Potential Mechanisms Involved in the Protective Effect of Dicaffeoylquinic Acids from Artemisia annua L. Leaves against Diabetes and Its Complications.

Diabetes mellitus is a chronic disease affecting the globe and its incidence is increasing pandemically. The use of plant-derived natural products for diabetes management is of great interest. Polar fraction of Artemisia annua L. leaves has shown antidiabetic activity in vivo. In the present study, three major compounds were isolated from this polar fraction; namely, 3,5-dicaffeoylquinic acid (1); 4,5-dicaffeoylquinic acid (2), and 3,4- dicaffeoylquinic acid methyl ester (3), using VLC-RP-18 and HPLC techniques. The potential protective effects of these compounds against diabetes and its complications were investigated by employing various in vitro enzyme inhibition assays. Furthermore, their antioxidant and wound healing effectiveness were evaluated. Results declared that these dicaffeoylquinic acids greatly inhibited DPPIV enzyme while moderately inhibited α-glucosidase enzyme, where compounds 1 and 3 displayed the most prominent effects. In addition, compound 3 showed pronounced inhibition of α-amylase enzyme. Moreover, these compounds markedly inhibited aldose reductase enzyme and exerted powerful antioxidant effects, among which compound 3 exhibited the highest activity implying a notable potentiality in impeding diabetes complications. Interestingly, compounds 2 and 3 moderately accelerated scratch wound healing. Our findings suggest that these dicaffeoylquinic acids can be promising therapeutic agents for managing diabetes and its complications.

Bioprospecting of Artemisia genus: from artemisinin to other potentially bioactive compounds.

Species from genus Artemisia are widely distributed throughout temperate regions of the northern hemisphere and many cultures have a long-standing traditional use of these plants as herbal remedies, liquors, cosmetics, spices, etc. Nowadays, the discovery of new plant-derived products to be used as food supplements or drugs has been pushed by the exploitation of bioprospection approaches. Often driven by the knowledge derived from the ethnobotanical use of plants, bioprospection explores the existing biodiversity through integration of modern omics techniques with targeted bioactivity assays. In this work we set up a bioprospection plan to investigate the phytochemical diversity and the potential bioactivity of five Artemisia species with recognized ethnobotanical tradition (A. absinthium, A. alba, A. annua, A. verlotiorum and A. vulgaris), growing wild in the natural areas of the Verona province. We characterized the specialized metabolomes of the species (including sesquiterpenoids from the artemisinin biosynthesis pathway) through an LC-MS based untargeted approach and, in order to identify potential bioactive metabolites, we correlated their composition with the in vitro antioxidant activity. We propose as potential bioactive compounds several isomers of caffeoyl and feruloyl quinic acid esters (e.g. dicaffeoylquinic acids, feruloylquinic acids and caffeoylferuloylquinic acids), which strongly characterize the most antioxidant species A. verlotiorum and A. annua. Morevoer, in this study we report for the first time the occurrence of sesquiterpenoids from the artemisinin biosynthesis pathway in the species A. alba.

Characterization of ultrasound-assisted covalent binding interaction between ß-lactoglobulin and dicaffeoylquinic acid: Great potential for the curcumin delivery.

The low bioavailability and poor gastrointestinal instability of curcumin hampers its application in pharmaceutical and food industries. Thus, it is essential to explore efficient carrier (e.g. a combination of polyphenols and proteins) for food systems. In this study, covalent ß-lactoglobulin (LG)-dicaffeoylquinic acids (DCQAs) complexes were prepared by combining ultrasound and free radical induction methods. Covalent interactions between LG and DCQAs were confirmed by analyzing reactive groups. Variations in secondary or tertiary structure and potential binding sites of covalent complexes were explored using Fourier transform infrared spectroscopy and circular dichroism. Results showed that the ß-sheet content decreased and the unordered content increased significantly (P < 0.05). The embedding rate of curcumin in prepared LG-DCQAs complexes using ultrasound could reach 49 % - 62 %, proving that complexes could embed curcumin effectively. This study highlights the benefit of ultrasound application in fabrication of protein-polyphenol complexes for delivering curcumin.

