Phenylpropanoids from Ballota nigra L. inhibit in vitro LDL peroxidation

Forsythoside B attenuates neuro-inflammation and neuronal apoptosis by inhibition of NF-κB and p38-MAPK signaling pathways through activating Nrf2 post spinal cord injury

BACKGROUND

Spinal cord injury (SCI) is a ruinous neurological pathology that results in locomotor and sensory impairment. Neuro-inflammation and secondary neuronal apoptosis contribute to SCI, with anti-inflammatory therapies the focus of many SCI studies. Forsythoside B (FTS•B), a phenylethanoid glycoside extracted from the leaves of Lamiophlomis rotata Kudo, has been shown previously to have anti-inflammatory properties. Nevertheless, the therapeutic effect of FTS•B on neuro-inflammation after SCI is unknown.

METHODS

Neuro-inflammation was assessed by western blotting (WB), immunofluorescence (IF) staining, and enzyme-linked immunosorbent assay (ELISA) both in vitro and in vivo. Secondary neuronal apoptosis was simulated in a microglia-neuron co-culture model with the degree of apoptosis measured by WB, IF, and TUNEL staining. In vivo, FTS•B (10 mg/kg, 40 mg/kg) were intraperitoneally injected into SCI mice. Morphological changes following SCI were evaluated by Nissl, Hematoxylin-eosin, and Luxol Fast Blue staining. Basso Mouse Scale scores were used to evaluate locomotor function recovery.

RESULTS

FTS•B markedly decreased the levels of iNOS, COX-2 and signature mediators of inflammation. Phosphorylated p38 and nuclear factor-kappa B (NF-κB) were markedly decreased by FTS•B. Additionally, FTS•B-induced inhibition of NF-κB and p38-MAPK signaling pathways was reversed by Nrf2 downregulation. Administration of FTS•B also significantly reduced apoptosis-related protein levels indicating that FTS•B ameliorated secondary neuronal apoptosis. FTS•B administration inhibited glial scar formation, decreased neuronal death, tissue deficiency, alleviated demyelination, and promoted locomotor recovery.

CONCLUSION

FTS•B effectively attenuates neuro-inflammation and secondary neuronal apoptosis by inhibition of NF-κB and p38-MAPK signaling pathways through activating Nrf2 after SCI. This study demonstrates FTS•B to be a potential therapeutic for SCI.

Antioxidant and Pro-Oxidant Capacities as Mechanisms of Photoprotection of Olive Polyphenols on UVA-Damaged Human Keratinocytes

A wide variety of polyphenols are reported to have considerable antioxidant and skin photoprotective effects, although the mechanisms of action are not fully known. Environmentally friendly and inexpensive sources of natural bioactive compounds, such as olive mill wastewater (OMWW), the by-product of olive-oil processing, can be considered an economic source of bioactive polyphenols, with a range of biological activities, useful as chemotherapeutic or cosmeceutical agents. Green strategies, such as the process based on membrane technologies, allow to recover active polyphenols from this complex matrix. This study aims to evaluate the antioxidant, pro-oxidant, and photoprotective effects, including the underlying action mechanism(s), of the ultra-filtered (UF) OMWW fractions, in order to substantiate their use as natural cosmeceutical ingredient. Six chemically characterized UF-OMWW fractions, from Italian and Greek olive cultivar processing, were investigated for their antioxidant activities, measured by Trolox Equivalent Antioxidant Capacity (TEAC), LDL oxidation inhibition, and ROS-quenching ability in UVA-irradiated HEKa (Human Epidermal Keratinocytes adult) cultures. The photoprotective properties of UF-OMWW were assayed as a pro-oxidant-mediated pro-apoptotic effect on the UVA-damaged HEKa cells, which can be potentially involved in the carcinogenesis process. All the UF-OMWW fractions exerted an effective antioxidant activity in vitro and in cells when administered together with UV-radiation on HEKa. A pro-oxidative and pro-apoptotic effect on the UVA-damaged HEKa cells were observed, suggesting some protective actions of polyphenol fraction on keratinocyte cell cultures.

