Anti-inflammatory flavonoids from Cryptocarya chingii

On the use OF 1H-NMR chemical shifts and thermodynamic data for the prediction of the predominant conformation of organic molecules in solution: the example of the flavonoid rutin

Conformational analyses of organic compounds in solution still represent a challenge to be overcome. The traditional methodology uses the relative energies of the conformations to decide which one is most likely to exist in the experimental sample. The goal of this work was to deepen the approach of conformational analysis of flavonoid rutin (a well-known antioxidant agent) in DMSO solution. The methodology we used in this paper involves expanding the sample configuration space to a total of 44 possible geometries, using Molecular Dynamics (MD) simulations, which accesses structures that would hardly be considered with our chemical perception, followed by DFT geometry optimizations using the ωB97X-D/6-31G(d,p) - PCM level of theory. Spectroscopic and thermodynamic analyses were done, by calculating the relative energies and nuclear magnetic resonance (1H-NMR) chemical shifts, comparing the theoretical and experimental 1H-NMR spectra (DMSO-d 6) and evaluating Mean Absolute Error (MAE). The essence of this procedure lies in searching for patterns, like those found in traditional DNA tests common in healthcare. Here, the theoretical spectrum plays the role of the analyzed human sample, while the experimental spectrum acts as the reference standard. In solution, it is natural for the solute to dynamically alter its geometry, going through various conformations (simulated here by MD). However, our DFT/PCM results show that a structure named 32 with torsion angles ϕ 1 and ϕ 2 manually rotated by approx. 20° showed the best theoretical-experimental agreement of 1H-NMR spectra (in DMSO-d 6). Relative energies benchmarking involving 16 DFT functionals revealed that the ωB97X-D is very adequate for estimating energies of organic compounds with dispersion of charge (MAE < 1.0 kcal mol-1, using ab initio post-Hartree-Fock MP2 method as reference). To describe the stability of the conformations, calculations of Natural Bonding Orbitals (NBO) were made, aiming to reveal possible intramolecular hydrogen bonds that stabilize the structures. Since van der Waals (vdW) interactions are difficult to be identified by NBO donations, the Reduced Density Gradient (RDG) were calculated, which provides 2D plots and 3D surfaces that describe Non-Covalent Interactions (NCI). These data allowed us to analyze the effect of dispersion interactions on the relative stability of the rutin conformations. Our results strongly indicate that a combination of DFT (ωB97X-D)-PCM relative energies and NMR spectroscopic criterion is a more efficient strategy in conformational analysis of organic compounds in solution.

Unusual acetylated flavonol glucuronides, oxyphyllvonides A-H with renoprotective activities from the fruits of Alpinae oxyphylla

As a widely consumed spice and Traditional Chinese Medicine, Alpinae oxyphylla has been used to treat conditions such as diarrhea, ulcers, dementia, and enuresis. Fruits of A. oxyphylla were phytochemically studied and the bioactive constituents against renal fibrosis were identified. Eight previously undescribed acetylated flavonol glucuronides named oxyphyllvonides A-H (1-7 and 10), two known acetylated flavonol glucuronides (8 and 9), together with seven known flavone glycosides (11-17) were isolated from the fruits of A. oxyphylla. Among them, flavonol glucuronides were discovered in Zingiberaceae for the first time. The planar structures of 1-7 and 10 were determined using HRESIMS and extensive spectroscopic techniques (UV, IR, 1D-NMR, and 2D-NMR). The absolute configurations of the sugar moiety in these compounds were determined by using LC-MS analysis of acid-hydrolyzed derivatized monosaccharides. Biological evaluation showed that 7-10, 13, 14, 16 and 17 inhibit renal fibrosis in TGF-β1-induced kidney proximal tubular cells. In addition, 7, 8 and 14 were superior to nootkatone in inhibiting Fibronectin expression. The finding has significant relevance to our ongoing research on the anti-renal fibrosis activity of A. oxyphylla.

The Genus Cryptocarya: A Review on Phytochemistry and Pharmacological Activities

Cryptocarya (the laurel family) is a large genus of great economic plants found in tropics and subtropics. Plants of this genus are a rich resource of essential oils, and pharmacological compounds. An overview of phytochemistry and pharmacological aspect is not yet available. This review aims to establish insightful information on phytochemistry, and pharmacological values. The literature collection is based on keywords 'Cryptocarya', 'phytochemistry', and 'pharmacology' using a broad panel of scientific sources, such as Google Scholar, Sciencedirect, and Wiley. Since the 1950s, Cryptocarya plants have been the main object in various phytochemical studies, by which about 390 metabolite compounds were isolated. Alkaloids, α-pyrones, and flavonoids could be seen as the main classes of Cryptocarya isolates. Cryptocarya constituents displayed potential pharmacological values such as anti-inflammatory, antimicrobial, antioxidative, antiviral, vasorelaxant activities, especially cytotoxicity.

