Antibacterial thymol derivatives isolated from Centipeda minima

Synthesis and antibacterial potential of novel thymol derivatives against methicillin-resistant Staphylococcus aureus and P. aeruginosa pathogenic bacteria

The increasing threat of antibiotic resistance has created an urgent need for new antibacterial agents, particularly plant-based natural compounds and their derivatives. Thymol, a natural monoterpenoid phenolic compound derived from Monarda citriodora, is known for its aromatic and therapeutic properties, including antibacterial activity. This study focuses on synthesizing dihydropyrimidinone and dihydropyridine derivatives of thymol and exploring their antibacterial properties. The synthesized compounds were tested for their in vitro antibacterial potential against pathogenic microorganisms, specifically Pseudomonas aeruginosa (Gram-negative) and methicillin-resistant Staphylococcus aureus (MRSA) (Gram-positive). Among the synthesized derivatives, compound 3i (ethyl 4-(4-hydroxy-5-isopropyl-2-methylphenyl)-2-imino-6-methyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate) exhibited the most promising antibacterial activity, with minimum inhibitory concentration (MIC) values of 12.5 µM against P. aeruginosa and 50.0 µM against MRSA. Additionally, compound 3i demonstrated a synergistic effect when combined with vancomycin, enhancing its antibacterial efficacy. The optimum fractional inhibitory concentration index (FICI) observed was 0.10 and 0.5 for MRSA and P. aeruginosa, respectively, in combination with vancomycin. In silico analysis of the physiochemical properties of 3i indicated compliance with all drug-likeness rules. Furthermore, molecular docking studies revealed that compound 3i has a stronger binding affinity to the target protein than thymol, providing valuable insights into its potential mechanism of action.

Nanoformulated herbal compounds: enhanced antibacterial efficacy of camphor and thymol-loaded nanogels

Herbal components are highly useful assets for the advancement of novel antibacterial drugs. Nanotechnology holds great promise as an approach to enhance the effectiveness and develop the composition of these substances. The study developed nanogels incorporating camphor, thymol, and a combination derived from the initial nanoemulsions with particle sizes of 103, 85, and 135 nm, respectively. The viscosity of nanogels and the successful loading of compounds in them were examined by viscometery and ATR-FTIR studies. The bactericidal properties of the nanogels were examined against four bacterial strains. The nanogel containing camphor and thymol at 1250 µg/mL concentration exhibited complete growth suppression against Pseudomonas aeruginosa and Staphylococcus aureus. The thymol nanogel at 1250 µg/mL and the camphor nanogel at 2500 µg/mL exhibited complete inhibition of growth on Listeria monocytogenes and Escherichia coli, respectively. Both nanogels showed favorable effectiveness as antibacterial agents and could potentially examine a wide range of pathogens and in vivo studies.

Arnicolide C Suppresses Tumor Progression by Targeting 14-3-3θ in Breast Cancer

Background: Arnicolide C, which is isolated from Centipeda minima, has excellent antitumor effects. However, the potential impacts and related mechanisms of action of arnicolide C in breast cancer remain unknown. Methods: The viability of breast cancer cells was measured using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and colony formation assays. For analysis of apoptosis and the cell cycle, flow cytometry was used. A molecular docking approach was used to explore the possible targets of arnicolide C. Western blot analysis was used to detect changes in the expression of 14-3-3θ and proteins in related pathways after arnicolide C treatment in breast cancer cells. The anti-breast cancer effect of arnicolide C in vivo was evaluated by establishing cell-derived xenograft (CDX) and patient-derived xenograft (PDX) models. Results: Arnicolide C inhibited proliferation, increased apoptosis, and induced G1 arrest. In particular, molecular docking analysis indicated that arnicolide C binds to 14-3-3θ. Arnicolide C reduced 14-3-3θ expression and inhibited its downstream signaling pathways linked to cell proliferation. Similar results were obtained in the CDX and PDX models. Conclusion: Arnicolide C can have an anti-breast cancer effect both in vitro and in vivo and can induce cell cycle arrest and increase apoptosis in vitro. The molecular mechanism may be related to the effect of arnicolide C on the expression level of 14-3-3θ. However, the specific mechanism through which arnicolide C affects 14-3-3θ protein expression still needs to be determined.

Bioactive Phenolate Salts: Thymol Salts

Phenolate salts of bioactive agents have been reported only scarcely. This is the first report on the formation and characterization of thymol phenolate salts as representatives of phenol-containing bioactive molecules. Thymol has been used in medicine and agriculture for decades owing to its excellent therapeutic properties. However, in light of its poor aqueous solubility, thermal instability, and especially its high chemical volatility, the utility of thymol is hampered. The present work focuses on tuning the physicochemical properties of thymol by modifying its chemical structure through salt formation. In this context, a series of metal (Na, K, Li, Cu, and Zn) and ammonium (tetrabutylammonium and choline) salts of thymol were synthesized and characterized using IR, NMR, CHN elemental analysis, and DSC analyses. The molecular formulae of thymol salts were determined based on CHN analysis and thymol quantification studies from UV-Vis spectrometric analysis. In most cases, the thymol phenolate was prepared as a 1 : 1 molar ratio with metal/ammonium ion. Only the Cu salt of thymol was isolated at a ratio of two phenolate units per copper ion. Most of the synthesized thymol salts were found to have increased thermal stability relative to thymol. The physicochemical properties such as solubility, thermal stability, and evaporation rate of thymol salts were thoroughly studied in comparison with thymol. The in vitro release studies of Cu from the copper salt of thymol is pH-dependent: rapid release of copper was observed in the lower pH release medium (100 % release at pH 1 for 12 days) and the rates of release were slower at higher pH values (5 % release at pH 2, and <1 % release at pH 4, 6, 8, and 10) over a period of about three weeks.

Centipeda minima active components and mechanisms in lung cancer

BACKGROUND

Traditional Chinese medicine (TCM) has been extensively used for neoplasm treatment and has provided many promising therapeutic candidates. We previously found that Centipeda minima (C. minima), a Chinese medicinal herb, showed anti-cancer effects in lung cancer. However, the active components and underlying mechanisms remain unclear. In this study, we used network pharmacology to evaluate C. minima active compounds and molecular mechanisms in lung cancer.

