Cortex Dictamni Research Articles

Sub-chronic toxicity of the active fraction of a modified Huang-Lian-Jie-Du Decoction

A traditional Chinese herbal medicine formula named Huang-Lian-Jie-Du Decoction (HLJDD) has been used to cure various inflammatory diseases with a long history. However, one component of HLJDD Gardeniae fructus has remarkable liver and kidney toxicities. Therefore, it was altered with Dictamni cortex to form a modified HLJDD (MHLJDD). In this study, we aimed to evaluate the sub-chronic toxicity of the active fraction of MHLJDD (MHLJDD-F) in rats. Adult rats of both sexes were intragastrically administered with vehicle or MHLJDD-F (at the dose of 170, 340, and 680 mg/kg/day) once daily for 90 days. Half of the rats from each group were kept for an additional 30-day period to observe the drug withdrawal effect. The signs of toxicity and mortality of the rats were observed, and the body weight and food consumption were recorded. Blood was collected for hematological and biochemical analyses and major organs were weighed and harvested for histopathological examinations. The results revealed that no systemic toxicity of MHLJDD-F was found during the experiments. Organ coefficients and pathological alterations of major organs were comparable to the control rats. The no-observed adverse effect level (NOAEL) of MHLJDD-F was found up to 680 mg/kg/day. All these results demonstrated that long-term oral administration of MHLJDD-F did not cause significant toxicity, which is worthy to be widely applied as a new herbal medicine in pre-clinical and clinical studies.

Dictamnine Ameliorates DNFB-Induced Atopic Dermatitis Like Skin Lesions in Mice by Inhibiting M1 Macrophage Polarization and Promoting Autophagy.

Autophagy and M1 macrophage polarization play important roles in the regulation of inflammation in atopic dermatitis (AD). Dictamnine is one of the main ingredients in Cortex Dictamni, a widely used traditional Chinese medicine for the treatment of dermatitis. In the present study, we investigated the anti-inflammatory effects of dictamnine on AD like skin lesions and M1 macrophage polarization. A 2,4-dinitrofluorobenzene (DNFB) triggered AD like skin lesions models in mice was established to identify the ameliorative effects of dictamnine on AD in vivo. In addition, an M1 macrophage polarization model was co-stimulated by lipopolysaccharide (LPS) and interferon-γ (IFN-γ) using phorbol myristate acetate (PMA) differentiated THP-1 cells, to investigate the effect of dictamnine on promoting autophagy and inhibiting inflammatory factor release. Dictamnine suppressed DNFB-induced skin inflammation by inhibiting M1 macrophage polarization, up-regulating the expression of microtubule-associated protein 1A/1B-light chain 3 (LC3) expression, and promoting macrophage autophagy at inflammatory sites. Dictamnine also could reduce the release of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), monocyte chemotactic protein-1 (MCP-1), and interleukin-8 (IL-8), and down-regulate the mRNA expression of these genes in LPS-IFN-γ triggered M1 polarized macrophages. Dictamnine ameliorates AD like skin lesions by inhibiting M1 macrophage polarization and promoting autophagy. Hence, dictamnine is expected to be a potential therapeutic candidate for AD.

Research on a data mining algorithm based on BERTopic for medication rules in Traditional Chinese Medicine prescriptions

AbstractBackgroundA data mining algorithm is proposed based on BERTopic to provide new insights into the analysis of medication rules in Traditional Chinese Medicine (TCM) prescriptions.MethodsUsing the BERTopic algorithm, collected TCM prescriptions for corneal diseases are converted to embeddings through a transformer based on the Bidirectional Encoder Representations from Transformers pre‐trained model. Then, Uniform Manifold Approximation and Projection is applied to perform dimensionality reduction in prescription embeddings. Subsequently, Hierarchical Density‐Based Spatial Clustering of Applications with Noise is used for clustering. Finally, class‐based term frequency–inverse document frequency is used to generate several main drug combinations from the clustered results.ResultsThe highest frequency of drugs used included Buddleja officinalis, Bidens pilosa, Angelica sinensis, Eriocaulon buergerianum, and Raw Rehmannia glutinosa. The most frequent drug combinations were “Eriocaulon buergerianum, Raw Rehmannia glutinosa, Prunella vulgaris, Notopterygium incisum” “Lycii Fructus, Bidens pilosa, Buddleja officinalis” and “Kochiae Fructus, Cortex Dictamni.”ConclusionsThe proposed data mining algorithm based on BERTopic demonstrated promising outcomes in the analysis of TCM prescription medication rules. This method exhibited simplicity and efficiency, thereby offering a novel avenue for analysis.

