Meroterpenoids from Daphne genkwa shows promising in vitro antitumor activity via inhibiting PI3K/Akt/mTOR signaling pathway in A549 cells

Phytochemical investigation into the leaves and branches of Daphne genkwa afforded 25 meroterpenoids (1-16) including nine pairs of enantiomers (1a/1b-8a/8b and 12a/12b), among which 20 compounds have been reported in the present work for the first time. The structures with absolute configurations of the new molecules (excluding 10-13) were established via comprehensive spectroscopic analyses especially electronic circular dichroism (ECD) and Mosher's methods. A preliminary in vitro cell viability assay revealed remarkable cytotoxicities of selective compounds against A549 (lung), Hela (cervical), MDA-MB231 (breast) and MCF-7 (breast) cancer cells, and compound 8a showed the best inhibitory activity with IC50 values in the range of 3.12-4.67 μM toward the four cell lines. Subsequent in vitro antitumor evaluation of 8a disclosed that it could inhibit the proliferation and metastasis, as well as induce significant apoptosis and cycle arrest, of A549 cells. Further mechanistic investigations revealed that 8a could exert its antitumor activity via inhibiting the PI3K/Akt/mTOR signaling pathway.

Tigliane-and daphnane-type diterpenoids from the buds of Daphne genkwa with their cytotoxic activities

Two new tigliane- and daphnane-type diterpenoids, given the trivial names daphnegens A-B (1-2) were isolated from the buds of Daphne genkwa. Their structures were assigned on the basis of extensive spectroscopic. The absolute configurations of both compounds were determined by comparison of their calculated and experimental CD curves. In addition, compounds 1-2 were tested for their cytotoxic activities against MCF-7 and HepG-2 human cancer cell lines, and compound 2 showed remarkable cytotoxic activity against HepG-2 cell line with the IC50 value of 11.5 μM.

Identification of Daphne genkwa and Its Vinegar-Processed Products by Ultraperformance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry and Chemometrics

Crude herbs of Daphne genkwa (CHDG) are often used in traditional Chinese medicine to treat scabies baldness, carbuncles, and chilblain owing to their significant purgation and curative effects. The most common technique for processing DG involves the use of vinegar to reduce the toxicity of CHDG and enhance its clinical efficacy. Vinegar-processed DG (VPDG) is used as an internal medicine to treat chest and abdominal water accumulation, phlegm accumulation, asthma, and constipation, among other diseases. In this study, the changes in the chemical composition of CHDG after vinegar processing and the inner components of the changed curative effects were elucidated using optimized ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Untargeted metabolomics, based on multivariate statistical analyses, was also used to profile differences between CHDG and VPDG. Eight marker compounds were identified using orthogonal partial least-squares discrimination analysis, which indicated significant differences between CHDG and VPDG. The concentrations of apigenin-7-O-β-d-methylglucuronate and hydroxygenkwanin were considerably higher in VPDG than those in CHDG, whereas the amounts of caffeic acid, quercetin, tiliroside, naringenin, genkwanines O, and orthobenzoate 2 were significantly lower. The obtained results can indicate the transformation mechanisms of certain changed compounds. To the best of our knowledge, this study is the first to employ mass spectrometry to detect the marker components of CHDG and VPDG.

Daphne genkwa flower extract promotes the neuroprotective effects of microglia

BACKGROUND

Microglia are innate immune cells in the central nervous system that play a crucial role in neuroprotection by releasing neurotrophic factors, removing pathogens through phagocytosis, and regulating brain homeostasis. The constituents extracted from the roots and stems of the Daphne genkwa plant have shown neuroprotective effects in an animal model of Parkinson's disease. However, the effect of Daphne genkwa plant extract on microglia has yet to be demonstrated.

PURPOSE

To study the anti-inflammatory and neuroprotective effects of Daphne genkwa flower extract (GFE) in microglia and explore the underlying mechanisms.

METHODS

In-vitro mRNA expression levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), inducible nitric oxide synthase, Arginase1, and brain derived neurotropic factor (BDNF) were analyzed by reverse transcription polymerase chain reaction in microglia cells. Nitric oxide (NO) and TNF-α protein were respectively analyzed by Griess reagent and Enzyme Linked Immunosorbent Assay. Immunoreactivity of Iba-1, Neu-N, and BDNF in mouse brain were analyzed by immunofluorescence staining. Phagocytosis capacity of microglia was examined using fluorescent zymosan-red particles.

