Five new diarylheptanoids from the rhizomes of Curcuma kwangsiensis and their antiproliferative activity

In vitro biological evaluation and in silico studies of linear diarylheptanoids from Curcuma aromatica Salisb. as urease inhibitors

Plants of the Zingiberaceae family, specifically those belonging to the Curcuma species, are commonly under consideration as potential therapeutic agents for the management of gastrointestinal diseases. In this study, we carried out a phytochemical study on Curcuma aromatica Salisb. (or so-called "Nghe trang" in Vietnamese) grown in Vietnam, which yields three newly discovered 3,5-diacetoxy diarylheptanoids (1-3) and six known 3,5-dihydroxyl diarylheptanoids (4-9). The bioactivity assessment shows that all isolated compounds, except compounds 3, 7, and 8, could inhibit urease. Compounds 4 and 9 significantly inhibit urease, with an IC50 value of 9.6 and 21.4 μM, respectively, more substantial than the positive control, hydroxyurea (IC50 = 77.4 μM). The structure-activity relationship (SAR) of linear diarylheptanoids was also established, suggesting that the hydroxyl groups at any position of skeleton diarylheptanoids are essential for exerting anti-urease action. Through a comparative analysis of the binding sites of hydroxyurea and diarylheptanoid compounds via our constructed in silico model, the mechanism of action of diarylheptanoid compounds is predicted to bind to the dynamic region close to the dinickel active center, resulting in a loss of catalytic activity. Such insights certainly help design and/or find diarylheptanoid-based compounds for treating gastric ulcers through inhibiting urease.

The dual-targeting mechanism of an anti-inflammatory diarylheptanoid from Curcuma zedoaria (Christm.) Roscoe with the capacity for β2-adrenoreceptor agonism and NLRP3 inhibition

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease characterized by symptoms of shortness of breath and chronic inflammation. Curcuma zedoaria (Christm.) Roscoe is a well-documented traditional medical herb that is frequently used in the treatment of COPD. Previously, we identified a diarylheptanoid compound (1-(4-hydroxy-5-methoxyphenyl)-7-(4,5-dihydroxyphenyl)-3,5-dihydroxyheptane; abbreviated as HMDD) from this herb that exhibited potent agonistic activity on β2-adrenergic receptors (β2 adrenoreceptor) that are present on airway smooth muscle cells. In this work, we used chemically synthesized HMDD compound, and confirmed its bioactivity on β2 adrenoreceptors. Then by a proteomics study and anti-inflammatory evaluation detections, we found that HMDD downregulated the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) signaling pathway and suppressed the NLRP3 receptor expression in RAW264.7 macrophages and in a COPD model in A549 lung carcinoma cells. HMDD also decreased nitric oxide production levels, and impacted other interleukins and the phosphorylation of NF-κB and ERK pathways. We performed molecular docking of HMDD on β2 adrenoreceptor and NLRP3 protein models. This work reports the anti-inflammatory effects of HMDD and suggests a dual-targeting mechanism of β2-adrenoreceptor agonism and NLRP3 inhibition. Such a mechanism scientifically supports the clinical uses of Curcuma zedoaria (Christm.) Roscoe in treating COPD, as it can simultaneously relieve persistent breathlessness and inflammation. HMDD can be considered as a potential non-steroidal anti-inflammatory drug in novel therapy design for the treatment of COPD and other inflammatory diseases.

Integration of Two-Dimensional Liquid Chromatography-Mass Spectrometry and Molecular Docking to Characterize and Predict Polar Active Compounds in Curcuma kwangsiensis

Curcuma kwangsiensis, one species of Curcumae zedoaria Ros. c, is a commonly used traditional Chinese medicine (TCM) for treating cardiovascular disease, cancer, asthma and inflammation. Polar compounds are abundant in water decoction, which would be responsible for critical pharmacological effects. However, current research on polar compounds in Curcumae zedoaria Ros. c remains scarce. In this study, the polar fraction from Curcuma kwangsiensis was firstly profiled on G protein-coupled receptor 109A (GPR109A), β2-adrenergic receptor (β2-AR), neurotensin receptor (NTSR), muscarinic-3 acetylcholine receptor (M3) and G protein-coupled receptor 35 (GPR35), which were involved in its clinical indications and exhibited excellent β2-AR and GPR109A receptor activities. Then, an offline two-dimensional reversed-phase liquid chromatography (RPLC) coupled with the hydrophilic interaction chromatography (HILIC) method was developed to separate polar compounds. By the combination of a polar-copolymerized XAqua C18 column and an amide-bonded XAmide column, an orthogonality of 47.6% was achieved. As a result of coupling with the mass spectrometry (MS), a four-dimensional data plot was presented in which 373 mass peaks were detected and 22 polar compounds tentatively identified, including the GPR109A agonist niacin. Finally, molecular docking of these 22 identified compounds to β2-AR, M3, GPR35 and GPR109A receptors was performed to predict potential active ingredients, and compound 9 was predicted to have a similar interaction to the β2-AR partial agonist salmeterol. These results were supplementary to the material basis of Curcuma kwangsiensis and facilitated the bioactivity research of polar compounds. The integration of RPLC×HILIC-MS and molecular docking can be a powerful tool for characterizing and predicting polar active components in TCM.