A rapid and eco-friendly method for determination of dictamnine, obacunone, and fraxinellone in Cortex Dictamni by LC–MS and matrix solid-phase dispersion extraction

This study develops a rapid and eco-friendly liquid chromatography–mass spectrometry method for determining dictamnine, obacunone, and fraxinellone in Cortex Dictamni. The samples were extracted by matrix solid-phase dispersion extraction with ethanol. The liquid chromatography separation was operated on an Agilent InfinityLab Poroshell 120 EC-C18 column (2.1 mm × 30 mm, 2.7 μm) using 45% ethanol at a 0.3 mL/min flow rate. Mass spectrometry detection was set at positive ion mode, and the selected ion monitoring mode was used to record the target compounds: dictamnine (mass-to-charge ratio 200), obacunone (mass-to-charge ratio 455), and fraxinellone (mass-to-charge ratio 233). The calibration curves exhibited good linearity (R > 0.9994) within the test range. The intra-day precision was 0.601% for dictamnine, 1.03% for obacunone, and 0.898% for fraxinellone. The recoveries were 100% for dictamnine, 101% for obacunone, and 96.2% for fraxinellone. Six samples were analyzed, and they all conformed to the content requirements of the Chinese Pharmacopeia. Notably, the developed method only requires 6.07 mL ethanol and costs 12 min. This study presents a rapid and eco-friendly analytical method for determining three components in Cortex Dictamni, which will help improve the quality evaluation technology of Cortex Dictamni.

Protection of schisantherin A against dictamnine-induced hepatotoxicity: Pharmacokinetic insights.

Dictamnine (DIC), as the most abundant furoquinoline alkaloid ingredient of the herbal medicine Cortex Dictamni (CD), can induce severe liver injury. A previous study found that DIC-induced liver injury was initiated by cytochrome P4503A (CYP3A)-mediated metabolic activation and subsequent formation of adducts with cellular proteins. Schisantherin A (SchA) is the major lignan component of the herbal medicine Schisandra chinensis (SC). SC is frequently combined with CD used in numerous Chinese medicinal formulas for the treatment of eczema and urticaria. Furthermore, SC could protect against CD-induced hepatotoxicity. The objective of the study was to investigate the protective effect of SchA on DIC-induced hepatotoxicity based on pharmacokinetic interactions. The studies found that SchA exerted a protective effect on DIC-induced hepatotoxicity in a dose-dependent manner. Pharmacokinetic studies showed that pretreatment with SchA enhanced the area under concentration-time curve(AUC) and maximal concentration (Cmax ) values of DIC in the serum and liver tissue of mice, indicating that SchA could augment the accumulation of DIC in the circulation. In vitro metabolism assays with mouse liver microsomes (MLMs) showed that SchA reduced the production of DIC-glutathione (GSH) conjugate. In addition, SchA significantly reduced the excretion of DIC-GSH conjugate in the urine of mice and relieved hepatic GSH depletion induced by DIC. These results suggested that SchA could inhibit the metabolic activation of DIC in vitro and in vivo. In summary, our findings showed that the observed pharmacokinetic interactions might be attributable to the inhibition of the metabolism of DIC by SchA, which might be responsible for the protection of SchA against DIC-induced hepatotoxicity. Therefore, the development of a standardized combination of DIC and SchA may protect patients from DIC-induced liver injury.

