Antioxidant activity of hydroxycinnamic acids on human low-density lipoprotein oxidation

Prolonged on-tree maturation vs. cold storage of Hass avocado fruit: Changes in metabolites of bioactive interest at edible ripeness

When the recipient of the product is relatively distant from the production area, it is necessary to use cold storage and controlled humidity to transport the avocado fruits. One of the main advantages of local avocado consumption lies on the possibility of prolonging on-tree maturation; this could foreseeably modify the metabolic profile of the fruit that reaches the consumer. In this work, the effect of prolonged on tree maturation (during different time intervals) on the final composition of avocado fruit (at edible ripeness) was evaluated and compared with the impact of the same periods after prolonged cold storage. The quantitative evolution of nine bioactive metabolites (7 phenolic compounds, pantothenic and abscisic acids) over 40 days (10-days intervals) was studied by using a solid-liquid extraction protocol and a LC-MS methodology. The results were discussed both considering the quantitative evolution of each individual compound and the sum of all of them.

Hypolipidemic activity of P-methoxycinnamic diester (PCO-C) isolated from Copernicia prunífera against Triton WR-1339 and hyperlipidemic diet in mice

Carnauba wax is extracted from the leaves of the Copernicia prunífera and contains approximately 80% of esters in its composition. The purpose of the present study was evaluate the hypolipidemic effect of p-methoxycinnamic diesters (PCO-C) extracted from Copernicia prunífera in a model of acute and chronic dyslipidemia in mice. The levels of total cholesterol and triglycerides were significantly reduced plasma levels in PCO-C at the dose of 100mg/kg in a model of acute and chronic dyslipidemia. Histological studies showed that PCO-C has no hepatotoxic effect and reduces hepatic steatosis in animals that consumed hyperlipidemic ration. Thus, it was concluded that PCO-C isolated from Copernicia Prunifera was effective in reducing total cholesterol and triglyceride levels in both dyslipidemia induction models. The finding indicates that PCO-C might be beneficial in treatment of hyperlipidemia and atherosclerosis.

Phenolic Profile and Antioxidant Activity of Melon (Cucumis Melo L.) Seeds from Pakistan

Phenolic composition of different extracts of honeydew melon seeds and their antioxidant activity was determined for the first time. Phenolic compounds were identified using a reversed phase high performance liquid chromatography with diode array detection (HPLC-DAD) method. Results showed the identification of five phenolic compounds in water extract namely gallic acid and its derivative, hydroxybenzoic acid and catechin derivatives and caffeic acid. There were nine phenolic compounds identified in methanol–water extract, which are caffeic acid, two vanillic acid derivatives, ellagitanins, quercetin-3-rutinoside, derivatives of syringic acid and ellagic acid. The amounts of gallic acid, caffeic acid and catechin were higher among all phenolic compounds. Total phenolic compounds and radical scavenging activity were higher in water and methanol–water extract than their corresponding methanol extracts. In conclusion, melon seeds are a good source of natural antioxidants with significant biological functions and may serve as food ingredients and as fortifying material for maintaining shelf life.

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.

Hydroxycinnamic acids in Crepidiastrum denticulatum protect oxidative stress-induced retinal damage

We investigated the effects of an ethanol extract of C. denticulatum (EECD) in a mouse model of glaucoma established by optic nerve crush (ONC), and found that EECD significantly protected against retinal ganglion cell (RGC) death caused by ONC. Furthermore, EECD effectively protected against N-methyl-d-aspartate-induced damage to the rat retinas. In vitro, EECD attenuated transformed retinal ganglion cell (RGC-5) death and significantly blunted the up-regulation of apoptotic proteins and mRNA level induced by 1-buthionine-(S,R)-sulfoximine combined with glutamate, reduced reactive oxygen species production by radical species, and inhibited lipid peroxidation. The major EECD components were found to be chicoric acid and 3,5-dicaffeoylquinic acid (3,5-DCQA) that have shown beneficial effects on retinal degeneration both in vitro and in vivo studies. Thus, EECD could be used as a natural neuroprotective agent for glaucoma, and chicoric acid and 3,5-DCQA as mark compounds for the development of functional food.

