Protective Effect of Que Zui Tea on d-Galactose-Induced Oxidative Stress Damage in Mice via Regulating SIRT1/Nrf2 Signaling Pathway.

Que Zui tea (QT) is an important herbal tea in the diet of the 'Yi' people, an ethnic group in China, and it has shown significant antioxidant, anti-inflammatory, and hepatoprotective effects in vitro. This study aims to explore the protective effects of the aqueous-ethanol extract (QE) taken from QT against ᴅ-galactose (ᴅ-gal)-induced oxidative stress damage in mice and its potential mechanisms. QE was identified as UHPLC-HRMS/MS for its chemical composition and possible bioactive substances. Thus, QE is rich in phenolic and flavonoid compounds. Twelve compounds were identified, the main components of which were chlorogenic acid, quinic acid, and 6'-O-caffeoylarbutin. Histopathological and biochemical analysis revealed that QE significantly alleviated brain, liver, and kidney damage in ᴅ-gal-treated mice. Moreover, QE remarkably attenuated oxidative stress by activating the Nrf2/HO-1 pathway to increase the expression of antioxidant indexes, including GSH, GSH-Px, CAT, SOD, and T-AOC. In addition, QE administration could inhibit the IL-1ß and IL-6 levels, which suppress the inflammatory response. QE could noticeably alleviate apoptosis by inhibiting the expressions of Caspase-3 and Bax proteins in the brains, livers, and kidneys of mice. The anti-apoptosis mechanism may be related to the upregulation of the SIRT1 protein and the downregulation of the p53 protein induced by QE in the brain, liver, and kidney tissues of mice. Molecular docking analysis demonstrated that the main components of QE, 6'-O-caffeoylarbutin, chlorogenic acid, quinic acid, and robustaside A, had good binding ability with Nrf2 and SIRT1 proteins. The present study indicated that QE could alleviate ᴅ-gal-induced brain, liver and kidney damage in mice by inhibiting the oxidative stress and cell apoptosis; additionally, the potential mechanism may be associated with the SIRT1/Nrf2 signaling pathway.

Bioassay guided isolation of caffeoylquinic acids from the leaves of Ilex pubescens Hook. et Arn. and investigation of their anti-influenza mechanism.

ETHNOPHARMACOLOGICAL RELEVANCE: Ilex pubescens Hook. et Arn. (Maodongqing, MDQ) is a common herbal tea ingredient in Southern China for heat clearance and anti-inflammation. Our preliminary screening showed that 50% ethanol extract of its leaves has anti-influenza virus activity. In this report, we proceed to identify the active components and clarify the related anti-influenza mechanisms. AIM: We aim to isolate and identify the anti-influenza virus phytochemicals from the extract of the MDQ leaves, and study their anti-influenza virus mechanism. MATERIAL AND METHODS: Plaque reduction assay was used to test the anti-influenza virus activity of fractions and compounds. Neuraminidase inhibitory assay was used to confirm the target protein. Molecular docking and reverse genetics were used to confirm the acting site of caffeoylquinic acids (CQAs) on viral neuraminidase. RESULTS: Eight CQAs, 3,5-di-O-caffeoylquinic acid methyl ester (Me 3,5-DCQA), 3,4-di-O-caffeoylquinic acid methyl ester (Me 3,4-DCQA), 3,4,5-tri-O-caffeoylquinic acid methyl ester (Me 3,4,5-TCQA), 3,4,5-tri-O-caffeoylquinic acid (3,4,5-TCQA), 4,5-di-O-caffeoylquinic acid (4,5-DCQA), 3,5-di-O-caffeoylquinic acid (3,5-DCQA), 3,4-di-O-caffeoylquinic acid (3,4-DCQA), and 3,5-di-O-caffeoyl-epi-quinic acid (3,5-epi-DCQA) were identified from the MDQ leaves, in which Me 3,5-DCQA, 3,4,5-TCQA and 3,5-epi-DCQA were isolated for the first time. All these eight compounds were found to inhibit neuraminidase (NA) of influenza A virus. The results of molecular docking and reverse genetics indicated that 3,4,5-TCQA interacted with Tyr100, Gln412 and Arg419 of influenza NA, and a novel NA binding groove was found. CONCLUSION: Eight CQAs isolated from the leaves of MDQ were found to inhibit influenza A virus. 3,4,5-TCQA was found to interact with Tyr100, Gln412 and Arg419 of influenza NA. This study provided scientific evidence on the use of MDQ for treating influenza virus infection, and laid the foundation for the development of CQA derivatives as potential antiviral agents.