Isomaculosidine facilitates NLRP3 inflammasome activation by promoting mitochondrial reactive oxygen species production and causes idiosyncratic liver injury

Ethnopharmacological relevanceDictamnus dasycarpus Turcz. (Dictamni Cortex, DC), a Chinese herbal medicine, is commonly used for treating chronic dermatosis and rheumatism, but can also cause herb-induced liver injury (HILI). Our study has demonstrated that DC can induce idiosyncratic HILI, but the mechanism remains unknown. The NLRP3 inflammasome has become a major target for addressing many diseases. The activation of NLRP3 inflammasome is responsible for many liver-related inflammatory diseases, including idiosyncratic HILI. Aim of the studyThe objective of our study was to demonstrate the mechanism underlying the idiosyncratic HILI induced by DC and clarify the susceptible component in DC. Materials and methodsBone marrow-derived macrophages (BMDMs) and THP1 cells were selected to assess the effect of isomaculosidine (IMD) on NLRP3 inflammasome activation in vitro. Western blot, ELISA and Caspase-Glo® 1 Inflammasome Assay, flow cytometry and Immunofluorescence were employed to detect the mechanism of IMD on NLRP3 inflammasome activation. To assess the efficacy of IMD in vivo, mice were intravenously administrated with LPS and then IMD were injected intraperitoneally for 6 h. ResultsThe results of our in vitro studies demonstrate that IMD, the major constituent of DC, specifically promoted ATP- and nigericin-induced activation of NLRP3 inflammasome, but not NLRC4 and AIM2 inflammasomes. Additionally, IMD promoted nigericin-induced ASC oligomerization. Notably, synergistic induction of mtROS played a key role on the activation of NLRP3 inflammasome. IMD increased the mtROS production in the activation of NLRP3 inflammasome induced by nigericin. In addition, the results of our in vivo study showed that the combination of nonhepatotoxic doses of LPS and IMD can increase the levels of ALT, AST, and DBIL, leading to liver injury. ConclusionsIMD specifically facilitated the activation of NLRP3 inflammasome induced by nigericin and ATP, which is responsible for DC-induced idiosyncratic HILI.

Exploring the Mechanism of Hepatotoxicity Induced by Dictamnus dasycarpus Based on Network Pharmacology, Molecular Docking and Experimental Pharmacology.

The root bark of Dictamnus dasycarpus Turcz is a traditional Chinese medicine, Dictamni Cortex (DC), which is mainly used in the clinical treatment of skin inflammation, eczema, rubella, rheumatism, and gynecological inflammation. Unexpectedly, there are some cases of liver injury after the administration of DC. However, the mechanism of hepatotoxicity remains ambiguous. The aim of this study was to explore the mechanism and substance bases of DC hepatotoxicity based on network pharmacology and molecular docking, verified through pharmacological experiments. Partial prototype components and metabolites in vivo of quinoline alkaloids from DC were selected as candidate compounds, whose targets were collected from databases. Network pharmacology was applied to study the potential hepatotoxic mechanism after correlating the targets of candidate compounds with the targets of hepatotoxicity. Molecular docking was simulated to uncover the molecular mechanism. Furthermore, the hepatotoxicity of the extract and its constituents from DC was evaluated in vivo and in vitro. We constructed the "potential toxic components-toxic target-toxic pathway" network. Our results showed that the targets of DC included CYP1A2 and GSR, participating in heterologous steroid metabolism, REDOX metabolism, drug metabolism, heterocyclic metabolic processes, the synthesis of steroid hormone, cytochrome P450 metabolism, chemical carcinogens and bile secretion pathways. In vitro and in vivo experiments displayed that DC could result in a decrease in GSH-Px and oxidative stress, simultaneously inhibiting the expression of CYP1A2 and inducing hepatotoxicity. These results further indicated the mechanism of hepatotoxicity induced by Dictamnus dasycarpus, providing a basic theory to explore and prevent hepatotoxicity in the clinical usage of Dictamnus dasycarpus.

