Xin-Yi-Qing-Fei-Tang and its critical components reduce asthma symptoms by suppressing GM-CSF and COX-2 expression in RBL-2H3 cells

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) XYQFT is composed of 10 herbs. According to the NHIRD, XYQFT is one of the top ten most commonly used TCM prescriptions for asthma treatment.

AIM OF THE STUDY

The aim of this study was to explore whether XYQFT reduces asthma symptoms in a mouse model of chronic asthma and determine the immunomodulatory mechanism of mast cells.

MATERIALS AND METHODS

BALB/c mice were intratracheally (it) stimulated with 40 μL (2.5 μg/μL) of Dermatophagoides pteronyssinus (Der p) once a week for 6 consecutive weeks and orally administered XYQFT at 1 g/kg 30 min before Der p stimulation. Airway hypersensitivity, inflammatory cells in the BALF and total IgE in the blood were assessed in mice. In addition, RBL-2H3 cells (mast cells) were stimulated with DNP-IgE, after which different concentrations of XYQFT were added for 30 min to evaluate the effect of XYQFT on the gene expression and degranulation of DNP-stimulated RBL-2H3 cells. After the compounds in XYQFT were identified using LC‒MS/MS, the PBD method was used to identify the chemical components that inhibited the expression of the GM-CSF and COX-2 genes in mast cells.

RESULTS

The airway hypersensitivity assay demonstrated that XYQFT significantly alleviated Der p-induced airway hypersensitivity. Moreover, cell counting and typing of bronchoalveolar lavage fluid revealed a significant reduction in Der p-induced inflammatory cell infiltration with XYQFT treatment. ELISA examination further indicated a significant decrease in Der p-induced total IgE levels in serum following XYQFT administration. In addition, XYQFT inhibited the degranulation and expression of genes (IL-3, IL-4, ALOX-5, IL-13, GM-CSF, COX-2, TNF-α, and MCP-1) in RBL-2H3 cells after DNP stimulation. The compounds timosaponin AIII and genkwanin in XYQFT were found to be key factors in the inhibition of COX-2 and GM-CSF gene expression in mast cells.

CONCLUSION

By regulating mast cells, XYQFT inhibited inflammatory cell infiltration, airway hypersensitivity and specific immunity in a mouse model of asthma. In addition, XYQFT synergistically inhibited the expression of the GM-CSF and COX-2 genes in mast cells through timosaponin AIII and genkwanin.

Genkwanin alleviates intervertebral disc degeneration via regulating ITGA2/PI3K/AKT pathway and inhibiting apoptosis and senescence

Intervertebral disc degeneration (IVDD) is a progressive degenerative disease influenced by various factors. Genkwanin, a known anti-inflammatory flavonoid, has not been explored for its potential in IVDD management. This study aims to investigate the effects and mechanisms of genkwanin on IVDD. In vitro, cell experiments revealed that genkwanin dose-dependently inhibited Interleukin-1β-induced expression levels of inflammatory factors (Interleukin-6, inducible nitric oxide synthase, cyclooxygenase-2) and degradation metabolic protein (matrix metalloproteinase-13). Concurrently, genkwanin upregulated the expression of synthetic metabolism genes (type II collagen, aggrecan). Moreover, genkwanin effectively reduced the phosphorylation of phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin, mitogen-activated protein kinase (MAPK), and nuclear factor-κB (NF-κB) pathways. Transcriptome sequencing analysis identified integrin α2 (ITGA2) as a potential target of genkwanin, and silencing ITGA2 reversed the activation of PI3K/AKT pathway induced by Interleukin-1β. Furthermore, genkwanin alleviated Interleukin-1β-induced senescence and apoptosis in nucleus pulposus cells. In vivo animal experiments demonstrated that genkwanin mitigated the progression of IVDD in the rat model through imaging and histological examinations. In conclusion, This study suggest that genkwanin inhibits inflammation in nucleus pulposus cells, promotes extracellular matrix remodeling, suppresses cellular senescence and apoptosis, through the ITGA2/PI3K/AKT, NF-κB and MAPK signaling pathways. These findings indicate that genkwanin may be a promising therapeutic candidate for IVDD.

