Enzymatic synthesis of Vaccinium blue using vaccinoside as a bifunctional precursor

Since Tang dynasty in China, the fresh leaves of Vaccinium bracteatum (VBL) have been applied as natural pigment to produce black rice. However, detailed information on its biosynthetic mechanism still remained unclear. Following rice dyeing capacity assay, vaccinoside, one of iridoid glycosides, was identified as the key active compound. Increased methodical research demonstrated vaccinoside as a distinct bifunctional precursor, which could be catalyzed by polyphenol oxidase or β-glucosidase independently, followed by reaction with 15 amino acids to give blue pigments (VBPs; λmax 581-590 nm) of different hues. Two synthetic pathways of VBPs were proposed, using multiple techniques such as HPLC, HPSEC, UV-Vis spectrum and colorimeter as analysis tools. Black rice was interpreted to be prepared by cooking, using vaccinoside, intrinsic enzymes from fresh VBL and rice protein in combination. These findings promote the understanding of VBP formation mechanisms and provide an efficient method of producing novel Vaccinium blue pigments.

Study on the Neuroprotective Effects of Eight Iridoid Components Using Cell Metabolomics

Iridoid components have been reported to have significant neuroprotective effects. However, it is not yet clear whether the efficacy and mechanisms of iridoid components with similar structures are also similar. This study aimed to compare the neuroprotective effects and mechanisms of eight iridoid components (catalpol (CAT), genipin (GE), geniposide (GEN), geniposidic acid (GPA), aucubin (AU), ajugol (AJU), rehmannioside C (RC), and rehmannioside D (RD)) based on corticosterone (CORT)-induced injury in PC12 cells. PC12 cells were randomly divided into a normal control group (NC), model group (M), positive drug group (FLX), and eight iridoid administration groups. Firstly, PC12 cells were induced with CORT to simulate neuronal injury. Then, the MTT method and flow cytometry were applied to evaluate the protective effects of eight iridoid components on PC12 cell damage. Thirdly, a cell metabolomics study based on ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q/TOF-MS) was performed to explore changes in relevant biomarkers and metabolic pathways following the intervention of administration. The MTT assay and flow cytometry analysis showed that the eight iridoid components can improve cell viability, inhibit cell apoptosis, reduce intracellular ROS levels, and elevate MMP levels. In the PCA score plots, the sample points of the treatment groups showed a trend towards approaching the NC group. Among them, AU, AJU, and RC had a weaker effect. There were 38 metabolites (19 metabolites each in positive and negative ion modes, respectively) identified as potential biomarkers during the experiment, among which 23 metabolites were common biomarkers of the eight iridoid groups. Pathway enrichment analysis revealed that the eight iridoid components regulated the metabolism mainly in relation to D-glutamine and D-glutamate metabolism, arginine biosynthesis, the TCA cycle, purine metabolism, and glutathione metabolism. In conclusion, the eight iridoid components could reverse an imbalanced metabolic state by regulating amino acid neurotransmitters, interfering with amino acid metabolism and energy metabolism, and harmonizing the level of oxidized substances to exhibit neuroprotective effects.

Cloning and Expression Analysis of Key Enzyme Gene CoGPPS Involved in Iridoid Glycoside Synthesis in Cornus officinalis

Cornus iridoid glycosides (CIGs), including loganin and morroniside, are the main active components of Cornus officinalis. As one of the key enzymes in the biosynthesis of CIGs, geranyl pyrophosphate synthase (GPPS) catalyzes the formation of geranyl pyrophosphate, which is the direct precursor of CIGs. In this study, the C. officinalis geranyl pyrophosphate synthase (CoGPPS) sequence was cloned from C. officinalis and analyzed. The cDNA sequence of the CoGPPS gene was 915 bp (GenBank No. OR725699). Phylogenetic analysis showed that CoGPPS was closely related to the GPPS sequence of Actinidia chinensis and Camellia sinensis, but relatively distantly related to Paeonia lactiflora and Tripterygium wilfordii. Results from the quantitative real-time PCR showed the spatiotemporal expression pattern of CoGPPS; that is, CoGPPS was specifically expressed in the fruits. Subcellular localization assay proved that CoGPPS was specifically found in chloroplasts. Loganin and morroniside contents in the tissues were detected by high-performance liquid chromatography, and both compounds were found to be at higher levels in the fruits than in leaves. Thus, this study laid the foundation for further studies on the synthetic pathway of CIGs.

Discovery of the toxicity-related quality markers and mechanisms of Zhi-Zi-Hou-Po decoction based on Chinmedomics combined with differentially absorbed components and network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Zhi-Zi-Hou-Po decoction (ZZHPD), as a representative traditional Chinese medicine (TCM) formula for the treatment of depression, has frequently triggered hepatorenal toxicity in recent years. However, its toxic effect, material basis, and underlying mechanisms have not been fully elucidated.

AIM OF THE STUDY

To explore the hepatorenal toxicity-material basis-quality markers (Q-markers) and multiple mechanisms of ZZHPD.

MATERIALS AND METHODS

ZZHPD-induced rat model of toxicity was evaluated by behavioral indicators, biochemical parameters, and histopathological sections. Then, UHPLC-Q-Exactive Orbitrap-MS combined with multivariate data analysis was utilized to identify the endogenous differential metabolites and the prototype components of ZZHPD in the plasma. A comprehensive strategy integrating in-house library, diagnostic ions, Compound Discover software, and network databases was constructed to identify the chemical constituents of ZZHPD. Additionally, the differentially absorbed components of ZZHPD were screened out based on the spectrum-effect relationship (toxic state and normal state), feature extraction of exogenous components, and variable influence on projection (VIP). Further, Chinmedomics and network pharmacology oriented by differentially absorbed components were performed to predict toxicity-related Q-markers and core targets, as well as relevant pathways. Finally, the binding ability between components and targets was predicted using molecular docking, and the mRNA expression of core target genes was determined by real-time qPCR experiment.

RESULTS

ZZHPD exerted significant hepatotoxicity and nephrotoxicity in rats accompanied by body weight loss, abnormal biochemical indicators, and pathologic characteristics with mild inflammation and cell damage. The results of plasma metabolomics indicated that 22 differential metabolites interfered by ZZHPD mainly involved in primary bile acid biosynthesis, arginine and proline metabolism, phenylalanine metabolism and biosynthesis, sphingolipid metabolism, pyrimidine and purine metabolism. Firstly, 106 chemical substances of ZZHPD were identified, 44 of them were absorbed into the blood, mainly including 7 iridoid glycosides, 15 flavonoids, 5 lignans, and others. Then, the correlation analysis results suggested that 12 of 19 differentially absorbed constituents were highly correlated with 22 differential metabolites and recognized as potential Q-markers. Finally, 9 toxicity-related Q-markers were predicted and confirmed with better binding ability to 5 core targets (PTGS2, CASP3, TNF, PPARG, HMOX1), including 3 flavonoids (naringin, hesperidin, and neohesperidin), 2 iridoid glycosides (geniposide and genipin-1-β-D-gentiobioside), 2 lignans (honokiol and magnolol), organic acid (chlorogenic acid), and crocin (crocetin). The real-time qPCR results showed that the mRNA levels of CASP3, TNF-α, and PPARG significantly increased in the damaged liver. Combining metabolomics and network pharmacology results, the multiple mechanisms of toxicity might involve in oxidative damage, inflammation, and apoptosis pathways.

CONCLUSION

Taken together, the toxicity-related Q-markers of ZZHPD screened for the first time in this work were reliable, and the holistic intervention for hepatorenal toxicity further revealed the multi-component, multi-target, and multi-pathway features in TCM. The integrated approach provides a novel perspective for the discovery of toxicity/efficacy-related substances and mechanistic studies in TCM.

Morroniside-mediated mitigation of stem cell and endothelial cell dysfunction for the therapy of glucocorticoid-induced osteonecrosis of the femoral head

BACKGROUND

Prolonged use of glucocorticoids (GCs) potentially lead to a condition known as GCs-induced osteonecrosis of the femoral head (GIONFH). The primary mechanisms underlying this phenomenon lies in stem cells and endothelial cells dysfunctions. Morroniside, an iridoid glycoside sourced from Cornus officinalis, possesses numerous biological capabilities, including combating oxidative stress, preventing apoptosis, opposing ischemic effects, and promoting the regeneration of bone tissue.

PURPOSE

This study aimed to analyze the impact of Morroniside on Dexamethasone (DEX)-induced dysfunction in stem cells and endothelial cells, and its potential as a therapeutic agent for GIONFH in rat models.

