Dietary calcium impairs tomato lycopene bioavailability in healthy humans.

Lycopene (LYC) bioavailability is relatively low and highly variable, because of the influence of several factors. Recent in vitro data have suggested that dietary Ca can impair LYC micellarisation, but there is no evidence whether this can lead to decreased LYC absorption efficiency in humans. Our objective was to assess whether a nutritional dose of Ca impairs dietary LYC bioavailability and to study the mechanism(s) involved. First, in a randomised, two-way cross-over study, ten healthy adults consumed either a test meal that provided 19-mg (all-E)-LYC from tomato paste or the same meal plus 500-mg calcium carbonate as a supplement. Plasma LYC concentration was measured at regular time intervals over 7 h postprandially. In a second approach, an in vitro digestion model was used to assess the effect of increasing Ca doses on LYC micellarisation and on the size and zeta potential of the mixed micelles produced during digestion of a complex food matrix. LYC bioavailability was diminished by 83 % following the addition of Ca in the test meal. In vitro, Ca affected neither LYC micellarisation nor mixed micelle size but it decreased the absolute value of their charge by 39 %. In conclusion, a nutritional dose of Ca can impair dietary LYC bioavailability in healthy humans. This inhibition could be due to the fact that Ca diminishes the electrical charge of micelles. These results call for a thorough assessment of the effects of Ca, or other divalent minerals, on the bioavailability of other carotenoids and lipophilic micronutrients.

A meta-analysis to assess the effect of the composition of dietary fat on α-tocopherol blood and tissue concentration in pigs.

A meta-analysis based on the results from 13 selected publications was performed to assess the effect of dietary fat supplementation (quantity and fatty acid composition) on α-tocopherol (TOL) concentration in 4 pig tissues (blood, liver, muscle, and adipose tissue). Dietary fat supplementation was defined by the quantity of fat added to the basal diet and its fatty acid profile. After standardization of tissue TOL concentration (as the dependent variable), statistical analyses were performed using multiple nonlinear regression, data partitioning, and partial least squares regression with 7 predictor variables including added vitamin E (VE), added fat, PUFA (% fat), MUFA (% fat), SFA (% fat), omega-3 fatty acids (-3; % fat), and omega-6 fatty acids (-6; % fat). The statistical analyses first showed that the VE level in the diet was the main factor that modulates tissue TOL concentration. The dose-response relationship followed a logarithmic curve, with a saturation of tissue TOL concentration in all the studied tissues. Moreover, the amount of dietary fat, at least up to 20%, was not linearly correlated with tissue TOL concentration, considering that the main fatty acid classes, MUFA and, to a lesser extent, SFA, were positively associated with tissue TOL concentrations. Finally, this study suggests that the inclusion of -3 fatty acids in the diet may decrease tissue and, more precisely, blood TOL concentration.

Profisetinidin type tannins responsible for antioxidant activity in Copaifera reticulata.

The in vitro antioxidant and free radical scavenging properties in bark extracts of South American tree Copaifera reticulata Ducke. (Caesalpinaceae) were studied using different bioassays. Lipid peroxidation was assessed by means of the production of thiobarbituric acid reactive substances (TBARS) in rat liver homogenate. All the extracts tested were effective in this method. The highest activity was observed in the aqueous extract, showing an IC50 of 30 micrograms/ml. DNA sugar damage induced by Fe (II) salts was also used to determine the capacity of the samples to suppress hydroxyl radical-mediated degradation of DNA. Although all the extracts tested were effective in reducing oxidation of DNA, the highest activity was observed in the methanol extract, showing an IC50 of 2 micrograms/ml. Bioassay-guided fractionation of a total methanol extract monitored by luminol-enhanced chemiluminescence, together with structural elucidation using 13C NMR and FABMS, led to the identification of profisetinidin type tannins in a semi-pure fraction. The fraction containing the active compounds also reduced the production of TBARS in rat liver homogenates (IC50 = 530 micrograms/ml) and DNA damage (IC50 = 1 microgram/ml), suggesting that profisetinidins could be responsible for the free radical scavenging and antioxidant activities observed in the extracts.