METHODS

We screened the TCMSP database for bioactive compounds and their corresponding potential targets. Lung cancer-associated targets were collected from Genecards, OMIM, and Drugbank databases. We then established a drug-ingredients-gene symbols-disease (D-I-G-D) network and a protein-protein interaction (PPI) network using Cytoscape software, and we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses using R software. To verify the network pharmacology results, we then performed survival analysis, molecular docking analysis, as well as in vitro and in vivo experiments.

RESULTS

We identified a total of 21 C. minima bioactive compounds and 179 corresponding targets. We screened 804 targets related to lung cancer, 60 of which overlapped with C. minima. The top three candidate ingredients identified by D-I-G-D network analysis were quercetin, nobiletin, and beta-sitosterol. PPI network and core target analyses suggested that TP53, AKT1, and MYC are potential therapeutic targets. Moreover, molecular docking analysis confirmed that quercetin, nobiletin, and beta-sitosterol, combined well with TP53, AKT1, and MYC respectively. In vitro experiments verified that quercetin induced non-small cell lung cancer (NSCLC) cell death in a dose-dependent manner. GO and KEGG analyses found 1771 enriched GO terms and 144 enriched KEGG pathways, including a variety of cancer related pathways, the IL-17 signaling pathway, the platinum drug resistance pathway, and apoptosis pathways. Our in vivo experimental results confirmed that a C. minima ethanol extract (ECM) enhanced cisplatin (CDDP) induced cell apoptosis in NSCLC xenografts.

CONCLUSIONS

This study revealed the key C. minima active ingredients and molecular mechanisms in the treatment of lung cancer, providing a molecular basis for further C. minima therapeutic investigation.

Thymus vulgaris, a natural pharmacy against COVID-19: A molecular review

Introduction

A worldwide pandemic infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a deadly disease called COVID-19. Interaction of the virus and the Angiotensin converting-enzyme 2 (ACE2) receptor leads to an inflammatory-induced tissue damage. Thymus vulgaris L. (TvL) is a plant with a long history in traditional medicine that has antimicrobial, antiseptic, and antiviral properties. Thymol and Carvacrol are two important biological components in Thyme that have anti-inflammatory, antioxidant, and immunomodulatory properties. This study is a molecular review on the potential effects of TvL and its active compounds on SARS-COV2 infection.

Method

This is a narrative review in which using PubMed, Scopus, ISI, Cochrane, ScienceDirect, Google scholar, and Arxiv preprint databases, the molecular mechanisms of therapeutic and protective effects of TvL and its active compounds have been discussed regarding the molecular pathogenesis in COVID-19.

Results

Thyme could suppress TNF-alpha, IL-6, and other inflammatory cytokines. It also enhances the anti-inflammatory cytokines like TGF-beta and IL-10. Thyme extract acts also as an inhibitor of cytokines IL-1-beta and IL-8, at both mRNA and protein levels. Thymol may also control the progression of neuro-inflammation toward neurological disease by reducing some factors. Thyme and its active ingredients, especially Thymol and Carvacrol, have also positive effects on the renin-angiotensin system (RAS) and intestinal microbiota.

Conclusions

Accordingly, TvL and its bioactive components may prevent COVID-19 complications and has a potential protective role against the deleterious consequences of the disease.

Chemical Composition, Antibacterial and Antioxidant Activities of Essential Oil from Centipeda minima

This study elucidated the chemical composition of essential oil from Centipeda minima (EOCM) and its antibacterial and antioxidant activities with two chemical monomers thymol and carvacrol. The main chemical composition of EOCM, analyzed by GC-MS, were trans-chrysanthenyl acetate, thymol, aromadendrene and β-caryophyllene. In the screening of antibacterial activity against S. aureus, two monomers with antibacterial activity were obtained: thymol and carvacrol. The MIC of EOCM, thymol and carvacrol were 0.625 mg/mL, 0.156 mg/mL and 0.156 mg/mL, respectively. The experimental results were shown that three drugs could inhibit the growth of S. aureus and inhibit the formation of biofilm by changing the permeability of cell membrane and interfering with the metabolic activities in bacteria. The scavenging effects of the three drugs on DPPH radical and hydroxyl radical showed that the antioxidant effect of the three drugs was EOCM > carvacrol > thymol.

Constituents of Pulicaria inuloides and Cytotoxic Activities of Two Methoxylated Flavonols

Plants of the genus Pulicaria are known for providing traditional medicines, spices, herbal teas, and insect deterrents. Pulicaria inuloides (Poir.). DC. is one of the less chemically studied species within the genus. Hydroalcoholic extracts from roots and aerial parts of P. inuloides were analyzed using the UHPLC-PAD-MSn technique and revealed the presence of six caffeoylquinic and eleven caffeoylhexaric conjugates together with hydroxykaempferol dimethyl ether and quercetagetin trimethyl ether. Moreover, constituents of chloroform extract from the whole P. inuloides plants were isolated and identified by spectroscopic methods. One new and four known caryophyllene derivatives, three thymol derivatives, and four polymethoxylated flavonols were found in the analyzed extract. The structure of the new compound was established by spectroscopic methods (HRESIMS, 1H NMR, 13C NMR, COSY, HSQC, HMBC, NOESY). The cytotoxicity of 6-Hydroxykaempferol 3,7-dimethyl ether and quercetagetin 3,7,3’-trimethyl ether (chrysosplenol C), which are major flavonols isolated from the plant, were tested on prostate epithelial cells (PNT2), prostate cancer cells (DU145 and PC3), human keratinocytes (HaCaT), and melanoma cells (HTB140 and A375). Both flavonols demonstrated moderate cytotoxic activity against PC3 cells (IC50 = 59.5 µM and 46.6 µM, respectively). The remaining cell lines were less affected (IC50 > 150 µM).