METHODS

ROS assay, JC-1 assay, and TUNEL assay were used to detect oxidative stress and apoptosis levels in vitro. For the evaluation of the osteogenic capability of bone marrow-derived mesenchymal stem cells, we employed ALP and ARS staining. Additionally, the angiogenic ability of endothelial cells was assessed using tube formation assay and migration assay. Microcomputed tomography analysis, hematoxylin-eosin staining, and immunohistochemical staining were utilized to evaluate the in vivo therapeutic efficacy of Morroniside.

RESULTS

Morroniside mitigates DEX-induced excessive ROS expression and cell apoptosis, effectively reducing oxidative stress and alleviating cell death. In terms of osteogenesis, Morroniside reverses DEX-induced osteogenic impairment, as evidenced by enhanced ALP and ARS staining, as well as increased osteogenic protein expression. In angiogenesis, Morroniside counteracts DEX-induced vascular dysfunction, demonstrated by an increase in tube-like structures in tube formation assays, a rise in the number of migrating cells, and elevated levels of angiogenic proteins. In vivo, our results further indicate that Morroniside alleviates the progression of GIONFH.

CONCLUSION

The experimental findings suggest that Morroniside concurrently mitigates stem cell and endothelial cell dysfunction through the PI3K/AKT signaling pathway both in vitro and in vivo. These outcomes suggest that Morroniside serves as a potential therapeutic agent for GIONFH.

Harpagide inhibits the TNF-α-induced inflammatory response in rat articular chondrocytes by the glycolytic pathways for alleviating osteoarthritis

Osteoarthritis (OA) causes severe and functional dysfunction due to abnormal inflammation. The objective of this study was to evaluate the effect of Harpagide (HPG) on TNF-α-induced inflammation in vitro and in vivo. The effect of HPG on the proliferation of rat chondrocytes was studied. The anti-inflammatory effect of HPG and its molecular mechanisms were elucidated by qPCR, Western blotting, flow cytometry, metabolome analysis in vitro. In addition, the OA rat model was established, and the effect of HPG on OA was verified in vivo. We revealed 10 μM HPG demonstrated biocompatibility. The results demonstrated that HPG restored the upregulation of MMP-13, COX2, IL-1β and IL-6 induced by TNF-α. Moreover, HPG reversed TNF-α induced degradation of the extracellular matrix of chondrocytes. TNF-α treatment induced down-regulation of the mRNA/protein levels of proliferative markers Bcl2, CDK1 and Cyclin D1 were also recovered. HPG can inhibit TNF-α-induced inflammatory response through glycolytic metabolic pathways. HPG can restore TNF-α-induced upregulation of GRP78/IRE1α, and downregulation of AMPK proteins. In vivo experiments demonstrated that after HPG treatment, the appearance and physiological structure of articular cartilage were more integrated with highly organized chondrocytes and rich cartilage matrix compared with OA group. Finally, the molecular docking of HPG and selected key factors in glycolysis results showed that HPG had good binding potential with PFKM, PFKP, PFKFB3, PKM, HK2, and PFKL. In conclusion, the results shown HPG protects and activates chondrocytes, inhibits TNF-α-induced inflammatory response by glycolysis pathway in rat articular chondrocytes, and plays a role in the treatment of OA.

Ethanol extract of Verbena officinalis alleviates MCAO-induced ischaemic stroke by inhibiting IL17A pathway-regulated neuroinflammation

BACKGROUND

The prevention and treatment of ischaemic stroke is a worldwide challenge, and effective clinical treatment strategies are lacking. Studies have demonstrated the efficacy of Verbena officinalis in managing cerebrovascular disorders. However, the neuroprotective bioactive components and mechanisms remain unclear.

PURPOSE

To investigate the pharmacological combinatorial components and mechanism underlying the anti-ischemic stroke effect of the ethanol extract of Verbena officinalis (VO Ex).

STUDY DESIGN AND METHODS

The components of VO Ex were identified by HPLC. A middle cerebral artery occlusion (MCAO) induced brain injury model was used to assess the therapeutic effect of VO Ex. The activity of the chemical components of VO Ex was evaluated using a primary astrocyte injury model induced by oxygen-glucose deprivation/reperfusion (OGD/R). RNA sequencing was used to reveal the potential targets of VO Ex against cerebral ischemia-reperfusion injury (CIRI), and the results were verified by qRT-PCR and western blotting. The key components and target binding ability were predicted by molecular docking. Finally, the mechanism of combinatorial components was verified by experiments.

RESULTS

The HPLC results indicated that the main ingredients of VO Ex were hastatoside, verbenalin, acteoside, luteolin, apigenin and hispidulin. In vivo experiments showed that VO Ex improved MCAO-induced acute cerebral ischemic injury. Transcriptomic data and biological experiments suggested that VO Ex exerted therapeutic effects through IL17A signalling pathways. The in vitro experiments indicated that verbenalin, acteoside, luteolin, apigenin and hispidulin exhibited neuroprotective activities. The novel formula of VALAH, derived from the aforementioned active ingredients, exhibited superior efficacy compared to each individual component. Molecular docking and mechanistic studies have confirmed that VALAH functions in the treatment of ischaemic stroke by suppressing the activation of the IL17A signalling pathway.

CONCLUSION

This work is the first to reveal that VO Ex effectively inhibits the IL17A signaling pathway and mitigates neuroinflammation following ischemic stroke. Moreover, we identified the novel formula VALAH as the bioactive combinatorial components for VO Ex. Further research suggests that the activity of VALAH is associated with IL17A-mediated regulation of neuroinflammation. This finding provides new insights into the efficacious components and mechanisms of traditional Chinese medicine.

A Comprehensive Phytochemical Analysis of Sideritis scardica Infusion Using Orbitrap UHPLC-HRMS

Sideritis scardica Griseb, also known as "mountain tea" and "Olympus tea" (Lamiaceae family) is an endemic plant from the mountainous regions of the Balkan Peninsula. In this study, we focused on an in-depth phytochemical analysis of S. scardica infusion using ultra-high-performance liquid chromatography hyphenated with high-resolution mass spectrometry (UHPLC-HRMS). Quantitative determination of the main secondary metabolites was carried out by UHPLC-HRMS analyses using the external standard method. The results revealed more than 100 metabolites, including five sugar acids and saccharides, 21 carboxylic, hydroxybenzoic, hydroxycinnamic acids, and derivatives, 15 acylquinic acids, 10 phenylpropanoid glycosides, four iridoid glycosides, 28 flavonoids, seven fatty acids, and four organosulfur compounds. Furthermore, a dereplication and fragmentation patterns of five caffeic acids oligomers and four acylhexaric acids was performed for the first time in S. scardica. Regarding the quantitative analysis, the phenylethanoid verbascoside (53) (151.54 ± 10.86 mg/g lyophilized infusion, li), the glycosides of isoscutellarein (78) (151.70 ± 14.78 mg/g li), methylisoscutelarein (82) (107.4 ± 9.07 mg/g li), and hypolaetin (79) (78.33 ± 3.29 mg/g li), as well as caffeic acid (20) (87.25 ± 6.54 mg/g li), were found to be the major compounds in S. scardica infusion. The performed state-of-the-art phytochemical analysis of S. scardica provides additional knowledge for the chemical constituents and usage of this valuable medicinal plant.

Analysis of Differences in the Chemical Composition of Glycosides and Sugars between Four Forms of Fresh Rehmanniae Radix

Fresh Rehmanniae Radix, as well as its processed products, are widely used in the clinical practice of traditional Chinese medicine. It is mainly available in four forms: fresh Rehmanniae Radix, raw Rehmanniae Radix, prepared Rehmanniae Radix, and nine-steamed, nine-dried Rehmanniae Radix. Pharmacological studies have shown that all Rehmanniae Radix forms contain iridoid glycosides and sugar compounds with various effects, including hypoglycemic, anti-inflammatory, neuroprotective, immunological enhancement, and bone marrow hematopoiesis-promoting activities. Differences in the efficacy among these Rehmanniae Radix forms and their processed products have been attributed to variations in their chemical compositions, particularly in iridoid glycosides and sugar compounds; however, the specific compositional differences in glycosides and sugars among the four forms of Rehmanniae Radix have not been clarified. Therefore, this study aims to qualitatively characterize the iridoid glycosides and sugar compounds in fresh Rehmanniae Radix, raw Rehmanniae Radix, prepared Rehmanniae Radix, and nine-steamed, nine-dried Rehmanniae Radix.

