Innovative orthogonal two-dimensional reversed-phase liquid chromatography × supercritical fluid chromatography with a phenyl/tetrazole stationary phase for the preparative isolation of diarylheptanoids.

In this investigation, we successfully isolated and purified natural diarylheptanoids using an orthogonal offline two-dimensional RPLC × SFC approach, employing only the phenyl/tetrazole stationary phase. First, a styrene-divinylbenzene matrix medium pretreatment liquid chromatography system effectively processed chlorophyll-containing plant extract solution with a recovery rate of 33.8 %, obviating the need for concentration steps. Subsequently, an offline two-dimensional RPLC × SFC employing only the phenyl/tetrazole stationary phase achieved a remarkable 96.38 % orthogonality and was established and utilized in the preparative separation and purification of natural products. Finally, the constructed single stationary phase highly orthogonal RPLC × SFC system was successfully applied in the preparative separation and purification of natural diarylheptanoids from the Saxifraga tangutica target fraction and yielded four diarylheptanoids with purities exceeding 95 %.

Ru(II)-Arene Complexes of Curcumin and Bisdesmethoxycurcumin Metabolites.

Curcuminoids and their complexes continue to attract attention in medicinal chemistry, but little attention has been given to their metabolic derivatives. Here, the first examples of (arene)Ru(II) complexes with curcuminoid metabolites, tetrahydrocurcumin (THcurcH), and tetrahydrobisdesmethoxycurcumin (THbdcurcH) were prepared and characterized. The neutral complexes [Ru(arene)(THcurc)Cl] and [Ru(arene)(THbdcurc)Cl] (arene = cymene, benzene, or hexamethylbenzene) were characterized by NMR spectroscopy and ESI mass spectrometry, and the crystal structures of the three complexes were determined by X-ray diffraction analysis. Compared to curcuminoids, these metabolites lose their conjugated double bond system responsible for their planarity, showing unique closed conformation structures. Both closed and open conformations have been analyzed and rationalized by using density functional theory (DFT). The cytotoxicity of the complexes was evaluated in vitro against human ovarian carcinoma cells (A2780 and A2780cisR), human breast adenocarcinoma cells (MCF-7 and MCF-7CR), as well as against non-tumorigenic human embryonic kidney cells (HEK293) and human breast (MCF-10A) cells and compared to the free ligands, cisplatin, and RAPTA-C. There is a correlation between cellular uptake and the cytotoxicity of the compounds, suggesting that cellular uptake and binding to nuclear DNA may be the major pathway for cytotoxicity. However, the levels of complex binding to DNA do not strictly correlate with the cytotoxic potency, indicating that other mechanisms are also involved. In addition, treatment of MCF-7 cells with [Ru(cym)(THcurc)Cl] showed a significant decrease in p62 protein levels, which is generally assumed as a noncisplatin-like mechanism of action involving autophagy. Hence, a cisplatin- and a noncisplatin-like concerted mechanism of action, involving both apoptosis and autophagy, is possible.

Dimeric diarylheptanoids with anti-inflammatory activity from Zingiber officinale.

Two previously undescribed chain diarylheptanoid derivatives (2-3), five previously undescribed dimeric diarylheptanoids (4-8), together with one known cyclic diarylheptanoid (1) were isolated from Zingiber officinale. Their structures were elucidated by extensive spectroscopic analyses (HR-ESI-MS, IR, UV, 1D and 2D NMR) and ECD calculations. Biological evaluation of compounds 1-8 revealed that compounds 2, 3 and 4 could inhibit nitrite oxide and IL-6 production in lipopolysaccharide induced RAW264.7 cells in a dose-dependent manner.

Cloning and characterization of NADPH-dependent double-bond reductases from Alnus sieboldiana that recognize linear diarylheptanoids as substrates.

