Seasonal variations in metabolite profiling of the fruits of Ligustrum lucidum Ait

The gap-free genome assembly and multi-omics analyses illustrate the evolutionary history and the synthesis of medicinal components of Ligustrum lucidum

Ligustrum lucidum, an important ornamental and medicinal plant in the Oleaceae family, has become a globally notorious invasive species because of its high adaptability. However, the lack of a high quality genome has hindered the understanding of the genetic basis for its broad adaptability and the mechanisms of its medicinal component synthesis. In this study, we successfully assembled a gap free telomere to telomere genome of L. lucidum. Through the reconstruction of the phylogenetic tree, we presented evidence that Jasmineae diverged from Oleaceae earlier than Forsythieae, which challenges the existing phylogenetic relationships within Oleaceae. Comparative genomics has found that two rounds of gene family expansions in L. lucidum significantly increased the number of genes related to its biotic and abiotic stress resistances, which may lay the genetic foundation for its broad adaptability. Among the L. lucidum fruits from January to March in our investigation, the results of metabolome show that March may be the optimal harvesting time. By integrating genomic, transcriptomic, and metabolomic data, we identified candidate genes involved in the synthesis of compounds, such as specnuezhenide, salidroside, and oleanolic acid. This study provides valuable genomic resources for comparative genomics studies within Oleaceae and for the genetic research of L. lucidum.

Nuezhenide of the fruits of Nuzhenzi (Ligustrum lucidum Ait.) is a functional analog of ghrelin

ETHNOPHARMACOLOGICAL RELEVANCE

The dried fruit of Ligustrum lucidum Ait. (FLL), known as Nuzhenzi, is traditionally recognized for its anti-aging properties in Chinese medicine. Nuezhenide, a water-soluble secoiridoid present in FLL, has demonstrated various pharmacological activities including neuroprotection, enhancement of learning and memory, antiosteoporotic, and antiviral activities. These therapeutic benefits align with the anti-aging effects attributed to ghrelin, particularly in the modulation of growth hormone secretagogue receptor type 1a (GHSR-1a) signaling.

AIM OF THE WORK

This study aimed to investigate the potential of FLL extracts, particularly its major compound nuezhenide, as agonists of GHSR-1a, a receptor implicated in anti-aging mechanisms, utilizing a stable GHSR-1a-expressing cell line.

MATERIALS AND METHODS

HEK293T cells expressing GHSR-1a-mCherry were used to assess the effects of FLL extract and its major compound, nuezhenide, on cell viability and ERK1/2 signaling. Molecular docking simulations predicted the interaction between nuezhenide and the GHSR-1a binding pocket. The impact of nuezhenide on ERK1/2 phosphorylation was evaluated, along with the involvement of phospholipase C and calcium signaling in this process.

RESULTS

Molecular docking simulations indicated that nuezhenide could interact with the GHSR-1a receptor, similar to teaghrelin, another known ghrelin analog. Experimental data showed that FLL extracts and nuezhenide enhanced cell viability and ERK1/2 activation in GHSR1a-mCherry HEK293T cells. The effect was specifically mediated by GHSR-1a, as confirmed by SP-analog treatment. Further analysis revealed that nuezhenide-induced ERK1/2 activation is likely mediated through a phospholipase C-dependent pathway involving intracellular calcium release.

CONCLUSION

This study demonstrated for the first time that nuezhenide acts as a putative GHSR-1a agonist, promoting cell proliferation and activating ERK1/2 signaling via phospholipase C and calcium pathways. These findings support the traditional use of FLL as an anti-aging herbal remedy and suggest that nuezhenide could be developed as a therapeutic agent targeting GHSR-1a-mediated pathways.

Specnuezhenide ameliorates hepatic fibrosis via regulating SIRT6-Mediated inflammatory signaling cascades

ETHNOPHARMACOLOGICAL RELEVANCE

Ligustrum lucidum W.T. Aiton is a traditional Chinese medicine that has long been used with high hepatoprotective therapeutic and condition value. Specnuezhenide (SP), the standard prominent secoiridoid compound of Fructus Ligustri Lucidi may ameliorate hepatic inflammation in chronic liver diseases.

AIM OF THE STUDY

Regulating inflammation through SIRT6-P2X7R axis has caused the emergence of novel molecular mechanism strategies for reversing hepatic fibrosis. This study focused on the mechanism of SP in modulating the liver inflammatory microenvironment in hepatic fibrosis.