Honey on brain health: A promising brain booster

Since ancient times, honey has been employed in many aspects of everyday life, the most popular of which is as a natural sweetener. Honey is used not only as a nutritional product but also in health as a supplement and in various applications, especially related to brain booster health. Brain health is the capacity to carry out all mental functions necessary for cognition, such as learning and judging, utilizing language, and recalling. This review presents the current trend of research on honey, particularly the interest in underlying mechanisms related to brain booster health. A total of 34 original articles addressing brain health from the consumption of honey were analyzed. We identified four main brain health benefits, which are memory booster, neuroprotective effect, anti-stress, and anti-nociceptive potentials with the proposed underlying mechanism. A lot of attention has been paid to the role that honey plays in brain health research, with the goal of examining the link between honey and brain health as well as the mechanism underlying it, the findings from this review may be potentially beneficial to develop new therapeutic roles for honey to help determine the best and most promising to benefit and boost overall brain health.

Comprehensive Review of Recent Advances in Chiral A-Ring Flavonoid Containing Compounds: Structure, Bioactivities, and Synthesis

Flavonoids are a group of natural polyphenolic substances that are abundant in vegetables, fruits, grains, and tea. Chiral A-ring-containing flavonoids are an important group of natural flavonoid derivatives applicable in a wide range of biological activities such as, cytotoxic, anti-inflammatory, anti-microbial, antioxidant, and enzyme inhibition. The desirable development of chiral A-ring-containing flavonoids by isolation, semi-synthesis or total synthesis in a short duration proves their great value in medicinal chemistry research. In this review, the research progress of chiral A-ring-containing flavonoids, including isolation and extraction, structural identification, pharmacological activities, and synthetic methods, is comprehensively and systematically summarized. Furthermore, we provide suggestions for future research on the synthesis and biomedical applications of flavonoids.

Fatty acid acylated flavonol glycosides from the seeds of Nephelium lappaceum and their nitric oxide suppression activity

Five undescribed fatty acid esters of flavonol glycosides, nephelosides A-E, along with eight known compounds, were isolated from the seeds of Nephelium lappaceum L. The structures were elucidated by extensive analysis of spectroscopic data in combination with GC-MS analysis. Potency of compounds toward nitric oxide suppression was assessed by monitoring the inhibition of lipopolysaccharide-stimulated nitric oxide production in J744.A1 macrophage cells. Nepheloside D, kaempferol and kaempferol 7-O-α-L-rhamnopyranoside showed significant activity with IC₅₀ values of 26.5, 11.6 and 12.0 μM, respectively.

The response of cecal microbiota to inflammatory state induced by Salmonella enterica serovar Enteritidis

By combining the experiments of reciprocal crosses of chicken infected with Salmonella enterica serovar Enteritidis (S. Enteritidis), we focused on the common response of cecal microbiota to an inflammatory state in respect of transcriptome and microbiome. The inoculation of S. Enteritidis improved the microbial diversity and promoted the microbiota evolution in our infection model. Correlation analysis between bacteria and inflammation-related genes showed that some intestinal microorganisms were “inflammophile” and thrived in an inflamed environment. The global function of cecal microbiome was to maintain the homeostasis likely by the up-regulation of microbial metabolism pathway in bacitracin, putrescine, and flavonoids production, although the bacitracin may affect the symbiotic bacteria Enterococcus. The action of S. Enteritidis had close relationships with multiple inflammation-related genes, including the genes PTAFR, LY96, and ACOD1 which proteins are related to the binding and tolerance of LPS, and the genes IL-18, IL-18R1 and IL-18RAP which products can form a functional complex and transmit IL-18 pro-inflammatory signal. Additionally, the infection of S. Enteritidis aroused the transcription of EXFABP, which protein has a potential to sequestrate the siderophore and might cause the decline of Escherichia-Shigella and Enterococcus. S. Enteritidis can escape from the sequestrating through the salmochelin, another kind of siderophore which cannot be recognized by EXFABP. Probably by this way, S. Enteritidis competed with the symbiotic bacteria and edged out the niches. Our research can help to understand the interplay between host, pathogen, and symbiotic bacteria.

Cryptocaryoic acids A - C: New phenyl alkyl acids isolated from the leaves of Australian rainforest plant Cryptocarya mackinnoniana

Phytochemical investigation of the leaves of the Australian rainforest tree Cryptocarya mackinnoniana led to the discovery of three new oxygenated phenyl alkyl acids, cryptocaryoic acids A - C and two known compounds, cryptocaryone and 2',6'-dihydroxy-4'-methoxychalcone. The structures of all the compounds were determined by detailed spectroscopic analysis. Mosher's analysis was used for absolute stereochemistry determination at C-11, while the remaining stereochemistry determination of the one remaining stereocenter C-13 was based on NOESY correlations. All compounds isolated were also evaluated for their anti-inflammatory properties by assessing their inhibitory effects on LPS and interferon-γ induced nitric oxide (NO) production and TNF- α release in RAW 264.7 macrophages. The new cryptocaryoic acids exhibited weak to moderate anti-inflammatory activity (NO inhibition) ranging from (18.4-56 μM).

