Inhibition of the CYP Enzymatic System Responsible of Heterocyclic Amines Bioactivation by an Asclepias subulata Extract

Asclepias subulata plant extract has previously demonstrated antiproliferative activity and antimutagenicity against heterocyclic aromatic amines (HAAs) commonly found in cooked meat. The objective of this work was to evaluate the in vitro ability of an ethanolic extract from the medicinal plant Asclepias subulata extract (ASE), non-heated and heated (180 °C), to inhibit the activity of CYP1A1 and CYP1A2, which are largely responsible for HAAs bioactivation. Ethoxyresorufin and methoxyresorufin O-dealkylation assays were performed in rat liver microsomes exposed to ASE (0.002-960 µg/mL). ASE exerted an inhibitory effect in a dose-dependent manner. The half inhibitory concentration (IC₅₀) for unheated ASE was 353.6 µg/mL and 75.9 µg/mL for heated ASE in EROD assay. An IC₄₀ value of 288.4 ± 5.8 µg/mL was calculated for non-heated ASE in MROD assay. However, after heat treatment, the IC₅₀ value was 232.1 ± 7.4 µg/mL. Molecular docking of corotoxigenin-3-O-glucopyranoside, one of the main components of ASE, with CYP1A1/2 structure, was performed. Results show that the interaction of corotoxigenin-3-O-glucopyranoside with CYP1A1/2s' α-helices, which are related with the active site and the heme cofactor, may explain the plant extract's inhibitory properties. Results showed that ASE inhibits CYP1A enzymatic subfamily and may potentially act as a chemopreventive agent by inhibiting bioactivation of promutagenic dietary HAAs.

N-(2-ozoazepan-3-yl)-pyrrolidine-2-carboxamide, a novel Octopus vulgaris ink-derived metabolite, exhibits a pro-apoptotic effect on A549 cancer cell line and inhibits pro-inflammatory markers

This research aimed to chemically synthesize and evaluate the antiproliferative and anti-inflammatory potential of ozopromide (OPC), a novel compound recently isolated from O. vulgaris ink. After chemical synthesis, OPC structural characterization was confirmed by COSY2D, FTIR, and C-/H-NMR. OPC inhibited the growth of human breast (MDA-MB-231), prostate (22Rv1), cervix (HeLa), and lung (A549) cancerous cells, being the highest effect on the latter (IC₅₀: 53.70 μM). As confirmed by flow cytometry, OPC induced typical apoptosis-derived morphological features on A549 cells, mostly at early and late apoptosis stages. OPC generated a dose-dependent effect inhibiting IL-6 and IL-8 on LPS-stimulated peripheral mononuclear cells (PBMCs). A major affinity of OPC to Akt-1 and Bcl-2 proteins in silico agreed with the observed pro-apoptotic mechanisms. Results suggested that OPC has the potential to alleviate inflammation and be further studied for anticancer activity. Marine-derived food products such as ink contains bioactive metabolites exhibiting potential health benefits.

Microencapsulation of phenolic extract from sea grape (Coccoloba uvifera L.) with antimutagenic activity

This study aimed to microencapsulate the sea grape ethanolic extract by the spray drying process, characterizing the obtained powder, and evaluating its antimutagenicity activity. Microparticles showed a mean size of 6.28 µm and a spherical shape with a smooth surface. The powder had a low moisture content (4.02 ± 0.92%) and water activity (0.27 ± 0.01), and high solubility (76 ± 3.60%). Moreover, hygroscopicity (14.75 ± 2.63 g/100 g of powder) and bulk density (0.63 ± 0.03 g/cm3) values suggested that this powder can be easily handled at a pilot or industrial scale. In addition, microencapsulation protected the extract against oxidation by ultraviolet light, improved its thermal stability, and its antimutagenicity activity was similar to fresh sea grape extract. In conclusion, the microencapsulation with maltodextrin by spray drying technique is an alternative to protect bioactive compounds from sea grapes against environmental conditions, maintaining their antimutagenic activity.