Water Extract of Desalted Salicornia europaea Inhibits RANKL-Induced Osteoclast Differentiation and Prevents Bone Loss in Ovariectomized Mice.

Osteoporosis, which is often associated with increased osteoclast activity due to menopause or aging, was the main focus of this study. We investigated the inhibitory effects of water extract of desalted Salicornia europaea L. (WSE) on osteoclast differentiation and bone loss in ovariectomized mice. Our findings revealed that WSE effectively inhibited RANKL-induced osteoclast differentiation, as demonstrated by TRAP staining, and also suppressed bone resorption and F-actin ring formation in a dose-dependent manner. The expression levels of genes related to osteoclast differentiation, including NFATc1, ACP5, Ctsk, and DCSTAMP, were downregulated by WSE. Oral administration of WSE improved bone density and structural parameters in ovariectomized mice. Dicaffeoylquinic acids (DCQAs) and saponins were detected in WSE, with 3,4-DCQA, 3,5-DCQA, and 4,5-DCQA being isolated and identified. All tested DCQAs, including the aforementioned types, inhibited osteoclast differentiation, bone resorption, and the expression of osteoclast-related genes. Furthermore, WSE and DCQAs reduced ROS production mediated by RANKL. These results indicate the potential of WSE and its components, DCQAs, as preventive or therapeutic agents against osteoporosis and related conditions.

Influence of the Abiotic Elicitors Ag Salts of Aspartic Acid Derivatives, Self-Organized in Nanofibers with Monomeric and Dimeric Molecular Structures, on the Antioxidant Activity and Stevioside Content in Micropropagated Stevia rebaudiana Bert.

The use of nanomaterials in biotechnology for the in vitro propagation of medical plants and the accumulation of certain biologically active metabolites is becoming an efficient strategy. This study aimed to evaluate the influence of the concentration (0, 1, 10, 50, and 100 mg L-1) of two types of nanofibers on the growth characteristics, the antioxidant status, and the production of steviol glycosides in micropropagated Stevia rebaudiana Bert. plantlets. The nanofibers were synthesized by aspartic acid derivatives (L-Asp) Ag salts self-organized into nanofibers with two different molecular structures: monomeric, containing one residue of L-Asp with one hydrophilic head which bonds one Ag ion (NF1-Ag salt); and dimeric, containing two residues of L-Asp with two hydrophilic heads which bond two Ag ions (NF2-Ag salt). An increase in the shoots from the explants' number and length, biomass accumulation, and micropropagation rate was achieved in the plants treated with the NF1-Ag salt in concentrations from 1 to 50 mg L-1 after 30 days of in vitro proliferation compared to the NF2-Ag salt. In contrast, the plants grown on MS media supplemented with NF2-Ag salt exhibited an increase in the level of stevioside, rebaudioside A, and mono- (CQA) and dicaffeoylquinic (DCQA) acids as compared to the NF1-Ag salt.

New Eudesmane-Type Sesquiterpene Glycosides from the Leaves of Aster koraiensis.

Four new eudesmane-type sesquiterpenoids, (1R,5S,6R,7S,9S,10S)-1,6,9-trihydroxy-eudesm-3-ene-1,6-di-O-ß-d-glucopyranoside (1), (1R,5S,6S,7R,9S,10S)-1,6,9,11-tetrahydroxy-eudesm-3-ene-1,6-di-O-ß-d-glucopyranoside (3), (1R,5S,6R,7S,9S,10R)-9-O-(Z-p-coumaroyl)-1,6,9-trihydroxy-eudesm-3-ene-6-O-ß-d-glucopyranoside (6), and (1R,5S,6R,7S,9S,10R)-9-O-(E-feruloyl)-1,6,9-trihydroxy-eudesm-3-ene-6-O-ß-d-glucopyranoside (7), were isolated from a 95% EtOH extract of the leaves of Aster koraiensis by repeated chromatography. Moreover, three sesquiterpenoids (2, 4, and 5) and two caffeoylquinic acids (8 and 9) having previously known chemical structures were isolated during the isolation procedure. The four new compounds (1, 3, 6, and 7) were elucidated by spectroscopic data (1D- and 2D-NMR, MS, and ECD) interpretation and hydrolysis. Moreover, the absolute configurations of 2, 4, and 5 were determined for the first time in this study. The compounds isolated were tested for their viability on nitric oxide (NO) and prostaglandin E2 (PGE2) production on LPS-stimulated RAW 264.7 cells. Among them, only 7 presented weak inhibitory effects on both NO and PGE2 production.

