Synthesis of curcuminoid-imprinted polymers applied to the solidphase extraction of curcuminoids from turmeric samples

A molecular imprinting polymer technique was successfully applied to precipitation polymerization by using styrene as a functional monomer, curcuminoids as templates, acetonitrile as a porogenic solvent,benzoyl peroxide as the initiator, and ethylene glycol dimethacrylate as the crosslinker. The effects of interaction on the adsorption capacity of the molecularly imprinted polymer(MIP) and non-imprinted polymer(NIP) were investigated. A comparison of the adsorption capacity for MIP and NIP indicated that the NIP had the lowest adsorption capacity. The curcuminoid-imprinted polymer(Cur-MIP) was synthesized from 0.0237 mmol of styrene, 47.0 g of acetonitrile, 1.0238 mmol of ethylene glycol dimethacrylate, 0.0325 mmol of curcuminoids, and 0.2480 mmol of benzoyl peroxide. A high-performance liquid chromatography method with fluorescence detection was developed and validated for various chromatographic conditions for the determination of the curcuminoids in turmeric samples. The sample solution was separated using the Cur-MIP via solid-phase extraction and analyzed on a Brownlee analytical C_(18) column(150 mm ×6 mm, 5 mm) using an isocratic elution consisting of acetonitrile and 0.1%trichloroacetic acid(40:60, v/v). The flow rate was maintained at 1.5 m L/min. The fluorescence detector was set to monitor at λex? 426 nm and λem? 539 nm. The quantification limit values were found to be16.66, 66.66, and 33.33 mg/L for curcumin, demethoxycurcumin, and bisdemethoxycurcumin, respectively. Thus, we concluded that the Cur-MIP and high-performance liquid chromatographic-fluorescence method could be applied to selective extraction and could be used as a rapid tool for the determination of curcuminoids in medicinal herbal extracts.

Effects of Two Curcuminoids on Candida albicans

Objective To investigate and compare the action of curcuminoids on the causal pathogens of Candida albicans growth. Methods The effects of curcumin (CUR) and demethoxycurcumin (DMC) on C. albicans growth were first investigated and compared by microcalorimetry coupled with multiple analytical methods. The quantitative thermo-kinetic parameters obtained from these curves were analyzed to show difference of the actions. Results By analyzing the main parameters screened from principal component analysis together with 50% inhibiting concentration values, it was demonstrated that both CUR and DMC showed good antifungal activities and CUR was stronger. It was further concluded from structure-activity relationship that the existence of methoxy group might enhance lipophilicity of the mother nucleus, which made it easier for the molecular to enter into the cell membrane of fungi to inhibit its growth. Conclusion This study provides a new method for screening new antifungal agents with high efficacy and low toxicity. Meanwhile, it contributes to the application of curcuminoids as food additive, colorant, and drug. Microcalorimetry is real-time, online, and dynamic, and it could be used to characterize the subtle difference among the effects of synthetic and natural products on the vital process of fungi.

High water-soluble curcuminoids-rich extract regulates osteogenic differentiation of MC3T3-E1 cells:Involvement of Wnt/β-catenin and BMP signaling pathway

