Hydroxytyrosol is an important fine chemical and is widely used in food and medicine as a natural antioxidant. Production of hydroxytyrosol through synthetic biology is of important significance. Here we cloned and functionally characterized a hydroxylase encoding gene HpaBC from Escherichia coli BL21, and both subunits of this enzyme can be successfully expressed to convert the tyrosol into hydroxytyrosol. A HpaBC gene integration expression cassette under the tac promoter was constructed, and integrated into the genome of a tyrosol hyper-producing E. coli YMG5A*R using CRISPR-Cas9 technology. Meanwhile, the pathway for production of acetic acid was deleted, resulting in a recombinant strain YMGRD1H1. Shake flask fermentation showed that strain YMGRD1H1 can directly use glucose to produce hydroxytyrosol, reaching a titer of 1.81 g/L, and nearly no by-products were detected. A titer of 2.95 g/L was achieved in a fed-batch fermentation conducted in a 5 L fermenter, which is the highest titer for the de novo synthesis of hydroxytyrosol from glucose reported to date. Production of hydroxytyrosol by engineered E. coli lays a foundation for further construction of hydroxytyrosol cell factories with industrial application potential, adding another example for microbial manufacturing of aromatic compounds.
Escherichia coli/genetics* ; Fermentation ; Glucose ; Metabolic Engineering ; Phenylethyl Alcohol/analogs & derivatives*

Periodontal disease is associated with chronic oxidative stress and inflammation. Caffeic acid phenethyl ester (CAPE), which is a potent inducer of heme oxygenase 1 (HO1), is a central active component of propolis, and the application of propolis improves periodontal status in diabetic patients. Here, primary murine macrophages were exposed to CAPE. Target gene expression was assessed by whole-genome microarray, RT-PCR and Western blotting. The antioxidative and anti-inflammatory activities of CAPE were examined by exposure of the cells to hydrogen peroxide, saliva and periodontal pathogens. The involvement of HO1 was investigated with the HO1 inhibitor tin protoporphyrin (SnPP) and knockout mice for Nrf2, which is a transcription factor for detoxifying enzymes. CAPE increased HO1 and other heat shock proteins in murine macrophages. A p38 MAPK inhibitor and Nrf2 knockout attenuated CAPE-induced HO1 expression in macrophages. CAPE exerted strong antioxidative activity. Additionally, CAPE reduced the inflammatory response to saliva and periodontal pathogens. Blocking HO1 decreased the antioxidative activity and attenuated the anti-inflammatory activity of CAPE. In conclusion, CAPE exerted its antioxidative effects through the Nrf2-mediated HO1 pathway and its anti-inflammatory effects through NF-κB inhibition. However, preclinical models evaluating the use of CAPE in periodontal inflammation are necessary in future studies.
Animals ; Caffeic Acids ; pharmacology ; Heme Oxygenase-1 ; genetics ; metabolism ; Humans ; Inflammation ; drug therapy ; Mice ; NF-kappa B ; antagonists & inhibitors ; genetics ; metabolism ; Oxidative Stress ; drug effects ; Phenylethyl Alcohol ; analogs & derivatives ; pharmacology

PURPOSE: In the gastric mucosa of Helicobacter pylori (H. pylori)-infected patients with gastritis or adenocarcinoma, proliferation of gastric epithelial cells is increased. Hyperproliferation is related to induction of oncogenes, such as β-catenin and c-myc. Even though transcription factors NF-κB and AP-1 are activated in H. pylori-infected cells, whether NF-κB or AP-1 regulates the expression of β-catenein or c-myc in H. pylori-infected cells has not been clarified. The present study was undertaken to investigate whether H. pylori-induced activation of NF-κB and AP-1 mediates the expression of oncogenes and hyperproliferation of gastric epithelial cells. MATERIALS AND METHODS: Gastric epithelial AGS cells were transiently transfected with mutant genes for IκBα (MAD3) and c-Jun (TAM67) or treated with a specific NF-κB inhibitor caffeic acid phenethyl ester (CAPE) or a selective AP-1 inhibitor SR-11302 to suppress activation of NF-κB or AP-1, respecively. As reference cells, the control vector pcDNA was transfected to the cells. Wild-type cells or transfected cells were cultured with or without H. pylori. RESULTS: H. pylori induced activation of NF-κB and AP-1, cell proliferation, and expression of oncogenes (β-catenein, c-myc) in AGS cells, which was inhibited by transfection of MAD3 and TAM67. Wild-type cells and the cells transfected with pcDNA showed similar activities of NF-κB and AP-1, proliferation, and oncogene expression regardless of treatment with H. pylori. Both CAPE and SR-11302 inhibited cell proliferation and expression of oncogenes in H. pylori-infected cells. CONCLUSION: H. pylori-induced activation of NF-κB and AP-1 regulates transcription of oncogenes and mediates hyperproliferation in gastric epithelial cells.
Blotting, Western ; Caffeic Acids ; Cell Line, Tumor ; Cell Proliferation ; DNA, Bacterial/analysis/genetics ; DNA-Binding Proteins/*metabolism ; Epithelial Cells/*metabolism ; Gastric Mucosa/*metabolism/pathology ; Gastritis/pathology ; Gene Expression Regulation, Bacterial ; Helicobacter Infections/metabolism/pathology/physiopathology ; Helicobacter pylori/pathogenicity/physiology ; Humans ; NF-kappa B/antagonists & inhibitors/*biosynthesis/metabolism ; Peptide Fragments ; Phenylethyl Alcohol/analogs & derivatives ; Proto-Oncogene Proteins c-jun ; Repressor Proteins ; Transcription Factor AP-1/*biosynthesis ; Transcription Factors/*metabolism ; beta Catenin/*metabolism