ISOLATION AND IDENTIFICATION OF A NEW ANTIPROLIFERATIVE INDOLOCARBAZOLE ALKALOID DERIVATIVE EXTRACTED FROM FARMED SHRIMP (Litopenaeus vannamei) MUSCLE

Farmed shrimp Litopenaeus vannamei, one of the most consumed seafood in the planet, is a source of antiproliferative extracts still to be fully characterized. This study the isolation and identification of these antiproliferative compounds. From a chloroform-soluble extract from shrimp muscle, hexane- and methanol-soluble fractions were obtained and tested for antiproliferative activity (MTT), a bioassay that guided the fractionation and isolation of bioactive fractions using open column chromatography. MeOH-soluble fraction resulted bioactive and was subjected to further fractionation from which one subfraction outstand for being highly active against prostate cancer cell line. Antiproliferative effects were evaluated using colorimetric assays and cell morphology observations. Further chromatographic procedures resulted in sub-fractions from which one was effective in causing DNA damage and F-actin polymerization, which suggests cellular collapse and apoptosis. According to the structural chemical characterization carried out, dioctyl phthalate, eicosapentaenoic acid, and an indolocarbazole alkaloid type of compound were identified. This last compound, which resulted majorly responsible for the bioactivity, was not found reported in the available databases. Pure EPA control was used to compare it with the subfraction, observing greater activity in the subfraction than when EPA was used, suggesting that another compound different from EPA is providing the highest activity; but, more investigation is needed for a full chemical and structural characterization.

Mathematical modeling for ethanol, methanol and acetaldehyde generation through Mexican carignane grape (Vitis vinifera) vinification process

Wine is a worldwide known beverage, and even though its consumption has been associated with the reduction of heart diseases and the extent of lifespan, it also has compounds that might cause adverse effects on human health such as methanol and acetaldehyde. The aim of this study was to determine the effect of time, temperature, and pectic enzymes over wine methanol and acetaldehyde concentrations during vinification. Three temperatures (20, 30, and 35 °C) and three pectic enzyme concentrations (0, 9, and 18 mL/Kg) were tested, letting fermentation to stop due to sugar depletion. Both, metanol and acetaldehyde were quantified throughout the fermentation process. Temperature reduced metanol production, observing the lowest metanol concentration (53.543 ± 3.267 mg/100 mL of wine) at 35 °C in the absence of pectic enzyme. Acetaldehyde was not affected by these variables. Alcohol, metanol, and acetaldehyde concentrations were adjusted to mathematical models with high correlations.

Octopus vulgaris ink extracts exhibit antioxidant, antimutagenic, cytoprotective, antiproliferative, and proapoptotic effects in selected human cancer cell lines

Cancer is a noncommunicable disease of rising worldwide concern. Marine food products such as Octopus vulgaris ink (OI) could be sources of compounds addressing these concerns. This study aimed to evaluate the antimutagenic, cytoprotective, antiproliferative, proapoptotic, and antioxidant capacity of OI extracts on human cancer cell lines (22Rv1, HeLa, A549). The ARPE-19 cell line was used as a reference human cell line to evaluate the ink's cytotoxicity. The water extract exhibited the highest antimutagenic and cytoprotective effect, but the dichloromethane extract (DM) showed the lowest half lethal concentration against 22Rv1 cells. Structural elucidation of purified DM fractions (F1, F2, F3) identified an unreported compound, N-(2-ozoazepan-3-yl)-pyrrolidine-2-carboxamide (OPC). DM-F2 showed high antiproliferative effect (LC₅₀ = 27.6 µg/mL), reactive species modulation, early-apoptosis induction (42.9%), and nuclei disruption in 22Rv1 cells. In silico analysis predicted high OPC affinity with Cyclin D1 (-6.70 kcal/mol), suggesting its potential impact on cell cycle arrest. These results highlight the antimutagenic, cytoprotective, and antiproliferative potential health benefits derived from underutilized marine food products such as OI. Further investigations at in vitro or in vivo levels are required to elucidate mechanisms and health benefits from OI. PRACTICAL APPLICATION: O. vulgaris ink is an underutilized marine natural product that could be a source of biological compounds with potential health benefits such as antioxidant activity and cancer prevention.

