Study on Oleum cinnamomi Inhibiting Cutibacterium acnes and Its Covalent Inhibition Mechanism.

Oleum cinnamomi (OCM) is a volatile component of the Cinnamomum cassia Presl in the Lauraceae family, which displays broad-spectrum antibacterial properties. It has been found that OCM has a significant inhibitory effect against Cutibacterium acnes (C. acnes), but the precise target and molecular mechanism are still not fully understood. In this study, the antibacterial activity of OCM against C. acnes and its potential effect on cell membranes were elucidated. Metabolomics methods were used to reveal metabolic pathways, and proteomics was used to explore the targets of OCM inhibiting C. acnes. The yield of the OCM was 3.3% (w/w). A total of 19 compounds were identified, representing 96.213% of the total OCM composition, with the major constituents being phenylpropanoids (36.84%), sesquiterpenoids (26.32%), and monoterpenoids (15.79%). The main component identified was trans-cinnamaldehyde (85.308%). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of OCM on C. acnes were 60 µg/mL and 180 µg/mL, respectively. The modified proteomics results indicate that cinnamaldehyde was the main bioactive ingredient within OCM, which covalently modifies the ABC transporter adenosine triphosphate (ATP)-binding protein and nicotinamide adenine dinucleotide (NADH)-quinone oxidoreductase, hindering the amino acid transport process, and disrupting the balance between NADH and nicotinamide adenine dinucleoside phosphorus (NAD+), thereby hindering energy metabolism. We have reported for the first time that OCM exerts an antibacterial effect by covalent binding of cinnamaldehyde to target proteins, providing potential and interesting targets to explore new control strategies for gram-positive anaerobic bacteria.

Chlojaponilactone B Attenuates THP-1 Macrophage Pyroptosis by Inhibiting the TLR/MyD88/NF-κB Pathway.

Pyroptosis, an innate immune response, plays a crucial role in the pathological process of inflammatory diseases. Although pyroptosis blockade is considered a potential therapeutic strategy, no ideal candidate drug has been identified. The natural product Chojaponilactone B (CJB) has demonstrated anti-inflammatory effects, but its role in macrophage pyroptosis has not been studied. This study aimed to investigate the effect and mechanism of CJB in inhibiting macrophage pyroptosis. Using an LPS/ATP-induced THP-1 macrophage pyroptosis model, we found that CJB significantly inhibited pyroptosis and reduced the levels of NLRP3, caspase 1, N-GSDMD, and inflammatory cytokines IL-1ß and IL-18. RNA sequencing analysis revealed that CJB interfered with LPS/ATP-induced THP-1 macrophage gene expression, suggesting involvement in anti-inflammatory and anti-pyroptotic signaling pathways. Additionally, CJB suppressed LPS/ATP-induced elevations in TLRs, MyD88, pro-IL-1ß, and NF-κB and blocked NF-κB p65 nuclear translocation. In summary, CJB inhibits NLRP3 activation and macrophage pyroptosis through the TLR/MyD88/NF-κB pathway, providing important evidence for its development as a potential drug for treating pyroptosis-related inflammatory diseases.

(±)-Sarcanan A, a pair of new enantiomeric dihydrobenzofuran neolignans from the aerial parts of Sarcandra glabra.

(+)-Sarcanan A (1a) and (-)-Sarcanan A (1b), a pair of new dihydrobenzofuran neolignan enantiomers, together with six known compounds (2-7), were isolated from the aerial parts of Sarcandra glabra. Their structures were elucidated by spectroscopic analysis, and the absolute configurations of 1a and 1b were determined by analyses of the electronic circular dichroism (ECD) data. All compounds were evaluated for their inhibitory effects on the nitric oxide (NO) production induced by lipopolysaccharide (LPS) in RAW264.7 cells, and compounds 2-4 exhibited moderate inhibition against NO production.

Neuroprotective Effects of a New Derivative of Chlojaponilactone B against Oxidative Damaged Induced by Hydrogen Peroxide in PC12 Cells.