Tyrosol, crenulatin and salidroside are the main active constituents of Rhodiola crenulata, with extensive pharmacological activities. In the study, grams of high purity tyrosol, crenulatin and salidroside were simultaneously separated from R. crenulata by the first time. Firstly, R. crenulata was extracted by 70% alcohol. Then, with the yields of three compounds as the index, the macroporous resin was optimized. At last, grams of high purity tyrosol, crenulatin and salidroside were isolated by D-101 macroporousresin, purified by column chromatography. Detected by HPLC, the purity of three compounds were higher than 98%. This method has the advantages of simple process and operation, less dosage of organic solvent, highly yield and reproducibility, suitable for the simultaneously preparation of tyrosol, crenulatin and salidroside.
Chemical Fractionation ; methods ; Chemistry, Pharmaceutical ; Chromatography, High Pressure Liquid ; Coumarins ; analysis ; isolation & purification ; Drugs, Chinese Herbal ; analysis ; isolation & purification ; Glucosides ; analysis ; isolation & purification ; Phenols ; analysis ; isolation & purification ; Phenylethyl Alcohol ; analogs & derivatives ; analysis ; isolation & purification ; Rhodiola ; chemistry

OBJECTIVETo investigate the effect of andrographolide (AG) on quroum sensing (QS) and relevant virulence genes of Candida albicans.

METHODGas-chromatography-mass spectrometry (GC-MS) was applied to detect the changes in the content of farnesol and tyrosol in C. albicans intervened by AG. The real-time quantitative PCR (qRT-PCR) was adopted to inspect the expressions of relevant virulence genes such as CHK1, PBS2 and HOG1 regulated by QS.

RESULTAt 2 h after the growth of C. albican, the farnesol and tyrosol secretions reduced, without notable change after intervention with AG. The secretions were highest at 12 h and decreased at 24 h. After the intervention with different concentrations of AG, the farnesol content reduces, whereas tyrosol increased, indicating a dose-dependence, particularly with 1 000 mg x L(-1) AG. qRT-PCR revealed that 1 000 mg x L(-1) AG could down-regulate CHK1 by 2.375, 3.330 and 4.043 times and PBS2 by 2.010, 4.210 and 4.760 times, with no significant change in HOG1.

CONCLUSIONAG could inhibit the farnesol secretion, promote the tyrosol secretion and down-regulate QS-related virulence genes CHK1 and PBS2 expressions.

Candida albicans ; drug effects ; genetics ; physiology ; Diterpenes ; pharmacology ; Farnesol ; analysis ; metabolism ; Gas Chromatography-Mass Spectrometry ; Genes, Fungal ; Phenylethyl Alcohol ; analogs & derivatives ; analysis ; metabolism ; Quorum Sensing ; drug effects ; Real-Time Polymerase Chain Reaction ; Virulence ; genetics