Difference in liver injury induced by dictamnine between males and females: based on untargeted metabolomics

In recent years, reports of adverse reactions related to traditional Chinese medicine(TCM) have been on the rise, especially some traditionally considered "non-toxic" TCM(such as Dictamni Cortex). This has aroused the concern of scholars. This study aims to explore the metabolomic mechanism underlying the difference in liver injury induced by dictamnine between males and females through the experiment on 4-week-old mice. The results showed that the serum biochemical indexes of liver function and organ coefficients were significantly increased by dictamnine(P<0.05), and hepatic alveolar steatosis was mainly observed in female mice. However, no histopathological changes were observed in the male mice. Furthermore, a total of 48 differential metabolites(such as tryptophan, corticosterone, and indole) related to the difference in liver injury between males and females were screened out by untargeted metabolomics and multivariate statistical analysis. According to the receiver operating characteristic(ROC) curve, 14 metabolites were highly correlated with the difference. Finally, pathway enrichment analysis indicated that disorders of metabolic pathways, such as tryptophan metabolism, steroid hormone biosynthesis, and ferroptosis(linoleic acid metabolism and arachidonic acid metabolism), may be the potential mechanism of the difference. Liver injury induced by dictamnine is significantly different between males and females, which may be caused by the disorders of tryptophan metabolism, steroid hormone biosynthesis, and ferroptosis pathways.

8-Methoxyflindersine-Induced Apoptosis and Cell Cycle Disorder Involving MAPK Signaling Activation in Human Colorectal Cancer Cells.

Colorectal cancer (CRC) is one of the most common malignant tumors with a high lethal rate globally, and novel strategies for its prevention and therapy are urgently needed. In our previous work, 8-methoxyflindersine (8-MF), a quinoline alkaloid, was isolated from the Dictamni cortex, and its bioactivities were largely unknown. In this study, we found that 8-MF significantly inhibited cell viability in the CRC cell lines LoVo and RKO. The 8-MF-induced CRC cell apoptosis, as well as cell cycle disorder, were further verified by cyclins dysregulation in mRNA and protein levels. Further, the activation of MAPK family members p38 and ERK1/2 was observed after 8-MF treatment. Moreover, the protein-protein interaction of 8-MF with cyclins and MAPKs was demonstrated using the STRING database. The 8-MF could bind to p38 and ERK1/2 proteins in molecular docking. Taken together, we found that 8-MF induced apoptosis and cell cycle disorder involving MAPK signaling activation in CRC cells, indicating 8-MF as a novel lead compound candidate for the development of anti-tumor drugs for CRC.

Network pharmacology-based analysis to explore the therapeutic mechanism of Cortex Dictamni on atopic dermatitis

Ethnopharmacological relevanceDermatitis is a common clinical chronic inflammatory skin disease, which incidence has been on the rise in recent years. It not only seriously affects the physical and mental health of patients but also increase economic burden. Currently, commonly used drugs such as corticosteroids, anti-histamines have certain side effects or are expensive. Therefore, the search for an alternative therapy for dermatitis has important clinical significance. Cortex Dictamni is a commonly used traditional Chinese medicine for expelling wind and itching, but its mechanism for treating dermatitis is still unclear. Materials and methodsNetwork pharmacological analysis was performed to predict the potential targets and pathways of Cortex Dictamni against dermatitis. Molecular docking was used to assess the binding affinity of active compounds and core targets. By repeatedly stimulating the ears with 1-fluoro-2,4-dinitrobenzene (DNFB), an atopic dermatitis (AD) mouse model was established in order to study the anti-dermatitis effect of Cortex Dictamni. The skin thickness and inflammatory cell infiltration in mouse ears were assessed by tissue staining and flow cytometric. The levels of inflammatory factors were detected by enzyme-linked immunosorbent assay (ELISA), and the total protein and phosphorylation levels of related pathways were analyzed by western blotting. ResultsIn this study, 11 active ingredients, 122 Cortex Dictamni and dermatitis intersection targets were identified. The results from Gene Ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that the core targets were mainly enriched in immune response and inflammatory signaling pathways. AD mice treated with ethanol extract of Cortex Dictamni (ECD) improved the symptoms of ear skin lesions, alleviated epidermis and dermis thickening of the AD mice ears, decreased pathological immune cell infiltration and attenuated the levels of inflammatory cytokines (TLR4, IL-6, IL-17), and inhibited the hyperactivation of the PI3K-AKT, JAK1-STAT3/STAT6 signal pathways. ConclusionsCortex Dictamni can improve the symptoms of skin lesions and the degree of inflammation caused by AD, and may inhibit AD through multiple pathways, such as regulating PI3K-AKT and JAK1-STAT3/STAT6 pathways. These results not only provide experimental evidence for the clinical application of Cortex Dictamni but also provide some help for the research and development of dermatitis drugs.