Nutritional countermeasures targeting reactive oxygen species in cancer: from mechanisms to biomarkers and clinical evidence

Reactive oxygen species (ROS) exert various biological effects and contribute to signaling events during physiological and pathological processes. Enhanced levels of ROS are highly associated with different tumors, a Western lifestyle, and a nutritional regime. The supplementation of food with traditional antioxidants was shown to be protective against cancer in a number of studies both in vitro and in vivo. However, recent large-scale human trials in well-nourished populations did not confirm the beneficial role of antioxidants in cancer, whereas there is a well-established connection between longevity of several human populations and increased amount of antioxidants in their diets. Although our knowledge about ROS generators, ROS scavengers, and ROS signaling has improved, the knowledge about the direct link between nutrition, ROS levels, and cancer is limited. These limitations are partly due to lack of standardized reliable ROS measurement methods, easily usable biomarkers, knowledge of ROS action in cellular compartments, and individual genetic predispositions. The current review summarizes ROS formation due to nutrition with respect to macronutrients and antioxidant micronutrients in the context of cancer and discusses signaling mechanisms, used biomarkers, and its limitations along with large-scale human trials.

Amelioration by chicory seed extract of diabetes- and oleic acid-induced non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) via modulation of PPARα and SREBP-1

We evaluated the effect of chicory (Cichorium intybus L.) seed extract (CI) on hepatic steatosis caused by early and late stage diabetes in rats (in vivo), and induced in HepG2 cells (in vitro) by BSA-oleic acid complex (OA). Different dosages of CI (1.25, 2.5 and 5 mg/ml) were applied along with OA (1 mM) to HepG2 cells, simultaneously and non-simultaneously; and without OA to ordinary non-steatotic cells. Cellular lipid accumulation and glycerol release, and hepatic triglyceride (TG) content were measured. The expression levels of sterol regulatory element-binding protein-1c (SREBP-1c) and peroxisome proliferator-activated receptor alpha (PPARα) were determined. Liver samples were stained with hematoxylin and eosin (H&E). Significant histological damage (steatosis-inflammation-fibrosis) to the cells and tissues and down-regulation of SREBP-1c and PPARα genes that followed steatosis induction were prevented by CI in simultaneous treatment. In non-simultaneous treatment, CI up-regulated the expression of both genes and restored the normal levels of the corresponding proteins; with a greater stimulating effect on PPARα, CI acted as a PPARα agonist. CI released glycerol from HepG2 cells, and targeted the first and the second hit phases of hepatic steatosis. A preliminary attempt to characterize CI showed caffeic acid, chlorogenic acid, and chicoric acid, among the constituents.

Chemical constituents with free-radical-scavenging activities from the stem of Fissistigma polyanthum

BACKGROUND

Fissistigma polyanthum is a liane belonging to the Annonaceae family and it is one of the most important crude drugs in traditional Chinese medicine.

OBJECTIVE

The objective was to describe the structural elucidation and the free-radical-scavenging activities of the isolated compounds from Fissistigma polyanthum.

MATERIAL AND METHODS

The chemical constituents were isolated and purified by normal, reverse column chromatography and HPLC. Their structures were identified by spectroscopic methods ((1)H NMR and (13)C NMR) and by comparison with literature values, and the free-radical-scavenging activities of these two compounds were also evaluated through three in vitro model systems (DPPH, trolox equivalent antioxidant capacity (TEAC) and Co (II) EDTA-induced luminol chemiluminescence by flow injection).

RESULTS

Two known compounds, named kanakugiol (1) and teutenone A (2), were isolated from the stem of Fissistigma polyanthum for the first time, and compound 1 exhibited moderate free-radical-scavenging activity.

CONCLUSION

Fissistigma polyanthum, which has traditionally been used as an important Chinese medicine, showed a certain free-radical-scavenging activity.

Structural identification of isomallotusinin and other phenolics in Phyllanthus emblica L. fruit hull

The air-dried fruit hull of Phyllanthus emblica L. was extracted with 95% ethanol, and then the extract was partitioned by diethyl ether and ethyl acetate (EA). The EA fraction was then subjected to separation and purification using silica gel and Sephadex LH-20 column chromatography repeatedly to obtain five hydrolysable tannins. They were identified as mucic acid 1,4-lactone 3-o-gallate (C1), isocorilagin (C2), chebulanin (C3), chebulagic acid (C4) and isomallotusinin (C5) using mass spectrometry and nuclear magnetic resonance (NMR) spectrometry. Isomallotusinin and chebulanin were identified from emblica dried fruit hull for the first time, and isomallotusinin was the first time identified from Phyllanthus. Furthermore, the antioxidant abilities of these hydrolysable tannins were investigated using DPPH and ABTS⁺ radical scavenging systems. All hydrolysable tannins showed strong DPPH and ABTS⁺ radical scavenging activities. Isomallotusinin and chebulagic acid exhibited the highest antioxidant activity compared to other purified compounds tested.