Antioxidant, anti-inflammatory, and anti-apoptotic effects of genkwanin against aflatoxin B1-induced testicular toxicity

Aflatoxin B1 (AFB1) is the most hazardous aflatoxin that causes significant damage to the male reproductive system. Genkwanin (GNK) is a bioactive flavonoid that shows antioxidant and anti-inflammatory potential. Therefore, the current study was planned to evaluate the effects of GNK against AFB1-induced testicular toxicity. Forty-eight male rats were distributed into four groups (n = 12 rats). AFB1 (50 μg/kg) and GNK (20 mg/kg) were administered to the rats for eight weeks. Results of the current study revealed that AFB1 exposure induced adverse effects on the Nrf2/Keap1 pathway and reduced the expressions and activities of antioxidant enzymes. Additionally, it increased the levels of oxidative stress markers. Furthermore, expressions of steroidogenic enzymes were down-regulated by AFB1 intoxication. Besides, AFB1 exposure reduced the levels of gonadotropins and plasma testosterone, which subsequently reduced the epididymal sperm count, motility, and hypo-osmotic swelled (HOS) sperms, while increasing the number of dead sperms and causing morphological anomalies of the head, midpiece, and tail of the sperms. In addition, AFB1 decreased the activities of testicular function marker enzymes and the levels of inflammatory markers. Moreover, it severely affected the apoptotic profile by up-regulating the expressions of Bax and Casp3, while down-regulating the Bcl2 expression. Besides, AFB1 significantly damaged the histoarchitecture of testicular tissues. However, GNK treatment reversed all the AFB1-induced damages in the rats. Taken together, the current study reports the potential use of GNK as a therapeutic agent to prevent AFB1-induced testicular toxicity due to its antioxidant, anti-inflammatory, and anti-apoptotic properties.

Genkwanin: An emerging natural compound with multifaceted pharmacological effects

Plant bioactive molecules could play key preventive and therapeutic roles in chronological aging and the pathogenesis of many chronic diseases, often accompanied by increased oxidative stress and low-grade inflammation. Dietary antioxidants, including genkwanin, could decrease oxidative stress and the expression of pro-inflammatory cytokines or pathways. The present study is the first comprehensive review of genkwanin, a methoxyflavone found in several plant species. Indeed, natural sources, and pharmacokinetics of genkwanin, the biological properties were discussed and highlighted in detail. This review analyzed and considered all original studies related to identification, isolation, quantification, investigation of the biological and pharmacological properties of genkwanin. We consulted all published papers in peer-reviewed journals in the English language from the inception of each database to 12 May 2023. Different phytochemical demonstrated that genkwanin is a non-glycosylated flavone found and isolated from several medicinal plants such as Genkwa Flos, Rosmarinus officinalis, Salvia officinalis, and Leonurus sibiricus. In vitro and in vivo biological and pharmacological investigations showed that Genkwanin exhibits remarkable antioxidant and anti-inflammatory activities, genkwanin, via activation of glucokinase, has shown antihyperglycemic activity with a potential role against metabolic syndrome and diabetes. Additionally, it revealed cardioprotective and neuroprotective properties, thus reducing the risk of cardiovascular diseases and assisting against neurodegenerative diseases. Furthermore, genkwanin showed other biological properties like antitumor capability, antibacterial, antiviral, and dermato-protective effects. The involved mechanisms include sub-cellular, cellular and molecular actions at different levels such as inducing apoptosis and inhibiting the growth and proliferation of cancer cells. Despite the findings from preclinical studies that have demonstrated the effects of genkwanin and its diverse mechanisms of action, additional research is required to comprehensively explore its therapeutic potential. Primarily, extensive studies should be carried out to enhance our understanding of the molecule's pharmacodynamic actions and pharmacokinetic pathways. Moreover, toxicological and clinical investigations should be undertaken to assess the safety and clinical efficacy of genkwanin. These forthcoming studies are of utmost importance in fully unlocking the potential of this molecule in the realm of therapeutic applications.