MATERIALS AND METHODS

C57BL/6 mice with hepatic fibrosis were stimulated with thioacetamide (TAA) prior to administration of SP. Hepatic stellate cells (HSCs) or normal mouse primary hepatocytes were exposed to transforming growth factor-β (TGF-β) treatment. Meanwhile, normal mouse bone marrow-derived macrophages (BMDMs) were treated with lipopolysaccharide/adenosine triphosphate (LPS/ATP), aiming to obtain the conditioned medium. HSCs and hepatocytes were transfected with SIRT6 knockdown vector (siRNA-SIRT6) to estimate the impact of SP on the SIRT6-P2X7R/NLRP3 signaling pathway.

RESULTS

SP suppressed the HSCs extracellular matrix (ECM) deposition as well as pro-inflammatory cytokine levels induced by the medium of BMDMs or TGF-β. In addition, SP also significantly up-regulated SIRT6, inhibited P2X7R-NLRP3 inflammasome in HSCs and hepatocytes, and functioned as MDL-800 (a SIRT6 agonist). SP reduced the hepatocytes pyroptosis and further prevented the occurrence of inflammatory response in the liver. SP could inhibit the activation of BMDMs and impede IL-1β and IL-18 from entering extracellular regions. Moreover, deficiency of SIRT6 in HSCs or hepatocytes reduced SP's regulation of P2X7R suppression. For TAA-treated mice, SP mitigated histopathological changes, ECM accumulation, EMT process, and NETs formation in hepatic fibrosis.

CONCLUSIONS

Therefore, SP decreased inflammatory response via SIRT6-P2X7R/NLRP3 pathway and suppressed fibrillogenesis. These findings supported SP as the novel candidate to treat hepatic fibrosis.

Ligustri Lucidi Fructus, a traditional Chinese Medicine: Comprehensive review of botany, traditional uses, chemical composition, pharmacology, and toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Ligustri Lucidi Fructus (LLF) is one of the usual Chinese herbs that has long been used with high therapeutic and condition value. LLF is used for the treatment of dizziness and tinnitus, soreness and weakness of the waist and knees, premature greying of the hair, the darkness of the eyes, internal heat and thirst, bone steam and hot flashes and other symptoms.

AIM OF THE STUDY

This review reviews botany, traditional uses, processing, phytochemistry, quality control, pharmacology, toxicity and pharmacokinetics to better understand its therapeutic potential.

MATERIALS AND METHODS

The literature on LLF was obtained from Google Scholar and Baidu Scholar, PubMed, ScienceDirect, SciFinder, Web of Science, China National Knowledge Infrastructure (CNKI), WAN FANG DATA and libraries. Some local books, official websites, PhD or MS's dissertations were also included. Phytochemical constituents' structures were drawn by ChemDraw software.

RESULTS

So far, Multiple chemical components were isolated and identified from LLF, mainly including terpenoids and flavonoids. Modern studies have shown that LLF extracts and compounds have a wide range of pharmacological effects, including antitumor, liver protection, blood glucose, lipid-lowering, immune regulation, and other aspects.

CONCLUSIONS

LLF occupies an important position in the traditional medical system. It is cost-effective and is a significant plant with therapeutic applications in modern medicine. However, further in-depth studies are needed to determine the medical use of this plant and its chemical composition, pharmacological activity, quality control, toxicity and pharmacokinetics.

Specnuezhenide suppresses diabetes-induced bone loss by inhibiting RANKL-induced osteoclastogenesis