A new sesquiterpenoid (1) was obtained by hydrogenating Chlojaponilactone B. The structure of 1 was elucidated according to a combination of NMR, HRESIMS, and NOE diffraction data. The treatment of H2O2 in a PC12 cell model was used to evaluate the antioxidant activity of 1. An MMT assay showed that 1 had no cytotoxicity to the PC12 cell and rescued cell viability from the oxidative damage caused by H2O2. The treatment of 1 stabilized the mitochondria membrane potential (MMP), which decreased the intracellular ROS level and reduced cell apoptosis in the oxidative stress model. The activities of antioxidant enzyme superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) and the content of intracellular glutathione (GSH) were significantly enhanced after the treatment of 1. In addition, the results of qRT-PCR showed that 1 treatment minimized the cell injury by H2O2 via the up-regulation of the expression of nuclear factor erythroid 2 (Nrf2) and its downstream enzymes Heme oxygenase 1 (HO-1), glutamate cysteine ligase-modifier subunit (GCLm), and NAD(P)H quinone dehydrogenase 1 (Nqo1). Based on the antioxidant activity of 1, we speculated its potential as a therapeutic agent for some diseases induced by oxidative damage.

Metabolomics-Driven Exploration of the Antibacterial Activity and Mechanism of 2-Methoxycinnamaldehyde.

Methicillin-resistant Staphylococcus epidermidis (MRSE) is one of the most commonly found pathogens that may cause uncontrollable infections in immunocompromised and hospitalized patients. Compounds isolated from cinnamon such as cinnamaldehyde and cinnamic acid showed promising anti-oxidant, anti-tumor, and immunoregulatory effects; more importantly, these compounds also possess promising broad-spectrum antibacterial activity. In this study, the potential antibacterial activity of 2-methoxycinnamaldehyde (MCA), another compound in cinnamon, against MRSE was investigated. Combining the broth microdilution test, live/dead assay, and biofilm formation assay, we found MCA was able to inhibit the proliferation, as well as the biofilm formation of MRSE, indicating MCA could not only affect the growth of MRSE but also inhibit the pathogenic potential of this bacterium. Additionally, the results of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) demonstrated that MCA caused morphological changes and the leakage of DNA, RNA, and cellular contents of MRSE. Due to the close relationship between cell wall synthesis, ROS formation, and cell metabolism, the ROS level and metabolic profile of MRSE were explored. Our study showed MCA significantly increased the ROS production in MRSE, and the following metabolomics analysis showed that the increased ROS production may partially be due to the increased metabolic flux through the TCA cycle. In addition, we noticed the metabolic flux through the pentose phosphate pathway (PPP) was upregulated accompanied by elevated ROS production. Therefore, the alterations in cell metabolism and increased ROS production could lead to the damage of the cell wall, which in turn decreased the proliferation of MRSE. In conclusion, MCA seemed to be a promising alternative antimicrobial agent to control MRSE infections.

Antibacterial Activity of the Essential Oil From Litsea cubeba Against Cutibacterium acnes and the Investigations of Its Potential Mechanism by Gas Chromatography-Mass Spectrometry Metabolomics.