Diarylheptanoids are secondary metabolites of plants that comprise a C6-C7-C6 scaffold. They can be broadly classified into linear-type and cyclic-type diarylheptanoids based on their chemical structures. Actinorhizal trees, such as Casuarina, Alnus, and Myrica, which form nodule symbiosis with actinomycetes Frankia, produce cyclic diarylheptanoids (CDHs); in Alnus sieboldiana Matsum. in particular, we have reported that the addition of CDHs leads to an increase in the number of nodules. However, the information available on the biosynthesis of CDHs is scarce. A greater number of plants CDHs (including those isolated from actinorhizal trees) with a saturated heptane chain have been isolated compared with linear, non-cyclic diarylheptanoids. To identify the genes involved in the synthesis of these compounds, genes with significant sequence similarity to existing plant double-bond reductases were screened in A. sieboldiana. This report describes the isolation and characterization of two A. sieboldiana double-bond reductases (AsDBR1 and AsDBR2) that catalyze the NADPH-dependent reduction of bisdemethoxycurcumin and curcumin. The optimum pH for the two enzymes was 5.0. The apparent Km values for bisdemethoxycurcumin and NADPH were 4.24 and 3.53 µM in the case of AsDBR1, and 2.55 and 2.13 µM for AsDBR2. The kcat value was 9.4-fold higher for AsDBR1 vs. AsDBR2 when using the bisdemethoxycurcumin substrate. Interestingly, the two AsDBRs failed to reduce the phenylpropanoid monomer.

Diarylheptanoids with hypoglycemic potency from the rhizomes of Kaempferia galanga.

Five new diarylheptanoids, kaemgalangins A-E (1-5), and seven known ones were isolated from the rhizomes of Kaempferia galanga. The structures of new compounds were identified by spectroscopic analyses involving 1D and 2D NMR, HRESIMS, IR, UV, [α]D, ECD calculations, and chemical methods. All compounds were tested for their hypoglycemic effects against α-glucosidase, Gpa and PTP1B enzymes, and stimulative effects on GLP-1 secretion. Kaemgalangins A (1) and E (5) showed significant inhibition on α-glucosidase with IC50 values of 45.3 and 116.0 µM; renealtin B (8) showed inhibition on GPa with an IC50 value of 68.1 µM; whereas all compounds were inactive to PTP1B. Docking study manifested that 1 well located in the catalytic pocket of α-glucosidase and OH-4″ played important roles in maintaining activity. Moreover, all compounds showed obviously stimulative effects on GLP-1 with promoting rates of 826.9%-1738.3% in NCI-H716 cells. This study suggests that the diarylheptanoids in K. galanga have antidiabetic potency by inhibiting α-glucosidase and Gpa enzymes, and promoting GLP-1 secretion.

Pharmacological safety of dimethoxy curcumin-human serum albumin conjugate for potential therapeutic purpose.

Medicinal properties of curcumin are widely published. Previously, researchers used curcuminoid mixture comprising three chemical forms, out of which, the highest quantity is the most active molecule-dimethoxy curcumin (DMC). Reduced bioavailability, poor aqueous solubility, and quick hydrolytic degradation of DMC have projected challenges limiting its therapeutic value. However, selective conjugation of DMC with human serum albumin (HSA) enhances drug stability and solubility by several folds. Studies using animal models demonstrated potential anti-cancer/anti-inflammatory effects of DMCHSA; both studies showed results of local administration in peritoneal cavity and rabbit knee joint. DMC has prospects as intravenous therapeutic agent because carrier is HSA. However, before in vivo testing, important preclinical data required are toxicological safety and bioavailability of soluble forms of DMC. This study evaluated absorption, distribution, metabolism, and excretion of DMCHSA. Imaging technology and molecular analysis proved bio-distribution. The study also assessed the pharmacological safety of DMCHSA in mice in terms of its acute and sub-acute toxicity, complying with regulatory toxicology. Overall, the study demonstrated the safety pharmacology of DMCHSA upon intravenous infusion. This is a novel study establishing the safety of highly soluble and stable formulation of DMCHSA, qualifying it for intravenous administration and further efficacy evaluation in suitable disease models.

Discovery of Cyclic Diarylheptanoids as Inhibitors against Influenza A Virus from the Roots of Casuarina equisetifolia.

