Singlet oxygen quenching and the redox properties of hydroxycinnamic acids

Evaluation of the anticancer effects of hydroxycinnamic acid isomers on breast cancer stem cells

Research on breast cancer stem cells (BCSCs) is crucial for improving our understanding of their roles in tumor resistance, metastasis, and relapse. This study investigated the anti-cancer effects of two isomers of hydroxycinnamic acids (HCA): para-coumaric acid (PCA) and ortho-coumaric acid (OCA) on breast cancer stem cells (BCSCs). The isolated and characterized stem cells contained CD44 + /CD24 surface markers, exhibited high levels of aldehyde dehydrogenase activity, and were able to form mammospheres. The evaluation of HCAs on stem cell proliferation, cell cycle, and apoptosis was conducted by comparing them with MCF-7, the luminal breast cancer cell line. The viability and immunoblot analyses demonstrated that HCA applications resulted in a dose-dependent decrease in the number of viable cells and inhibited phosphorylation of Extracellular regulated kinases 1/2 (ERK1/2). These findings were supported by the detection of suppressed colony formation and delayed wound-healing in HCA-exposed cells. E-cadherin expression increased in OCA-treated cells. Additionally, the arrest of G1/S phase progression and the downregulation of Cyclin D1 expression exhibited that OCA and PCA-induced cytostatic effects in BSCS cells. After treatment, the increased Annexin-V/7-AAD staining, along with elevated expression of caspase-3/7 and a decreased Bcl-2/Bax ratio, indicated apoptosis mediated by the activation of Janus kinase (JNK) and p38 Mitogen-activated kinase (p38 MAPK). In conclusion, both OCA and PCA exhibit anti-carcinogenic potential on BCSCs; However, OCA has a stronger effect and is becoming a promising candidate for further research.

Effects of Folic Acid and Caffeic Acid on Indirect Photo-oxidation of Proteins and Their Costabilization under Irradiation

Proteins, vitamins, and phenols are often present together in foods, but they are sensitive to environmental factors. Folic acid (FA), a synthetic form of folate, decomposes under light, leading to protein oxidation. Caffeic acid (CA), a phenolic acid, exhibits remarkable activity for scavenging reactive molecules. The exploitation of their interactions offers opportunities for designing the stabilizing system. In this study, FA-photodecomposition-induced protein (β-lactoglobulin, α-lactalbumin, bovine serum albumin, and β-casein) damage and its inhibition by CA were investigated in terms of protein composition and structural change. The results indicated that FA photoproducts oxidized the proteins via the electron transfer pathway, leading to degradation, aggregation, and unfolding. At the same time, photostability of FA, CA, and proteins in the tertiary mixture was better than that of any individual components. The antioxidant activity of the proteins contributed to their protection for FA. CA and its products inhibited FA photodecomposition and the photodecomposition-induced protein oxidation by trapping excited states.

Strawberry pollen as a source of UV-B protection ingredients for the phytoseiid mite Neoseiulus californicus (Acari: Phytoseiidae)

BACKGROUND

A new physical control method using ultraviolet-B (UV-B) lamps and light-reflecting sheets (UV method) significantly suppressed a spider mite population on greenhouse strawberries. Although UV-B radiation may adversely affect the survival of phytoseiid mites, previous research has suggested that Neoseiulus californicus can improve its survival on exposure to UV-B irradiation by consuming antioxidants contained in tea and peach pollen. In this study, we evaluated strawberry pollen as an alternative food source for N. californicus and examined whether antioxidants in the pollen mitigated UV-B damage to N. californicus.

RESULTS

The fecundity of N. californicus females reared on Tetranychus urticae decreased on shifting their diet to pollen. By contrast, females reared continuously on strawberry pollen produced as many eggs as females reared continuously on T. urticae. Survival and fecundity after UV-B irradiation were higher in females on the pollen diet. Oxygen radical absorbance capacity analysis revealed that the high antioxidant activity of strawberry pollen was due to four hydroxycinnamoyl spermidine derivatives.

CONCLUSION

Strawberry pollen was an adequate alternative food source for N. californicus. Feeding on strawberry pollen, which contains spermidine derivatives with high antioxidant activity, mitigated UV-B damage. This shows the potential of combining the UV-method with N. californicus for controlling T. urticae in strawberries.

Antioxidant Nanomaterial Based on Core⁻Shell Silica Nanospheres with Surface-Bound Caffeic Acid: A Promising Vehicle for Oxidation-Sensitive Drugs

The design of efficient, biocompatible, and easily prepared vehicles for drug delivery is a subject of great interest for medicine and pharmaceutical sciences. To achieve the above goals, surface functionalization is critical. Here, we report a hybrid nanocarrier consisting of core⁻shell silica nanospheres and the antioxidant caffeic acid linked to the surface, to evaluate their in vitro antioxidant capacity, their capability to protect oxidation-sensitive compounds incorporated in nanoparticles, and to study the interaction with bovine serum albumin protein. The results show that the radical-scavenging activity of immobilized caffeic acid is attenuated in the silica nanospheres; however, other antioxidant properties such as Fe2+-chelating activity and singlet oxygen quenching are enhanced. In addition, caffeic acid is protected from binding to proteins by the nanoparticle, suggesting that this nanosystem is more likely to maintain the antioxidant activity of caffeic acid in biological media. Finally, the natural antioxidant barrier on the nanocarrier is able to delay the degradation of a compound incorporated into this nanovehicle. Considering all findings, this work proposes a suitable tool for pharmaceutical and cosmetic industries as an antioxidant nanocarrier for oxidation-sensitive drugs.