RESULTS

GFE significantly inhibited lipopolysaccharide (LPS)-induced neuroinflammation and promoted neuroprotection both in vitro and in vivo. First, GFE inhibited the LPS-induced inflammatory factors NO, iNOS, and TNF-α in microglial cell lines and primary glial cells, thus demonstrating anti-inflammatory effects. Arginase1 and BDNF mRNA levels were increased in primary glial cells treated with GFE. Phagocytosis was also increased in microglia treated with GFE, suggesting a neuroprotective effect of GFE. In vivo, neuroprotective and anti-neuroinflammatory effects of GFE were also found in the mouse brain, as oral administration of GFE significantly inhibited LPS-induced neuronal loss and inflammatory activation of microglia.

CONCLUSION

GFE has anti-inflammatory effects and promotes microglial neuroprotective effects. GFE inhibited the pro-inflammatory mediators and enhanced neuroprotective microglia activity by increasing BDNF expression and phagocytosis. These novel findings of the GFE effect on microglia show an innovative approach that can potentially promote neuroprotection for the prevention of neurodegenerative diseases.

Guided isolation of daphnane-type diterpenes from Daphne genkwa by molecular network strategies

A molecular networking-guided study on the Daphne genkwa Sieb. et Zucc led to the isolation of twelve daphnane-type diterpenoids including four undescribed compounds, yuanhuakines A-D. Their structures were elucidated by spectroscopic analyses, ECD calculations, and single-crystal X-ray diffraction analysis. All isolates were evaluated for their inhibitory activity against the A549, Hep3B, and MCF-7 cell lines. The majority of compounds inhibited A549 cells with IC₅₀ values ranging from 7.77 to 20.56 μM, and their structure-activity relationship is preliminarily discussed. Five of these compounds were selected for further experiments, and they appear to inhibit A549 cell lines by inducing apoptosis.

Effects of the total flavonoid extracts and the monomers of Daphne genkwa on CYP2C8 activity

1. This study aimed to assess the effects of total flavonoid extracts (TFDG) and the monomers of Daphne genkwa on the CYP2C8 activity in vitro and in vivo.2. The 50% inhibitory concentration (IC₅₀) values were used to determine the inhibitory effect of TFDG and its four monomers for the CYP2C8 activity by recombinant human CYP2C8 (RHCYP2C8) yeast microsome system in vitro, and the volume per dose index (VDI) was predicted the potential inhibition in vivo. The effects of multiple-dose administration of TFDG on the pharmacokinetic parameters of rosiglitazone in rats were evaluated.3. The IC₅₀ values of apigenin, luteolin, hydroxy-genkwanin, genkwanin, and TFDG were 7.27μmol/L, 11.9μmol/L, 28.1μmol/L, 127μmol/L, and 13.4μg/mL, respectively. The VDI values of apigenin and TFDG were 2.15L and 6.60L. In vivo study, compared with the control group, the elimination phase half-life and mean residence time in the TFDG treatment group were significantly increased by 96.9% and 106.8% (p < 0.05), respectively.4. Apigenin showed a moderate inhibitory effect on the CYP2C8 activity in vitro, while the other three monomers were weak inhibitors. TFDG had a strong inhibitory effect on CYP2C8 in vitro and in vivo, and also inhibited the metabolism of rosiglitazone in rats.

Comprehensive evaluation on anti-inflammatory and anti-angiogenic activities in vitro of fourteen flavonoids from Daphne Genkwa based on the combination of efficacy coefficient method and principal component analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Genkwa flos, as a traditional herb, is the dried flower buds of Daphne genkwa Sieb.et Zucc. It is used in traditional medicine for the treatment of cough, sore throats, edema.

AIM OF THE STUDY

The study aimed to explore a new mathematical method for multivariate evaluation, investigate the anti-inflammatory and anti-angiogenic activities of flavonoids in Daphne Genkwa under ex vivo conditions.