Cutibacterium acnes (C. acnes) is an anaerobic Gram-positive bacterium generally considered as a human skin commensal, but is also involved in different infections, such as acne and surgical infections. Although there are a variety of treatments, the side effects and the problem of bacterial drug resistance still limit their clinical usage. In this study, we found that essential oil (EO) distilled from fresh mature Litsea cubeba possessed promising antibacterial activity against C. acnes. In order to elucidate its potential mechanism, bacteriostatic activity test, Live/Dead kit assay, scanning electron microscope (SEM), transmission electron microscope (TEM), and metabolomics were employed. In addition, the content of adenosine triphosphate (ATP) in bacterium and the activities of key enzymes involved in critical metabolic pathways were detected using a variety of biochemical assays. The results showed that EO exhibited significant antibacterial activity against C. acnes at a minimum inhibitory concentration (MIC) of 400 µg/mL and a minimum bactericidal concentration (MBC) of 800 µg/mL, and EO could destroy C. acnes morphology and inhibit its growth. Moreover, results from our study showed that EO had a significant effect on the C. acnes normal metabolism. In total, 86 metabolites were altered, and 34 metabolic pathways related to the carbohydrate metabolism, energy metabolism, amino acid metabolism, as well as cell wall and cell membrane synthesis were perturbed after EO administration. The synthesis of ATP in bacterial cells was also severely inhibited, and the activities of key enzymes of the glycolysis and Wood-Werkman cycle were significantly affected (Pyruvate Carboxylase, Malate Dehydrogenase and Pyruvate kinase activities were decreased, and Hexokinase was increased). Taken together, these results illustrated that the bacteriostatic effect of EO against C. acnes by breaking the bacterial cell morphology and perturbing cell metabolism, including inhibition of key enzyme activity and ATP synthesis. The results from our study may shed new light on the discovery of novel drugs with more robust efficacy.

Purification, Structural Characterization and Immunomodulatory Effects of Polysaccharides from Amomumvillosum Lour. on RAW 264.7 Macrophages.

Amomum Villosum Lour. (A. villosum) is a folk medicine that has been used for more than 1300 years. However, study of the polysaccharides of A. villosum is seriously neglected. The objectives of this study are to explore the structural characteristics of polysaccharides from A. villosum (AVPs) and their effects on immune cells. In this study, the acidic polysaccharides (AVPG-1 and AVPG-2) were isolated from AVPs and purified via anion exchange and gel filtration chromatography. The structural characteristics of the polysaccharides were characterized by methylation, HPSEC-MALLS-RID, HPLC, FT-IR, SEM, GC-MS and NMR techniques. AVPG-1 with a molecular weight of 514 kDa had the backbone of → 4)-α-d-Glcp-(1 → 3,4)-ß-d-Glcp-(1 → 4)-α-d-Glcp-(1 →. AVPG-2 with a higher molecular weight (14800 kDa) comprised a backbone of → 4)-α-d-Glcp-(1 → 3,6)-ß-d-Galp-(1 → 4)-α-d-Glcp-(1 →. RAW 264.7 cells were used to investigate the potential effect of AVPG-1 and AVPG-2 on macrophages, and lipopolysaccharide (LPS) was used as a positive control. The results from bioassays showed that AVPG-2 exhibited stronger immunomodulatory activity than AVPG-1. AVPG-2 significantly induced nitric oxide (NO) production as well as the release of interleukin (IL)-6 and tumor necrosis factor alpha (TNF-α), and upregulated phagocytic capacities of RAW 264.7 cells. Real-time PCR analysis revealed that AVPG-2 was able to turn the polarization of macrophages to the M1 direction. These results suggested that AVPs could be explored as potential immunomodulatory agents of the functional foods or complementary medicine.

Reactive oxygen species altering the metabolite profile of the marine-derived fungus Dichotomomyces cejpii F31-1.

To investigate the influence of reactive oxygen species (ROS) on the secondary metabolites of the marine-derived fungus Dichotomomyces cejpii F31-1, hydrogen peroxide (H2O2) was added to the GPY culture medium. The HPLC chromatogram of the EtOAc extract of the culture broth was distinct from that of the H2O2 free GPY medium. Further study of the metabolites in the GPY medium with H2O2 resulted in the discovery of eight known compounds. Among them, (22E)-5α, 8α-epidioxyergosta-6, 22-dien-3ß-ol (2) and ergosta-4,6,8(14),22-tetraene-3-one (3) were present in the highest concentration, while ergosterol and diketopiperazines are abundant in the H2O2 free medium. Additionally, a new compound, dichocetide D (1) containing a chlorine element and a known ergosterol (10) were isolated from the H2O2 free medium. (22E)-5α, 8α-epidioxyergosta-6, 22-dien-3ß-ol (2) exhibited moderate cytotoxic activity against human prostate cancer cell line LNCaP-C4-2B.