Four new cyclic diarylheptanoids, casuarinols A-C (1-3) and casuarinolide A (4), together with six known ones (5-10), were isolated from the roots of Casuarina equisetifolia. Structures were elucidated by extensive spectroscopic analysis, theoretical conformational, and electronic circular dichroism analyses. Casuarinol C (3) is a novel cyclic diarylheptanoid-aldehyde adduct. Casuarinolide A (4) represents the first structure of a seco-cyclic diarylheptanoid. Compounds 1-9 were evaluated for their anti-influenza A virus (IAV) activity against A/WSN/33 (H1N1). (-)-(M)-11-Oxo-3,12R,17-trihydroxy-9-ene-[7,0]-metacyclophane (5) displayed significant anti-IAV activity with an IC50 value of 8.64 ± 2.49 µM and a CC50 higher than 100 µM.

Extraction of curcuminoids and ar-turmerone from turmeric (Curcuma longa L.) using hydrophobic deep eutectic solvents (HDESs) and application as HDES-based microemulsions.

The extraction of curcuminoids and aromatic (ar)-turmerone from Curcuma longa L. using organic solvents produces chemical waste, and is therefore incompatible with food applications. To address this issue, this study presents the design of hydrophobic deep eutectic solvents (HDESs) and HDES-based microemulsions. Using the response surface methodology (RSM), the optimal extraction conditions were identified as follows: HDES = OA:menthol (1:3.6 M ratio), solid-to-liquid ratio = 10:1 (mg/mL), and extraction duration = 90 min (prediction accuracy ≥ 85 %). Under these conditions, the HDES extraction yields of bisdemethoxycurcumin, demethoxycurcumin, curcumin, and ar-turmerone were 2.49 ± 0.25, 5.61 ± 0.45, 9.40 ± 0.86, and 3.83 ± 0.19 % (w/w, dry basis), respectively, while those obtained using the HDES-based microemulsion were 2.10 ± 0.18, 6.31 ± 0.48, 12.6 ± 1.20, and 2.58 ± 0.19 % (w/w, dry basis), respectively. The HDES and its microemulsions are more effective and environmentally friendly than conventional organic solvents for the extraction of curcuminoids and ar-turmerone, and these solvents are also compatible with food and pharmaceutical formulations.

Computational approach to decode the mechanism of curcuminoids against neuropathic pain.

BACKGROUND: Curcumin (CUR), demethoxycurcumin (DMC) and bisdemethoxycurcumin (BDMC) are the main components of turmeric that commonly used to treat neuropathic pain (NP). However, the mechanism of the therapy is not sufficiently clarified. Herein, network pharmacology, molecular docking and molecular dynamics (MD) approaches were used to investigate the mechanism of curcuminoids for NP treatment. METHODS: Active targets of curcuminoids were obtained from the Swiss Target database, and NP-related targets were retrieved from GeneCards, OMIM, Drugbank and TTD databases. A protein-protein interaction (PPI) network was built to screen the core targets. Furthermore, DAVID was used for GO and KEGG pathway enrichment analyses. Interactions between potential targets and curcuminoids were assessed by molecular docking and the MD simulations were run for 100ns to validate the docking results on the top six complexes. RESULTS: CUR, DMC, and BDMC had 100, 99 and 100 targets respectively. After overlapping with NP there were 33, 33 and 31 targets respectively. PPI network analysis of TOP 10 core targets, TNF, GSK3ß were common targets of curcuminoids. Molecular docking and MD results indicated that curcuminoids bind strongly with the core targets. The GO and KEGG showed that curcuminoids regulated nitrogen metabolism, the serotonergic synapse and ErbB signaling pathway to alleviate NP. Furthermore, specific targets in these three compounds were also analysed at the same time. CONCLUSIONS: This study systematically explored and compared the anti-NP mechanism of curcuminoids, providing a novel perspective for their utilization.

Screening method for chromatographic analysis of diarylheptanoids in alder bark extracts.

