Optimization of Ultrasound-Assisted Extraction of Yields and Total Methoxyflavone Contents from Kaempferia parviflora Rhizomes.

The major bioactive components of Kaempferia parviflora (KP) rhizomes, 3,5,7,3',4'-pentamethoxyflavone (PMF), 5,7-dimethoxyflavone (DMF), and 5,7,4'-trimethoxyflavone (TMF), were chosen as the quantitative and qualitative markers for this plant material. In order to extract bioactive components (total methoxyflavones) from KP rhizomes, ultrasound-assisted extraction (UAE) was proposed as part of this study. Plackett-Burman design (PBD) and Box-Behnken design (BBD) were utilized to optimize the effects of UAE on extraction yields and total methoxyflavone contents in KP rhizomes. First, PBD was utilized to determine the effect of five independent variables on total yields and total methoxyflavone contents. The results indicated that the concentration of the extracting solvent (ethanol), the extraction time, and the ratio of solvent to solid were significant independent terms. Subsequently, BBD with three-level factorial experiments was used to optimize the crucial variables. It was discovered that the concentration of ethanol was the most influential variable on yields and total methoxyflavone contents. Optimum conditions for extraction yield were ethanol concentration (54.24% v/v), extraction time (25.25 min), and solvent-to-solid ratio (49.63 mL/g), while optimum conditions for total methoxyflavone content were ethanol concentration (95.00% v/v), extraction time (15.99 min), and solvent-to-solid ratio (50.00 mL/g). The relationship between the experimental and theoretical values was perfect, which proved that the regression models used were correct and that PBD and BBD were used to optimize the conditions in the UAE to obtain the highest yield and total methoxyflavone content in the KP rhizomes.

Bio-Efficacy of Chrysoeriol7, a Natural Chemical and Repellent, against Brown Planthopper in Rice.

Brown planthopper (BPH, Nilaparvata lugens Stal.) is the most damaging rice pest affecting stable rice yields worldwide. Currently, methods for controlling BPH include breeding a BPH-resistant cultivar and using synthetic pesticides. Nevertheless, the continuous cultivation of resistant cultivars allows for the emergence of various resistant races, and the use of synthetic pesticides can induce environmental pollution as well as the emergence of unpredictable new pest species. As plants cannot migrate to other locations on their own to combat various stresses, the production of secondary metabolites allows plants to protect themselves from stress and tolerate their reproduction. Pesticides using natural products are currently being developed to prevent environmental pollution and ecosystem disturbance caused by synthetic pesticides. In this study, after BPH infection in rice, chrysoeriol7 (C7), a secondary metabolite that induces resistance against BPH, was assessed. After C7 treatment and BPH infection, relative expression levels of the flavonoid-related genes were elevated, suggesting that in plants subjected to BPH, compounds related to flavonoids, among the secondary metabolites, play an important role in inducing resistance. The plant-derived natural compound chrysoeriol7 can potentially thus be used to develop environmentally friendly pesticides. The suggested control of BPH can be effectively used to alleviate concerns regarding environmental pollution and to construct a relatively safe rice breeding environment.

Total flavone of Abelmoschus Manihot improves colitis by promoting the growth of Akkermansia in mice.

The total flavone of Abelmoschus manihot (TFA), a compound extracted from the flowers of Abelmoschus manihot (L.) Medic, has been widely used for the treatment of Crohn's disease, chronic glomerulonephritis and other diseases. The aim of this study was to investigate the effect of TFA on the gut microbiota and intestinal barrier in dextran sulfate sodium (DSS)-induced experimental colitis. C57BL/6J mice were treated with 2.5% DSS in drinking water to induce colitis. Mice were orally administered TFA (62.5 mg/kg, 125 mg/kg) or prednisone acetate (PAT, 2.5 mg/kg) once daily for 7 days. Biological samples were collected for analysis of inflammatory cytokines, gut microbiota and intestinal barrier integrity. TFA-H (125 mg/kg) markedly attenuated DSS-induced colon shortening and histological injury in experimental colitis. The therapeutic effect was similar to that of PAT administration. TFA-H notably modulated the dysbiosis of gut microbiota induced by DSS and greatly enriched Akkermansia muciniphila (A. muciniphila). Moreover, TFA-H remarkably ameliorated the colonic inflammatory response and intestinal epithelial barrier dysfunction. Interestingly, TFA directly promotes the growth of A. muciniphila in vitro. Taken together, the results revealed for the first time that TFA, as a prebiotic of A. muciniphila, improved DSS-induced experimental colitis, at least partly by modulating the gut microflora profile to maintain colonic integrity and inhibit the inflammatory response.