Complex Flavanones from Cryptocarya metcalfiana and Structural Revision of Oboflavanone A

Nine new complex flavanones, cryptometcones A-I (1-9), along with four known analogues, were isolated from Cryptocarya metcalfiana. The structures of 1-9 including their absolute configurations were elucidated by spectroscopic data analysis and electronic circular dichroism (ECD) calculations. In addition, the structure of oboflavanone A was revised, while the absolute configurations of oboflavanone B, cryptoflavanone C, and cryptoflavanone D were determined, according to their spectroscopic data. Compounds 3-5, 8, and 9 exhibited cytotoxicity against the HCT-116 cancer cell line.

Two Novel Flavonoids and Cytotoxicity Evaluation from Cryptocarya yunnanensis

Two new flavonoids, cryunchalcone (1) and cryptoyunnanone I (2), were isolated from the leaves and twigs of Cryptocarya yunnanensis. Their structures were elucidated by the detailed spectroscopic data analysis and electronic circular dichroism (ECD) calculations. Cryunchalcone (1) is a biflavonoid constructed by a dihydrochalcone coupled with a chalcone through an unprecedented C-2''-C-6 linkage. Cryptoyunnanone I (2) is a unique complex flavanone bearing a phenylpropanoid moiety.

Water-Mediated ortho-Carboxymethylation of Aryl Ketones under Ir(III)-Catalytic Conditions: Step Economy Total Synthesis of Cytosporones A-C

An expeditious Ir(III)-catalyzed carboxymethylation of aryl ketone with diazotized Meldrum's acid has been developed in aqueous medium. Flavanone and chromanone were also found to be facile substrates with the developed catalytic system. Mechanistic studies revealed the active catalytic species and the role of water in the reaction process as hydroxy and proton sources. Employing the developed method, total synthesis of cytosporone A was achieved in two steps and that of cytosporones B-C was achieved in three steps starting from resorcinol.

Bioinspired syntheses of cryptoflavanones C and D, oboflavanones A and B, and cryptoyunnanones G and H enabled by an acid-triggered cascade sequence

Collective total syntheses of oboflavanones A-B, cryptoflavanones C-D, and cryptoyunnanones G-H via a bioinspired acid-triggered olefin isomerization/hemiacetalization/dehydration/formal [3 + 3]-type cycloaddition cascade process are presented.

Pinocembrin flavanone inhibits cell viability in PC-3 human prostate cancer by inducing cellular apoptosis, ROS production and cell cycle arrest

The main purpose of the present study was to evaluate the antitumor effects of pinocembrin in human prostate cancer cells (PC-3) along with investigating its effects on cell apoptosis, endogenous ROS production and cell cycle. MTT assay and clonogenic assays were used to study the effects on cell viability and cancer colony formation, respectively. Fluorescence microscopy along with Western blotting was used to study apoptotic effects induced by pinocembrin. Flow cytometry was used to study effects on ROS production and cell cycle phase distribution. Results indicated that pinocembrin promoted inhibition cell proliferation along with reducing cancer colony formation of PC-3 cells in a dose-dependent manner. Pinocembrin induced regulatory effects over expressions of caspase-3, caspase-9, Bax and Bcl-2, thereby promoting apoptotic cell death in PC-3 cells. It also led to the dose-dependent G0/G1 cell cycle arrest. In conclusion, pinocembrin exhibits strong anticancer effects in human prostate cancer cells mediated via apoptosis, endogenous ROS production and G0/G1 cell cycle arrest.

Pinocembrin Promotes OPC Differentiation and Remyelination via the mTOR Signaling Pathway

The exacerbation of progressive multiple sclerosis (MS) is closely associated with obstruction of the differentiation of oligodendrocyte progenitor cells (OPCs). To discover novel therapeutic compounds for enhancing remyelination by endogenous OPCs, we screened for myelin basic protein expression using cultured rat OPCs and a library of small-molecule compounds. One of the most effective drugs was pinocembrin, which remarkably promoted OPC differentiation and maturation without affecting cell proliferation and survival. Based on these in vitro effects, we further assessed the therapeutic effects of pinocembrin in animal models of demyelinating diseases. We demonstrated that pinocembrin significantly ameliorated the progression of experimental autoimmune encephalomyelitis (EAE) and enhanced the repair of demyelination in lysolectin-induced lesions. Further studies indicated that pinocembrin increased the phosphorylation level of mammalian target of rapamycin (mTOR). Taken together, our results demonstrated that pinocembrin promotes OPC differentiation and remyelination through the phosphorylated mTOR pathway, and suggest a novel therapeutic prospect for this natural flavonoid product in treating demyelinating diseases.