Dietary chlorogenic acid supplementation affects gut morphology, antioxidant capacity and intestinal selected bacterial populations in weaned piglets

Chlorogenic acid (CGA), an ester formed between caffeic acid and quinic acid, is one of the most abundant phenolic acids and is widespread in fruits, vegetables, cereals and tuber crops. Therefore, the present study was conducted to test the hypothesis that dietary supplementation with CGA could improve intestinal health and regulate intestinal selected microbiota in weaned piglets. A total of twenty-four piglets (21 d of age) were randomly assigned to one of four groups according to their initial BW and sex and fed a basal diet (control group) or a basal diet containing 250, 500 and 1000 mg kg-1 CGA, respectively. The whole trial lasted for 28 d. Dietary CGA supplementation increased (P < 0.05) the duodenal villous height and villous height : crypt depth ratio, but decreased (P < 0.05) the F/G ratio and duodenal crypt depth when compared with the control group. Meanwhile, an increase (P < 0.05) in the jejunal villous height and in the ileal villous height : crypt depth ratio were also observed in CGA-fed piglets. Supplementation with CGA significantly increased (P < 0.05) the activity of serum GSH-Px and the activities of duodenal GSH-Px and CAT, upregulated (P < 0.05) the expression of OCLN in the duodenum and jejunum, and decreased (P < 0.05) the ileal MDA content when compared to the control group. In addition, an increase (P < 0.05) in the population of Lactobacillus and a decrease (P < 0.05) in the population of Escherichia coli were observed in the colon of pigs fed CGA diets. Furthermore, pigs fed CGA diets had higher (P < 0.05) propionic and butyric acid concentrations in the colon. Altogether, our results provide evidence that dietary CGA is beneficial for preserving intestinal morphological integrity and selectively regulating intestinal microbiota, which can provide a means to improve gut health and growth performance post-weaning.

The role of symmetric functionalisation on photoisomerisation of a UV commercial chemical filter

Photoisomerisation has been shown to be an efficient excited-state relaxation mechanism for a variety of nature-based and artificial-based molecular systems.

Mitochondria-Centric Review of Polyphenol Bioactivity in Cancer Models

SIGNIFICANCE

Humans are exposed daily to polyphenols in milligram-to-gram amounts through dietary consumption of fruits and vegetables. Polyphenols are also available as components of dietary supplements for improving general health. Although polyphenols are often advertised as antioxidants to explain health benefits, experimental evidence shows that their beneficial cancer preventing and controlling properties are more likely due to stimulation of pro-oxidant and proapoptotic pathways. Recent Advances: The understanding of the biological differences between cancer and normal cell, and especially the role that mitochondria play in carcinogenesis, has greatly advanced in recent years. These advances have resulted in a wealth of new information on polyphenol bioactivity in cell culture and animal models of cancer. Polyphenols appear to target oxidative phosphorylation and regulation of the mitochondrial membrane potential (MMP), glycolysis, pro-oxidant pathways, and antioxidant (adaptive) stress responses with greater selectivity in tumorigenic cells.

CRITICAL ISSUES

The ability of polyphenols to dissipate the MMP (Δψm) by a protonophore mechanism has been known for more than 50 years. However, researchers focus primarily on the downstream molecular effects of Δψm dissipation and mitochondrial uncoupling. We argue that the physicochemical properties of polyphenols are responsible for their anticancer properties by virtue of their protonophoric and pro-oxidant properties rather than their specific effects on downstream molecular targets.

FUTURE DIRECTIONS

Polyphenol-induced dissipation of Δψm is a physicochemical process that cancer cells cannot develop resistance against by gene mutation. Therefore, polyphenols should receive more attention as agents for cotherapy with cancer drugs to gain synergistic activity. Antioxid. Redox Signal.

Comparison between red wine and isolated trans-resveratrol on the prevention and regression of atherosclerosis in LDLr (-/-) mice

Moderate consumption of red wine has been widely associated with reduced cardiovascular risk, mainly due to its composition in phenolic compounds with antioxidant activity, such as resveratrol. The objective of this study was to compare the effect of red wine vs. trans-resveratrol consumption on the prevention and regression of atherosclerosis in LDLr ^(-/-) mice. This study consisted of two protocols: "Prevention" (PREV) and "Regression" (REGR). Both protocols included four groups: red wine (WINE), dealcoholized red wine (EXT), trans-resveratrol (RESV), and control (CONT). In PREV protocol, animals received a regular diet for 8 weeks and then switched to an atherogenic diet for the following 8 weeks, while the opposite was performed in REGR. Animals that received atherogenic diet after an initial period of standard diet (PREV) gained more body weight (39.25±2.30%) than the opposite (29.27±1.91%, P=.0013), suggesting an interaction between age and weight gain. Trans-resveratrol showed the highest hypocholesterolemic effect during PREV, reducing total cholesterol, LDL-C, VLDL-C and HDL-C. Supplementation with trans-resveratrol and dealcoholized red wine changed the fatty acids profile in the liver in both protocols, leading to an increase of MDA concentrations and SOD activity in the PREV protocol. In conclusion, supplementation with trans-resveratrol, red wine and the same wine without alcohol altered biomarkers of oxidative stress and lipidemia but had no effect on the prevention or regression of fatty streaks. These data suggest that cardiovascular protection associated with the "French Paradox" may be a result of synergistic effects between wine and the Mediterranean diet.

