Glabretal-type triterpenoid from the root bark of Dictamnus dasycarpus ameliorates collagen-induced arthritis by inhibiting Erk-dependent lymphocyte proliferation

Anti-atopic dermatitis effect of fraxinellone via inhibiting IL-31 in vivo and in vitro

Chronic recurrent itch and skin inflammation are prominent features of atopic dermatitis (AD), which is closely related to the immune response driven by T-helper type 2 (Th2) cells. The expression of interleukin 31 (IL-31) is positively correlated with the severity of dermatitis. Anti-IL-31 receptor α (IL-31RA) targeted drugs have been used to treat AD, however, they are expensive and have side effects. Fraxinellone (FRA) is one of the main limonoid components in the dried root bark of Dictamnus dasycarpus Turcz.; however, its anti-inflammatory and antipruritic effects on atopic dermatitis (AD) have not been previously reported. In this study, we investigated the anti-dermatitis effect of FRA and its potential mechanism of action using a 2,4-dinitrofluorobenzene (DNFB)-induced AD-like mouse model and lipopolysaccharide (LPS)-stimulated HaCaT cells. FRA significantly inhibited chronic pruritus, epidermal thickening, and inflammatory infiltration in AD mice. FRA not only inhibited the levels of IL-31 in the serum and lesioned skin of AD mice but also significantly downregulated the mRNA expression and protein levels of IL-31, IL-31RA, transient receptor potential (TRP) V1, and TRPA1 in the lesioned skin and dorsal root ganglion (DRG) of AD mice. In LPS-stimulated HaCaT cells, FRA inhibited the production of iNOS and COX2, as well as the protein levels of IL-31, IL-31RA, TRPV1 and TRPA1, showing significant anti-inflammatory effects. In summary, our findings suggest that FRA exerts antipruritic and anti-inflammatory effects in AD by regulating the IL-31 pathway, and may hold promise for the clinical treatment of AD.

Mechanistic insights into anti-inflammatory and immunosuppressive effects of plant secondary metabolites and their therapeutic potential for rheumatoid arthritis

The anti-inflammatory and immunosuppressive activities of plant secondary metabolites are due to their diverse mechanisms of action against multifarious molecular targets such as modulation of the complex immune system associated with rheumatoid arthritis (RA). This review discussed and critically analyzed the potent anti-inflammatory and immunosuppressive effects of several phytochemicals and their underlying mechanisms in association with RA in experimental studies, including preliminary clinical studies of some of them. A wide range of phytochemicals including phenols, flavonoids, chalcones, xanthones, terpenoids, alkaloids, and glycosides have shown significant immunosuppressive and anti-inflammatory activities in experimental RA models and a few have undergone clinical trials for their efficacy and safety in reducing RA symptoms and improve patient outcomes. These phytochemicals have potential as safer alternatives to the existing drugs in the management of RA, which possess a wide range of serious side effects. Sufficient preclinical studies on safety and efficacy of these phytochemicals must be performed prior to proper clinical studies. Further studies are needed to address the barriers that have so far limited their human use before the therapeutic potential of these plant-based chemicals as anti-arthritic agents in the treatment of RA is fully realized.

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

ETHNOPHARMACOLOGICAL RELEVANCE

Dermatitis 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 METHODS

Network 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.

RESULTS

In 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.

CONCLUSIONS

Cortex 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.

A review on traditional usages, chemical constituents and pharmacological activities of periploca forrestii schltr

ETHNOPHARMACOLOGICAL RELEVANCE

Periploca forrestii Schltr. was listed as a classical medicinal plant in "Miao medicine", which is a branch of traditional Chinese medicine (TCM). According to the theory of TCM, P. forrestii has the efficacy of relaxing tendons and activating collaterals, and dispelling wind and eliminating dampness. Hence, it was often used for the therapy of rheumatoid arthritis and traumatic injury in clinical practice.

AIMS OF THE REVIEW

This review aims to present comprehensive information for the research progress of P. forrestii. The researches on botany, traditional uses, phytochemistry, pharmacology and toxicology of the plant are summarized. We mainly focus on the phytochemical and pharmacological investigations. As a representative class of phytochemicals in P. forrestii, more attention is paid to cardiac glycosides. The insights into potential action of mechanisms and possible future studies on P. forrestii are also discussed.

MATERIALS AND METHODS

Relevant literature was acquired from scientific databases including Google Scholar, Web of Science, Scifinder, Baidu Scholar, PubMed and Chinese national knowledge infrastructure. Monographs and Chinese pharmacopoeia were also utilized as references.

RESULTS

To date, all kinds of phytochemical constituents have been isolated and identified from this plant including cardiac glycosides, steroids, terpenoids, flavonoids, phenylpropanoids, quinones, organic phenolic acids and others. Among these, cardiac glycosides were considered as the major ingredients and bioactive materials. Modern pharmacological studies demonstrated that the plant possessed extensive bioactivity, such as anti-inflammatory and analgesic effects, immunosuppressive action, wound healing activity, antioxidant, anti-tumor and, cardiotonic properties.

CONCLUSIONS

As an important medicinal plant, lots of studies have proved that P. forrestii has significant therapeutical effects, especially on rheumatoid arthritis and traumatic injury. These results provide modern scientific evidence for traditional use and contribute to the development of novel remedies for chronic diseases. However, the exact mechanism of action remains to be elucidated. Furthermore, the long-term in vivo toxicity and clinical efficacy also require in-depth exploration in the future.