Cryptoyunnanones A-H, Complex Flavanones from Cryptocarya yunnanensis

Eight new complex flavanones with a novel linkage, cryptoyunnanones A-H (1-8), together with four known α-pyrones, were isolated from the leaves and twigs of Cryptocarya yunnanensis. The structures of 1-8 including their absolute configurations were characterized by spectroscopic data analysis and single-crystal X-ray crystallography. Plausible biosynthetic pathways for the formation of compounds 1-8 were proposed. Compounds 1-4 exhibited cytotoxicity against HCT-116, MDA-MB-231, and PC-3 cancer cells with IC₅₀ values from 6.4 to 9.1 μM.

Protective and therapeutic effects of the flavonoid "pinocembrin" in indomethacin-induced acute gastric ulcer in rats: impact of anti-oxidant, anti-inflammatory, and anti-apoptotic mechanisms

Peptic ulcer including gastric and duodenal ulcers is a common gastro-intestinal disorder worldwide, associated with a significant mortality due to bleeding and perforation. Numerous efforts are being exerted to look for natural drugs that lack the potential side effects but still keep beneficial effects for treatment and/or prevention of gastric ulcer. Pinocembrin (PINO) is a natural flavonoid retaining anti-microbial, anti-oxidant, and anti-inflammatory activities. The present study was conducted to investigate the protective and therapeutic effects of PINO against indomethacin (INDO)-induced gastric ulcer in rats and the possible underlying mechanisms. PINO (25 and 50 mg/kg) promoted mucus secretion, decreased ulcer index, and inhibited histopathological changes induced by INDO. Further investigation of possible mechanisms showed that PINO significantly attenuated INDO-induced oxidative and inflammatory responses in both doses when administrated before or after ulcer induction. PINO downregulated mRNA expression level of p38-mitogen-activated protein kinase (p38-MAPK) which subsequently inhibited NF-κB activation and inflammatory cytokine release including tumor necrosis factor-α (TNF-α) and interleukin-1beta (IL-1β). Additionally, PINO inhibited apoptotic activity which was confirmed by downregulation of caspase-3 transcription. The current results demonstrated the promising therapeutic activity of PINO against INDO-induced gastric ulcer due to-at least partly-its anti-oxidant, anti-inflammatory, and anti-apoptotic effects.

Essential oil composition of three Cryptocarya species from Malaysia

Cryptocarya species are mainly distributed in Africa, Asia, Australia and South America, widely used in traditional medicines for the treatment of skin infections and diarrhea. The present investigation reports on the extraction by hydrodistillation and the chemical composition of three Cryptocarya species (Cryptocarya impressa, Cryptocarya infectoria, and Cryptocarya rugulosa) essential oils from Malaysia. The chemical composition of these essential oils was fully characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of 51 components were identified in C. impressa, C. infectoria, and C. rugulosa essential oils representing 91.6, 91.4, and 83.0% of the total oil, respectively. The high percentages of α-cadinol (40.7%) and 1,10-di-epi-cubenol (13.4%) were found in C. impressa oil. β-Caryophyllene (25.4%) and bicyclogermacrene (15.2%) were predominate in C. infectoria oil. While in C. rugulosa oil, bicyclogermacrene (15.6%), δ-cadinene (13.8%), and α-copaene (12.3%) were predominate. To the best of our knowledge, there is no report on the essential oil composition of these three species.

Determination of Anticancer Zn(II)-Rutin Complex Structures in Solution through Density Functional Theory Calculations of 1H NMR and UV-VIS Spectra

Coordination compounds formed by flavonoid ligands are recognized as promising candidates as novel drugs with enhanced antioxidant and anticancer activity. Zn(II)-Rutin complexes have been described in the literature and distinct coordination modes proposed based on ¹H NMR/MS and IR/UV-VIS experimental spectroscopic data: 1:1/1:2 (Zn(II) binding to A-C rings) and 2:1 (Zn(II) binding to A-C-B rings) stoichiometry. Aiming to clarify these experimental findings and provide some physical insights into the process of complex formation in solution, we carried out density functional theory calculations of NMR and UV-VIS spectra for 25 plausible Zn(II)-Rutin molecular structures including solvent effect using the polarizable continuum model approach. The studied complexes in this work have 1:1, 1:2, 2:1, and 3:1 metal-ligand stoichiometry for all relevant Zn(II)-Rutin configurations. The least deviation between theoretical and experimental spectroscopic data was used as an initial criterion to select the probable candidate structures. Our theoretical spectroscopic results strongly indicate that the experimentally suggested modes of coordination (1:2 and 2:1) are likely to exist in solution, supporting the two distinct experimental findings in DMSO and methanol solution, which may be seen as an interesting result. Our predicted 1:2 and 2:1 metal complexes are in agreement with the experimental stoichiometry; however, they differ from the proposed structure. Besides the prediction of the coordination site and molecular structure in solution, an important contribution of this work is the determination of the OH-C5 deprotonation state of rutin due to metal complexation at the experimental conditions (pH = 6.7 and 7.20). We found that, in the two independent synthesis of metal complexes, distinct forms of rutin (OH-C5 and O^(-)-C5) are present, which are rather difficult to be assessed experimentally.