Antimutagenic, Antiproliferative and Antioxidant Properties of Sea Grape Leaf Extract Fractions (Coccoloba uvifera L.)

BACKGROUND

Cancer is a disease characterized by the invasion and uncontrolled growth of cells. One of the best ways to minimize the harmful effects of mutagens is through the use of natural antimutagens. In this regard, the search for new antimutagens that act in the chemoprevention could represent a promising field in this area. <p >Objective: In this study biological potential of 11 fractions from Coccoloba uvifera L. leaf hexane extract was evaluated by several in vitro tests.

METHODS

Leaves were lyophilized and hexane extraction was performed. The extract was fractionated by column chromatography with hexane, ethyl acetate, and methanol. The antimutagenic (Ames test), antiproliferative (MTT test), and antioxidant capacity (DPPH, ABTS, and ferrous ion chelation) of the fractions were evaluated.

RESULTS

Fractions 4, 6, 8, and 9 have antimutagenic activity (against sodium azide in strain TA100), fraction 11 showed antiproliferative capacity (IC50 of 24 ± 9 μg/mL in cells of HCT 116). The fractions with the highest activity were analyzed by HPLC-MS and lupeol, acacetin, and β-sitosterol were identified.

CONCLUSION

This study demonstrates, for the first time, the bioactivity of C. uvifera leaf as a new source of high biological value compounds (HBVC), which can be of interest to the food and pharmaceutical industries.

Phytotoxicity, cytotoxicity, and in vivo antifungal efficacy of chitosan nanobiocomposites on prokaryotic and eukaryotic cells

Chitosan (CS) nanosystems have potential applications for the control of microorganisms in the medical, environmental, and agrifood fields. In vivo and in vitro assays of CS nanosystems have experienced increased activity due to improved physicochemical properties, biological activity, and reactivity. Hence, it is important to determine whether their application involves toxicological risks. The aim of this study was to evaluate the mutagenic, cytotoxic, phytotoxic, and in vivo antifungal activity of chitosan-pyrrole-2-carboxylic acid nanobiocomposites (CS-PCA). The CS-PCA nanoparticles were synthesized by means of the nanoprecipitation technique with a size and ζ-potential of 502 ± 72 nm and + 54.7 ± 15.0 mV, respectively. According to the Ames test, no evidence of mutagenic activity was observed in Salmonella typhimurium strains. The cytotoxic assay showed that the incorporation of PCA into the CS matrix increased the toxic effect on ARPE-19 cells. However, fluorescence microscopy of ARPE-19 cells did not reveal morphostructural changes allusive to cell injury. CS-PCA exhibited strong phytotoxicity on lettuce seeds and the complete inhibition of seed development. The antifungal assay demonstrated that the CS-PCA delayed Aspergillus niger infection in tomato fruit until day 3; however, its use for the pre-treatment of seeds might exert adverse effects on plant development.

Antimutagenic effect of an Asclepias subulata extract against heterocyclic aromatic amines commonly found in cooked meat and its heat stability

The antimutagenicity of an extract from the medicinal plant Asclepias subulata (ASE) against heterocyclic aromatic amines (HAAs) commonly found in cooked meat, as well as its stability to heat treatment (HT), was evaluated. HT (180 °C/3 min) had no effect on the content in ASE of the bioactive compound corotoxigenin-3-O-glucopyranoside; conversely, calotropin significantly decreased by 72%. ASE exerted antimutagenicity against PhIP, MelQ, and MelQx in TA98 and TA100 Salmonella strains, and this activity was not affected by heat, with the exception of MelQ (p < 0.05). Since HAAs can induce colorectal cancer, the thermal stability of ASE's antiproliferative effect against colorectal cancer cells was also evaluated. HT decreased (p < 0.05) the antiproliferative activity of ASE; however, the remaining activity was still strong with an IC₅₀ of 16.8 ± 2.03 µg/mL. Therefore, ASE can be used as a food ingredient to reduce the carcinogenic potential of thermally induced HAAs.