Sweroside: An iridoid glycoside of potential neuroprotective, antidiabetic, and antioxidant activities supported by molecular docking

Oxidative stress can be a series burden on human health and may lead to many chronic diseases such as diabetes and neurological disorders. The use of natural products to scavenge the reactive oxygen species has attracted the attention of many researchers, to safely manage these conditions with fewer side effects, in available and cost-effective ways. The current study aimed at the isolation and structure elucidation of sweroside from Schenkia spicata (Gentianaceae) and the evaluation of its antioxidant, antidiabetic, neuroprotective, and enzyme inhibitory potential via in vitro and in silico studies. The antioxidant potential was evaluated by a variety of assays as ABTS, CUPRAC and FRAP, showing values of 0.34 ± 0.08, 21.14 ± 0.43, and 12.32 ± 0.20 mg TE/g, respectively, while demonstrating 0.75 ± 0.03 mmol TE/g for phosphomolybdenum (PBD) assay. Acetylcholinestrase (AChE), butyrylcholinesterase (BChE) and tyrosinase inhibitory activities were used to evaluate the neuroprotective effect, while the antidiabetic potential was evaluated by measuring α-amylase and glucosidase inhibitory activities. Results revealed that sweroside showed antioxidant and inhibitory effects on the enzymes tested with the exception of AChE. It demonstrated good tyrosinase inhibitory ability with 55.06 ± 1.85 mg Kojic acid equivalent /g. Regarding the antidiabetic ability, the compound displayed both amylase and glucosidase (0.10 ± 0.01 and 1.54 ± 0.01 mmol Acarbose equivalent/g, respectively) inhibitory activities. Molecular docking studies of sweroside on the active sites of the aforementioned enzymes in addition to NADPH oxidase were performed using Discovery Studio 4.1 software. Results revealed good binding affinities of sweroside to these enzymes mainly through hydrogen bonds and van der Waals interactions. Sweroside can be an important antioxidant and enzyme inhibitory supplement, yet further in vivo and clinical studies are required.

Progress of research into the pharmacological effect and clinical application of the traditional Chinese medicine Rehmanniae Radix

The traditional Chinese medicine (TCM) Rehmanniae Radix (RR) refers to the fresh or dried root tuber of the plant Rehmannia glutinosa Libosch of the family Scrophulariaceae. As a traditional Chinese herbal medicine (CHM), it possesses multiple effects, including analgesia, sedation, anti-inflammation, antioxidation, anti-tumor, immunomodulation, cardiovascular and cerebrovascular regulation, and nerve damage repair, and it has been widely used in clinical practice. In recent years, scientists have extensively studied the active components and pharmacological effects of RR. Active ingredients mainly include iridoid glycosides (such as catalpol and aucuboside), phenylpropanoid glycosides (such as acteoside), other saccharides, and unsaturated fatty acids. In addition, the Chinese patent medicine (CPM) and Chinese decoction related to RR have also become major research subjects for TCM practitioners; one example is the Bolus of Six Drugs, which includes Rehmannia, Lily Bulb and Rehmannia Decoction, and Siwu Decoction. This article reviews recent literature on RR; summarizes the studies on its chemical constituents, pharmacological effects, and clinical applications; and analyzes the progress and limitations of current investigations to provide reference for further exploration and development of RR.

Two new iridoid glycosides from Hedyotis diffusa

Two new iridoid glycosides, named productasperulosidic acid butyl ester (1) and E-6-O-3-hydroxy-p-methoxycinnamoyl scandoside methyl ester (2), along with nine known ones (3-11), were isolated from Hedyotis diffusa Willd. The structures of them were elucidated by extensive 1D, 2D NMR and HR-ESI-MS spectral data. Compounds 1-11 showed no significant cytotoxic activity against HeLa cells.

The Iridoid Glycoside Loganin Modulates Autophagic Flux Following Chronic Constriction Injury-Induced Neuropathic Pain

Autophagy facilitates the degradation of organelles and cytoplasmic proteins in a lysosome-dependent manner. It also plays a crucial role in cell damage. Whether loganin affects autophagy in chronic constriction injury (CCI)-induced neuropathic pain remains unclear. We investigated the neuroprotective effect of loganin on the autophagic-lysosomal pathway in the rat CCI model. Sprague-Dawley rats were divided into sham, CCI, sham + loganin, and CCI + loganin. Loganin (5 mg/kg/day) was intraperitoneally injected once daily, and rats were sacrificed on day 7 after CCI. This study focused on the mechanism by which loganin modulates autophagic flux after CCI. CCI enhanced the autophagic marker LC3B-II in the ipsilateral spinal cord. The ubiquitin-binding protein p62 binds to LC3B-II and integrates into autophagosomes, which are degraded by autophagy. CCI caused the accumulation of p62, indicating the interruption of autophagosome turnover. Loganin significantly attenuated the expression of Beclin-1, LC3B-II, and p62. Double immunofluorescence staining was used to confirm that LC3B-II and p62 were reduced by loganin in the spinal microglia and astrocytes. Loganin also lessened the CCI-increased colocalization of both proteins. Enhanced lysosome-associated membrane protein 2 (LAMP2) and pro-cathepsin D (pro-CTSD) in CCI rats were also attenuated by loganin, suggesting that loganin improves impaired lysosomal function and autophagic flux. Loganin also attenuated the CCI-increased apoptosis protein Bax and cleaved caspase-3. Loganin prevents CCI-induced neuropathic pain, which could be attributed to the regulation of neuroinflammation, neuronal autophagy, and associated cell death. These data suggest autophagy could be a potential target for preventing neuropathic pain.

A novel iridoid glycoside leonuride (ajugol) attenuates airway inflammation and remodeling through inhibiting type-2 high cytokine/chemokine activity in OVA-induced asthmatic mice

BACKGROUND

Asthma is a chronic airway disorder with a hallmark feature of airflow obstruction that associated with the remodeling and inflammation in the airway wall. Effective therapy for controlling both remodeling and inflammation is still urgently needed. Leonuride is the main pharmacological component identified from Bu-Shen-Yi-Qi-Tang (BSYQT) which has been traditionally used in treatment of lung diseases. However, no pharmacological effects of leonuride in asthma were reported.

PURPOSE

Here we aimed to investigated whether leonuride provided a therapeutic efficacy in reversing asthma airway remodeling and inflammation and uncover the underlying mechanisms.

STUDY DESIGN AND METHODS

Mouse models of chronic asthma were developed with ovalbumin (OVA) exposure for 8 weeks. Respiratory mechanics, lung histopathology and asthma-related cytokines were examined. Lung tissues were analyzed using RNA sequencing to reveal the transcriptional profiling changes.

RESULTS

After oral administration with leonuride (15 mg/kg or 30 mg/kg), mice exhibited a lower airway hyperresponsiveness in comparison to asthmatic mice. Leonuride suppressed airway inflammation evidenced by the significant reductions in accumulation of inflammatory cells around bronchi and vessels, leukocyte population counts and the abundance of type 2 inflammatory mediators (OVA specific IgE, IL-4, IL-5 and IL-13) in bronchoalveolar lavage fluid (BALF). On the other hand, leonuride slowed down the process of active remodeling as demonstrated by weaker goblet cell metaplasia and subepithelial fibrosis in lung histopathology and lower transforming growth factor (TGF)-β1 levels in serum and BALF in comparison to mice treated with OVA only. Furthermore, we uncovered transcriptional profiling alternations in lung tissue of mice after OVA exposure and leonuride treatment. Gene sets belonging to type-2 cytokine/chemokine activity stood out in leonuride target transcripts. Those upregulated (Bmp10, Ccl12, Ccl22, Ccl8, Ccl9, Cxcl15, Il13, Il33, Tnfrsf9, Il31ra, Il5ra, Il13ra2 and Ccl24) or downregulated (Acvr1c and Il18) genes in asthmatic mice, were all reversely regulated by leonuride treatment.

CONCLUSIONS

Our results revealed the therapeutic efficacy of leonuride in experimental chronic asthma for the first time, and implied that its anti-inflammatory and antifibrotic properties might be mediated by regulation of type-2 high cytokine/chemokines responses.

The Fight against Infection and Pain: Devil’s Claw (Harpagophytum procumbens) a Rich Source of Anti-Inflammatory Activity: 2011–2022

Harpagophytum procumbens subsp. procumbens (Burch.) DC. ex Meisn. (Sesame seed Family—Pedaliaceae) is a popular medicinal plant known as Devil’s claw. It is predominantly distributed widely over southern Africa. Its impressive reputation is embedded in its traditional uses as an indigenous herbal plant for the treatment of menstrual problems, bitter tonic, inflammation febrifuge, syphilis or even loss of appetite. A number of bioactive compounds such as terpenoids, iridoid glycosides, glycosides, and acetylated phenolic compounds have been isolated. Harpagoside and harpagide, iridoid glycosides bioactive compounds have been reported in countless phytochemical studies as potential anti-inflammatory agents as well as pain relievers. In-depth studies have associated chronic inflammation with various diseases, such as Alzheimer’s disease, obesity, rheumatoid arthritis, type 2 diabetes, cancer, and cardiovascular and pulmonary diseases. In addition, 60% of chronic disorder fatalities are due to chronic inflammatory diseases worldwide. Inflammation and pain-related disorders have attracted significant attention as leading causes of global health challenges. Articles published from 2011 to the present were obtained and reviewed in-depth to determine valuable data findings as well as knowledge gaps. Various globally recognized scientific search engines/databases including Scopus, PubMed, Google Scholar, Web of Science, and ScienceDirect were utilized to collect information and deliver evidence. Based on the literature results, there was a dramatic decrease in the number of studies conducted on the anti-inflammatory and analgesic activity of Devil’s claw, thereby presenting a potential research gap. It is also evident that currently in vivo clinical studies are needed to validate the prior massive in vitro studies, therefore delivering an ideal anti-inflammatory and analgesic agent in the form of H. procumbens products.