Anti-inflammatory activity of Pothomorphe peltata leaf methanol extract.

The methanol extract of Pothomorphe peltata leaves, orally administered at the dose of 20 mg/kg (equivalent to 2.50 g dry plant/kg) body weight, exhibited a significant anti-inflammatory activity, comparable with phenylbutazone (80 mg/kg, p.o.), against adjuvant-carrageenan-induced edema in rats.

Cytotoxic 4-nerolidylcatechol from Pothomorphe peltata inhibits topoisomerase I activity.

Bioactivity-guided fractionation of the leaf methanolic extract of P. peltata (Piperaceae), using the brine shrimp lethality test, led to the isolation of catechol derivative 4-nerolidylcatechol (4-NC). The methanolic extract was active against crown gall tumour in potato discs, showing a 22% crown gall tumour inhibition (SD = 4%), while 4-NC was cytotoxic against KB tumour cells growth (EC50 = 1.3 micrograms/ml). No interaction with DNA could be observed when tested using the methyl green-DNA (MG-DNA) bioassay. An inhibition in the activity of topoisomerase I using agarose gel electrophoresis was detected in the presence of the purified compound (IC50 = 20 micrograms/ml), suggesting that this could be a possible mechanism for the cytotoxicity observed in KB cells.

Antioxidant and free radical scavenging activities in extracts from medicinal trees used in the 'Caatinga' region in northeastern Brazil.

The in vitro antioxidant and free radical scavenging properties of bark extracts of Anadenanthera macrocarpa Brenan (Fabaceae), Astronium urundeuva Engl. (Anacardiaceae), Mimosa verrucosa Benth. (Fabaceae) and Sideroxylon obtusifolium T.D. Penn. (Sapotaceae), four trees used as anti-inflammatory agents in the Brazilian state of Bahia, were studied using different bioassays. The total reactive antioxidant potential (TRAP) of the aqueous and methanolic extracts was determined by monitoring the intensity of luminol-enhanced chemiluminescence (CL), using 2,2'-azo-bis(2-amidinopropane) as a peroxyl radical source. All the extracts studied were active in this method. The highest activity, measured as equivalents of Trolox concentration, was observed in the methanolic extract of A. macrocarpa (TRAP = 3028 +/- 95 microM). Lipid peroxidation was assessed by means of the production of thiobarbituric acid reactive substances (TBARS) and hydroperoxide-initiated CL in rat liver homogenates. As in the case of luminol-enhanced CL, all the extracts tested were effective in reducing the production of TBARS. The highest activity was observed in the aqueous extract of A. macrocarpa (IC50 = 54 microg/ml). Extracts of A. macrocarpa and S. obtusifolium also reduced hydroperoxide-initiated CL, the methanolic extract of the former being the most active, showing an IC50 = 2.0 microg/ml. DNA-sugar damage induced by Fe(II) salts was also used to determine the capacity of the extracts to suppress hydroxyl radical-mediated degradation of DNA. All extracts tested were highly effective in reducing oxidation of DNA. The highest activity was observed in the methanolic extract of A. urundeuva, showing an IC50 = 37 microg/ml. The results obtained suggest that the antioxidant activity described could play an important role in the anti-inflammatory activity claimed for the plants under study.

Antioxidant and free radical scavenging effects in extracts of the medicinal herb Achyrocline satureioides (Lam.) DC. ("marcela")