Assessment of the Impacts of Centipeda minima (L.) on Cell Viability, and Osteogenic Differentiation of Mesenchymal Stem Cell Spheroids

Background and Objectives: Centipeda minima (L.) is a well-known and traditional pharmaceutical that has been utilized to treat different conditions controlling rhinitis, soothe pain, and decrease swelling. We assessed the impacts of Centipeda minima (L.) extricates (CMTs) on the osteogenic differentiation of cell spheroids made of human-bone-marrow-derived mesenchymal stem cells. Materials and Methods: Mesenchymal stem cells (MSCs) in spheroid 3D culture were generated and propagated in the presence of CMTs ranging from 0 to 1 μg/mL. Cell morphology was measured on Days 1, 3, 5, and 7. The quantitative cellular viability was evaluated on Days 1, 3, 5, and 7. Alkaline phosphatase activity assays were designed to measure the osteogenic differentiation of mesenchymal stem cell spheroids on Day 7. Alizarin Red S staining was performed to investigate the mineralization of cell spheroids on Days 7 and 14. Real-time polymerase chain reactions were used to measure the expression levels of RUNX2 and COL1A1 on Day 14. Western blot techniques were performed to identify the protein expression of Runt-related transcription factor 2 and type I collagen. Results: The control group’s mesenchymal stem cells displayed a spheroid shape. There was no noticeable change in morphology with the addition of CMTs at final concentrations of 0.001, 0.01, 0.1, and 1 μg/mL compared with the untreated (control) group. The application of CMTs did not induce a significant change in cell viability. The relative alkaline phosphatase activity values in the 0.001, 0.01, 0.1, and 1 μg/mL CMT groups were 114.4% ± 8.2%, 130.6% ± 25.3%, 87.8% ± 3.4%, and 92.1% ± 6.8%, respectively, considering a control of 100% (100.0% ± 17.9%). On Day 14, calcium deposits were clearly observed in each group. The relative values of Alizarin Red S staining in the 0.001, 0.01, 0.1, and 1 μg/mL CMT groups were 100.1% ± 8.9%, 105.9% ± 0.0%, 109.7% ± 19.1%, and 87.0% ± 40.9%, respectively, considering a control of 100% (100.0% ± 28.7%). The addition of CMT significantly increased RUNX2 expression in the 0.01 μg/mL group and COL1A1 in the 0.001 and 0.01 μg/mL groups. Normalization of protein expression showed that the addition of CMTs significantly increased type I collagen expression in the 0.001, 0.01, and 1 μg/mL groups. Conclusions: In conclusion, CMTs influence the osteogenic differentiation of bone-marrow-derived mesenchymal stem cells and the use of CMTs may positively influence the osteogenic differentiation of cell spheroids.

Brevilin A Ameliorates Imiquimod-Induced Psoriasis-like Dermatitis and Reduces Th17 Differentiation in Psoriasis Patients

Psoriasis is a predominantly Th17 cell-driven chronic autoinflammatory skin disorder. Brevilin A, a natural sesquiterpene lactone extracted from Centipeda minima, has been used as a traditional oriental medicine for allergic diseases for centuries. However, the effects of brevilin A on psoriasis have yet to be established. In this study, we investigated brevilin A to elucidate its potential effects on T cell activities in psoriasis, in animal models and patients. An imiquimod (IMQ)-induced psoriasis-like dermatitis murine model was utilized. Experimental mice were administered different doses of brevilin A (5, 10, 20 mg/kg respectively) for a duration of 5 days. Cutaneous manifestations were measured daily. Under hematoxylin and eosin (H&E) stain and immunohistochemistry (IHC), acanthosis and proinflammatory cytokine expression in the dorsal skin of mice were detected. Enzyme-linked immunosorbent assay (ELISA) was used for the measurement of IL-17A levels in serum samples. Naïve CD4+ T cells, isolated from mice spleen and lymph nodes and from peripheral blood mononuclear cells (PBMCs) of psoriatic patients, were used to evaluate the effects of brevilin A on Th17 differentiation. In brevilin A-treated mice, brevilin A significantly reduced skin redness and scaling; acanthosis as well as IL-6, IL-17A, and ki-67 expressions were downregulated in the dorsal skin, and serum levels of IL-17A were lowered. Brevilin A also inhibited Th17 differentiation. In conclusion, brevilin A demonstrated significant capability in ameliorating skin inflammation in IMQ-induced psoriasis-like dermatitis and could modulate Th17 differentiation. Therefore, brevilin A is potentially pharmacologically effective in the treatment of psoriasis.

Centipeda minima: An update on its phytochemistry, pharmacology and safety

ETHNOPHARMACOLOGICAL RELEVANCE

Centipeda minima (CM), the dried whole plant of Centipeda minima (L.) A. Braun and Aschers, has been used as a traditional Chinese medicinal herb for thousands of years for the treatments of rhinitis, sinusitis, cough and asthmatic diseases. This review aimed to evaluate the therapeutic potential of CM by summarizing its phytochemistry, pharmacology, clinical application and safety.

METHODS

This review summarizes the published studies on CM in the Chinese Pharmacopoeia and literature databases including PubMed, Web of Science, Baidu Scholar, Wiley and China Knowledge Resource Integrated Database (CNKI), as well as the research articles on the phytochemistry, pharmacology, clinical application and safety of CM.

RESULTS

A total of 191 compounds have been isolated and identified from CM, including terpenes, flavonoids, sterols, phenols, organic acids and volatile oils. In addition, the pharmacological effects of CM, such as anti-cancer, anti-inflammatory and anti-bacterial activities, have also been evaluated by both in vitro and in vivo studies. The signaling pathways and mechanisms of action underlying the anti-cancer effects of CM have been revealed. Clinical applications of CM mainly include rhinitis and sinusitis, gynecological inflammation, cough, as well as asthma.

CONCLUSION

CM is a medicinal herb that possesses many therapeutic effects. Cutting-edge technology and system biology could provide us a more comprehensive understanding of the therapeutic effects, constituting components and toxicity of CM, which are the prerequisites for its translation into therapeutics for various disease treatments.

Indigenous Uses, Phytochemical Analysis, and Anti-Inflammatory Properties of Australian Tropical Medicinal Plants

Australian tropical plants have been a rich source of food (bush food) and medicine to the first Australians (Aboriginal people), who are believed to have lived for more than 50,000 years. Plants such as spreading sneezeweed (Centipeda minima), goat’s foot (Ipomoea pes-caprae), and hop bush (Dodonaea viscosa and D. polyandra) are a few popular Aboriginal medicinal plants. Thus far, more than 900 medicinal plants have been recorded in the tropical region alone, and many of them are associated with diverse ethnomedicinal uses that belong to the traditional owners of Aboriginal people. In our effort to find anti-inflammatory lead compounds in collaboration with Aboriginal communities from their medicinal plants, we reviewed 78 medicinal plants used against various inflammation and inflammatory-related conditions by Aboriginal people. Out of those 78 species, we have included only 45 species whose crude extracts or isolated pure compounds showed anti-inflammatory properties. Upon investigating compounds isolated from 40 species (for five species, only crude extracts were studied), 83 compounds were associated with various anti-inflammatory properties. Alphitolic acid, Betulinic acid, Malabaric acid, and Hispidulin reduced proinflammatory cytokines and cyclooxygenase enzymes (COX-1 and 2) with IC₅₀ values ranging from 11.5 to 46.9 uM. Other promising anti-inflammatory compounds are Brevilin A (from Centipeda minima), Eupalestin, and 5′-methoxy nobiletin (from Ageratum conyzoides), Calophyllolide (from Calophyllum inophyllum), and Brusatol (from Brucea javanica). D. polyandra is one example of an Aboriginal medicinal plant from which a novel anti-inflammatory benzoyl ester clerodane diterpenoid compound was obtained (compound name not disclosed), and it is in the development of topical medicines for inflammatory skin diseases. Medicinal plants in the tropics and those associated with indigenous knowledge of Aboriginal people could be a potential alternative source of novel anti-inflammatory therapeutics.