GC and GC-–MS Analysis of Volatile Compounds From Ballota nigra subsp. uncinata Collected in Aeolian Islands, Sicily (Southern Italy)

In the present study, the chemical composition of the essential oils from aerial parts of Ballota nigra subsp. uncinata (Bég.) Patzak collected in Sicily was evaluated by gas chromatography (GC) and GC-mass spectrometry. The main components of the oil were ( E)-phytol (20.0%), α-pinene (9.0%), hexahydrofarnesyl acetone (5.7%), and α-selinene (5.1%). Cluster analysis of the essential oil compositions of all the taxa belonging to B. nigra s.l. group was performed.

Anxiolytic and Antidepressant Effects of the Hydroethanolic Extract from the Leaves of Aloysia polystachya (Griseb.) Moldenke: A Study on Zebrafish (Danio rerio)

Medicinal plants such as Aloysia polystachya are often used in the treatment of psychiatric diseases, including anxiety- and depression-related humor disturbances. In folk medicine, A. polystachya is used to treat digestive and respiratory tract disturbances, as a sedative and antidepressant agent, and as a tonic for the nerves. This study aimed to evaluate the antidepressant and anxiolytic effect from the hydroethanolic extract from the leaves of Aloysia polystachya (HELAp) in zebrafish. The extract was analyzed through ultra-performance liquid chromatography-mass spectroscopy (UPLC-MS) and the main compound detected was acteoside. HELAp was administered orally (10 mg/kg) and through immersion (mg/L). The anxiolytic activity was evaluated through the scototaxis (light–dark) test using caffeine as an anxiogenic agent and buspirone as a positive control. The parameters assessed were: period spent in the white compartment (s), latency (s), alternations (n), erratic swims (n), period of freezing (s), thigmotaxis (s), and risk evaluation (n). The antidepressant effect was evaluated through the novel tank diving test using 1% ethanol, unpredictable chronic stress, and social isolation as depressors; fluoxetine was used as a positive control. The parameters assessed were: period spent at the top of the tank, latency, quadrants crossed, erratic swim, period of freezing, and distance of swam. The main chemical compound of HELAp was acteoside. The administration of the extract on zebrafish managed to revert the anxiogenic effect of caffeine without impairing their locomotion. Additionally, the treatment exerted antidepressant activity similarly to fluoxetine. Overall, the results suggest a significant anxiolytic and antidepressant activity to the extract, which is probably due to the presence of the major compound, acteoside.

A review on traditional uses, phytochemistry and pharmacological activities of the genus Ballota

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Ballota L. (Lamiaceae) comprises 33 to 35 species distributed mainly in temperate and subtropical regions of the world. Some species have been used in folk medicine as antiemetic, antispasmodic, sedative agents, vermifuge, antihemorrhoid and also in treatment of cough, etc. AIM OF THIS REVIEW: This review article aims to provide organized information on the available traditional uses, phytochemical and pharmacological studies of the genus Ballota, and to obtain new insights for further researches.

MATERIALS AND METHODS

Electronic databases, including Web of Science, Science Direct, Google Scholar, Scopus, PubMed, and Springer Link were used as information sources. General web searches were carried out using Google and Yahoo search engines by applying related search terms. Additional information was derived from books and journals in English, Latin and Persian, and also Ph.D. theses and M.Sc. dissertations.

RESULTS

Terpenoids (particularly furanolabdane diterpenoids) and flavonoids were the main phytochemical classes identified in the extracts of Ballota species. Furanolabdane diterpenoids, e.g. ballonigrin, dehydrohispanolone, and hispanolone were reported in many species of Ballota. β-Caryophyllene, caryophyllene oxide, and germacrene D were found as the most common major compounds isolated from the essential oils of the genus Ballota. Sixty-four pharmacological studies conducted on cell lines, microorganisms, and animals were included in this review. Some species of Ballota exhibited various pharmacological activities, including promising antidepressant, anxiolytic, sedative-hypnotic, and antitussive activities in animal models. The pharmacological activities can be attributed to bioactive phytochemicals.

CONCLUSION

The genus Ballota is a valuable source of bioactive compounds with therapeutic potential in different diseases. Some pharmacological studies showed incomplete methodologies and ambiguous findings. Thus, the research designs of pharmacological studies based on traditional uses of Ballota species are strongly needed in cell lines and animal models. More in vitro and in vivo animal studies are required to confirm the safety, clarification of the effective doses, bioactive compounds, and the mechanisms of actions before future clinical studies.