New Flavone C-Glycosides from Scleranthus perennis and Their Anti-Collagenase Activity.

Three new flavone glycosides, one known flavone glycoside, and the phenolic derivative apiopaenonside were isolated and identified from the ethyl acetate fraction of the aerial parts of Scleranthus perennis. The planar structures were elucidated through extensive analysis of UV-Vis, IR, and 1H NMR and 13C NMR spectral data, including the 2D techniques COSY, HSQC, and HMBC, as well as ESI mass spectrometry. The isolated compounds were established as 5,7,3'-trihydroxy-4'-acetoxyflavone-8-C-ß-d-xylopyranoside-2''-O-glucoside (1), 5,7,3'-trihydroxy-4'-methoxyflavone-8-C-ß-d-xylopyranoside-2''-O-glucoside (2), 5,7-dihydroxy-3'-methoxy-4'-acetoxyflavone-8-C-ß-d-xylopyranoside-2''-O-glucoside (3), 5,7-dihydroxy-3'-methoxy-4'-acetoxyflavone-8-C-ß-d-xylopyranoside-2''-O-(4'''-acetoxy)-glucoside (4), and apiopaenonside (5). Moreover, all isolated compounds were evaluated for anti-collagenase activity. All compounds exhibited moderate inhibitory activity with IC50 values ranging from 36.06 to 70.24 µM.

Cudraflavone C from Artocarpus hirsutus as a Promising Inhibitor of Pathogenic, Multidrug-Resistant S. aureus, Persisters, and Biofilms: A New Insight into a Rational Explanation of Traditional Wisdom.

Artocarpus hirsutus Lam., or wild jack, a perennial tree of the Western Ghats of peninsular India, serves as a rich source of flavonoids. The indigenous knowledge of this multipurpose flora chronicles the efficient property of its bark as a natural treatment for various skin infections. Herein, we describe a rational explanation of this traditional knowledge via a broader evaluation of inhibitory activity of one of its phytoconstituents, cudraflavone C (Cud C), a prenyl flavone isolated from stem bark against diverse multidrug-resistant Staphylococcus aureus along with decidedly potent synergy combinations with a standard drug, gentamycin, especially against gentamycin-resistant S. aureus NRS 10119. Cud C exhibited equipotent MIC (4 µg/mL) against a varied array of MDR strains comprising MRSA, VRSA, and VRE and was nontoxic toward eukaryotic cells with a sizable selectivity index (SI 25-50). Cud C displayed concentration-dependent bactericidal activity against planktonic cells, an excellent biofilm disruption property exceeding that of levofloxacin and vancomycin against preformed S. aureus biofilm, and an enhanced capability to kill intracellular S. aureus more potently than vancomycin, thus exemplifying its position as an antibacterial lead candidate. In addition, S. aureus was unable to generate resistance to Cud C even after exposure for more than 40 days, whereas it generated resistance to levofloxacin within ∼20 days of exposure. Therefore, the naturally occurring prenylflavone Cud C can be accounted for as one of the reasons for the reported antibacterial properties of the bark of A. hirsutus. Taken together, detailed biological studies propose that Cud C can be considered as an effective antibacterial drug candidate against MDR S. aureus, which is fast becoming a significant threat to public health worldwide.

Bioactive Diterpenes from the Brazilian Native Plant (Moquiniastrum pulchrum) and Their Application in Weed Control.