Dictamnine ameliorates chronic itch in DNFB-induced atopic dermatitis mice via inhibiting MrgprA3

Chronic itch is the most prominent feature of atopic dermatitis (AD), and antihistamine treatment is often less effective in reducing clinical pruritus severity in AD. Multiple studies have shown that histamine-independent itch pathway is thought to predominate in AD-induced chronic itch. Mas-related G-protein–coupled receptor (Mrgpr) A3+ sensory neurons have been identified as one of the major itch-sensing neuron populations, and transient receptor potential (TRP) channel A1 is the key downstream of MrgprA3-mediated histamine-independent itch. MrgprA3-TRPA1 signal pathway is necessary for the development of chronic itch and may be the potentially promising target of chronic itch in AD. Dictamnine is one of the main quinoline alkaloid components of Cortex Dictamni (a traditional Chinese medicine widely used in clinical treatment of skin diseases). However, the anti-inflammatory and anti-pruritic effect of dictamnine on AD have not been reported. In this study, we used the 2,4-dinitrofluorobenzene (DNFB)-induced AD mouse model to observe the scratching behavior, inflammatory manifestations, and to detect the expression of MrgprA3 and TRPA1 in skin and DRG. The data demonstrated that dictamnine effectively inhibited AD-induced chronic itch, inflammation symptoms, epidermal thickening, inflammatory cell infiltration, and downregulated the expression of MrgprA3 and TRPA1. Furthermore, dictamnine restrained the excitability of MrgprA3+ and TRPA1+ neurons. Molecular docking also indicated that dictamnine has better binding affinity with MrgprA3. These results suggest that dictamnine may inhibit chronic itch caused by AD through the MrgprA3-TRPA1 mediated histamine-independent itch pathway, and may have a potential utility in AD treatment.

Evidence for exposure biomarkers in dictamnine-induced liver injury resulting from metabolic activation in vitro and in mice.

Dictamnine (DTN), a furoquinoline alkaloid isolated from Dictamni Cortex, is responsible for the liver injury caused by Dictamni Cortex and the preparations. Discovering new biomarkers with high specificity and sensitivity for diagnosis and tracing the source of DTN-induced liver injury is urgently needed. Considering that metabolic activation of DTN has been suggested as a primary trigger initiating hepatotoxicity, the present study aimed to investigate the bio-activation process of DTN in vitro and in mice and to explore whether the adducts could be developed as exposure biomarkers. When trapping with N-acetyl-cysteine (NAC) and glutathione (GSH) in mouse liver microsomes and CYP3A4 overexpressed L02 cells, two isomers of DTN-NAC adducts were detected in both systems and one DTN-GSH adduct was found in mouse liver microsomes. As expected, one DTN-NAC adduct was also found in plasma and bile of mice with liver injury after DTN exposure. Moreover, mouse liver microsomes were used to simulate the conjugation of serum albumin with metabolically activated DTN. The sole modified peptide 25 DAHKSEVAHR34 was found, and the oxidative metabolites of DTN might bind to the side chain amino of albumin at Arg34. The above findings not only provided confirmative evidence that DTN was metabolically activated to induce liver injury but also suggested that the adducts had the potential to be developed as exposure biomarkers of DTN-induced liver injury.