Reactivity of Metal-Free and Metal-Associated Amyloid-β with Glycosylated Polyphenols and Their Esterified Derivatives

Both amyloid-β (Aβ) and transition metal ions are shown to be involved in the pathogenesis of Alzheimer's disease (AD), though the importance of their interactions remains unclear. Multifunctional molecules, which can target metal-free and metal-bound Aβ and modulate their reactivity (e.g., Aβ aggregation), have been developed as chemical tools to investigate their function in AD pathology; however, these compounds generally lack specificity or have undesirable chemical and biological properties, reducing their functionality. We have evaluated whether multiple polyphenolic glycosides and their esterified derivatives can serve as specific, multifunctional probes to better understand AD. The ability of these compounds to interact with metal ions and metal-free/-associated Aβ, and further control both metal-free and metal-induced Aβ aggregation was investigated through gel electrophoresis with Western blotting, transmission electron microscopy, UV-Vis spectroscopy, fluorescence spectroscopy, and NMR spectroscopy. We also examined the cytotoxicity of the compounds and their ability to mitigate the toxicity induced by both metal-free and metal-bound Aβ. Of the polyphenols investigated, the natural product (Verbascoside) and its esterified derivative (VPP) regulate the aggregation and cytotoxicity of metal-free and/or metal-associated Aβ to different extents. Our studies indicate Verbascoside represents a promising structure for further multifunctional tool development against both metal-free Aβ and metal-Aβ.

Verbascoside--a review of its occurrence, (bio)synthesis and pharmacological significance

Phenylethanoid glycosides are naturally occurring water-soluble compounds with remarkable biological properties that are widely distributed in the plant kingdom. Verbascoside is a phenylethanoid glycoside that was first isolated from mullein but is also found in several other plant species. It has also been produced by in vitro plant culture systems, including genetically transformed roots (so-called 'hairy roots'). Verbascoside is hydrophilic in nature and possesses pharmacologically beneficial activities for human health, including antioxidant, anti-inflammatory and antineoplastic properties in addition to numerous wound-healing and neuroprotective properties. Recent advances with regard to the distribution, (bio)synthesis and bioproduction of verbascoside are summarised in this review. We also discuss its prominent pharmacological properties and outline future perspectives for its potential application.

A novel strategy to evaluate the quality of traditional Chinese medicine based on the correlation analysis of chemical fingerprint and biological effect

A novel strategy was developed to assess the quality of TCM (traditional Chinese medicine) based on the correlation analysis of the chemical fingerprint and biological effect. Using Rehmanniae glutinosa (RG) to treat the kidney yin deficiency as an example, chemical fingerprints of 27 RG samples were analyzed by liquid chromatography-mass spectrometry (LC-MS), and urinary metabolic profiling of RG treatment of kidney yin deficiency in rats was explored by using LC-MS. A correlation analysis between the chemical fingerprints and efficacy evaluation was developed to identify quality marker components to assess TCM quality. Thirty-four variables in chemical fingerprints were successfully defined to have a close relationship with the efficacy of RG. The validation test with a new RG sample indicated that these efficacy-related components could be used to evaluate the integral quality of RG accurately. Compared with conventional chemical fingerprint methodology, not only is the proposed approach a powerful tool to identify efficacy-related components for the quality evaluation of TCM, but the approach can also be used to predict the therapeutic efficacy of TCMs.

Verbascoside, isoverbascoside, and their derivatives recovered from olive mill wastewater as possible food antioxidants

Olive oil processing industries generate substantial quantities of phenolic-rich byproducts, which could be valuable natural sources of antioxidants. This work is focused on the recovery and structural characterization of antioxidant compounds from olive mill wastewater (OMWW), a polluting byproduct of the olive oil production process. Phenolics were extracted from the waste material using a membrane technology coupled to low-pressure gel filtration chromatography on a Sephadex LH-20. The LH-20 fraction was, in turn, characterized for its phenolic composition by HPLC-DAD-MS/MS analyses. Verbascoside, isoverbascoside, β-hydroxyverbascoside, β-hydroxyisoverbascoside, and various oxidized phenolics were identified. Uptake of verbascoside, purified from the LH-20 fraction, by HT-29 cells, an established model system for studying drug transport properties, was also assayed. Finally, the antioxidant activities of the LH-20 fraction and verbascoside were characterized by two different techniques. Individual verbascoside was more active as a scavenger of reactive oxygen species and as a chemopreventive agent protecting low-density lipoproteins from oxidative damage than the LH-20 fraction.