Metabolic engineering and optimization of Escherichia coli co-culture for the de novo synthesis of genkwanin

Genkwanin has various significant roles in nutrition, biomedicine, and pharmaceutical biology. Previously, this compound was chiefly produced by plant-originated extraction or chemical synthesis. However, due to increasing concern and demand for safe food and environmental issues, the biotechnological production of genkwanin and other bioactive compounds based on safe, cheap, and renewable substrates has gained much interest. This paper described recombinant Escherichia coli-based co-culture engineering that was reconstructed for the de novo production of genkwanin from d-glucose. The artificial genkwanin biosynthetic chain was divided into 2 modules in which the upstream strain contained the genes for synthesizing p-coumaric acid from d-glucose, and the downstream module contained a gene cluster that produced the precursor apigenin and the final product, genkwanin. The Box-Behnken design, a response surface methodology, was used to empirically model the production of genkwanin and optimize its productivity. As a result, the application of the designed co-culture improved the genkwanin production by 48.8 ± 1.3 mg/L or 1.7-fold compared to the monoculture. In addition, the scale-up of genkwanin bioproduction by a bioreactor resulted in 68.5 ± 1.9 mg/L at a 48 hr time point. The combination of metabolic engineering and fermentation technology was therefore a very efficient and applicable approach to enhance the production of other bioactive compounds.

Uncovering the efficacy and mechanisms of Genkwa flos and bioactive ingredient genkwanin against L. monocytogenes infection

ETHNOPHARMACOLOGICAL RELEVANCE

Genkwa flos (yuanhua in Chinese), the dried flower buds of the plant Daphne genkwa Siebold & Zucc., as a traditional herb widely used for the treatment of inflammation-related symptoms and diseases, with the efficacies of diuretic, phlegm-resolving and cough suppressant.

AIM OF THE STUDY

Traditional Chinese Medicine (TCM) is presumed to be of immense potential against pathogens infection. Whereas, the potential efficacy and mechanisms of Genkwa flos against L. monocytogenes infection has not been extensively explored. The present study aimed to identify the bioactive ingredients of Genkwa flos against L. monocytogenes infection and to delineate the underlying mechanisms of action.

MATERIALS AND METHODS

Bioinformatics approach at protein network level was employed to investigate the therapeutic mechanisms of Genkwa flos against L. monocytogenes infection. And hemolysis inhibition assay, cytoprotection test, western blotting, oligomerization assay and molecular docking analysis were applied to substantiate the multiple efficacies of Genkwa flos and the bioactive ingredient genkwanin. Histopathological analysis and biochemistry detection were conducted to evaluate the in vivo protective effect of genkwanin.

RESULTS

Network pharmacology and experimental validation revealed that Traditional Chinese Medicine (TCM) Genkwa flos exhibited anti-L. monocytogenes potency and was found to inhibit the hemolytic activity of LLO. Bioactive ingredient genkwanin interfered with the pore-forming activity of LLO by engaging the active residues Tyr414, Tyr98, Asn473, Val100, Tyr440 and Val438, and thereby attenuated LLO-mediated cytotoxicity. Consistent with the bioinformatics prediction, exposed to genkwanin could upregulate the Nrf2 level and promote the translocation of Nrf2. In vivo, genkwanin oral administration (80 mg/kg) significantly protected against systemic L. monocytogenes infection, as evidenced by reduced myeloperoxidase (MPO) and malondialdehyde (MDA) levels, increased mice survival rate by 30% and decreased pathogen colonization.

CONCLUSION

Our study demonstrated that Genkwa flos is a potential anti-L. monocytogenes TCM, highlighted the therapeutic potential of Genkwa flos active ingredient genkwanin by targeting the pore-forming cytolysin LLO and acting as a promising antioxidative candidate against L. monocytogenes infection.

Genkwanin Alleviates Mitochondrial Dysfunction and Oxidative Stress in a Murine Model of Experimental Colitis: The Participation of Sirt1

OBJECTIVE

Genkwanin is a biologically active O-methylated flavone extracted from Daphne genkwa. An increasing number of studies have described the modulatory effects of genkwanin on human diseases, including antitumor, anti-inflammatory, and antioxidant activities. However, little is known about whether genkwanin might be a therapeutic agent for inflammatory bowel disease or its possible underlying mechanisms.

