Inflammatory Reac- tions and Hemorheology in Collagen-induced Arthritis Rats].

OBJECTIVE: To explore the effect of combination therapy of tetramethylpyrazine (TMP) with methotrexate (MTX) on collagen induced arthritis (CIA) rats. METHODS: Totally 55 male SD rats were stratified by body weight. Nine of them were randomly recruited as the normal control group. The rest 46 were immunized with type II bovine collagen (C II) for establishing rheumatoid arthritis (RA) model. Forty successfully modeled rats were randomly divided into 4 groups according to swollen toe degree, i.e., the CIA group, the TMP group, the MTX group, and the TMP plus MTX group, 10 in each group. Rats in the MTX group were administered with MTX (1. 2 mg/kg) , once per week for 4 continuous weeks. Those in the TMP group were administered with 40 mg/kg TMP, once per day for 10 continuous days, and then discontinued for 7 successive days, and continued for another 10 successive days. Rats in the TMP plus MTX group were administered with a mixture of equal dose MTX and TMP, and when MTX was discontinue, TMP was administered according to the way in the TMP group. Equal volume of saline solution was given to rats in the normal control group and the CIA group. Clinical parameters including ankle width (mediolateral diameter) and hindpaw swelling were measured at day 0, 4, 11, 18, and 26 after treatment. Rats were sacrificed 28 days after treatment, their knee joints and ankle joints were collected for pathological analyses. Serum levels of IL-1ß, IL-6, and IL-17A were detected by ELISA. Changes of fibrinogen (FIB) and platelet aggregation rate (PAg) were detected. RESULTS: Compared with the normal control group, the ankle width and hindpaw swelling increased significantly (P < 0.01), contents of FIB and PAg increased obviously (P < 0.05, P < 0.01), serum levels of IL-1ß, IL-6, and IL-17 increased remarkably (P <0. 01) in the CIA group. Obvious cell proliferation, inflammatory cell infiltration, hyperemia and edema of synovial tissues could be seen. Pannus formed and immerged in cartilages, resulting in necrosis. Compared with the model group, changes of ankle width and hindpaw swelling were all alleviated in each medicated group (P <0. 05, P <0. 01). Of them, the effect was superior in the MTX group to that of the TMP group and the MTX plus TMP group (P < 0.05, P < 0.01). Contents of FIB, serum levels of IL-1ß and IL-6 decreased significantly in the MTX group (P < 0.05). Contents of FIB, serum levels of IL-1ß and IL-6 decreased significantly in the TMP group and the MTX plus TMP group (P < 0.05). Besides, serum levels of FIB and IL-6 were obviously lower in the MTX plus TMP group than in the TMP group and the MTX group (P < 0.01). Levels of PAg and IL-17A were more significantly lowered in the TMP group than in the MTX plus TMP group and the MTX group. Pathological changes could be alleviated in each medicated group, with the optimal effect obtained in the MTX plus TMP group. CONCLUSION: Combination of TMP with MTX could significantly ameliorate inflammatory reactions and FIB contents of CIA rats.

[Effect of Chinese herbal drugs and tetrandrine on TGF-beta1 signaling pathway].

OBJECTIVE: To investigate the molecule mechanism of the anti-fibrotic effects of Chinese herbal drugs (Qidan granules) in rats. METHODS: The male rats were randomly divided into four experimental groups: normal group, model group, Qidan group, tetrandrine group. Every group had 10 rats. Normal group were treated with physiologic saline while others were treated with silicon dioxide (50 mg/rat) by intratracheal instillation to induce silicosis. On 30th day Qidan group and Tetrandrine group were treated with Qidan granules (3125 mg/kg) or treated with tetrandrine (22 mg/kg) respectively. All the rats were scarified after 5 months. Lung/body coefficient was measured. Content of hydroxyproline was measured by alkaline hydrolysis. The gene expression of transforming growth factor-beta1 in bronchoalveolar lavage fluid was examined by using enzyme-linked immunosorbent assay (ELISA). The gene expressions of transforming growth factor-beta1, transcription factor Smad 3 and Smad 7 in lung were analyzed by using immunohistochemical technique (SP) and the image analysis. RESULTS: Model group mainly had Grade III approximately IV silicotic nodule while Qidan group and tetrandrine group had Grade II silicotic nodule. In Qidan group and tetrandrine group, lung/body coefficient and content of hydroxyproline and expression of transforming growth factor-beta1 and Smad3 in lung and expression of transforming growth factor-beta1 in bronchoalveolar lavage fluid were lower than those in model group (P < 0.05). Expression of Smad 7 in lung was higher than model group (P < 0.05). Injury of kidney occurred in tetrandrine group. CONCLUSION: Qidan granules and tetrandrine could inhibit expression of both Smad 7 and transforming growth factor-beta1 and promote expression of Smad 3. Qidan granules and tetrandrine could inhibit remarkably silicotic fibrosis in rats. Qidan granules are safer than tetrandrine.

