Microarray meta-analysis reveals comprehensive effects of 3,4,5-tricaffeolyquinic acid in cell differentiation and signaling

Caffeoylquinic acids (CQA) are polyphenolic compounds found in fruits, vegetables, coffee, and spices that have exhibited several beneficial activities, including antioxidant, antibacterial, neuroprotective, anti-inflammatory, anticancer, antiviral, antidiabetic, and cardiovascular effects. A derivative, TCQA (3,4,5-Tri-O-caffeoylquinic acid), has also shown both neurogenic and pigment differentiation potential. A transcriptomic-based meta-analysis was conducted to explore potential biochemical processes and molecular targets of TCQA. This approach involved integrating data from various cell and tissue types, including human amniotic stem cells, human neural stem cells, human dermal papilla cells, and the brain cortex of aging model mice. It offered a comprehensive perspective on the significant gene regulations in response to TCQA treatment. The objective was to uncover the mechanism and novel targets of TCQA, facilitating a further understanding of its functions. New areas of interest found were TCQA's effect on adipogenesis, heart, and muscle tissue development. In addition, significantly enhanced biological activities found through meta-analysis included cell cycle, VEGFA-VEGFR2 pathway, and BMP signaling. Overall, a comprehensive functional and visual analysis using available biological databases uncovered the multi-target potential of this natural compound.

Effects of caffeoylquinic acid analogs derived from aerial parts of Artemisia iwayomogi on adipogenesis

Artemisia iwayomogi (AI) is a perennial herb found in Korea. Its ground parts are dried and used in food and traditional medicine for treating hepatitis, inflammation, cholelithiasis, and jaundice. In this study, the anti-obesity effects of single compounds isolated from AI extracts on adipose tissue were investigated. Results demonstrated that caffeoylquinic acid analogs strongly inhibited adipocyte differentiation from 3T3-L1 preadipocytes and reduced neutral lipids in differentiated adipocytes. Accordingly, lipid accumulation in adipocytes decreased, and lipid droplets became granulated. Caffeoylquinic acid analogs suppressed the expression of adipocyte differentiation marker genes, namely, Cebpa, Lep, and Fabp4, but it induced the expression of Ucp1, Ppargc1a, and Fgf21, which are browning biomarkers. Therefore, caffeoylquinic acid analogs from AI inhibited preadipocyte differentiation and induced adipose tissue browning, suggesting that these compounds could be promising therapeutic agents for obesity.

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.

Ethanol supernatant extracts of Gynura procumbens could treat nanodiethylnitrosamine-induced mouse liver cancer by interfering with inflammatory factors for the tumor microenvironment

ETHNOPHARMACOLOGICAL RELEVANCE

Gynura procumbens (Lour.) Merr, (Family Asteraceae), which serves as both medicine and food in traditional ethnic medicine, has the effects of diminishing inflammation, relieving cough, reducing blood glucose and lipids levels, mitigating hepatotoxicity, and can be used for liver cancer prevention and treatment.

AIM OF THE STUDY

To explore how the ethanol extract of Gynura procumbens stems (EEGS) can effectively intervene in the tumor microenvironment, it is necessary to study the mechanism of EEGS on the chemical toxicant nanodiethylnitrosamine (nanoDEN) that induces liver cancer.

MATERIALS AND METHODS

EEGS contains large quantities of caffeoylquinic acid (CAC) and non-caffeoylquinic acid (n-CAC), which can be separated by high-performance liquid chromatography. The liver cancer model that was induced by the chemical toxin, nanoDEN, was used to clarify the effective mechanism for tumor intervention of the EEGS and its active ingredients.

RESULTS

(1) after interventions with the four drugs on liver cancer, the tumor nodules were obviously reduced and inflammation levels improved. (2) The immunohistochemical staining results showed that both the EEGS and its active ingredients could significantly reverse the abnormal changes in inflammation, proliferation, aging and hypoxia-related proteins in mouse liver tissues that were caused by nanoDEN. (3) Real-time PCR results showed that compared with the nanoDEN group, the expression levels of inflammatory, fatty, and fibrosis-related factors in each group after drug intervention were decreased. (4) The transmission electron microscopy measurements showed that the EEGS significantly reversed the nanostructure changes in hepatocytes that were induced by nanoDEN.

