The antioxidant properties of theaflavins and their gallate esters--radical scavengers or metal chelators?

Sulforaphane ameliorate Arsenic induced cardiotoxicity in rats: Role of PI3k/Akt mediated Nrf2 signaling pathway

Arsenic (As) toxicity can generate reactive free radicals, which play an important role in the evolution of cardiomyopathy. The aim of this research is to see if sulforaphane (SFN) protects against As-induced heart damage, oxidative stress, and mitochondrial complex dysfunction via the PI3K/Akt/Nrf2 signaling pathway. The rats were placed into four groups, each with eight rats. Group 1: Normal rats (control group); Group 2: Treatment group (5 mg/kg body weight); Group 3: SFN+As-treatment group (80 mg/kg body weight + 5 mg/kg body weight); Group 4: SFN group only (80 mg/kg body weight). The swot will last 4 weeks. At the end of the intermission (28 days), all of the rats starved overnight and killed with cervical decapitation. As administration considerably (p < 0.05) inflated the extent of free radicals (O2-, OH-), lipoid peroxidation (malondialdehyde, 4-hydroxynonenal), lipoid profile (low-density lipoprotein-cholesterol, very low-density lipoprotein-cholesterol (VLDL-C), total cholesterol, triglyceride, and phospholipids), cardiac Troponin (cTnT&I), and Mitochondrial complex III. A noteworthy (p < 0.05) diminish the level of HDL-C, Mitochondrial complex I and II, enzymatic (superoxide dismutase, catalase, and glutathione peroxidase), and nonenzymatic antioxidant (glutathione and total sulfhydryl groups) and PI3k, Akt, and Nrf2 sequence in As treated rats. The western blot, real-time polymerase chain reaction, flowcytometric, and histology studies all corroborated the biochemical findings which revealed significant heart damage in rats. Pretreatment with SFN significantly (p < 0.05) reduced the invitro free radicals, lipid oxidative indicators, mitochondrial complex, lipid profiles, and increased phase II antioxidants in the heart. This result shows that dietary supplementation of SFN protects against As-induced cardiotoxicity via PI3k/Akt/Nrf2 pathway in rats.

β-caryophyllene blocks reactive oxygen species-mediated hyperlipidemia in isoproterenol-induced myocardial infarcted rats

Myocardial infarction (MI) is a leading cause of death. Lipid-lowering interventions have been shown to decrease coronary events and mortality of MI and heart failure. In this investigation, we assessed the anti-hyperlipidemic effects of β-caryophyllene in isoproterenol-induced myocardial infarcted rats. β-Caryophyllene (20 mg/kg body weight) pre-and co-treatment was given to rats orally, daily, for 3 weeks. Isoproterenol (100 mg/kg body weight) was administered to rats to induce MI. The levels of serum cardiac troponins T and I, serum and heart total cholesterol, triglycerides, free fatty acids, and the levels of serum low-density and very low-density lipoprotein-cholesterols were augmented, and the level of serum high-density lipoprotein-cholesterol was lessened in myocardial infarcted rats. Further, the activity/levels of liver 3-hydroxy-3-methylglutaryl-coenzyme A reductase and plasma thiobarbituric acid reactive substances were amplified and the activity/levels of heart glutathione -S- transferase, vitamin C, and vitamin E were lessened by isoproterenol. A down-regulated expression of liver sterol regulatory element-binding protein-2 and liver low-density lipoprotein-receptor genes was observed by a reverse transcription-polymerase chain reaction study. Moreover, histopathology of Sudan III staining revealed an accumulation of fats in the heart of isoproterenol-induced rats. Nevertheless, β-caryophyllene pre-and co-treatment blocked alterations in all the parameters examined in isoproterenol-induced rats and inhibited the risk of MI. Moreover, the in vitro study revealed the potent free radical scavenging and antioxidant effects of β-caryophyllene. β-Caryophyllene's antioxidant and anti-hyperlipidemic properties are the possible mechanisms for the observed protective effects in this investigation.

A byproduct from the Valles Calchaquíes vineyards (Argentina) rich in phenolic compounds: a tool against endemic Leishmania dissemination

Vineyard-derived pomace is a byproduct of the wine industry that can have a negative impact on the environment if it is only disposed of or used as a fertilizer. Owing to its polyphenol content, grape pomace is an alternative to biocontrol undesirable microorganisms. In the present study, we characterized the phenolic composition of red and white grape pomace from Valles Calchaquíes, Argentina, and explored its activity against Leishmania (Leishmania) amazonensis, an etiological agent of American tegumentary leishmaniasis, a neglected endemic disease in northern Argentina. Red and white pomace extracts similarly reduced Leishmania viability after a 48-h treatment, with the fractions containing a higher proportion of phenolic compounds being more active. Both extracts stimulated ATPase activity on the parasite plasma membranes, with white grape pomace having a stronger effect than red grape pomace. In addition, the extracts displayed fairly good anticholinesterase activity, which may have contributed to their anti-Leishmania activity. These results reinforce the potential applicability of grape pomace as an antimicrobial agent for the development of biopesticides.

Cobalt-mediated oxidative DNA damage and its prevention by polyphenol antioxidants

Although cobalt is a required nutrient, it is toxic due to its ability to generate reactive oxygen species (ROS) and damage DNA. ROS generation by Co²⁺ often has been compared to that of Fe²⁺ or Cu⁺, disregarding the reduction potential differences among these metal ions. In plasmid DNA damage studies, a maximum of 15% DNA damage is observed with Co²⁺/H₂O₂ treatment (up to 50 μM and 400 μM, respectively) significantly lower than the 90% damage observed for Fe²⁺/H₂O₂ or Cu⁺/H₂O₂ treatment. However, when ascorbate is added to the Co²⁺/H₂O₂ system, a synergistic effect results in 90% DNA damage. DNA damage by Fe²⁺/H₂O₂ can be prevented by polyphenol antioxidants, but polyphenols both prevent and promote DNA damage by Cu⁺/H₂O₂. When tested for cobalt-mediated DNA damage affects, eight of ten polyphenols (epicatechin gallate, epigallocatechin gallate, propyl gallate, gallic acid, methyl-3,4,5-trihydroxybenzoate, methyl-4,5-dihydroxybenzoate, protocatechuic acid, and epicatechin) prevent cobalt-mediated DNA damage with IC₅₀ values of 1.3 to 27 μM and two (epigallocatechin and vanillic acid) prevent little to no DNA damage. EPR studies demonstrate cobalt-mediated formation of ^•OH, O₂^•-, and ^•OOH, but not ¹O₂ in the presence of H₂O₂ and ascorbate. Epigallocatechin gallate and methyl-4,5-dihydroxybenzoate significantly reduce ROS generated by Co²⁺/H₂O₂/ascorbate, consistent with their prevention of cobalt-mediated DNA damage. Thus, while cobalt, iron, and copper are all d-block metal ions, cobalt ROS generation and its prevention is significantly different from that of iron and copper.