Chlorogenic Acid Prevents AMPA-Mediated Excitotoxicity in Optic Nerve Oligodendrocytes Through a PKC and Caspase-Dependent Pathways

In the CNS, including the optic nerve, oligodendrocytes play a critical role in the myelination of axons. Oligodendrocytes are exceptionally sensitive to insults to the CNS, such as injury, ischemia, or inflammation, which result in the loss of oligodendrocytes and myelin and eventually secondary axon degeneration. Oligodendrocytes are sensitive to excitotoxic insults mediated by overactivation of their AMPA ionotropic glutamate receptors. Phenolic compounds, which are widely distributed in fruits and vegetables, received the great attention of scientists due to their antioxidant activities and free radical scavenging abilities. Chlorogenic acid (CGA) has been demonstrated to possess potent neuroprotective activities against oxidative stress in various cellular models and pathological conditions. Hence, CGA protect against oxidative stress and excitotoxic insults mediated by AMPA receptors and that the protective mechanisms involve free radical scavenging, Ca²⁺ handling in the cytosol, and modulating antioxidant enzyme system. CGA was associated with the protein kinase A (PKC) signaling pathways transduction. Caspases and calpains have been studied as apoptotic mediators and cell death in this model of AMPA toxicity. Inhibitors of caspases initiators, caspases 1, 8, and 9, the upstream of caspase 3 effectors, have totally abrogated the protective activity of CGA. Inhibitors of calpains also totally abrogated the protective activity of CGA. In addition, a potential role for the CGA in inhibiting Bax in oligodendrocyte cell model undergoing AMPA is inducing excitotoxic death. Our results indicate that CGA exhibits a protective potential via antioxidant and apoptosis caspases and calpains dependent against AMPA-mediated excitotoxicity, and these finding indicate that CGA is able to be a good candidate for preventive approach for neurodegenerative disorders associated with loss and damage in oligodendrocytes and AMPA-mediated excitotoxicity.

Ultrafast dynamics of UV-excited trans- and cis-ferulic acid in aqueous solutions

The ultrafast UV-induced processes of the neutral, anionic and dianionic forms of trans- and cis-ferulic acid (FA) in aqueous solution were studied by static and femtosecond time-resolved emission and absorption spectroscopy combined with quantum chemical calculations. In all cases, initial excitation populates the first ¹ππ* state. For the dianionic cis-isomer cFA^2-, electronic deactivation takes place with a time constant of only 1.4 ps, whereas in all other cases, excited-state deactivation happens more than ten times slower, on a time scale of ≈20 ps. The data suggest sequential de-excitation pathways, where initial sub-picosecond solvent rearrangement and structural changes are followed by internal conversion to an intermediate excited electronic state from which deactivation to the ground state proceeds. Considering the time scales, barrierless excited-state pathways are suggested only in the case of cFA^2-, where the observed formation of the isomerisation photoproduct tFA^2- provides clear evidence for a cis ⇄ trans isomerisation coordinate. In the other cases, pathways with an excited-state energy barrier, presumably along the same coordinate, are likely, given the longer excited-state lifetimes.

Chemical findings and in vitro biological studies to uphold the use of Ficus exasperata Vahl leaf and stem bark

Ficus exasperata Vahl, commonly known as sandpaper, is a terrestrial Afro-tropical tree used in popular medicine. Despite the existence of some works on the biological activities of this species, its chemical composition is still poorly known. The aim of this study was to extend the knowledge on the phytochemistry and biological properties of this species. Aqueous extracts from F. exasperata leaves and stem bark were analysed. Thirty-one phenolic compounds, comprising cinnamoyl derivatives, flavonoid-O-glycosides, flavonoid-mono-C-glycosides, flavonoid-di-C-glycosides and one furanocoumarin, were determined by HPLC-DAD-ESI/MSⁿ and UPLC-ESI-QTOF-MS, 26 of them being reported for the first time in this species. The profile of organic acids, characterized by HPLC-UV, was also reported for the first time. The best radical scavenging activity was observed for the aqueous extract from leaves (IC₅₀ values of 222.5, 510.0 and 50.0 μg/mL against DPPH^•, ^•NO and O₂^•-, respectively). In addition, both aqueous extracts of the leaves and stem bark displayed a weak effect on α-amylase, and no cytotoxicity against gastric adenocarcinoma cell line, AGS. This study contributes to the valorisation of these vegetal materials, which may have application in functional foods and/or nutraceuticals.

Chlorogenic acid supplementation during in vitro maturation improves maturation, fertilization and developmental competence of porcine oocytes

Chlorogenic acid (CGA) is a quinic acid conjugate of caffeic acid, and a phytochemical found in many fruits and beverages that acts as an antioxidant. The present study investigated the effects of CGA supplementation during in vitro maturation (IVM), on in vitro development of porcine oocytes, to improve the porcine in vitro production (IVP) system. Oocytes were matured either without (control) or with CGA (10, 50, 100 and 200 μM). Subsequently, the matured oocytes were fertilized and cultured in vitro for 7 day. The rates of maturation, fertilization and blastocyst formation of oocytes matured with 50 μM CGA were significantly (p < .05) higher than those of the control oocytes. Hydrogen peroxide (H₂ O₂ ) is one of the reactive oxygen species and induces DNA damage in porcine oocytes. When oocytes were matured with 1 mM H₂ O₂ to assess the protective effect of CGA, 50 μM CGA supplementation improved the maturation rate and the proportion of DNA-fragmented nuclei in oocytes compared with control oocytes matured without CGA. Moreover, when oocytes were matured with either 50 μM CGA (control) or caffeic acid (10, 50 and 100 μM), the rates of maturation, fertilization and the blastocyst formation of oocytes matured with 50 μM CGA were similar to those of oocytes matured with 10 and 50 μM caffeic acid. Our results suggest that CGA has comparable effects to caffeic acid, and IVM with 50 μM CGA is particularly beneficial to IVP of porcine embryos and protects oocytes from DNA damage induced by oxidative stress. Supplementation of CGA to the maturation medium has a potential to improve porcine IVP system.