MATERIALS AND METHODS

The flavonoids monomers in Daphne Genkwa were separated by preparative liquid chromatography and identified by HPLC-ESI-ITMS. An in vitro inflammatory model of macrophage RAW264.7 induced by LPS and an angiogenesis model of human umbilical vein endothelial cells induced by TNF-α were established. Flavonoids were extracted and prepared for intervention to detect the amount of secretion after drug intervention to reflect the anti-inflammatory and anti-angiogenic activities of each component. In addition, a new mathematical method, which combined principal component analysis and efficacy coefficient method, was adopted in pharmacodynamic evaluation.

RESULTS

Fourteen flavonoids monomers were separated by preparative liquid chromatography and identified by HPLC-ESI-ITMS including H1 (hydroxygenkwanin-5-O-β-D-glucoside), H2 (apigenin-7-O-β-D-glucoside), H3 (kaempferol-3-O-β-D-glucoside), H4 (hydroxygenkwanin-5-O-β-D-primeveroside), H5 (apigenin-5-O-β-D-primeveroside), H6 (apigenin-7-O-β-D-glucuronide), H7 (luteolin-5-O-β-D-glucopyranoside), H8 (genkwain-5-O-β-D- glucoside), H9 (luteolin), H10 (Daphnodorin G), H11 (tiliroside), H12 (apigenin), H13 (3'- hydroxygenkwain) and H14 (genkwanin). We found that most of flavonoids down-regulated VCAM and MMP-3, while H1, H8, H9, H14 reduced VEGF and ICAM was only decreased by H14.

CONCLUSION

Genkwanin may be the most active anti-rheumatoid arthritis flavonoids in Daphne genkwa. Meanwhile, the new mathematical method used in the study provided a new direction for solving the problem of multi-index pharmacodynamic evaluation.

Licorice-Yuanhua Herbal Pair Induces Ileum Injuries Through Weakening Epithelial and Mucous Barrier Functions: Saponins, Flavonoids, and Di-Terpenes All Involved

In traditional Chinese Medicine (TCM), the licorice-yuanhua herbal pair is one of the most representative incompatible herbal pairs recorded in the “eighteen incompatible herbal pairs” theory. Previous studies of our research group have demonstrated several gut-related side-effects induced by the licorice-yuanhua herbal pair. In this study, we investigated whether and why this incompatible herbal pair could induce gut tissue damage. After licorice-yuanhua treatment, the duodenum, ileum, and colon and serum biomarkers of mice were examined by pathological staining, Western blot, and ELISA assays. The IEC-6 cells and LS174T cells were treated with licorice saponins, yuanhua flavonoids, and di-terpenes; iTRAQ-labeled proteomic technology was then used to explore their synergistic effects on mucosa cells, followed by verification of ZO-1 and MUC-2 protein expressions. The results showed that the licorice-yuanhua herbal pair induced ileum tissue injuries, including epithelial integrity loss, inflammation, and edema. These injuries were verified to be related to epithelial and mucous barrier weakening, such as downregulated ileum ZO-1 and MUC-2 protein expressions. Proteomic analysis also suggested that glycyrrhizic acid and genkwanin synergistically influence tight junction pathways in LS174T cells. Furthermore, licorice saponins, yuanhua flavonoids, and di-terpenes dose/structure-dependently downregulate ZO-1 and MUC-2 protein expressions in mucosa cells. Our study provides different insights into the incompatibility mechanisms and material basis of the licorice-yuanhua herbal pair, especially that besides toxic di-terpenes, licorice saponins and yuanhua flavonoids, which are commonly known to be non-toxic compounds, can also take part in the gut damage induced by the licorice-yuanhua herbal pair.

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.

Hydroxygenkwanin Suppresses Non-Small Cell Lung Cancer Progression by Enhancing EGFR Degradation