Identification and functional characterization of three iridoid synthases in Gardenia jasminoides

The discovery of three iridoid synthases (GjISY, GjISY2 and GjISY4) from Gardenia jasminoides and their functional characterization increase the understanding of iridoid scaffold/iridoid glycoside biosynthesis in iridoid-producing plants. Iridoids are a class of noncanonical monoterpenes that are found naturally in the plant kingdom mostly as glycosides. Over 40 iridoid glycosides (e.g., geniposide, gardenoside and shanzhiside) have been isolated from Gardenia jasminoides. They have multiple pharmacological properties and health-promoting effects. However, their biosynthetic pathway is poorly understood, and the iridoid synthase (ISY) responsible for the cyclization of the core scaffold remains unclear. In this study, three homologs of ISYs from G. jasminoides (GjISY, GjISY2 and GjISY4) were identified on the basis of transcriptomic data and functionally characterized. The genomic structure and intron-exon arrangement revealed that all three ISYs contained an intron. Biochemical assays indicated that all three recombinant enzymes reduced 8-oxogeranial to nepetalactol and its open forms (iridodials) as the products of the classical CrISY (Catharanthus roseus). In addition, all three enzymes reduced progesterone to 5-β-prognane-3,20-dione. However, only GjISY2 and GjISY4 reduced 2-cyclohexen-1-one to cyclohexanone. Overall, the GjISY2 expression levels in the flowers and fruits were similar to the GjISY and GjISY4 expression levels. By contrast, the GjISY2 expression levels in the upper and lower leaves were substantially higher than the GjISY and GjISY4 expression levels. Among the three, GjISY2 exhibited the highest catalytic efficiency for 8-oxogeranial. GjISY2 might be the major contributor to iridoid biosynthesis in G. jasminoides. Collectively, our results advance the understanding of iridoid scaffold/iridoid glycoside biosynthesis in G. jasminoides and provide a potential target for metabolic engineering and breeding.

Pterocephanoside A, a new iridoid from a traditional Tibetan medicine, Pterocephalus hookeri

This work obtained and identified pterocephanoside A (1), one new iridoid glucoside derivative with rare structure of three iridoid glycosides linked to cyclopenta[c]pyran-3(1H)-one, and 10 known iridoids (2-11) from Pterocephalus hookeri through silica gel column chromatography and semi-preparative HPLC. The structure of the new compound was confirmed by 1D and 2D NMR and HRMS data analysis. Compounds 1 and 2 were isolated from this plant for the first time. The iridoids mostly possessed seco-iridoid subtype and iridoid subtype skeletons from P. hookeri. Compounds 1, 3, 4, and 6-11 showed weak anti-inflammatory activity.

Kutkoside-an iridoid glycoside, exerts anti-proliferative effects in drug-resistant human oral carcinoma cells by targeting PI3K/AKT signalling pathway, inducing apoptosis and suppressing cell migration and invasion

The Editors of JBUON issue an Expression of Concern to ' Kutkoside-an iridoid glycoside, exerts anti-proliferative effects in drug-resistant human oral carcinoma cells by targeting PI3K/AKT signalling pathway, inducing apoptosis and suppressing cell migration and invasion', by Jun-Chi Hou, Xiao-Nan Xu, JBUON 2020;25(1):338-343; PMID: 32277652. Following the publication of the above article, readers drew to our attention that part of the data was possibly unreliable. We sent emails to the authors with a request to provide the raw data to prove the originality, but received no reply. Therefore, as we continue to work through the issues raised, we advise readers to interpret the information presented in the article with due caution. We thank the readers for bringing this matter to our attention. We apologize for any inconvenience it may cause.

Bioassay-Guided Isolation of Anti-Alzheimer Active Components from the Aerial Parts of Hedyotis diffusa and Simultaneous Analysis for Marker Compounds

Previous studies have reported that Hedyotis diffusa Willdenow extract shows various biological activities on cerebropathia, such as neuroprotection and short-term memory enhancement. However, there has been a lack of studies on the inhibitory activity on neurodegenerative diseases such as Alzheimer's disease (AD) through enzyme assays of H. diffusa. Therefore, H. diffusa extract and fractions were evaluated for their inhibitory effects through assays of enzymes related to AD, including acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), and β-site amyloid precursor protein cleaving enzyme 1 (BACE1), and on the formation of advanced glycation end-product (AGE). In this study, ten bioactive compounds, including nine iridoid glycosides 1-9 and one flavonol glycoside 10, were isolated from the ethyl acetate and n-butanol fractions of H. diffusa using a bioassay-guided approach. Compound 10 was the strongest inhibitor of cholinesterase, BACE1, and the formation of AGEs of all isolated compounds, while compound 5 had the lowest inhibitory activity. Compounds 3, 6, and 9 exhibited better inhibitory activity than other compounds on AChE, and two pairs of diastereomeric iridoid glycoside structures (compounds 4, 8, and 6, 7) showed higher inhibitory activity than others on BChE. In the BACE1 inhibitory assay, compounds 1-3 were good inhibitors, and compound 10 showed higher inhibitory activity than quercetin, the positive control. Moreover, compounds 1 and 3 were stronger inhibitors of the formation of AGE than aminoguanidine (AMG), the positive control. In conclusion, this study is significant since it demonstrated that the potential inhibitory activity of H. diffusa on enzymes related to AD and showed the potential use for further study as a natural medicine for AD treatment on the basis of the bioactive components isolated from H. diffusa.

Optimisation for simultaneous determination of iridoid glycosides and oligosaccharides in Radix Rehmannia by microwave assisted extraction and HILIC-UHPLC-TQ-MS/MS

Hydrophilic iridoid glycosides and oligosaccharides are the major active ingredients of Radix Rehmanniae. Analysis of oligosaccharides is a challenging task because they are highly hydrophilic, with similar chemical structures and absence of chromophore and fluorophore groups. The difficulty for simultaneous analysis of iridoid glycosides and oligosaccharides in Radix Rehmanniae is increased due to the polarity difference between the two types of ingredients.

OBJECTIVE

To develop a method for simultaneous determination of iridoid glycosides (ajugol, catalpol) and oligosaccharides (sucrose, melibiose, raffinose, mannotriose and stachyose) in Radix Rehmanniae.

METHODOLOGY

Microwave-assisted extraction (MAE) was established to extract target analytes from Radix Rehmanniae samples using methanol-water (60:40, v/v) as the extraction solvent. Fast separation of seven analytes was achieved by hydrophilic interaction liquid chromatography (HILIC) using an Accucore-150-Amide-HILIC column. Sensitive and selective detection of the analytes was performed by triple quadrupole tandem mass spectrometry (TQ-MS/MS) using multiple reaction monitoring in positive electrospray ionisation mode.

RESULTS

Good linearities were achieved for all the analytes with the correlation coefficients above 0.9991. The precisions resulted in deviations of less than 5.0% and the recoveries ranged from 93.8% to 105.5%. The established method was successfully applied to the analysis of iridoid glycosides and oligosaccharides in 12 samples of crude and processed Radix Rehmanniae.

CONCLUSION

A simple, rapid and sensitive method based on MAE combined with HILIC-UHPLC-TQ-MS/MS was developed for simultaneous determination of iridoid glycosides and oligosaccharides in Radix Rehmanniae for the first time. The method exhibited excellent performance with simple sample preparation, short analysis time, high selectivity and sensitivity.

Two new iridoid glycosides from Callicarpa nudiflora

Two new iridoid glycosides, callicoside E (1) and callicoside F (2), were isolated from the leaves of Callicarpa nudiflora. Their structures were established by one- and two-dimensional NMR spectroscopy and mass spectrometry. In an in vitro bioassay, compounds 1 and 2 showed an pronounced hepatoprotective activity against d-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.[Formula: see text].