Biosorption of copper by immobilized biomass of Aspergillus australensis. Effect of metal on the viability, cellular components, polyhydroxyalkanoates production, and oxidative stress

Heavy metals are toxic especially when they are introduced into the environment due to anthropogenic activities such as metallurgy, mining, and tanning. Removing these pollutants has become a worldwide concern since they cannot be degraded into nontoxic forms causing extended effects in the ecosystems. The use of an Aspergillus australensis was evaluated in order to remove Cu²⁺ from simulated wastewater. The fungus was isolated from river sludges contaminated with heavy metals and was first evaluated for the determination of Cu²⁺ tolerance levels. Microscopic fluorescence analysis was carried out to determine the effect of Cu²⁺ presence on the viability, cellular components, polyhydroxyalkanoates production, and oxidative stress of the fungus, as a response to the stress caused by exposure to metal. In order to achieve copper removal, the A. australensis biomass was produced using batch cultures, and the mycelium was immobilized on a textile media in order to compare the copper-removal efficiency of live or dead biomass. The optimal values of pH and temperature for biomass production were established by using a surface response analysis. Live immobilized biomass was capable of removing Cu²⁺ from 1.54 ± 0.19 to 2.66 ± 0.26 mg of copper/ g of dry biomass, while values of 1.93 ± 0.03 to 2.36 ± 0.29 mg of copper/g of dry biomass were observed when dead biomass was used. As was expected, copper removal using biomass varied depending on the pH and temperature used.

Antioxidant, Antimutagenic and Cytoprotective Properties of Hydrosos Pistachio Nuts

Pistachio nuts are included among the foods with the highest antioxidant capacity. Stressed cultivating conditions, such as the use of regulated deficit irrigation (RDI), are expected to create a plant response that might increase the production of secondary metabolites. Fruits that are obtained under RDI treatments are commonly called hydroSOS products. The aim of this work was to study the influence of using different rootstocks (P. atlantica, P. integerrima, and P. terebinthus) and two RDI treatments on the antioxidant (ABTS, ferric reducing antioxidant power (FRAP), and DPPH), antimutagenic (Ames test), and cytotoxicity (MTT assay in five human cell lines) activities of pistachios. P. terebinthus showed the best antioxidant activity, and the RDI treatments maintained and improved the antioxidant properties of pistachios. Neither the rootstock nor the RDI had significant impact on the antimutagenic potential of pistachios. The nut extracts had no toxic effect on non-cancerous cells and the application of RDI did not reduce their cytoprotective capacity. Furthermore, neither rootstock nor RDI treatments affected the ability of the pistachio extracts of preventing the oxidative damage by H₂O₂. The application of RDI strategies, in addition to allowing irrigation water saving, led to obtaining pistachios with the same or even better biofunctional characteristics as compared to fully irrigated pistachios.

Toxicological Assessment of Cross-Linked Beads of Chitosan-Alginate and Aspergillus australensis Biomass, with Efficiency as Biosorbent for Copper Removal

Sorbent materials of biological origin are considered as an alternative to the use of traditional methods in order to remove heavy metals. Interest in using these materials has increased over the past years due to their low cost and friendliness to the environment. The objective of this study was to synthesize and characterize cross-linked beads made of chitosan, alginate, and mycelium of a copper-tolerant strain of Aspergillus australensis. The acute toxicity of the biocomposite beads was assessed using brine shrimp Artemia salina nauplii and the phytotoxicity was determined using lettuce (Lactuca sativa) and chili pepper 'Anaheim' (Capsicum annuum) seeds. The biosorption capacity for copper removal in simulated wastewater was also evaluated. Results showed that the biosorbent obtained had a maximal adsorption of 26.1 mg of Cu²⁺ per g of biocomposite, and removal efficiency was around 79%. The toxicity of simulated residual water after treatment with the biocomposite showed low toxicity toward seeds, which was highly dependent on the residual copper concentration. The toxicity of the biocomposite beads to A. salina was considered medium depending on the amount of the biocomposite, which was attributed to low pH. Biocomposite shows promise as biosorbent for the removal process of heavy metals.