Epidermal growth factor receptor (EGFR) is frequently overexpressed and mutated in non-small cell lung cancer (NSCLC), which is the major type of lung cancer. The EGFR tyrosine kinase inhibitors (TKIs) are the approved treatment for patients harboring activating mutations in the EGFR kinase. However, most of the patients treated with EGFR-TKIs developed resistance. Therefore, the development of compounds exhibiting unique antitumor activities might help to improve the management of NSCLC patients. The total flavonoids from Daphne genkwa Sieb. et Zucc. have been shown to contain antitumor activity. Here, we have isolated a novel flavonoid hydroxygenkwanin (HGK) that displays selective cytotoxic effects on all of the NSCLC cells tested. In this study, we employed NSCLC cells harboring EGFR mutations and xenograft mouse model to examine the antitumor activity of HGK on TKI-resistant NSCLC cells. The results showed that HGK suppressed cancer cell viability both in vitro and in vivo. Whole-transcriptome analysis suggests that EGFR is a potential upstream regulator that is involved in the gene expression changes affected by HGK. In support of this analysis, we presented evidence that HGK reduced the level of EGFR and inhibited several EGFR-downstream signalings. These results suggest that the antitumor activity of HGK against TKI-resistant NSCLC cells acts by enhancing the degradation of EGFR.

A new flavanol from the roots of Daphne genkwa

The phytochemical investigation of the roots of Daphne genkwa yielded six secondary metabolites, including a new flavanol derivative, (2R, 3S)-5,7,4'-trihydroxy-8-methoxycarbonylflavanol (1), and five known compounds (2-6). The molecular structures of the isolated constituents were elucidated on the basis of extensive spectroscopic analysis, including UV, IR, NMR, and MS, and comparison with literature data. Furthermore, the cytotoxic activity of 1 and 2 against A549, HL-60, SMMC-7721, MCF-7, and SW480 cell lines was also described.

Health risk of Licorice-Yuanhua combination through induction of colonic H2S metabolism

ETHNOPHARMACOLOGICAL RELEVANCE

Licorice and Yuanhua are both famous herbs in Traditional Chinese Medicine (TCM), and their combination is used by some TCM doctors to treat renal and gastrointestinal diseases as well as tumors. On the other hand, the compatibility theory of TCM warns that toxic effects might be triggered by Licorice-Yuanhua combination. The usability of Licorice-Yuanhua combination has long been controversial due to lack of evidence and mechanism illustration. Colonic hydrogen sulfide (H₂S) metabolism imbalance is closely related with colonic inflammation, tumor promotion and many other diseases.

AIM OF THE STUDY

This study was carried out to investigate if licorice-Yuanhua combination could induce potential toxic effects in the aspect of colonic H₂S metabolism.

MATERIALS AND METHODS

Normal mice were treated with high or low doses of Licorice, Yuanhua and Licorice-Yuanhua combination. Fecal H₂S concentration was measured by colorimetric method, colon sulfomucin production was compared through tissue staining, fecal microbiota and microbial metagenomes were analyzed by 16S rDNA sequencing and data mining.

RESULTS

Data shows that although licorice cannot change colonic H₂S concentration, it can exacerbate Yuanhua induced H₂S rising. Licorice or Yuanhua increases colon sulfomucin production, and their combination further enhances this effect. 16S rDNA sequencing analysis revealed that licorice or Yuanhua has little influence on gut microbiota, however, licorice-Yuanhua combination can impact gut microbiota structural balance and increase the abundance of Desulfovibrio genus and other related genera. Moreover, the combination extensively changes microbial metagenomes, influencing 1172 genes that cannot be changed by individual licorice or Yuanhua. By searching in KEGG database, ten genes are annotated with H₂S producing gene, and these genes are remarkably increased by licorice-Yuanhua combination, more significantly than licorice or Yuanhua.

CONCLUSIONS

This study provides evidences and mechanisms for licorice induced risks, which is related with colonic H₂S metabolism disturbance, gut microbiota and microbial metagenomes. More risk assessment should be evaluated when licorice was used in combination with foods, herbs or drugs. The study provides an example where healthy risks can be induced by combination of food additive, herbs or drugs, through regulating gut microbiota and its metagenomes.

Neogenkwanine I from the flower buds of Daphne genkwa with its stereostructure confirmation using quantum calculation profiles and antitumor evaluation

Neogenkwanine I (1), a new daphnane-type diterpene with 4,7-ether group, along with four known ones (2-5), were isolated from Daphne genkwa. The structure including absolute configurations of 1 was established on the basis of NMR, ¹³C-NMR and ECD calculations and CD exciton chirality analysis. ¹³C-NMR and ECD calculations of daphnane-type diterpenes were reported here for the first time. All of the diterpenes were screened for their cytotoxic activities against MCF-7 and Hep3B cell lines. The cytotoxicity structure- activity relationship of compounds was illustrated with the absence of ortho-ester group of daphnane-type diterpenes.