Comparison of the Phytochemical Variation of Non-Volatile Metabolites within Mother Tinctures of Arnica montana Prepared from Fresh and Dried Whole Plant Using UHPLC-HRMS Fingerprinting and Chemometric Analysis

Arnica montana L. has been recognized for centuries as an herbal remedy to treat wounds and promote healing. It also has a long tradition of use in homeopathy. Depending on its medicinal utilization, standardization regulations allow different manufacturing processes, implying different raw materials, such as the whole arnica plant in its fresh or dried state. In this study, an untargeted metabolomics approach with UHPLC-HRMS/MS was used to cross-compare the phytochemical composition of mother tinctures of A. montana that were prepared from either fresh whole plant (fMT) matter or from oven-dried whole plant (dMT) matter. The multivariate data analysis showed significant differences between fMT and dMT. The dereplication of the HRMS and MS/MS spectra of the more discriminant compounds led to annotated quinic acid, dicaffeoyl quinic acids, ethyl caffeate, thymol derivatives and dehydrophytosphingosine, which were increased in fMT, while Amadori rearrangement products (ARP) and methoxyoxaloyl-dicaffeoyl quinic acid esters were enhanced in dMT. Neither sesquiterpene lactones nor flavonoids were affected by the drying process. This is the first time that a sphingosine, ethyl caffeate and ARP are described in A. montana. Moreover, putative new natural products were detected as 10-hydroxy-8,9-epoxy-thymolisobutyrate and an oxidized proline fructose conjugate, for which isolation and full structure elucidation will be necessary to verify this finding.

Anti-Helicobacter pylori Compounds from Oliveria decumbens Vent. through Urease Inhibitory In-vitro and In-silico Studies

Oliveria decumbens Vent. has been used by indigenous people of southwest Iran for treating peptic ulcers and gastrointestinal infections. This study aimed to investigate the antibacterial activity of Oliveria decumbens extract and fractions and to analyze the bioactive components of the fractions. Total plant extract and different fractions of Oliveria decumbens Vent. were prepared. Antibacterial activities were evaluated against the clinical strain of Helicobacter pylori and standard strains of Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, and Pseudomonas aeruginosa using agar dilution and disc diffusion methods. Phytochemical analysis of the fractions was performed using silica gel chromatography and 1D and 2D NMR spectroscopy. Moreover, the urease inhibitory effects of the isolated compounds were assessed in-vitro and in-silico. Three novel kaempferol derivatives and two thymol derivatives were isolated from Oliveria decumbens aerial parts, and the structures were determined by comparison with published data. The n-hexane fraction was found to exert the most significant anti-H. pylori activity with the minimum inhibitory concentration of 50 µg/mL. All fractions demonstrated antibacterial activity toward S. aureus. In-vitro urease inhibition assay showed that stigmasterol, tiliroside, and carvacrol were found to be the most potent enzyme inhibitors in the isolated compounds. Molecular interactions of the compounds with the active site of urease were supported by the molecular docking analysis. Novel bioactive compounds in Oliveria decumbens were described in this study. The antibacterial effects suggested the potential use of the compounds in pharmaceutical formulations inconsistent with the traditional use of the plant in the treatment of gastrointestinal infections.

Edible Bird's Nest: Recent Updates and Industry Insights Based On Laboratory Findings

Edible bird’s nest (EBN) is a traditional Chinese delicacy made of the saliva of swiftlets found in Southeast Asia. With increasing demands for EBN, quality control of EBN products is important for safe consumption. The processing steps are particularly important for efficient extraction of bioactive compounds. Geographical location, collection place, and harvesting season contribute to differences in nutritional contents in EBN. Concerns regarding presence of adulterant, chemical, and microbial contaminants in EBN as well as authentication and chemical composition measuring methods are discussed in this review. Recent discoveries of beneficial health functions of EBN in antimicrobial and antiviral actions, immunomodulation, cancer prevention and treatment, tissue regeneration, cardiometabolic maintenance, antioxidant action and neuroprotection are also reviewed. Our review provides an update on the recent research on EBN.

Hair Growth Stimulation Effect of Centipeda minima Extract: Identification of Active Compounds and Anagen-Activating Signaling Pathways

Centipeda minima (L.) A. Braun & Asch is a well-studied plant in Chinese medicine that is used for the treatment of several diseases. A recent study has revealed the effects of extract of Cetipeda minima (CMX) standardized by brevilin A in inducing hair growth. However, the mechanism of action of CMX in human hair follicle dermal papilla cells (HFDPCs) has not yet been identified. We aimed to investigate the molecular basis underlying the effect of CMX on hair growth in HFDPCs. CMX induced the proliferation of HFDPCs, and the transcript-level expression of Wnt family member 5a (Wnt5a), frizzled receptor (FZDR), and vascular endothelial growth factor (VEGF) was upregulated. These results correlated with an increase in the expression of growth-related factors, such as VEGF and IGF-1. Immunoblotting and immunocytochemistry further revealed that the phosphorylation of ERK and JNK was enhanced by CMX in HFDPCs, and β-catenin accumulated significantly in a dose-dependent manner. Therefore, CMX substantially induced the expression of Wnt signaling-related proteins, such as GSK phosphorylation and β-catenin. This study supports the hypothesis that CMX promotes hair growth and secretion of growth factors via the Wnt/β-catenin, ERK, and JNK signaling pathways. In addition, computational predictions of drug-likeness, together with ADME property predictions, revealed the satisfactory bioavailability score of CMX compounds, exhibiting high gastrointestinal absorption. We suggest that CMX could be used as a promising treatment for hair regeneration and minimization of hair loss.