An experimentally proven novel analytical approach for chromatographic analysis of diarylheptanoids in grey alder (Alnus incana) and black alder (Alnus glutinosa) bark matrices was established. A method for qualitative and quantitative determination of oregonin (dominant diarylheptanoid) and semiquantitative analysis of related diarylheptanoids from alder bark using a photodiode array (PDA) detector coupled to a high-resolution mass spectrometer (QTOF-MS) was developed. A comparison of different liquid chromatography detectors (UV, MS and ELS) showed that only a combination of them is applicable for comprehensive analysis of multicomponent extracts. A total of sixteen different diarylheptanoids were simultaneously identified and semi-quantified in alder bark extracts. This is the first report of the method for individual and total diarylheptanoid determination in alder bark extracts, discussed in detail. The liquid chromatography complex is suggested as a tool for the reliable identification and quality control of the diarylheptanoids containing extracts isolated from the Alnus species and their dominant component - oregonin. The semiquantitative methodology established, and the dominant compound quantification provided means for assessing comparative sample complexities.

New diarylheptanoid dimers as GLP-1 secretagogues and multiple-enzyme inhibitors from Alpinia katsumadai.

Ten new diarylheptanoid dimers, katsumadainols C1 - C10 (1-10), were isolated from the seeds of Alpinia katsumada and elucidated by extensive spectroscopic methods, ECD calculations, and single-crystal X-ray diffraction. Their antidiabetic effects were evaluated by the stimulation of GLP-1 secretion in STC-1 cells and inhibition against four diabetes-related enzymes, GPa, α-glucosidase, PTP1B, and DPP4. Compounds 1-5 and 7-10 significantly stimulated GLP-1 secretion by 267.5-433.1% (25.0 µM) and 117.8-348.2% (12.5 µM). Compounds 1-4 exhibited significant inhibition on GPa with IC50 values of 18.0-31.3 µM; compounds 1-5 showed obvious inhibition on α-glucosidase with IC50 values of 6.9-18.2 µM; compounds 1-5 and 10 possessed PTP1B inhibitory activity with IC50 values ranging from 35.5 to 80.1 µM. This investigation first disclosed compounds 1-4 as intriguing GLP-1 secretagogues and GPa, α-glucosidase, and PTP1B inhibitors, which provided valuable clues for searching multiple-target antidiabetic candidates from Zingiberaceae plants.

Study on the Synthesis of Methylated Reference and Their Application in the Quantity of Curcuminoids Using Single Reference Liquid Chromatography Based on Relative Molar Sensitivity.

We report on the recommendation of the simple and versatility of methylated reference (MR) to improve applications in the single reference (SR)-LC based on relative molar sensitivity (RMS). Three curcuminoids (Curs) such as curcumin, demethoxycurcumin and bisdemethoxycurcumin in turmeric products were determined using authentic standards and methylated curcumin. In addition, high-speed countercurrent chromatography (HSCCC) purification is necessary to separate Curs for indicating the RMS. For HSCCC separation, a biphasic solvent system was used to obtain these fractions, which were then subjected to 1H quantitative NMR to determine their contents in each test solution. Using these solutions, the RMS of Curs are calculated from slopes ratios of calibration curves (three ranges from 0-100 µmol/L, r2 > 0.998). The averaged RMS of Curs were 8.92 (relative standard deviation (RSD), 1.17%), 8.97 (2.18%), and 9.61 (0.77%), respectively. Cur concentrations in turmeric products can be determined using RMS, peak area, and MR content added in these samples. This proposed method, which is based on chemical methylation and the SR-LC assay has been successfully applied for the simple and reliable estimation of Curs in turmeric products.