CONCLUSION

The EEGS component of Gynura procumbens is effective in preventing and treating liver cancer by interfering with the inflammatory microenvironment during oncogenesis induced by nanoDEN.

Ultrasonic degradation kinetics and isomerization of 3- and 4-O-caffeoylquinic acid at various pH: The protective effects of ascorbic acid and epigallocatechin gallate on their stability

Caffeoylquinic acids are existed in many plant species with various biological and pharmacological activities. 3-O-caffeoylquinic acid and 4-O-caffeoylquinic acid are two isomers of caffeoylquinic acids, which may be degraded and transformed to their isomers in processing. The present paper found that the stability of 3- and 4-O-caffeoylquinic acid had decreased with the increasing solution alkalinity. 3-O-caffeoylquinic acid was more stable than 4-O-caffeoylquinic acid at the same condition. During degradation, 3- and 4-O-caffeoylquinic acid were partially converted to their isomers. Additionally, ultrasonic effects on the degradation and isomerization of 3- and 4-O-caffeoylquinic acid at different pH were studied. Ultrasound facilitated the degradation and isomerization of these compounds. The degradation kinetics were described by the Weibull equation. The protective effect of ascorbic acid and epigallocatechin gallate were also explored. Ascorbic acid and epigallocatechin gallate could alleviate the degradation of 3- and 4-O-caffeoylquinic acid under certain conditions.

Tomato leaves under stress: a comparison of stress response to mild abiotic stress between a cultivated and a wild tomato species

Tomato is one of the most produced crop plants on earth and growing in the fields and greenhouses all over the world. Breeding with known traits of wild species can enhance stress tolerance of cultivated crops. In this study, we investigated responses of the transcriptome as well as primary and secondary metabolites in leaves of a cultivated and a wild tomato to several abiotic stresses such as nitrogen deficiency, chilling or warmer temperatures, elevated light intensities and combinations thereof. The wild species responded different to varied temperature conditions compared to the cultivated tomato. Nitrogen deficiency caused the strongest responses and induced in particular the secondary metabolism in both species but to much higher extent in the cultivated tomato. Our study supports the potential of a targeted induction of valuable secondary metabolites in green residues of horticultural production, that will otherwise only be composted after fruit harvest. In particular, the cultivated tomato showed a strong induction in the group of mono caffeoylquinic acids in response to nitrogen deficiency. In addition, the observed differences in stress responses between cultivated and wild tomato can lead to new breeding targets for better stress tolerance.

Effect of gamma irradiation on the caffeoylquinic acid derivatives content, antioxidant activity, and microbial contamination of Pluchea indica leaves

Pluchea indica (L.) Less. leaf has a long history of being used as a food and in traditional medicines. Although gamma irradiation is an effective decontamination method, it must be performed appropriately to preserve the bioactive constituents and biological activities of the plant. This study investigated the influence of gamma irradiation on the caffeoylquinic acid derivatives content, antioxidant capacity, and microbial burden of P. indica leaf. Dried P. indica leaf powder was exposed to gamma rays from cobalt-60 at the absorbed doses of 2.5, 5.0, 7.5, and 10 kGy. After a maceration of P. indica leaf with 70% ethanol, the content of six caffeoylquinic acid derivatives (CQAs) in the extract was assayed using high-performance liquid chromatography. The antioxidant capacity of the ethanolic extract was also determined using the DPPH, ABTS, and ferric reducing antioxidant power (FRAP) methods. The total aerobic bacteria and total yeast and mold counts were investigated using the Petrifilm method at 0 and 3 months after irradiation. Doses of 5–10 kGy significantly increased the CQA level (P < 0.05). The antioxidant activity was enhanced significantly at 2.5–10 kGy (P < 0.05). Doses of 2.5–10 kGy also effectively reduced the microbial load (P < 0.05). Among the irradiation doses, 10 kGy showed the best results. Thus, gamma irradiation at 10 kGy is useful in increasing CQA content and antioxidant capacity as well as reducing the microbial load of P. indica leaf.