Even today, weeds continue to be a considerable problem for agriculture. The application of synthetic herbicides produces serious environmental consequences, and crops suffer loss of their activity due to the appearance of new resistant weed biotypes. Our aim is to develop new effective natural herbicides that improve the problem of resistance and do not harm the environment. This work is focused on a bioassay-guided isolation and the characterization of natural products present in Moquiniastrum pulchrum leaves with phytotoxic activity and its preliminary application in weeds. Moquiniastrum pulchrum was selected for two reasons: it is an abundant species in the Cerrado region (the second most important ecosystem in Brazil, after the Amazon)-the explanation behind its being a dominant species is a major focus of interest-and it has traditional employment in folk medicine. Six major compounds were isolated in this plant: one flavone and five diterpenes, two of which are described for the first time in the literature. Four of the six compounds exhibited phytotoxic activity in the bioassays performed. The results confirmed the phytotoxic potential of this plant, which had not been investigated until now.

Total Flavone of Abelmoschus manihot Ameliorates Stress-Induced Microbial Alterations Drive Intestinal Barrier Injury in DSS Colitis.

PURPOSE: Total flavone of Abelmoschus manihot (TFA), the effective constituents extracted from Flos Abelmoschus Manihot, has been reported to inhibit inflammation. However, the effect of TFA on ulcerative colitis (UC) progression in patients with depression is unknown. The purpose of our research was to explore the anti-UC effects of TFA in the context of depression in mice with UC by regulating the gut microbiota to drive the intestinal barrier. METHODS: In this study, chronic stress (CS) and dextran sodium sulfate (DSS) were used to induce depression and UC, respectively, in C57BL/6J mice. Fecal microbiota transplantation (FMT) was used to evaluate how treating mice modeling UC and depression with TFA effected their gut microbiota. RESULTS: Our results showed that TFA effectively improved UC aggravated by CS. In addition, TFA treatment improved the depression-like phenotype, the disturbed gut microbiota, and the intestinal barrier function in CS mice. It is worth noting that FMT from the CS mice to the receptor group further aggravated the damage of the intestinal barrier and the disturbance of the gut microbiota in the recipient DSS mice, thus further aggravating UC, however, treatment of the intervention of TFA in the CS fecal microbiota transplant with TFA also played its therapeutic outcome. CONCLUSION: Taken together, our results show that CS disrupts the gut microbiota, triggers intestinal barrier injury and aggravates DSS colitis, while TFA is a promising drug for the treatment of UC in patients with depression.

Hairy Roots of Scutellaria spp. (Lamiaceae) as Promising Producers of Antiviral Flavones.

We measured and studied the growth parameters and the qualitative and quantitative composition of the flavones of hairy roots of the Scutellaria genus: S. lateriflora, S. przewalskii and S. pycnoclada. Hairy roots were obtained using wild-type Agrobacterium rhizogenes A4 by co-cultivation of explants (cotyledons) in a suspension of Agrobacterium. The presence of the rol-genes was confirmed by PCR analysis. The hairy roots of the most studied plant from the Scutellaria genus, S. baicalensis, were obtained earlier and used as a reference sample. HPLC-MS showed the predominance of four main flavones (baicalin, baicalein, wogonin and wogonoside) in the methanol extracts of the studied hairy roots. In addition to the four main flavones, the other substances which are typical to the aerial part of plants were found in all the extracts: apigenin, apigetrin, scutellarin and chrysin-7-O-ß-d-glucuronide. According to the total content of flavones, the hairy roots of the studied skullcaps form the following series: S. przewalskii (33 mg/g dry weight) > S. baicalensis (17.04 mg/g dry weight) > S. pycnoclada (12.9 mg/g dry weight) > S. lateriflora (4.57 mg/g dry weight). Therefore, the most promising producer of anti-coronavirus flavones is S. przewalskii.

Metabolomics analysis of the soapberry (Sapindus mukorossi Gaertn.) pericarp during fruit development and ripening based on UHPLC-HRMS.