Influence of different preparation techniques on the composition and antioxidant action of curcumin and curcuminoids / Influencia de diferentes técnicas de preparación en la composición y acción antioxidante de la curcumina y los curcuminoides

Epidemiological evidence indicates that plant antioxidants activity can treat or help to prevent the development of various diseases. One species with great potential as an antioxidant is Curcuma longa. However, different extraction techniquescan influence isolated chemical compounds. This study investigated chemical composition and antioxidant activity of two rhizome extracts of C. longa: hydroethanolic, obtained by exhaustion (HECLex); and dried by a spray dryer (HECLsd). The phytochemical composition was evaluated by GC/MS. Antioxidant activity was evaluated using DPPH and FRAP assays. Total phenolic compounds and soil analyses were performed. The main components of HECLex were ar-turmerone, γ-curcumene, α-turmerone, and ß-sesquiphellandrene. The main components of HECLsd were 9,12,15-octadecatrienoic acid, 2, 3-bis([trimethylsilyl]oxy) propyl ester, verrucarol, and 1-monolinoleoylglycerol trimethylsilyl ether. HECLsd had significantly higher levels of phenolic compounds and higher antioxidant capacity compared with HECLex. In conclusion, processes of the preparation of C. longarhizomes alter the chemical components and consequently their biological activity.

La evidencia epidemiológica indica que la actividad de los antioxidantes de las plantas pueden tratar o ayudar a prevenir el desarrollo de diversas enfermedades. Una especie con gran potencial como antioxidante es Curcuma longa. Sin embargo, diferentes técnicas de extracción pueden influir en los compuestos químicos aislados. Este estudio investigó la composición química y la actividad antioxidante de dos extractos de rizoma de C. longa: hidroetanólico, obtenido por agotamiento (HECLex); y se seca con un secador por pulverización (HECLsd). La composición fitoquímica se evaluó mediante GC/MS. La actividad antioxidante se evaluó mediante ensayos DPPH y FRAP. Se realizaron análisis de suelos y compuestos fenólicos totales. Los componentes principales de HECLex fueron ar-turmerona, γ-curcumene, α-turmerone y ß-sesquiphellandrene. Los componentes principales de HECLsd fueron ácido 9,12,15-octadecatrienoico, éster 2,3-bis ([trimetilsilil] oxi) propílico, verrucarol y éter 1-monolinoleoilglicerol trimetilsilil. HECLsd tenía niveles significativamente más altos de compuestos fenólicos y mayor capacidad antioxidante en comparación con HECLex. En conclusión, los procesos de preparación de los rizomas de C. longa alteran los componentes químicos y consecuentemente su actividad biológica.

Two undescribed diarylheptanoids from green husk of Carya illinoinensis as acetylcholinesterase inhibitors.

Two undescribed diarylheptanoids, 3-(R)-acetyl-1-(3',4'-dihydroxyphenyl)-7-(4''-hydroxy-3'' -methoxyphenyl)-heptane (1) and 11-Hydroxy-1,17-epoxy-7-(2-hydroxylphenyl)-13-(16-methoxyphenyl)-heptane (2) together with known compounds, namely, 11-Oxo-1,17-epoxy-7-(2-hydroxylphenyl)-13-(16-methoxyphenyl)-heptane (3) 3,4,5-Trihydroxytetralone (4) 4,8- Dihydroxytetralone (5), 4,5-Dihydroxytetralone (6), 5,8-Dihydroxy-3-methoxytetralone (7) were isolated from ethyl acetate extract of the green husk of Carya illinoinensis. The structures of compounds were established on the basis of IR, 1H NMR, 13C NMR, DEPT, HSQC, HMBC, COSY spectroscopic and ESI-MS analysis. The isolated compounds were evaluated for AChE (acetylcholinesterase inhibition) and observed that compound 5 was potent inhibitor with IC50 of 101.48 ± 4.00 µg/mL.

New cyclic diarylheptanoids from the false heartwood of Betula pubescens Ehrh.

Two undescribed (1-2) and five known cyclic diarylheptanoids (3-7) were isolated from the false heartwood of white birch (Betula pubescens Ehrh.). All structures were elucidated through extensive 1D and 2D NMR experiments and HR-ESI-MS data, along with comparison of their spectroscopic data with those reported in the literature. The two new cyclic diarylheptanoids are betuladiol (1) and betulondiol (2). Extracts from false heartwood were evaluated for their antimicrobial activity against Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, Staphylococcus aureus and Cutibacterium acnes together with their antifungal activity against Candida albicans and Candida glabrata.