Chloraserrtone A, a Sesquiterpenoid Dimer from Chloranthus serratus.

Chloraserrtone A (1), a new sesquiterpenoid dimer with two lindenane-type sesquiterpenoid monomers bridged by two six-membered rings, was obtained from Chloranthus serratus. A combination of UV, IR, NMR, HRESIMS, and X-ray diffraction data were used to elucidate the structure of 1. Compound 1 represents the first lindenane-type sesquiterpenoid dimer with extremely unique C-15-C-15', C-4-C-6', and C-6-C-11' linkages to form two six-membered rings between the monomeric units. A plausible biosynthesis toward chloraserrtone A is proposed. This new compound (1), together with the known lindenane dimers (2-11), were assessed for their inhibitory effects on lipopolysaccharide-induced NO production in RAW264.7 cells. Compound 6 showed activity with an IC50 value of 3.7 µM.

Three new cassane diterpenes from the seeds of Caesalpinia minax Hance.

Four fractions were prepared from the crude extract of Caesalpinia minax Hance and the inhibitory activity of nitric oxide (NO) production release of RAW 264.7 cells stimulated by lipopolysaccharide (LPS) was evaluated. The ethyl acetate (EtOAc) fraction showed obvious inhibitory effect. Bioassay-guided fractionation led to the isolation of three new cassane diterpenes, caesalmin X (1), caesalmin Y (2) and caesalmin Z (3), together with 19 known cassane diterpenoids (4-22). Their structures were mainly characterised on the basis of extensive spectroscopic analyses and comparison with reported data. Moreover, three compounds (20-22) which possessed furanditerpenoid 7,17-lactone structures, displayed moderate activities, with IC50 value of 29.85, 27.38 and 25.40 µM, respectively.

Solanerioside A, an unusual 14,15-dinor-cyclophytane glucoside from the leaves of Solanum erianthum.

Solanerioside A (1), the first example of a diterpenoid glucoside featuring a 14,15-dinor-cyclophytane scaffold, together with three known terpene glucosides (2-4) were isolated from the methanol extract of the leaves of Solanum erianthum (Solanaceae). The structure of 1 was mainly characterised on the basis of extensive spectroscopic analyses, especially from the 2D NMR spectra. In addition, the spectroscopic data of (6E, 10E)-5,12-dihydroxy-ß-nerolidol 5-O-ß-D-glucopyranoside (3) were reported for the first time. However, these compounds did not display obvious inhibition of LPS-induced NO release in RAW264.7 cells and anti-tumour activity against A549, HepG2, Hela and MCF-7 cells in vitro.

Chlojaponilactone B from Chloranthus japonicus: Suppression of Inflammatory Responses via Inhibition of the NF-κB Signaling Pathway.

Bioassay-guided fractionation of an ethanolic extract of Chloranthus japonicus led to the isolation of the known lindenane-type sesquiterpenoid chlojaponilactone B (1). This compound exhibited pronounced inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. Further anti-inflammatory assays showed that 1 suppressed the levels of some key inflammation mediators, such as iNOS, TNF-α, and IL-6, in a dose-dependent manner, and reduced the ear thickness and neutrophil infiltration in 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated mice. A mechanistic study revealed that compound 1 exerted its anti-inflammatory effects via the suppression of the NF-κB signaling pathway, which inhibited NF-κB-dependent transcriptional activity, IκBα phosphorylation, and p65 nuclear translocation. In contrast, chlojaponilactone B (1) was found to exert little influence on the MAPK signaling pathway.

Enantiomeric Neolignans and a Sesquiterpene from Solanum erianthum and Their Absolute Configuration Assignment.