Objective:The present study aimed to evaluate the effect of a high water-soluble curcuminoids-rich extract(CRE)in a solid dispersion form(CRE-SD)using polyvinylpyrrolidone K30 on osteogenic induction of MC3T3-E1 cells.Methods:CRE was pre-purified using a microwave assisted extraction couple with a Diaion;HP-20 column chromatography.The osteoblastic cell proliferation and differentiation potentials of CRE-SD in MC3T3-E1 cells were tested by cell viability,alkaline phosphatase(ALP)activity,and Alizarin red S activity assays.The m RNA expressions of osteoblast-specific genes and underline mechanisms were assessed by a real time PCR and western blot analysis.Results:CRE-SD 50μg/m L increased alkaline phosphatase(ALP)activity,an early differentiation marker of osteoblasts in both MC3T3-E1 cells and non-osteogenic mouse pluripotent cell line,C3H10T1/2,indicating the action of CRE-SD was not cell-type specific.Alizarin red S activity showed a significant amount of calcium deposition in cells treated with CRE-SD.CRE-SD also upregulated the m RNA expression levels of transcription factors that favor osteoblast differentiation including Bmp-2,Runx2 and Collagen 1 a,in a dose dependent manner.Western blot analysis revealed that noggin attenuated CRE-SD-promoted expressions of Bmp-2 and Runx2 proteins.si RNA mediated blocking of Wnt/β-catenin signaling pathway also annulled the influence of CRE-SD,indicating Wnt/β-catenin dependent activity.Inhibition of the different signaling pathways abolished the influence of CRE-SD on ALP activity,confirming that CRE-SD induced MC3T3-E1 cells into osteoblasts through Wnt/β-catenin and BMP signaling pathway.Conclusion:These results collectively demonstrate that CRE-SD may be a potential therapeutic agent for the treatment of osteoporosis.

Curcumin in inflammatory bowel diseases:Cellular targets and molecular mechanisms

Curcumin,a natural product,has exhibited promising effects in both animal models and clinical trials,interacting with a multitude of factors linked to Inflammatory Bowel Disease(IBD).These factors encompass cytokines,oxidative stress-associated enzymes,and modulation of the intestinal microbiota.Notably,curcumin has demonstrated therapeutic potential in animal models of colitis,wherein it exerts a negative regulatory influence on pivotal signaling pathways such as PI3/Akt,JAK/STAT,andβ-catenin.Moreover,it inhibits the expression of proinflammatory enzymes and co-stimulatory molecules(including RANKL,ICAM-1,CD205,CD256,TLR4,among others),while curbing immune cell chemotaxis,thereby attenuating the characteristic neutrophil infiltration observed in IBD.Another facet of curcumin’s action involves its modulation of the intestinal microbiota.Notably,the microbiota itself contributes to beneficial biotrans formations of curcumin,thereby enhancing its effectiveness in IBD treatment.On a clinical front,curcumin has demonstrated the ability to induce clinical and/or endoscopic remission without any reported toxic effects.Hence,curcumin warrants consideration as an adjunctive therapy in IBD management.Subsequent clinical investigations should concentrate on meticulously evaluating curcumin’s impact on these precise therapeutic targets.

miR-15b-5p targeting amyloid precursor protein is involved in the anti-amyloid eflect of curcumin in swAPP695-HEK293 cells

Curcumin exerts a neuroprotective effect on Alzheimer’s disease;however,it is not known whether microRNAs are involved in this protective effect.This study was conducted using swAPP695-HEK293 cells as an Alzheimer’s disease cell model.swAPP695-HEK293 cells were treated with 0,0.5,1,2,5,and 10μM curcumin for 24 hours.The changes in miR-15b-5p,miR-19a-3p,miR-195-5p,miR-101-3p,miR-216b-5p,miR-16-5p and miR-185-5p expression were assessed by real-time quantitative polymerase chain reaction.The mRNA and protein levels of amyloid precursor protein,amyloid-β40 and amyloid-β42 were evaluated by quantitative real-time polymerase chain reaction,western blot assays and enzyme-linked immunosorbent assays.swAPP695-HEK293 cells were transfected with miR-15b-5p mimic,or treated with 1μM curcumin 24 hours before miR-15b-5p inhibitor transfection.The effects of curcumin on amyloid precursor protein,amyloid-β40 and amyloid-β42 levels were evaluated by western blot assays and enzyme-linked immunosorbent assay.Luciferase assays were used to analyze the interaction between miR-15b-5p and the 3′-untranslated region of amyloid precursor protein.The results show that amyloid precursor protein and amyloid-βexpression were enhanced in swAPP695-HEK293 cells compared with HEK293 parental cells.Curcumin suppressed the expression of amyloid precursor protein and amyloid-βand up-regulated the expression of miR-15b-5p in swAPP695-HEK293 cells.In addition,we found a negative association of miR-15b-5p expression with amyloid precursor protein and amyloid-βlevels in the curcumin-treated cells.Luciferase assays revealed that miR-15b-5p impaired the luciferase activity of the plasmid harboring the 3′-untranslated region of amyloid precursor protein.These findings indicate that curcumin down-regulates the expression of amyloid precursor protein and amyloid-βin swAPP695-HEK293 cells,which was partially mediated by miR-15b-5p via targeting of the 3′-untranslated region of amyloid precursor protein.