The extracting technology of salidroside, tyrosol, crenulatin and gallic acid from Rhodiolae Crenulatae Radix et Rhizoma was optimized. With extraction rate of salidroside, tyrosol, crenulatin and gallic acid as indexes, orthogonal test was used to evaluate effect of 4 factors on extracting technology, including concentration of solvent, the dosage of solvent, duration of extraction, and frequency of extraction. The results showed that, the best extracting technology was to extract in 70% alcohol with 8 times the weight of herbal medicine for 2 times, with 3 hours once. High extraction rate of salidroside, tyrosol, crenulatin and gallic acid were obtained with the present technology. The extracting technology was stable and feasible with high extraction rate of four compounds from Rhodiolae Crenulatae Radix et Rhizoma, it was suitable for industrial production.
Chemical Fractionation ; methods ; Chemistry, Pharmaceutical ; methods ; Coumarins ; isolation & purification ; Drugs, Chinese Herbal ; isolation & purification ; Gallic Acid ; isolation & purification ; Glucosides ; isolation & purification ; Phenols ; isolation & purification ; Phenylethyl Alcohol ; analogs & derivatives ; isolation & purification ; Rhizome ; chemistry ; Rhodiola ; chemistry

BACKGROUNDOsteoporosis (OP) is a common bone disease, which adversely affects life quality. Effective treatments are necessary to combat both the loss and fracture of bone. Recent studies indicated that caffeic acid phenethyl ester (CAPE) is a natural chemical compound from honeybee propolis which is capable of attenuating osteoclastogenesis and bone resorption. Therefore, this study aimed to investigate the effect of CAPE on bone loss in OP mice using micro-computed tomography (CT) and histology.

METHODSEighteen mice were prepared and evenly divided into three groups. The six mice in the sham+PBS group did not undergo ovariectomy and were intraperitoneally injected with PBS during the curing period. Twelve mice were ovariectomized (OVX) to induce OP. Six of them in the OVX+CAPE group were intraperitoneally injected with 0.5 mg/kg CAPE twice per week for 4 weeks after ovariectomy. The other six OVX mice in OVX+PBS group were treated with PBS. All the mice were sacrificed 4 weeks after ovariectomy. The tibias were bilaterally excised for micro-CT scan and histological analysis. The Mann-Whitney U test was used to test the statistical differences among groups.

RESULTSBone loss occurred in OVX mice. Compared with the sham+PBS group, mice in the OVX+PBS group exhibited a significant decrease in bone mineral density (BMD, P < 0.05), bone volume fraction (BV/TV, P < 0.01), trabecular thickness (Tb.Th, P < 0.05), and trabecular number (Tb.N, P < 0.01), as well as a non-insignificant increase in the number of osteoclasts (N.Oc/B.Pm). With CAPE treatment, the microarchitecture of the tibial metaphyses was significantly improved with a reduction of osteoclast formation. Compared with the OVX+PBS group, BV/TV in the OVX+CAPE group was significantly increased by 33.9% (P < 0.05).

CONCLUSIONCAPE therapy results in the protection of bone loss induced by OVX.

Animals ; Bone Density ; drug effects ; Caffeic Acids ; pharmacology ; Female ; Metabolism ; drug effects ; Mice ; Mice, Inbred C57BL ; Ovariectomy ; Phenylethyl Alcohol ; analogs & derivatives ; pharmacology ; Propolis ; chemistry ; Tomography, X-Ray Computed

OBJECTIVETo investigate the in vitro effect of caffeic acid phenethyl ester (CAPE), a NF-κB inhibitor, on the apoptosis of osteoarthritic (OA) chondrocytes and on the regulation of the gelatinases matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9).

METHODSAnnexin V-FITC/propidium iodide (PI) labeling and western blotting were used to observe and determine the apoptosis in TNFα-stimulated primary cultured osteoarthritic chondrocytes. Also, gelatin zymography was applied to examine MMP-2 and MMP-9 activities in supernatants.

RESULTSIt was confirmed by both flow cytometry and western blotting that chondrocytes from OA patients have an apoptotic background. Use of CAPE in combination with 10 ng/mL of TNFα for 24 h facilitated the apoptosis. MMP-9 in the supernatant could be autoactivated (from proMMP-9 to active MMP-9), and the physiologic calcium concentration (2.5 mmol/L) could delay the autoactivation of MMP-9. The activities of MMP-2 and MMP-9 in the fresh supernatant increased significantly in response to stimulation by 10 ng/mL of TNFα for 24 h. The stimulatory effect of TNFα just on proMMP-9 was counteracted significantly by CAPE.

CONCLUSIONNF-κB could prevent chondrocytes apoptosis though its activation was attributed to the increase of proMMP-9 activity induced by TNFα (a pro-apoptotic factor). Therefore, therapeutic NF-κB inhibitor was a 'double-edged swords' to the apoptosis of chondrocytes and the secretion of MMP-9.