Burdock (Arctium lappa L) roots as a source of inulin-type fructans and other bioactive compounds: Current knowledge and future perspectives for food and non-food applications

The roots and tubers of the Asteraceae family are known as a source of various oligosaccharides, and chicory roots and Jerusalem artichoke have stood out for its commercial viability. However burdock root (Arctium lappa L.), which is adapted to temperate climate, moist, and sandy soil, is still unknown as health food in the western world. This review showed the potential of burdock roots as a source of prebiotic fibers, chlorogenic acids, cinnarine, lignans, and quercetin. The extraction methods of burdock functional compounds are made with water, temperature and time variations only. Biological assays showed antioxidant activity, anti-inflammatory, and hypolipidemic properties, and gastric mucosal defense mechanisms, among others. Therefore, the use of burdock roots as functional food should be encouraged in countries that have imported products derived from other roots of the same family for health benefits.

Metabolite profiles of Pulicaria crispa and P. incisa in relation to their in-vitro/ in-vivo antioxidant activity and hepatoprotective effect: A comparative mass spectrometry-based metabolomics

Plants of the genus Pulicaria (family: Asteraceae) are widely used in central Asia and the Middle East for treatment of different human diseases. Ultra performance liquid chromatography coupled to high resolution mass spectrometry (UPLC/MS) was utilized to establish the metabolic profiles of two Pulicaria species: P. crispa and P. incisa. 122 metabolites were identified including flavonoids (37), phenolic acids (22), sesquiterpenes (17), diterpenes (7), and fatty acids (27), with enrichment in methoxylated flavonoids (20), caffeoylquinic acid conjugates (14) xanthane sesquiterpenes (9) and hydroxylated fatty acids (20) in both Pulicaria species. The metabolite profile of P. incisa was characterized by the presence of tri- and tetra-methoxylated flavonoids while xanthane sesquiterpenes were the main chemical markers of P. crispa. Additionally, a novel sesquiterpene acid (dihydropulicaric acid) was annotated in both species based on its MS fragments. Antioxidant activity for P. crispa and P. incisa methanol extracts was assessed in vitro based on DPPH and ABTS assays and further in vivo using chlorpromazine intoxicated rat model. Results revealed that P. incisa extract was more effective in inhibiting both DPPH and ABTS free radicals (IC₅₀ 0.36 and 0.52 mg/mL, respectively) than P. crispa (IC₅₀ 0.51 and 0.73 mg/mL). In the animal model, antioxidant activity of P. incisa (20 mg/kg/day) was also slightly higher causing a 55 % reduction in MDA levels and 65 % increase in GSH activity compared to untreated animals. Furthermore, both extracts showed a hepatoprotective effect as revealed by improvement in levels of serum biomarkers of liver functions: total bilirubin, alanine transaminase (ALT) and aspartate transaminase (AST) comparable to silymarin at 25 mg/kg/day. These findings were also supported by the preserved integrity of the hepatic tissues of animals receiving either extracts at a dose of 20 mg/kg b.wt. The present study reveals for the potential antioxidant and hepatoprotective effects for Pulicaria in relation to its bioactive metabolites.

Don

Background and purpose:

Dorema ammoniacum D. Don (Apiaceae family) is a perennial plant whose oleo- gum resin is used as a natural remedy for various diseases, especially chronic bronchitis, and asthma. In the present study, hydromethanolic extract of D. ammoniacum root was subjected to phytochemical analyses and α-glucosidase inhibitory potentials of the isolated compounds were assessed.

Experimental approach:

Silica gel (normal and reversed phases) and Sephadex^® LH-20 column chromatographies were used for the isolation and purification of the compounds. Structures of the compounds were characterized by 1D and 2D nuclear magnetic resonance (NMR) techniques. All the isolated compounds were assessed for their in vitro α-glucosidase inhibitory activity in comparison with acarbose, a standard drug.

Findings/Results:

Two phloroacetophenone glycosides; echisoside (1) and pleoside (2), along with dihydroferulic acid-4-O-β-D-glucopyranoside (3), and β-resorcylic acid (4), and two caffeoylquinic acid derivatives; chlorogenic acid (5) and 1, 5-dicaffeoylquinic acid (cynarin, 6) were isolated. Among the isolated compounds, the α-glucosidase inhibitory effect of 1,5-dicaffeoylquinic acid was found as 76.9% of the acarbose activity at 750 μM (IC₅₀ value of acarbose).