Spiro[3.5]nonenyl Meroterpenoid Lactones, Cryptolaevilactones G-L, an Ionone Derivative, and Total Synthesis of Cryptolaevilactone M from Cryptocarya laevigata

A CH3OH-CH2Cl2 (1:1) extract (N025439) of the leaves and twigs of Cryptocarya laevigata furnished eight new compounds, 1-8. Based on extensive 1D and 2D NMR spectroscopic data examination, the new δ-lactone derivatives 1-6 are monoterpene-polyketide hybrids containing a unique spiro[3.5]nonenyl moiety. Their trivial names, cryptolaevilactones G-L, follow those of the related known meroterpenoids cryptolaevilactones A-F. Cryptolaevilactone L (6) contains 11,12-cis-oriented substituents, while the other cryptolaevilactones contain trans-oriented groups. The structure of the linear δ-lactone 7, cryptolaevilactone M, was characterized from various spectroscopic data analysis, and the absolute configuration was determined by total synthesis through stereoselective allylation and Grubbs olefin metathesis. Compound 8 was elucidated to be an ionone derivative with a 3,4-syn-diol functionality.

Advances in Biosynthesis, Pharmacology, and Pharmacokinetics of Pinocembrin, a Promising Natural Small-Molecule Drug

Pinocembrin is one of the most abundant flavonoids in propolis, and it may also be widely found in a variety of plants. In addition to natural extraction, pinocembrin can be obtained by biosynthesis. Biosynthesis efficiency can be improved by a metabolic engineering strategy and a two-phase pH fermentation strategy. Pinocembrin poses an interest for its remarkable pharmacological activities, such as neuroprotection, anti-oxidation, and anti-inflammation. Studies have shown that pinocembrin works excellently in treating ischemic stroke. Pinocembrin can reduce nerve damage in the ischemic area and reduce mitochondrial dysfunction and the degree of oxidative stress. Given its significant efficacy in cerebral ischemia, pinocembrin has been approved by China Food and Drug Administration (CFDA) as a new treatment drug for ischemic stroke and is currently in progress in phase II clinical trials. Research has shown that pinocembrin can be absorbed rapidly in the body and easily cross the blood-brain barrier. In addition, the absorption/elimination process of pinocembrin occurs rapidly and shows no serious accumulation in the body. Pinocembrin has also been found to play a role in Parkinson's disease, Alzheimer's disease, and specific solid tumors, but its mechanisms of action require in-depth studies. In this review, we summarized the latest 10 years of studies on the biosynthesis, pharmacological activities, and pharmacokinetics of pinocembrin, focusing on its effects on certain diseases, aiming to explore its targets, explaining possible mechanisms of action, and finding potential therapeutic applications.

Structural Determination of Antioxidant and Anticancer Flavonoid Rutin in Solution through DFT Calculations of 1H NMR Chemical Shifts

As the knowledge of the predominant molecular structure of antioxidant and anticancer flavonoid rutin in solution is very important for understanding the mechanism of action, a quantum chemical investigation of plausible rutin structures including solvent effects is of relevance. In this work, DFT calculations were performed to find possible minimum energy structures for the rutin molecule. ¹H NMR chemical shift DFT calculations were carried out in DMSO solution using the polarizable continuum model (PCM) to simulate the solvent effect. Analysis of the experimental and theoretical ¹H NMR chemical shift profiles offers a powerful fingerprint criterion to determine the predominant molecular structure in solution. Therefore, our aim is to find the best match between experimental (in DMSO‐d) and theoretical (PCM–DMSO) ¹H NMR spectrum profiles. Among 34 optimized structures located on the potential energy surface, we found that structure 32, with a B‐ring deviated 30° from a planar configuration (geometry usually assumed for polyphenols), showed an almost perfect agreement with experimental the ¹H NMR pattern when compared to the corresponding fully optimized planar geometry. This structure is also predicted as the global minimum based on room‐temperature Gibbs free energy calculations in solution and, therefore, should be experimentally observed. This is new and valuable structural information regarding structure–activity relationship studies, and such information is hard to obtain by experimentalists without the aid of the X‐ray diffraction technique.