MATERIALS AND METHODS

Forty C57BL/6 male mice were orally administered dextran sulfate sodium (DSS) to generate the colitis model, and genkwanin was orally administered at the indicated concentrations. Body weight, disease activity index, colon length, and H&E staining were used to evaluate colitis. Oxidative stress and antioxidant levels were measured by detecting ROS generation and malondialdehyde, superoxide dismutase and glutathione levels. The levels of proinflammatory cytokines (TNF-α, IL-1β, IFNγ and IL-6) were measured using ELISAs. Cell viability was determined using the CCK-8 assay. Mitochondrial function was evaluated by measuring the oxygen consumption rate, mtDNA content, and activities of electron transfer chain (ETC) complexes I, II, and IV. The expression of SIRT1, Nrf2 and its target genes was determined using qRT-PCR and western blotting. SIRT1 was depleted by lentivirus-mediated knockdown.

RESULTS

In this study, oral administration of genkwanin alleviated colitis induced by oral administration of DSS in mice, as evidenced by reduced weight loss, colon length shortening and histopathology scores. Furthermore, genkwanin relieved oxidative stress and reduced the production of proinflammatory cytokines. In vitro assays revealed that genkwanin administration inhibited reactive oxygen species (ROS) production and improved mitochondrial function in human intestinal epithelial cells. Genkwanin also upregulated the expression of SIRT1, and lentivirus-mediated SIRT1 knockdown partially abrogated the protective effect of genkwanin on oxidative stress and mitochondrial dysfunction.

CONCLUSIONS

Findings from our murine model and cell culture experiments provide a promising basis for genkwanin to be studied as a treatment for IBD in clinical trials.

Genkwanin suppresses MPP+-induced cytotoxicity by inhibiting TLR4/MyD88/NLRP3 inflammasome pathway in a cellular model of Parkinson's disease

Parkinson's disease (PD) is a complicated multifactorial neurodegenerative disorder. Oxidative stress, neuroinflammatory response, and activation of apoptosis have been proposed to be tightly involved in the pathogenesis of PD. Genkwanin is a typical bioactive non-glycosylated flavonoid with anti-inflammatory and anti-oxidant activities. However, the effect of genkwanin on PD remains unclear. Cell viability, lactate dehydrogenase (LDH) release, caspase-3/7 activity, and apoptosis was evaluated by MTT, LDH release assay, caspase-3/7 activity assay, and TUNEL assay, respectively. The secretion of prostaglandin E₂ (PGE₂), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 were measured by respective commercial ELISA kits. The mRNA expression of TNF-α, IL-1β, and IL-6 was detected by qRT-PCR. The protein levels of cycloxygenase-2 (COX-2), toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and NOD-like receptor (NLR) protein: 3 (NLRP3) were determined by western blot analysis. Genkwanin at concentrations less than 40 μM had no impact on cell viability and LDH release. Genkwanin suppressed MPP⁺-induced neuroinflammation in SH-SY5Y cells. MPP⁺ treatment inhibited cell viability, increased LDH release, apoptosis, and ROS generation, and reduced superoxide dismutase (SOD) activity in SH-SY5Y cells, which were abolished by genkwanin treatment. Genkwanin suppressed MPP⁺-induced activation of TLR4/MyD88/NLRP3 inflammasome pathway in SH-SY5Y cells. TLR4 overexpression weakened the anti-inflammatory and anti-neurotoxicity of genkwanin in SH-SY5Y cells. In conclusion, genkwanin attenuated neuroinflammation and neurotoxicity by inhibiting TLR4/MyD88/NLRP3 inflammasome pathway in MPP⁺-induced cellular model of PD.

Anti-rheumatoid arthritis effects of flavonoids from Daphne genkwa

OBJECTIVE

This study aims to select the most effective anti-Rheumatoid Arthritis (RA) component of flavonoids from Daphne genkwa Sieb. et Zucc. by anti-inflammatory and immunomodulatory effects in vitro, and to elucidate the mechanism.