Anti-atopic dermatitis effect of a modified Huang-Lian-Jie-Du decoction and its active fraction on 2,4-dinitrobenzene and MC903-induced mouse models

BackgroundHuang-Lian-Jie-Du Decoction is a traditional Chinese medicine formula which has long been used to treat inflammatory skin disease including AD. However, Gardeniae Fructus, a component herb of HLJDD, has noticeable toxicity in liver and kidney. We therefore replaced Gardeniae Fructus with Dictamni Cortex with a hope to derive at a modified HLJDD (MHLJDD) with better safety profile. PurposeThe present study aimed to develop MHLJDD and identify its active fraction as innovative therapeutic agents for AD using 2,4-dinitrobenzene (DNCB) and calcipotriol (MC903)-sensitized mouse models of AD. MethodsMHLJDD and the combination of the 1-butanol-soluble-fraction and the water-soluble-fraction (MHLJDD-F) were given intragastrically to the DNCB-induced mice and MC903-induced mice for two weeks. The body weight, dorsal skin/ear thickness and severity of AD symptoms of the mice were measured throughout the study. Scratching behaviors were observed after drug treatment. The blood and dorsal skin/ear tissues of mice were harvested for histopathological examination and biochemical analyses. ResultsThe results revealed that DNCB- and MC903-induced AD symptoms, including skin thickening, dryness, erythema and excoriations, in the dorsal skin and ears were significantly alleviated in the MHLJDD and MHLJDD-F-treated mice. Ceramides content and protein expressions of filaggrin and loricrin were also up-regulated after treatment with MHLJDD and MHLJDD-F. In addition, skin inflammation induced by DNCB and MC903 were markedly suppressed in the MHLJDD and MHLJDD-F-treated mice, and the action mechanisms involve suppression of the release of inflammatory cytokines, as well as downregulation of the activation of NF-κB and MAPKs pathways. Besides, MHLJDD and MHLJDD-F could reverse the abundance of gut microbiota induced by DNCB in mice. ConclusionsMHLJDD and MHLJDD-F could markedly relieve AD-like symptoms induced by DNCB and MC903 in mice through, at least in part, improving the epidermal barrier function and inhibiting skin inflammation via suppressing the activation of NF-κB and MAPKs pathways and regulation of the gut microflora dysbiosis. This study reported for the first time that MHLJDD and its active fraction could be used as innovative therapeutic agents for AD.

Chemical constituents and pharmacological effects of Dictamni Cortex: a review

Dictamni Cortex, the dried root bark of Dictamnus dasycarpus, has many chemical constituents, such as alkaloids, limonoids, flavonoids, sesquiterpenoids, glycosides, and steroids.It has the effects of anti-inflammation, anti-fungi, anti-arteriosclerosis, stopping bleeding, anti-cancer, neuroprotection, and antioxidation.The chemical constituents of Dictamni Cortex are the important material basis for its medicinal effects.This paper reviewed the chemical constituents and pharmacological activities of Dictamni Cortex and analyzed the research trend and present research progress on this medicinal, with a view to its further development and utilization.

Fraxinellone Induces Hepatotoxicity in Zebrafish through Oxidative Stress and the Transporters Pathway.

Fraxinellone (FRA), a major active component from Cortex Dictamni, produces hepatotoxicity via the metabolization of furan rings by CYP450. However, the mechanism underlying the hepatotoxicity of FRA remains unclear. Therefore, zebrafish larvae at 72 h post fertilization were used to evaluate the metabolic hepatotoxicity of FRA and to explore the underlying molecular mechanisms. The results showed that FRA (10–30 μM) induced liver injury and obvious alterations in the metabolomics of zebrafish larvae. FRA induces apoptosis by increasing the level of ROS and activating the JNK/P53 pathway. In addition, FRA can induce cholestasis by down-regulating bile acid transporters P-gp, Bsep, and Ntcp. The addition of the CYP3A inhibitor ketoconazole (1 μM) significantly reduced the hepatotoxicity of FRA (30 μM), which indicated that FRA induced hepatotoxicity through CYP3A metabolism. Targeted metabolomics analysis indicates the changes in amino acid levels can be combined with molecular biology to clarify the mechanism of hepatotoxicity induced by FRA, and amino acid metabolism monitoring may provide a new method for the prevention and treatment of DILI from FRA.