Hepatoprotective, Hypoglycemic, and Hypolipidemic Effect of Chokeberry Pomace on Polish Merino Lambs

To properly understand the biological effect of polyphenol compounds, it should not be assumed that they are generally bioavailable and are reaching tissues as expected. It is important to fully understand how polyphenol compounds are absorbed, metabolized, and finally eliminated from the organism. Most polyphenol compounds occur in the forms that cannot be absorbed in their primary form. Sheep make compounds bioavailable due to their unique digestive system properties. Despite this, several species of ruminants likely to serve as an experimental model were considered. However, due to the high costs for cattle and low popularity in the region of goats, sheep were selected as the experimental model. In the study, 24 Polish Merino lambs were randomly divided into a control and two experimental groups. The experimental groups were administered diets with the addition of 150 or 300 g of chokeberry pomace per each kg of complete feed mixture. Phenolics present in the chokeberry pomace were found to modulate biochemical blood parameters, resulting in hypoglycemic and hypolipidemic effects. Finally, the increase in total phenolics in the serum and liver of lambs induced a health-promoting effect on liver metabolic profile parameters.

Oxygen atoms are critical in rendering THP-1 leukaemia cells susceptible to cold physical plasma-induced apoptosis

Cold physical plasma has been suggested as a powerful new tool in oncology. However, some cancer cells such as THP-1 leukaemia cells have been shown to be resistant towards plasma-induced cell death, thereby serving as a good model for optimizing plasmas in order to foster pro-apoptotic anticancer effects. A helium/oxygen radio frequency driven atmospheric plasma profoundly induced apoptosis in THP-1 cells whereas helium, humidified helium, and humidified helium/oxygen plasmas were inefficient. Hydrogen peroxide – previously shown as central plasma-derived agent – did not participate in the killing reaction but our results suggest hypochlorous acid to be responsible for the effect observed. Proteomic analysis of THP-1 cells exposed to He/O₂ plasma emphasized a prominent growth retardation, cell stress, apoptosis, and a pro-immunogenic profile. Altogether, a plasma setting that inactivates previously unresponsive leukaemia cells is presented. Crucial reactive species in the plasma and liquid environment were identified and discussed, deciphering the complexity of plasma from the gas phase into the liquid down to the cellular response mechanism. These results may help tailoring plasmas for clinical applications such as oxidation-insensitive types of cancer.

Evaluation of Antioxidative Activity of Various Levels of Ethanol Extracted Tomato Powder and Application to Pork Patties

This study was performed to evaluate antioxidant activity of tomato powder extracted by various concentrations of ethanol (0, 25, 50, 75, 100%) and to evaluate the physicochemical properties and antioxidant activities of pork patties with ethanol extracted tomato (EET) powder. No differences in the contents of total of individual phenolic compounds including gallic acid and catechin, were observed among the treatments (p>0.05). Among the various concentrations, 50% and 75% EET powder showed the highest free radical scavenging and iron chelating activities (p<0.05). Lipid peroxidation was retarded in linoleic acid emulsion with the addition of 50% and 75% EET powder (0.1%). Based on the model study, five pork patties were actually manufactured; control patty, reference patty with 0.01% of butylated hydroxytoluene, patty with 1% of water extracted tomato (WET), and patties with 0.5 and 1.0% of EET. Addition of 1% WET and EET decreased pH value, and increased redness values of pork patties, as compared to the control (p<0.05). Pork patties with WET (1.0%) and EET (0.5% and 1.0%) had lower 2-thiobarbituric acid reactive substances values compared with control patties after 7 d of storage (p<0.05). Pork patties containing EET powder showed lower total bacterial and Enterobacteriaceae counts than control patties (p<0.05). In conclusion, WET and EET (50%) could be used as a natural antioxidant and antimicrobial agent in meat products.

Salicylic Acid Induction of Flavonoid Biosynthesis Pathways in Wheat Varies by Treatment

Salicylic acid is a promising compound for the reduction of stress sensitivity in plants. Although several biochemical and physiological changes have been described in plants treated with salicylic acid, the mode of action of the various treatments has not yet been clarified. The present work reports a detailed comparative study on the effects of different modes of salicylic acid application at the physiological, metabolomic, and transcriptomic levels. Seed soaking and hydroponic treatments were found to induce various changes in the protective mechanisms of wheat plants. The possible involvement of the flavonoid metabolism in salicylic acid-related stress signaling was also demonstrated. Different salicylic acid treatments were shown to induce different physiological and biochemical processes, with varying responses in the leaves and roots. Hydroponic treatment enhanced the level of oxidative stress, the expression of genes involved in the flavonoid metabolism and the amount of non-enzymatic antioxidant compounds, namely ortho-hydroxycinnamic acid and the flavonol quercetin in the leaves, while it decreased the ortho-hydroxycinnamic acid and flavonol contents and enhanced ascorbate peroxidase activity in the roots. In contrast, seed soaking only elevated the gene expression level of phenylalanine ammonia lyase in the roots and caused a slight increase in the amount of flavonols. These results draw attention to the fact that the effects of exogenous salicylic acid application cannot be generalized in different experimental systems and that the flavonoid metabolism may be an important part of the action mechanisms induced by salicylic acid.