Daphnane and Phorbol Diterpenes, Anti-neuroinflammatory Compounds with Nurr1 Activation from the Roots and Stems of Daphne genkwa

The methanol extract of the roots and stems of Daphne genkwa and its constituents yuanhuacin (1) and genkwanine N were previously reported to have Nurr1 activating effects and neuroprotective effects in an animal model of Parkinson's disease (PD). In this study, four more daphnane-type diterpenes (acutilonine F (2), wikstroemia factor M₁ (3), yuanhuadine (5), and yuanhuatine (6)) and two phorbol-type diterpenes (prostratin Q (4) and 12-O-n-deca-2,4,6-trienoyl-phorbol-(13)-acetate (7)) were isolated as Nurr1 activating compounds from the D. genkwa extract. Consistent with their higher Nurr1 activating activity, compounds 1, 4, 5, and 7 exhibited higher inhibitory activity on lipopolysaccharide (LPS)-induced nitric oxide (NO) production in murine microglial BV-2 cells with an IC₅₀ (µM) of 1-2, which was 15-30 times more potent than that of minocycline (29.9 µM), a well-known anti-neuroinflammatory agent. Additionally, these diterpenes reduced expression and transcription of LPS-induced pro-inflammatory cytokines in BV-2 cells. Thus, the daphnane-type and phorbol-type diterpenes had anti-neuroinflammatory activity with Nurr1 activation and could be responsible for the anti-PD effect of the roots and stems of D. genkwa.

[Vinegar processing attenuates toxicity on IEC-6 cells caused by chloroform extraction of Daphne genkwa]

To screen the toxic polar fractions of Daphne genkwa, compare the toxicity of D. genkwa on crypts epithelial cells IEC-6 before and after vinegar processing, and preliminarily investigate the mechanism of D. genkwa vinegar processing on toxicity reducing. The proliferation of IEC-6 cells was observed by MTT. The levels of superoxide dismutase (SOD), malondialdehyde (MDA), glutathione (GSH), lactate dehydrogenase (LDH), as well as the enzyme activity of Na⁺-K⁺-ATPase and Ca²⁺-Mg²⁺-ATPase were determined in IEC-6 cells to evaluate the oxidative damages degree of IEC-6 cells. The apoptosis and cell cycle were analyzed by Flow Cytometry. The results showed that the dichloromethane extraction was the toxic polar fraction of D. genkwa, and after vinegar processing, the toxicity of dichloromethane fraction was significantly reduced (P<0.01). As compared with the blank control group, the dichloromethane fraction of D. genkwa can obviously decrease the levels of SOD, Na⁺-K⁺-ATPase, Ca²⁺-Mg²⁺-ATPase (P<0.01) and content of GSH, but increase the level of LDH and MDA in cell supernatant (P<0.01). Besides, it obviously increased the early and late apoptotic rate of IEC-6 cells, obviously decreased the proportion of G₁stage cells, increased the ratio of S stage cells and M stage cells (P<0.01). After vinegar processing, as compared with D. genkwa groups of various doses, it can significantly increase the levels of SOD, Na⁺-K⁺-ATPase, Ca²⁺-Mg²⁺-ATPase (P<0.01) and content of GSH, decrease the level of LDH, MDA(P<0.01), significantly decrease the early and late apoptosis rate of IEC-6 cells (P<0.01), increase the proportion of G₁stage cells, and decrease the ratio of S stage cells and M stage cells (P<0.01). Vinegar processing can reduce the toxicity of dichloromethane fraction of D. genkwa, and its mechanism may be associated with improving the activity of antioxidant enzymes and permeability in IEC-6 cells, and decreasing the oxidative damage.