Achyrocline satureioides (Lam.) DC. (Compositae) is a medicinal herb used in Argentina, Uruguay, Brazil and Paraguay for its choleretic, antispasmodic and hepatoprotective properties. The presence of the flavonoid quercetin and its derivatives, and of different phenolic acids such as caffeic, chlorogenic and isochlorogenic acids in the aerial parts of this plant has led us to study the antioxidant activity of its extracts using different bioassays. The inhibition of luminol-enhanced chemiluminescence by the aqueous and methanolic extracts was used to show that their total reactive antioxidant potential index (TRAP; in µM Trolox equivalents) was 91.0 ñ 15.4 and 128.1 ñ 20.1 µM, respectively, while the total antioxidant reactivity index (TAR) was calculated to be 1537 ñ 148 and 1910 ñ 171 µM. Only the methanolic extract was capable of reducing iron (II)-dependent DNA damage. Lipid peroxidation was assessed by two different methods. The aqueous extract reduced hydroperoxide-initiated chemiluminescence in rat liver homogenates at all concentrations in a dose-dependent manner, with a calculated IC50 = 225 µg/ml, while the methanolic extract was only effective at higher concentrations (100 and 1000 µg/ml). Both aqueous and methanolic extracts were capable of reducing the production of thiobarbituric acid reactive substances (TBARS) in rat liver homogenates, with an IC50 >1000 µg/ml. The results obtained suggest that the extracts of A. satureioides possess significant free radical scavenging and antioxidant activity in vitro, a fact that should encourage future in vivo studies

Antioxidant and free radical scavenging effects in extracts of the medicinal herb Achyrocline satureioides (Lam.) DC. ("marcela").

Achyrocline satureioides (Lam.) DC. (Compositae) is a medicinal herb used in Argentina, Uruguay, Brazil and Paraguay for its choleretic, antispasmodic and hepatoprotective properties. The presence of the flavonoid quercetin and its derivatives, and of different phenolic acids such as caffeic, chlorogenic and isochlorogenic acids in the aerial parts of this plant has led us to study the antioxidant activity of its extracts using different bioassays. The inhibition of luminol-enhanced chemiluminescence by the aqueous and methanolic extracts was used to show that their total reactive antioxidant potential index (TRAP; in microM Trolox equivalents) was 91.0 +/- 15.4 and 128.1 +/- 20.1 microM, respectively, while the total antioxidant reactivity index (TAR) was calculated to be 1537 +/- 148 and 1910 +/- 171 microM. Only the methanolic extract was capable of reducing iron (II)-dependent DNA damage. Lipid peroxidation was assessed by two different methods. The aqueous extract reduced hydroperoxide-initiated chemiluminescence in rat liver homogenates at all concentrations in a dose-dependent manner, with a calculated IC50 = 225 micrograms/ml, while the methanolic extract was only effective at higher concentrations (100 and 1000 micrograms/ml). Both aqueous and methanolic extracts were capable of reducing the production of thiobarbituric acid reactive substances (TBARS) in rat liver homogenates, with an IC50 > 1000 micrograms/ml. The results obtained suggest that the extracts of A. satureioides possess significant free radical scavenging and antioxidant activity in vitro, a fact that should encourage future in vivo studies.

Effects of Sangre de Drago from Croton lechleri Muell.-Arg. on the production of active oxygen radicals.

The total reactive antioxidant potential (TRAP) of 'Sangre de Drago' from Croton lechleri (Euphorbiaceae) was determined by monitoring the intensity of luminol enhanced chemiluminescence enhanced by peroxyl radicals derived from thermolysis of 2,2'-azo-bis(2-amidinopropane). The TRAP index was calculated as 935.4 +/- 141 microM, measured as equivalents of Trolox concentration. On the other hand, the additive incorporation of lower concentrations yielded an instantaneous increase in chemiluminescence, suggesting a prooxidant activity at these levels. DNA sugar damage induced by Fe(II) salts was also used to determine the capacity of the latex to suppress hydroxyl radical-mediated degradation of DNA. As in the case of luminol enhanced chemiluminescence, Sangre de Drago was highly effective in reducing oxidation of DNA at higher concentrations, but showed an increase in the production of TBARS at lower doses, as compared to the control. Finally, antioxidant activity was tested using hydroperoxide-initiated chemiluminescence in rat liver homogenates, and the latex showed an increase in light emission, suggesting the presence of prooxidant compounds.

Biological studies of Bolax gummifera, a plant of the Falkland Islands used as a treatment of wounds.