The protein adduction derived from reactive metabolites of multiple furanoids in cortex Dictamni-treated mice

The association of herb medicine Cortex Dictamni (CD) with severe even fatal hepatotoxicity has been widely reported. Recently, we demonstrated that the metabolic activation of at least ten furanoids in CD was responsible for the liver injury caused by the ethanol extract of CD (ECD) in mice. Protein adduction by reactive metabolites is considered to initiate the process of liver injury. Unlike single chemicals, the mode of and the details of protein modification by multiple components in an herb is unclear. This study aimed to characterize protein adductions derived from the reactive metabolite of furanoids in ECD-treated mice and define the association of protein adduction with liver injury. The hepatic cysteine- and lysine-based protein adducts derived from epoxide or cis-enedione of at least six furanoids were identified in mice. The furanoids with an earlier serum content Tmax were mainly to bind with hepatic glutathione and no protein adducts were formed except for dictamnine. The hepatic proteins were modified by the later absorbed furanoids. The levels of hepatic protein adduct were correlated with the degree of liver injury. In addition, the reactive metabolites of different furanoids can simultaneously bind to the model peptide by the identical reactive moiety, indicating the additive effects of the individual furanoids in the modification of hepatic proteins. In conclusion, hepatic protein adduction by multiple furanoids may play a role in ECD-induced liver injury. The earlier absorbed furanoids were mainly to bind with glutathione whereas the hepatic proteins were modified by the later furanoids.

Dictamnine Inhibits the Adhesion to and Invasion of Uropathogenic Escherichia Coli (UPEC) to Urothelial Cells.

Uropathogenic Escherichia coli (UPEC) is the most common pathogenic bacteria associated with urinary tract infection (UTI). UPEC can cause UTI by adhering to and invading uroepithelial cells. Fimbriae is the most important virulence factor of UPEC, and a potentially promising target in developing novel antibacterial treatments. In this study, the antibacterial properties and effects of the compound dictamnine, extracted from the traditional Chinese medicine Cortex Dictamni, on the bacterial morphology, cell adhesion, and invasion of UPEC were studied. Dictamnine exhibited no obvious antibacterial activity against UPEC, but significantly impeded the ability of UPEC to adhere to and invade uroepithelial cells. RT-qPCR analysis showed that treatment downregulated the expression of type 1 fimbriae, P fimbriae, and curli fimbriae adhesion genes, and also downregulated adhesion-related receptor genes of uroepithelial cells. Transmission electron microscopy showed that dictamnine destroyed the structure of the fimbriae and the surface of the bacteria became smooth. These results suggest that dictamnine may help to prevent UTI by simultaneously targeting UPEC fimbriae and urothelial adhesin receptors, and may have a potential use as a new anti-UPEC drug.

Qualitative and quantitative analysis of Arnebiae Radix and Dictamni Cortex and efficacy study of herbal extracts on allergic contact dermatitis using 3D human reconstructed epidermis

ObjectiveTo evaluate the quality of Arnebiae Radix (AR) and Dictamni Cortex (DC) and study the efficacy of herbal extracts of these two herbs on the treatment of allergic contact dermatitis (ACD). MethodsQualitative and quantitative analysis of effective components was performed using High Performance Thin Layer Chromatography (HPTLC), High Performance Liquid Chromatography (HPLC), and HPLC-Quadrupole Time of Flight-Mass Spectrometry (HPLC-QTOF-MS). In vitro allergic ACD 3D model was established by incubating 3D reconstructed human epidermis (RHE) with skin sensitizer, potassium dichromate. A total of 65 gene expression that were associated with ACD, which included 24 antioxidant responsive element (ARE) and 41 SENS-IS genes were quantified by qRT-PCR. More than or equal to 10 ARE genes and 18 SENN-IS genes were induced by 1.3-fold, demonstrating the successful establishment of in vitro ACD model. Oil extracts of AR and DC were applied on the in vitro ACD model to study the efficacy. ResultsBatch 3 of AR and batch 2 of DC showed presence of all active ingredients with the highest concentrations. Active ingredients of the herbs were extracted using a special oil and formulated into herbal oil extracts. The herbal oil extracts were able to down regulate the induced genes in the in-vitro ACD skin model, bringing the tissue back to homeostatic status. ConclusionThe oil extracts showed the potent efficacy of using AR and DC in ACD treatment. The combination study will be done to optimize the formulation ratio which will be developed into a topical cream.