Simultaneous determination of three flavonoids and one coumarin by LC-MS/MS: Application to a comparative pharmacokinetic study in normal and arthritic rats after oral administration of Daphne genkwa extract

A selective and sensitive liquid chromatography-tandem mass spectrometry method was developed and validated for investigating the pharmacokinetics of umbelliferone, apigenin, genkwanin and hydroxygenkwanin after oral administration of Daphne genkwa extract. Plasma samples were treated by protein precipitation with acetonitrile. Analytes were detected by triple-quadrupole MS/MS with an ESI source in negative selection reaction monitoring mode. The transitions of m/z 161 → 133 for umbelliferone, m/z 269 → 117 for apigenin, m/z 283 → 268 for genkwanin and m/z 299 → 284 for hydroxygenkwanin were confirmed for quantification. Chromatographic separation was conducted using an Eclipse XDB-C₁₈ column, and the applied isocratic elution program allowed for simultaneous determination of the four analytes for a total run time of 2.5 min. The linearity was validated over the plasma concentration ranges of 1.421-1421 ng/mL for umbelliferone, 0.845-845 ng/mL for apigenin, 1.025-1025 ng/mL for genkwanin and 0.845-845 ng/mL for hydroxygenkwanin. The extraction recovery rate was >82.7% for each analyte. No apparent matrix effect was observed during the bioanalysis. After full validation, the proposed method was successfully applied to compare the pharmacokinetics of these analytes between normal and arthritic rats.

[Morphological and microscopical identification of Genkwa Ramulus and its adulterants]

The purpose of this article is to identify Daphne genkwa and its adulterants, Wikstroemia chamaedaphne, according to the morphological and microstructure characteristics of their stem and foliage. The root of D.genkwa was studied simultaneously. The results indicated that the crude drug and processed pieces of Genkwa Ramulus were mainly composed of stems and branches where obvious opposite petiole scars and branch marks were able to be seen on their nodes. Otherwise, foliage or peduncles generally couldn't be found. Moreover, the fine silver flocculent fibers could be observed in the bark of fracture surface. The adulterants were the plant segments which were composed of stems, foliage and peduncles with spikelet-pedicel scars. There existed microstructures differences between Genkwa Ramulus and its adulterants. In the former, single thick lignified phloem fibers were interspersed in the stem phloem of the transverse section with very thick wall and unicellular non-glandular hairs could be observed on the lower epidermis of foliage. Nevertheless, in the latter, there was no thick lignified phloem fibers in cross section of stem phloem, the outer wall of epidermal cells of foliage hadthick cuticles and no non-glandular hairs in lower epidermis of foliage. The results can be used for the identification and the quality standard of the crude drug and processed pieces of D.genkwa.The characteristics of the microstructures and the transverse section can be used to identify the radix D.genkwa.

Genkwalathins A and B, new lathyrane-type diterpenes from Daphne genkwa

Screening for new natural anti-neuroinflammatory compounds was performed with the traditional folk medicine Genkwa Flos, which potently inhibited nitric oxide (NO) production by LPS-activated microglial BV-2 cells. Two new lathyrane-type diterpenes, genkwalathins A (1) and B (2), and 14 known daphnane-type diterpenes (3-16) were isolated. The lathyrane-type diterpenes were isolated for the first time from the Thymelaeaceae family in this study. Compounds 1 and 2 moderately inhibited LPS-induced NO production in BV-2 cells without affecting cell viability, while six daphnane-type diterpenes (3, 4, 6, 7, 9 and 10) potently reduced NO production with IC₅₀ values less than 1 μM, although they did display weak cytotoxicity. A structure-activity relationship study on the daphnane-type diterpenes indicated that the stereochemistry at C-19, the benzoate group at C-20, and the epoxide moiety could be important for their anti-neuroinflammatory effects.

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.

Relationship between the UPLC-Q-TOF-MS fingerprinted constituents from Daphne genkwa and their anti-inflammatory, anti-oxidant activities

Daphne genkwa Sieb.et Zucc. is a well-known medicinal plant. This study was designed to apply the ultra-high performance liquid chromatography system to establish a quality control method for D. genkwa. Data revealed that there were 15 common peaks in 10 batches of D. genkwa Sieb. Et Zucc. (Thymelaeaceae) from different provinces of China. On this basis, the fingerprint chromatogram was established to provide references for quality control. Afterwards, the chemical constitutions of these common peaks were analyzed using the UPLC-Q-TOF-MS system and nine of them were identified. In addition, LPS-stimulated RAW264.7 murine macrophages and DPPH assay were used to study the anti-inflammatory and anti-oxidation effects of D. genkwa. Then the fingerprint-efficacy relationships between UPLC fingerprints and pharmacodynamic data were studied with canonical correlation analysis. Analysis results indicated that the anti-inflammatory and anti-oxidation effects differed among the 10 D. genkwa samples owing to their inherent differences of chemical compositions. Taken together, this research established a fingerprint-efficacy relationship model of D. genkwa plant by combining the UPLC analytic technique and pharmacological research, which provided references for the detection of the principal components of traditional Chinese medicine on bioactivity.