METHODS

The anti-inflammatory and immunomodulatory effects of total flavonoids (TF) and four flavonoid components (genkwanin, hydroxygenkwanin, luteolin and apigenin) were determined by pharmacological approach in LPS-induced RAW 264.7 macrophages and ConA-induced T lymphocytes. Principal component analysis (PCA) was used to obtain the optimal anti-RA component in vitro. Western blot and real-time quantitative PCR (q-PCR) were used to explore the mechanisms. Finally, the in vitro anti-RA effect was verified by human rheumatoid arthritis fibroblast-like synoviocytes (FLSs).

RESULTS

TF and four flavonoids significantly reduced the expressions of NO, iNOS, TNF-α, IL-6, IFN-γ and IL-2. PCA showed that genkwanin was the most effective anti-RA component in vitro. Genkwanin inhibited nuclear factor-κB (NF-κB) pathway by decreasing the phosphorylation levels of IKK, IκB and NF-κB, and down-regulated the expressions of iNOS, COX-2 and IL-6 mRNA. Genkwanin also inhibited the abnormal proliferation of FLSs and down-regulated the secretions of NO and IL-6.

CONCLUSION

The most effective anti-RA component was genkwanin. Genkwanin exerts anti-RA effect through down-regulating the activation of NF-κB pathway and mRNA expressions of inflammatory mediators, and also by inhibiting the abnormal proliferation of FLSs and its NO and IL-6 secretion levels.

Genkwanin ameliorates adjuvant-induced arthritis in rats through inhibiting JAK/STAT and NF-κB signaling pathways

BACKGROUND

Genkwanin is a flavone isolated from the traditional Chinese herb Daphne genkwa. Our previous work proved that four flavonoids (including genkwanin) isolated from D. genkwa (FFD) significantly improved the symptoms of arthritis in rat models. Recent studies have revealed that genkwanin exhibited anti-inflammatory and immunomodulatory activities, both of which were closely related to the pathology of rheumatoid arthritis (RA). Therefore, studying the anti-RA effects and mechanisms of genkwanin may give us insight into FFD's therapeutic effects on RA.

PURPOSE

This study aimed to investigate the anti-rheumatoid arthritis activity of genkwanin on adjuvant-induced arthritis (AIA) model in rats and explore the underlying mechanisms.

METHODS

The anti-rheumatoid arthritis activity of genkwanin was evaluated on AIA rat model by determining the paw swelling degrees and arthritis index scores, along with histopathological analysis of joint tissues. The serum cytokine levels were measured by ELISA method, and serum NO levels were measured by Griess method. The expression and phosphorylation levels of proteins in JAK/STAT and NF-κB signaling pathways were determined by western blot analysis and immunohistochemistry analysis.

RESULTS

Genkwanin significantly decreased the paw swelling and arthritis index in AIA rats and also decreased the inflammation and bone destruction in joint tissues. The serum TNF-α, IL-6, and NO concentrations were markedly reduced while the IL-10 concentration was markedly increased with the treatment of genkwanin. Genkwanin inhibited the activation of JAK/STAT and NF-κB signaling pathways in synovial tissues of AIA rats.

CONCLUSION

Genkwanin exerted anti-rheumatoid arthritis effects on AIA rats through inhibiting the activation of JAK/STAT and NF-κB signaling pathways. The results obtained in this work lead us to suggest that Genkwanin could play a crucial role on the previously demonstrated anti-rheumatoid arthritis activity of flavonoid extract of D. genkwa (namely FFD).

Inhibition of African swine fever virus infection by genkwanin

African swine fever virus (ASFV) is the causative agent of an economically important disease of pigs for which no effective vaccines or antiviral drugs are available. Recent outbreaks in EU countries and China have highlighted the critical role of antiviral research in combating this disease. We have previously shown that apigenin, a naturally occurring plant flavone, possesses significant anti-ASFV activity. However, apigenin is practically insoluble in highly polar solvents and it occurs typically in derivative forms in plants. Here we screened several commercially available apigenin derivatives for their ability to inhibit ASFV Ba71V strain in Vero cells. Among them, genkwanin showed significant inhibition of ASFV, reducing viral titer from 6.5 ± 0.1 to 4.75 ± 0.25 log TCID/ml in a dose-dependent manner (IC₅₀ = 2.9 μM and SI = 205.2). Genkwanin reduced the levels of ASFV early and late proteins, as well as viral DNA synthesis. Our further experiments indicated that genkwanin is able to inhibit ASFV infection at entry and egress stages. Finally, genkwanin displayed potent antiviral activity against highly virulent ASFV isolate currently circulating in Europe and China, emphasizing its value as candidate for antiviral drug development.