Radical quenching activity, ferric-reducing antioxidant power, and ferrous ion-chelating capacity of 16 Ballota species and their total phenol and flavonoid contents

The ethyl acetate, methanol, and water extracts of 16 Ballota species (Family Lamiaceae)-Ballota acetabulosa, Ballota antalyanse, Ballota cristata, Ballota glandulosissima, Ballota inaequidens, Ballota larendana, Ballota latibracteolata, Ballota macrodonta, Ballota nigra ssp. anatolica, B. nigra ssp. foetida, B. nigra ssp. nigra, B. nigra ssp. uncinata, Ballota pseudodictamnus ssp. lycia, Ballota rotundifolia, Ballota saxatilis ssp. brachyodonta, and B. saxatilis subsp. saxatilis-were screened for their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical quenching, ferric-reducing antioxidant power, and ferrous ion-chelating capacity at 1mg/mL. Hispanolone, a major diterpene found in the Ballota genus, was also tested in the same manner. Total phenol and flavonoid contents of the extracts were determined by Folin-Ciocalteau and AlCl(3) reagents, respectively. The extracts showed insignificant quenching activity against DPPH radical, but they had moderate antioxidant activity (0.597 ± 0.03 to 1.342 ± 0.01) in the ferric-reducing test compared to chlorogenic acid (the reference compound) (3.618 ± 0.01). All of the extracts (ranging from 65.1 ± 0.64% to 96.3 ± 0.09%) and hispanolone (97.31 ± 0.30%) exerted a remarkable ferrous ion-chelating effect. The highest total phenol (gallic acid equivalent) and flavonoid (quercetin equivalent) contents were found in the ethyl acetate extract of B. glandulosissima (393.7 ± 3.03 and 140.6 ± 1.97 mg/g of extract, respectively). Therefore, Ballota species could be a good source of natural preservatives in foodstuffs.

Effects of extracts from Italian medicinal plants on planktonic growth, biofilm formation and adherence of methicillin-resistant Staphylococcus aureus

AIM OF STUDY

One-third of botanical remedies from southern Italy are used to treat skin and soft tissue infection (SSTI). Staphylococcus aureus, a common cause of SSTI, has generated increasing concern due to drug resistance. Many plants possess antimicrobial agents and provide effective remedies for SSTI. Our aim was to investigate plants from different ethnobotanical usage groups for inhibition of growth and biofilms in methicillin-resistant Staphylococcus aureus (MRSA).

MATERIALS AND METHODS

Three groups were assessed: plant remedies for SSTI, plant remedies not involving the skin, and plants with no ethnomedical application. We screened 168 extracts, representing 104 botanical species, for activity against MRSA (ATCC 33593). We employed broth dilution methods to determine the MIC after 18 h growth using an optical density (OD 600 nm) reading. Anti-biofilm effects were assessed by growing biofilms for 40 h, then fixing and staining with crystal violet. After washing, 10% Tween 80 was added and OD 570 nm readings were taken.

RESULTS

Extracts from 10 plants exhibited an IC50<or=32 microg/ml for biofilm inhibition: Lonicera alpigena, Castanea sativa, Juglans regia, Ballota nigra, Rosmarinus officinalis, Leopoldia comosa, Malva sylvestris, Cyclamen hederifolium, Rosa canina, and Rubus ulmifolius. Limited bacteriostatic activity was evident.

CONCLUSION

This study has demonstrated that the anti-biofilm activity of medicinal plants used for SSTI is significantly greater than plants without any ethnomedical applications.