Multi-Omics Integration to Reveal the Mechanism of Hepatotoxicity Induced by Dictamnine.

Herb-induced liver injury (HILI) has become a great concern worldwide due to the widespread usage of herbal products. Among these products is Dictamni Cortex (DC), a well-known Traditional Chinese Medicine (TCM), widely used to treat chronic dermatosis. Dictamni Cortex has drawn increasing attention because of its hepatotoxicity caused by the hepatotoxic component, dictamnine. However, the potential hepatotoxicity mechanism of dictamnine remains unclear. Therefore, this study aimed to use the multi-omics approach (transcriptomic, metabolomic, and proteomic analyses) to identify genes, metabolites, and proteins expressions associated with dictamnine-induced hepatotoxicity. A study on mice revealed that a high dose of dictamnine significantly increases serum aspartate aminotransferase (AST) activity, total bilirubin (TBIL), and direct bilirubin (DBIL) levels, the relative liver weight and liver/brain weight ratio in female mice (P < 0.05 and P < 0.01), compared to the normal control group. Liver histologic analysis further revealed a high dose of dictamnine on female mice caused hepatocyte vesicular steatosis characterized by hepatocyte microvesicles around the liver lobules. The expressed genes, proteins, and metabolites exhibited strong associations with lipid metabolism disorder and oxidative stress. Dictamnine caused increased oxidative stress and early hepatic apoptosis via up-regulation of glutathione S transferase a1 (GSTA1) and Bax/Bcl-2 ratio and down-regulation of the antioxidative enzymes superoxide dismutase (SOD), catalase, and glutathione peroxidase 1 (GPx-1). Besides, the up-regulation of Acyl-CoA synthetase long-chain family member 4 (ACSL4) and down-regulation of acetyl-coa acetyltransferase 1 (ACAT1) and fatty acid binding protein 1 (FABP-1) proteins were linked to lipid metabolism disorder. In summary, dictamnine induces dose-dependent hepatotoxicity in mice, which impairs lipid metabolism and aggravates oxidative stress.

Dictamnine is an effective anti‐anaphylactoid compound acting via the MrgX2 receptor located on mast cells

Anaphylactoid reactions are potentially fatal allergic diseases caused by mast cells (MCs), which release histamine and lipid mediators under certain stimuli. Therefore, there is an urgent need to develop new drug candidates to treat anaphylactoid reactions. The MrgX2 receptor mediates anaphylactoid reactions that cause inflammatory diseases. Cortex dictamni is a Chinese herb used for treating allergy-related diseases; however, its active compound is still unknown and its mechanism of action has not yet been reported. The aim of this study was to screen the anti-anaphylactoid compound from C. dictamni extracts. An MrgX2/CMC-HPLC method was established for screening MrgX2-specific compounds retained from the alcohol extract of C. dictamni. A mouse model of hindpaw extravasation was used to evaluate the anti-anaphylactoid effect of this ingredient. Intracellular Ca2+ mobilization was assessed using a calcium imaging assay. Enzyme immunoassays were performed to measure cytokine and chemokine release levels. The molecular signaling pathways were explored by western blotting. As a result, dictamnine was identified as an effective compound using the MrgX2/CMC method, which remarkably suppressed MC intracellular Ca2+ mobilization and the release of de novo degranulated substances, and inhibited PKC-PLCγ-IP3R-associated protein signaling molecules. Hence, dictamnine is a novel therapeutic candidate for anaphylactoid reactions via MrgX2.