Organic anion transporter 3 (OAT3)-mediated transport of dicaffeoylquinic acids and prediction of potential drug-drug interaction.

Dicaffeoylquinic acids (DCQAs) are widely distributed in daily food and herb medicine (such as Dengzhanxiyin injection) with multiple health benefits and pharmacological activities. However, drug-drug Interactions (DDIs) between DCQAs and possible concomitant drugs were not fully understood in clinic. The purpose of present study was to investigate the role of organic anion transporters (OATs) in the transport of DCQAs and to explore the potential clinical DDIs using in vitro transporter assays. Uptake study using hOAT1/hOAT3-transfected HEK293 cells revealed that none of DCQAs was OAT1 substrate, while 3,4-DCQA, 3,5-DCQA, and 4,5-DCQA were substrates of OAT3 with Km values of 119.7 ±â€¯28.8, 269.3 ±â€¯129.5 and 53.2 ±â€¯32.1 µM, respectively. The docking analysis revealed that 3,4-DCQA, 3,5-DCQA, and 4,5-DCQA were effectively embedded in the active site of OAT3 and fitted well with the cavity in three-dimensional space. Moreover, the classical substrates/inhibitors of OAT decreased the accumulation of 3,4-DCQA, 3,5-DCQA, and 4,5-DCQA in kidney slices, suggesting potential DDI risks with co-administration of substrate drugs of OAT. In fact, antivirals, antibiotics, neuroprotective agents, and PPIs (proton pump inhibitors) all showed varying degrees of inhibition of OAT3-mediated uptake of 3,4-DCQA, 3,5-DCQA, and 4,5-DCQA in vitro. For cefaclor, ceftizoxime, pantoprazole, and zidovudine, in particular, their IC50 values were <10 times the maximal free plasma concentration, indicating potential clinically relevant DDIs when used together with DCQAs. These findings provided useful information for the prediction of DDIs between DCQAs and OAT3 inhibitors, and rational application of herbal medicines containing DCQAs in clinic.

Effects of Dicaffeoylquinic Acids from Ilex kudingcha on Lipid Metabolism and Intestinal Microbiota in High-Fat-Diet-Fed Mice.

Kudingcha made from the leaves of Ilex kudingcha and chlorogenic acid have antiobesity and intestinal microbiota modulating effects. However, the effects of kudingcha dicaffeoylquinic acids (diCQAs) on obesity and intestinal microbiota are still poorly understood. In the present study, the effects of kudingcha diCQAs on adipose accumulation and intestinal microbiota were investigated in high-fat-diet-fed mice. As a result, kudingcha diCQAs decreased the liver and adipose tissue masses, concentrations of serum inflammatory factors, and hepatic expressions of lipid synthesis related genes and increased the expressions of genes involved in lipid degradation in the liver. Kudingcha diCQAs also exhibited considerable effects on intestinal microbiota. They increased the relative abundances of Bifidobacterium and Akkermansia and affected the function of the microbial community including bile acid biosynthesis. Kudingcha diCQAs had antiobesity potential, possibly acting through affecting intestinal microbiota. Furthermore, the effects of kudingcha diCQAs on fat accumulation and intestinal microbiota had a dose-dependent manner.

Simultaneous determination of three di-caffeoylquinic acids by UHPLC-MS/MS in rat plasma and its application to a comparative pharmacokinetic study in normal and acute lung injury rat.