Aqueous and dichloromethane extracts of Bolax gummifera (Lam.) Sprengel (Apiaceae), a plant of the Falkland Islands used as a treatment of wounds, were studied in order to support the ethnopharmacological information related to the medicinal use of this plant. The antimicrobial, antioxidant and red blood cells membrane stabilizing activities were analyzed. The antimicrobial bioassay was carried out using the test turbidity method (OD 620 nm), the aqueous extract showing an 82% inhibition of Staphylococcus aureus but no activity against Pseudomonas aeruginosa. The dichloromethane extract inhibited both microorganisms: S. aureus in 94% and P. aeruginosa in 32%. No antioxidant activity could be observed using hydroperoxide-initiated chemiluminescence in rat liver homogenates. Investigations into the membrane stabilizing activity of the extracts were carried out using human red blood cells subjected to hypotonic- and heat-induced lyses. The aqueous extract showed an important stabilizing activity of the red blood cell membrane.

Inhibition of lipid peroxidation and iron (II)-dependent DNA damage by extracts of Pothomorphe peltata (L). Miq.

Leaves of Pothomorphe peltata (L.) Miq. (Piperaceae) are used locally as anti-inflammatory, antipyretic, hepatoprotective and diuretic infusions and to treat external ulcers and local infections in several parts of the Peruvian, Bolivian and Brazilian Amazon region. The antioxidant activity of different extracts of P. peltata was studied using the hydroperoxide-initiated chemiluminescence assay in liver homogenates, and the methanolic extract was found to have the highest antioxidant activity, with an IC50 = 4 micrograms/ml. Aqueous and dichloromethane extracts did not show antioxidant activity. The extracts were further evaluated using the thiobarbituric acid-reactive substances (TBARS) assay. Finally, an assay of DNA sugar damage induced by Fe (II) salt was used to determine the capacity of the extracts to suppress the oxidative degradation of DNA. All the extracts showed antioxidant activity in the latter two bioassays. The methanolic extract showed the highest activity in reducing oxidative damage to DNA, with an IC50 = 5 micrograms/ml. Since this extract was highly effective in reducing chemiluminescence and DNA damage, and because the latter activity could be due to the presence of compounds that bind to DNA, DNA-binding activity was studied using the DNA-methyl green (DNA-MG) bioassay. A 30% decrease in the initial absorbance of DNA-MG complex was observed in the methanolic extract at 1000 micrograms/ml, suggesting the presence of compounds that bind to genetic material. No DNA-binding activity was observed in the aqueous or dichloromethane extracts.

Inhibition of lipid peroxidation and iron (II)-dependent DNA damage by extracts of Pothomorphe peltata (L.) Miq

Leaves of Pothomorphe peltata (L.) Miq. (Piperaceae) are used locally as anti-inflammatory, antipyretic, hepatoprotective and diuret infusions and to treat external ulcers and local infections in several parts of the Peruvian, Bolivian and Brazilian Amazon region. The antioxidant activity of different extracts of P. peltata was studied using the hydroperoxide-initiated chemiluminescence assay in liver homogenates, and the methanolic extract was found to have the highest antioxidant activity, with an IC50 = 4 mug/ml. Aqueous and dichloromethane extracts did not show antioxidant activity. The extracts were further evaluated using the thiobarbituric acid-reactive substances (TBARS) assay. Finally, an assay of DNA sugar damarge induced by Fe (II) salt was used to determine the capacity of the extracts to suppress the oxidative degradation of DNA. All the extracts showed antioxidant activity in the latter two bioassays. The methanolic extract showed the highest activity in reducing oxidative damage to DNA, with an IC5O = 5 mug/ml. Since this extract was highly effective in reducing chemiluminescence and DNA damage, and because the latter activity could be due to the presence of compounds that bind to DNA, DNA-binding activity was studied using the DNA-methyl green (DNA-MG) bioassay. A 30 per cent decrease in the initial absorbance of DNA-MG complex was observed in the methanolic extract at 1000 mug/ml, suggesting the presence of compounds that bind to genetic material. No DNA-binding activity was observed in the aqueous or dichloromethane extracts.

In vitro antioxidant and cytotoxic activity of extracts of Baccharis coridifolia DC.