Conclusion and implications:

Considerable α-glucosidase inhibitory effect of 1,5-dicaffeoylquinic acid makes it an appropriate candidate for further studies in the development of new natural antidiabetic drugs.

Seasonal variation in bioactive properties and phenolic composition of cardoon (Cynara cardunculus var. altilis) bracts

Cardoon (Cynara cardunculus L.) bracts were collected at different maturation stages to investigate seasonal changes in the phenolic compounds profile and in vitro bioactivities. Among the 12 phenolic compounds tentatively identified, 3,5-O-dicaffeoylquinic acid (21.83 mg/g extract) and apigenin-7-O-glucuronide (10.6 mg/g extract) were the most abundant. Immature bracts (C1: principal growth stage (PGS) 5) had the highest phenolic compounds content, and anti-inflammatory (IC₅₀ = 72 µg/mL) and cytotoxic (GI₅₀ of 30-79 µg/mL) activities. Moreover, extract C1 inhibited efficiently the formation of thiobarbituric acid reactive substances (TBARS; IC₅₀ = 26.8 µg/mL), while extract C8 (PGS 8/9) was more effective against oxidative haemolysis (IC₅₀ 38 and 75 µg/mL). The highest antibacterial and antifungal activities were attributed to samples C1 and C6 (PGS 7/8) and samples C2 (PGS 5/6) and C4 (PGS 6/7), respectively. Overall, the obtained results suggest the seasonal changes of polyphenolic composition and bioactivity of cardoon bracts of variable maturity.

Cell Cycle Arrest and Apoptosis Induction of Phloroacetophenone Glycosides and Caffeoylquinic Acid Derivatives in Gastric Adenocarcinoma (AGS) Cells

INTRODUCTION

In the present study, we analyzed anti-proliferative and apoptosis induction activity of five phenolic compounds: echisoside, pleoside, chlorogenic acid, 4,5-Di-O-caffeoylquinic acid, and cynarin on AGS (adenocarcinoma gastric) cell line.

METHOD

These phenolic compounds were isolated from methanol extract of Dorema glabrum root. An MTT assay was conducted to evaluate the inhibitory effect on cancer cells. EB/AO staining was done to assess the mode of cell death and morphological changes of the cells' nuclei. Cell cycle distribution of the cells was analyzed by flow cytometry, and for further confirmation of the pathway, mRNA levels of apoptosis cascade players were quantified by qRT-PCR.

RESULT

We found that echisoside, pleoside, chlorogenic acid, 4,5-Di-O-caffeoylquinic acid, and cynarin inhibited the proliferation of AGS cancer cells in vitro. Our data revealed that these compounds triggered morphological changes characteristic of apoptotic cell death. These compounds up-regulated bax and caspase3 expression and down-regulated cyclin D1, bcl2, VEGFA, c-myc and survivin. Moreover, cell population increased at the G1 phase, and a number of cells at the G2/M phase of the cell cycle decreased after treatment.

CONCLUSION

All these data suggest that phenolic compounds have a cytotoxic effect on gastric cancer cells and could trigger apoptosis. Besides cytotoxic activity, they could potentially arrest the cell cycle at the G1 phase.

Treatment with MQA, a Derivative of Caffeoylquinic Acid, Provides Neuroprotective Effects against Cerebral Ischemia Through Suppression of the p38 Pathway and Oxidative Stress in Rats

1,5-O-dicaffeoyl-3-O-(4-malic acid methylester)-quinic acid (MQA), extracted from Arctium lappa L., has been observed to exert neuroprotective effects in vitro. The aim of this study was to investigate whether MQA is an effective therapeutic method for cerebral ischemic injury in vivo. In this study, adult male rats were randomly divided into four groups: a normal group, a model group subjected to middle cerebral artery occlusion (MCAO) for 24 h, a model + MQA group (which received intragastric MQA for the 7 days prior to MCAO), and a model + positive drug group. MQA appeared to induce effects in cerebral ischemic injury in rats, by downregulating malondialdehyde, glutathione peroxidase, and nitric oxide synthase levels. Treatment with MQA significantly reduced infarcted sections. In addition, caspase-3 and Iba1 protein expression were evaluated with immunohistochemistry, and cortical cell apoptosis was assessed with terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assays. Expression of AKT and Bax, ERK1/2, P38 and Bcl-2, NFkB₁, PARP, and caspase-3 was assessed with Western blotting. We found Bcl-2 and NFkB₁ (p₅₀) expressions were upregulated, whereas the expression of PARP, caspase-3, NFkB₁ (p₁₀₅), ERK1/2, P38, AKT, and Bax was downregulated. In conclusion, we observed MQA was an effective treatment for cerebral ischemic injury in rats.