One pair of new C-8-C-3'/C-7-O-C-4' linked neolignan enantiomers (1a/1b) and one new guaiane sesquiterpene (2) first featuring the 1(2),9(10)-conjugated double bond were isolated from the stems of Solanum erianthum (Solanceae). Their structures were characterized on the basis of extensive spectroscopic analyses, especially from their 2D nuclear magnetic resonance (NMR) spectra. The absolute configurations of 1a/2b were rigorously elucidated by electronic circular dichroism (ECD) experiments combined with the reversed helicity rule for the 2,3-dihydrobenzo[b]furan chromophore, and compound 2 is the first report on the sterochemical assignment of a guaiane sesquiterpene by using the allylic axial chirality rule for the conjugated diene chromophore in combination with the calculated ECD spectrum.

Two new glycosides isolated from Sapindus mukorossi fruits: effects on cell apoptosis and caspase-3 activation in human lung carcinoma cells.

Two new glycosides (1, 2) and two saponins (3, 4) were isolated from the fruits of Sapindus mukorossi Gaertn. The two glycosides were designated as sapindoside G (1) and 4'',4'''''-O-diacetylmukurozioside IIa (2). All four compounds exhibited inhibitory effects against A549 human lung adenocarcinoma cells with inhibition rates up to 69.2-83.3% at a concentration of 100 µg/mL. Flow cytometric analysis revealed that compounds 1-4 could suppress A549 cell growth by promoting cell apoptosis, which was related to the activation of caspase-3.

Diterpenoids from aerial parts of Flickingeria fimbriata and their nuclear factor-kappaB inhibitory activities.

Chemical investigation of the aerial parts of Flickingeria fimbriata (Bl.) Hawkes resulted in isolation of sixteen ent-pimarane diterpenoids, including five rare 16-nor-ent-pimarane diterpenoids, two 15,16-dinor-ent-pimarane diterpenoids and one ent-pimarane diterpenoid. Structures were mainly elucidated by extensive spectroscopic analysis, and their absolute configurations were unequivocally determined by the exciton chirality method, the modified Mosher's method, the CD experiments (including Snatzke's method) and chemical transformations, respectively. All the isolated compounds were screened for inhibitory effects on the nuclear factor-kappaB (NF-κB) in lipopolysaccharide (LPS) induced murine macrophage RAW264.7 cells, using a NF-κB-dependent luciferase reporter gene assay. Several of these compounds displayed comparable or even better activities than the positive control pyrrolidinedithiocarbamate (PDTC) (IC50=26.3 µM) with IC50 values in the range of 14.7-29.2 µM and structure-activity relationships are briefly proposed.

Solidification of floating organic drop liquid-phase microextraction cell fishing with gas chromatography-mass spectrometry for screening bioactive components from Amomum villosum Lour.

In this study, a novel solidification of floating organic drop liquid-phase microextraction cell fishing with gas chromatography-mass spectrometry (SFOD-LPME-CF-GC-MS) method was established and used to screen, isolate and analyze bioactive components from Amomum villosum Lour. extract. Through comparision of its effect on the models of normal cell and inflammatory cells, anti-inflammatory active components of essential oil from A. villosum Lour. were readily screened, and the components obtained are in agreement with related pharmacological articles. SFOD-LPME-CF-GC-MS was used to analyze the interaction of A. villosum Lour. extracts with normal and lipopolysaccharide-stimulated RAW264.7 macrophage cells. The effect of A. villosum Lour. essential oil extracts in the LPS-stimulated RAW264.7 model were also assessed in terms of cytotoxicity and nitric oxide production as an indication of bioactivity. Three potentially bioactive components were identified, demonstrating that SFOD-LPME-CF-GC-MS can be used successfully in the drug-screening process. This approach avoids the requirement for protein precipitation, but more importantly, generates a high concentration ratio, allowing analysis of trace components in traditional Chinese medicines. SFOD-LPME-CF-GC-MS is a simple, fast, effective and reliable method for the screening and analysis of bioactive components, and it can be extended to screen other bioactive components from TCMs.

A new bibenzyl derivative with nuclear factor-kappaB inhibitory activity from Schefflera arboricola (Araliaceae).