Investigation of the phytochemical composition and remedial effects of southern grape hyacinth (Muscari neglectum Guss. ex Ten.) plant extract against carbon tetrachloride-induced oxidative stress in rats.

We aimed to determine the phytochemical contents of the aerial part M. neglectum aerial part (MAP) and M. neglectum bulb (MB) ethanolic extract of Muscari neglectum and to investigate their protective effects on gastric damage induced by carbon tetrachloride (CCl4) in rats. After the toxicity testing, 42 female Wistar albino rats were divided into 7 groups, Control, MAP, MB, CCl4, CCl4 + MAP, CCl4 + MB, and CCl4 + Silymarin groups. At the end of the experiment, the serum biochemical parameters, antioxidant defense enzymes, and malondialdehyde (MDA) contents in the stomach tissue were evaluated to determine the antioxidant role of the M. neglectum extracts. According to the gas chromatography-mass spectroscopy, fatty acid analysis, octadecadienoic, and 9,12,15 octadecatrienoic fatty acids were found as major fatty acids in the MAP, whereas 9,12 octadecadienoic and octadecanoic acids were the major fatty acids in the MB. According to the liquid chromatography-tandem mass spectrometry, quinic acid, fumaric acid, gentisic acid, caffeic acid, kaempferol, and apigenin were found in the MAP, while quinic acid, fumaric acid, caffeic acid, and kaempferol were found in the MB. The total phenolic and flavonoid contents in the extract were determined in the MAP and MB. The MAP and MB extracts generally caused a statistically significant decrease in the MDA content and increase in the antioxidant parameters in the stomach tissue. It was concluded that MAP and MB extracts may have antioxidant and gastric protective effects due to the phytochemical content of M. neglectum.HighlightsAccording to LC-MS/MS results, quinic acid, fumaric acid, chemferol, apigenin, and caffeic acid were determined as major compounds in M. neglectum extracts.According to GC-MS results, octadecadienoic, octadecatrienoic, and octadecanoic methyl esters were the major fatty acids of the M. neglectum extracts.The M. neglectum extracts regulated the levels of stomach damage and biochemical parameters.The M. neglectum extracts extract might have pharmaceutical-nutritional potential.

Multispectroscopic and Computational Investigations on the Binding Mechanism of Dicaffeoylquinic Acids with Ovalbumin.

Recently, studies on the interactions between ovalbumin (OVA) and polyphenols have received a great deal of interest. This study explored the conformational changes and the interaction mechanism of the binding between OVA and chlorogenic acid (CGA) isomers such as 3,4-dicaffeoylquinic acids (3,4-diCQA), 4,5-dicaffeoylquinic acids (4,5-diCQA), and 3,5-dicaffeoylquinic acids (3,5-diCQA) using multispectroscopic and in silico analyses. The emission spectra show that the diCQAs caused strong quenching of OVA fluorescence under different temperatures through a static quenching mechanism with hydrogen bond (H-bond) and van der Waals (vdW) interactions. The values of binding constants (OVA-3,4-diCQA = 6.123 × 105, OVA-3,5-diCQA = 2.485 × 105, OVA-4,5-diCQA = 4.698 × 105 dm3 mol-1 at 298 K) suggested that diCQAs had a strong binding affinity toward OVA, among which OVA-3,4-diCQA exhibits higher binding constant. The results of UV-vis absorption and synchronous fluorescence indicated that the binding of all three diCQAs to OVA induced conformational and micro-environmental changes in the protein. The findings of molecular modeling further validate the significant role of vdW force and H-bond interactions in ensuring the stable binding of OVA-diCQA complexes. Temperature-dependent molecular dynamics simulation studies allow estimation of the individual components that contribute to the total bound free energy value, which allows evaluation of the nature of the interactions involved. This research can provide information for future investigations on food proteins' physicochemical stability and CGA bioavailability in vitro or in vivo.

The Q-system: A Versatile Repressible Binary Expression System.