Medicinal Plant Centipeda Minima: A Resource of Bioactive Compounds

BACKGROUND

Centipeda minima (the family Asteraceae) is an annual herbaceous plant native to the tropical regions, especially in eastern tropical Asia. C. minima is well-known in the list of medicinal plants with capacities in treatment of whooping cough, nasal allergy, malaria, and asthma. More than sixty reports on phytochemical and pharmacological aspects of this plant are now available, but a supportive review is insufficient.

OBJECTIVE

The current review aims to make a compilation of almost all of the isolated compounds from the title plant, together with their pharmacological activities.

METHODOLOGY

Centipeda minima is a meaningful keyword to search for previous references, while the reliable databases, such as Sci-Finder, Google Scholar, Pub Med, Science Direct, the Web of Science, Scopus, Bentham science, Taylor Francis, Springer, IOP Science were utilized at most.

CONCLUSION

More than one hundred secondary metabolites, classifying as terpenoids, flavonoids, mono-phenols, fatty acids, amides, and other types, were isolated from this plant. Among them, sesquiterpene lactones are dominant in either C. minima species or numerous plants of genus Centipeda. These phytochemical groups also possessed various biological results like anti-cancer, anti-bacteria, anti-allergy, anti-virus, anti-inflammation, and hepatoprotective activities. With many kinds of bioactive results such as anti-cancer and anti-inflammation, the use of C. minima plant extracts and isolated compounds for drug development seems to be a futuristic strategy.

Cytotoxic and Anti-Inflammatory Sesquiterpenes from the Whole Plants of Centipeda minima

Sixteen new sesquiterpene lactones (1-16) along with 13 known analogues (17-29) were isolated from the whole plants of Centipeda minima. The structures of 1-16 were delineated by the combination of NMR spectroscopic experiments, HRESIMS, single-crystal X-ray diffraction analyses, and ECD spectra. Compounds 23-26 showed potent cytotoxicity against Hela, HCT-116, and HepG2 cells with IC₅₀ values of 0.8-2.6, 0.4-3.3, and 1.1-2.6 μM, respectively. Compounds 8, 15, and 24 exhibited significant inhibitory activity on the production of nitric oxide in the lipopolysaccharide-activated RAW 264.7 mouse macrophage cell line, with IC₅₀ values ranging from 0.1 to 0.2 μM.

Anti-cancer Activity of Centipeda minima Extract in Triple Negative Breast Cancer via Inhibition of AKT, NF-κB, and STAT3 Signaling Pathways

Breast cancer is the most commonly diagnosed cancer in females worldwide. Estimates from the World Health Organization (WHO) International Agency for Research on Cancer, suggest that globally, there were around 2.1 million new breast cancer cases and 627,000 deaths due to breast cancer in 2018. Among the subtypes of breast cancer, triple negative breast cancer (TNBC) is the most aggressive and carries the poorest prognosis, largest recurrence, and lowest survival rate. Major treatment options for TNBC patients are mainly constrained to chemotherapy, which can be accompanied by severe side effects. Therefore, development of novel and effective anti-cancer drugs for the treatment of TNBC are urgently required. Centipeda minima is a well-known traditional Chinese herbal medicine that has historically been used to treat rhinitis, sinusitis, relieve pain, and reduce swelling. Recent studies have shown that Centipeda minima exhibited efficacy against certain cancers, however, to date, no studies have been conducted on its effects in breast cancer. Here, we aimed to investigate the anti-cancer activity of the total extract of Centipeda minima (CME), and its underlying mechanism, in TNBC. In MDA-MB-231, we found that CME could significantly reduce cell viability and proliferation, induce apoptosis and inhibit cancer cell migration and invasion, in a dose and time-dependent manner. We showed that CME may potentially act via inhibition of multiple signaling pathways, including the EGFR, PI3K/AKT/mTOR, NF-κB, and STAT3 pathways. Treatment with CME also led to in vitro downregulation of MMP-9 activity and inhibition of metastasis. Further, we demonstrated that CME could significantly reduce tumor burden in MDA-MB-231 xenograft mice, without any appreciable side effects. Based on our findings, CME is a promising candidate for development as a therapeutic with high efficacy against TNBC.

6-O-angeloylplenolin exerts neuroprotection against lipopolysaccharide-induced neuroinflammation in vitro and in vivo

Neuroinflammation is one of the critical events in neurodegenerative diseases, whereas microglia play an important role in the pathogenesis of neuroinflammation. In this study, we investigated the effects of a natural sesquiterpene lactone, 6-O-angeloylplenolin (6-OAP), isolated from the traditional Chinese medicine Centipeda minima (L.) A.Br., on neuroinflammation and the underlying mechanisms. We showed that treatment with lipopolysaccharide (LPS) caused activation of BV2 and primary microglial cells and development of neuroinflammation in vitro, evidenced by increased production of inflammatory cytokines TNF-α and IL-1β, the phosphorylation and nuclear translocation of NF-κB, and the transcriptional upregulation of COX-2 and iNOS, leading to increased production of proinflammatory factors NO and PGE₂. Moreover, LPS treatment induced oxidative stress through increasing the expression levels of NOX2 and NOX4. Pretreatment with 6-OAP (0.5−4 μM) dose-dependently attenuated LPS-induced NF-κB activation and oxidative stress, thus suppressed neuroinflammation in the cells. In a mouse model of LPS-induced neuroinflammation, 6-OAP (5−20 mg·kg⁻¹·d⁻¹, ip, for 7 days before LPS injection) dose-dependently inhibited the production of inflammatory cytokines, the activation of the NF-κB signaling pathway, and the expression of inflammatory enzymes in brain tissues. 6-OAP pretreatment significantly ameliorated the activation of microglia and astrocytes in the brains. 6-OAP at a high dose caused a much stronger antineuroinflammatory effect than dexamethansone (DEX). Furthermore, we demonstrated that 6-OAP pretreatment could inhibit LPS-induced neurite and synaptic loss in vitro and in vivo. In conclusion, our results demonstrate that 6-OAP exerts antineuroinflammatory effects and can be considered a novel drug candidate for the treatment of neuroinflammatory diseases.