Root extractive from Daphne genkwa benefits in wound healing of anal fistula through up-regulation of collagen genes in human skin fibroblasts

Wound healing is the main problem in the therapy of anal fistula (AF). Daphne genkwa root has been traditionally used as an agent to soak sutures in operation of AF patients, but its function in wound healing remains largely unclear. The aim of the present study was to illuminate mechanisms of D. genkwa root treatment on AF. In the present study, 60 AF patients after surgery were randomly divided into two groups, external applied with or without the D. genkwa extractive. Wound healing times were compared and granulation tissues were collected. In vitro, we constructed damaged human skin fibroblasts (HSFs) with the treatment of TNF-α (10 μg/ml). Cell Count Kit-8 (CCK-8) and flow cytometry analysis were used to determine the effects of D. genkwa root extractive on cell viability, cell cycle and apoptosis of damaged HSFs. Furthermore, protein levels of TGF-β, COL1A1, COL3A1, Timp-1, matrix metalloproteinase (MMP)-3 (MMP-3) and MEK/ERK signalling pathways were investigated both in vivo and in vitro Results showed that D. genkwa root extractive greatly shortens the wound healing time in AF patients. In granulation tissues and HSFs, treatment with the extractive significantly elevated the expressions of COL1A1, COL3A1, Timp-1, c-fos and Cyclin D1, while reduced the expression of MMP-3 Further detection presented that MEK/ERK signalling was activated after the stimulation of extractive in HSFs. Our study demonstrated that extractive from D. genkwa root could effectively improve wound healing in patients with AF via the up-regulation of fibroblast proliferation and expressions of COL1A1 and COL3A1.

Antitumor Activity of Total Flavonoids from Daphne genkwa in Colorectal Cancer

Daphne genkwa Sieb.et Zucc. is a well-known medicinal plant. This study was designed to investigate the anticancer effects of total flavonoids in D. genkwa (TFDG) in vitro and in vivo. HT-29 and SW-480 human colorectal cancer cells were cultured to investigate the anticancer activity of TFDG. In addition, the Apc(Min/+) mouse model was applied in the in vivo experiment. Results of the cell experiment revealed that TFDG possessed significant inhibitory effects on HT-29 and SW-480 human colorectal cancer cells (both p < 0.01). Furthermore, our in vivo data showed that after treatment with TFDG, there was a significant increase in life span (both p < 0.01) and tumor numbers were reduced in the colon (both p < 0.01), which was supported by the data of tumor distribution, body weight changes and organ index. Our results also indicated that expressions of interleukin (IL)-1α, IL-1β, IL-6, granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor in gut tissue were downregulated by treatments of TFDG, and immunity cytokine secretions in the serum were regulated after oral administration of TFDG. Taken together, these findings suggested that TFDG has a potential clinical utility in colorectal cancer therapeutics, and TFDG's action is likely linked to its ability to regulate immune function and inhibit the production of inflammatory cytokines.

Anti-herpes Activity of Vinegar-processed Daphne genkwa Flos Via Enhancement of Natural Killer Cell Activity