Binary expression systems are useful genetic tools for experimentally labeling or manipulating the function of defined cells. The Q-system is a repressible binary expression system that consists of a transcription factor QF (and the recently improved QF2/QF2w), the inhibitor QS, a QUAS-geneX effector, and a drug that inhibits QS (quinic acid). The Q-system can be used alone or in combination with other binary expression systems, such as GAL4/UAS and LexA/LexAop. In this review chapter, we discuss the past, present, and future of the Q-system for applications in Drosophila and other organisms. We discuss the in vivo application of the Q-system for transgenic labeling, the modular nature of QF that allows chimeric or split transcriptional activators to be developed, its temporal control by quinic acid, new methods to generate QF2 reagents, intersectional expression labeling, and its recent adoption into many emerging experimental species.

Protective effect of D-(-)-quinic acid as food supplement in modulating AMP-activated protein kinase signalling pathway activation in HFD induced obesity.

BACKGROUND: Dietary quinic acid given as the nutritional supplement, which may leads to tryptophan and nicotinamide production in the intestinal tract and NAD+ precursor which can prevent from the negative consequences of high fat diet (HFD) consumption. OBJECTIVE: The present study was designed to assess in vivo and in vitro effect of D-(-)-Quinic acid in high-fat diet induced hyperlipidemia in mice. MATERIAL AND METHODS: Thirty six albino mice were randomly divided in six groups and each group had six mice. Group I, controlled mice given normal pellet diet, Group-II mice, administered with high fat diet (HFD), Group-III mice given standard drug, Atorvastatin (20 mg/kg, p.o.) along with HFD to mice and Group IV, V and VI mice received D-(-)-Quinic acid at a dose of 75, 150 and 300 mg/kg, respectively in separate group along with HFD to mice. After completion of trial (49 days) the animals were sacrificed and evaluated for body weight, organ fat pad weight, and changes in weight of liver, heart and kidney and also for biochemical parameters, expression of adipogenic and inflammation markers in adipose tissues, and histology examination of liver tissue. RESULTS: In vitro testing results showed, D-(-)-Quinic acid potentially inhibit α-glucosidase enzyme activity as compared to acarbose. The D-(-)-Quinic acid showed significant hypolipidemic activity by decreasing the increased level of cholesterol, triglyceride level, LDL, VLDL and other hepatic parameters like SGOT and SGPT in serum. D-(-)-Quinic acid reduces the mRNA expression level of PPAR-γ2, TNF-α, IL-1ß and IL-6 in adipose tissue in hyperlipidemic mice.

Ameliorative role of Cyanus depressus (M.Bieb.) Soják plant extract against diabetes-associated oxidative-stress-induced liver, kidney, and pancreas damage in rats.

In this original article, we aimed to assess the ameliorative role of Cyanus depressus (CD) plant ethanolic extract treatment of streptozotocin (STZ)-induced liver, kidney, and pancreas damage in rats. The rats were divided into five groups (n = 7): control, CD, Diabetes mellitus (DM), DM + CD, and DM + glibenclamide (Gly). The DM groups were injected with a single dose of 50 mg/kg STZ intraperitoneally (i.p.). While the CD and DM + CD groups received 400 mg/kg/day intragastrically for 21 days, the DM + Gly group received 3 mg/kg/day of Gly intragastrically throughout the experiment. Statistically significance was accepted as p < .05. According to our liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) data, quinic acid, cosmosiin, nicotiflorin, apigenin, and protocatechuic acid were the major compounds, in descending order. Weekly blood glucose, serum glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and urea, malondialdehyde (MDA) (liver and pancreas), and blood glycosylated hemoglobin % (HbA1c %) were significantly decreased, whereas finally live body weights (LBWs), reduced glutathione (GSH), glutathione S-transferase (GST) and catalase (CAT) (pancreas), and pancreatic islet diameter and area were increased significantly in the CD-treated diabetic group. Moreover, CD administration was found to be effective in the protection of the histology of the liver, kidneys, and pancreatic islets in the STZ-induced rats. Consequently, we concluded that CD administration reduces hyperglycemia, oxidative stress, and histopathology in STZ-induced experimental rats by improving antioxidant defenses. PRACTICAL APPLICATIONS: Today, the prevalence of diabetes is increasing rapidly throughout the world and it causes complications such as kidney damage, blindness, amputations, and cardiovascular diseases. Despite medical technological advances, people's interest in medicinal herbal products is gradually increasing. Biochemical and histopathological findings showed that the use of the plant CD at the determined dose (400 mg/kg/day) in rats with DM by STZ had strong antioxidant and antidiabetic effects. CD may have a drug potential in preventing DM and its complications because of its phytochemical content including some phenolic acids such as quinic acid, cosmosiin, nicotiflorin, apigenin, and protocatechuic acid. Isolation of bioactive compounds from CD and investigation of their therapeutic effects could be planned as further studies.