Soapberry (Sapindus mukorossi Gaertn.) is a multi-functional tree with widespread application in toiletries, biomedicine, biomass energy, and landscaping. The pericarp of soapberry can be used as a medicine or detergent. However, there is currently no systematic study on the chemical constituents of soapberry pericarp during fruit development and ripening, and the dynamic changes in these constituents still unclear. In this study, a non-targeted metabolomics approach using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) was used to comprehensively profile the variations in metabolites in the soapberry pericarp at eight fruit growth stages. The metabolome coverage of UHPLC-HRMS on a HILIC column was higher than that of a C18 column. A total of 111 metabolites were putatively annotated. Principal component analysis and hierarchical clustering analysis of pericarp metabolic composition revealed clear metabolic shifts from early (S1-S2) to late (S3-S5) development stages to fruit ripening stages (S6-S8). Furthermore, pairwise comparison identified 57 differential metabolites that were involved in 18 KEGG pathways. Early fruit development stages (S1-S2) were characterized by high levels of key fatty acids, nucleotides, organic acids, and phosphorylated intermediates, whereas fruit ripening stages (S6-S8) were characterized by high contents of bioactive and valuable metabolites, such as troxipide, vorinostat, furamizole, alpha-tocopherol quinone, luteolin, and sucrose. S8 (fully developed and mature stage) was the most suitable stage for fruit harvesting to utilize the pericarp. To the best of our knowledge, this was the first metabolomics study of the soapberry pericarp during whole fruit growth. The results could offer valuable information for harvesting, processing, and application of soapberry pericarp, as well as highlight the metabolites that could mediate the biological activity or properties of this medicinal plant.

Guaianolide Sesquiterpene Lactones from Centaurothamnus maximus.

Centaurothamnus maximus (family Asteraceae), is a leafy shrub indigenous to the southwestern Arabian Peninsula. With a paucity of phytochemical data on this species, we set out to chemically characterize the plant. From the aerial parts, two newly identified guaianolides were isolated: 3ß-hydroxy-4α(acetoxy)-4ß(hydroxymethyl)-8α-(4-hydroxy methacrylate)-1αH,5αH, 6αH-gual-10(14),11(13)-dien-6,12-olide (1) and 15-descarboxy picrolide A (2). Seven previously reported compounds were also isolated: 3ß, 4α, 8α-trihydroxy-4-(hydroxymethyl)-lαH, 5αH, 6ßH, 7αH-guai-10(14),11(13)-dien-6,12-olide (3), chlorohyssopifolin B (4), cynaropikrin (5), hydroxyjanerin (6), chlorojanerin (7), isorhamnetin (8), and quercetagetin-3,6-dimethyl ether-4'-O-ß-d-pyranoglucoside (9). Chemical structures were elucidated using spectroscopic techniques, including High Resolution Fast Atom Bombardment Mass Spectrometry (HR-FAB-MS), 1D NMR; 1H, 13C NMR, Distortionless Enhancement by Polarization Transfer (DEPT), and 2D NMR (1H-1H COSY, HMQC, HMBC) analyses. In addition, a biosynthetic pathway for compounds 1-9 is proposed. The chemotaxonomic significance of the reported sesquiterpenoids and flavonoids considering reports from other Centaurea species is examined.

Flavones from Combretum quadrangulare Growing in Vietnam and Their Alpha-Glucosidase Inhibitory Activity.