Iridoids and Amino Acid Derivatives from the Paraguayan Crude Drug Adenocalymma marginatum (ysypó hû)

The crude drug ysypó hû (Adenocalymma marginatum DC., Bignoniaceae) is used traditionally by the Guarani of Eastern Paraguayan as a male sexual enhancer. The aim of the present study was to identify the main constituents of the crude drug and to evaluate the in vitro inhibitory activity towards the enzyme phosphodiesterase-5 (PDE-5). The main compounds were isolated by counter-current chromatography (CCC). The metabolites were identified by spectroscopic and spectrometric means. The chemical profiling of the extracts was assessed by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS/MS). The crude extract and main isolated compounds were tested for their PDE-5 inhibitory activity using commercial kits. The iridoid theviridoside and 4-hydroxy-1-methylproline were isolated as the main constituent of the crude drug. Four chlortheviridoside hexoside derivatives were detected for the first time as natural products. Chemical profiling by HPLC-MS/MS led to the tentative identification of nine iridoids, six phenolics, and five amino acids. The crude extracts and main compounds were inactive towards PDE-5 at concentrations up to 500 µg/mL. Iridoids and amino acid derivatives were the main compounds occurring in the Paraguayan crude drug. The potential of ysypó hû as a male sexual enhancer cannot be discarded, since other mechanisms may be involved.

[Qualitative and quantitative analysis on non-triterpenoids in Ligustri Lucidi Fructus]

In order to improve the quality control level of Ligustri Lucidi Fructus(LLF) and to explore the changes of chemical components after processing,the HPLC method for fingerprint and simultaneous determination of the major polar components in LLF were established. The octadecylsilane bonded silica gel was used as the stationary phase,with acetonitrile as the mobile phase A and0. 2% formic acid as the mobile phase B in a gradient elution procedure at a flow rate of 1. 0 m L·min-1. The detection wavelength was set at 280 nm and the column temperature was 25 ℃. There were 22 common peaks,20 of which were selected from the fingerprint of LLF and its wine-steamed product,respectively,and 14 chromatographic peaks were identified with reference substances. With the same chromatographic conditions,seven components were quantitatively analyzed and the results of system adaptability and methodology investigation all met the requirements of content determination. Compared with the crude LLF,the content of 5-hydroxymethyl furfural and salidroside significantly increased in wine-steamed LLF,while the contents of iridoid glycosides generally decreased. The method provided a basis for quality control of LLF and its processed products as well as the related preparations.

Species-specific plant-soil feedbacks alter herbivore-induced gene expression and defense chemistry in Plantago lanceolata

Plants actively interact with antagonists and beneficial organisms occurring in the above- and belowground domains of terrestrial ecosystems. In the past decade, studies have focused on the role of plant-soil feedbacks (PSF) in a broad range of ecological processes. However, PSF and its legacy effects on plant defense traits, such as induction of defense-related genes and production of defensive secondary metabolites, have not received much attention. Here, we study soil legacy effects created by twelve common grassland plant species on the induction of four defense-related genes, involved in jasmonic acid signaling, related to chewing herbivore defense (LOX2, PPO7), and in salicylic acid signaling, related to pathogen defense (PR1 and PR2) in Plantago lanceolata in response to aboveground herbivory by Mamestra brassicae. We also assessed soil legacy and herbivory effects on the production of terpenoid defense compounds (the iridoid glycosides aucubin and catalpol) in P. lanceolata. Our results show that both soil legacy and herbivory influence phenotypes of P. lanceolata in terms of induction of Pl PPO7 and Pl LOX2, whereas the expression of Pl PR1 and Pl PR2-1 is not affected by soil legacies, nor by herbivory. We also find species-specific soil legacy effects on the production of aucubin. Moreover, P. lanceolata accumulates more catalpol when they are grown in soils conditioned by grass species. Our study highlights that PSF can influence aboveground plant-insect interactions through the impacts on plant defense traits and suggests that aboveground plant defense responses can be determined, at least partly, by plant-specific legacy effects induced by belowground organisms.

A Novel Use of Genipin-Fixed Gelatin as Extracellular Matrix for Peripheral Nerve Regeneration

Application of combining herbal medicine and biomedical material science to nerve regeneration is a new approach. In this study, we describe a novel use of purified genipin, which can be extracted from Gardenia jasminoides Ellis, fixing the gelatin to be an extracellular matrix for peripheral nerve regeneration. A 10-mm gap of rat sciatic nerve was created between the proximal and distal nerve stumps, which were sutured into silicone rubber tubes filled with either the genipin-fixed gelatin or collagen gel. Silicone rubber tubes filled with saline were used as controls. Six weeks after implantation, regeneration across the nerve gaps occurred in 80 and 90% of the animals from the groups of genipin-fixed gelatin and collagen, respectively, whereas only 30% in the control group. Large numbers of myelinated axons were also seen in the genipin-fixed gelatin (5104±3278) and the collagen groups (8063±1807). These findings indicated that the genipin-fixed gelatin could be an acceptable extracellular matrix for nerve regeneration.

[HPLC Analyzed the Iridoid Glycosides of Qingyedan Commonly Used in Folk Medicine in Yunnan]

OBJECTIVE

To compare the contents of iridoid glycosides in Qingyedan medicinal materials,and to provide the scientific basis for using resources of Qingyedan and rationality of original plant medicinal.

METHODS

The contens of three iridoid glycosides,including swertiamarin,gentiopicroside and sweroside in Qingyedan medicinal materials were determined by HPLC.

RESULTS

The constituents of 30 samples in nine species were significant difference. And the contents of iridoid glycosides in Swertia bimaculata,Swertia tenuis and Swertia pubescens were reported for the first time.

CONCLUSION

The results show that the contents of iridoid glycosides in Qingyedan medicinal materials have a significant difference due to the different species and producing areas. Therefore, these medicinal plants should not be used as alternative medicines for clinical application. Swertiamarin and sweroside can be selected as quality control components, this method is an effective method to identify and control the quality of Qingyedan materials.

Influence of cross-linking degree of a biodegradable genipin-cross-linked gelatin guide on peripheral nerve regeneration

We evaluated peripheral nerve regeneration using biodegradable genipin-cross-linked gelatin nerve conduits (GGCs) with three different cross-linking degrees, 24, 36 and 51%. Biocompatibility and biodegradability of the GGC and its efficiency as a guidance channel were examined based on the repair process of a 10-mm gap in the rat sciatic nerve. From this pilot study we concluded that GGCs with a mean cross-linking degree of 36% can ensure nerve regeneration with a more mature structure, as demonstrated by better developed epineural and perineural organisation and axonal development, as well as better-recovered electrophysiology with a relatively positive sciatic functional index and a shorter latency of the muscle action potential curve. Regenerated nerves in the GGCs with mean cross-linking degrees of 24 and 51% were less favourable, due to irritation caused by degradation material and compression by the remaining tube walls, respectively.

pH-sensitive behavior of two-component hydrogels composed of N,O-carboxymethyl chitosan and alginate

A two-component pH-sensitive hydrogel system composed of a water-soluble chitosan derivative (N,O-carboxymethyl chitosan, NOCC) and alginate cross-linked by genipin, glutaraldehyde or Ca2+ was investigated. Preparation and structures of these hydrogels and their swelling characteristics and release profiles of a model protein drug (bovine serum albumin, BSA) in simulated gastrointestinal media are reported. At pH 1.2, the swelling ratios of the hydrogels cross-linked by distinct methods were limited. Of note is that the lowest swelling ratios of test hydrogels were found at pH 4.0. At pH 7.4, the carboxylic acid groups on test hydrogels became progressively ionized and led to a significant swelling. There was barely any BSA released from the glutaraldehyde-cross-linked hydrogel throughout the entire course of the study. The amounts of BSA released at pH 1.2 from the genipin- and Ca(2+)-cross-linked hydrogels were relatively low (approx. 20%). At pH 4.0, there was still significant BSA release from the Ca(2+)-cross-linked hydrogel, while the cumulative BSA released from the genipin-cross-linked hydrogel was limited due to its shrinking behavior. At pH 7.4, the amount of BSA released from the genipin- and Ca(2+)-cross-linked hydrogels increased significantly (approx. 80%) because the swelling of both test hydrogels increased considerably. The aforementioned results indicated that the swelling behaviors and drug-release profiles of these test hydrogels are significantly different due to their distinct cross-linking structures.

[Determination of harpagide and harpagoside in Scrophulariae Radix by HPLC-UV]

OBJECTIVE

To develop a method for the determination of harpagide and harpagoside in Scrophulariae Radix (Xuanshen) by HPLC-UV under double wavelength, and to study the changes of these two constituents during processing, and to set the limitation of harpagide and harpagoside contents in crude drug and sliced pieces of Xuanshen.