Quinic and Digallic acids from Pistacia atlantica Desf. Leaves Extracts as Potent Dual Effect Inhibitors against main Protease and RNA-dependent RNA Polymerase of SARS-CoV-2.

BACKGROUND: Through this study, the Chemical composition realized by UHPLC-DADESI- MSn allowed the detection of different phenolic compound groups from Pistacia atlantica Desf. leaves extracts. We studied the inhibition of main protease (CL3 Mpro) and RNA-dependent RNA polymerase (RdRp) of the SARS-CoV-2 by the identified molecules through molecular docking. OBJECTIVE: The objective of this study is to identify compounds from Pistacia atlantica Desf. leaves extracts, which might have anti-viral effects. METHODS: Chemical composition was realized by UHPLC-DAD-ESI-MSn, and the inhibition of the main protease (CL3 Mpro) and RNA-dependent RNA polymerase (RdRp) of the SARS-CoV-2 was studied using molecular docking with Autodock Vina software. ADMET analysis was carried out. RESULTS: The identified compounds are quinic acid, digallic acid, galloylquinic acid, gallic acid, trigallic acid, digalloylquinic acids, trigalloylquinic acids and methyl gallate; digallic and quinic acids are the best inhibitors. Digallic acid had binding affinity energy (BAE) of -8.2 kcal/mol, and Ki of 1µM for the CL3 Mpro, Ki of 0.62 mM for the RdRp. Quinic acid showed Ki of 4.6 mM, recorded for both enzymes. Through ADMET analysis, we have found that the two molecules are good drug candidates. CONCLUSION: This is the first time that a group of identified compounds from Pistacia atlantica Desf. leaves are studied for their potential activity against the novel virus by inhibiting two key enzymes in its life cycle, and no further studies have been published in this context.

(-)-5-O-(3-O-ß-d-Glucopyranosylcaffeoyl)-quinic acid from the fruits of Lycium barbarum L. var. auranticarpum K. F. Ching: Purification, identification and in vitro bioactivities.

Chlorogenic acids are important phenolics in the fruits of wolfberry, but little attention has been paid on their glucosylated forms. In the present study, a glucosylated form of chlorogenic acid was isolated from the fruits of Lycium barbarum L. var. auranticarpum K. F. Ching (also called yellow wolfberry) and identified to be (-)-5-O-(3-O-ß-d-glucopyranosylcaffeoyl)-quinic acid (5-CQA-3'ßG) by high resolution mass spectrometry and nuclear magnetic resonance spectrometry. The content of 5-CQA-3'ßG in the dried fruit was determined as 0.0293 ± 0.0015% by HPLC. In addition, 5-CQA-3'ßG showed a good scavenging capacity for 2,2'-azino-bis-(3-ethylben-zothiazoline-6-sulphonate) free radicals but had a relatively low reducing power and scavenging capacity for 2,2-diphenyl-1-picrylhydrazyl free radical. Moreover, the secretion of nitric oxide, tumor necrosis factor-α and interleukin-6 as well as related mRNA expression were reduced in lipopolysaccharide-stimulated RAW264.7 macrophage cells treated with 5-CQA-3'ßG. This is the first report describing purification, identification and bioactivity of glucosylated CQA from yellow wolfberry.

3,4,5-O-tricaffeoylquinic acid with anti-radiation activity suppresses LPS-induced NLRP3 inflammasome activation via autophagy in THP-1 macrophages.