Herpes simplex virus (HSV) is a common causative agent of genital ulceration and can lead to subsequent neurological disease in some cases. Here, using a genital infection model, we tested the efficacy of vinegar-processed flos of Daphne genkwa (vp-genkwa) to modulate vaginal inflammation caused by HSV-1 infection. Our data revealed that treatment with optimal doses of vp-genkwa after, but not before, HSV-1 infection provided enhanced resistance against HSV-1 infection, as corroborated by reduced mortality and clinical signs. Consistent with these results, treatment with vp-genkwa after HSV-1 infection reduced viral replication in the vaginal tract. Furthermore, somewhat intriguingly, treatment of vp-genkwa after HSV-1 infection increased the frequency and absolute number of CD3^-NK1.1⁺NKp46⁺ natural killer (NK) cells producing interferon (IFN)-γ and granyzme B, which indicates that vp-genkwa treatment induces the activation of NK cells. Supportively, secreted IFN-γ was detected at an increased level in vaginal lavages of mice treated with vp-genkwa after HSV-1 infection. These results indicate that enhanced resistance to HSV-1 infection by treatment with vp-genkwa is associated with NK cell activation. Therefore, our data provide a valuable insight into the use of vp-genkwa to control clinical severity in HSV infection through NK cell activation.

Functional restoration of exhausted CD4(+) and CD8(+) T cells in chronic viral infection by vinegar-processed flos of Daphne genkwa. Comp Immunol Microbiol Infect Dis. 2015;39:25-37. [PMID: 25744061 DOI: 10.1016/j.cimid.2015.02.001]

T-cell exhaustion has become an important issue in chronic infection because exhausted antigen-specific T cells show impaired abilities to eradicate persistently infected pathogens and produce effector cytokines, such as IFN-γ and TNF-α. Thus, strategies to either restore endogenous exhausted T cell responses or provide functional T cells are needed for therapeutics of chronic infection. Despite promising developments using antibodies and cell immunotherapy, there have been no reported attempts to restore exhausted T cells using treatment with materials derived from natural resources. Here, using a mouse model of chronic infection with lymphocytic choriomeningitis virus (LCMV), we found that vinegar-processed flowers (flos) of Daphne genkwa (vp-genkwa), which was composed mainly of four index components, restored exhausted CD4(+) and CD8(+) T cells significantly, as corroborated by evidence that vp-genkwa treatment enhanced functional LCMV-specific CD4(+) and CD8(+) T cells, both quantitatively and qualitatively. Furthermore, pretreatment with vp-genkwa prevented the generation of exhausted LCMV-specific CD8(+) T cells. Such restorations of exhausted LCMV-specific CD4(+) and CD8(+) T cells by vp-genkwa were closely associated with reduced viral burden in sera and tissues. More interestingly, vp-genkwa treatment induced down-regulation of negative molecules, such as PD-1 and Tim-3, in exhausted CD4(+) and CD8(+) T cells with more apparent down-regulation of Tim-3, suggesting that Tim-3 molecule may be a major target in restoring exhausted T cell responses. Collectively, these results provide valuable new insights into the use of vp-genkwa to develop a therapeutic strategy for chronic human diseases, such as hepatitis B and C virus, human immunodeficiency virus, and cancers.

Anti-rheumatoid arthritic activity of flavonoids from Daphne genkwa

The aim of the study was to investigate the anti-rheumatoid arthritic activity of four flavonoids from Daphne genkwa (FFD) in vivo and in vitro. Flavonoids of D. genkwa were extracted by refluxing with ethanol and purified by polyamide resin. An in vivo carrageenan-induced paw edema model, tampon-granuloma model and Freund's complete adjuvant (FCA)-induced arthritis mouse model were used to evaluate the anti-rheumatoid arthritic activities of FFD. Moreover, nitric oxide (NO) release and neutral red uptake (NRU) in lipopolysaccharide (LPS)-induced murine macrophage RAW264.7 cells were used to evaluate the anti-inflammatory effect in vitro. In addition, antioxidant effect of FFD was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. A high dose of FFD significantly reduced the degree of acute inflammatory paw edema in mice as a response to carrageenan administration (p<0.01). FFD displayed a dose-dependent inhibition of granuloma formation in mice (p<0.05). FFD also inhibited chronic inflammation in adjuvant-induced arthritis rats when administered orally at the dose of 50mg/kg/day (p<0.001). In addition, FFD suppressed the production of NO and exhibited immunoregulatory function in LPS-activated RAW264.7 cells in a dose-related manner. Simultaneously, FFD revealed conspicuous antioxidant activity with IC50 values of 18.20μg/ml. FFD possesses significant anti-inflammatory and antioxidant activity, which could be a potential therapeutic agent for chronic inflammatory disorders such as rheumatoid arthritis.