Co-administration of Pterocarpus marsupium Extract and Glibenclamide Exhibits Better Effects in Regulating Hyperglycemia and Associated Changes in Alloxan-induced Diabetic Mice

BACKGROUND

Diabetes mellitus (DM) is a well-known global metabolic disorder. For its treatment, glibenclamide (GLB) is very often prescribed. However, herbal drugs are considered effective and better alternatives due to their low risk of side effects. This study was conducted to determine the combined effects of GLB and Pterocarpus marsupium (PM, a commonly available Indian herb) extract for the effective and safe treatment of hyperglycemia in the mouse model.

METHODS

Healthy adult male mice were distributed into five groups (n=7 in each group). Group I acted as the control, whereas groups II, III, IV, and V were considered experimental groups which received a single dosage (150 mg/kg body weight) of alloxan (ALX) intraperitoneally (i.p.). In addition, groups III, IV, and V received a pre-standardized dose of GLB (500 μg/kg body weight), PM extract (150 mg/kg body weight), and GLB+PM, respectively, at the same doses as used in individual treatment, after the seventh day of ALX administration for 15 days and the alterations in different DM related parameters were evaluated.

RESULTS

ALX-induced hyperglycemia and other adverse effects were nearly normalized by GLB and PM co-treatment as evidenced by marked suppression in glucose, triglyceride, total-cholesterol, lipid-peroxidation, and lipid-hydroperoxides with an increase in antioxidants status and liver glycogen content. The positive effects were more pronounced when both GLB and PM were given, as compared to that of either of the drugs, administered alone. Liver ultra-structure, analyzed through histology and transmission electron microscopy revealed normalization of the ALX-induced damaged hepatocytes. The presence of epicatechin, the major phytoconstituent of the PM extract, as confirmed by high-performance liquid chromatography (HPLC), is responsible for its antioxidative and glucose-lowering activities.

CONCLUSION

These findings reveal that PM, along with GLB, exhibits synergistic and better effects than the individual drug in regulating hyperglycemia and associated changes in alloxan-induced mice.

Theaflavin Chemistry and Its Health Benefits

Huge epidemiological and clinical studies have confirmed that black tea is a rich source of health-promoting ingredients, such as catechins and theaflavins (TFs). Furthermore, TF derivatives mainly include theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3'-gallate (TF2B), and theaflavin-3,3'-digallate (TF3). All of these TFs exhibit extensive usages in pharmaceutics, foods, and traditional medication systems. Various indepth studies reported that how TFs modulates health effects in cellular and molecular mechanisms. The available literature regarding the pharmacological activities of TFs has revealed that TF3 has remarkable anti-inflammatory, antioxidant, anticancer, antiobesity, antiosteoporotic, and antimicrobial properties, thus posing significant effects on human health. The current manuscript summarizes both the chemistry and various pharmacological effects of TFs on human health, lifestyle or aging associated diseases, and populations of gut microbiota. Furthermore, the biological potential of TFs has also been focused to provide a deeper understanding of its mechanism of action.

Enhancing in vitro oocyte maturation competence and embryo development in farm animals: roles of vitamin-based antioxidants – a review

Oocyte/embryo in vitro culture is one of the most important assisted reproductive technologies used as a tool for maintaining genetic resources biodiversity and the inheritance of valuable genetic resources through generations. The success of such processes affects the final goal of the in vitro culture, getting viable and healthy offspring. In common in vitro oocyte maturation and/or embryo development techniques, the development of oocytes/embryos is carried out at 5% carbon dioxide and roughly 20% atmosphere-borne oxygen ratios in cell culture incubators due to their reduced cost in comparison with low atmospheric oxygen-tension incubators. These conditions are usually accompanying by the emergence of reactive oxygen species (ROS), which can extremely damage cell membrane integrity and other vital cellular organelles, as well as genetic material. The present review mainly focuses on the antioxidant roles of different vitamins on in vitro oocyte maturation competence and embryo development in farm animals. Because, the conditions of in vitro embryo production (IVEP) are usually accompanying by the emergence of reactive oxygen species (ROS), which can extremely damage cell membrane integrity and other vital cellular organelles as well as genetic material. The use of antioxidant agents may prevent the extreme augmentation of ROS generation and enhance in vitro matured oocyte competence and embryo development. Therefore, this review aimed to provide an updated outline of the impact of antioxidant vitamin (Vit) supplementations during in vitro maturation (IVM) and in vitro fertilization (IVF) on oocyte maturation and consequent embryo development, in various domestic animal species. Thus, the enrichment of the culture media with antioxidant agents may prevent and neutralize the extreme augmentation of ROS generation and enhance the in vitro embryo production (IVEP) outcomes.

Study on mechanism of low bioavailability of black tea theaflavins by using Caco-2 cell monolayer

This study aimed to clarify the bioavailability mechanism of theaflavins by using the Caco-2 monolayer in vitro model. Prior to the transport of theaflavin (TF), theaflavin-3-gallate (TF3G), theaflavin-3'-gallate (TF3'G), and theaflavin-3, 3'-digallate (TFDG), we found the cytotoxicity of theaflavins was in the order of TF3'G > TFDG > TF3G > TF, suggesting the galloyl moiety enhances the cytotoxicity of theaflavins. Meantime, the galloyl moiety made theaflavins unstable, with the stability in the order of TF > TFDG > TF3G/TF3'G. Four theaflavins showed poor bioavailability with the P_app values ranging from 0.44 × 10^-7 to 3.64 × 10^-7 cm/s in the absorptive transport. All the theaflavins showed an efflux ratio of over 1.24. And it is further confirmed that P-glycoprotein (P-gp), multidrug resistance associated proteins (MRPs) and breast cancer resistance protein (BCRP) were all shown to contribute to the efflux transport of four theaflavins, with P-gp playing the most important role, followed by MRPs and BCRP. Moreover, theaflavins increased the expression of P-gp, MRP1, MPR3, and BCRP while decreased the expression of MRP2 at the transcription and translation levels. Additionally, the gallated theaflavins were degraded into simple theaflavins and gallic acids when transported through Caco-2 monolayers. Overall, the structural instability, efflux transporters, and cell metabolism were all responsible for the low bioavailability of four theaflavins in Caco-2 monolayers.