Identification of caffeoylquinic acid derivatives as natural protein tyrosine phosphatase 1B inhibitors from Artemisia princeps

Considerable attention has been paid to protein tyrosine phosphatase 1B (PTP1B) inhibitors as a potential therapy for diabetes, obesity, and cancer. Ten caffeoylquinic acid derivatives (1-10) from leaves of Artemisia princeps Pamp. (Asteraceae) were identified as natural PTP1B inhibitors. Among them, chlorogenic acid (3) showed the most potent inhibitory activity (IC₅₀ 11.1 μM). Compound 3 was demonstrated to be a noncompetitive inhibitor by a kinetic analysis. Molecular docking simulation suggested that compound 3 bound to the allosteric site of PTP1B. Furthermore, compound 3 showed remarkable selectivity against four homologous PTPs. According to these findings, compound 3 might be potentially valuable for further drug development.

The Pocket-4-Life project, bioavailability and beneficial properties of the bioactive compounds of espresso coffee and cocoa-based confectionery containing coffee: study protocol for a randomized cross-over trial

Background

Coffee is an important source of bioactive compounds, including caffeine, phenolic compounds (mainly chlorogenic acids), trigonelline, and diterpenes. Several studies have highlighted the preventive effects of coffee consumption on major cardiometabolic diseases, but the impact of coffee dosage on markers of cardiometabolic risk is not well understood. Moreover, the pool of coffee-derived circulating metabolites and the contribution of each metabolite to disease prevention still need to be evaluated in real-life settings. The aim of this study will be to define the bioavailability and beneficial properties of coffee bioactive compounds on the basis of different levels of consumption, by using an innovative experimental design. The contribution of cocoa-based products containing coffee to the pool of circulating metabolites and their putative bioactivity will also be investigated.

Methods

A three-arm, crossover, randomized trial will be conducted. Twenty-one volunteers will be randomly assigned to consume three treatments in a random order for 1 month: 1 cup of espresso coffee/day, 3 cups of espresso coffee/day, and 1 cup of espresso coffee plus 2 cocoa-based products containing coffee twice per day. The last day of each treatment, blood and urine samples will be collected at specific time points, up to 24 hours following the consumption of the first product. At the end of each treatment the same protocol will be repeated, switching the allocation group. Besides the bioavailability of the coffee/cocoa bioactive compounds, the effect of the coffee/cocoa consumption on several cardiometabolic risk factors (anthropometric measures, blood pressure, inflammatory markers, trimethylamine N-oxide, nitric oxide, blood lipids, fasting indices of glucose/insulin metabolism, DNA damage, eicosanoids, and nutri-metabolomics) will be investigated.

Discussion

Results will provide information on the bioavailability of the main groups of phytochemicals in coffee and on their modulation by the level of consumption. Findings will also show the circulating metabolites and their bioactivity when coffee consumption is substituted with the intake of cocoa-based products containing coffee. Finally, the effect of different levels of 1-month coffee consumption on cardiometabolic risk factors will be elucidated, likely providing additional insights on the role of coffee in the protection against chronic diseases.

Trial registration

ClinicalTrials.gov, NCT03166540. Registered on May 21, 2017.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2271-2) contains supplementary material, which is available to authorized users.