Diabetes osteoporosis is a chronic complication of diabetes mellitus (DM) and is associated with osteoclast formation and enhanced bone resorption. Specnuezhenide (SPN) is an active compound with anti-inflammatory and immunomodulatory properties. However, the roles of SPN in diabetic osteoporosis remain unknown. In this study, primary bone marrow macrophages (BMMs) were pretreated with SPN and were stimulated with receptor activator of nuclear factor kappa B ligand (RANKL; 50 ng/mL) to induce osteoclastogenesis. The number of osteoclasts was detected by tartrate-resistant acid phosphatase (TRAP) staining. The protein levels of cellular oncogene fos/nuclear factor of activated T cells c1 (c-Fos/NFATc1), nuclear factor kappa-B (NF-κB), and mitogen-activated protein kinases (MAPKs) were evaluated by western blot analysis. NF-κB luciferase assays were used to examine the role of SPN in NF-κB activation. The DM model group received a high-glucose, high-fat diet and was then intraperitoneally injected with streptozotocin (STZ). Micro-CT scanning, serum biochemical analysis, histological analysis were used to assess bone loss. We found that SPN suppressed RANKL-induced osteoclast formation and that SPN inhibited the expression of osteoclast-related genes and c-Fos/ NFATc1. SPN inhibited RANKL-induced activation of NF-κB and MAPKs. In vivo experiments revealed that SPN suppressed diabetes-induced bone loss and the number of osteoclasts. Furthermore, SPN decreased the levels of bone turnover markers and increased the levels of runt-related transcription factor 2 (RUNX2), osteoprotegerin (OPG), calcium (Ca) and phosphorus (P). SPN also regulated diabetes-related markers. This study suggests that SPN suppresses diabetes-induced bone loss by inhibiting RANKL-induced osteoclastogenesis, and provides an experimental basis for the treatment of diabetic osteoporosis.

Combination of UPLC-Q-TOF/MS and Network Pharmacology to Reveal the Mechanism of Qizhen Decoction in the Treatment of Colon Cancer

Traditional Chinese medicine (TCM) has been utilized for the treatment of colon cancer. Qizhen decoction (QZD), a potential compound prescription of TCM, possesses multiple biological activities. It has been proven clinically effective in the treatment of colon cancer. However, the molecular mechanism of anticolon cancer activity is still not clear. This study aimed to identify the chemical composition of QZD. Furthermore, a collaborative analysis strategy of network pharmacology and cell biology was used to further explore the critical signaling pathway of QZD anticancer activity. First, ultraperformance liquid chromatography-quadrupole time-of-flight/mass spectrometry (UPLC-Q-TOF/MS) was performed to identify the chemical composition of QZD. Then, the chemical composition database of QZD was constructed based on a systematic literature search and review of chemical constituents. Moreover, the common and indirect targets of chemical components of QZD and colon cancer were searched by multiple databases. A protein-protein interaction (PPI) network was constructed using the String database (https://www.string-db.org/). All of the targets were analyzed by Gene Oncology (GO) bioanalysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and the visual network topology diagram of "Prescription-TCM-Chemical composition-Direct target-Indirect target-Pathway" was constructed by Cytoscape software (v3.7.1). The top molecular pathway ranked by statistical significance was further verified by molecular biology methods. The results of UPLC-Q-TOF/MS showed that QZD had 111 kinds of chemical components, of which 103 were unique components and 8 were common components. Ten pivotal targets of QZD in the treatment of colon cancer were screened by the PPI network. Targets of QZD involve many biological processes, such as the signaling pathway, immune system, gene expression, and so on. QZD may interfere with biological pathways such as cell replication, oxygen-containing compounds, or organic matter by protein binding, regulation of signal receptors or enzyme binding, and affect cytoplasm and membrane-bound organelles. The main antitumor core pathways were the apoptosis metabolic pathway, the PI3K-Akt signal pathway, and so on. Expression of the PI3K-Akt signal pathway was significantly downregulated after the intervention of QZD, which was closely related to the inhibition of proliferation and migration of colon cancer cells by cell biology methods. The present work may facilitate a better understanding of the effective components, therapeutic targets, biological processes, and signaling pathways of QZD in the treatment of colon cancer and provide useful information about the utilization of QZD.

Analysis of chemical variations between raw and wine-processed Ligustri Lucidi Fructus by ultra-high-performance liquid chromatography-Q-Exactive Orbitrap/MS combined with multivariate statistical analysis approach

Ligustri Lucidi Fructus (LLF) is the dried and mature fruit of Ligubtrum lucidum Ait., which has the effect of nourishing the liver and kidney, brightening the eyes and promoting the growth of black hair. Wine-processed LLF is commonly used in traditional Chinese medicine; however, the processing mechanisms are still unclear. Herein, a system data acquisition and mining strategy was designed to investigate the chemical profile differences between the raw and wine-processed LLF, based on high-performance liquid chromatography-Orbitrap high resolution mass spectrometry coupled with multivariate statistical analysis including principal component analysis and partial least square analysis. Afterwars, a total of 55 components were found to be the main contributors to the significant difference between raw and wine-processed LLF by comparison with chromatographic behaviors, intact precursor ions, and characteristic MS fragmentation patterns. In addition, 10 main constituents of raw and wine-processed LLF were simultaneously determined by UHPLC-MS/MS for analyzing the content variations. Some structural transformation mechanisms during wine processing were deduced from the results. The results may provide a scientific foundation for deeply elucidating the wine-processing mechanism of LLF.