Ethanol Extract of Centipeda minima Exerts Antioxidant and Neuroprotective Effects via Activation of the Nrf2 Signaling Pathway

Oxidative stress is implicated in the pathogenesis of neurodegeneration and other aging-related diseases. Previous studies have found that the whole herb of Centipeda minima has remarkable antioxidant activities. However, there have been no reports on the neuroprotective effects of C. minima, and the underlying mechanism of its antioxidant properties is unclear. Here, we examined the underlying mechanism of the antioxidant activities of the ethanol extract of C. minima (ECM) both in vivo and in vitro and found that ECM treatment attenuated glutamate and tert-butyl hydroperoxide (tBHP)-induced neuronal death, reactive oxygen species (ROS) production, and mitochondria dysfunction. tBHP-induced phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) and c-Jun N-terminal kinases (JNK) was reduced by ECM, and ECM sustained phosphorylation level of extracellular signal regulated kinase (ERK) in SH-SY5Y and PC12 cells. Moreover, ECM induced the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) and the upregulation of phase II detoxification enzymes, including heme oxygenase-1 (HO-1), superoxide dismutase-2 (SOD2), and NAD(P)H quinone oxidoreductase-1 (NQO-1) in both two cell types. In a D-galactose (D-gal) and aluminum muriate (AlCl₃)-induced neurodegenerative mouse model, administration of ECM improved the learning and memory of mice in the Morris water maze test and ameliorated the effects of neurodegenerative disorders. ECM sustained the expression level of postsynaptic density 95 (PSD95) and synaptophysin (SYN), activated the Nrf2 signaling pathway, and restored the levels of cellular antioxidants in the hippocampus of mice. In addition, four sesquiterpenoids were isolated from C. minima to identify the bioactive components responsible for the antioxidant activity of C. minima; 6-O-angeloylplenolin and arnicolide D were found to be the active compounds responsible for the activation of the Nrf2 signaling pathway and inhibition of ROS production. Our study examined the mechanism of C. minima and its active components in the amelioration of oxidative stress, which holds the promise for the treatment of neurodegenerative disease.

Antiviral Activity of the Sesquiterpene Lactones from Centipeda minima against Influenza a Virus in vitro

During the course of searching for antiviral agents from Chinese medicinal herbs, we found that the supercritical fluid extract (SFE) of Centipeda minima possessed good in vitro antiviral activity against influenza virus A/Puerto Rico/8/34 H1N1 (PR8). Bioassay-guided isolation and identification led to the isolation from this extract of seven pseudoguaianolides (1-7). These, as well as nine other sesquiterpene lactones (8-16) previously isolated from this herb were all tested for their anti-PR8 activity using both the cytopathogenic effect (CPE) reduction and cell counting kit 8 (CCK8) assays. As a result, eight pseudoguaianolides (1-8) possessing an α,β-unsaturated cyclopentenone moiety showed antiviral activity against PR8 to different extents. Of the active compounds, brevilin A (4) exhibited the strongest anti-PR8 activity, with an IC50 value much lower than that of the positive control ribavirin. Mechanistic study revealed that brevilin A affected the intracellular replication of PR8 via downregulating the expression of viral M2 protein. All these results suggest the potential application of the pseudoguaianolides containing an α,β-unsaturated cyclopentenone moiety (e.g. brevilin A) in the treatment of influenza virus infection.

Antioxidant Activity of Essential Oil Extracted by SC-CO₂ from Seeds of Trachyspermum ammi

Bcakground: Extracts obtained from natural sources such as plants are of immense importance for humans. Methods: Therefore this study was conducted to obtain essential oil from the seeds of T. ammi by conventional and non-conventional methods. Hydrodistillation (HD), Solvent Extraction (SE), Ultrasonication (US), and Supercritical Carbon-dioxide (SC-CO₂) extraction techniques were used to extract essential oil from the powdered seeds of T. ammi. A quality control method for each extracted oil was developed using HPTLC, FTIR, and GC-MS. The optimization process was carried out using fractional factorial design (FFD) under which three parameters were considered: pressure (150, 175, and 300 bar), temperature (25, 30, and 40 °C), and CO₂ flow rate (5, 10, 15 g/min). Results: The yield of essential oil obtained from the HD, SE, US, and SC-CO₂ methods were 1.20%, 1.82%, 2.30%, and 2.64% v/w, respectively. Antioxidant activity was determined by the DPPH and superoxide scavenging methods and the IC₅₀ (Inhibition Concentration) values of the T. ammi oil sample were found to be 36.41 and 20.55 µg mL⁻¹, respectively. Conclusion: The present paper reported that different extraction methods lead to different yields of essential oils and the choice of a suitable method is extremely important to obtain more preferred compounds. The yield was higher in the SC-CO₂ method and it is a sustainable and green extraction technique. Many important constituents were detected in analytical techniques. Antioxidant activities carried out showed that essential oil extracted from T. ammi seeds possess significant antioxidant activity.

Pharmacological Properties and Molecular Mechanisms of Thymol: Prospects for Its Therapeutic Potential and Pharmaceutical Development

Thymol, chemically known as 2-isopropyl-5-methylphenol is a colorless crystalline monoterpene phenol. It is one of the most important dietary constituents in thyme species. For centuries, it has been used in traditional medicine and has been shown to possess various pharmacological properties including antioxidant, free radical scavenging, anti-inflammatory, analgesic, antispasmodic, antibacterial, antifungal, antiseptic and antitumor activities. The present article presents a detailed review of the scientific literature which reveals the pharmacological properties of thymol and its multiple therapeutic actions against various cardiovascular, neurological, rheumatological, gastrointestinal, metabolic and malignant diseases at both biochemical and molecular levels. The noteworthy effects of thymol are largely attributed to its anti-inflammatory (via inhibiting recruitment of cytokines and chemokines), antioxidant (via scavenging of free radicals, enhancing the endogenous enzymatic and non-enzymatic antioxidants and chelation of metal ions), antihyperlipidemic (via increasing the levels of high density lipoprotein cholesterol and decreasing the levels of low density lipoprotein cholesterol and low density lipoprotein cholesterol in the circulation and membrane stabilization) (via maintaining ionic homeostasis) effects. This review presents an overview of the current in vitro and in vivo data supporting thymol's therapeutic activity and the challenges concerning its use for prevention and its therapeutic value as a dietary supplement or as a pharmacological agent or as an adjuvant along with current therapeutic agents for the treatment of various diseases. It is one of the potential candidates of natural origin that has shown promising therapeutic potential, pharmacological properties and molecular mechanisms as well as pharmacokinetic properties for the pharmaceutical development of thymol.