Diarylheptanoid glycosides from Zingiber officinale peel and their anti-apoptotic activity.

Four new diarylheptanoid glycosides (1-4), (1S,3R,5S)-2-(4-hydroxy-3- methoxyphenyl)-6-[2-(4-hydroxyphenyl)ethyl]-tetrahydropyran-4-ol-4'-O-ß-D-glucopyranoside (1), (1S,3R,5S)-2-(4,5-dihydroxy-3-methoxyphenyl)-6-[2-(4-hydroxyphenyl) ethyl]-tetrahydropyran-4-ol-4'-O-ß-D-glucopyranoside (2), (1S,3R,5S)-2-(4-hydroxy- 3,5-dimethoxyphenyl)-6-[2-(4-hydroxy-3-methoxyphenyl)ethyl]-tetrahydropyran-4-ol-4'-O-ß-D-glucopyranoside (3), and (1R,3R,5R)-2-(4-hydroxy-3,5-dimethoxyphenyl)- 6-[2-(4-hydroxy-3-methoxyphenyl)ethyl]-tetrahydropyran-4-ol-3-O-ß-D-glucopyranoside (4) were isolated from the 50% ethanol extract of Zingiber officinale peel. The structures of the isolated compounds were determined by HR-ESI-MS and extensive spectroscopic techniques (UV, IR, 1D-NMR, and 2D-NMR). Compounds 1-4 significantly increased the survival rate of human normal lung bronchial epithelial cells (BEAS-2B) induced by lipopolysaccharide (LPS) at the concentration of 10 µM.

Design, Synthesis and Evaluation of Novel Derivatives of Curcuminoids with Cytotoxicity.

Curcumin and curcuminoids have been discussed frequently due to their promising functional groups (such as scaffolds of α,ß-unsaturated ß-diketone, α,ß-unsaturated ketone and ß'-hydroxy-α,ß-unsaturated ketone connected with aromatic rings on both sides) that play an important role in various bioactivities, including antioxidant, anti-inflammatory, anti-proliferation and anticancer activity. A series of novel curcuminoid derivatives (a total of 55 new compounds) and three reference compounds were synthesized with good yields using three-step organic synthesis. The anti-proliferative activities of curcumin derivatives were examined for six human cancer cell lines: HeLaS3, KBvin, MCF-7, HepG2, NCI-H460 and NCI-H460/MX20. Compared to the IC50 values of all the synthesized derivatives, most α,ß-unsaturated ketones displayed potent anti-proliferative effects against all six human cancer cell lines, whereas ß'-hydroxy-α,ß-unsaturated ketones and α,ß-unsaturated ß-diketones presented moderate anti-proliferative effects. Two potent curcuminoid derivatives were found among all the novel derivatives and reference compounds: (E)-5-hydroxy-7-phenyl-1-(3,4,5-trimethoxyphenyl)hept-1-en-3-one (compound 3) and (1E,4E)-1,7-bis(3,4,5-trimethoxyphenyl)hepta-1,4-dien-3-one (compound MD12a). These were selected for further analysis after the evaluation of their anti-proliferative effects against all human cancer cell lines. The results of apoptosis assays revealed that the number of dead cells was increased in early apoptosis and late apoptosis, while cell proliferation was also decreased after applying various concentrations of (E)-5-hydroxy-7-phenyl-1-(3,4,5-trimethoxyphenyl)hept-1-en-3-one (compound 3) and (1E,4E)-1,7-bis(3,4,5-trimethoxyphenyl)hepta-1,4-dien-3-one (compound MD12a) to MCF-7 and HpeG2 cancer cells. Analysis of the gene expression arrays showed that three genes (GADD45B, SESN2 and BBC3) were correlated with the p53 pathway. From the quantitative PCR analysis, it was seen that (1E,4E)-1,7-bis(3,4,5-trimethoxyphenyl)hepta-1,4-dien-3-one (compound MD12a) effectively induced the up-regulated expression of GADD45B, leading to the suppression of MCF-7 cancer cell formation and cell death. Molecular docking analysis was used to predict and sketch the interactions of the GADD45B-α,ß-unsaturated ketone complex for help in drug design.

