Sesquiterpene lactones from Ambrosia arborescens Mill. inhibit pro-inflammatory cytokine expression and modulate NF-κB signaling in human skin cells

Deubiquitinase OTUD7B Regulates Cell Proliferation in Breast Cancer

PURPOSE

The deubiquitylase OTUD7B plays a facilitates role in lung tumorigenesis through VEGF protein, but its role in breast cancer remains unclear. In the present study, we proposed to explore the role of deubiquitylase OTUD7B in breast cancer.

METHODS

The expression of OTUD7B in breast cancer and adjacent tissues was detected. The role of OTUD7B in cell proliferation and invasion of breast cancer cell lines such as MCF-7 and MDA-MB-453 was explored.

RESULTS

OTUD7B is highly expressed in human breast cancer tissues and its higher expression correlates with better survival of patients. Further mechanistic studies reveal that OTUD7B associates with RASGRF1 and PLCE1 to disrupt RAS signaling pathway. Knockdown of OTUD7B results in decreasing levels of RASGRF1 protein, suppression cell growth and invasion in breast cancer. Collectively, our results reveal a previously unappreciated anti-oncogentic role OTUD7B involved in RAS signaling pathway in breast cancer and indicate that deubiquitylases could induce tumor-suppressing or tumor-promoting activities in a cell- and tissue-dependent context.

Microwave-Assisted Extraction of Secondary Metabolites Using Ethyl Lactate Green Solvent from Ambrosia arborescens: LC/ESI-MS/MS and Antioxidant Activity

Alternative solvents are being tested as green solvents to replace the traditional organic solvents used in both academy and industry. Some of these are already available, such as ethyl lactate, cyrene, limonene, glycerol, and others. This alternative explores eco-friendly processes for extracting secondary metabolites from nature, thus increasing the number of unconventional extraction methods with lower environmental impact over conventional methods. In this context, the Peruvian Ambrosia arborescens was our model while exploring a microwave-assisted extraction (MAE) approach over maceration. The objective of this study was to perform a phytochemical study including UHPLC-ESI-MS/MS and the antioxidant activity of Ambrosia arborescens, using sustainable strategies by mixing both microwaves and ethyl lactate as a green solvent. The results showed that ethyl lactate/MAE (15.07%) achieved a higher extraction yield than methanol/maceration (12.6%). In the case of the isolation of psilostachyin, it was similar to ethyl lactate (0.44%) when compared to methanol (0.40%). Regarding UHPLC-ESI-MS/MS studies, the results were similar. Twenty-eight compounds were identified in the ethyl lactate/MAE and methanol/maceration extracts, except for the tentative identification of two additional amino acids (peaks 4 and 6) in the MeOH extract. In relation to the antioxidant assay, the activity of the ethyl lactate extract was a little higher than the methanol extract in terms of ORAC (715.38 ± 3.2) and DPPH (263.04 ± 2.8). This study on A. arborescens demonstrated that the unconventional techniques, such as MAE related to ethyl lactate, could replace maceration/MeOH for the extraction and isolation of metabolites from diverse sources. This finding showed the potential of unconventional methods with green solvents to provide eco-friendly methods based on green chemistry.

Skin irritation assessment and potential mechanism of Capparis spinosa L. fruits

ETHNOPHARMACOLOGICAL RELEVANCE

In China, Capparis spinosa L. fruits (CSF) are often used topically in Uyghur folk medicine in treating rheumatic diseases with remarkable efficacy. However, it has noticed severe skin irritation after a short time application with high dose of CSF, which limited long-term clinical use. To date, there is almost no research related to skin irritation of CSF.

AIM OF THE STUDY

This study was intended to perform the first systematic assessment of morphological and histological changes in skin after stimulation with CSF. Furthermore, potential irritant components in CSF and related mechanisms were explored by in vitro transdermal techniques, network pharmacology, molecular docking, and experimental validation.

MATERIALS AND METHODS

Skin changes after single and multiple stimulations with CSF were observed and subjected to skin irritation response scoring, irritation strength assessment, and histopathological analysis. In addition, in vitro transdermal technology, liquid chromatography-mass spectrometry (LC-MS) method, network pharmacology, molecular docking, and experimental validation were used to further exploit underlying skin irritant components and possible mechanisms of action.