A phenylpropanoid glycoside with antioxidant activity from Picria tel-ferae

A phytochemical study on Picria tel-ferae resulted in the isolation of a phenylpropanoid glycoside (1), which was reported for the first time from this plant. The structure of compound 1 was identified as 1-O-3,4-(dihydroxyphenyl)- ethyl-beta-D- apiofuranosyl- (1-->4)-alpha-L-rharmnopyranosyl- (1-->3)-4-O-caffeoyl- beta-D-glucopyranoside on the basis of spectroscopic analyses. In addition, it was found that 1 exhibited a remarkable inhibitory effect on lipid peroxidation initiated by either a free radical [AAPH; 2,2'-azobis-(2-amidinopropane)dihydrochloride] or generated hydroxyl radical (Fe2+/ascorbate). These findings, together with those of previous studies, suggest that P. tel-ferae possesses abundant phenylpropanoid glycosides, and the plant might be used beneficially in the treatment of oxidative stress-related human diseases.

Marrubium vulgare extract inhibits human-LDL oxidation and enhances HDL-mediated cholesterol efflux in THP-1 macrophage

The objective of the present study was to elucidate the beneficial properties of aqueous extracts of Marrubium vulgare (AEM) towards cardiovascular disease by protecting human-LDL against lipid peroxidation and promoting HDL-mediated cholesterol efflux. Human-LDL were oxidised by incubation with CuSO(4) in the presence of increased concentrations of AEM (0-100 microg/ml). LDL lipid peroxidation was evaluated by conjugated diene formation, vitamin E disappearance as well as LDL-electrophoretic mobility. HDL-mediated cholesterol efflux assay was carried out in human THP-1 macrophages. Incubation of LDL with AEM significantly prolonged the lag phase (P=0.014), lowered the progression rate of lipid peroxidation (P=0.004), reduced the disappearance of vitamin E and the electrophoretic mobility in a dose-dependent manner. Also, incubation of HDL with AEM significantly increased HDL-mediated cholesterol efflux from THP-1 macrophages implicating an independent ATP binding cassette A1 (ABCA1) pathways. Our findings suggest that M. vulgare provides a source of natural antioxidants, which inhibit LDL oxidation and enhance reverse cholesterol transport and thus can prevent cardiovascular diseases development. These antioxidant properties increase the anti-atherogenic potential of HDL.

Protective Effect of Lignophenol Derivative from Beech (Fagus crenata Blume) on Copper- and Zinc-Mediated Cell Death in PC12 Cells

Lignophenol, prepared using a phase-separation system, is a derivative of lignin, which is one of the components in the plant cell wall, and possesses high phenolic function, high stability and antioxidant properties. However, little is known about the beneficial effect of lignophenol. In this study, we investigated the protective effect of lignophenol from the beech tree (Fagus crenata Blume) on copper- and zinc-mediated apoptosis in PC12 cells by using DNA fragmentation and TUNEL assays. In DNA fragmentation assays, the DNA ladder patterns in the PC12 cells treated with 200 microM Cu and 200 microM Zn were enhanced, whereas the DNA ladder pattern was hardly observed in these cells treated with 20 mM lignophenol. In the TUNEL assay, TUNEL signals increased significantly in the untreated PC12 cells exposed to 200 microM Cu compared with the control. In contrast, the degree of apoptosis in the 20 mM lignophenol-treated cells was significantly lower than in the untreated cells, indicating that lignophenol inhibited Cu-induced apoptotic cell death in PC 12 cells. In the 200 microM Zn-exposed group, the degree of apoptosis in the 20 mM lignophenol-treated cells was also low compared with the untreated cells. In conclusion, these results suggest that lignophenol plays a role in protecting against Cu- and Zn-mediated PC12 apoptotic cell death.

Acteoside and martynoside exhibit estrogenic/antiestrogenic properties

Acteoside and martynoside are plant phenylpropanoid glycosides exhibiting anticancer, cytotoxic and antimetastatic activities. We investigated their potential to activate estrogen receptor isoforms ERalpha and ERbeta in HeLa cells transfected with an estrogen response element (ERE)-driven luciferase (Luc) reporter gene and an ERalpha or ERbeta expression vector. Their estrogenic/antiestrogenic effects were also assessed in breast cancer cells (MCF7), endometrial cancer cells (Ishikawa) and osteoblasts (KS483), by measuring IGFBP3 levels, cell viability and number of mineralized nodules, respectively, seeking for a natural selective estrogen receptor modulator (SERM). Acteoside and martynoside antagonized both ERalpha and ERbeta (p<0.001), whereas they reversed the effect of E(2) mainly via ERalpha (p<0.001). Martynoside was a potent antiestrogen in MCF-7 cells, increasing, like ICI182780, IGFBP3 levels via the ER-pathway. In osteoblasts, martynoside induced nodule mineralization, which was abolished by ICI182780, implicating an ER-mediated mechanism. Furthermore, its antiproliferative effect on endometrial cells suggests that martynoside may be an important natural SERM. Acteoside was an antiestrogen in breast cancer cells and osteoblasts, without any effect on endometrial cells. Our study suggests that the nature is rich in selective ERalpha and ERbeta ligands, the discovery of which may lead to the development of novel neutraceutical agents.