A new bibenzyl derivative (1), 4-acetoxy-3,5,3',4'-tetramethoxybibenzyl, along with eight known compounds (2-9), was isolated from the twigs and leaves of Schefflera arboricola (Araliaceae). The isolated compounds were elucidated mainly by means of one-dimensional, two-dimensional NMR and MS, and by comparison with the literature data. Compounds 2-5 and 7-9 are first reported from this plant. In the in vitro assays, compound 1 displayed moderate nuclear factor-kappaB inhibitory activity.

A new triterpenoid saponin and an oligosaccharide isolated from the fruits of Sapindus mukorossi.

A new triterpenoid saponin (1) and a new oligosaccharide (2), together with three known saponins (3-5), have been isolated from n-BuOH extract of the fruits of Sapindus mukorossi Gaertn. The structures were elucidated using detailed analysis of one- and two-dimensional nuclear magnetic resonance spectra along with their mass spectrometric data and the results of acid hydrolysis. Of the isolated compounds 1 and 3-5 displayed cytotoxic effects against human cancer cell lines in A-549 (lung carcinoma), MDA-231 (breast carcinoma) and PC-3 (prostatic carcinoma).

Thin-layer chromatographic identification of Chinese propolis using chemometric fingerprinting.

INTRODUCTION: Poplar tree gum has a similar chemical composition and appearance to Chinese propolis (bee glue) and has been widely used as a counterfeit propolis because Chinese propolis is typically the poplar-type propolis, the chemical composition of which is determined mainly by the resin of poplar trees. The discrimination of Chinese propolis from poplar tree gum is a challenging task. OBJECTIVE: To develop a rapid thin-layer chromatographic (TLC) identification method using chemometric fingerprinting to discriminate Chinese propolis from poplar tree gum. METHODS: A new TLC method using a combination of ammonia and hydrogen peroxide vapours as the visualisation reagent was developed to characterise the chemical profile of Chinese propolis. Three separate people performed TLC on eight Chinese propolis samples and three poplar tree gum samples of varying origins. Five chemometric methods, including similarity analysis, hierarchical clustering, k-means clustering, neural network and support vector machine, were compared for use in classifying the samples based on their densitograms obtained from the TLC chromatograms via image analysis. RESULTS: Hierarchical clustering, neural network and support vector machine analyses achieved a correct classification rate of 100% in classifying the samples. A strategy for TLC identification of Chinese propolis using chemometric fingerprinting was proposed and it provided accurate sample classification. CONCLUSION: The study has shown that the TLC identification method using chemometric fingerprinting is a rapid, low-cost method for the discrimination of Chinese propolis from poplar tree gum and may be used for the quality control of Chinese propolis.

[Expressions and correlations of let-7a and IL-6 in esophageal squamous cell carcinoma].

OBJECTIVE: To investigate the expressions of let-7a and IL-6 in esophageal squamous cell carcinoma (ESCC) tissues and to analyze their correlations. METHODS: The expression of let-7a in tumor tissues and matched adjacent non-tumor tissues of 40 ESCC patients was detected by stem-loop RT-PCR, and the expression of IL-6 was detected by quantitative real-time PCR (qRT-PCR) and immunohistochemical staining (SP method), respectively. RESULTS: Let-7a was underexpressed in ESCC tissues compared with matched non-tumor tissues (P<0.01); IL-6 mRNA was overexpressed in ESCC tissues compared with matched non-tumor tissues (P<0.01); the positive rate of IL-6 protein in ESCC tissues was significantly higher than that in non-tumor tissues (P<0.01). There was a negative relationship between the level of let-7a and IL-6 mRNA (r=-0.974; P<0.01), and the level of let-7a in IL-6 positive expression group was lower than that in IL-6 negative expression group (P<0.05). CONCLUSION: Let-7a is down-regulated and IL-6 is overexpressed in ESCC patients, suggesting that there is a significantly negative correlation between them.