PRESENCIA DE ETIL CARBAMATO Y OCRATOXINA A DURANTE LA FERMENTACIÓN DE UVA (Vitis vinifera) CARIGNANE

El vino es una bebida conocida a nivel mundial con más de 500 diferentes tipos de compuestos, algunos relacionados con efectos adversos a la salud tales como la ocratoxina A (OTA) y el etil carbamato (EC). El objetivo de este trabajo fue estudiar la producción de ambos tóxicos durante el proceso de fermentación de uva Carignane. Se monitoreó la disminución de la concentración de azúcares fermentables por medio de un hidrómetro de gravedad específica, la concentración de OTA y EC por medio de HPLC y la identificación de hongos por microcultivo. Se encontró que el tiempo de fermentación está directamente relacionado con la temperatura de fermentación y presentan un comportamiento logarítmico. La concentración de OTA máxima fue de 3.423±0.332 ppm; esta no se ve afectada por tiempo ni temperatura de fermentación, por lo que la presencia de esta micotoxina se debe a su producción por Aspergillus niger en campo; en cuanto al EC, este no se generó bajo las condiciones experimentales utilizadas. Este estudio demuestra que EC y OTA no representan un riesgo a la salud del consumidor bajo las condiciones utilizadas, y para disminuir el riesgo de OTA, se deben tener consideraciones en el campo vitivinícola.

ACTIVIDADES BIOLÓGICAS DEL EXTRACTO METANÓLICO DE Rhodosorus marinus

Las microalgas marinas pueden ser una fuente de moléculas bioactivas; existen numerosos reportes de actividad antioxidante, antibacteriana y antiproliferativa de extractos obtenidos a partir de macroalgas. El objetivo del presente trabajo fue evaluar la actividad citotóxica, antioxidante y antimutagénica del extracto metanólico de la microalga roja Rhodosorus marinus. El extracto fue obtenido a partir de biomasa liofilizada mediante lisis ácida y sonicación. Se evaluó la actividad citotóxica frente a 7 líneas celulares humanas con el ensayo MTT, la actividad antioxidante por ABTS y DPPH y la actividad antimutagénica con las cepas TA98 y TA100 del ensayo de Ames. Se encontró actividad citotóxica frente a 5 de las 7 líneas evaluadas. Los porcentajes de inhibición para la actividad antioxidante fueron de 25.60 + 4.03% (DPPH) y 5.59 + 0.63% (ABTS). Para el ensayo de Ames, frente a ambasm cepas probadas se alcanzaron porcentajes de inhibición de colonias revertantes de aproximadamente el 75% en la concentración más alta evaluada, lo cual indica una fuerte actividad antimutagénica. Los resultados mostraron actividad biológica en las diferentes pruebas realizadas, por lo que se infiere que el extracto metanólico contiene moléculas bioactivas de importancia en la salud y para diferentes usos biotecnológicos.

COMPOUNDS WITH in vitro ANTIBACTERIAL ACTIVITY FROM HYDROSOL OF Lippia palmerI AND MORPHOMETRIC CHANGES ON Listeria monocytogenes

Foodborne diseases have increased, and with it, the interest to discover new natural antimicrobials; the use of aromatic plants, due to the extraction and use of the essential oil (EO), are widely studied and with great biological activity. However, studies with hydrosols (HS) from aromatic plants are limited. The aim in this study was to evaluate the antibacterial activity of HS from Lippia palmeri plant against the bacterial pathogen L. monocytogenes. HS was obtained by hydrodistillation and fractionation thereof by open column chromatography. The antibacterial activity was performed by disk diffusion. The inhibitory concentration (IC50) was estimated using the PROBIT survival analysis. Ampicillin was used as control. To evaluate the diameter and cellular damage, optical microscopy and epifluorescence were used, respectively. The characterization was performed by spectroscopy. HS showed IC50 of 224 μL/mL and from HS two fractions were obtained. The fraction with the highest activity showed an IC50 of 125 mg/mL and rosmarinic acid and a phthalate derivative were identified from this fraction. HS, showed bioactivity against L. monocytogenes. Therefore, this would be a candidate for use as an active ingredient in the disinfection of food and areas in contact with them.