Antioxidant effects of diarylheptanoids from two Curcuma species

ABSTRACTSFive linear diarylheptanoids (1-5), including a new one (1), were isolated from the rhizomes of Curcuma kwangsiensis S. G. Lee et C. F. Liang, while four linear diarylheptanoids (6-9) and four cyclic diarylheptanoids (10-13) were isolated from the roots of Curcuma aromatica Salisb. Using the model of H₂O₂-induced PC12 cells, the antioxidant effects of these thirteen diarylheptanoids from these two traditional Chinese medicines from Curcuma genus of Zingiberaceae family were investigated. As result, they produced different efficiency on damaged cell viability, ROS, LDH, SOD, CAT, and GSH-Px, which were the six indexes related to oxidative stress. Further, the correlation between these six bio-indexes and 53 selected molecular descriptors of diarylheptanoids was determined by PLS regression analysis.

Identifying of Anti-Thrombin Active Components From Curcumae Rhizoma by Affinity-Ultrafiltration Coupled With UPLC-Q-Exactive Orbitrap/MS

Recent studies concerning products that originate from natural plants have sought to clarify active ingredients, which both explains the mechanisms of the function and aids in quality control during production. As a traditional functional plant, Curcumae Rhizoma (CR) has been proven to be effective in promoting blood circulation and removing blood stasis. However, the components that play a role in its huge compound library are still unclear. The present study aimed to develop a high-throughput screening method to identify thrombin inhibitors in CR and validate them by in vitro and in vivo experiments. The effect of CR on thrombin in HUVECs cells was determined by ELISA, then an affinity-ultrafiltration-UPLC-Q-Exactive Orbitrap/MS approach was applied. Agatroban and adenosine were used as positive and negative drugs respectively to verify the reliability of the established method. The in vitro activity of the compounds was determined by specific substrate S-2238. The in vivo effect of the active ingredients was determined using zebrafish. Molecular docking was used to understand the internal interactions between compounds and enzymes. ELISA results showed that CR had an inhibitory effect on thrombin. The screening method established in this paper is reliable, by which a total of 15 active compounds were successfully identified. This study is the first to report that C7, 8, and 11 have in vitro thrombin-inhibitory activity and significantly inhibit thrombosis in zebrafish models at a safe dose. Molecular docking studies were employed to analyze the possible active binding sites, with the results suggesting that compound 16 is likely a better thrombin inhibitor compared with the other compounds. Based on the affinity-ultrafiltration-UPLC-Q-Exactive Orbitrap/MS approach, a precisely targeted therapy method using bio-active compounds from CR might be successfully established, which also provides a valuable reference for targeted therapy, mechanism exploration, and the quality control of traditional herbal medicine.

Chemical profile and potential mechanisms of Huo-Tan-Chu-Shi decoction in the treatment of coronary heart disease by UHPLC-Q/TOF-MS in combination with network pharmacology analysis and experimental verification