Combretum quadrangulare Kurz is widely used in folk medicine in Eastern Asia and is associated with various ethnopharmacological properties including hepatoprotective, antipyretic, analgesic, antidysenteric, and anthelmintic activities. Previous phytochemical investigations reported the presence of numerous triterpenes (mostly cycloartanes, ursanes, lupanes, and oleananes) along with dozens of flavonoids. However, the extracts of C. quadrangulare and isolated flavonoids have not been evaluated for their alpha-glucosidase inhibition. In the frame of our efforts dedicated to the chemical investigation of Vietnamese medicinal plants and their biological activities, a phytochemical study of the MeOH extract of the leaves of C. quadrangulare using bioactive guided isolation was undertaken. In this paper, the isolation and structure elucidation of twelve known compounds, 5-hydroxy-3,7,4'-trimethoxyflavone (1), ayanin (2), kumatakenin (3), rhamnocitrin (4), ombuin (5), myricetin-3,7,3',5'-tetramethyl ether (6), gardenin D (7), luteolin (12), apigenin (13), mearnsetin (14), isoorientin (15), and vitexin (16) were reported. Bromination was applied to compounds 2 and 3 to provide four new synthetic analogues 8-11. All isolated and synthesized compounds were evaluated for alpha-glucosidase inhibition and antibacterial activity. Compounds 4 and 5 showed moderate antibacterial activity against methicillin-resistant Staphylococcus aureus while others were inactive. All compounds failed to reveal any activity toward extended spectrum beta-lactamase-producing Escherichia coli. Compounds 2, 4, 6-9, and 11-14 showed good alpha-glucosidase inhibition with IC50 values in the range of 30.5-282.0 µM. The kinetic of enzyme inhibition showed that 8 and 11 were noncompetitive type inhibition against alpha-glucosidase. In silico molecular docking model indicated that compounds 8 and 11 were potential inhibitors against enzyme α-glucosidase.

Bioassay-Guided Identification of the Antiproliferative Compounds of Cissus trifoliata and the Transcriptomic Effect of Resveratrol in Prostate Cancer Pc3 Cells.

The bioassay-guided fractionation of a CHCl3-MeOH extract from the stems of Cissus trifoliata identified an active fraction against PC3 prostate cancer cells. The treatment for 24 h showed an 80% reduction in cell viability (p ≤ 0.05) by a WST-1 assay at a concentration of 100 µg/mL. The HPLC-QTOF-MS analysis of the fraction showed the presence of coumaric and isoferulic acids, apigenin, kaempferol, chrysoeriol, naringenin, ursolic and betulinic acids, hexadecadienoic and octadecadienoic fatty acids, and the stilbene resveratrol. The exposure of PC3 cells to resveratrol (IC25 = 23 µg/mL) for 24 h induced significant changes in 847 genes (Z-score ≥ ±2). The functional classification tool of the DAVID v6.8 platform indicates that the underlying molecular mechanisms against the proliferation of PC3 cells were associated (p ≤ 0.05) with the process of differentiation and metabolism. These findings provide experimental evidence suggesting the potential of C. trifoliata as a promising natural source of anticancer compounds.

Sesquiterpenoids from Chrysanthemum indicum with Inhibitory Effects on NO Production.

Three new guaianolide lactones (1-3) and four new 9-oxonerolidol glucosides (5-8) together with 20 known compounds were isolated from the MeOH extract of the flowers of Chrysanthemum indicum. Their structures were elucidated based on the interpretation of NMR, HRESIMS, and electronic circular dichroism (ECD) data along with acid hydrolysis. Of the isolates, sesquiterpenoids 1-4 and 15 and flavones 17 and 18 exhibited inhibitory effects on lipopolysaccharide (LPS)-induced nitric oxide production in RAW 264.7 cells with IC50 values in the range 0.2-27.0 µM.

Anti-inflammatory Properties of Ethanolic Extract and 2″-O-ß-D-Glucopyranosyl-vitexin Obtained from Alternanthera tenella Colla Whole Plant.