Bioactive flavonoids in medicinal plants: Structure, activity and biological fate

Flavonoids, a class of polyphenol secondary metabolites, are presented broadly in plants and diets. They are believed to have various bioactive effects including anti-viral, anti-inflammatory, cardioprotective, anti-diabetic, anti-cancer, anti-aging, etc. Their basic structures consist of C₆-C₃-C₆ rings with different substitution patterns to produce a series of subclass compounds, and correlations between chemical structures and bioactivities have been studied before. Given their poor bioavailability, however, information about associations between structure and biological fate is limited and urgently needed. This review therefore attempts to bring some order into relationships between structure, activity as well as pharmacokinetics of bioactive flavonoids.

(-)-Neocaryachine, an Antiproliferative Pavine Alkaloid from Cryptocarya laevigata, Induces DNA Double-Strand Breaks

Twelve benzylisoquinoline alkaloids, including pavine and phenanthroindolizidine types, were isolated from a MeOH/CH₂Cl₂ extract of Cryptocarya laevigata (stem bark) through bioactivity-guided fractionation for antitumor effects. Selected compounds were evaluated for antiproliferative activity against five human tumor cell lines, including a multidrug-resistant subline. Since more common 2,3,8,9-tetrasubstituted pavine alkaloids, such as crychine (3), exhibit very mild or no cytotoxicity, this compound type has not been well investigated for antitumor activity. Thus, this report is the first discovery of a 7-hydroxylated pavine alkaloid, (-)-neocaryachine (1), to demonstrate strong antiproliferative activity, with IC₅₀ values of 0.06 to 0.41 μM against five tested tumor cell lines, including an MDR subline. Further mechanism of action studies revealed that 1 impacts the cellular S-phase by inducing DNA double-strand breaks.

Antiproliferation of Cryptocarya concinna-derived cryptocaryone against oral cancer cells involving apoptosis, oxidative stress, and DNA damage

Background

Cryptocarya-derived crude extracts and their compounds have been reported to have an antiproliferation effect on several types of cancers but their impact on oral cancer is less well understood.

Methods

We examined the cell proliferation effect and mechanism of C. concinna-derived cryptocaryone (CPC) on oral cancer cells in terms of cell viability, apoptosis, reactive oxygen species (ROS), mitochondrial depolarization, and DNA damage.

Results

We found that CPC dose-responsively reduced cell viability of two types of oral cancer cells (Ca9-22 and CAL 27) in MTS assay. The CPC-induced dose-responsive apoptosis effects on Ca9-22 cells were confirmed by flow cytometry-based sub-G1 accumulation, annexin V staining, and pancaspase analyses. For oral cancer Ca9-22 cells, CPC also induced oxidative stress responses in terms of ROS generation and mitochondrial depolarization. Moreover, γH2AX flow cytometry showed DNA damage in CPC-treated Ca9-22 cells. CPC-induced cell responses in terms of cell viability, apoptosis, oxidative stress, and DNA damage were rescued by N-acetylcysteine pretreatment, suggesting that oxidative stress plays an important role in CPC-induced death of oral cancer cells.

Conclusions

CPC is a potential ROS-mediated natural product for anti-oral cancer therapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-016-1073-5) contains supplementary material, which is available to authorized users.

Transcriptome-enabled discovery and functional characterization of enzymes related to (2S)-pinocembrin biosynthesis from Ornithogalum caudatum and their application for metabolic engineering

Background

(2S)-Pinocembrin is a chiral flavanone with versatile pharmacological and biological activities. Its health-promoting effects have spurred on research effects on the microbial production of (2S)-pinocembrin. However, an often-overlooked salient feature in the analysis of microbial (2S)-pinocembrin is its chirality.

Results

Here, we presented a full characterization of absolute configuration of microbial (2S)-pinocembrin from engineered Escherichia coli. Specifically, a transcriptome-wide search for genes related to (2S)-pinocembrin biosynthesis from Ornithogalum caudatum, a plant rich in flavonoids, was first performed in the present study. A total of 104,180 unigenes were finally generated with an average length of 520 bp. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway mapping assigned 26 unigenes, representing three enzyme families of 4-coumarate:coenzyme A ligase (4CL), chalcone synthase (CHS) and chalcone isomerase(CHI), onto (2S)-pinocembrin biosynthetic pathway. A total of seven, three and one full-length candidates encoding 4CL, CHS and CHI were then verified by reverse transcription polymerase chain reaction, respectively. These candidates were screened by functional expression in E. coli individual or coupled multienzyme reaction systems based on metabolic engineering processes. Oc4CL1, OcCHS2 and OcCHI were identified to be bona fide genes encoding respective pathway enzymes of (2S)-pinocembrin biosynthesis. Then Oc4CL1, OcCHS2 and MsCHI from Medicago sativa, assembled as artificial gene clusters in different organizations, were used for fermentation production of (2S)-pinocembrin in E. coli. The absolute configuration of the resulting microbial pinocembrin at C-2 was assigned to be 2S-configured by combination of retention time, UV spectrum, LC–MS, NMR, optical rotation and circular dichroism spectroscopy. Improvement of (2S)-pinocembrin titres was then achieved by optimization of gene organizations, using of codon-optimized pathway enzymes and addition of cerulenin for increasing intracellular malonyl CoA pools. Overall, the optimized strain can produce (2S)-pinocembrin of 36.92 ± 4.1 mg/L.