RESULTS

CSF induced significant morphological (erythema and edema) and histological (epidermal thickening and inflammatory infiltration) changes in skin of mice, which were similar to the clinical presentation of irritation contact dermatitis (ICD). The ethyl acetate fraction of CSF (CFEAF) was the main source of CSF-induced skin irritation. Kaempferol, flazin, and gallic acid were potential major irritant compounds. Moreover, CFEAF, kaempferol, flazin, and gallic acid could increase the levels of pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and interleukin-17A (IL-17A) to promote skin inflammation. The potential mechanism of CSF-induced skin irritation may be activation of the nuclear factor kappa-B (NF-κB) signaling pathway, including phosphorylation of NF-κB p65 (p65) and nuclear factor-kappa B inhibitor alpha (IκBα).

CONCLUSION

Kaempferol, flazin, and gallic acid are potential skin irritant components from CSF. Altogether, they induce skin irritation responses through promoting the release of the inflammatory factors TNF-α and ICAM-1, as well as activating the NF-κB signaling pathway. In addition, IL-17A may be an important pro-inflammatory factor in skin irritation.

Hysterolides A-I, dimeric or monomeric sesquiterpene lactones from Parthenium hysterophorus L

Nine undescribed sesquiterpene lactones, including two pseudoguaianolide dimers (1 and 2), a pseudoguaiac dilactone (3), and six pseudoguaianolides (4-9), along with 13 known analogues (10-22) were isolated from Parthenium hysterophorus. Among them, hysterolide A (1) possesses an unusual carbon skeleton with a unique cyclobutane ring connecting two pseudoguaianolides. Hysterolide C (3) is a sesquiterpene dilactone incorporating a bicyclo[5.1.0]octane core. Spectroscopic analyses, 13C NMR and ECD calculations, and X-ray diffraction elucidated their structures and absolute configurations. Moreover, all the isolates were assayed for their anti-inflammatory activities by inhibiting LPS-induced nitric oxide production in BV-2 microglia cells, wherein, nine compounds displayed significant inhibitory activities with IC50 of 0.52-6.32 μM. Furthermore, the preliminary structure-activity relationship was also established.

Anticancer plant-derivatives: deciphering their oncopreventive and therapeutic potential in molecular terms

Background

Over the years, phytomedicines have been widely used as natural modalities for the treatment and prevention of various diseases by different ethnic groups across the globe. Although, 25% of drugs in the USA contain at least one plant-derived therapeutic compound, currently there is a paucity of plant-derived active medicinal ingredients in the pharmaceutical industry. Scientific evidence-based translation of plant-derived ethnomedicines for their clinical application is an urgent need. The anticancer and associated properties (antioxidative, anti-inflammatory, pro-apoptotic and epithelial-mesenchymal transition (EMT) inhibition) of various plant extracts and phytochemicals have been elucidated earlier. Several of the plant derivatives are already in use under prophylactic/therapeutic settings against cancer and many are being investigated under different phases of clinical trials.

Main body

The purpose of this study is to systematically comprehend the progress made in the area of prophylactic and therapeutic potential of the anticancerous plant derivatives. Besides, we aim to understand their anticancer potential in terms of specific sub-phenomena, such as anti-oxidative, anti-inflammatory, pro-apoptotic and inhibition of EMT, with an insight of the molecules/pathways associated with them. The study also provides details of classes of anticancer compounds, their plant source(s) and the molecular pathway(s) targeted by them. In addition to the antioxidative and antiproliferative potentials of anticancer plant derivatives, this study emphasizes on their EMT-inhibition potential and other ‘anticancer related’ properties. The EMT is highlighted as a phenomenon of choice for targeting cancer due to its role in the induction of metastasis and drug resistance. Different phytochemicals in pre-clinical or clinical trials, with promising chemopreventive/anticancer activities have been enlisted and the plant compounds showing synergistic anticancer activity in combination with the existing drugs have been discussed. The review also unravels the need of carrying out pan-signalome studies for identifying the cardinal pathways modulated by phytomedicine(s), as in many cases, the molecular pathway(s) has/have been randomly studied.