Damage to normal tissues caused by excessive ionizing radiation (IR) exposure is the major side effect of radiotherapy. Several recent studies have shown that IR-induced damage to tissues leads to a systemic immune response and NLRP3 inflammasome activation in immune cells. 3,4,5-O-tricaffeoylquinic acid (tCQA), extracted from the natural plant Azolla imbricata, relieves inflammation and has radioprotective function. Here, we aimed to investigate the inhibitory effect and molecular mechanism of tCQA on IR-induced NLRP3 inflammasome activation. First, the results of ELISA and qPCR assays showed that tCQA has anti-inflammatory effects in THP-1 cell line and healthy human peripheral blood mononuclear cells. Western blotting and ELISA suggested tCQA could inhibit NF-κB/MAPK signaling pathway, NLRP3 expression and the secretion of IL-1ß in lipopolysaccharide (LPS)-stimulated THP-1 macrophages. Then, flow cytometry, LDH assay and western blotting demonstrated that tCQA could inhibit LPS- and nigericin-induced Caspase-1 activation and gasdermin D cleavage, thereby suppressing inflammatory cell death. Furthermore, we found that the autophagy inhibitor chloroquine, not the proteasome inhibitor MG132, could counteract the promoting effect of tCQA on NLRP3 degradation and the inhibitory effect on cell death. Western blotting and autophagosome staining results suggested tCQA could significantly enhance LPS-induced autophagic flux in macrophages and ATG5/ATG7 knockdown reverses the inhibitory effect of tCQA on NLRP3 expression and Caspase-1 activation, indicating that tCQA induces NLRP3 degradation via autophagy. Finally, THP-1 macrophages and BALB/c mice were irradiated with 137Cs γ-rays and tCQA could inhibit IR-induced NLRP3 inflammasome activation both in vitro and in vivo. To conclude, tCQA controls inflammation and NLRP3 inflammasome activation in vitro via NF-κB/MAPK signaling pathway and autophagy, meanwhile inhibits IR-induced NLRP3 inflammasome activation in vivo. Overall, our study provides an experimental and theoretical basis for the application of tCQA as a radioprotectant in clinical radiotherapy.

Synergistic effects of trans-p-coumaric acid isolated from the ethanol extract of Gynura procumbens in promoting intestinal absorption of chlorogenic acid and reversing alcoholic fatty liver disease.

ETHNOPHARMACOLOGICAL RELEVANCE: Our previous studies found that the ethanol extract of Gynura procumbens (EEGS) reduced hepatic steatosis in alcoholic fatty liver disease (AFLD). AIM OF THE STUDY: To explore the active ingredients from EEGS and their relevant mechanism of action in alleviating alcoholic liver injuries. AIM OF THE STUDY: To explore the active ingredients from EEGS and their intestinal absorption characteristics as an approach for understanding mechanism of action in alleviating alcoholic liver injuries. MATERIALS AND METHODS: Monitored by high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC), chemical constituents from the prepared EEGS were isolated by means of solvent extraction, repeated column chromatography, preparative HPLC and other methods, and their structures were identified based on spectroscopic methods. The in vivo intestinal absorption rate of chlorogenic acid (CA), the active component of the EEGS, both in a single form and in the EEGS were monitored by the single-pass intestinal perfusion (SPIP) method in rats. The protective effect of EEGS and its active components on alcoholic liver injuries was evaluated in the alcoholic liver injury model of C57BL/6J male mice induced by Lieber-DeCarli alcohol liquid feed. RESULTS: Three noncaffeoyl quinic acid components were isolated and identified from the EEGS, namely, 3-trans-p-coumaroyl quinic acid (0.9%), 3-cis-p-coumaroyl quinic acid (2.7%), and trans-p-coumaric acid (0.6%). In vivo intestinal absorption of CA decreased with the increase of pH value of perfusion solution in the range of 5.5-7.8. The maximum absorption percentage of CA alone was 6.7 ± 2.4%, while the maximum absorption percentage of CA in the EEGS was 16.0 ± 2.2%, which was 2.4 times higher than that of CA alone. The results of animal experiments showed that the degree of fatty liver of mice treated with EEGS was significantly lower than that of the CA, trans-p-coumaric acid, and the combination group of CA and trans-p-coumaric acid alone. CONCLUSION: The above results indicated that trans-p-coumaric acid isolated from the dried stems of Gynura procumbens assisted CA being absorbed into the body and worked together with CA to improve the function of liver lipid metabolism, reduce hepatic lipid accumulation in a mouse model of AFLD and effectively counteract alcohol-induced fatty liver disease.

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.

TCQA, A Natural Caffeoylquinic Acid Derivative Attenuates H2O2-Induced Neuronal Apoptosis by Suppressing Phosphorylation of MAPKs Signaling Pathway.