Antioxidant properties of Ballota species growing in Turkey

In the present study, the antioxidant properties of ethanol extracts of 16 Ballota species belonging to the Lamiaceae family and growing in Turkey on superoxide anion formation and lipid peroxidation were investigated. All extracts inhibited superoxide anion formation but to different extents. The extracts of Ballota antalyense, Ballota macrodonta, Ballota glandulosissima, Ballota larendana, Ballota pseudodictamnus, Ballota nigra subsp. anatolica, Ballota saxatilis subsp. saxatilis, Ballota rotundifolia, and Ballota saxatilis subsp. brachyodonta exhibited remarkable anti-superoxide anion formation with IC(50) values from 0.50 to 0.87 mg/ml. The extracts of Ballota antalyense, Ballota macrodonta and Ballota glandulosissima have the lowest IC(50) values (0.50, 0.51 and 0.51 mg/ml, respectively) which were rather close to the well-known superoxide anion scavenger alpha-tocopherol (IC(50): 0.22 mg/ml). The extracts of Ballota inaequidens, Ballota glandulosissima, Ballota saxatilis subsp. saxatilis, Ballota macrodonta and Ballota antalyense inhibited lipid peroxidation with IC(50) values from 12 to 20 mg/ml. The extracts of Ballota inaequidens (IC(50): 12 mg/ml) and Ballota glandulosissima (IC(50): 15 mg/ml) exhibited the strongest inhibitory effects on lipid peroxidation compared with alpha-tocopherol (IC(50): 3 mg/ml). The results show that Ballota glandulosissima is the best antioxidant source among these 16 Ballota species.

Screening of antioxidant activity of three Indian medicinal plants, traditionally used for the management of neurodegenerative diseases

A number of Indian medicinal plants have been used for thousands of years in the traditional system of medicine (Ayurveda). Amongst these are plants used for the management of neurodegenerative diseases such as Parkinson's, Alzheimer's, loss of memory, degeneration of nerves and other neuronal disorders by the Ayurvedic practitioners. Though the etiology of neurodegenerative diseases remains enigmatic, there is evidence, which indicates that defective energy metabolism, excitotoxicity and oxidative damage may be crucial factors (Ann. Neurol. 38 (3) (1995) 357). The part of the Ayurvedic system that provides an approach to prevention and treatment of degenerative diseases is known as Rasayana, and plants used for this purpose are classed as rejuvenators. This group of plants generally possesses strong antioxidant activity (Pharmacol. Biochem. Behav. 43 (1992) 1175), but only a few have been investigated in detail. In the present study, three such rasayana plants were tested for the first time for their toxicity and free radical scavenging activity both in vitro and ex vivo. All the three plant infusions (up to 1 mg/ml) showed no toxic effects on the viability of PC12 cell line as judged by MTT-test. Both ethanolic extracts and water infusions of the plants were tested for their antioxidant activity in the 2,2'-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS*(+)) radical cation decolorization assay; inhibition of lipid peroxidation by plant infusions was carried out using spontaneous lipid peroxidation of rat brain homogenate, and IC50 values were determined. The results from the ABTS assay showed that the ethanolic extract of Sida cordifolia was found to be most potent (IC50 16.07 microg/ml), followed by Evolvulus alsinoides (IC50 33.39 microg/ml) and Cynodon dactylon (IC50 78.62 microg/ml). The relative antioxidant capacity for the water infusions was observed in the following order: E. alsinoides (IC50 172.25 microg/ml)>C. dactylon (IC50 273.64 microg/ml)>S. cordifolia (IC50 342.82 microg/ml). The results of water infusions of the plants on lipid peroxidation were as follows: E. alsinoides (IC50 89.23 microg/ml)>S. cordifolia) (IC50 126.78 microg/ml)>C. dactylon (IC50 608.31 microg/ml).