Conclusion

This review systematically compiles the studies regarding the impact of various plant derivatives in different cancers and oncogenic processes, as tested in diverse experimental model systems. Availability of more comprehensive information on anticancer phyto-constituents, their relative abundance in crude drugs, pathways/molecules targeted by phytomedicines, their long-term toxicity data and information regarding their safe use under the combinatorial settings, would open greater avenues of their utilization in future against this dreaded disease.

Graphical Abstract

A comprehensive phytochemical and pharmacological review on sesquiterpenes from the genus Ambrosia

Sesquiterpenes are bitter secondary metabolites characteristic to the genus Ambrosia (Asteraceae) and constitute one of the most diverse classes of terpenoids. These compounds exhibit broad-spectrum bioactivities, such as antiproliferative, cytotoxic, antimicrobial, anti-inflammatory, molluscicidal, schistomicidal, larvicidal, and antiprotozoal activities. This review compiles and discusses the chemistry and pharmacology of sesquiterpenes of the Ambrosia species covering the period between 1950 and 2021. The review identified 158 sesquiterpenes previously isolated from 23 different Ambrosia species collected from across the American, African, and Asian continents. These compounds have guaiane, pseudoguaiane, seco-pseudoguaiane, daucane, germacrane, eudesmane, oplopane, clavane, and aromadendrane carbon skeletons. Most sesquiterpene compounds predominantly harbor the pseudoguaiane skeleton, whereas the eudesmanes have the most varied substituents. Antiproliferative and antiprotozoal activities are the most promising bioactivities of sesquiterpenes in Ambrosia and could lead to new pathways toward drug discovery.

Perindopril/Ambrosin Combination Mitigates Dextran Sulfate Sodium-Induced Colitis in Mice: Crosstalk between Toll-like Receptor 4, the Pro-Inflammatory Pathways, and SIRT1/PPAR-γ Signaling

Colitis is one of the inflammatory states that affect the intestinal wall and may even predispose to malignancy due to chronic irritation. Although the etiology of colitis is not yet fully explored, a combination of genetic and environmental factors is strongly incriminated. Perindopril is an angiotensin-converting enzyme inhibitor that is used for the management of a wide range of cardiovascular diseases. Ambrosin is a sesquiterpene lactone that was proven to have beneficial effects in disorders characterized by inflammatory nature. The objective of this study is to make a comparison between the effects of perindopril or ambrosin on dextran sulfate sodium (DSS)-induced colitis in mice and to explore the effect of their combination. The present findings indicate that each ambrosin or perindopril alone or in combination is able to ameliorate oxidative stress and suppress the proinflammatory pathways in the colonic tissues of DSS-treated mice via mechanisms related to toll-like receptor 4/nuclear factor kappa B signaling and modulation of peroxisome proliferator-activated receptor gamma/sirtuin-1 levels. In addition, each ambrosin or perindopril alone or in combination inhibits apoptosis and augments the mediators of autophagy in DSS-treated mice. These effects are reflected in the amelioration of the histopathological and electron microscopic changes in the colonic tissues. Interestingly, the most remarkable effects are those encountered with the perindopril/ambrosin combination compared to the groups treated with each of these agents alone. In conclusion, the perindopril/ambrosin combination might represent an effective modality for mitigation of the pathogenic events and the clinical sequelae of colitis.

The Modulatory Influence of Plant-Derived Compounds on Human Keratinocyte Function

The plant kingdom is a rich source of secondary metabolites with numerous properties, including the potential to modify keratinocyte biology. Keratinocytes are important epithelial cells that play a protective role against various chemical, physical and biological stimuli, and participate in reactive oxygen scavenging and inflammation and wound healing processes. The epidermal cell response may be modulated by phytochemicals via changes in signal transduction pathways. Plant extracts and single secondary compounds can possess a high antioxidant capacity and may suppress reactive oxygen species release, inhibit pro-apoptotic proteins and apoptosis and activate antioxidant enzymes in keratinocytes. Moreover, selected plant extracts and single compounds also exhibit anti-inflammatory properties and exposure may result in limited production of adhesion molecules, pro-inflammatory cytokines and chemokines in keratinocytes. In addition, plant extracts and single compounds may promote keratinocyte motility and proliferation via the regulation of growth factor production and enhance wound healing. While such plant compounds may modulate keratinocyte functions, further in vitro and in vivo studies are needed on their mechanisms of action, and more specific toxicity and clinical studies are needed to ensure their effectiveness and safety for use on human skin.