Acute lung injury (ALI) is a severe inflammatory disease with high mortality rates. Di-caffeoylquinic acids (DCQAs), the bioactive components of reduning injection (RDN), may play important roles in the protective effect on acute lung injury (ALI). A selective and rapid ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method has been developed and validated for the simultaneous determination of 3,4-, 3,5- and 4,5-DCQA in rat plasma. The DCQAs were extracted by liquid-liquid extraction with ethyl acetate-isopropyl alcohol (7:3, v/v). Chromatographic separation was accomplished on a C18 column using gradient elution. Detection was performed in the multiple reaction monitoring (MRM) mode. The lower limits of quantification were all 2.0ng/mL for the three analytes. Intra-day and inter-day precision were less than 15% and accuracy ranged from -13.8% to 10.0%, and the mean extraction recoveries of analytes from rat plasma were all more than 72.9%. Meanwhile, this method had been successfully applied to compare the pharmacokinetics of the three DCQAs in normal and ALI model rat after RDN was given intravenously administration. The pharmacokinetic parameters of the 3,4-, 3,5- and 4,5- DCQA were remarkably different from those in normal rats. It might result from the effects of the pathological status of ALI. This study presented a meaningful basis for the clinical applications of RDN when used in the treatment of ALI.

Identification of anti-inflammatory constituents from Kalimeris indica with UHPLC-ESI-Q-TOF-MS/MS and GC-MS.

ETHNOPHARMACOLOGICAL RELEVANCE: Kalimeris indica is a Miao׳s medicinal plant in Guizhou province of China employing to treat various inflammation-related diseases in clinical. The study aims to determine the active fractions of K. indica for its anti-inflammatory activity and to identify their chemical constituents. MATERIAL AND METHODS: The dried K. indica herb was extracted with 50% aqueous ethanol and then successively separated with macroporous resin and MCI column chromatography to give five fractions (A-E). The anti-inflammatory effects were determined by measuring the NO and TNF-α production in murine macrophage RAW 264.7 cells after exposure to LPS. The chemical constituents of the anti-inflammatory fractions were analyzed by the method of UHPLC-ESI-Q-TOF/MS or GC-MS. RESULTS: Five fractions (A-E) of different polarities were prepared from the 50% ethanol extract. Factions C and E showed significant inhibition of NO and TNF-α production. Six constituents, namely 3,4-dicaffeoylquinic acid (1), 3,5-dicaffeoylquinic acid (2), 1,5-dicaffeoylquinic acid (3), rutin (4), 1-malonyl-3,5-dicaffeoylquinic acid (5), and 4,5-dicaffeoylquinic acid (6) were identified from the active fraction C by UHPLC-ESI-Q-TOF/MS. Four compounds including 13-tetradecenal (7), (Z,Z)-9,12-octadecadienoic acid (8), (3α)-12-oleanen-3-yl acetate (9), and (+)-3-oxo-urs-12-en-24-oic acid methyl ester (10) were identified from the active fraction E by GC-MS. CONCLUSION: K. indica possessed pronounced anti-inflammatory effect. Dicaffeoylquinic acids and their dirivatives, rutin, as well as oleanolic and fatty acid derivatives are the major constituents and possibly the anti-inflammatory principles of the active fractions of K. indica. All the compounds were identified in K. indica for the first time. The work provided evidence for further development and utilization of K. indica and formed a basis for the establishment of quality control methods and standards for K. indica and its pharmaceutical preparations.

Comparative pharmacokinetics and tissue distribution study of mono-, and di-caffeoylquinic acids isomers of Ainsliaea fragrans Champ by a fast UHPLC-MS/MS method.