Six flavonoids were identified and isolated from the ethanolic extract of Alternanthera tenella Colla (Amaranthaceae) whole plant (EEAT) including 2″-O-ß-D-glucopyranosyl-vitexin (A19). Flavonoids have anti-inflammatory activity; however, the 2″-O-ß-D-glucopyranosyl-vitexin anti-inflammatory property was not totally explored. The aim of the present study was to investigate the anti-inflammatory effects of ethanolic extract from A. tenella whole plant and isolated flavone C-glycoside A19 in models of inflammation. The oral administration (p.o.) of EEAT (30, 100, and 300 mg/kg), A19 (0.1, 1, and 10 mg/kg), and prednisolone (3 mg/kg) were tested against the carrageenan-induced paw edema in Swiss mice. The EEAT (100 mg/kg, p.o.), A19 (1 mg/kg, p.o.), and prednisolone (3 mg/kg, p.o.) were tested in the zymosan-articular inflammation, carrageenan-pleurisy, and complete Freund's adjuvant (CFA) models in Swiss mice. In silico analysis and search for structural relationships between vitexin derivatives flavones present in the EEAT and TNF-α inhibitors were performed. EEAT, A19, and prednisolone significantly inhibited (i) edema, mechanical hyperalgesia in carrageenan-induced paw inflammation; (ii) leukocyte migration and protein extravasation in carrageenan-induced pleurisy; (iii) knee edema, mechanical hyperalgesia, and leukocyte migration in articular inflammation induced by zymosan. Still the CFA induced the increase in myeloperoxidase and N-acetylglucosaminidase activities, EEAT, A19, and prednisolone significantly inhibited these enzymes. The in silico analysis showed that molecules with similar structure to apigenin and vitexin have a potential inhibition on the TNF system. This study confirms the anti-inflammatory properties of EEAT and A19. The C-glycosylated flavone A19 could be responsible for the EEAT anti-edematogenic and anti-hyperalgesic effects and a potential TNF-α inhibitor.

The phytochemistry and pharmacology of medicinal fungi of the genus Phellinus: a review.

Phellinus Quél is one of the largest genera of Hymenochaetaceae, which is comprised of about 220 species. Most Phellinus macro-fungi are perennial lignicolous mushrooms, which are widely distributed on Earth. Some Phellinus fungi are historically recorded as traditional medicines used to treat various diseases in eastern Asian countries, especially China, Japan and Korean. Previous phytochemical studies have revealed that Phellinus fungi produce diverse secondary metabolites, which mainly contain polysaccharides, flavones, coumarins, terpenes, steroids, and styrylpyranones. Pharmacological documents have demonstrated that Phellinus mushrooms and their compounds have a variety of bioactivities, such as anti-tumor, immunomodulation, anti-oxidative and anti-inflammation, anti-diabetes, neuro-protection, and anti-viral effects. This review surveys the literature reporting the isolation, characterization, and bioactivities of secondary metabolites from the fungi of the genus Phellinus, focusing on studies published in the literature up to April 2020. Herein, a total of more than 300 compounds from 13 Phellinus species and their isolation, characterization, chemistry, pharmacological activities, and relevant molecular mechanisms are comprehensively summarized.

Antioxidative Effects of Chrysoeriol via Activation of the Nrf2 Signaling Pathway and Modulation of Mitochondrial Function.

Retinal pigment epithelium (RPE) cell dysfunction caused by excessive oxidative damage is partly involved in age-related macular degeneration, which is among the leading causes of visual impairment in elderly people. Here, we investigated the protective role of chrysoeriol against hydrogen peroxide (H2O2)-induced oxidative stress in RPE cells. The cellular viability, reactive oxygen species (ROS) generation, and mitochondrial function of retinal ARPE-19 cells were monitored under oxidative stress or pre-treatment with chrysoeriol. The expression levels of mitochondrial-related genes and associated transcription factors were assessed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Moreover, the protein expression of antioxidant signal molecules was characterized by Western blot analysis. Chrysoeriol significantly increased cell viability, reduced ROS generation, and increased the occurrence of antioxidant molecules in H2O2-treated ARPE-19 cells. Additionally, mitochondrial dysfunction caused by H2O2-induced oxidative stress was also considerably diminished by chrysoeriol treatment, which reduced the mitochondrial membrane potential (MMP) and upregulated mitochondrial-associated genes and proteins. Chrysoeriol also markedly enhanced key transcription factors (Nrf2) and antioxidant-associated genes (particularly HO-1 and NQO-1). Therefore, our study confirms the protective effect of chrysoeriol against H2O2-induced oxidative stress in RPE cells, thus confirming that it may prevent mitochondrial dysfunction by upregulating antioxidant-related molecules.

[Structure Activity Relationship Study of Polymethoxylated Flavones Targeted Retinal Müller Cells for Prevention of Retinal Diseases].