Synergistic antioxidative properties of phenolics from natural origin toward low-density lipoproteins depend on the oxidation system

Using an approach in line with that of a previous report, we assessed the antioxidant activity of several natural, polyphenol- or tocotrienol-rich mixtures: extracts from Elaesis Guineensis oil (A) and Vitis vinifera (B), a Coffea robusta powder (C), and extracts from Olea europea mill wastewaters (D), Solanum melongena (E), and Lycopersicon esculentum (F). The copper- and 2-2'-azobis(2-amidinopropane) hydrochloride (AAPH)-oxidation systems were used in the presence of low-density lipoprotein. For comparison, antioxidant activities of chlorogenic acid and catechin, as archetypes of molecules highly efficient with the copper- and the AAPH-oxidation system, respectively, were assessed. The aim was to establish the occurrence of synergistic antioxidant actions among some of these natural mixtures. On a molar basis, the highest specific antioxidant activities (SAA) were found for B, chlorogenic acid, and C in the copper system, and for A, catechin, and B in the AAPH system. On a mass basis, the highest SAA were found, respectively, for chlorogenic acid, B, and catechin, and for catechin, chlorogenic acid, and B. These results show that large discrepancies take place in the evaluations between the two systems. B and C exhibited a synergistic antioxidant efficiency, in the presence or absence of A, but only with the copper system. This was also true for the two types of A+B+C mixture that were tested. It is thought that this association might provide an ideal combination, incorporating both the radical scavenger and the transition-metal ion chelation properties of B and C.

Studies on the antioxidant activity of Lippia citriodora infusion: scavenging effect on superoxide radical, hydroxyl radical and hypochlorous acid

Lippia citriodora is an herbal species which contains several flavonoids and phenolic acids. In view of the pharmacological interest in natural phenolic compounds as antioxidants, this study examined the superoxide radical, hydroxyl radical and hypochlorous acid scavenging activities of L. citriodora infusion. Superoxide radical was generated either in an enzymatic or in a chemical system, and scavenging ability was assessed by the inhibition of nitroblue tetrazolium reduction. Hydroxyl radical was generated by the reaction of an iron-EDTA complex with H2O2 in the presence of ascorbic acid, and was assayed by evaluating deoxyribose degradation. Hypochlorous acid scavenging activity was tested by measuring the inhibition of 5-thio-2-nitrobenzoic acid oxidation. The results demonstrate that this infusion has a potent superoxide radical scavenging activity and a moderate scavenging activity of hydroxyl radical and hypochlorous acid. The chemical composition of the lyophilized infusion was also determined in an attempt to establish its relationship with the antioxidant activity found in the present study.

Antimetastatic activity of acteoside, a phenylethanoid glycoside

We examined the antimetastatic effect of acteoside, a phenylethanoid glycoside widely distributed in the plant kingdom, on lung metastasis using a mouse model injected with B16 melanoma cells intravenously. Male C57BL/6 mice were injected intravenously with 2 x 10(5) of B16 melanoma cells, while acteoside at a dose of 50 mg/kg was administered intraperitoneally every other day from 13 d before B16 melanoma cell injection until all mice had succumbed to the metastatic tumor burden in the lung. Administration of acteoside prolonged survival time significantly and the average survival time was 63.3 +/- 3.4d compared with 52.1 +/- 2.5d in control mice. This result suggests that acteoside showed suppressive effect on lung metastasis of B16 melanoma cells.

CueO is a multi-copper oxidase that confers copper tolerance in Escherichia coli

The putative multi-copper oxidase CueO had previously been implicated in intrinsic copper resistance in Escherichia coli. In this report we showed that the presence of CueO in the periplasm protected alkaline phosphatase from copper-induced damage. CueO contained four copper atoms per molecule and displayed spectroscopic properties typical of blue copper oxidases. CueO catalyzed the oxidation of p-phenylenediamine (pPD), 2,6-dimethoxyphenol (DMP) and exhibited ferroxidase activity in vitro.

Two major flavonoids from Ballota nigra

Two lactoylate flavonoids, luteolin-7-lactate and luteolin-7-glucosyl-lactate were isolated from Ballota nigra. They should be used for the chemical standardization of this drug of medicinal interest.