METHOD

The analyses were performed on an Agilent Technologies ZORBAX SB-C18 (4.6 mm x 250 mm, 5 microm) eluted with acetonitrile-water (containing 0.03% phosphoric acid) in gradient model. The flow rate was 1.0 mL x min(-1) . The column temperature was 25 degrees C. The UV detector wavelength was set at 210 nm before 13 min and then changed to 280 nm.

RESULT

Harpagide and harpagoside were separated well. The linear calibration curves were obtained over of 0.0549 - 1.46 microg for harpagide (r = 0.9999, n =7) ,0.0225 - 0.900 microg for harpagoside (r = 0.9998, n = 9). The recoveries ( +/- RSD)% were 98.1 (+/- 2.4)% for harpagide and 98.8 (+/- 4.3)% for harpagoside. The contents of harpagide were 0. 277% - 0.620%, harpagoside were 0.078% - 0.362% in Xuanshen, and harpagide were 0.276% - 1.059%, harpagoside were 0. 059% - 0.183% in sliced Xuanshen, respectively. After the processing of Scrophulariae Radix, the content of harpagide increases 13.7% - 96.0%, while harpagoside decreases 11.0%-73.9%.

CONCLUSION

This method is simple, accurate, and can be used for the quality control of Scrophulariae Radix. We propose that the total content of harpagide and harpagoside in either crude drug or sliced pieces of Scrophulariae Radix should not be less than 0.45%.

[Simultaneous determination of five constituents in Scrophularia ningpoensis by HPLC]

OBJECTIVE

To develop an HPLC method for the simultaneous quantitation of five constituents in Scrophularia ningpoensis.

METHOD

Samples were analyzed on an Agilent SB-C18 column(4.6 mm x 250 mm, 5 microm) eluted with acetonitrile and water containing 0.03% phosphate acid as mobile phases in a linear gradient mode. The flow rate was kept at 1.0 mL x min(-1), and the column temperature was set to 30 degrees C. The DAD detector wavelengths were 210, 280, 330 nm.

RESULT

The linear ranges were 50-400 mg x L(-1) for harpagide, 1-40 mg x L(-1) for harpagoside, 1-20 mg x L(-1) for cinnamic acid, 0.5-4.5 mg x L(-1) for acteoside,1-60 mg x L(-1) for angoroside C, respectively. The average recoveries of the five constituents were 100.8% (RSD 0.62%), 101.7% (RSD 0.32%), 98.8% (RSD 0.48%), 99.9% (RSD 1.4%), 99.2% (RSD 1.1%), respectively.

CONCLUSION

Through the validation, the method was proved to be sensitive, accurate, repeatable, and can be used for quality control of the roots of S. ningpoensis.

Anti-inflammatory effect of Ajuga bracteosa Wall Ex Benth. mediated through cyclooxygenase (COX) inhibition

ETHNOPHARMACOLOGICAL RELEVANCE

Ajuga bracteosa Wall Ex Benth. (Labiateae) is described in Ayurveda for the treatment of rheumatism, gout, palsy and amenorrhea.

AIM OF THE STUDY

The aim of present investigation is to study anti-inflammatory activity of Ajuga bracteosa, to understand possible mechanism of action and to identify the constituents responsible for its activity.

MATERIALS AND METHODS

The anti-inflammatory activity of 70% ethanolic extract was evaluated in TPA-induced mouse ear edema assay and in vitro cyclooxygenase (COX)-1 and COX-2 inhibitory activity was determined using EIA kits employing appropriate reference standards. Aajugarin I, lupulin A, withaferin A, reptoside and 6-deoxyharpagide were isolated from the 70% ethanolic extract by silica gel column chromatography.

RESULTS

The 70% ethanol extract of whole plants of Ajuga bracteosa showed a significant (p<0.05) and dose-dependent anti-inflammatory activity in an acute inflammation model at the dose of 0.5 and 1.0 mg/ear. The extract also exhibited a strong in vitro COX-1 and COX-2 inhibitory activity at 25 and 50 μg/mL concentration. Among the isolated compounds 6-deoxyharpagide exhibited highest COX-2 inhibition while rest of the compounds exhibited weak to moderate COX-1 and COX-2 inhibition at 30 μM concentration.

CONCLUSIONS

The results suggest that the 70% ethanol extract of Ajuga bracteosa possesses promising anti-inflammatory activity, which is possibly mediated through inhibition of COX-1 and COX-2 enzymes. The isolated constituents could be responsible in part for its anti-inflammatory and COX inhibitory activity. The study supports traditional use of Ajuga bracteosa for inflammatory diseases.

Iridoid glycosides from Saprosma ternatum

Three new iridoid glycosides, epiasperuloside (1), epipaederosidic acid (2), and epipaederoside (3), together with 7 known compounds, were isolated from the 85% ethanol extract of the leaves of Saprosma ternatum Hook. f. Their structures were determined by application of spectroscopic (NMR, MS) and chemical methodologies. The antioxidant activity was evaluated for all isolates in terms of both DPPH and ABTS bioassays. Epiasperuloside (1) showed some antioxidant activity.

Two new secoiridoid glycosides from Verbena officinalis

Two new secoiridoid glycosides, verbenoside A (1) and verbenoside B (2), have been isolated from the ethanol extract of the aerial parts of Verbena officinalis L. Their structures were elucidated on the basis of spectroscopic evidences, especially 1D, 2D NMR, and MS experiments.

Two new dimeric secoiridoid glycosides from the fruits of Ligustrum lucidum

Two new secoiridoid glycosides, ligusides A and B (1 and 2), as well as seven known compounds (3-9), were isolated from the fruits of Ligustrum lucidum. Their structures were elucidated on the basis of spectroscopic and chemical analysis.

Three new secoiridoid glycoside dimers from Swertia mileensis

Three new secoiridoid glycoside dimers named swerilactosides A-C (1-3) were isolated from Swertia mileensis. Their structures were elucidated based on extensive spectral analyses (1D and 2D NMR, MS, and IR spectroscopic means).

Investigation on magnetically controlled delivery of doxorubicin from superparamagnetic nanocarriers of gelatin crosslinked with genipin

Gelatin (Type B) nanoparticles were prepared by a single W/O emulsion technique and characterized by infrared (IR) spectra, transmission electron micrographs (TEM), surface potential measurements and magnetization studies. Whereas the IR spectra clearly confirmed the presence of gelatin, genipin and doxorubicin in the loaded nanoparticles, the transmission electron micrographs (TEM) image depicts smooth surface, spherical shape and non-uniform size of nanoparticles (up to 100 nm). The prepared nanoparticles were loaded with doxorubicin, a well known anticancer drug, and in vitro release dynamics of entrapped drug was investigated as a function of various experimental factors such as percent loading of the drug, chemical architecture of the nanocarriers, and pH, temperature, ionic strength and nature of the release medium in presence and absence of magnetic field. The nanoparticles were also studied for their water sorption capacity. The drug release process was analyzed kinetically using Ficks power law and a correlation was established between the quantity of released drug and swelling of the nanoparticles.

Kinetic characterization and comparison of various protein crosslinking reagents for matrix modification

We have characterized the relative efficacies of a number of protein crosslinking agents that have the potential for use in the crosslinking of proteinaceous matrices both in vitro and in vivo. The crosslinkers tested were; L: -threose (LT), Genipin (GP), Methylglyoxal (MG), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC), proanthrocyanidin (PA) and glutaraldehyde (GA). The relative effectiveness of the crosslinkers with regard to their saturating concentrations was: GA > PA > EDC > MG = GP >> LT. Most of the crosslinkers displayed a pH dependence and were more effective at more alkaline pH. At optimal pH and saturating conditions, the relative reaction rates of the crosslinkers were: PA = GA > EDC > GP > MG >> LT.

Active ingredients of traditional Japanese (kampo) medicine, inchinkoto, in murine concanavalin A-induced hepatitis

AIM OF THE STUDY

The traditional Japanese (kampo) medicine inchinkoto (ICKT) is used in Eastern Asia as a choleretic and hepatoprotective agent. Previously, we reported that ICKT ameliorates murine concanavalin A (con A)-induced hepatitis via suppression of interferon (IFN)-gamma and interleukin (IL)-12 production. In the present study, we investigated the active ingredients of ICKT.

MATERIALS AND METHODS

ICKT and extracts of its component herbs were fractionated, and their effects on liver injury and cytokine production in vivo (biochemical markers of liver injury and cytokine levels in serum) and in vitro (cytokine and nitrite production in the cultures of splenocytes and peritoneal macrophages).