Ainsliaea fragrans Champ, as a well-known herb in Traditional Chinese Medicine, was often used in the treatment of gynecological diseases. Caffeoylquinic acids (CQAs) were the bioactive constituents of this plant medicine which primarily contains mono-CQAs (MCQA) and di-CQAs (DCQA). The biosynthesis showed that MCQAs were the precursor of DCQAs. Recent literatures manifested some particular features of DCQAs, different from MCQAs. Therefore it is apparent that a complete and scientific assessment of DCQAs and MCQAs should include not only the DCQAs' pharmacokinetics and distribution but also its degradation products. So an efficient, sensitive rapid resolution liquid chromatography/tandem mass spectrometry (UHPLC-MS/MS) method for the simultaneous determination of the active ingredients in rat plasma and different tissues had been developed and validated. Mass spectrometric detection was performed by selected reaction monitoring mode (MRM) via an electrospray ionization source operating in negative ionization mode. The method was validated in plasma and tissue samples, which showed good linearity over a wide concentration range (r(2)>0.99), and obtained lower limit of quantification (LLOQ) was 2.34 ng·mL(-1) for the analytes in biological samples. The intra- and inter-day assay variability was less than 15%, and the accuracy was between -8.8% and 5.7%. This study provided the pharmacokinetic profiles and the tissue regional distribution of MCQAs, DCQAs and caffeic acid. The results indicated that the DCQAs isomers were absorbed quickly after oral administration and degradation products MCQAs were mostly found in tissues, not in plasma. Besides, 1,5-DCQA was the prior configuration for the isomerization phenomenon. The small intestine was the main absorption site for DCQAs. Interestingly, the content of the DCQA and MCQA isomers was all high in the ovary and uterus, and some could pass through the barrier between the blood and brain obviously.

Pretreatment of SH-SY5Y cells with dicaffeoylquinic acids attenuates the reduced expression of nicotinic receptors, elevated level of oxidative stress and enhanced apoptosis caused by ß-amyloid peptide.

OBJECTIVES: This in vitro investigation was designed to examine potential neuroprotection by dicaffeoylquinic acids (diCQAs) extracted from a traditional Chinese medicinal herb herba erigerontis and their effects against the toxicity induced by ß-amyloid peptide (Aß25-35 ). METHODS: The neuroblastoma SH-SY5Y cell line was treated with Aß or 3, 4-diCQA, 3, 5-diCQA or 4, 5-diCQA. 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) reduction was assayed by spectrophotometrical method, lipid peroxidation (malondialdehyde) on the basis of the level of thiobarbituric acid-reactive substance, the activity of superoxide dismutase by the xanthine oxidase procedure, the frequency of apoptosis by flow cytometry, and the levels of α3 and α7 nicotinic acetylcholine receptor (nAChR) subunit proteins by Western blotting. KEY FINDINGS: When the cells were exposed to Aß25-35 , MTT reduction declined, oxidative stress and apoptosis were enhanced, and the expression of α3 and α7 nAChR subunit proteins was lowered. Expression of the α7 nAChR subunit protein was increased by all three diCQAs, and the level of α3 was increased by 3, 5-diCQA and 4, 5-diCQA. Significantly, pretreatment with diCQAs attenuated the neurotoxic effects of Aß25-35 , a neuroprotective effect in which the upregulation of α7 and α3 nAChR may be involved. CONCLUSION: The diCQAs exert a protective effect on Aß-induced neurotoxicity in SH-SY5Y cells and a potential underlying mechanism involving stimulation of nAChRs.

Antioxidant and genoprotective effects of spent coffee extracts in human cells.

Spent coffee has been shown as a good source of hydrophilic antioxidant compounds. The ability of two spent coffee extracts rich in caffeoylquinic acids, mainly dicaffeoylquinic acids, and caffeine (Arabica filter and Robusta espresso) to protect against oxidation and DNA damage in human cells (HeLa) was evaluated at short (2 h) and long (24 h) exposure times. Cell viability (MTT) was not affected by spent coffee extracts (>80%) up to 1000 µg/mL after 2 h. Both spent coffee extracts significantly reduced the increase of ROS level and DNA strand breaks (29-73% protection by comet assay) induced by H2O2. Pretreatment of cells with robusta spent coffee extract also decreased Ro photosensitizer-induced oxidative DNA damage after 24 h exposure. The higher effectiveness of Robusta spent coffee extract, with less caffeoylquinic acids and melanoidins, might be due to other antioxidant compounds, such as caffeine and other Maillard reaction products. This work evidences the potential antioxidant and genoprotective properties of spent coffee in human cells.