Cellular Defensive Mechanisms of Tea Polyphenols: Structure-Activity Relationship

Tea is particularly rich in polyphenols, including catechins and theaflavins, thearubigins, flavonols, and phenolic acids, which are believed to contribute to the health benefits of tea. The health-promoting effects of tea polyphenols are believed to be related to their cellular defensive properties. This review is intended to briefly summarize the relationship between the chemical structures of tea polyphenols and their biological activities. Tea polyphenols appear as direct antioxidants by scavenging reactive oxygen/nitrogen species; chelating transition metals; and inhibiting lipid, protein, and DNA oxidations. They also act directly by suppressing “pro-oxidant” enzymes, inducing endogenous antioxidants, and cooperating with vitamins. Moreover, tea polyphenols regulate cellular signaling transduction pathways, importantly contributing to the prevention of chronic diseases and the promotion of physiological functions. Apparently, the features in the chemical structures of tea polyphenols are closely associated with their antioxidant potentials.

Evaluation of antityrosinase activity and mechanism, antioxidation, and UV filter properties of theaflavin

Tyrosinase is a key metalloenzyme for the biosynthesis of melanin that plays a critical role in the prevention of skin damage caused by ultraviolet (UV) radiation. However, the overproduction of melanin may cause a variety of skin diseases. Due to the toxicity and inefficiency of existing tyrosinase inhibitors, it is urgent to identify safe and potent alternatives from natural sources. Theaflavin, a single-component extracted from black tea, has been found to possess a variety of pharmacological activities. Herein, the inhibition kinetics of theaflavin on tyrosinase and inhibitory mechanism were determined using spectroscopy, molecular docking, and zebrafish model. The results showed that theaflavin inhibited the diphenolase activity of tyrosinase in a reversible mixed type manner with IC₅₀ of 229.75 μmol/L and hindered the synthesis of melanin in zebrafish. This may be due to the formation of eight hydrogen bonds and hydrophobic effects between theaflavin and tyrosinase according to the results of molecular docking. To study the possible effects on the prevention of free radical-mediated skin cancer and photoaging caused by UV radiation, the antioxidation and UV filter properties of theaflavin were further verified. This study demonstrates that theaflavin is a potential multifunctional compound that can be used in cosmetic and medicinal products.

Antioxidant activity of curcumin protects against the radiation-induced micronuclei formation in cultured human peripheral blood lymphocytes exposed to various doses of γ-Radiation

PURPOSE

Ionizing radiations trigger the formation of free radicals that damage DNA and cause cell death. DNA damage may be simply evaluated by micronucleus assay and the pharmacophores that impede free radicals could effectively reduce the DNA damage initiated by irradiation. Therefore, it was desired to determine the capacity of curcumin to alleviate micronuclei formation in human peripheral blood lymphocytes (HPBLs) exposed to 0-4 Gy of γ-radiation.

MATERIALS AND METHODS

HPBLs were exposed to 3 Gy after 30 minutes of 0.125, 0.25, 0.5, 1, 2, 5, 10, 20 or 50 µg/mL curcumin treatment or with 0.5 μg/mL curcumin 30 minutes early to 0, 0.5, 1, 2, 3 or 4 Gy 60Co γ-irradiation. Cytokinesis of HPBLs was blocked by cytochalasin B and micronuclei scored. The ability of curcumin to suppress free radical induction in vitro was determined by standard methods.

RESULTS

HPBLs treated with different concentrations of curcumin before 3 Gy irradiation alleviated the micronuclei formation depending on curcumin concentration and the lowest micronuclei were detected at 0.5 µg/mL curcumin when compared to 3 Gy irradiation alone. Increasing curcumin concentration caused a gradual rise in micronuclei, and the significant increases were detected at 10-50 µg/mL curcumin than 3 Gy irradiation alone. Irradiation of HPBLs to different doses of γ-rays caused a significant rise in micronuclei depending on radiation dose, whereas HPBLs treated with 0.5 µg/mL curcumin 30 minutes before irradiation to different doses of γ-rays significantly reduced frequencies of HPBLs with one, two, or more micronuclei. Curcumin treatment inhibited the formation of hydroxyl (OH), 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 2,2'-diphenyl-1-picrylhydrazyl (DPPH), and (nitric oxide) NO free radicals in a concentration-related way.

CONCLUSIONS

Curcumin when treated at a dose of 0.5 μg/mL attenuated micronuclei formation after γ-irradiation by inhibiting the formation of radiation-induced free radicals.

Black Tea Theaflavin Detoxifies Metabolic Toxins in the Intestinal Tract of Mice

SCOPE

This study is to determine the in vivo efficacy of black tea theaflavin (TF) to detoxify two metabolic toxins, ammonia and methylglyoxal (MGO), in mice METHODS AND RESULTS: Under in vitro conditions, TF is able to react with ammonia, MGO, and hydrogen peroxide to produce its aminated, MGO conjugated, and oxidized products, respectively. In TF-treated mice, the aminated TF, the MGO conjugates of TF and aminated TF, and the oxidized TF are searched using LC-MS/MS. The results provide the first in vivo evidence that the unabsorbed TF is able to trap ammonia to form the aminated TF; furthermore, both TF and the aminated TF have the capacity to trap MGO to generate the corresponding mono-MGO conjugates. Moreover, TF is oxidized to dehydrotheaflavin, which underwent further amination in the gut. By exposing TF to germ-free (GF) mice and conventionalized mice (GF mice colonized with specific-pathogen-free microbiota), the gut microbiota is demonstrated to facilitate the amination and MGO conjugation of TF.

CONCLUSION

TF has the capacity to remove the endogenous metabolic toxins through oxidation, amination, and MGO conjugation in the intestinal tract, which can potentially explain why TF still generates in vivo efficacy while showing a poor systematic bioavailability.