Huo-Tan-Chu-Shi Decoction (HTCSD), a traditional Chinese medicine (TCM) prescription within Guangdong Provincial TCM Hospital (the largest TCM hospital in China), is used for effective clinical treatment of coronary heart disease (CHD) caused by phlegm-dampness syndrome with high incidence in the hot and humid climate of Lingnan region. However, its chemical components responsible for the therapeutic effects remain unclear, which restricts its application and further development. Hence, a detailed workflow, combing with UHPLC-Q/TOF-MS, network pharmacology analysis and experimental verification, was proposed and applied to characterize the chemical profile and potential mechanism of HTCSD against CHD. As a result, a total of 130 components from all six composed herbal medicines were characterized in a rapid and sensitive manner through UHPLC-Q/TOF-MS, of which 33 compounds were unambiguously confirmed with reference standards. Consequently, based on the integrated pharmacology network of "herbs-chemicals-targets-pathways-therapeutic effects", four chemicals (magnoflorine, menisperine, 13-hydroxyberberine, luteolin) with four CHD related targets (SRC, MAPK1, EGFR and AKT1) were considered as the key components and targets of HTCSD in the treatment of CHD. Furthermore, the effect of HTCSD was confirmed in animal experiments by enhancing the phosphorylation of MAPK, and the published literature and molecular binding results suggested that magnoflorine and luteolin tended to be the critical compounds involved in the process. Taken together, the characterization of chemical profile combined with network pharmacology analysis and experimental verification not only provided an efficient insight into the overall chemical profile of HTCSD but also revealed the potential pharmacological components and mechanisms of HTCSD against CHD, which laid a necessary chemical and biological basis for the discovery of in vivo bioactive components and the further revelation of functionary mechanism.

Anti-inflammatory and antinociceptive effects of Curcuma kwangsiensis and its bioactive terpenoids in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

"Curcumae Radix", the dried rhizomes of Curcuma kwangsiensis documented in Chinese pharmacopoeia, has been traditionally used for the treatment of inflammatory and pain diseases, such as jaundice and red urine, cleaning the heart-fire and depression, arthralgia, and dysmenorrhea. However, according to literature surveys, anti-inflammatory and antinociceptive studies of C. kwangsiensis have been seldom reported so far.

AIM OF THE STUDY

The current study focuses on the anti-inflammatory and antinociceptive effects of C. kwangsiensis and discovering the bioactive compounds for its traditional usages both in vivo and in vitro, which could provide scientific justification about its traditional use.

MATERIAL AND METHODS

The anti-inflammatory and antinociceptive assays of various layers (ME, EA, AQS) from C. kwangsiensis were achieved by carrageenan-induced paw edema and acetic acid-induced writhing animal models, respectively. The most bioactive part, EA layer was further phytochemically investigated by multiple step chromatography techniques. The structures of these isolates were unambiguously elucidated by means of extensive spectroscopic and chemical methods, and comparison with corresponding data of the reported literature. Four major sesquiterpenoids (4, 6, 14, and 15) were achieved for their anti-inflammatory and antinociceptive assays by the two aforementioned animal models in vivo. All the isolated compounds were evaluated for their anti-inflammatory effects via detecting inflammatory mediator releases (COX-2, IL-1β, and TNF-α) in RAW 264.7 macrophage cells induced by LPS.

RESULTS

The ME and EA layers significantly alleviated the paw edema caused by carrageenan and decreased the number of writhes induced by acetic acid at the dose of 200 and/or 100 mg/kg in comparison to the control group (p < 0.01/0.05), and the EA layer exhibited better activity than that of ME layer. Subsequent phytochemical investigation on EA layer of C. kwangsiensis exhibited that three new terpenoid compounds (1-3), identified as (12Z,14R)-7β-hydroxylabda-8(17),12-diene-14,15,16-triol (1), (12Z,14S)- 7β-hydroxlabda-8(17),12-diene-14,15,16-triol (2), and (4S)-hydroxy-(8)-methoxy-(5S)-(H)-guaia1(10),7(11)-dien-12,8-olide (3), together with twenty-two known analogs were isolated. Furthermore, four major sesquiterpenoids (4, 6, 14, and 15) significantly relieved the paw edema and number of writhes at 100 and/or 50 mg/kg (p < 0.05/0.01). Likewise, the majority of sesqui- and diterpenoids isolated could remarkably inhibited the secretion of inflammatory mediators (COX-2, IL-1β, and TNF-α) in LPS-stimulated RAW 264.7 macrophages cells at the concentration of 20 μg/mL, comparable to DXM used as the positive control. All the results suggested that EA layer from C. kwangsiensis possessed the anti-inflammatory and antinociceptive activities, and these sesqui- and diterpenoids could be the effective constituents responsible for relieving inflammation.

CONCLUSION

The present studies undoubtedly determined the anti-inflammatory and antinociceptive material basis of C. kwangsiensis, including the EA layer and its precise components, which presented equivalent or better anti-inflammatory effects than that of positive control (ASP/DXM) in vivo and in vitro. These results not only would account for scientific knowledge for traditional use of C. kwangsiensis, but also provide credible theoretical foundation for the further development of anti-inflammatory and antinociceptive agents.