Development of a multi-component drug from turmeric using central composite design

A methodology drugs based on traditional to develop multi-component Chinese medicines has been developed using central composite design. Several active components from the traditional Chinese medicine turmeric were chosen for use in a multi-component antitumor drug. Response surface methodology based on a central composite design was applied to determine the quantitative composition-activity relationships in order to optimize the amount of each component in the drug. An MTT （3-（4,5- dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide） assay was used to measure the pharmacological activity as the response value. The experimental antitumor activity of the optimum combination was 92.85% in the MTT assay and superior to the activities of each single component. These results demonstrate that response surface methodology based on a central composite design is suitable for the design of multi-component drugs.

Near-Infrared mitochondria-targeted fluorescent probe for cysteine based on difluoroboron curcuminoid derivatives

Curcuminoid difluoroboron has attractive performance as a promising near-infrared（NIR） fluorescent dye. In this contribution, we designed and synthesized a mitochondria-targeted NIR fluorescent probe DFB1 based on difluoroboron curcuminoid scaffold for the detection of Cys（cysteine）. DFB1 employs a curcumin analog as the NIR fluorophore, an acrylate group containing a, b-unsaturated ketone as a functional trigger moiety for Cys, and a triphenylphosphonium（TPP） cation moiety for specifically targeting mitochondria. The remarkable shift of DFB1 with Cys was observed from 470 nm to 590 nm in absorption spectra and from 560 nm to 680 nm in emission spectra. Notably, DFB1 manifests significantly dual-channel and turn-on NIR fluorescent signals simultaneously in response to Cys concentration,which make it favorable for monitoring endogenous Cys activity in vivo. This probe has high sensitivity and selectivity for the detection of Cys over homocysteine（Hcy） and glutathione（GSH）. This specific response for Cys was based on differences kinetics of intramolecular adduct/cyclizations. More importantly, biological experiments indicated that this probe could be utilized for the detection of endogenous mitochondrial Cys in living cells.

Functional characterization of key polyketide synthases by integrated metabolome and transcriptome analysis on curcuminoid biosynthesis in Curcuma wenyujin

Leaf and tuber extracts of Curcuma wenyujin contain a mixture of curcuminoids.However,the curcuminoid constituents and their molecular mechanisms are poorly understood,and the relevant curcumin synthases remain unclear.In this study,we comprehensively compared the metabolite profiles of the leaf and tuber tissues of C.wenyujin.A total of 11 curcuminoid metabolites were identified and exhibited differentially changed contents in the leaf and tuber tissues.An integrated analysis of metabolomic and transcriptomic data revealed the proposed biosynthesis pathway of curcuminoid.Two candidate type III polyketide synthases(PKSs)were identified in the metabolically engineering yeasts,indicating that CwPKS1 and CwPKS2 maintained substrate and product specificities.Especially,CwPKS1 is the first type III PKS identified to synthesize hydrogenated derivatives of curcuminoid,dihydrocurcumin and tetrehydrocurcumin.Interestingly,the substitution of the glycine at position 219 with aspartic acid(G219D mutant)resulted in the complete inactivation of CwPKS1.Our results provide the first comparative metabolome analysis of C.wenyujin and functionally identified type III PKSs,giving valuable information for curcuminoids biosynthesis.