α-Bisabolol, a Dietary Bioactive Phytochemical Attenuates Dopaminergic Neurodegeneration through Modulation of Oxidative Stress, Neuroinflammation and Apoptosis in Rotenone-Induced Rat Model of Parkinson's disease

Rotenone (ROT), a plant-derived pesticide is a well-known environmental neurotoxin associated with causation of Parkinson’s disease (PD). ROT impairs mitochondrial dysfunction being mitochondrial complex-I (MC-1) inhibitor and perturbs antioxidant-oxidant balance that contributes to the onset and development of neuroinflammation and neurodegeneration in PD. Due to the scarcity of agents to prevent the disease or to cure or halt the progression of symptoms of PD, the focus is on exploring agents from naturally occurring dietary phytochemicals. Among numerous phytochemicals, α-Bisabolol (BSB), natural monocyclic sesquiterpene alcohol found in many ornamental flowers and edible plants garnered attention due to its potent pharmacological properties and therapeutic potential. Therefore, the present study investigated the neuroprotective effects of BSB in a rat model of ROT-induced dopaminergic neurodegeneration, a pathogenic feature of PD and underlying mechanism targeting oxidative stress, inflammation and apoptosis. BSB treatment significantly prevented ROT-induced loss of dopaminergic neurons and fibers in the substantia nigra and striatum respectively. BSB treatment also attenuated ROT-induced oxidative stress evidenced by inhibition of MDA formation and GSH depletion as well as improvement in antioxidant enzymes, SOD and catalase. BSB treatment also attenuated ROT-induced activation of the glial cells as well as the induction and release of proinflammatory cytokines (IL-1β, IL-6 and TNF-α) and inflammatory mediators (iNOS and COX-2) in the striatum. In addition to countering oxidative stress and inflammation, BSB also attenuated apoptosis of dopaminergic neurons by attenuating downregulation of anti-apoptotic protein Bcl-2 and upregulation of pro-apoptotic proteins Bax, cleaved caspases-3 and 9. Further, BSB was observed to attenuate mitochondrial dysfunction by inhibiting mitochondrial lipid peroxidation, cytochrome-C release and reinstates the levels/activity of ATP and MC-I. The findings of the study demonstrate that BSB treatment salvaged dopaminergic neurons, attenuated microglia and astrocyte activation, induction of inflammatory mediators, proinflammatory cytokines and reduced the expression of pro-apoptotic markers. The in vitro study on ABTS radical revealed the antioxidant potential of BSB. The results of the present study are clearly suggestive of the neuroprotective effects of BSB through antioxidant, anti-inflammatory and anti-apoptotic properties in ROT-induced model of PD.

Modifying effects of leaf litter extracts from invasive versus native tree species on copper-induced responses in Lemna minor

Invasive plant species tend to migrate from their native habitats under favourable climatic conditions; therefore, trophic and other relationships in ecosystems are changing. To investigate the effect of natural organic matter derived from native Alnus glutinosa tree species and from invasive in Lithuania Acer negundo tree species on copper toxicity in Lemna minor, we analysed the dynamics of Cu binding in aqueous leaf litter extracts (LLE) and plant accumulation, morphophysiological parameters, and antioxidative response. The results revealed that A. glutinosa LLE contained polyphenols (49 mg pyrogallol acid equivalent (PAE)/g DM) and tannins (7.5 mg PAE/g DM), while A. negundo LLE contained only polyphenols (23 mg PAE/g DM). The ability of LLE to bind Cu increased rapidly over 1.5-3 h to 61% and 49% of the total Cu concentration (6.0 ± 0.9 mg/L), respectively for A. glutinosa (AG) and A. negundo (AN), then remained relatively stable until 48 h. At the same time, L. minor accumulated 384, 241 or 188 µg Cu/g FW when plants were exposed to Cu (100 µM CuSO4), Cu with 100 mg/L dissolved organic carbon (DOC) from either AG LLE or AN LLE, accordingly. Catalase (CAT) and guaiacol peroxidase (POD) played a dominant role in hydrogen peroxide scavenging when plants were exposed to Cu and 10 or 100 mg/L DOCAG mixtures in both the first (up to 6h) and the second (6-48 h) response phases. Due to functioning of oxidative stress enzymes, the levels of the lipid peroxidation product malondialdehyde (MDA) reduced in concentration-dependent manner, compared to Cu treatment. When combining Cu and DOCAN treatments, the most sensitive enzymes were POD, ascorbate peroxidase and glutathione reductase. Their activities collectively with CAT were sufficient to reduce MDA levels to Cu-induced in the initial, but not the second response phase. These data suggest that leaf litter extracts of different phenolic compositions elicited different antioxidant response profiles resulting in different reductions of Cu stress, thus effecting L. minor frond and root development observed after seven days. The complex data from this study may be useful in modelling the response of the aquatic ecosystem to a changing environment.

Effects of Infusion and Storage on Antioxidant Activity and Total Phenolic Content of Black Tea

This study determined antioxidant activity in terms of the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging ability and total phenolic content of black tea under different infusion and storage conditions. High performance liquid chromatography analysis identified caffeine, (−)-epigallocatechin, (−)-epicatechin-3-gallate, (−)-epigallocatechin-3-gallate and (−)-gallocatechin-3-gallate in the tea sample. The water–tea leaves weight ratio did not affect the DPPH scavenging ability. However, infusion temperature affected the DPPH scavenging activity and the total phenolic content. In the present study, the 50% inhibitory concentrations (IC50) for DPPH of black tea infused at 60 to 100 °C ranged from 100.0 ± 13.7 to 28.4 ± 4.8 μg/mL. The total phenolic content of black tea steeped at 60 to 100 °C ranged from 50.4 ± 5.2 to 178.6 ± 16.4 mg gallic acid equivalent/g dry leaf. Black tea exhibited increased antioxidant activity when the infusion temperature was increased. Regarding short-term storage, the DPPH scavenging ability and total phenolic content of black tea did not significantly change within 15 days. This result was consistent for storage temperatures of 4, 9, and 25 °C.

Issues surrounding consumer trust and acceptance of existing and emerging food processing technologies

The purpose of food processing today is to make food safer, more nutritious and tastier, and to increase storage life. Consumers have a lack of trust in the way food is produced, formulated and processed, particularly with possible contaminants or chemical residues from production. Food manufacturers are not seen as being highly trusted sources. This may partly result from manufacturers' reluctance to share all information and to protect intellectual property via patents and thus maintain a competitive edge. There is a need to inform the consumer better about what operations the involved ingredients are subjected to and why. Various ways of food processing are reviewed. New food processing technologies face challenges when introduced and factors influencing consumers' and other stakeholders' acceptance should be part of decision-making process when adopting new technologies. Consumers' perception of risks is not the same as the risk assessment made by experts. A few specific cases are being discussed to further highlight the multiplicity of factors that may contribute to the development of a certain consumer perception about a product or a class of products. This is also linked to the emergence of certain terminologies that are associated with an increasingly negative perception of the processing of foods. We recommend more transparency on food formulation and food processing to restore consumer trust, which enables to take the advantage of the benefits different processing methods offer. Food manufacturers must make an effort to let consumers know how their food is being processed within the walls of the factory and highlight the benefits vis-à-vis preparing foods in a domestic environment.

Molecular Mechanisms That Define Redox Balance Function in Pathogen-Host Interactions-Is There a Role for Dietary Bioactive Polyphenols?