Diabetic retinopathy (DR) is a retinal disease representing one of the main causes of vision loss in developed countries. In the early stage of DR, disruption of blood retinal barrier (BRB) is observed, and it will lead to vascular permeability and visual impairment. Therefore, protection against the breakdown of BRB may be useful strategy for prevention of DR. Matrix metalloproteinases (MMPs) plays an important role in the degradation of extracellular matrix proteins. In DR, they attribute to increased vascular permeability by degrading the junction proteins, such as occuldin and cadherin that are important to maintain the BRB junction complex. Müller cells constitute the main glial cells of the retina and are involved in many retinal functions. They are reported to be one of the MMP-producing cells in the retina. In this symposium review, I present the molecular mechanism of MMP expression in retinal Müller cells. In addition, I would like to introduce polymethoxylated flavones, nobiletin and the derivatives isolated from natural resource as novel MMP inhibitors, which may be applicable to prevention of DR.

Rapid screening and isolation of antioxidants from Eupatorium lindleyanum DC. using CCC target-guided by on-line HPLC-DPPH assay.

Counter-current chromatography (CCC) target-guided by on-line HPLC with post-column DPPH assay was established for efficient screening and isolation of large amount of antioxidants from Eupatorium lindleyanum DC. On-line HPLC with post-column DPPH reaction was used to screen the antioxidants and optimize the biphasic solvent system of CCC, then the targeted peaks were purified using CCC. In the present study, three compounds, nepetin, cirsiliol and jaceosidin, were targeted and successively separated from n-butanol fraction of E. lindleyanum DC. by this strategy. All three compounds showed strong DPPH radical scavenging activity. These results confirmed that the strategy would be an efficient and effective method to isolate antioxidants from complex mixtures.

Network pharmacology predicted HDAC6 as a potential target of flavones from Daphne giraldii on hepatocellular carcinoma.

Daphne giraldii Nitsche, belongs to Daphne genus, has been reported to exert anti-tumor activities. Our previous study suggested that flavones from Daphne giraldii have significant inhibitory effects on hepatocellular carcinoma (HCC) cells. However, the potential target of this type flavone was still unknown. In this study, 74 flavonoids compounds of Daphne giraldii and 41 potential targets of HCC were analyzed by the network, the most potential target was histone deacetylase 6 (HDAC6). Considering the cytotoxicity, compound 70 (Daphnegiravone D, DGD) was chosen for further confirmation. Molecular docking study revealed that DGD formed high binding affinity with HDAC6. Concomitantly, pharmacological studies indicated that DGD could inhibit the expression of HDAC6 in vitro and in vivo. In this study, network pharmacology along with experimental validation predicted and verified HDAC6 as one of potential targets of flavones, these investigations provide a new insight for further study of Daphne giraldii on HCC treatment.

Polymethoxyflavones from citrus inhibited gastric cancer cell proliferation through inducing apoptosis by upregulating RARß, both in vitro and in vivo.

In order to discover the active anti-tumor ingredients during the flavonoids separation process of Ougan (Citrus reticulata cv. Suavissima), gastric cancer cell lines including AGS, BGC-823, and SGC-7901 were employed to evaluate the proliferation inhibition abilities of Ougan extracts, flavanone components, polymethoxyflavone components, neohesperidin, nobiletin, tangeretin, and 5-demethylnobiletin. Quantitative real-time PCR was used to detect the expression of three retinoic acid receptor genes, including RARA, RARB, and RARG. Western blot and immunohistochemistry were used to detect protein expressions. The results showed that the polymethoxyflavone components and the PMFs monomers inhibited the proliferation of three gastric cancer cell lines and induced apoptosis. The mechanism exploration found that PMFs up-regulated the expression of the RARB gene selectively and activated the Caspase3, 9, and PARP1 proteins. In addition to 5-demethylnobiletin, other PMFs also upregulated the expression of cleaved Caspase8. The mechanism was preliminarily verified by a RARß inhibitor AGN 193109. Moreover, a nude mice tumor xenograft model confirmed the tangeretin could exhibit in vivo anti-tumor effect through inducing apoptosis and upregulating RARß protein. All result suggested that tangeretin may be a potentially novel, safe and effective drugs with less toxicity and lesser side effects for gastric cancer therapeutics.