The mvp2 mutation affects the generative transition through the modification of transcriptome pattern, salicylic acid and cytokinin metabolism in Triticum monococcum

Wild type and mvp2 (maintained vegetative phase) deletion mutant T. monococcum plants incapable of flowering were compared in order to determine the effect of the deleted region of chromosome 5A on transcript profile and hormone metabolism. This region contains the vernalization1 (VRN1) gene, a major regulator of the vegetative/generative transition. Transcript profiling in the crowns of T. monococcum during the transition and the subsequent formation of flower primordia showed that 306 genes were affected by the mutation, 198 by the developmental phase and 14 by the interaction of these parameters. In addition, 546 genes were affected by two or three factors. The genes controlled by the deleted region encode transcription factors, antioxidants and enzymes of hormone, carbohydrate and amino acid metabolism. The observed changes in the expression of the gene encoding phenylalanine ammonia lyase (PAL) might indicate the effect of mvp2 mutation on the metabolism of salicylic acid, which was corroborated by the differences in 2-hydroxycinnamic acid and cinnamic acid contents in both of the leaves and crowns, and in the concentrations of salicylic acid and benzoic acid in crowns during the vegetative/generative transition. The amount and ratio of active cytokinins and their derivatives (ribosides, glucosides and phosphates) were affected by developmental changes as well as by mvp2 mutation, too.

Photodynamics of potent antioxidants: ferulic and caffeic acids

The dynamics of ferulic acid (3-(4-hydroxy-3-methoxyphenyl)-2-propenoic acid) and caffeic acid (3-(3,4-dihydroxyphenyl)-2-propenoic acid) in acetonitrile, dioxane and water at pH 2.2 following photoexcitation to the first excited singlet state are reported. These hydroxycinnamic acids display both strong ultraviolet absorption and potent antioxidant activity, making them promising sunscreen components. Ferulic and caffeic acids have previously been shown to undergo trans-cis photoisomerization via irradiation studies, yet time-resolved measurements were unable to observe formation of the cis-isomer. In the present study, we are able to observe the formation of the cis-isomer as well as provide timescales of relaxation following initial photoexcitation.

Ultrafast Photoprotecting Sunscreens in Natural Plants

We explore the ultrafast photoprotective properties of a series of sinapic acid derivatives in a range of solvents, utilizing femtosecond transient electronic absorption spectroscopy. We find that a primary relaxation mechanism displayed by the plant sunscreen sinapoyl malate and other related molecular species may be understood as a multistep process involving internal conversion of the initially photoexcited 1(1)ππ* state along a trans-cis photoisomerization coordinate, leading to the repopulation of the original trans ground-state isomer or the formation of a stable cis isomer.

Caffeic acid, a phyto polyphenol mitigates fluoride induced hepatotoxicity in rats: A possible mechanism

Fluoride induced hepatotoxicity has been extensively studied in both humans and animals. However, the mechanism underlying in the hepatotoxicity of experimental fluorosis remains obscure. The severity of fluoride toxicity was reduced by oral administration of certain plant derived antioxidants. Caffeic acid (CA) a polyphenolic compound has diverse range of pharmacological activity in the biological system. Therefore, the present study was aimed to investigate the protective mechanism of CA, against fluoride induced hepatotoxicity in rats. The rats were treated with 300 ppm of NaF via drinking water ad libitum alone and in combination with CA at a dose of 50 mg/kg daily for 30 days by oral intubation. CA treatment significantly prevented fluoride induced hepatic damage as evident from the histopathological studies and declined levels of serum fluoride and liver marker enzymes. A significant decrease in the levels of enzymatic (SOD2, CAT, GPx, and GSTpi class) and nonenzymatic (GSH and Vitamin C) antioxidants along with increased ROS, lipid peroxidation, protein carbonyl content, and nitrate levels by fluoride were also prevented in these groups. In addition, CA inhibits fluoride induced apoptosis by altering the Bax and caspase-3p20 expressions. Further, fluoride induced upregulation of Nox4, p38α MAPK, Hsp60, and downregulation of Hsp27 are the indicators for the detection of oxidative damage, apoptosis, and mitochondrial stress was also modulated by CA. These findings reveal that CA supplementation has a protective effect against fluoride induced hepatotoxicity in rats.

Role of caffeic Acid on collagen production in nasal polyp-derived fibroblasts

Objectives

Caffeic acids are known to have anti-oxidant, anti-inflammatory, immunomodulatory, and tissue reparative effects. The purposes of this study were to determine the effect of caffeic acid on transforming growth factor (TGF) β1-induced myofibroblast differentiation and collagen production, and to determine whether caffeic acid is involved in the antioxidant effect in nasal polyp-derived fibroblasts (NPDFs).