Rhamnocitrin isolated from Prunus padus var. seoulensis: A potent and selective reversible inhibitor of human monoamine oxidase A

Three flavanones and two flavones were isolated from the leaves of Prunus padus var. seoulensis by the activity-guided screening for new monoamine oxidase (MAO) inhibitors. Among the compounds isolated, rhamnocitrin (5) was found to potently and selectively inhibit human MAO-A (hMAO-A, IC₅₀ = 0.051 µM) and effectively inhibit hMAO-B (IC₅₀ = 2.97 µM). The IC₅₀ value of 5 for hMAO-A was the lowest amongst all natural flavonoids reported to date, and the potency was 20.2 times higher than that of toloxatone (1.03 µM), a marketed drug. In addition, 5 reversibly and competitively inhibited hMAO-A and hMAO-B with K_i values of 0.030 and 0.91 µM, respectively. Genkwanin (4) was also observed to strongly inhibit hMAO-A and hMAO-B (IC₅₀ = 0.14 and 0.35 µM, respectively), and competitively inhibit hMAO-A and hMAO-B (K_i = 0.097 and 0.12 µM, respectively). Molecular docking simulation reveals that the binding affinity of 5 with hMAO-A (-18.49 kcal/mol) is higher than that observed with hMAO-B (0.19 kcal/mol). Compound 5 interacts with hMAO-A at four possible residues (Asn181, Gln215, Thr336, and Tyr444), while hMAO-B forms a single hydrogen bond at Glu84. These findings suggest that compound 5 as well as 4 can be considered as novel potent and reversible hMAO-A and/or hMAO-B inhibitors or useful lead compounds for future development of hMAO inhibitors in neurological disorder therapies.

Genkwanin nanosuspensions: a novel and potential antitumor drug in breast carcinoma therapy

Recently, genkwanin (GKA) has been shown to display in vitro antitumor activity against some cancer cells, but its poor solubility restricted the in vivo study and further investigation of its antitumor therapeutic efficacy. In this paper, genkwanin nanosuspensions (GKA-NSps) were successfully prepared using D-alpha tocopherol acid polyethylene glycol succinate (TPGS) as a stabilizer using the precipitation-homogenization method. The obtained GKA-NSps had an average particle size of 183.1 ± 4.4 nm, a PDI value of 0.16 ± 0.07, a zeta potential of −16.2 ± 0.1 mV, and a drug loading content of 49.36 ± 0.14%. GKA-NSps showed spherical morphology and very good stability in normal saline, phosphate buffer saline (PBS, pH 7.4), 5% glucose, artificial gastric juice, artificial intestinal juice and plasma; thus, it is suitable for both oral and intravenous administration. The resultant GKA-NSps displayed sustained drug release behavior and stronger in vitro cytotoxicity against 4T1, MCF-7, MDA-MB-453, HeLa, HepG2, BT474, and A549 cells than free GKA. The in vivo study in MCF-7 tumor-bearing nude mice indicated that GKA-NSps (60 mg/kg, i.v.) achieved similar therapeutic efficacy as PTX injection (8 mg/kg, i.v.) (62.09% vs. 61.27%), while the minimal lethal dose was more than 320 mg/kg, indicating good safety. By using nanotechnology, our study suggested that some antitumor flavonoids of low potency, such as GKA, are promising as safe but effective anticancer drugs.