Conclusions

High titre of (2S)-pinocembrin can be obtained from engineered E. coli by an efficient method. The fermentative production of microbial (2S)-pinocembrin in E. coli paved the way for yield improvement and further pharmacological testing.

Electronic supplementary material

The online version of this article (doi:10.1186/s12934-016-0424-8) contains supplementary material, which is available to authorized users.

Antiproliferative effects of methanolic extracts of Cryptocarya concinna Hance roots on oral cancer Ca9-22 and CAL 27 cell lines involving apoptosis, ROS induction, and mitochondrial depolarization

Cryptocarya-derived natural products were reported to have several biological effects such as the antiproliferation of some cancers. The possible antioral cancer effect of Cryptocarya-derived substances was little addressed as yet. In this study, we firstly used the methanolic extracts of C. concinna Hance roots (MECCrt) to evaluate its potential function in antioral cancer bioactivity. We found that MECCrt significantly reduced cell viability of two oral cancer Ca9-22 and CAL 27 cell lines in dose-responsive manners (P < 0.01). The percentages of sub-G1 phase and annexin V-positive of MECCrt-treated Ca9-22 and CAL 27 cell lines significantly accumulated (P < 0.01) in a dose-responsive manner as evidenced by flow cytometry. These apoptotic effects were associated with the findings that intracellular ROS generation was induced in MECCrt-treated Ca9-22 and CAL 27 cell lines in dose-responsive and time-dependent manners (P < 0.01). In a dose-responsive manner, MECCrt also significantly reduced the mitochondrial membrane potential in these two cell lines (P < 0.01–0.05). In conclusion, we demonstrated that MECCrt may have antiproliferative potential against oral cancer cells involving apoptosis, ROS generation, and mitochondria membrane depolarization.

Analysis of Antioxidant Properties and Major Components of the Extract of Paulownia tomentosa Steud Flowers

PaulowniatomentosaSteud flowers have been used for many therapeutic purposes in traditional pharmacopeia. The components of the extract ofPaulowniatomentosaSteud flowers were separated using ethanol elution. The antioxidant properties of different components (20% component, 40% component, 60% component, and 80% component) and synthetic antioxidants (BHA and BHT) were evaluated by scavenging DPPH, superoxide anions, and hydroxyl radical methods. All components showed strong antioxidant properties, especially the 60% component, which exhibited excellent antioxidant activity. These components may be developed for use as natural antioxidants. The main compounds in these components were identified using UPLC-TOF-MS/MS and UV spectra analysis. Two compounds, abscisic acid and t-abscisic acid, were found in the 20% component. Five compounds, t-abscisic acid, luteolin, apigenin, tricin, and 4′,5,7-trihydroxy-3′-methoxyflavone, were found in the 40% component. Three compounds, t-abscisic acid, apigenin and 4′,5,7-trihydroxy-3′-methoxyflavone, were found in the 60% component. Six compounds, luteolin, apigenin, 4′,5,7-trihydroxy-3′-methoxyflavone, paulownin, 3'-methyldiplacol, and diplacone, were found in the 80% component. The antioxidant activity of these components can be attributed to the main chemical composition of the components of the extract ofPaulowniatomentosaSteud flowers.

Nectandra amazonum-DerivedFlavonoids as COX-1 Inhibitors:In Vitroand Docking Studies

The ability of eleven known flavonoids isolated from Nectandra amazonum (Lauraceae) was tested for in vitro PGHS (COX) inhibition. All test compounds exhibited a dose dependent activity at different levels, exhibiting selectivity towards COX-1 inhibition. Autodock Vina was used to dock the compound structures within the active site of the PGHS-1 (PDB: 3N8V). In vitro results showed that chalcone and dihydrochalcone-related compounds exhibited reasonable inhibitory properties (IC50: 1.56-36.5 μM), with good correlation with docking results. Arg120 (or Tyr355) and Ser530 were found to be the key residues to dock the most active flavonoids, indicating such interaction might interfere with the formation of prostaglandin H2in the active site of COX-1.

Constituents of an extract of Cryptocarya rubra housed in a repository with cytotoxic and glucose transport inhibitory effects

A new alkylated chalcone (1), a new 1,16-hexadecanediol diester (2), and eight known compounds were isolated from a dichloromethane-soluble repository extract of the leaves and twigs of Cryptocarya rubra collected in Hawaii. The structures of the new compounds were determined by interpretation of their spectroscopic data, and the absolute configurations of the two known cryptocaryanone-type flavonoid dimers, (+)-bicaryanone A (3) and (+)-chalcocaryanone C (4), were ascertained by analysis of their electronic circular dichroism and NOESY NMR spectra. All compounds isolated were evaluated against HT-29 human colon cancer cells, and, of these, (+)-cryptocaryone (5) was found to be potently cytotoxic toward this cancer cell line, with an IC50 value of 0.32 μM. This compound also exhibited glucose transport inhibitory activity when tested in a glucose uptake assay.