Anti-tumor activity and linear-diarylheptanoids of herbal couple Curcumae Rhizoma-Sparganii Rhizoma and the single herbs

ETHNOPHARMACOLOGICAL RELEVANCE

Curcumae Rhizoma and Sparganii Rhizoma (CR-SR) are the classical herbal couple for activating blood circulation and treating tumor in clinics.

AIM OF THE STUDY

To investigate the anti-tumor activity and to clarify the bioactive ingredients of herbal couple CR-SR and the single herbs Curcumae Rhizoma (CR) and Sparganii Rhizoma (SR).

MATERIALS AND METHODS

The active fractions of CR-SR decoction were fractioned by column chromatography. And isolated compounds were characterized by IR, ESI-MS, 1D and 2D-NMR techniques. Detecting linear-diarylheptanoids in CR-SR, CR and SR was realized through UPLC-LTQ-Orbitrap MSⁿ, based on the fragmentation pathways established in this study, comparison with MS data of isolated compounds and references. The anti-tumor activities of different solvent fractions from CR-SR, CR and SR, as well as isolated ingredients were tested by CCK-8 method.

RESULTS

Ultimately, a new compound (1), having a sulfonic acid group at C-3, named demethoxyshogasulfonic acid, along with another structurally similar 17 known linear-diarylheptanoids were isolated. These linear-diarylheptanoids (1-18) were divided into 12 categories based on the differences of substituents at C-3 and C-5 on the straight chain of seven carbons. Six fragmentation pathways were established by summarizing MS data of the 18 isolated compounds collected from UPLC-MS. Based on that, and retention times and MS fragmentation ions, 47 linear-diarylheptanoids were identified in CR-SR and CR, in which 12 linear-diarylheptanoids were also detected in SR. Most importantly, 5 sulfonated linear-diarylheptanoids were new compounds detected in CR and CR-SR. And the biological assay indicated that compounds 1-4 and 12-15 significantly reduced the proliferation and inhibited colony formation of MCF-7 and HepG2 cells.

CONCLUSION

The new compound (1) exhibited good anti-cancer activity, which suggests that a great effort has to be paid to investigate the bioactivity of sulfonated compounds. The fractions of CR-SR decoction exhibited stronger anti-tumor activities than that of CR and SR against 5 different cancer cells. As for chemical composition, it is the first time to report that diarylheptanoids are in Sparganiaceae and the sulfonated compounds in Zingiberaceae. Moreover, the linear-diarylheptanoids found in SR which being tested to possess good anti-tumor activity, plus those compounds in CR enhance the capacity of CR-SR. It shows importance of TCM compatibility.

Diarylheptanoid from rhizomes of Curcuma kwangsiensis (DCK) inhibited imiquimod-induced dendritic cells activation and Th1/Th17 differentiation

BACKGROUND AND OBJECT

Dendritic cells (DCs) are critical for initiating the activation and differentiation of T cells in inflammatory diseases including psoriasis. Curcuma kwangsiensis S.G. Lee & C.F. Liang is a herb for treating psoriasis and we previously found Diarylheptanoid from rhizomes of Curcuma kwangsiensis (DCK) inhibited keratinocytes proliferation. However, it is unknown whether DCK influences DC functions. Thus we aimed to explore whether DCK affect the major immunological functions of DCs.

MATERIALS AND METHODS

Primary DCs derived from mouse bone marrow cells and spleen were used for examining their general immunological functions, and OVA-specific T cells from OT-II mice were used for examining the DC-mediated T-helper (Th) 1 and Th17 cells differentiation and effect.

RESULTS

We demonstrated DCK suppressed DC uptake of FITC-labeled ovalbumin (OVA) and DC maturation characterized by decreased MHCII, CD80 and CD86 following imiquimod (IMQ) stimulation. DCK also reduced DC expression of the lymphoid-homing chemokine receptor CCR7, and DC migration towards CCL21, the ligand for CCR7. Importantly, DCK significantly reduced the production of proinflammatory cytokines including IL-12, IL-6 and IL-1β by IMQ-stimulated DCs. Moreover, in the coculture of OVA_323-339 peptide-pulsed DCs and OVA-specific T cells from OT-II mice, DCK significantly inhibited T cell proliferation and the differentiation of Th1 and Th17 cells. Furthermore, DCK treatment greatly reduced phosphorylation of p65-associated cell signaling pathway in IMQ-stimulated DCs.

CONCLUSION

These data together demonstrate a potential role of DCK in suppressing the biological function of DCs, and provide a possible mechanism for understanding the effects of herb Curcuma kwangsiensis in treating psoriasis.

