Anti-inflammatory mechanism and active ingredients of the Chinese tallow tree

New cembranoid with potent anti-inflammatory effect isolated from Boswellia sacra by inactivating the NF-κB signaling pathway

Boswellia sacra has the properties of activating blood circulation, fixing pain, subduing swelling and promoting muscle growth. However, the anti-inflammatory active ingredients and molecular mechanisms of Boswellia sacra are still not clearly explored. Boswellia sacra was grounded and extracted using 95% ethanol, the extracts were separated by column chromatography preparation to give compounds. Spectral analysis and quantum calculations confirmed the structures of compounds and identified compound 1 as a new compound. Compounds 1-3 showed potent inhibitory activities and their effects on inflammatory mediator NO and inflammatory cytokines were examined by ELISA assay. Furthermore, their modulatory mechanism on inflammatory signal pathways was explored.

Promising remedies for cardiovascular disease: Natural polyphenol ellagic acid and its metabolite urolithins

BACKGROUND

Cardiovascular disease (CVD) is a significant worldwide factor contributing to human fatality and morbidity. With the increase of incidence rates, it is of concern that there is a lack of current therapeutic alternatives because of multiple side effects. Ellagic acid (EA), the natural polyphenol (C₁₄H₆O₈), is abundant in pomegranates, berries, and nuts. EA and its intestinal microflora metabolite, urolithins, have recently attracted much attention as a potential novel "medicine" because of their wide pharmacological properties.

PURPOSE

This study aimed to critically analyze available literature to summarize the beneficial effects of EA and urolithins, and highlights their druggability and therapeutic potential in various CVDs.

METHODS

We systematically studied research and review articles between 1984 and 2022 available on various databases to obtain the data on EA and urolithins with no language restriction. Their cardiovascular protective activities, underlying mechanism, and druggability were highlighted and discussed comprehensively.

RESULTS

We found that EA and urolithins may exert preventive and curative effects on CVD with negligible side effects and possibly regulate lipid metabolism imbalance, pro-inflammatory factor production, vascular smooth muscle cell proliferation, cardiomyocyte apoptosis, endothelial cell dysfunction, and Ca²⁺ intake and release. Potentially, this may lead to the prevention and amelioration of atherosclerosis, hypertension, myocardial infarction, cardiac fibrosis, cardiomyopathy, cardiac arrhythmias, and cardiotoxicities in vivo. Several molecules and signaling pathways are associated with their therapeutic actions, including phosphatidylinositol 3-kinase/protein kinase B, mitogen-activated protein kinase, NF-κB, nuclear factor erythroid-2 related factor 2, sirtuin1, miRNA, and extracellular signal-regulated kinase 1/2.

CONCLUSION

In vitro and in vivo studies shows that EA and urolithins could be used as valid candidates for early prevention and effective therapeutic strategies for various CVDs.

Cytotoxicity and Biomineralization Potential of Flavonoids Incorporated into PNVCL Hydrogels

This study aimed to evaluate the effects of flavonoids incorporated into poly(N-vinylcaprolactam) (PNVCL) hydrogel on cell viability and mineralization markers of odontoblast-like cells. MDPC-23 cells were exposed to ampelopsin (AMP), isoquercitrin (ISO), rutin (RUT) and control calcium hydroxide (CH) for evaluation of cell viability, total protein (TP) production, alkaline phosphatase (ALP) activity and mineralized nodule deposition by colorimetric assays. Based on an initial screening, AMP and CH were loaded into PNVCL hydrogels and had their cytotoxicity and effect on mineralization markers determined. Cell viability was above 70% when MDPC-23 cells were treated with AMP, ISO and RUT. AMP showed the highest ALP activity and mineralized nodule deposition. Extracts of PNVCL+AMP and PNVCL+CH in culture medium (at the dilutions of 1/16 and 1/32) did not affect cell viability and stimulated ALP activity and mineralized nodules’ deposition, which were statistically higher than the control in osteogenic medium. In conclusion, AMP and AMP-loaded PNVCL hydrogels were cytocompatible and able to induce bio-mineralization markers in odontoblast-cells.