Aged ; Apoptosis ; drug effects ; Caffeic Acids ; pharmacology ; therapeutic use ; Calcium ; physiology ; Cells, Cultured ; Chondrocytes ; drug effects ; enzymology ; secretion ; Drug Evaluation, Preclinical ; Female ; Humans ; Matrix Metalloproteinase 2 ; metabolism ; Matrix Metalloproteinase 9 ; metabolism ; Middle Aged ; NF-kappa B ; antagonists & inhibitors ; Osteoarthritis ; drug therapy ; enzymology ; Phenylethyl Alcohol ; analogs & derivatives ; pharmacology ; therapeutic use ; Tumor Necrosis Factor-alpha ; pharmacology

OBJECTIVETo observe the changes in the expressions of STAT3 and NF-KB in PC-3 cells after IL-6 stimulation and to verify the effects of the NF-KB inhibitor caffeic acid phenethyl ester (CAPE) on the expressions of p-STAT3 and IL-6 in the PC-3 prostate cancer cell line.

METHODSPC-3 prostate cancer cells were treated with IL-6 at 20 ng/ml for 5, 10, 20, 30 and 45 min. The protein and mRNA expressions of STAT3 and NF-kappaB were measured by Western blot and real time PCR, respectively, and the cell cycle was detected by flow cytometry. The PC-3 cells were exposed to TNF-alpha or TNF-alpha + CAPE, followed by determination of the IL-6 expression in the supernatant of the cells by ELISA and the expression of p-STAT3 by Western blot.

RESULTSAfter IL-6 stimulation, both the expression of p-STAT3 protein and the proliferation index of the PC-3 cells were significantly increased, and so were the expressions of IL-6 and p-STAT3 protein in the supernatant after TNF-alpha treatment (P < 0.05). TNF-alpha + CAPE induced statistically lower expressions of IL-6 and p-STAT3 than TNF-alpha alone (P < 0.05).

CONCLUSIONCAPE can inhibit IL-6 secretion induced by TNF-alpha in PC-3 cells and thus suppress STAT3 translocation. Therefore, by inhibiting the expression of NF-kappaB and affecting STAT3 and other related cell signaling pathways, CAPE may become a new therapeutic option for prostate cancer.

Caffeic Acids ; pharmacology ; Cell Line, Tumor ; Humans ; Interleukin-6 ; metabolism ; pharmacology ; Male ; NF-kappa B ; antagonists & inhibitors ; Phenylethyl Alcohol ; analogs & derivatives ; pharmacology ; Prostatic Neoplasms ; metabolism ; STAT3 Transcription Factor ; metabolism ; Signal Transduction ; drug effects ; Tumor Necrosis Factor-alpha ; pharmacology

Salidroside, the 8-O-beta-D-glucoside of tyrosol, is a novel adaptogenic drug extracted from the medicinal plant Rhodiola sachalinensis A. Bor. Due to the scarcity of R. sachalinensis and its low yield of salidroside, there is great interest in enhancing the production of salidroside by biotechnological process. Glucosylation of tyrosol is thought to be the final step in salidroside biosynthesis. In our related works, three UGT clones were isolated from the roots and the cultured cells. Our intention was to combine the catalytic specificity of these UGTs in vitro in order to change the level of salidroside in vivo by over-expression of the above UGTs. However, as the aglycone substrate of salidroside, the biosynthetic pathway of tyrosol and its regulation are less well understood. The results of related studies revealed that there are two different possibilities for the tyrosol biosynthetic pathway. One possibility is that tyrosol is produced from a p-coumaric acid precursor, which is derived mainly from phenylalanine. The second possibility is that the precursor of tyrosol might be tyramine, which is synthesized from tyrosine. Our previous work demonstrated that over-expression of the endogenous phenylalanine ammonia-lyase gene (PALrs1) and accumulation of p-coumaric acid did not facilitate tyrosol biosynthesis. In contrast, the data presented in our recent work provide in vitro and in vivo evidence that the tyrosine decarboxylase (RsTyrDC) is most likely to have an important function in the initial reaction of the salidroside biosynthesis pathway in R. Sachalinensis.
Genetic Engineering ; Glucosides ; biosynthesis ; Glycosylation ; Phenols ; Phenylethyl Alcohol ; analogs & derivatives ; chemistry ; metabolism ; Rhodiola ; metabolism ; Tyrosine ; metabolism ; Tyrosine Decarboxylase ; metabolism