Methods

NPDFs were pretreated with caffeic acid (1-10 µM) for 2 hours and stimulated with TGF-β1 (5 ng/mL) for 24 hours. The expression of α-smooth muscle actin (SMA), collagen types I and III, and Nox4 mRNA was determined by a reverse transcription-polymerase chain reaction, and the expression of α-SMA protein was determined by actin ned by immunofluorescence microscopy. The amount of total soluble collagen production was analyzed by the Sircol collagen dye-binding assay. The reactive oxygen species (ROS) generated by NPDFs were determined using 2',7'-dichlorfluorescein-diacetate. siNox4 was used to determine the effect of Nox4.

Results

The expression of α-SMA and production of collagen were significantly increased following TGF-β1 treatment. In contrast, the level of expression of α-SMA and the level of production of collagen were decreased by pretreatment with caffeic acid. The activation of Nox4 and the subsequent production of ROS were also reduced by pretreatment with caffeic acid. The expression of α-SMA was prevented by inhibition of ROS generation with siNox4.

Conclusion

Caffeic acid may inhibit TGF-β1-induced differentiation of fibroblasts into myofibroblasts and collagen production by regulating ROS.

Synthesis and role of salicylic acid in wheat varieties with different levels of cadmium tolerance

Wheat genotypes with different endogenous SA contents were investigated, in order to reveal how cadmium influences salicylic acid (SA) synthesis, and to find possible relationships between SA and certain protective compounds (members of the antioxidants and the heavy metal detoxification system) and between the SA content and the level of cadmium tolerance. Cadmium exposure induced SA synthesis, especially in the leaves, and it is suggested that the phenyl-propanoid synthesis pathway is responsible for the accumulation of SA observed after cadmium stress. Cadmium influenced the synthesis and activation of protective compounds to varying extents in wheat genotypes with different levels of tolerance; the roots and leaves also responded differently to cadmium stress. Although a direct relationship was not found between the initial SA levels and the degree of cadmium tolerance, the results suggest that the increase in the root SA level during cadmium stress in the Mv varieties could be related with the enhancement of the internal glutathione cycle, thus inducing the antioxidant and metal detoxification systems, which promote Cd stress tolerance in wheat seedlings. The positive correlation between certain SA-related compounds and protective compounds suggests that SA-related signalling may also play a role in the acclimation to heavy metal stress.

Scavenging rate constants of hydrophilic antioxidants against multiple reactive oxygen species

Scavenging rate constants of eight hydrophilic antioxidants, including caffeic acid, chlorogenic acid, genistein, glutathione, N-acetylcysteine, rutin, trolox, and uric acid against multiple ROS, namely superoxide anion, hydroxyl radical, singlet oxygen, and alkoxyl radical were determined with the electron spin resonance method. Direct flash photolysis measurement of the second-order rate constant in the reaction of alkoxyl radical plus the spin trap 5,5-dimethyl-pyrroline N-oxide made it possible to evaluate scavenging rate constants in antioxidants. The magnitudes of scavenging rate constants were notably dependent on the character of each ROS and the overall rate constants were highest in hydroxyl radical scavenging and the lowest in superoxide anion. The highest scavenging rate constant against superoxide anion was obtained by chlorogenic acid (2.9 × 10(5) M(-1) s(-1)) and the lowest was by N-acetylcysteine (5.0 × 10(2) M(-1) s(-1)). For singlet oxygen, the highest was by glutathione (9.4 × 10(8) M(-1) s(-1)) and the lowest was by uric acid (2.3 × 10(6) M(-1) s(-1)). All other numbers are listed and illustrated. Redox potential measurements of the antioxidants indicated that the antioxidants are likely to react with superoxide anion and singlet oxygen through electron transfer processes.

Scavenging rate constants of hydrophilic antioxidants against multiple reactive oxygen species

Scavenging rate constants of eight hydrophilic antioxidants, including caffeic acid, chlorogenic acid, genistein, glutathione, N-acetylcysteine, rutin, trolox, and uric acid against multiple ROS, namely superoxide anion, hydroxyl radical, singlet oxygen, and alkoxyl radical were determined with the electron spin resonance method. Direct flash photolysis measurement of the second-order rate constant in the reaction of alkoxyl radical plus the spin trap 5,5-dimethyl-pyrroline N-oxide made it possible to evaluate scavenging rate constants in antioxidants. The magnitudes of scavenging rate constants were notably dependent on the character of each ROS and the overall rate constants were highest in hydroxyl radical scavenging and the lowest in superoxide anion. The highest scavenging rate constant against superoxide anion was obtained by chlorogenic acid (2.9 × 10⁵ M⁻¹ s⁻¹) and the lowest was by N-acetylcysteine (5.0 × 10² M⁻¹ s⁻¹). For singlet oxygen, the highest was by glutathione (9.4 × 10⁸ M⁻¹ s⁻¹) and the lowest was by uric acid (2.3 × 10⁶ M⁻¹ s⁻¹). All other numbers are listed and illustrated. Redox potential measurements of the antioxidants indicated that the antioxidants are likely to react with superoxide anion and singlet oxygen through electron transfer processes.

Effect of dietary antioxidants on the cytostatic effect of acrylamide during copper-deficiency in Saccharomyces cerevisiae

Yeast grown on a copper deficient medium was used to study acrylamide toxicity, obviating the need for genetic manipulation and accompanying compensatory effects.