Expression profile of a PAL gene from Astragalus membranaceus var. Mongholicus and its crucial role in flux into flavonoid biosynthesis.

An important traditional Chinese medicine herb, Astragalus membranaceus var. Mongholicus, whose dried root is known as Radix astragali ("Huangqi" in Chinese), has high flavonoid content as an essential active constituent. Phenylalanine ammonia-lyase (PAL, EC 4.3.1.5) catalyzes the first and also a rate-limiting step in phenylpropanoid pathway, which supplies precursors for a variety of secondary metabolites including flavonoids. A PAL gene, designated AmPAL1 (GenBank accession no. AY986506), was isolated from A. membranaceus var. Mongholicus with a full-length cDNA of 2562 nucleotides and an open reading frame of 2154 bp. Northern blot analysis revealed that AmPAL1 expressed universally in different organs, and its expression was markedly induced by UV irradiation, mechanical wounding, and white light irradiation on etiolated seedlings, with some distinctive responsive properties. Content of a typical flavonoid, quercetin, in A. membranaceus var. Mongholicus of different ages correlated with PAL enzymatic activity. Transgenic tobacco plants harboring AmPAL1 under the control of the CaMV35S promoter showed significantly increased PAL activity and correlatively increased quercetin content than those in non-transformed plants. These results indicate that PAL is maybe a key point for flux into flavonoid biosynthesis in the genetic control of secondary metabolism in A. membranaceus var. Mongholicus.

Reversible inhibition of alpha-synuclein fibrillization by dopaminochrome-mediated conformational alterations.

Previous studies demonstrated that alpha-synuclein (alpha-syn) fibrillization is inhibited by dopamine, and studies to understand the molecular basis of this process were conducted (Conway, K. A., Rochet, J. C., Bieganski, R. M., and Lansbury, P. T., Jr. (2001) Science 294, 1346-1349). Dopamine inhibition of alpha-syn fibrillization generated exclusively spherical oligomers that depended on dopamine autoxidation but not alpha-syn oxidation, because mutagenesis of Met, His, and Tyr residues in alpha-syn did not abrogate this inhibition. However, truncation of alpha-syn at residue 125 restored the ability of alpha-syn to fibrillize in the presence of dopamine. Mutagenesis and competition studies with specific synthetic peptides identified alpha-syn residues 125-129 (i.e. YEMPS) as an important region in the dopamine-induced inhibition of alpha-syn fibrillization. Significantly, the dopamine oxidation product dopaminochrome was identified as a specific inhibitor of alpha-syn fibrillization. Dopaminochrome promotes the formation of spherical oligomers by inducing conformational changes, as these oligomers regained the ability to fibrillize by simple denaturation/renaturation. Taken together, these data indicate that dopamine inhibits alpha-syn fibrillization by inducing structural changes in alpha-syn that can occur through the interaction of dopaminochrome with the 125YEMPS129 motif of alpha-syn. These results suggest that the dopamine autoxidation can prevent alpha-syn fibrillization in dopaminergic neurons through a novel mechanism. Thus, decreased dopamine levels in substantia nigra neurons might promote alpha-syn aggregation in Parkinson's disease.