1,3,5-Tri-O-caffeoyl quinic acid is a caffeoylquinic acid derivative isolated from the roots of Arctium lappa L. Our previous studies have revealed that the ethyl acetate extract of the roots of A. lappa L. and the caffeoylquinic acids contained in it possess antioxidant properties, especially 1,3,5-tri-O-caffeoyl quinic acid. The present study aimed to investigate the protective effects of 1,3,5-tri-O-caffeoyl quinic acid against hydrogen peroxide-induced oxidative stress and explore the underlying mechanism. We found that 1,3,5-tri-O-caffeoyl quinic acid prevented the decline of cell viability and excessive release of lactate dehydrogenase induced by hydrogen peroxide. In addition, Hoechst 33 342 staining and Annexin V-PI double staining showed that 1,3,5-tri-O-caffeoyl quinic acid inhibited hydrogen peroxide-induced neuronal cell apoptosis. 1,3,5-Tri-O-caffeoyl quinic acid reduced the excessive production of intracellular reactive oxygen species, decreased the malondialdehyde content, and improved the activity of superoxide dismutase. Furthermore, 1,3,5-tri-O-caffeoyl quinic acid restored the loss of mitochondrial membrane potential in SH-SY5Y cells induced by hydrogen peroxide. 1,3,5-Tri-O-caffeoyl quinic acid downregulated the overexpression of proapoptotic proteins, including Bax, cytochrome c, cleaved caspase-9, and cleaved caspase-3 as well as promoted the expression of the antiapoptotic protein Bcl-2. Moreover, the phosphorylation of mitogen-activated protein kinases induced by hydrogen peroxide was inhibited by 1,3,5-tri-O-caffeoyl quinic acid. Pretreatment with 1,3,5-tri-O-caffeoyl quinic acid also promoted the activation of phosphorylated Akt. Taken together, these findings suggest that 1,3,5-tri-O-caffeoyl quinic acid exerts protective effects against hydrogen peroxide-induced neuronal apoptosis. In addition, inhibition of the mitogen-activated protein kinase signaling pathway and the activation of Akt are implicated in the antioxidant activity of 1,3,5-tri-O-caffeoyl quinic acid, giving new insight in searching for a compound with antioxidant activity for the treatment of oxidative stress-associated neurological diseases.

Novel Quinic Acid Glycerates from Tussilago farfara Inhibit Polypeptide GalNAc-Transferase.

The discovery of a bioactive inhibitor tool for human polypeptide N-acetylgalactosaminyl transferases (GalNAc-Ts), the initiating enzyme for mucin-type O-glycosylation, remains challenging. In the present study, we identified an array of quinic acid derivatives, including four new glycerates (1-4) from Tussilago farfara, a traditional Chinese medicinal plant, as active inhibitors of GalNAc-T2 using a combined screening approach with a cell-based T2-specific sensor and purified enzyme assay. These inhibitors dose-dependently inhibited human GalNAc-T2 but did not affect O-linked N-acetylglucosamine transferase (OGT), the other type of glycosyltransferase. Importantly, they are not cytotoxic and retain inhibitory activity in cells lacking elongated O-glycans, which are eliminated by the CRISPR/Cas9 gene editing tool. A structure-activity relationship study unveiled a novel quinic acid-caffeic acid conjugate pharmacophore that directs inhibition. Overall, these new natural product inhibitors could serve as a basis for developing an inhibitor tool for GalNAc-T2.

Neochlorogenic Acid Attenuates Hepatic Lipid Accumulation and Inflammation via Regulating miR-34a In Vitro.

Neochlorogenic acid (5-Caffeoylquinic acid; 5-CQA), a major phenolic compound isolated from mulberry leaves, possesses anti-oxidative and anti-inflammatory effects. Although it modulates lipid metabolism, the molecular mechanism is unknown. Using an in-vitro model of nonalcoholic fatty liver disease (NAFLD) in which oleic acid (OA) induced lipid accumulation in HepG2 cells, we evaluated the alleviation effect of 5-CQA. We observed that 5-CQA improved OA-induced intracellular lipid accumulation by downregulating sterol regulatory element-binding protein 1 (SREBP1) and fatty acid synthase (FASN) expression, which regulates the fatty acid synthesis, as well as SREBP2 and HMG-CoA reductases (HMG-CoR) expressions, which regulate cholesterol synthesis. Treatment with 5-CQA also increased the expression of fatty acid ß-oxidation enzymes. Remarkably, 5-CQA attenuated OA-induced miR-34a expression. A transfection assay with an miR-34a mimic or miR-34a inhibitor revealed that miR-34a suppressed Moreover, Sirtuin 1 (SIRT1) expression and inactivated 5' adenosine monophosphate-activated protein kinase (AMPK). Our results suggest that 5-CQA alleviates lipid accumulation by downregulating miR-34a, leading to activation of the SIRT1/AMPK pathway.