An antioxidant bioinspired phenolic polymer for efficient stabilization of polyethylene

The synthesis, structural characterization and properties of a new bioinspired phenolic polymer (polyCAME) produced by oxidative polymerization of caffeic acid methyl ester (CAME) with horseradish peroxidase (HRP)-H2O2 is reported as a new sustainable stabilizer toward polyethylene (PE) thermal and photo-oxidative degradation. PolyCAME exhibits high stability toward decarboxylation and oxidative degradation during the thermal processes associated with PE film preparation. Characterization of PE films by thermal methods, photo-oxidative treatments combined with chemiluminescence, and FTIR spectroscopy and mechanical tests indicate a significant effect of polyCAME on PE durability. Data from antioxidant capacity tests suggest that the protective effects of polyCAME are due to the potent scavenging activity on aggressive OH radicals, the efficient H-atom donor properties inducing free radical quenching, and the ferric ion reducing ability. PolyCAME is thus proposed as a novel easily accessible, eco-friendly, and biocompatible biomaterial for a sustainable approach to the stabilization of PE films in packaging and other applications.

Catabolism of coffee chlorogenic acids by human colonic microbiota

Several studies have indicated potential health benefits associated with coffee consumption. These benefits might be ascribed in part to the chlorogenic acids (CGAs), the main (poly)phenols in coffee. The impact of these dietary (poly)phenols on health depends on their bioavailability. As they pass along the gastrointestinal tract, CGAs are metabolized extensively and it is their metabolites rather than the parent compounds that predominate in the circulatory system. This article reports on a study in which after incubation of espresso coffee with human fecal samples, high-performance liquid chromatography-mass spectrometry (HPLC-MS) and gas chromatography-mass spectrometry (GC-MS) were used to monitor CGA breakdown and identify and quantify the catabolites produced by the colonic microflora. The CGAs were rapidly degraded by the colonic microflora and over the 6-h incubation period, 11 catabolites were identified and quantified. The appearance of the initial degradation products, caffeic and ferulic acids, was transient, with maximum quantities at 1 h. Dihydrocaffeic acid, dihydroferulic acid, and 3-(3'-hydroxyphenyl)propionic acid were the major end products, comprising 75-83% of the total catabolites, whereas the remaining 17-25% consisted of six minor catabolites. The rate and extent of the degradation showed a clear influence of the composition of the gut microbiota of individual volunteers. Pathways involved in colonic catabolism of CGAs are proposed and comparison with studies on the bioavailability of coffee CGAs ingested by humans helped distinguish between colonic catabolites and phase II metabolites of CGAs.

Caffeic acid protects tissue antioxidants and DNA content in methamphetamine induced tissue toxicity in Sprague Dawley rats

Caffeic acid (CA) (3,4-dihydroxycinnamic acid) is among the major hydroxycinnamic acids. Hydroxycinnamic acid is the major subgroup of phenolic compounds. Methamphetamine (METH) is a potent addictive psychostimulant. Chronic use and acute METH intoxication can cause substantial medical consequences, including spleen, kidney, liver and heart. The objective of the present study was to evaluate the antioxidant activity of CA to protect against oxidative stress and DNA damage to various organs in METH toxicity. Thirty-two male Sprague Dawley (SD) rats were divided into four equal groups: group 1 was injected (i.p) with saline (1 mL/kg) while groups 2,3 and 4 were injected (i.p) with METH (10 mg/kg) twice a day over five days period. Where 100 & 200 mg/kg of CA were injected (i.p) into groups 3 and 4, respectively one day before exposure to METH injections. Tissue antioxidants and DNA content were evaluated in different tissues. METH decreased glutathione (GSH) and glutathione peroxidase (GPx) levels while increased malondialdehyde (MDA), catalase (CAT) and protein carbonyl levels in brain (hypothalamus), liver, and kidney tissues of rats. METH increased hyperdiploidy in these tissues and DNA damage results. Prior treatment of CA to animals exposed to METH restores the above parameters to the normal levels and preserves the DNA content of these tissues. These results were supported by histopathological investigations. In conclusion, METH induced oxidative stress and DNA damage and pretreatment of CA before METH injections prevented tissue oxidative stress and DNA damage in METH-treated animals.

Effects of molecular structure on kinetics and dynamics of the trolox equivalent antioxidant capacity assay with ABTS(+•)

Reaction kinetics in the Trolox equivalent antioxidant capacity (TEAC) assay between ABTS(+•) [2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical] and compounds with different structure, molecular weight, number of OH groups, and redox potential were investigated by recording loss of ABTS(+•) absorbance (734 nm) continuously over time. Curves showed six distinguishable kinetic patterns, including both immediate and extended reaction components. Radical quenching rates in the immediate component most relevant to reactions in foods and tissues depended on phenol structure and steric accessibility to the hindered radical, while reaction stoichiometry correlated with the number of phenol groups (>0.81) but not redox potential. Current assay procedures measure antioxidant capacity under conditions not relevant to actual applications and do not determine radical quenching rates. Results raise serious questions regarding the ability of reactions with the hindered ABTS(+•) to rank actual radical quenching by compounds with different structures and invalidate reporting antioxidant activity as Trolox equivalents.