Characterization of diarylheptanoids: An emerging class of bioactive natural products

Diarylheptanoids are a class of secondary plant metabolites with a wide variety of bioactivity. Research on their phytochemistry and phytoanalysis is rapidly growing and the number of identified structures bearing the aryl-C₇-aryl skeleton is at present approaching 500. Historically, the yellow pigment curcumin has been characterized as the first diarylheptanoid and the extensive research on naturally occurring analogues is still ongoing. In this review, studies dealing with the characterization of linear and cyclic derivatives are discussed from the phytoanalytical point of view. Isolation, fractionation and purification strategies from natural sources along with their chromatographic behavior and structural characteristics are discussed. The role of various techniques used for the extraction (such as Soxhlet extraction, sonication, maceration/percolation, microwave-assisted extraction, supercritical carbon dioxide extraction); isolation (liquid-liquid extraction, column chromatographic techniques, preparative thin-layer and high-performance liquid chromatography, centrifugal partition chromatography, counter-current chromatography); separation (thin-layer chromatography, high-performance liquid chromatography, gas chromatography, capillary electrophoresis) and structural characterization (UV/Vis spectroscopy, infrared spectroscopy, X-ray crystallography, mass spectrometry, nuclear magnetic resonance spectroscopy and circular dichroism spectroscopy) are critically reviewed.

Curdione attenuates thrombin-induced human platelet activation: β1-tubulin as a potential therapeutic target

Rhizoma Curcumae, the dry rhizomes derived from Curcuma aromatica Salisb., are a classical Chinese medicinal herb used to activate blood circulation, remove blood stasis and alleviate pain. Our previous study proved that curdione, a sesquiterpene compound isolated from the essential oil of Curcuma aromatica Salisb. can inhibit platelet activation suggesting its significant anticoagulant and antithrombotic effects. However, the underlying mechanism of curdione mediated anti-platelet effect has not been fully elucidated. Platelet proteins extracted from washed human platelets, including normal group (treated with normal saline), thrombin group and curdione group were digested and analysed by nano ESI-LC-MS/MS. UniProt database and SIEVE software were employed to identify and reveal the differentially expressed proteins. Furthermore, possible mechanisms involved were explored by Ingenuity Pathway Analysis (IPA) Software and validated by western blot experiments. Twenty-two differentially expressed proteins between the normal and thrombin group were identified. Compared with the thrombin group, the curdione treatment was significantly down-regulated only 2 proteins (Talin1 and β1-tubulin). Bioinformatics analysis showed that Talin1 and β1-tubulin could be involved in the integrin signal pathway. The results of western blot analysis were consistent with that of the proteomics data. Vinculin, identified in IPA database was involved in the formation of cell cytoskeletal. The down-regulation of β1-tubulin facilitated the decrease in vinculin/Talin1. Curdione regulated the expression of vinculin and Talin1 by β1-tubulin affecting the integrin signalling pathway and eventually inhibiting platelet activation. The β1-tubulin may be a potential target of curdione, which attenuates thrombin-induced human platelet activation.

Structure- and isoform-specific glucuronidation of six curcumin analogs

1. In the present study, we aimed to characterize the glucuronidation of six curcumin analogs (i.e. RAO-3, RAO-8, RAO-9, RAO-18, RAO-19, and RAO-23) derived from galangal using human liver microsomes (HLM) and twelve expressed UGT enzymes. 2. Formation of glucuronide was confirmed using high-resolution mass spectrometry. Single glucuronide metabolite was generated from each of six curcumin analogs. The fragmentation patterns were analyzed and were found to differ significantly between alcoholic and phenolic glucuronides. 3. All six curcumin analogs except one (RAO-23) underwent significant glucuronidation in HLM and expressed UGT enzymes. In general, the methoxy group (close to the phenolic hydroxyl group) enhanced the glucuronidation liability of the curcumin analogs. 4. UGT1A9 and UGT2B7 were primarily responsible for the glucuronidation of two alcoholic analogs (RAO-3 and RAO-18). By contrast, UGT1A9 and four UGT2Bs (UGT2B4, 2B7, 2B15 and 2B17) played important roles in conjugating three phenolic analogs (RAO-8, RAO-9, and RAO-19). Interestingly, the conjugated double bonds system (in the aliphatic chain) was crucial to the substrate selectivity of gastrointestinal UGTs (i.e. UGT1A7, 1A8 and 1A10). 5. In conclusion, glucuronidation of six curcumin analogs from galangal were structure- and isoform-specific. The knowledge should be useful in identifying a curcumin analog with improved metabolic property.