Iron-catalyzed asymmetric hydrosilylation of 1,1-disubstituted alkenes

The highly regio- and enantioselective iron-catalyzed anti-Markovnikov hydrosilylation of 1,1-disubstituted aryl alkenes was developed using iminopyridine oxazoline ligands to afford chiral organosilanes. Additional derivatization of these products lead to chiral organosilanols, cyclic silanes, phenol derivatives, and 3-substituted 2,3-dihydrobenzofurans.

Comparative effect of thymol or its glucose conjugate, thymol-β-D-glucopyranoside, on Campylobacter in avian gut contents

Campylobacter jejuni is an important human food-borne pathogen that can contaminate meat and poultry during processing. Consequently, strategies are sought to reduce the carriage of C. jejuni in food animals before they arrive at the abattoir. Thymol is a natural product that reduces survivability of Campylobacter in vitro, but its rapid absorption from the proximal alimentary tract limits its bactericidal efficacy in vivo. Thymol-β-D-glucopyranoside is more resistant to absorption than free thymol, but its administration to chickens has not been reported. In the present studies, 1 mM thymol-β-D-glucopyranoside was shown to exhibit near equal anti-Campylobacter activity as 1 mM thymol when incubated anaerobically in avian crop or cecal contents in vitro, resulting in reductions of 1.10-2.32 log10 colony forming units mL(-1) in C. jejuni concentrations after 24 h incubation. In a follow-up live animal study, oral administration of thymol-β-D-glucopyranoside, but not free thymol, significantly lowered (>10-fold) recovery of Campylobacter from the crop of market-aged broilers when compared to placebo-treated controls (n = 6 broilers/treatment). Neither thymol-β-D-glucopyranoside nor thymol affected recovery of Campylobacter from cecal contents of the treated broilers. These results indicate that rapid absorption or passage of free thymol from the crop precluded its anti-Campylobacter activity at this site and throughout the entire gastrointestinal tract. Conversely, lower recovery of Campylobacter from the crop of birds treated with thymol-β-D-glucopyranoside indicates this conjugate was retained and able to be hydrolyzed to biologically active free thymol at this site as intended, yet was not sufficiently protected to allow passage of efficacious amounts of the intact glycoside to the lower gut. Nevertheless, these results warrant further research to see if higher doses or encapsulation of thymol-β-D-glucopyranoside or similar glycosides may yield an efficacious additive to reduce carriage of Campylobacter as well as other pathogens throughout the avian gut.

Metabolite profiling of edible bird's nest using gas chromatography/mass spectrometry and liquid chromatography/mass spectrometry

RATIONALE

Edible bird's nest (EBN) is a renowned food item in the Chinese community due to the therapeutic effects claimed to be brought about by its consumption. However, very little scientific information has been revealed to support these claims. Thus, metabolite profiling was performed to identify the metabolites and to relate them to the medicinal properties of EBN. The study also aims to further extend the results to determine any possible differences when the EBNs are classified according to their coloration, countries or production sites.

METHODS

Extraction of the metabolites was performed via sonication of EBN with methanol and chloroform. Two analytical platforms, namely gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS), were utilized to detect the metabolites. This multi-analytical platform would provide a comprehensive coverage of the metabolites in EBN. GC/MS analysis was conducted in scan mode from m/z 50-650. On the other hand, LC/MS analysis was operated in both positive and negative ion mode from m/z 150-1000.

RESULTS

Metabolites were identified and their relationships with the medicinal properties of EBN were deduced. Classification with chemometrics illustrates that EBNs could be differentiated according to their coloration, countries and production sites. This differentiation was due to the environment where the EBNs are produced. Furthermore, GC/MS was demonstrated to be more suitable for classification as the processing methods of the EBNs did not cause a significant variation in the metabolites detected by GC/MS.

CONCLUSIONS

The overall findings suggest that the novel approach of metabolite profiling offers new insights to understanding EBN and provided evidence to support the medicinal properties of EBN. In addition, the success of classification of EBNs with metabolite profiling combining with chemometrics represents a paradigm shift in the quality control of this food item.

Helenalin attenuates alcohol-induced hepatic fibrosis by enhancing ethanol metabolism, inhibiting oxidative stress and suppressing HSC activation

A compound was isolated from Centipeda minima using bioassay-guided screening. The structure of this compound was elucidated based on its spectral data, and it was identified as helenalin. The hepatoprotective effect of helenalin was evaluated using a liver fibrosis model induced by intragastric administration with alcohol within 24 weeks in rats. The results revealed that helenalin significantly prevented alcohol-induced hepatic injury and fibrogenesis, as evidenced by the decrease in serum aminotransferase, the attenuation of histopathological changes, and the inhibition of the hepatic fibrosis indicators, such as hyaluronic acid, type III precollagen, laminin, hydroxyproline and collagen α type I. Mechanistically, studies showed that helenalin expedited ethanol metabolism by enhancing the alcohol and aldehyde dehydrogenase activities. Furthermore, helenalin alleviated lipid peroxidation, recruited the antioxidative defense system, inhibited CYP2E1 activity, and reduced the inflammatory mediators, including TGF-β1, TNF-α, IL-6 and IL-1β and myeloperoxidase, via down-regulation of NF-κB. Helenalin significantly decreased collagen deposition by reducing the profibrotic cytokines like transforming growth factor-β, platelet-derived growth factor-β and connective tissue growth factor, and promoted extracellular matrix degradation by modulating the levels of tissue inhibitor of matrix metalloproteinase-1 and matrix metalloproteinase-9. In addition, helenalin inhibited HSC activation as evidenced by the down-regulation of α-SMA and TGF-β levels. In conclusion, helenalin had a significant protective effect on chronic ethanol-induced hepatic fibrosis and may be a major bioactive ingredient of C. minima.

Structure, absolute configuration, and antidiarrheal activity of a thymol derivative from Ageratina cylindrica

The leaves of Ageratina cylindrica afforded a thymol derivative that was characterized by physical and spectroscopical methods as (8S)-8,9-epoxy-6-hydroxy-l0-benzoyloxy-7-oxothymol isobutyrate (1). The absolute configuration of 1 was established as 8S by vibrational circular dichroism spectroscopy in combination with density functional theory calculations and by evaluation of the Flack and Hooft X-ray parameters. Compound 1 showed weak antiprotozoal activity against Entamoeba histolytica and Giardia lamblia trophozoites and a high inhibitory effect on hyperpropulsive movement of the small intestine in rats.