Caffeoylquinic Acid Enhances Proliferation of Oligodendrocyte Precursor Cells

This report evaluates the protective effect of caffeoylquinic acid (CA) injury to oligodendrocyte precursor cells (OPCs) by promoting the formation of oligodendrocytes. Neonatal rat brain was used to isolate primary OPCs and non-lethal CoCl2 was used to induce hypoxic stress to inhibit the differentiation of OPCs. Differentiation of OPCs was estimated by survival assay and the expressions of myelin-basic-protein (MBP). Moreover, the effect of CA on the Akt signanling pathway was also estimated in the presence and absence of LY294002 (PI3K/Akt inhibitor) and adrenomedullin (AM) receptor antagonist (AM22-52) by using western blot assay. It was observed that CA enhances the differentiation OPCs in CoCl2 induced hypoxic stress condition. However treatment with CA in presence of LY294002 and AM22-52 was not able to enhance the differentiation of OPCs. Moreover treatment with CA significantly enhances the phosphorylation of Akt and presence of LY294002 and AM22-52 inhibits it. This report concludes that CA effectively attenuates the injury of white matter (OPCs) by enhancing the differentiation of OPCs. It enhances the formation of oligodendrocytes by activating AM receptor and thereby accelerates the regeneration of neuron in pathological condition.

Phenolic composition, antioxidant activity and mineral profile in two seed-propagated artichoke cultivars as affected by microbial inoculants and planting time

The aim of this study was to assess the mineral composition, antioxidant activity, total phenolics and target polyphenols of two-seed propagated artichoke cultivars 'Romolo' and 'Istar' in relation to planting time (September and October), and seed coating with a consortium of arbuscular mycorrhizal fungi and Trichoderma atroviride (coated and uncoated seeds during the second planting time). 'Romolo' was found to be richest in K⁺, Ca²⁺ and Mg²⁺. Planting artichoke in October suppressed the antioxidant capacity (DPPH and ABTS) compared to the first planting period. The greatest accumulation of 3-O-caffeoylquinic acid, 5-O-caffeoylquinic acid and 1,3-di-O-caffeoylquinic acid in primary heads occurred in 'Romolo' during the first planting time. The content of 3-O-caffeoylquinic acid, 5-O-caffeoylquinic acid, apigenin 7-O-glucuronide in primary heads as well 1,5-di-O-caffeoylquinic acid in secondary heads increased with seed coating especially in 'Romolo'. These findings can assist growers in selecting cultivars and agronomical practices combining optimal yield with high nutraceutical properties.

Caffeoylquinic Acid Derivatives Protect SH-SY5Y Neuroblastoma Cells from Hydrogen Peroxide-Induced Injury Through Modulating Oxidative Status

Oxidative stress has been confirmed as a contribution to the pathogenesis and pathophysiology of many neurological disorders such as Alzheimer's disease and Parkinson's disease. Caffeoylquinic acids (CQAs) are considered to have anti-oxidative stress ability in a previous study, but the structure-activity relationships (SARs) of CQAs in neuroprotective effects are still unclear. In the present study, we primarily expound the SARs of CQAs in counteracting H₂O₂-induced injury in SH-SY5Y cells. We found that CQAs (1-10) represented the protection of SH-SY5Y cells against H₂O₂-induced injury in varying degrees and malonyl groups could obviously increase the anti-oxidative stress ability of CQAs. Intensive studies of 4,5-O-dicaffeoyl-1-O-(malic acid methyl ester)-quinic acid (MDCQA) indicated that the mechanisms could potentially involve activation of endogenous antioxidant enzymes and the regulation of the phosphorylation of MAPKs and AKT. In conclusion, MDCQA could serve as a neuroprotective agent with a potential to attenuate oxidative stress.

Compound MQA, a Caffeoylquinic Acid Derivative, Protects Against NMDA-Induced Neurotoxicity and Potential Mechanisms In Vitro

AIMS

Compound MQA (1,5-O-dicaffeoyl-3-O-[4-malic acid methyl ester]-quinic acid) is a natural derivative of caffeoylquinic acid isolated from Arctium lappa L. roots. However, we know little about the effects of MQA on the central nervous system. This study aims to investigate the neuroprotective effects and underlying mechanisms of MQA against the neurotoxicity of N-methyl-d-aspartate (NMDA).