Histolocalization and physico-chemical characterization of dihydrochalcones: Insight into the role of apple major flavonoids

Flavonoids, like other metabolites synthesized via the phenylpropanoid pathway, possess a wide range of biological activities including functions in plant development and its interaction with the environment. Dihydrochalcones (mainly phloridzin, sieboldin, trilobatin, phloretin) represent the major flavonoid subgroup in apple green tissues. Although this class of phenolic compounds is found in very large amounts in some tissues (≈200mg/g of leaf DW), their physiological significance remains unclear. In the present study, we highlight their tissue-specific localization in young growing shoots suggesting a specific role in important physiological processes, most notably in response to biotic stress. Indeed, dihydrochalcones could constitute a basal defense, in particular phloretin which exhibits a strong broad-range bactericidal and fungicidal activity. Our results also indicate that sieboldin forms complexes with iron with strong affinity, reinforcing its antioxidant properties and conferring to this dihydrochalcone a potential for iron seclusion and/or storage. The importance of localization and biochemical properties of dihydrochalcones are discussed in view of the apple tree defense strategy against both biotic and abiotic stresses.

Efficacy of trans-2-hydroxycinnamic Acid against trichlorfon-induced oxidative stress in wistar rats

Trichlorfon is an organophosphate insecticide used to control cockroaches, crickets, silverfish, bedbugs, fleas, cattle grubs, flies, ticks, leaf miners, and leaf-hoppers. It is also used to treat domestic animals for control of internal parasites. Trans-2-hydroxycinnamic acid (T2HCA) is a hydroxyl derivative of cinnamic acid. The present study highlights trichlorofon-induced toxicity and the protective role of T2HCA in the liver, kidney, and brain of female Wistar rats. The rats were given a single dose of trichlorofon (150 mg / kg bw) and pre- and post-treatment T2HCA (50 mg / kg bw) for seven days. Trichlorofon enhanced oxidative stress in liver, kidney, and brain of the rats, which was evident from the elevation of lipid peroxidation (LPO). The reduced level of non-enzymatic antioxidant glutathione (GSH) also indicated the presence of an oxidative insult. The activity of enzymatic antioxidants like superoxide dismutase (SOD), catalase (CAT), glutathione-s-transferase (GST), glutathione reductase (GR), and glutathione peroxidase (GPx) was significantly decreased on trichlorfon administration. Pre and post treatment with T2HCA decreased the LPO level and increased SOD, CAT, GST, GR, GPx, and GSH in the brain, liver, and kidney. Trichlorfon-induced reduction in acelylcholinestrase was also ameliorated with T2HCA treatment. In conclusion, trichlorfon-mediated induction in the reactive oxygen species and disturbance in the antioxidant enzymes’ defense system was moderately ameliorated by antioxidant trans-2-hydroxycinnamic acid.

Biosynthesis, natural sources, dietary intake, pharmacokinetic properties, and biological activities of hydroxycinnamic acids

Hydroxycinnamic acids are the most widely distributed phenolic acids in plants. Broadly speaking, they can be defined as compounds derived from cinnamic acid. They are present at high concentrations in many food products, including fruits, vegetables, tea, cocoa, and wine. A diet rich in hydroxycinnamic acids is thought to be associated with beneficial health effects such as a reduced risk of cardiovascular disease. The impact of hydroxycinnamic acids on health depends on their intake and pharmacokinetic properties. This review discusses their chemistry, biosynthesis, natural sources, dietary intake, and pharmacokinetic properties.

Interactions between α-tocopherol and rosmarinic acid and its alkyl esters in emulsions: synergistic, additive, or antagonistic effect?

Many antioxidants can interact to produce synergistic interactions that can more effectively inhibit lipid oxidation in foods. Esterification of rosmarinic acid produces a variety of compounds with different antioxidant activity due to differences in polarity and thus differences in partitioning in oil, water, and interfacial regions of oil-in-water emulsions (O/W). Therefore, rosmarinic acid and rosmarinate esters provide an interesting tool to study the ability of antioxidant to interact in O/W emulsions. In O/W emulsions, rosmarinic acid (R0) exhibited the strongest synergistic interaction with α-tocopherol while butyl (R4) and dodecyl (R12) rosmarinate esters exhibited small synergistic interaction and eicosyl rosmarinate esters (R20) exhibited slightly antagonistic interaction. Fluorescence quenching and electron paramagnetic resonance (EPR) studies showed that water-soluble rosmarinic acid (R0) exhibited more interactions with α-tocopherol than any of the tested esters (R4, R12, R20). This was also confirmed in O/W emulsions where R0 altered the formation of α-tocopherol quinone and α-tocopherol increased the formation of caffeic acid from R0. This formation of caffeic acid was proposed to be responsible for the synergistic activity of R0 and α-tocopherol since the formation of an additional antioxidant could further increase the oxidative stability of the emulsion.

Hydrolysis of chicoric and caftaric acids with esterases and Lactobacillus johnsonii in Vitro and in a gastrointestinal model

Chicoric acid (ChA) and caftaric acid (CafA) were identified as bioactive components of chicory and have been ascribed a number of health benefits. This study investigated the hydrolysis of ChA and CafA with enzymes and a probiotic bacterium Lactobacillus johnsonii (La1). Esterase from Aspergillus japonicus (24 U/mg) hydrolyzed 100% of ChA (5 mM) and CafA (5 mM) after 3 h, at pH 7.0 and 37 °C. Under the same reaction conditions, 100% hydrolysis of ChA and CafA was achieved with a spray-dried preparation of La1. The addition of La1 (100 mg/mL, 3.3 E9 cfu/g) to CafA solution in a gastrointestinal model (GI model) resulted in 65% hydrolysis of CafA. This model simulates the physicochemical conditions of the human gastrointestinal tract. No hydrolysis of CafA was observed after passage through the GI model in the absence of La1. The results of this study support the hypothesis that ChA and CafA are degraded by gut microflora before absorption and metabolization.