Synthesis and Biological Evaluation of Gentiopicroside Derivatives as Novel Cyclooxygenase-2 Inhibitors with Anti-Inflammatory Activity

Purpose

Nonsteroidal anti-inflammatory drugs cause a series of adverse reactions. Thus, the search for new cyclooxygenase-2 selective inhibitors have become the main direction of research on anti-inflammatory drugs. Gentiopicroside is a novel selective inhibitor of cyclooxygenase-2 from Chinese herbal medicine. However, it is highly hydrophilic owing to the presence of the sugar fragment in its structure that reduces its oral bioavailability and limits efficacy. This study aimed to design and synthesize novel cyclooxygenase-2 inhibitors by modifying gentiopicroside structure and reducing its polarity.

Materials and Methods

We introduced hydrophobic acyl chloride into the gentiopicroside structure to reduce its hydrophilicity and obtained some new derivatives. Their in vitro anti-inflammatory activities were evaluated against NO, TNF-α, PGE₂, and IL-6 production in the mouse macrophage cell line RAW264.7 stimulated by lipopolysaccharide. The in vivo inhibitory activities were further tested against xylene-induced mouse ear swelling. Molecular docking predicted that whether new compounds could effectively bind to target protein cyclooxygenase-2. The inhibitory activity of new compounds to cyclooxygenase-2 enzyme were verified by the in vitro experiment.

Results

A total of 21 novel derivatives were synthesized, and exhibit lower polarities than the gentiopicroside. Most compounds have good in vitro anti-inflammatory activity. The in vivo activity results demonstrated that 8 compounds were more active than gentiopicroside. The inhibition rate of some compounds was higher than celecoxib. Molecular docking predicted that 6 compounds could bind to cyclooxygenase-2 and had high docking scores in accordance with their potency of the anti-inflammatory activity. The confirmatory experiment proved that these 6 compounds had significant inhibitory effect against cyclooxygenase-2 enzyme. Structure-activity relationship analysis presumed that the para-substitution with the electron-withdrawing groups may benefit the anti-inflammatory activity.

Conclusion

These gentiopicroside derivatives especially PL-2, PL-7 and PL-8 may represent a novel class of cyclooxygenase-2 inhibitors and could thus be developed as new anti-inflammatory agents.

Classic mechanisms and experimental models for the anti‐inflammatory effect of traditional Chinese medicine

Inflammation is a common disease involved in the pathogenesis, complications, and sequelae of a large number of related diseases, and therefore considerable research has been directed toward developing anti‐inflammatory drugs for the prevention and treatment of these diseases. Traditional Chinese medicine (TCM) has been used to treat inflammatory and related diseases since ancient times. According to the review of abundant modern scientific researches, it is suggested that TCM exhibit anti‐inflammatory effects at different levels, and via multiple pathways with various targets, and recently a series of in vitro and in vivo anti‐inflammatory models have been developed for anti‐inflammation research in TCM. Currently, the reported classic mechanisms of TCM and experimental models of its anti‐inflammatory effects provide reference points and guidance for further research and development of TCM. Importantly, the research clearly confirms that TCM is now and will continue to be an effective form of treatment for many types of inflammation and inflammation‐related diseases.

Genus Sapium (Euphorbiaceae): A review on traditional uses, phytochemistry, and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Genus Sapium, belonging to Euphorbiaceae family, has a wide distribution in Asia and in temperate and tropical regions of Africa and America. The various parts of Sapium species have been used in traditional Chinese herbal medicine for the treatment of edema, skin-related diseases, bacterial infections, cancers, diabetes, and other ailments.

AIM OF THE STUDY

A comprehensive and updated review on the phytochemistry, pharmacology, and traditional medicinal uses of Sapium has been summarized and discussed to facilitate further exploitation of the therapeutic values of Sapium species.