To ensure a functional immune system, the mammalian host must detect and respond to the presence of pathogenic bacteria during infection. This is accomplished in part by generating reactive oxygen species (ROS) that target invading bacteria; a process that is facilitated by NADPH oxidase upregulation. Thus, bacterial pathogens must overcome the oxidative burst produced by the host innate immune cells in order to survive and proliferate. In this way, pathogenic bacteria develop virulence, which is related to the affinity to secrete effector proteins against host ROS in order to facilitate microbial survival in the host cell. These effectors scavenge the host generated ROS directly, or alternatively, manipulate host cell signaling mechanisms designed to benefit pathogen survival. The redox-balance of the host is important for the regulation of cell signaling activities that include mitogen-activated protein kinase (MAPK), p21-activated kinase (PAK), phosphatidylinositol 3-kinase (PI3K)/Akt, and nuclear factor κB (NF-κB) pathways. An understanding of the function of pathogenic effectors to divert host cell signaling is important to ascertain the mechanisms underlying pathogen virulence and the eventual host–pathogen relationship. Herein, we examine the effectors produced by the microbial secretion system, placing emphasis on how they target molecular signaling mechanisms involved in a host immune response. Moreover, we discuss the potential impact of bioactive polyphenols in modulating these molecular interactions that will ultimately influence pathogen virulence.

Therapeutic potential of natural compounds in inflammation and chronic venous insufficiency

The term varicose vein refers to the twisted and swollen vein visible under the skin surface which occurs most commonly in the leg. Epidemiological studies report a varying percentage of incidences from 2 to 56% in men and <1-60% in women. Venous insufficiency is most often caused by the damage to the valves and walls of the veins. The mechanism of varicose vein formation is complex. It is, however, based on hypotensive blood vessels, hypoxia, and other mechanisms associated with inflammation. This work describes mechanisms related to the formation and development of the varicose vein. It discusses risk factors, pathogenesis of chronic venous disease, markers of the epithelial and leukocyte activation, state of hypoxia and inflammation, reactive oxygen species (ROS) generation, and oxidative stress. Additionally, this paper describes substances of plant origin used in the treatment of venous insufficiency. It also considers the structure of the molecules, their properties, and their mechanisms of action, the structure-activity relationship and chemical properties of flavonoids and other substances. The flavonoids include quercetin derivatives, micronized purified flavonoid fraction (Daflon), natural pine bark extract (Pycnogenol), and others such as triterpene saponine, extracts from Ruscus aculeatus and Centella asiatica, Ginkgo biloba extract, coumarin dereivatives that are used in chronic venous insufficiency. Flavonoids are natural substances found in plants, including fruits, vegetables, flowers, and others. They are important to the circulatory system and critical to blood vessels and the blood flow. Additionally, they have antioxidant, antiinflammatory properties.

Antioxidant capacity of phenolics in Camellia nitidissima Chi flowers and their identification by HPLC Triple TOF MS/MS

Camellia nitidissima Chi (CNC) is a valuable medicinal and edible plant in China. In this study, CNC flowers were extracted with 95% ethanol, then partitioned into dichloromethane, ethyl acetate, n-butanol, and water fractions, with the antioxidant capacity of flavonoids and other phytochemicals in CNC flowers investigated for the first time. Results showed that the ethyl acetate fraction exhibited the strongest antioxidant capacity and highest total phenolic content (TPC) compared with the other fractions. Furthermore, in the ethyl acetate fraction, the 50% effective concentrations (EC₅₀) of ABTS⁺ and DPPH radical scavenging activities were 64.24 ± 1.80 and 78.80 ± 0.34 μg/mL, respectively, and the ferric reducing antioxidant power (FRAP) was 801.49 ± 2.30 μM FeSO₄ at 1,000 μg/mL. Pearson’s correlation coefficients and principal component analyses (PCA) for the TPC and antioxidant capacity of the five fractions indicated that the phenolic compounds were the major antioxidant constituents in the flowers. To exploit the antioxidants in CNC flowers, 21 phenolic compounds in the ethanolic extract fraction were identified by HPLC Triple TOF MS/MS, next, 12 flavonoids were isolated and elucidated, of which compounds 1–5 showed potent antioxidant capacity. In addition, the potential structure-activity relationship among these 12 flavonoids showed that (1) the o-catechol group in the B-ring was primarily responsible for the antioxidant capacity of flavonoids and (2) steric hindrance, produced by glycosides and other groups, could reduce the antioxidant capacity of the flavonoids.

Neuroprotective Effects and Mechanisms of Tea Bioactive Components in Neurodegenerative Diseases

As the population ages, neurodegenerative diseases such as Parkinson's disease (PD) and Alzheimer's disease (AD) impose a heavy burden on society and families. The pathogeneses of PD and AD are complex. There are no radical cures for the diseases, and existing therapeutic agents for PD and AD have diverse side effects. Tea contains many bioactive components such as polyphenols, theanine, caffeine, and theaflavins. Some investigations of epidemiology have demonstrated that drinking tea can decrease the risk of PD and AD. Tea polyphenols can lower the morbidity of PD and AD by reducing oxidative stress and regulating signaling pathways and metal chelation. Theanine can inhibit the glutamate receptors and regulate the extracellular concentration of glutamine, presenting neuroprotective effects. Additionally, the neuroprotective mechanisms of caffeine and theaflavins may contribute to the ability to antagonize the adenosine receptor A2AR and the antioxidant properties, respectively. Thus, tea bioactive components might be useful for neuronal degeneration treatment in the future. In the present paper, the neuro protection and the mechanisms of tea and its bioactive components are reviewed. Moreover, the potential challenges and future work are also discussed.

Beneficial effects of tyrosol on altered glycoprotein components in streptozotocin-induced diabetic rats

CONTEXT

Olive oil is the major source of tyrosol which is a natural phenolic antioxidant. Olive oil constitutes a major component of the Mediterranean diet that is linked to a reduced incidence of chronic diseases.

OBJECTIVE

This study evaluates the effects of tyrosol on altered glycoprotein components in streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

Diabetes mellitus was induced in male Wistar rats by streptozotocin (40 mg/kg body weight). These rats were administered tyrosol (20 mg/kg body weight) and glibenclamide (600 μg/kg body weight) orally daily for 45 days. Plasma glucose, plasma insulin, glycoprotein components such as hexose, hexosamine, sialic acid and fucose in the plasma, liver and kidney, and histopathogy of tissues were analyzed.