The in vitro antioxidant and cytotoxic activities in different extracts of Baccharis coridifolia DC. (Compositae) were studied using different bioassays. Antioxidant activity was tested using hydroperoxide-initiated chemiluminescence (CL) in rat liver homogenates. The aqueous extract showed antioxidant activity (IC50 = 141 microg/ml), while the dichloromethane and methanol extracts were prooxidant. Activity in the aqueous extract was confirmed by determination of thiobarbituric acid-reactive substances (TBARS), showing an IC50 = 556 microg/ml. On the other hand, studies on the cytotoxic activity demonstrated a 78% crown gall tumour inhibition and an ED50 = 4. 2 microg/ml in KB cells growth for the dichloromethane extract. A 56% decrease in the initial absorbance of DNA-Methyl Green complex could also be observed at 1000 microg/ml, suggesting the presence of compounds that interact with DNA.

4-Nerolidylcatechol from Pothomorphe spp. scavenges peroxyl radicals and inhibits Fe(II)-dependent DNA damage.

The total reactive antioxidant potential (TRAP) and total antioxidant reactivity (TAR) of 4-nerolidylcatechol (4-NC) and methanolic extracts of Pothomorphe umbellata and P. peltata were determined by monitoring the intensity of luminol enhanced chemiluminescence by peroxyl radicals derived from thermolysis of 2,2'-azobis(2-amidinopropane). The highest antioxidant potential was measured in the extract of P. umbellata (TRAP = 97.2 microM) while the highest reactivity was observed in the extract of P. peltata (TAR = 5.0 microM), measured as equivalents of Trolox concentration. These results were higher than those obtained for 4-NC (TRAP = 33.6 microM, TAR = 4.9 microM). DNA sugar damage induced by Fe(II) salts was also used to determine the capacity of 4-NC to suppress hydroxyl radical-mediated degradation of DNA. Calculated IC50 values for 4-NC and catechin, used as a standard, were 25 and 17 microM, respectively.

Ritual and medicinal plants of the Ese'ejas of the Amazonian rainforest (Madre de Dios, Perú).

The Ese'eja is a hunter-fisher-gatherer tribe of Amerindians which occupies the south-eastern part of Perú. Their culture cannot be disassociated from religious beliefs. Disease can be caused by accident, distraction or indolence, or by evil powers. These evil powers come either from the direct action of a harmful shaman or by interactions with the Devil. A description of shamanic practices is given to elucidate the position of health practices in Ese'eja culture, which includes the use of medicinal and ritual plants. Aspects of ayahuasca (Banisteriopsis caapi (Spruce) Morton, Malpighiaceae) ritual in shaman initiation and in healing rituals are presented. Diagnosis and treatment include invocation to the ayahuasca spirit. Plants used as medicine or invoked for healing are presented.

Studies on the cytotoxicity, antimicrobial and DNA-binding activities of plants used by the Ese'ejas.

Thirty-nine extracts of 13 plants used traditionally as medicinal by the Ese'ejas were studied in order to determine their cytotoxic effect in the brine shrimp. Infusions showed no toxicity. Those plants that tested positive for methanolic and dichloromethane extracts were assayed for DNA-binding activity. Cytotoxicity was not due to the presence of compounds that interact with DNA. Antimicrobial activity of plants used to treat infectious diseases was also performed for the decoctions. These proved to be active against some of the test microrganisms used in the assay.

[Antimicrobial activity and interaction with DNA of medicinal plants from the Peruvian Amazon region]. / Actividad antimicrobiana e interacción con el ADN de plantas medicinales de la Amazonia peruana.