Anti-inflammatory effects of a methanol extract of Dictamnus dasycarpus Turcz. root bark on imiquimod-induced psoriasis

BACKGROUND

The root bark of Dictamnus dasycarpus Turcz. has been successfully used for the treatment of inflammatory skin conditions such as eczema and pruritus. However, the anti-psoriatic effect of this plant has not until now been investigated.

METHODS

The aim of this project was to investigate whether a methanol extract of Dictamnus dasycarpus Turcz. root bark (MEDD) can be used as a therapeutic agent for psoriasis in C57BL/6 mice model of imiquimod (IMQ)-induced psoriasis. IMQ and MEDD was applied to mouse skin continuously for 7 days. The skin phenotype and the levels of inflammatory cytokines, such as interferon (IFN)-γ and interleukin (IL)-17, were analyzed. The immune cell population was determined by flow cytometry, and STAT1 and 3 protein levels were measured.

RESULTS

An alleviation of scaly skin phenotype, immune cell infiltration in the dermis, and epidermal hyperplasia was observed after daily MEDD treatment in the lesion-affected area. It was also found that MEDD reduced IL-17 cytokine levels decreased by 44.37% (p < 0.05), the number of IL-17-producing Th17 cells and γδT cells, and the size of the Th1 population secreting IFN-γ decreased by 45.98, 62.21, and 44.42%, respectively (p < 0.05), compared with the vehicle control group. STAT3 signals, associated with IL-17 are also reduced by MEDD.

CONCLUSIONS

An anti-psoriatic effect of MEDD was observed, as determined by decreased skin inflammation, reduced number of inflammatory cytokines, and a smaller population of inflammatory cells. These results contribute to the validation of the use of MEDD in the treatment of psoriasis.

Anti-inflammatory constituents from Cortex Dictamni

Eight new compounds named as dictamalkosides A (1), B (2), C (3), dictamphenosides A (4), B (5), C (6), D (7) and E (8), as well as 23 known ones were obtained from the 70% EtOH extract of Cortex Dictamni. Their structures were ascertained based on the spectroscopic evidences. Among the known compounds, 14, 17-23, 25-28, and 31 were isolated from Dictamnus genus for the first time; 16 and 24 were firstly isolated from this plant. And the ¹³C NMR data of 14 was reported here for the first time. Moreover, compounds 1-8, 12, 18-21, 27 and 31 were found to exhibit potential inhibitory effect on LPS-induced NO production at 40 μM for RAW 264.7 macrophages, which suggested alkaloids and phenolic acids might be anti-inflammation therapeutic substance in Cortex Dictamni.

Ontology-based systematic representation and analysis of traditional Chinese drugs against rheumatism

Background

Rheumatism represents any disease condition marked with inflammation and pain in the joints, muscles, or connective tissues. Many traditional Chinese drugs have been used for a long time to treat rheumatism. However, a comprehensive information source for these drugs is still missing, and their anti-rheumatism mechanisms remain unclear. An ontology for anti-rheumatism traditional Chinese drugs would strongly support the representation, analysis, and understanding of these drugs.

Results

In this study, we first systematically collected reported information about 26 traditional Chinese decoction pieces drugs, including their chemical ingredients and adverse events (AEs). By mostly reusing terms from existing ontologies (e.g., TCMDPO for traditional Chinese medicines, NCBITaxon for taxonomy, ChEBI for chemical elements, and OAE for adverse events) and making semantic axioms linking different entities, we developed the Ontology of Chinese Medicine for Rheumatism (OCMR) that includes over 3000 class terms. Our OCMR analysis found that these 26 traditional Chinese decoction pieces are made from anatomic entities (e.g., root and stem) from 3 Bilateria animals and 23 Mesangiospermae plants. Anti-inflammatory and antineoplastic roles are important for anti-rheumatism drugs. Using the total of 555 unique ChEBI chemical entities identified from these drugs, our ChEBI-based classification analysis identified 18 anti-inflammatory, 33 antineoplastic chemicals, and 9 chemicals (including 3 diterpenoids and 3 triterpenoids) having both anti-inflammatory and antineoplastic roles. Furthermore, our study detected 22 diterpenoids and 23 triterpenoids, including 16 pentacyclic triterpenoids that are likely bioactive against rheumatism. Six drugs were found to be associated with 184 unique AEs, including three AEs (i.e., dizziness, nausea and vomiting, and anorexia) each associated with 5 drugs. Several chemical entities are classified as neurotoxins (e.g., diethyl phthalate) and allergens (e.g., eugenol), which may explain the formation of some TCD AEs. The OCMR could be efficiently queried for useful information using SPARQL scripts.

Conclusions

The OCMR ontology was developed to systematically represent 26 traditional anti-rheumatism Chinese drugs and their related information. The OCMR analysis identified possible anti-rheumatism and AE mechanisms of these drugs. Our novel ontology-based approach can also be applied to systematic representation and analysis of other traditional Chinese drugs.

Electronic supplementary material

The online version of this article (10.1186/s12918-017-0510-5) contains supplementary material, which is available to authorized users.