RESULTS

Diabetic rats revealed significant (p < 0.05) increase in the levels of glucose, hexose, hexosamine, sialic acid and fucose (277.17, 152.45, 100.43, 79.69 and 49.29 mg/dL) in the plasma; decrease in the levels of palsma insulin (6.12 μU/mL) and sialic acid (4.36 and 5.03 mg/g) in the liver and kidney; significant (p < 0.05) increase in hexose (49.33 and 46.82 mg/g), hexosamine (22.68 and 33.20 mg/g) and fucose (31.63 and 32.44 mg/g) in the liver and kidney. Further, periodic acid-Schiff staining of tissues revealed positive-stain accumulation in diabetic rats. Tyrosol treatment showed significant (p < 0.05) effects on all the biochemical parameters and histopathology studied in streptozotocin- nduced diabetic rats. Also, the in vitro study revealed the antioxidant effect of tyrosol.

DISCUSSION AND CONCLUSIONS

Thus, tyrosol protects streptozotocin-induced diabetic rats from the altered glycoprotein components. Further, this study can be extrapolated to humans.

Molecular Mechanisms and Pathways as Targets for Cancer Prevention and Progression with Dietary Compounds

A unique feature of bioactive food ingredients is their broad antioxidant function. Antioxidants having a wide spectrum of chemical structure and activity beyond basic nutrition; display different health benefits by the prevention and progression of chronic diseases. Functional food components are capable of enhancing the natural antioxidant defense system by scavenging reactive oxygen and nitrogen species, protecting and repairing DNA damage, as well as modulating the signal transduction pathways and gene expression. Major pathways affected by bioactive food ingredients include the pro-inflammatory pathways regulated by nuclear factor kappa B (NF-κB), as well as those associated with cytokines and chemokines. The present review summarizes the importance of plant bioactives and their roles in the regulation of inflammatory pathways. Bioactives influence several physiological processes such as gene expression, cell cycle regulation, cell proliferation, cell migration, etc., resulting in cancer prevention. Cancer initiation is associated with changes in metabolic pathways such as glucose metabolism, and the effect of bioactives in normalizing this process has been provided. Initiation and progression of inflammatory bowel diseases (IBD) which increase the chances of developing of colorectal cancers can be downregulated by plant bioactives. Several aspects of the potential roles of microRNAs and epigenetic modifications in the development of cancers have also been presented.

A new, simplified model for the estimation of polyphenol oxidation potentials based on the number of OH groups

We present a new and simpler regression model for the estimation of the first oxidation potentials (Ep1) of flavonoids based on the number of phenolic, alcoholic, and carboxylic OH groups. In the regression we included the Ep1 of 12 polyphenols (mostly flavonols and catechins) that were measured in our laboratory at pH 3. The model yielded r=0.986 and SE=0.040. Later successive inclusions of previously reported Ep values into the regression model, 7 at pH 3, the model (N=19) yielded r=0.980, SE=0.046 and 19 at pH 7 the model (N=38), yielded r=0.985, SE=0.044.

Hepatoprotective potential of Fagonia olivieri DC. against acetaminophen induced toxicity in rat

BACKGROUND

Fagonia olivieri (DC) being used for the treatment of diabetes, cancer, fever and claimed to be effective in many other stress related disorders. In this study we have evaluated the F. olivieri whole methanol extract and its derived fractions for various in vitro and in vivo antioxidant studies.

METHODS

The crude methanol extract of the whole plant of F. olivieri (FOM) and its derived fractions; n-hexane (FOH), chloroform (FOC), ethyl acetate (FOE), n-butanol (FOB) and aqueous (FOA) were evaluated for the total phenolic and flavonoid content and in vitro antioxidant abilities. The antioxidant effect of FOM was determined by acetaminophen-induced hepatotoxicity in Sprague-Dawley (Rattus novergicus) male rats. The methanol/fractions were also analysed by HPLC analysis for the presence of polyphenolics.

RESULTS

The total phenolic content of the samples ranged from 19.3 ± 0.529 to 106.2 ± 0.892 mg GAE/g extract while total flavonoid content 16.2 ± 0.881 to 50.1 ± 1.764 mg RTE/g extract, respectively. FOA showed highest radical scavenging activity for DPPH (IC50 = 55.2 ± 1.212 μg/ml), ABTS (IC50 = 90.2 ± 1.232 μg/ml) superoxide (IC50 = 37.1 ± 0.643 μg/ml) and for H2O2 (IC50 = 64 ± 1.463 μg/ml). FOE exhibited the highest antioxidant activities for phosphomolybdenum (IC50 = 78.2 ± 0.883 μg/ml) and for hydroxyl radical scavenging (IC50 = 82 ± 2.603 μg/ml). HPLC analysis of FOM and its derived fractions showed the presence of rutin, catechin and gallic acid. Elevated levels of AST, ALT, ALP, LDH and lipid profile in serum and lipid peroxidation and DNA damages in liver; while decreased activity level of CAT, SOD, GSH-Px, GR and reduced glutathione (GSH) concentration induced with acetaminophen in rat were reverted towards the control group with co-administration of FOM.

CONCLUSION

Our results showed that F. olivieri is a potential source of natural antioxidants, which justifies its use in folklore medicine.

Neuroprotective Effects of Theaflavins Against Oxidative Stress-Induced Apoptosis in PC12 Cells

Oxidative stress can induce neuronal apoptosis via the production of superoxide and hydroxyl radicals. This process is as a major pathogenic mechanism in neurodegenerative disorders. In this study, we aimed to clarify whether theaflavins protect PC12 cells from oxidative stress damage induced by H₂O₂. A cell model of PC12 cells undergoing oxidative stress was created by exposing cells to 200 μM H₂O₂ in the presence or absence of varying concentrations of theaflavins (5, 10, and 20 μM). Cell viability was monitored using the MTT assay and Hoechst 33258 staining, showing that 10 μM theaflavins enhanced cell survival following 200 μM H₂O₂ induced toxicity and increased cell viability by approximately 40 %. Additionally, we measured levels of intracellular reactive oxygen species (ROS) and antioxidant enzyme activity. This suggested that the neuroprotective effect of theaflavins against oxidative stress in PC12 cells is derived from suppression of oxidant enzyme activity. Furthermore, Western blot analyses indicated that theaflavins downregulated the ratio of pro-apoptosis/anti-apoptosis proteins Bax/Bcl-2. Theaflavins also downregulated the expression of caspase-3 compared with a H₂O₂-treated group that had not been treated with theaflavins. Interestingly, this is the first study to report that the four main components of theaflavins found in black tea can protect neural cells (PC12) from apoptosis induced by H₂O₂. These findings provide the foundations for a new field of using theaflavins or its source, black tea, in the treatment of neurodegenerative diseases caused by oxidative stress.