MATERIALS AND METHODS

The relevant information of Sapium species was collected by scientific search engines including Elsevier, Google Scholar, Scifinder, and CNKI (China national knowledge infrastructure), and Master's dissertations and Summon from Shandong University Library.

RESULTS

Phytochemical studies revealed that approximately 259 compounds including terpenoids, phenylpropanoids, flavonoids, tannins, steroids, alkaloids, etc. have been isolated and identified from Sapium species, among which terpenoids, phenylpropanoids and tannins are the main constituents. Pharmacological in vitro and in vivo studies revealed that the extracts and pure compounds possessed significant antibacterial, antiinflammatory, antioxidant, antihypertensive effects, cytotoxicity, antidiabetic, molluscicidal effects. Terpenoids, phenylpropanoids, tannins, flavonoids, and alkaloids may be responsible for these activities.

CONCLUSIONS

The traditional uses, phytochemistry, and pharmacology described in this article demonstrated that the plants of Sapium genus possess many different types of compounds exhibiting wide range of biological activities, and they have high medicinal value and potential in the treatment of a variety of diseases. Detailed phytochemical studies have been conducted on only twelve species in the literature. More wide-ranging studies are still needed to explore this genus. Most of the existing bioactivity-related studies were implemented on crude extracts. More in-depth studies are necessary to reveal the links between the traditional uses and bioactivity in the future.

Astragalin Alleviates Neuropathic Pain by Suppressing P2X4-Mediated Signaling in the Dorsal Root Ganglia of Rats

Neurologic damage often leads to neuropathic pain, for which there are no effective treatments owing to its complex pathogenesis. The purinergic receptor P2X4 is closely associated with neuropathic pain. Astragalin (AST), a compound that is used in traditional Chinese medicine, has protective effects against allergic dermatitis and neuronal injury, but its mechanism of action is not well understood. The present study investigated whether AST can alleviate neuropathic pain in a rat model established by chronic constriction injury (CCI) to the sciatic nerve. The model rats exhibited pain behavior and showed increased expression of P2X4 and the activated satellite glial cell (SGC) marker glial fibrillary acidic protein in dorsal root ganglia (DRG). AST treatment partly abrogated the upregulation of P2X4, inhibited SGC activation, and alleviated pain behavior in CCI rats; it also suppressed ATP-activated currents in HEK293 cells overexpressing P2X4. These data demonstrate that AST relieves neuropathic pain by inhibiting P2X4 and SGC activation in DRG, highlighting its therapeutic potential for clinical pain management.

Reduced cutaneous inflammation associated with antioxidant action after topical application of the aqueous extract of Annona muricata leaves

Annona muricata L. is used in folk medicine for treatment of diseases related to inflammatory and oxidative processes. This study investigated the effect of the aqueous extract of A. muricata leaves (AEAM) on TPA-induced ear inflammation and antioxidant capacity, both in vitro and in vivo. The in vitro antioxidant capacity of AEAM was measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing/antioxidant power (FRAP) and lipoperoxidation assays. Cytotoxicity and reactive oxygen species (ROS) release were evaluated in the L929 fibroblasts. Swiss mice were submitted to TPA application and were topically treated with AEAM (0.3, 1 or 3 mg/ear). After 6 h, inflammatory and oxidative parameters were evaluated. Quercetin 3-glucoside, rutin, chlorogenic acid, catechin and gallic acid were identified in AEAM. It also presented antioxidant activity in all in vitro assays used. Incubation with AEAM did not cause cell cytotoxicity but reduced ROS release from fibroblasts. Compared with the control group, treatment with AEAM significantly reduced ear oedema and mieloperoxidase activity in inflamed ears, as well as histological parameters of inflammation. These results were associated with the reduction of total hydroperoxides and modulation of catalase, but not superoxide dismutase activity. These findings show the anti-inflammatory effect of AEAM is associated with antioxidant capacity.