RESULTS

Decoctions of component herbs, Artemisiae Capillari Spica (Artemisia capillaris Thunberg: 'Inchinko' in Japanese), Gardeniae Fructus (Gardenia jasminoides Ellis: 'Sanshishi') and Rhei Rhizoma (Rheum palmatum Linné: 'Daio') were administered orally. Inchinko and Sanshishi decreased serum transaminases and IFN-gamma concentrations. Examination of fractions of component herbs suggested that capillarisin, a component of Inchinko, has potent hepatoprotective activity in vivo. In in vitro studies, capillarisin and genipin, an intestinal metabolite of geniposide that is contained in Sanshishi, were examined. IFN-gamma production was significantly suppressed by capillarisin and genipin in con A-stimulated splenocyte culture. Genipin also suppressed IL-1beta, IL-6, and IL-12p70 synthesis. Capillarisin and genipin decreased nitrite release from IFN-gamma-stimulated macrophages.

CONCLUSIONS

These results suggested that both Inchinko and Sanshishi may contribute to the protective effects of ICKT against con A hepatitis. Capillarisin was found to be potently hepatoprotective, and genipin may also contribute, especially via modulation of cytokine production.

In vitro study in the endothelial cell compatibility and endothelialization of genipin-crosslinked biological tissues for tissue-engineered vascular scaffolds

To overcome the cytotoxicity of the chemical reagents used to fix bioprostheses, genipin, a naturally occurring crosslinking agent, was used to fix biological tissues in present study. We prepared the biological vascular scaffolds through cell extraction and fixing the porcine thoracic arteries with 1% (by w/v) genipin solution for 3 days, and then examined their mechanical properties and microstructures; glutaraldehyde- and epoxy-fixed counterparts were used as controls. HUVECs were seeded on the type I collagen-coated surface of different modified acellular vascular tissues (fixed with different crosslinking agents), and the growths of HUVECs on the specimens were demonstrated by means of MTT test, the secretion of PGI2 and vWF by HUVECs on the various specimens was also measured. Finally, HUVECs were seeded on the luminal surface of acellular biological vascular scaffolds (<6 mm internal diameter) which were, respectively, treated in the same manner described above, and then cultured for 9 days. On the ninth day, the HUVECs on the luminal surface of these vascular scaffolds were examined morphologically and by immunohistochemistry. Genipin-fixation can markedly diminish antigenicity of the vascular tissues through partially getting rid of cell or reducing the level of free amino groups in the vascular tissues. Genipin-fixed acellular vascular tissues mimicked the natural vessels due to the maintenance of the integrity of total structure and the large preservation of the microstructures of collagen fibers and elastic fibers; therefore, it appeared suitable to fabricate vascular scaffolds in mechanical properties. Compared to controls, the genipin-fixed acellular vascular tissues were characterized by low cytotoxicity and good cytocompatibility. The HUVECs can not only proliferate well on the genipin-fixed acellular vascular tissues, but also preserve the activities and function of endothelial cells, and easily make it endothelialized in vitro. The results showed that the genipin-fixed acellular porcine vascular scaffolds should be promising materials for fabricating vascular grafts or the scaffolds of tissue-engineered blood vessels.

Iridoids from Fraxinus excelsior with adipocyte differentiation-inhibitory and PPARalpha activation activity

Two new secoiridoid glucosides, excelsides A (1) and B (2), were isolated from the seeds of Fraxinus excelsior. Their structures were elucidated as (2S,4S,3E)-methyl 3-ethylidene-4-(2-methoxy-2-oxoethyl)-2-[(6-O-beta-D-glucopyranosyl-beta-d-glucopyranosyl)oxy]-3,4-dihydro-2H-pyran-5-carboxylate and (2S,4S,3E)-methyl 3-ethylidene-4-{2-[2-(4-hydroxyphenyl)ethyl]oxy-2-oxoethyl}-2-[(6-O-beta-d-glucopyranosyl-beta-d-glucopyranosyl)oxy]-3,4-dihydro-2H-pyran-5-carboxylate, respectively, on the basis of NMR and MS data. Eight known compounds were identified as nuzhenide (3), GI3 (4), GI5 (5), ligstroside (6), oleoside 11-methyl ester (7), oleoside dimethyl ester (8), 1'''-O-beta-D-glucosylformoside (9), and salidroside (10). Compounds 1-9 inhibited adipocyte differentiation in 3T3-L1 cells. Dilutions of the aqueous extract of F. excelsior (1:10,000) as well as compounds 2, 3, 4, 5, and 8 activated the peroxisome proliferator-mediated receptor-alpha (PPARalpha) reporter cell system in the range of 10(-4) M, compared to 10(-7)-10(-8) M for the synthetic PPARalpha activator, WY14,643. Both biological activity profiles support the hypothesis that inhibition of adipocyte differentiation and PPARalpha-mediated mechanisms might be relevant pathways for the antidiabetic activity of F. excelsior extract.

Two new secoiridoid glycosides from the leaves of Olea europaea L

Two new secoiridoid glycosides, oleuricines A (1) and B (2), together with five known triterpenoids, beta-amyrin, oleanolic acid, erythrodiol, urs-2beta,3beta-dihydroxy-12-en-28-oic acid, and beta-maslinic acid, were isolated from the EtOAc-soluble part of EtOH extract of the leaves of Olea europaea L. The structures of these compounds were elucidated by various spectroscopic methods, including intensive 1D, 2D NMR, and HR-ESI-MS techniques.

Hemoglobin Polymerized with a Naturally Occurring Crosslinking Agent as a Blood Substitute: In Vitro and In Vivo Studies

A naturally occurring crosslinking agent, genipin, extracted from the fruits of Gardenia jasminoides ELLIS was used by our group to chemically modified biomolecules. Genipin and its related iridoid glucosides have been widely used as an antiphlogistic and cholagogue in herbal medicine. Our previous study showed that the cytotoxicity of genipin is significantly lower than glutaraldehyde. The study was to investigate the feasibility of using genipin to polymerize hemoglobin as a blood substitute. The results indicated that the rate of hemoglobin polymerization by glutaraldehyde was significantly faster than that by genipin and it readily produced polymers with molecular masses greater than 500,000 Da. It was found that the maximum degree of hemoglobin polymerization by genipin was approximately 40% if over-polymerization is to be prevented. With increasing the reaction temperature, hemoglobin concentration, and genipin-to-hemoglobin molar ratio, the duration taken to achieve the maximum degree of hemoglobin polymerization by genipin became significantly shorter. The P50 value of the unmodified hemoglobin was 9 mmHg, while that of the genipin-polymerized PLP-hemoglobin increased to 21 mmHg. It was found in a rat model that the genipin-polymerized PLP-hemoglobin resulted in a longer circulation time than the unmodified hemoglobin. In conclusion, the results of the study indicated that the genipin-polymerized hemoglobin solution has a lower oxygen affinity and a longer vascular retention time than the unmodified hemoglobin solution.

Gardenia jasminoides Ellis ethanol extract and its constituents reduce the risks of gastritis and reverse gastric lesions in rats

In this study we investigated the effects of Gardenia jasminoides Ellis (GJE) extract and its constituents, such as ursolic acid and genipin, on gastritis in rats and the growth of human gastric cancer cells. The GJE extract, ursolic acid and genipin showed the acid-neutralizing capacities, the antioxidant activities, and the inhibitory effects on the growth of Helicobacter pylori (H. pylori), which are almost equivalent to positive control compounds. In addition, the GJE extract and ursolic acid had cytotoxic activity against AGS and SUN638 gastric cancer cells. The genipin and ursolic acid inhibited significant HCl/ethanol-induced gastric lesions. Taken together, GJE extract and its constituents might have antigastritic activities, associated with the antioxidant activities, acid-neutralizing capacities, and anti-H. pylori action. Also, we could suggest that genipin and ursolic acid may be useful for the treatment and/or protection of gastritis.

Creation of macroporous calcium phosphate cements as bone substitutes by using genipin-crosslinked gelatin microspheres

Macroporous calcium phosphate cements (CPCs) were developed using genipin-crosslinked gelatin microspheres (GMs) with two weight ratios (2.5 wt% and 5 wt%). The initial setting time of the composite was prolonged by GMs. After GMs/CPCs were soaked in phosphate-buffered saline (PBS) for several weeks, macropores appeared as a result of the degradation of GMs. The presence of GMs accelerated the setting reaction and improved the structure of the composite. The compressive strength increased up to 12 MPa (2.5 wt% GMs/CPCs) and 14 MPa (5 wt% GMs/CPCs) after one week of PBS soaking, then gradually decreased to 9 MPa (2.5 wt% GMs/CPCs) and 7 MPa (5 wt% GMs/CPCs) after three weeks of soaking, and further to 6 MPa (2.5 wt% GMs/CPCs) and 2 MPa (5 wt% GMs/CPCs) after five weeks of soaking. CPCs with 2.5 wt% GMs were the most favorable composite in the tested samples. Cell experiments showed that rat osteoblasts displayed normal morphologies when exposed to the 2.5 wt% GMs/CPCs, and proliferation of the cells was also enhanced. An in vivo study showed that new bone tissue was able to grow into the pores that resulted from GM degradation. This study suggests that the new composite could be a promising candidate for use as a bone substitute under non-compression-loaded circumstances.