Anti-Inflammatory Effect of 4,5-Dicaffeoylquinic Acid on RAW264.7 Cells and a Rat Model of Inflammation.

Anti-inflammatory agents that are safer and more effective than the currently used non-steroidal anti-inflammatory drugs are urgently needed. The dicaffeoylquinic acid (diCQA) isomer 4,5-diCQA exhibits antioxidant activity and various other health-promoting benefits; however, its anti-inflammatory properties require further investigation. This study was conducted to evaluate the anti-inflammatory properties of 4,5-diCQA in vitro and in vivo using RAW264.7 cells and a carrageenan-induced inflammation model, respectively. In RAW264.7 cells, 4,5-diCQA pretreatment significantly inhibited lipopolysaccharide-induced expression of nitric oxide, prostaglandin E2, nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-α, interleukin-1ß, and interleukin-6, without inducing cytotoxicity. The inhibitory effects of 4,5-diCQA were mediated by the suppression of nuclear factor-κB nuclear translocation and mitogen-activated protein kinase (MAPK) phosphorylation. Oral administration of 4,5-diCQA at doses of 5, 10, and 20 mg/kg of the body weight suppressed carrageenan-induced edema and the expression of nitric oxide synthase, cyclooxygenase-2, and tumor necrosis factor-α in a dose-dependent manner. Collectively, our results suggest that 4,5-diCQA exerts anti-inflammatory effects by suppressing activation of the nuclear factor-κB and MAPK pathways in vitro and reducing carrageenan-induced edema in vivo. Therefore, 4,5-diCQA shows potential as a natural alternative to non-steroidal anti-inflammatory drugs.

Neochlorogenic acid: an anti-HIV active compound identified by screening of Cortex Mori [Morus Alba L. (Moraceae)].

CONTEXT: Chinese herbs such as Cortex Mori [Morus alba L. (Moraceae)] may inhibit human immunodeficiency virus (HIV), but active compounds are unknown. OBJECTIVE: Screening of Cortex Mori and other herbs for anti-HIV active compounds. MATERIALS AND METHODS: HIV-1 virus (multiplicity of infection: 20), and herbs (dissolved in dimethyl sulfoxide, working concentrations: 10, 1, and 0.1 mg/mL) such as Cortex Mori, etc., were added to 786-O cells (105 cell/well). Zidovudine was used as a positive control. Cell survival and viral inhibition rates were measured. The herb that was the closest inactivity to zidovudine was screened. Mass spectrometry identified the active compounds in herbs (mobile phase: 0.05% formic acid aqueous solution and acetonitrile, gradient elution, detection wavelength: 210 nm). The effect of the compounds on reverse transcriptase (RT) products were evaluated by real-time PCR. Gene enrichment was used to analyse underlying mechanisms. RESULTS: With a dose of 1 mg/mL of Cortex Mori, the cell survival rate (57.94%) and viral inhibition rate (74.95%) were closest to the effect of zidovudine (87.87%, 79.81%, respectively). Neochlorogenic acid, one of the active ingredients, was identified by mass spectrometry in Cortex Mori. PCR discovery total RT products of neochlorogenic acid group (mean relative gene expression: 6.01) significantly inhibited (control: 35.42, p < 0.0001). Enrichment analysis showed that neochlorogenic acid may act on haemopoietic cell kinase, epidermal growth factor receptor, sarcoma, etc., thus inhibiting HIV-1 infection. CONCLUSIONS: For people of low socioeconomic status affected by HIV, Chinese medicine (such as Cortex Mori) has many advantages: it is inexpensive and does not easily produce resistance. Drugs based on active ingredients may be developed and could have important value.

Salicinoyl Quinic Acids and Their Prostaglandin E2 Production Inhibitory Activities from the Fruits of Casearia grewiifolia.