Phenolic constituents from the roots of Mikania micrantha and their allelopathic effects

Four new thymol derivatives, 8,10-dihydroxy-9-benzoyloxythymol (1), 9-isobutyryloxy-10-hydroxythymol (2), 7,8,9,10-tetrahydroxythymol (3), and 7,8,10-trihydroxy-9-E-feruloyloxythymol (4), were isolated from the fresh roots of Mikania micrantha , along with 8,9,10-trihydroxythymol (5), 8,10-dihydroxy-9-acetoxythymol (6), 8,10-dihydroxy-9-isobutyryloxythymol (7), 8,10-dihydroxy-9-(2-methylbutyryloxy)thymol (8), 8,9-dehydro-10-hydroxythymol (9), 8-methoxy-9-hydroxythymol (10), ethyl caffeate (11), ethyl ferulate (12), 3,5-di-O-caffeoylquinic acid (13), and mikanin (14). Their structures were determined by spectroscopic methods. The known thymol derivatives (5-10) were obtained from the genus Mikania for the first time. Allelopathic effects of these compounds on Arabidopsis thaliana seeds were evaluated by a filter paper assay. After the treatment at 0.1 mM for 4 days, the seed germination rate with compound 8 was 48% and the inhibitory rates of shoot growth with compounds 1, 2, 7-10, and 12 were over 40%. The IC50 values of compounds 1 and 8 on shoot growth were 342.5 and 625 μM, respectively.

Antioxidant and anti-inflammatory activities of aqueous extract of Centipeda minima

ETHNOPHARMACOLOGICAL RELEVANCE

Centipeda minima (L.) is traditionally used in Chinese folk medicine for the treatments of rhinitis, sinusitis, relieving pain, reducing swelling, and treating cancer for a long history in Taiwan. However, there is no scientific evidence which supports the use in the literature.

AIM OF THE STUDY

The aim of this study was to evaluate the antioxidant and anti-inflammatory activities of the aqueous extract of Centipeda minima (ACM).

MATERIALS AND METHODS

The following activities were investigated: antioxidant activities [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), DPPH (1,1-diphenyl-2-picrylhydrazyl)], and anti-inflammatory [lipopolysaccharide (LPS) induced nitric oxide (NO) production in RAW264.7 macrophages and paw-edema induced by λ-carrageenan (Carr)]. We also investigated the anti-inflammatory mechanism of ACM via studies of the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) and the levels of malondialdehyde (MDA) in the edema paw. Serum NO, tumor necrosis factor α (TNF-α), and interleukin-1β (IL-1β) were also measured in vivo. In HPLC analysis, the fingerprint chromatogram of ACM was established.

RESULTS

ACM showed the highest TEAC and DPPH radical scavenging activities, respectively. ACM also had highest contents of polyphenol and flavonoid contents. We evaluated that ACM and the reference compound of protocatechualdehyde and caffeic acid decreased the LPS-induced NO production in RAW264.7 cells. Administration of ACM showed a concentration dependent inhibition on paw edema development after Carr treatment in mice. The anti-inflammatory effects of ACM could be via NO, TNF-α, and IL-1β suppressions and associated with the increase in the activities of antioxidant enzymes. Western blotting revealed that ACM decreased Carr-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expressions.

CONCLUSIONS

Anti-inflammatory mechanisms of ACM might be correlated to the decrease in the level of Malondialdehyde (MDA), iNOS, and COX-2 via increasing the activities of CAT, SOD, and GPx in the edema paw. Overall, the results showed that ACM demonstrated antioxidant and anti-inflammatory activity, which supports previous claims of the traditional use for inflammation and pain.

Supercritical fluid extraction assisted isolation of sesquiterpene lactones with antiproliferative effects from Centipeda minima

Pseudoguaianolide sesquiterpene lactones minimolides A (1), B (2), C (3) and D (4) and two guaianolide sesquiterpene lactones minimolides E (5) and F (6), along with seven known ones (7-13), were isolated from the supercritical fluid extract of Centipeda minima. The structures of these compounds were elucidated by extensive spectroscopic methods (IR, UV, HRESIMS, 1D-NMR and 2D-NMR), and the complete structure and stereochemistry of 1 was further confirmed by X-ray diffraction analysis. Compounds 1, 5-8,11 and 13 displayed inhibitory activity against human nasopharyngeal cancer cells (CNE) with IC(50) values ranging from 1.1 to 20.3 μM. Compound 13 containing both α-methylene-γ-lactone and α, β-unsaturated cyclopentenone moieties exhibited even stronger inhibitory activity than that of cisplatin (positive control) through cell cycle arrest at G2/M phase. Isolation of six sesquiterpene lactones from Centipeda minima highlighted the potential of supercritical fluid extraction for enrichment of minor constituents for phytochemical study.

Antiproliferative Effects of Volatile Oils from Centipeda minima on Human Nasopharyngeal Cancer CNE Cells

Volatile oils from Centipeda minima extracted by steam distillation (SD) and supercritical fluid extraction (SFE) were investigated for their antiproliferative effects on the human nasopharyngeal cancer CNE cells. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay results showed that CNE cells were more susceptible to the SFE oil than to the SD oil. The IC50 values of the SFE oil were 56.6, 8.7 and 5.2 μg/mL after 24-, 48- and 72-h of treatment, respectively, whereas those of the SD oil were 123.5 μg/mL (24 h), 97.1 μg/mL (48 h) and 83.3 μg/mL (72 h). Mechanistic investigation revealed that SFE oil induced CNE cell death via induction of apoptosis by regulating the expression of the Bcl-2 family of proteins, resulting in the dysfunction of mitochondria, leading to the release of cytochrome c into the cytosol, which then activated caspase-9, and subsequently cleaved caspases-3 and −7. This study provided strong evidence for the anti-NPC potential of the SFE oil from C. minima.

Two new terpene glucosides and antitumor agents from Centipeda minima

One new monoterpene glucoside minimaoside A (1) and one new sesquiterpene glucoside minimaoside B (2), together with four known terpenoids, were isolated from the whole plants of Centipeda minima (L.) A. Braun et Ashers. Their structures were determined by spectroscopic methods. Compounds 5 and 6 showed weak or moderate cytotoxic activity toward several tumor cell lines.