[Characterization and biocompatibility of human-like collagen-hyaluronic acid scaffold for blood vessel]

Human-like collagen (HLC) was cross-linked with hyaluronic acid by genipin in different ratio. The concentrations of hyaluronic acid in the mixture were 0, 0.01%, 0.05% and 0.1%. The blood vessel tubular grafts were then fabricated by freeze-drying. Microstructure, element composite, mechanical properties, cytotoxicity grade, and biocompatibility of different vascular scaffold groups were studied by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), tensile test, burst pressure experiment, cytotoxicity experiment, endothelial cells planted in blood vessel scaffolds and hypodermic embedding of mice. The results showed that HLC-HA (0.05%) tubular scaffold exhibited interconnected well-distributed and porous structure and porosity of 94.38%; achieved the desirable mechanical property with stress of (1000.8 +/- 7.9) kPa and burst pressure of (1058.6 +/- 8.2) kPa, hypocytotoxicity, favourable cytocompatibility, hisocompatibility and disposition of degradation.

[Effect of UCP2 activity inhibitor genipin on heart function of aging rats]

To estimate the role of uncoupling proteins in aging rat heart recovery from prolonged ischemia we used genipin application during Langendorfpreparation. It was shown that genipin in dose-depended manner depressed coronary flow, heart rate and cardiac diastolic function. Such effect was similar to that observed during myocardial Ca2+ overload by gradually elevated CaCl2, in perfusion solution. Moreover, postischemic disturbances of cardiodynamic parameters, oxygen cost of myocardial work were much increased in genipin pretreated hearts that in control ones. Thus, genipin inhibition of UCP2 activity has cardiodepressive effects that imply UCPs in cardiac calcium regulation.

[Effects of uncoupling proteins on nitric oxide synthesis and oxidative stress development in ishemia-reperfusion of old rat hearts]

Genipin is aglycone of geniposide, one of the active compounds of Gardenia gasminoides Ellis. The gardenia fruit extract has been used in traditional Chinese medicine to relieve the symptoms of type 2 diabetes that is accompanied with extensive oxidative stress and endothelial dysfunction of NO production. Besides, genipin was shown to inhibit UCP-depended proton leak through the inner mitochondrial membrane that leads to increased membrane potential and ATP production. We studied the effects of genipin at ischemia/reperfusion-induced oxidative stress and activity of NOS isozymes using Langendorfperfused old rat heart model. Ischemia/reperfusion is well-known oxidative agent, and showed significant increasing of superoxide radical, hydrogen peroxide and hydroxyl radical. Genipin application in doze 10-5 mol/L for 15 min before prolonged ischemia exerted powerful antiradical and antilipoperoxidative effects. Heart ischemia/reperfusion was supported with peroxynitrite generation and nitrozative stress. We demonstrated the inhibitory property of genipin on INOS expression that possibly occurs via protein kinase A inhibition and stabilization of I-kappaB-NF-kappaB complex. Genipin stimulated cNOS activity seemingly activating PI3K/Akt signaling pathway. Although, post-ischemic recovery ofcardiodynamic parameters of old rat hearts were depressed due to "switching off" the NO production by inducible NOS which is important in early period of reperfusion. Thus, we conclude that genipin is powerfull antioxidant and posses insulin-like activity due to its property of managing the NO production at intracellular signal transduction cascade level.

[Comparison of characteristics between glutaraldehyde- and genipin-crosslinked gelatin microspheres]

OBJECTIVE

To compare the characteristics of gelatin microspheres crosslinked by glutaraldehyde (GA) or genipin (GP).

METHODS

Gelatin microspheres, prepared by the improved emulsified cold-condensation method, were crosslinked by GP and GA, respectively. After being dispersed in PBS, two kinds of microspheres with 60% degree of cross linking were compared in terms of morphology, swelling and degrading properties. rhBMP-2 were loaded into the GP and GA microspheres, and the encapsulation rate, drug loading and releasing capacity were measured; 100%, 50% and 25% leaching liquid of GP and GA microspheres were respectively cultured with rat osteoblast (DMEM group as the control), and cell proliferation was measured by MTT method to grade the cell cytotoxicity.

RESULTS

GP and GA microspheres were both spherical with the diameters of (78 +/- 18) microm and (65 +/- 10) microm, and there were no difference between both microspheres in drug loading and encapsulation rate. But, GP microspheres, with long degrading period (28 days) compared to GA microspheres (21 days), had better dispersibility, and swelling rate (89.0% +/- 4.8%), the percentage of cumulative drug releasing at 10 days (78.80% +/- 4.96%) were both lower than GA microsphere (118.0% +/- 7.6%, 90.50% +/- 5.12%). The percentages of drug loading of GP and GA were (921 +/- 73) and (965 +/- 62) ng/g, and the encapsulation rates were 88.5% +/- 2.1% and 89.7% +/- 1.8%; showing no significant difference (P > 0.05). The cell cytotoxicity of 100%, 50% and 25% leaching liquid of GP microspheres was all at the level I, but leaching liquid of GA microspheres with corresponding concentration were at the levels of III, III and II.

CONCLUSION

GP crosslinked gelatin microspheres are superior to GA crosslinked gelatin microspheres and can be widely used in tissue engineering field.

Genipin blues: an alternative non-toxic crosslinker for heart valves?

BACKGROUND AND AIM OF THE STUDY

One approach in tissue-engineering involves the implantation of decellularized, xenogenic scaffolds, with the expectation of repopulation in vivo. However, a major limitation of this method is the propensity to induce a strong immune host response. The study aim was to mitigate this immunogenicity by employing a crosslinking treatment with genipin.

METHODS

Porcine matrices were prepared using a detergent-enzymatic treatment and fixed in 0.01% or 0.001% aqueous genipin. The mechanical properties of the matrices were monitored by tensile strength testing. The survival of chicken fibroblasts was used to determine cell-friendliness of the matrices. Non-fixed, decellularized biological scaffolds (n = 3) were implanted in a sheep model and compared to an equal number of genipin-fixed scaffolds (n = 6). Matrices implanted in the pulmonary position were explanted after six weeks and examined using light and transmission electron microscopy. The antibody reaction against porcine tissue in sheep serum was also determined.

RESULTS

Statistically significant differences were found between non-fixed leaflets, 0.001% genipin-and 0.6% glutaraldehyde (GA)-fixed leaflets for work to maximum load (non-fixed 0.00646 J; genipin-fixed 0.00509 J; GA-fixed 0.00543 J) and stiffness (non-fixed 9281 N/m; genipin-fixed 16214 N/m; GA-fixed 14401 N/m). Genipin-treated matrices were not cytotoxic. For all concentrations of genipin a high proportion of viable cells was present (79-100%). Low-dose GA (10 microg/ml) showed a distinct cytotoxicity (24.8% viability). At explant, an intense chronic inflammatory response was observed in non-fixed matrices, in contrast to genipin-fixed scaffolds. The sheep serum showed a marked decrease in IgG response in both 0.001% and 0.01% genipin-fixed matrices (IgG 30 and 20, respectively) when compared to non-fixed matrices (IgG 40).

CONCLUSION

Genipin crosslinking of the matrices attenuated, but did not eliminate, the inflammatory host reaction. Whether genipin treatment might extend the durability of xenogenic scaffolds remains to be investigated.

Effect of process variables on particle size and viability ofBifidobacterium lactisBb-12 in genipin-gelatin microspheres

Gelatin microspheres cross-linked with genipin were developed to encapsulate the probiotic Bifidobacterium lactis Bb-12 The effects of different gelatin concentrations (10-19% w/v), bloom strengths (175 and 300), surfactants, stirring rates during emulsion formation and genipin concentrations (0-10 mM) on the microsphere sizes and viability of bacterial cells were investigated. Principal Component Analysis revealed microsphere size distribution differed depending on the presence or absence of surfactants as well as a trend of increasing micropshere size with increasing gelatin concentration and bloom strength. Lower stirring rates resulted in larger microspheres with higher encapsulation yields of bifidobacteria Microsphere size and cell viability were not significantly (p < 0.05) influenced by increasing genipin concentrations up to 10 mM whereas microsphere stability in simulated gastric juice increased with increasing genipin concentration. The encapsulation yields were higher in 175 bloom strength gelatin microspheres than in 300. Cold-stage scanning electron microscopy showed encapsulated bacteria distributed throughout the genipin cross-linked gelatin matrix.