Mediterranean Diet Effect: an Italian picture

BACKGROUND

The purpose of this study was to evaluate the overall diet quality effects, mainly on antioxidant nutritional status and some cytokines related to the cellular immune response as well as oxidative stress in a healthy Italian population group.

METHODS

An observational study was conducted on 131 healthy free-living subjects. Dietary intake was assessed by dietary diary. Standardised procedures were used to make anthropometric measurements. On blood samples (serum, plasma and whole blood) were evaluated: antioxidant status by vitamin A, vitamin E, carotenoids, vitamin C, uric acid, SH groups, SOD and GPx activities; lipid blood profile by total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides; total antioxidant capacity by FRAP and TRAP; the immune status by TNF-α, and IL-10 cytokines; the levels of malondialdehyde in the erythrocytes as marker of lipid peroxidation.

RESULTS

The daily macronutrients intake (g/day) have shown a high lipids consumption and significant differences between the sexes with regard to daily micronutrients intake. On total sample mean Mediterranean Diet Score (MDS) was 4.5 ± 1.6 and no significant differences between the sexes were present. A greater adherence to a Mediterranean dietary pattern increases the circulating plasma levels of carotenoids (lutein plus zeaxanthin, cryptoxanthin, α and β-carotene), vitamin A and vitamin E. The levels of endogenous antioxidants were also improved. We observed higher levels in anti-inflammatory effect cytokines (IL-10) in subjects with MDS ≥ 6, by contrast, subjects with MDS ≤ 3 show higher levels in sense of proinflammatory (TNF α P < 0.05). Lower levels of MDA were associated with MDS > 4. Our data suggest a protective role of vitamin A against chronic inflammatory conditions especially in subjects with the highest adherence to the Mediterranean-type dietary pattern.

CONCLUSIONS

Mediterranean dietary pattern is associated with significant amelioration of multiple risk factors, including a better cardiovascular risk profile, reduced oxidative stress and modulation of inflammation.

Chemical constituents with free-radical-scavenging activities from the stem of Microcos paniculata

The free-radical-scavenging activities of various solvent extracts of Microcos paniculata were evaluated through in vitro model systems, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonate) (ABTS) and Co (II) EDTA-induced luminol chemiluminescence by flow injection. In all three of these systems the ethyl acetate (EtOAc) extract showed the highest free-radical-scavenging activity compared with the other three (n-BuOH, water and petroleum ether) extracts. Free-radical-scavenging assay-guided chromatographic separation of the EtOAc extract, using a normal-phase and reverse-phase silica gel column chromatography yielded five compounds: a new triterpene named methyl 3beta-O-p-hydroxy-E-cinnamoyloxy-2alpha,23-dihydroxyolean-12-en-28-oate (1), whose spectral data are presented for the first time, together with four known compounds, epicatechin (2), 3-trans-feruloyl maslinic acid (3), maslinic acid (4) and sucrose (5). All of the compounds were isolated from Microcos paniculata for the first time. The compounds were identified by spectroscopic methods. Among them, compound 2 displayed significant free-radical-scavenging activity which is similar to that of standard antioxidant ascorbic acid (V(C)) and therefore may be a promising natural antioxidant.

Plant phenolics regulate neoplastic cell growth and survival: a quantitative structure-activity and biochemical analysis

The anti-tumour activities of many plant phenolics at high concentrations (>100 micromol/L) suggest their potential use as dietary supplements in cancer chemoprevention and cancer chemotherapy. However, it is not clear what impact phenolic compounds have at the physiological concentrations obtained through consumption of high phenolic diets on neoplastic cells. In the present study, 54 naturally occurring phenolics were evaluated at physiologically relevant concentrations for their capacity to alter PC12 cell viability in response to serum deprivation, the chemotherepeutic agent etoposide, and the apoptogen C2-ceramide. Surprisingly, novel mitogenic, cytoprotective, and antiapoptotic activities were detected. Quantitative structure-activity relationship modelling indicated that many of these activities could be predicted by compound lipophilicity, steric bulk, and (or) antioxidant capacity, with the exception of inhibition of ceramide-induced apoptosis. Where quantitative structure-activity relationship analysis was insufficient, biochemical assessment demonstrated that the benzoate orsellinic acid blocked downstream caspase-12 activation following ceramide challenge. These findings demonstrate substantive mitogenic, cytoprotective, and antiapoptotic biological activities of plant phenolics on neoplastic cells at physiologically relevant dietary concentrations that should be considered in chemopreventive and chemotherapeutic strategies.