Sesquiterpene lactones; Damsin and neoambrosin suppress cytokine-mediated inflammation in complete Freund's adjuvant rat model via shutting Akt/ERK1/2/STAT3 signaling

ETHNOPHARMACOLOGIAL RELEVANCE

Although Damsissa (Ambrosia maritima) is traditionally used as anti-inflammatory and diuretic, the biological activity and mechanism of action of its major constituents are to be elucidated.

AIM

to decipher the anti-arthritic potential of damsin (DMS) and neoambrosin (NMS) and to unfold their molecular signaling in complete Freund's adjuvant (CFA)-induced arthritis model.

MATERIALS AND METHODS

the right hind paw was inoculated with CFA (0.1 ml) at day 0 and 7 while treatments were started from the 14^th day and continued for 2 weeks. Rats were randomly assigned into 4 groups; normal group (NRML), CFA-induced arthritis group, CFA-induced arthritis treated with DMS and NMS (10 mg/kg/day) as 3^rd and 4^th group; respectively.

RESULTS

Throughout experimental period, treatments ameliorated the increase of paw volume, knee joint diameter and nociception tests as reflected in open field arena. Also, DSM and NMS suppressed phosphorylation of Akt, STAT-3, ERK1/2 which was further mirrored by inactivation of GSK3β and downregulation of MCP-1 together with CCN1 and NF-kβ in hind paw tissue. Concomitantly, inflammation markers; TNF-α, IL-6, -12 were lowered as confirmed microscopically during examination of hind paw tissue.

CONCLUSION

DSM and NMS-induced suppression of NF-kβ subdues clinical features of RA most probably through repression of Akt/ERK1/2/STAT3 pathway. Therefore, DMS and NMS can serve as safe and effective treatment for rheumatoid arthritis, one of the most disabling chronic, inflammatory and painful autoimmune disease.

Impact of sesquiterpene lactones on the skin and skin-related cells? A systematic review of in vitro and in vivo evidence

Although anti-inflammatory properties are attributed to sesquiterpene lactones (SL), cutaneous hypersensitivity reactions are proposed as limitations for SL-based therapies. Thus, the impact of SL on the skin and skin-related cells was systematically reviewed. Studies indexed in electronic databases were screened from the PRISMA strategy. The risk of bias in all studies was verified from the SYRCLE's tool. Thirty original studies were recovered and analyzed. Mice and guinea pig, keratinocytes and fibroblasts were predominantly investigated from in vivo and in vitro studies, respectively. In vivo studies indicated that most SL induced contact dermatitis associated with edema, erythema, and inflammatory infiltrate. Conversely, in vitro evidence was consistent with a dose-dependent anti-inflammatory effect of SL in response to reduced cytokines, 5-LOX, and COX-2 levels or activity in keratinocytes, fibroblasts, macrophages and dendritic cells; which are events potentially triggered by downregulation of gene expression and/or inhibition of the NF-κB signaling pathway. In vivo studies presented uncertain to high-risk of bias mainly associated with underreporting of randomization and experimental blinding. The current evidence supports potent cutaneous immunomodulatory properties of SL. Although in vitro and in vivo studies indicate opposite anti- or proinflammatory effects, this contradiction exhibits a dose-dependent component. In addition, the anti-inflammatory pathways activated by SL are better understood from in vitro evidence. However, additional studies are required to elucidating specific anti-inflammatory and proinflammatory mechanisms triggered by SL in vivo. Thus, controlling the sources of bias described in this review can contribute to improving the quality of the evidence in further investigations.