Dynamic Changes of Secondary Metabolites and Antioxidant Activity of Ligustrum lucidum During Fruit Growth

There are a number of secondary metabolites having medicinal values in Ligustri Lucidi Fructus. In this study, the target analytes salidroside, ligustroflavone, specnuezhenide, oleuropein, oleanolic acid and ursolic acid were chosen, aiming to establish a method to investigate the content of six compounds during eight growth stages of Ligustri Lucidi Fructus. Even though the results indicated that the contents of six compounds in different growth periods reached their maximum value, they displayed a downward trend. The antioxidant activity of the analyzed samples also decreased along with the growth period. The relationship between the content of six secondary metabolites and the activity has been elucidated. Hence, this research provides a theoretical basis for guiding efficient use of Ligustri Lucidi Fructus.

Metabolomics approach based on ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry to identify the chemical constituents of the Traditional Chinese Er-Zhi-Pill

Er-Zhi-Pill, which consists of Ligustri lucidi fructus and Ecliptae prostratae herba, is a classical traditional Chinese medicinal formulation widely used as a liver-nourishing and kidney-enriching tonic. To identify the bioactive ingredients of Er-Zhi-Pill and characterize the variation of chemical constituents between co-decoction and mix of individually decocted L. lucidi fructus and E. prostratae herba, a novel metabolomics approach based on ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry in both positive and negative ion modes, was established to comprehensively analyze chemical constituents and probe distinguishable chemical markers. In total, 68 constituents were unambiguously or tentatively identified through alignment of accurate molecular weights within an error margin of 5 ppm, elemental composition and fragmentation characteristics, including eight constituents, which were confirmed by comparing to reference standards. Furthermore, principal component analysis and partial least squares discriminant analysis using Simca-p+ 12.0 software were applied to investigate chemical differences between formulations obtained by co-decoction and a mixture of individual decoctions. Global chemical differences were found in samples of two different decoction methods, and 16 components, including salidroside, specneuzhenide and wedelolactone, contributed most to the observed differences. This study provides a basic chemical profile for the quality control and further mechanism research of Er-Zhi-Pill.

Application of UHPLC-ESI-Q-TOF-MS to Identify Multiple Constituents in Processed Products of the Herbal Medicine Ligustri Lucidi Fructus

Ligustri Lucidi Fructus (LLF), the fruit of Ligustrum lucidum Ait. (Oleaceae), has been used as a common herbal medicine in clinical practice in China for nearly 2000 years. In most cases, LLF is prescribed in decoctions in the form of processed products rather than crude drugs. In this study, an ultra-high performance liquid chromatography coupled with electrospray ionization-quadrupole-time of flight-mass spectrometry (UHPLC-ESI-Q-TOF-MS) method was established for rapid separation and identification of multiple constituents in the 80% methanol extract of processed-LLF. A total of 50 compounds (one phenylethanoid, seven phenylethanoid glycosides, seven flavonoids, 25 iridoids, nine triterpenoids and one cyclohexanecarboxylic acid) were either unambiguously identified or tentatively characterized with the aid of authentic standards or published data. Luteolin-7-O-rutinoside, oleoside and secologanoside were detected in LLF for the first time. This study enriches the chemical profiling of processed-LLF and could provide valuable information for the quality control and further investigation of processed-LLF and crude LLF.