Antimicrobial, antioxidant and anticancer activity of biogenic silver nanoparticles – an experimental report

In the present study, use of a Helicteres isora stem bark extract for the biosynthesis of AgNPs is described.

Identification of small molecules that disrupt signaling between ABL and its positive regulator RIN1

Constitutively active BCR-ABL kinase fusions are causative mutations in the pathogenesis of hematopoietic neoplasias including chronic myelogenous leukemia (CML). Although these fusions have been successfully targeted with kinase inhibitors, drug-resistance and relapse continue to limit long-term survival, highlighting the need for continued innovative drug discovery. We developed a time-resolved Förster resonance energy transfer (TR-FRET) -based assay to identify compounds that disrupt stimulation of the ABL kinase by blocking its ability to bind the positive regulator RIN1. This assay was used in a high throughput screen (HTS) of two small molecule libraries totaling 444,743 compounds. 708 confirmed hits were counter-screened to eliminate off-target inhibitors and reanalyzed to prioritize compounds with IC₅₀ values below 10 μM. The CML cell line K562 was then used to identify five compounds that decrease MAPK1/3 phosphorylation, which we determined to be an indicator of RIN1-dependent ABL signaling. One of these compounds is a thiadiazole, and the other four are structurally related acyl piperidine amides. Notably, these five compounds lower cellular BCR-ABL1 kinase activity by blocking a positive regulatory interaction rather than directly inhibiting ABL catalytic function.

Free radicals, natural antioxidants, and their reaction mechanisms

The normal biochemical reactions in our body, increased exposure to the environment, and higher levels of dietary xenobiotic's result in the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS).

Preventive effects of zingerone on altered lipid peroxides and nonenzymatic antioxidants in the circulation of isoproterenol-induced myocardial infarcted rats

The present study was designed to evaluate the preventive effects of zingerone on circulatory lipid peroxides and nonenzymatic antioxidants in isoproterenol-induced myocardial infarcted rats. Rats were pretreated with zingerone (6 mg/kg body weight) daily for a period of 14 days and were then induced myocardial infarction with isoproterenol (100 mg/kg body weight) on 15th and 16th day. Increased intensities of serum lactate dehydrogenase isoenzymes 1 and 2 bands enhanced plasma lipid peroxidation products and lowered nonenzymatic antioxidant system were noted in isoproterenol-induced rats. Pretreatment with zingerone daily for 14 days revealed significant preventive effects on the electrophoretic and biochemical parameters evaluated in isoproterenol-induced rats. Furthermore, the in vitro study confirmed the potent antioxidant activity of zingerone. The results of our study showed that zingerone protected the rat's heart against isoproterenol-induced myocardial infarction by its antioxidant effect.

Production of Hydrogen Peroxide by Polyphenols and Polyphenol-rich Beverages underQuasi-physiological Conditions

To investigate the ability of the production of H(2)O(2) by polyphenols, we incubated various phenolic compounds and natural polyphenols under a quasi-physiological pH and temperature (pH 7.4, 37 degrees C), and then measured the formation of H(2)O(2) by the ferrous ion oxidation-xylenol orange assay. Pyrocatechol, hydroquinone, pyrogallol, 1,2,4-benzenetriol, and polyphenols such as catechins yielded a significant amount of H(2)O(2). We also examined the effects of a metal chelator, pH, and O(2) on the H(2)O(2)-generating property, and the generation of H(2)O(2) by the polyphenol-rich beverages, green tea, black tea, and coffee, was determined. The features of the H(2)O(2)-generating property of green tea, black tea, and coffee were in good agreement with that of phenolic compounds, suggesting that polyphenols are responsible for the generation of H(2)O(2) in beverages. From the results, the possible significances of the H(2)O(2)-generating property of polyphenols for biological systems are discussed.

Diosgenin interferes coronary vasoconstriction and inhibits osteochondrogenic transdifferentiation of aortic VSMC in CRF rats

Cardiovascular dysfunction and vascular calcification is the leading cause of death in chronic renal failure (CRF) patients. This study was designed to evaluate the effect of diosgenin on coronary flow resistance and to address the question whether the previously proven antivascular calcification potential of diosgenin is associated or not with the osteochondrogenic transdifferentiation of vascular smooth muscle cells (VSMC). In this study, CRF in Wistar rats was induced by fed with 0.75% adenine and diosgenin was treated everyday at the dose of 40 mg/kg. Langendorff based isolated heart protocol was employed to analyze the coronary flow resistance. Western blot method was used to explore the phosphorylation dynamics of endothelial nitric oxide synthase (eNOS) at the serine 1177 residue. In addition, cardiac nitric oxide metabolites level also assessed. Quantitative expression of VSMC and osteochondrogenic markers was also evaluated. Antioxidant potential of diosgenin was studied in vitro. The outcome of the present study explores that diosgenin treatment significantly improves the coronary resistance and increased the nitric oxide metabolites level compared with CRF. Further, diosgenin increases the phosphorylation of eNOS (peNOS ser1177). Moreover, diosgenin reduced the aortic expression of osteochondrogenic markers and improved the VSMC phenotype components. Further, diosgenin shows concentration dependent antioxidant potential. In conclusion, this study have proven that diosgenin have enough potential to improve the coronary function and interfere the osteochondrogenic transdifferentiation program of aortic VSMC which supports its antivascular calcification potential.

Synthesis of 4-methyl-N′-(3-alkyl-2r,6c-diarylpiperidin-4-ylidene)-1,2,3-thiadiazole-5-carbohydrazides with antioxidant, antitumor and antimicrobial activities

The structures of the newly synthesized 4-methyl-N′-(3-alkyl-2r,6c-diarylpiperidin-4-ylidene)-1,2,3-thiadiazole-5-carbohydrazide (5a–5l) were confirmed by spectral and elemental analysis.

Antioxidative and radioprotective potential of rutin and quercetin in Swiss albino mice exposed to gamma radiation

The radioprotective potential of bioflavonoid, rutin (RUT) and quercetin (QRT) was investigated in Swiss albino mice exposed to gamma radiation. The radioprotective potential of RUT and QRT was assessed in pre-treatment group of mice followed on radiation-induced changes in glutathione (GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), and lipid peroxidation (LPO) levels were also analyzed. Elevation in the GSH, GST, SOD, CAT, and decreased LPO levels were observed in RUT and QRT pretreated group when compared to the irradiated animals. Furthermore, it was observed that RUT and QRT treatment was found to inhibit various free radicals generated in vitro, viz., 2,2-diphenyl-1-picrylhydrazyl(DPPH), O2, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS)(+), and OH in a concentration-dependent manner. This study clearly demonstrates the free radical scavenging action of RUT and QRT, indicating that it may have its potential as a radioprotective agent. Furthermore, the presence of a phenolic group in RUT and QRT is known to contribute to scavenging the radiation-induced free radicals and inhibition of oxidative stress. Present findings demonstrate the potential of RUT and QRT in mitigating radiation-induced oxidative stress, which may be attributed to the inhibition of radiation-induced decline in the endogenous antioxidant levels and scavenging of radiation-induced free radicals.