Phytochemical investigation on the dried fruits of Casearia grewiifolia led to the identification of 10 new salicinoyl quinic acid derivatives (1-10), a new benzoyl quinic acid (11), and two known compounds (12 and 13). The structures of the new compounds were elucidated by interpreting 1D and 2D NMR spectroscopic data including HMBC and EXSIDE along with a chemical method for sugar unit analysis. All isolates were evaluated for their inhibitory activities against prostaglandin E2 (PGE2) production in ultraviolet B (UVB)-irradiated HaCat keratinocytes. Of the isolates tested, compounds 6 and 12 were found to inhibit PGE2 production with IC50 values of 20.5 and 28.8 µM, respectively.

A promising strategy for investigating the anti-aging effect of natural compounds: a case study of caffeoylquinic acids.

Caffeoylquinic acids, as plant-derived polyphenols, exhibit multiple biological activities such as antioxidant, anti-inflammatory, and neuroprotective activities. However, only limited information about their effect on longevity is available. In the current study, molecular docking was employed to explore the interactions between six representative caffeoylquinic acids and the insulin-like growth factor-1 receptor (IGFR), which is an important target protein for longevity. The results indicated that all six compounds were embedded well in the active pocket of IGFR, and that 3,5-diCQA exhibited the strongest affinity to IGFR. Moreover, ASP1153, GLU1080, ASP1086, and ARG1003 were the key amino acid residues during the interaction of these 6 compounds with IGFR. Furthermore, the lifespan extension effect of caffeoylquinic acids was evaluated in a Caenorhabditis elegans (C. elegans) model. The results revealed that all the caffeoylquinic acids significantly extended the lifespan of wild-type worms, of which 3,5-diCQA was the most potent compound. Meanwhile, 3,5-diCQA enhanced the healthspan by increasing the body bending and pharyngeal pumping rates and reducing the intestinal lipofuscin level. Further studies demonstrated that 3,5-diCQA induced longevity effects by downregulating the insulin/insulin-like growth factor signaling (IIS) pathway. This study suggested that the combination of molecular docking and genetic analysis of specific worm mutants could be a promising strategy to reveal the anti-aging mechanisms of small molecule natural compounds.

Insights into cyclooxygenase-2 inhibition by isolated bioactive compounds 3-caffeoyl-4-dihydrocaffeoyl quinic acid and isorhamnetin 3-O-ß-D-glucopyranoside from Salicornia herbacea.

BACKGROUND: Cyclooxygenase-2 (COX-2) is an important enzyme with numerous biological functions. Overexpression of COX-2 has been associated with various inflammatory-related diseases and therefore, projected as an important pharmacological target. PURPOSE: We aimed to investigate the inhibitory potential of isolated bioactive compounds, 3-caffeoyl-4-dihydrocaffeoyl quinic acid (CDQ) and isorhamnetin 3-O-ß-d-glucopyranoside (IDG), from Salicornia herbacea against COX-2 using both computational and in vitro approaches. METHODS: Computational analysis, including molecular docking, molecular dynamics (MD) simulations, and post-simulations analysis, were employed to estimate the binding affinity and stability of CDQ and IDG in the catalytic pocket of COX-2 against Celecoxib as positive control. These predictions were further evaluated using in vitro enzyme inhibition as well as gene expression mediation in macrophages cells. RESULTS: Molecular docking analysis revealed substantial binding energy of CDQ (-6.1 kcal/mol) and IDG (-5.9 kcal/mol) with COX-2, which are lower than Celecoxib (-8.1 kcal/mol). MD simulations (100 ns) and post simulation analysis exhibited the substantial stability and binding affinity of docked CDQ and IDG compounds with COX-2. In vitro assays indicated significant COX-2 inhibition by CDQ (IC50 = 76.91 ± 2.33 µM) and IDG (IC50 = 126.06 ± 9.44 µM). This result supported the inhibitory potential of isolated bioactive compounds against COX-2. Also, a cellular level study revealed a downregulation of COX-2 expression in tumor necrosis factor-alpha stimulated RAW 264.7 macrophages treated with CDQ and IDG. CONCLUSION: Computational and experimental analysis of CDQ and IDG from S. herbacea established their potential in the inhibition and mediation of COX-2. Hence, CDQ and IDG can be considered for therapeutic development against COX-2 linked disorders, such as inflammation and cancer. Furthermore, CDQ and IDG structures can be served as a lead compound for the development of advanced novel anti-inflammatory drugs.