METHODS AND RESULTS

Pretreatment with MQA attenuated the loss of cell viability after SH-SY5Y cells treated with 1 mM NMDA for 30 min by MTT assay. Hoechst 33342 and Annexin V-PI double staining showed that MQA inhibited NMDA-induced apoptosis. In addition to preventing Ca(2+) influx, the potential mechanisms are associated with increases in the Bcl-2/Bax ratio, attenuation of cytochrome c release, caspase-3, caspase-9 activities, and expressions. Also, MQA inhibited NMDA-induced phosphorylation of ERK1/2, p38, and JNK1/2. Furthermore, deactivation of CREB, AKT, and GSK-3β, upregulation of GluN2B-containing NMDA receptors (NMDARs), and downregulation of GluN2A-containing NMDARs were significantly reversed by MQA treatment. Computational docking simulation indicates that MQA possesses a well affinity for NMDARs.

CONCLUSION

The protective effects of MQA against NMDA-induced cell injury may be mediated by blocking NMDARs. The potential mechanisms are related with mitochondrial apoptosis, ERK-CREB, AKT/GSK-3β, p38, and JNK1/2 pathway.

Phytochemical and Antioxidant Investigation of the Aerial Parts of Dorema glabrum Fisch. & C.A. Mey

Dorema glabrum Fisch. & C.A. Mey. (Apiaceae) is a monocarpic perennial plant distributed in southern Caucasus. In Azerbaijan Republic folk medicine, the gum-resin of this species is used as a diuretic and anti-diarrheal agent. It is also traditionally used for the treatment of bronchitis and catarrh. In the present study, chemical constituents of the essential oil and extract of D. glabrum aerial parts were investigated and their free radical scavenging potentials were assessed. GC-MS and GC-FID analyses of the plant essential oil resulted in identifying twenty compounds, out of which elemicin (38.6%) and myristicin (14.3%) were main compounds. Seven compounds including daucosterol (1), chlorogenic acid (2), a mixture of cynarin (3) and 3,5-di-O-caffeoylquinic acid (4), isorhamnetin-3-O-β-D-glucopyranoside (5), isoquercetin (6) and astragalin (7) were also isolated from the ethyl acetate and methanol fractions of D. glabrum aerial parts using different chromatographic methods on silica gel (normal and reversed-phase) and sephadex LH20. Structures of the isolated compounds were elucidated using UV and (1)H, (13)C-NMR spectrain comparison with those reported in respective published data. Antioxidant activities of the crude extract, fractions and isolated compounds were evaluated using DPPH free radical scavenging assay method. Among the fractions, methanol fraction (IC50=53.3 ±4.7μg mL(-1)) and among the isolated compounds, caffeoylquinic acid derivatives exhibited the highest free radical scavenging activity (IC50= 2.2-2.6 μg mL(-1)).

The caffeoylquinic acid-rich Pandanus tectorius fruit extract increases insulin sensitivity and regulates hepatic glucose and lipid metabolism in diabetic db/db mice

Caffeoylquinic acids (CQAs) are widely distributed in various foods. While some CQAs have been shown to possess antihyperglycemic activities, whether it is beneficial for diabetes patients to ingest CQA-rich foods has still to be known. In this work, the antihyperglycemic and antihyperlipidemic effects of CQA-rich Pandanus tectorius fruit extract (PTF) was investigated in diabetic db/db mice. Treatment with PTF (200 mg/kg) significantly decreased body weight and fasting glucose level, alleviated hyperinsulinism and hyperlipidemia and declined glucose area under the curve in oral glucose tolerance test and insulin tolerance test. The elevated levels of serum proinflammatory cytokines and islet hypertrophy in db/db mice were remarkably attenuated by PTF treatment. Biochemical analysis showed that administration of PTF significantly stimulated the phosphorylation of AMP-activated protein kinase (AMPK) and Akt substract of 160 kDa (AS160), and enhanced the expression and translocation of glucose transporter type 4 (GLUT4) in skeletal muscles. It also increased the activity of hexokinase, decreased the expression of glucose 6-phosphatase and phosphoenolpyruvate carboxykinase and switched the transcription of several key lipid metabolic genes in the liver, which, in turn, improved hepatic glucose and lipid profiles as determined by nuclear magnetic resonance-based metabolomics. Overall, the CQA-rich PTF is beneficial for the treatment of diabetes. It may alleviate hyperglycemia and dyslipidemia via activation of AMPK-AS160-GLUT4 pathway in skeletal muscles and inhibition of gluconeogenesis and lipogenesis in the liver.