A new approach to asymmetric synthesis of infectocaryone

A new approach to the asymmetric synthesis of infectocaryone featuring a regioselective and stereoselective Diels–Alder reaction of an isomeric dienophile mixture is developed.

Pinocembrin: a novel natural compound with versatile pharmacological and biological activities

Pinocembrin (5,7-dihydroxyflavanone) is one of the primary flavonoids isolated from the variety of plants, mainly from Pinus heartwood, Eucalyptus, Populus, Euphorbia, and Sparattosperma leucanthum, in the diverse flora and purified by various chromatographic techniques. Pinocembrin is a major flavonoid molecule incorporated as multifunctional in the pharmaceutical industry. Its vast range of pharmacological activities has been well researched including antimicrobial, anti-inflammatory, antioxidant, and anticancer activities. In addition, pinocembrin can be used as neuroprotective against cerebral ischemic injury with a wide therapeutic time window, which may be attributed to its antiexcitotoxic effects. Pinocembrin exhibits pharmacological effects on almost all systems, and our aim is to review the pharmacological and therapeutic applications of pinocembrin with specific emphasis on mechanisms of actions. The design of new drugs based on the pharmacological effects of pinocembrin could be beneficial. This review suggests that pinocembrin is a potentially promising pharmacological candidate, but additional studies and clinical trials are required to determine its specific intracellular sites of action and derivative targets in order to fully understand the mechanism of its anti-inflammatory, anticancer, and apoptotic effects to further validate its medical applications.

Cytotoxic constitutents from Cryptocarya maclurei

A phytochemical study of Cryptocarya maclurei led to isolation of five flavanones, cryptogiones G-H, and a polyketide, cryptomaclurone. The structures of the isolates were elucidated by analysis of the 1D and 2D NMR spectroscopic data, and their absolute configurations were determined by CD methods. A putative biosynthetic pathway to them is proposed. Cytotoxicity of these compounds evaluated against KB, SGC-7901 and SW 1116 cancer cell lines, with only cryptomaclurone exhibiting moderate cytotoxicity (IC50 28.2, 28.4 and 16.4μM, respectively).

Naturally derived anti-inflammatory compounds from Chinese medicinal plants

ETHNOPHARMACOLOGICAL RELEVANCE

Though inflammatory response is beneficial to body damage repair, if it is out of control, it can produce adverse effects on the body. Although purely western anti-inflammatory drugs, orthodox medicines, can control inflammation occurrence and development, it is not enough. The clinical efficacy of anti-inflammation therapies is unsatisfactory, thus the search for new anti-inflammation continues. Chinese Material Medica (CMM) remains a promising source of new therapeutic agents. CMM and herbal formulae from Traditional Chinese Medicine (TCM), unorthodox medicines, play an improtant anti-inflammatory role in multi-targets, multi-levels, and multi-ways in treating inflammation diseases in a long history in China, based on their multi-active ingredient characteristics. Due to these reasons, recently, CMM has been commercialized as an anti-inflammation agent which has become increasingly popular in the world health drug markets. Major research contributions in ethnopharmacology have generated vast amount of data associated with CMM in anti-inflammtion aspect. Therefore, a systematic introduction of CMM anti-inflammatory research progress is of great importance and necessity.

AIM OF THE STUDY

This paper strives to describe the progress of CMM in the treatment of inflammatory diseases from different aspects, and provide the essential theoretical support and scientific evidence for the further development and utilization of CMM resources as a potential anti-inflammation drug through a variety of databases.

MATERIAL AND METHODS

Literature survey was performed via electronic search (SciFinder®, Pubmed®, Google Scholar and Web of Science) on papers and patents and by systematic research in ethnopharmacological literature at various university libraries.

RESULTS

This review mainly introduced the current research on the anti-inflammatory active ingredient, anti-inflammatory effects of CMM, their mechanism, anti-inflammatory drug development of CMM, and toxicological information.

CONCLUSION

CMM is used clinically to treat inflammation symptoms in TCM, and its effect is mediated by multiple targets through multiple active ingredients. Although scholars around the world have made studies on the anti-inflammatory studies of CMM from different pathways and aspects and have made substantial progress, further studies are warranted to delineate the inflammation actions in more cogency models, establish the toxicological profiles and quality standards, assess the potentials of CMM in clinical applications, and make more convenient preparations easy to administrate for patients. Development of the clinically anti-inflammatory drugs are also warranted.