Pleurotus ostreatus as a Biocatalyst to Obtain Bicyclic Hydroxylactones with Three or Four Methyl Groups

The purpose of the study was to explore microbial transformations in cultures of basidiomycetes Pleurotus ostreatus, two bicyclic unsaturated lactones occurring in the form of two diastereoisomers. Some of these strains were able to transform unsaturated lactones into four known and three new derivatives. The structures of all lactones were established on the basis of spectroscopic data. Both substrates and products caused a complete inhibition of growth of A. alternata and F. linii strains.

Ambrosin, a potent NF-κβ inhibitor, ameliorates lipopolysaccharide induced memory impairment, comparison to curcumin

Despite its poor bioavailability, curcumin is a promising natural polyphenol targeting NF-κβ. NF-κβ is a target for new therapeutics because it plays a pivotal role in the pathophysiology of Alzheimer disease (AD). In contrast, ambrsoin, a sesquiterpene lactone which is a potent NF-κβ inhibitor, is scarcely studied in AD models. The current work aims to assess the efficacy of ambrosin as a possible remedy for AD. In silico studies showed that bioavailability and BBB permeability could be favorable for ambrosin over curcumin. Memory impairment was induced in mice by single intraperitoneal injection of LPS (0.4 mg/kg). Treated groups received curcumin (100 mg/kg) or ambrosin at doses (5 or 10 mg/kg) for 7 days. Mice in treated groups showed a significant improvement in memory functions during Morris water maze and object recognition tests. Curcumin and ambrosin (10 mg/kg) inhibited the upsurge of NF-κβp65 transcript and protein levels. Consequently, downstream pro-inflammatory and nitrosative mediators were inhibited, namely, TNF-α, IL-1β, COX-2 and iNOS. BACE1 was inhibited, thereby reducing amyloid plaques (Aβ) deposition and eventually reducing inflammation and apoptosis of neurons as revealed by immunohistopathological examination. In conclusion, ambrosin can be repurposed as AD remedy after further pharmacokinetic/pharamacodynamic assessments. It could serve as an additional lead drug for AD therapeutics.

Bioassay-Guided Isolation and Structure Elucidation of Fungicidal and Herbicidal Compounds from Ambrosia salsola (Asteraceae)

The discovery of potent natural and ecofriendly pesticides is one of the focuses of the agrochemical industry, and plant species are a source of many potentially active compounds. We describe the bioassay-guided isolation of antifungal and phytotoxic compounds from the ethyl acetate extract of Ambrosia salsola twigs and leaves. With this methodology, we isolated and identified twelve compounds (four chalcones, six flavonols and two pseudoguaianolide sesquiterpene lactones). Three new chalcones were elucidated as (S)-β-Hydroxy-2',3,4,6'-tetrahydroxy-5-methoxydihydrochalcone (salsolol A), (S)-β-Hydroxy-2',4,4',6'-tetrahydroxy-3-methoxydihydrochalcone (salsolol B), and (R)-α, (R)-β-Dihydroxy-2',3,4,4',6'- pentahydroxydihydrochalcone (salsolol C) together with nine known compounds: balanochalcone, six quercetin derivatives, confertin, and neoambrosin. Chemical structures were determined based on comprehensive direct analysis in real time-high resolution mass spectrometry (HR-DART-MS), as well as 1D and 2D NMR experiments: Cosy Double Quantum Filter (DQFCOSY), Heteronuclear Multiple Quantum Coherence (HMQC) and Heteronuclear Multiple Bond Coherence (HMBC), and the absolute configurations of the chalcones were confirmed by CD spectra analysis. Crystal structure of confertin was determined by X-ray diffraction. The phytotoxicity of purified compounds was evaluated, and neoambrosim was active against Agrostis stolonifera at 1 mM, while confertin was active against both, Lactuca sativa and A. stolonifera at 1 mM and 100 µM, respectively. Confertin and salsolol A and B had IC50 values of 261, 275, and 251 µM, respectively, against Lemna pausicotata (duckweed). The antifungal activity was also tested against Colletotrichum fragariae Brooks using a thin layer chromatography bioautography assay. Both confertin and neoambrosin were antifungal at 100 µM, with a higher confertin activity than that of neoambrosin at this concentration.