Absorption Properties of Luteolin and Apigenin in Genkwa Flos Using In Situ Single-Pass Intestinal Perfusion System in the Rat

The flower bud of Daphne genkwa (Genkwa Flos) is a commonly used herbal medicine in Asian countries. Luteolin and apigenin are two recognized active flavonoids in Genkwa Flos. The aim of this study was to investigate the intestinal absorption mechanisms of Genkwa Flos flavonoids using in situ single-pass intestinal perfusion rat model. Using HPLC, we determined its major effective flavonoids luteolin, apigenin, as well as, hydroxygenkwanin and genkwanin in biological samples. The intestinal absorption mechanisms of the total flavonoids in Genkwa Flos (TFG) were investigated using in situ single-pass intestinal perfusion rat model. Comparing the TFG absorption rate in different intestinal segments, data showed that the small intestine absorption was significantly higher than that of the colon ([Formula: see text]). Compared with duodenum and ileum, the jejunum was the best small intestinal site for TFG absorption. The high TFG concentration (61.48[Formula: see text][Formula: see text]g/ml) yielded the highest permeability ([Formula: see text]). Subsequently, three membrane protein inhibitors (verapamil, pantoprazole and probenecid) were used to explore the TFG absorption pathways. Data showed probenecid, a multidrug resistance protein (or MRP) inhibitor, effectively enhanced the TFG absorption ([Formula: see text]). Furthermore, by comparing commonly used natural absorption enhancers on TFG, it was observed that camphor was the most effective. In Situ single-pass intestinal perfusion experiment shows that TFG absorption is much higher in the small intestine than in the colon, and the TFG is absorbed mainly via an active transport pathway with MRP-mediated efflux mechanism. Camphor obviously enhanced the TFG absorption, and this could be an effective TFG formulation preparation method to increase clinical effectiveness after Genkwa Flos administration. Our study elucidated the TFG absorption mechanisms, and provided new information for its formulation preparation.

Antitumor and immunomodulatory activity of genkwanin on colorectal cancer in the APC(Min/+) mice

Colorectal cancer is the third most common malignant tumor with high morbidity and mortality. To evaluate the antitumor effect of genkwanin on colorectal cancer enhanced by western high-fat diet, we investigated the activity of genkwanin on HT-29 and SW-480 human colorectal cancer lines in vitro and on the APC(Min/+) mice in vivo. In a cell culture system, six different inflammatory cytokines obviously stimulated two cancer cells growth in a concentration-dependent manner, while genkwanin significantly inhibited HT-29 and SW-480 human colorectal cancer cells proliferation and inflammatory cytokine IL-8 secretion. In the APC(Min/+) mice, the body weights, spleen and thymus indexes and immunity cytokine secretions were significantly improved after oral administration 12.5 and 25mg/kg/day of genkwanin. Besides, the tumor multiplicity changes and inflammatory cytokine levels were markedly reduced in two genkwanin-treated groups. The dysplastic adenomatous changes were also obviously ameliorated in gut histopathology. Taken together, our results indicated that genkwanin had a better antitumor activity partly via enhancing host immunity and decreasing the inflammatory cytokine levels. Genkwanin may be an effective chemotherapeutic agent for the treatment of colorectal cancer.

STUDIES ON A SIMPLE AND EFFICIENT METHOD FOR LARGE-SCALE PREPARATION OF GENKWANIN FROM DAPHNE GENKWA SIEB. ET ZUCC. USING NORMAL-PHASE FLASH CHROMATOGRAPHY

Genkwanin, a flavonoid which has anti-oxidant and anti-tumor activities, was isolated and purified from flowers of Daphne genkwa Sieb. et Zucc. in a large-scale by normal-phase flash chromatography (NPFC). Dried flower buds were extracted with methanol at room temperature and concentrated. The residues were suspended in water and first extracted with petroleum ether, and then chloroform. Genkwanin was concentrated in the chloroform and insoluble fractions. Under the target-guidance of thin layer chromatography (TLC) as well as solubility, a solvent system composed of cyclohexane-acetone (22:3, v/v) was selected. At a flow rate of 30 mL/min,the insoluble and chloroform fractions were separated to yield 1.5 g and 1.35 g of genkwanin with high purities of 98.3% and 98.6% by HPLC analysis, respectively. The chemical structure of the compound was identified by ESI-MS and NMR. Results of the present study indicated that NPFC was a large preparative-scale, speedy and simple process separation technology and it was feasible to find the appropriate proportion of solvent system by transformation from TLC condition.