Stable Catechol Keto Tautomers in Cytotoxic Heterodimeric Cyclic Diarylheptanoids from the Seagrass Zostera marina.

Two diarylheptanoid heterodimers, zosterabisphenones A (1) and B (2), were isolated from the seagrass Zostera marina. They feature unprecedented catechol keto tautomers, stable because of steric constraints. Their structure elucidation was based on extensive low-temperature NMR studies and ECD and MS data, with the essential aid of DFT prediction of NMR and ECD spectra. Zosterabisphenone B (2) was selectively cytotoxic against the adenocarcinoma colon cancer cell line HCT116 with IC50 3.6 ± 1.1 µM at 48 h.

The Demethoxy Derivatives of Curcumin Exhibit Greater Differentiation Suppression in 3T3-L1 Adipocytes Than Curcumin: A Mechanistic Study of Adipogenesis and Molecular Docking.

Curcumin is a known anti-adipogenic agent for alleviating obesity and related disorders. Comprehensive comparisons of the anti-adipogenic activity of curcumin with other curcuminoids is minimal. This study compared adipogenesis inhibition with curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC), and their underlying mechanisms. We differentiated 3T3-L1 cells in the presence of curcuminoids, to determine lipid accumulation and triglyceride (TG) production. The expression of adipogenic transcription factors and lipogenic proteins was analyzed by Western blot. A significant reduction in Oil red O (ORO) staining was observed in the cells treated with curcuminoids at 20 µM. Inhibition was increased in the order of curcumin < DMC < BDMC. A similar trend was observed in the detection of intracellular TG. Curcuminoids suppressed differentiation by downregulating the expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), leading to the downregulation of the lipogenic enzymes acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS). AMP-activated protein kinase α (AMPKα) phosphorylation was also activated by BDMC. Curcuminoids reduced the release of proinflammatory cytokines and leptin in 3T3-L1 cells in a dose-dependent manner, with BDMC showing the greatest potency. BDMC at 20 µM significantly decreased leptin by 72% compared with differentiated controls. Molecular docking computation indicated that curcuminoids, despite having structural similarity, had different interaction positions to PPARγ, C/EBPα, and ACC. The docking profiles suggested a possible interaction of curcuminoids with C/EBPα and ACC, to directly inhibit their expression.

Alnus sibirica Compounds Exhibiting Anti-Proliferative, Apoptosis-Inducing, and GSTP1 Demethylating Effects on Prostate Cancer Cells.

Alnus sibirica (AS) is distributed in Korea, Japan, China, and Russia and has reported anti-oxidant, anti-inflammatory, and reducing activities on atopic dermatitis-like skin lesions, along with other beneficial health properties. In the present study, we tried to prove the cancer-preventive activity against prostate cancer. The extracted and isolated compounds, oregonin (1), hirsutenone (2), and hirsutanonol (3), which were isolated from AS, were tested for anti-proliferative activity. To do this, we used the MTT assay; NF-κB inhibitory activity, using Western blotting; apoptosis-inducing activity using flow cytometry; DNA methylation activity, using methylation-specific polymerase chain reaction in androgen-dependent (LNCaP) and androgen-independent (PC-3) prostate cancer cell lines. The compounds (1-3) showed potent anti-proliferative activity against both prostate cancer cell lines. Hirsutenone (2) exhibited the strongest NF-κB inhibitory and apoptosis-inducing activities compared with oregonin (1) and hirsutanonol (3). DNA methylation activity, which was assessed for hirsutenone (2), revealed a concentration-dependent enhancement of the unmethylated DNA content and a reduction in the methylated DNA content in both PC-3 and LNCaP cells. Overall, these findings suggest that hirsutenone (2), when isolated from AS, may be a potential agent for preventing the development or progression of prostate cancer.