(-) Epicatechin prevents alterations in lysosomal glycohydrolases, cathepsins and reduces myocardial infarct size in isoproterenol-induced myocardial infarcted rats

The preventive effects of (-) epicatechin on oxidative stress, cardiac mitochondrial damage, altered membrane bound adenosine triphosphatases and minerals were reported previously in isoproterenol-induced myocardial infarction model. Leakage of lysosomal glycohydrolases and cathepsins play an important role in the pathology of myocardial infarction. This study was aimed to evaluate the preventive effects of (-) epicatechin on alterations in lysosomal glycohydrolases, cathepsins and myocardial infarct size in isoproterenol-induced myocardial infarcted rats. Male albino Wistar rats were pretreated with (-) epicatechin (20mg/kg body weight) daily for a period of 21 days. After the pretreatment period, isoproterenol (100mg/kg body weight) was injected subcutaneously into the rats at an interval of 24h for two days to induce myocardial infarction. The levels of serum cardiac troponin-I and the activities of serum and heart lysosomal enzymes (β-glucuronidase, β-N-acetyl glucosaminidase, β-galactosidase, cathepsin-B and cathepsin-D) were increased significantly (P<0.05) and the activities of β-glucuronidase and cathepsin-D in the heart lysosomal fractions were significantly (P<0.05) decreased in isoproterenol-induced myocardial infarcted rats. The in vitro study revealed the potent antioxidant action of (-) epicatechin. Pretreatment with (-) epicatechin daily for a period of 21 days prevented the leakage of cardiac marker, lysosomal glycohydrolases, cathepsins, and reduced infarct size, thereby protecting the lysosomal membranes in isoproterenol-induced myocardial infarcted rats, by virtue of its membrane stabilizing property.

Antioxidant and antibacterial properties of green, black, and herbal teas of Camellia sinensis

Background:

The role of non-polymeric phenolic (NP) and polymeric tannin (PT) constituents in the antioxidant and antibacterial properties of six brands of green, black, and herbal teas of Camellia sinensis were investigated.

Materials and Methods:

Total phenolic content (TPC) and ascorbic acid equivalent antioxidant capacity (AEAC) were assessed using the Folin-Ciocalteu and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays, respectively. Minimum inhibitory dose (MID) against Gram-positive Micrococcus luteus, Staphylococcus aureus, and Bacillus cereus, and Gram-negative. Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa was assessed using the disc-diffusion method. Teas were extracted with hot water successively three times for one hour each time. The extracts were fractionated using Sephadex LH-20 column chromatography to obtain the NP and PT constituents.

Results:

Extraction yields ranged from 12 to 23%. Yields of NP fractions (70–81%) were much higher than those of PT fractions (1–11%), suggesting that the former are the major tea components. Ranking of antioxidant properties of extracts was green tea>black tea>herbal tea. For all six teas, antioxidant properties of PT fractions were significantly higher than extracts and NP fractions. Extracts and fractions of all six teas showed no activity against the three Gram-negative bacteria. Green teas inhibited all three Gram-positive bacteria with S. aureus being the least susceptible. Black and herbal teas inhibited the growth of M. luteus and B. cereus, but not S. aureus. The most potent were the PT fractions of Boh Cameron Highlands and Ho Yan Hor with MID of 0.01 and 0.03 mg/disc against M. luteus.

Conclusion:

Results suggested that NP constituents are major contributors to the antioxidant and antibacterial properties of teas of C. sinensis. Although PT constituents have stronger antioxidant and antibacterial properties, they constitute only a minor component of the teas.

Antioxidant activities and determination of phenolic compounds isolated from oriental plums (Soldam, Oishiwase and Formosa)

The purposes of this study were to determine phenolic compounds and to evaluate antioxidant activities of plums (Soldam, Oishiwase and Formosa). Soldam contains the highest amount of total phenolics among cultivars (Formosa: 4.0%, Oishiwase: 3.3%, Soldam: 6.4% for total phenolic) as well as the total flavonoids of which constituents were mainly myricetin and anthocyanidin. The antioxidant activities were measured by DPPH, ABTS radical scavenging, and SOD-like activities. The DPPH radical scavenging activity of Korean plum extracts (200 µg/mL) showed more than 43%, and the Soldam turned out to be the highest : ID₅₀ value: 160-177 µg/mL for Formosa and Oishiwase; 58-64 µg/mL for Soldam. The ABTS radical scavenging activity of Korean plum extracts (200 µg/mL) was found to be more than 50%. The SOD-like activity of Korean plum extracts (200 µg/mL) showed more than 70%. Among three kinds of cultivars, Soldam had the highest antioxidant activity. The nitrite scavenging activity of Soldam was 61.5%, which is the highest, compared with that of the other cultivars, about 50%. From these results, Korean plums turned out to be phytochemical rich fruit as well as to show high antioxidant activities.

Theaflavin ameliorates behavioral deficits, biochemical indices and monoamine transporters expression against subacute 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of Parkinson's disease

Evidence from clinical and experimental studies indicates that degeneration of nigrostriatal dopaminergic neurons is a pathological hallmark of Parkinson's disease (PD). The present study was designed to investigate the neuroprotective potential of theaflavin (TF) on oxidative stress, monoamine transporters and behavioral abnormalities in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurodegeneration. TF, a black tea polyphenol, has been known to possess neuroprotective effects against ischemia, Alzheimer's disease and other neurodegenerative disorders, but the mechanisms underlying its beneficial effects on MPTP-induced dopaminergic neurodegeneration are poorly defined. Administration of MPTP (30 mg/kg bw for four consecutive days) led to increased oxidative stress and reduced behavior patterns (open field, rotarod and hang test), nigrostriatal dopamine transporter (DAT) (immunohistochemistry and Western blot) and vesicular monoamine transporter 2 (VMAT2) (Western blot) expressions. Pre-treatment with TF reduces oxidative stress, improves motor behavior and expression of DAT and VMAT2 in striatum and substantia nigra. These results indicate that TF might be beneficial in mitigating MPTP-induced damage of dopaminergic neurons, possibly via its neuroprotective and its antioxidant potential.