Decoctions of four plants used for the treatment of different infections by indigenous groups of the Peruvian Amazon, i.e. Abuta grandifolia, Cyperus articulatus, Gnaphalium spicatum and Pothomorphe peltata were evaluated for antimicrobial activity by the "stroke method" in agar plates. Tested organisms included Staphylococcus aureus, Escherichia coli, Salmonella gallinarum, Klebsiella pneumoniae, Candida albicans, Pseudomonas aeruginosa and Mycobacterium gordonae. All decoctions showed antimicrobial activity against at least one of the tested organisms. The A. grandifolia and C. articulatis decoctions partially inhibited the growth of P. aeruginosa. S. aureus was completely inhibited by C. articulatus decoction and only partially inhibited by G. spicatum and P. peltata. The A. grandifolia decoction also showed a partial inhibition against M. gordonae, showing a clear correlation between the ethnopharmacological use and the observed activity. Methanolic extracts of plants were analyzed by using the DNA-methyl green bioassay. The methanolic extract of P. peltata (concentration 1000 micrograms/ml) showed a decrease of 30% regarding to the initial absorbance of the DNA-MG complex suggesting the possible interaction with DNA.

Bioactivity of certain medicinal latexes used by the Ese'ejas.

Latexes from Croton erythrochilus, Ficus inspidia and Sapium marmieri used traditionally as medicinal by the Ese'ejas were analyzed for bioactivity. The assays run were: the brine shrimp toxicity microplate bioassay, the wheat rootlet growth inhibition and the DNA-methyl green bioassay. The three latexes showed cytotoxicity to the brine shrimp and concentration-related growth inhibition. No interaction with the DNA-methyl green complex was observed with any of the three latex samples. The field bioassays described has demonstrated to be useful for supporting ethnobotanical information.

Actividad antimicrobiana e interacción con el ADN de plantas medicinales de la Amazonia peruana. / [Antimicrobial activity and interaction with DNA of medicinal plants from the Peruvian Amazon region]

Decoctions of four plants used for the treatment of different infections by indigenous groups of the Peruvian Amazon, i.e. Abuta grandifolia, Cyperus articulatus, Gnaphalium spicatum and Pothomorphe peltata were evaluated for antimicrobial activity by the [quot ]stroke method[quot ] in agar plates. Tested organisms included Staphylococcus aureus, Escherichia coli, Salmonella gallinarum, Klebsiella pneumoniae, Candida albicans, Pseudomonas aeruginosa and Mycobacterium gordonae. All decoctions showed antimicrobial activity against at least one of the tested organisms. The A. grandifolia and C. articulatis decoctions partially inhibited the growth of P. aeruginosa. S. aureus was completely inhibited by C. articulatus decoction and only partially inhibited by G. spicatum and P. peltata. The A. grandifolia decoction also showed a partial inhibition against M. gordonae, showing a clear correlation between the ethnopharmacological use and the observed activity. Methanolic extracts of plants were analyzed by using the DNA-methyl green bioassay. The methanolic extract of P. peltata (concentration 1000 micrograms/ml) showed a decrease of 30

regarding to the initial absorbance of the DNA-MG complex suggesting the possible interaction with DNA.

Actividad antimicrobiana e interacción con el ADN de plantas medicinales de la Amazonia peruana / [Antimicrobial activity and interaction with DNA of medicinal plants from the Peruvian Amazon region]

Decoctions of four plants used for the treatment of different infections by indigenous groups of the Peruvian Amazon, i.e. Abuta grandifolia, Cyperus articulatus, Gnaphalium spicatum and Pothomorphe peltata were evaluated for antimicrobial activity by the [quot ]stroke method[quot ] in agar plates. Tested organisms included Staphylococcus aureus, Escherichia coli, Salmonella gallinarum, Klebsiella pneumoniae, Candida albicans, Pseudomonas aeruginosa and Mycobacterium gordonae. All decoctions showed antimicrobial activity against at least one of the tested organisms. The A. grandifolia and C. articulatis decoctions partially inhibited the growth of P. aeruginosa. S. aureus was completely inhibited by C. articulatus decoction and only partially inhibited by G. spicatum and P. peltata. The A. grandifolia decoction also showed a partial inhibition against M. gordonae, showing a clear correlation between the ethnopharmacological use and the observed activity. Methanolic extracts of plants were analyzed by using the DNA-methyl green bioassay. The methanolic extract of P. peltata (concentration 1000 micrograms/ml) showed a decrease of 30

regarding to the initial absorbance of the DNA-MG complex suggesting the possible interaction with DNA.