Inhibition of Hypoxia-Induced Retinal Angiogenesis by Specnuezhenide, an Effective Constituent of Ligustrum lucidum Ait., through Suppression of the HIF-1α/VEGF Signaling Pathway

Specnuezhenide (SPN), one of the main ingredients of Chinese medicine "Nü-zhen-zi", has anti-angiogenic and vision improvement effects. However, studies of its effect on retinal neovascularization are limited so far. In the present study, we established a vascular endothelial growth factor A (VEGFA) secretion model of human acute retinal pigment epithelial-19 (ARPE-19) cells by exposure of 150 μM CoCl₂ to the cells and determined the VEGFA concentrations, the mRNA expressions of VEGFA, hypoxia inducible factor-1α (HIF-1α) & prolyl hydroxylases 2 (PHD-2), and the protein expressions of HIF-1α and PHD-2 after treatment of 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1, 1.0 μg/mL) or SPN (0.2, 1.0 and 5.0 μg/mL). Furthermore, rat pups with retinopathy were treated with SPN (5.0 and 10.0 mg/kg) in an 80% oxygen atmosphere and the retinal avascular areas were assessed through visualization using infusion of ADPase and H&E stains. The results showed that SPN inhibited VEGFA secretion by ARPE-19 cells under hypoxia condition, down-regulated the mRNA expressions of VEGFA and PHD-2 slightly, and the protein expressions of VEGFA, HIF-1α and PHD-2 significantly in vitro. SPN also prevented hypoxia-induced retinal neovascularization in a rat model of oxygen-induced retinopathy in vivo. These results indicate that SPN ameliorates retinal neovascularization through inhibition of HIF-1α/VEGF signaling pathway. Therefore, SPN has the potential to be developed as an agent for the prevention and treatment of diabetic retinopathy.

Characterization of antioxidant phenolics in Syringa vulgaris L. flowers and fruits by HPLC-DAD-ESI-MS

In this study the polyphenolic composition of lilac flowers and fruits was determined for the first time. For the identification of compounds, accurate molecular masses and formulas, acquired by LC and ESI-TOF-MS and fragmentation pattern given by LC-ESI/MS/MS analyses, were used. Our chromatographic system in conjunction with tandem MS was found to be valuable in the rapid separation and determination of the multiple constituents in methanolic extracts of lilac flowers and fruits. Altogether 34 phenolics, comprising 18 secoiridoids, seven phenylpropanoids, four flavonoids and five low-molecular-weight phenols, were identified. As marker compounds two secoiridoids (oleuropein and nuzhenide), two phenylpropanoids (acteoside and echinacoside) and rutin were quantified by validated methods. As a result of quantitative analysis, it was confirmed that flowers contain significant amounts of phenylpropanoids (acteoside, 2.48%; echinacoside, 0.75%) and oleuropein (0.95%), while in fruits secoiridoid oleuropein (1.09%) and nuzhenide (0.42%) are the major secondary metabolites. The radical scavenging activities of the extracts and the constituents were investigated by DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS [2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid)] assays. Both extracts show remarkable antioxidant activities. Our results clearly show that lilac flowers and fruits are inexpensive, readily available natural sources of phenolic compounds with pharmacological and cosmetic applications. Copyright © 2015 John Wiley & Sons, Ltd.

HPLC-ESI-QTOF-MS as a powerful analytical tool for characterising phenolic compounds in olive-leaf extracts

INTRODUCTION

Olea europaea L. leaves may be considered a cheap, easily available natural source of phenolic compounds. In a previous study we evaluated the possibility of obtaining bioactive phenolic compounds from olive leaves by pressurised liquid extraction (PLE) for their use as natural anti-oxidants. The alimentary use of these kinds of extract makes comprehensive knowledge of their composition essential.

OBJECTIVE

To undertake a comprehensive characterisation of two olive-leaf extracts obtained by PLE using high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS).

METHOD

Olive leaves were extracted by PLE using ethanol and water as extraction solvents at 150°C and 200°C respectively. Separation was carried out in a HPLC system equipped with a C₁₈-column working in a gradient elution programme coupled to ESI-QTOF-MS operating in negative ion mode.

RESULTS

This analytical platform was able to detect 48 compounds and tentatively identify 31 different phenolic compounds in these extracts, including secoiridoids, simple phenols, flavonoids, cinnamic-acid derivatives and benzoic acids. Lucidumoside C was also identified for the first time in olive leaves.

CONCLUSION

The coupling of HPLC-ESI-QTOF-MS led to the in-depth characterisation of the olive-leaf extracts on the basis of mass accuracy, true isotopic pattern and tandem mass spectrometry (MS/MS) spectra. We may conclude therefore that this analytical tool is very valuable in the study of phenolic compounds in plant matrices.