Antimicrobial activity of pomegranate peel extracts as affected by cultivar

BACKGROUND

Some studies have reported that different parts of the pomegranate fruit, especially the peel, may act as potential antimicrobial agents and thus might be proposed as a safe natural alternative to synthetic antimicrobial agents. The high tannin content, especially punicalagin, found in pomegranate extracts, has been reported as the main compound responsible for such antimicrobial activity. Because the pomegranate peel chemical composition may vary with the type of cultivar (sweet, sour-sweet and sour), pomegranates may also differ with respect to their antimicrobial capacity.

RESULTS

The extract from PTO8 pomegranate cultivar peel had the highest antimicrobial activity, as well as the highest punicalagins (α and β) and ellagic acid concentrations. In the results obtained from both antibacterial and antifungal activity studies, the sour-sweet pomegranate cultivar PTO8 showed the best antimicrobial activity, and the highest ellagic acid concentrations.

CONCLUSION

The results of the present study suggest that ellagic acid content has a significant influence on the antimicrobial activity of the pomegranate extracts investigated. The pomegranate peel of the PTO8 cultivar is a good source of antifungal and antibacterial compounds, and may represent an alternative to antimicrobial agents of synthetic origin. © 2016 Society of Chemical Industry.

Biological Activity of Conventional and Organic Pomegranate Juices: Antioxidant and Antimutagenic Potential

None of the health claims about pomegranate juices has been approved yet by European Food Safety Authority (EFSA). There is a general perception among consumers that organic foods are healthier, tastier, and more nutritive than the conventional products. The aim of this research was to study the differences in the biological activity between ready-for-consumption juices obtained from pomegranates fruits grown under conventional and organic agricultural practices. Antioxidant activity has been evaluated by three methods (DPPH^•, ABTS⁺, and FRAP), together with the total contents of phenolics and punicalagin (HPLC-DAD); besides, the Ames test was used to evaluate the antimutagenic potential of the juices. Pomegranate juice, either from conventionally or organically grown fruits, was antimutagenic (mean of 51 and 90 % for Salmonella typhimurium TA100 and TA98, respectively) and it was capable of protecting DNA from both, base-pair or frame-shift type of mutations. In fact, the antimutagenicity of conventional pomegranate juice was higher than that achieved by the organic sample; this finding was linked to a higher punicalagin content (201 and 104 mg L^-1 for conventional and organic juices, respectively).

Antioxidant, antimutagenic and antiproliferative activities in selected seaweed species from Sinaloa, Mexico

Context Seaweeds from the Mexican Pacific Ocean have not been evaluated as a source of chemoprotectants. Objective The objective of this study is to evaluate chemopreventive activities of the seaweeds Phaephyceae - Padina durvillaei (Dictyotaceae) - Rodhophyceae - Spyridia filamentosa (Spyridiaceae), Gracilaria vermiculophylla (Gracilariaceae) - and Chlorophyceae - Ulva expansa (Ulvaceae), Codium isabelae (Codiaceae), Rhizoclonium riparium (Cladophoraceae) and Caulerpa sertularioides (Caulerpaceae). Materials and methods Methanol, acetone and hexane seaweed extracts were assessed at 30 and 3 mg/mL on antioxidant capacity (DPPH and ABTS assays), 0.003-3.0 mg/plate on antimutagenic activity against AFB1 using Salmonella typhimurium TA98 and TA100 tester strains in Ames test, and 12.5 to 100 μg/mL on antiproliferative activity on Murine B-cell lymphoma. Phenols, flavonoids and pigments content were also assessed as antioxidant compounds. Results Extraction yield was higher in methanol than in acetone and hexane extracts (6.4, 2.7 and 1.4% dw). Antioxidant capacity was higher in brown and green than in red seaweed species, particularly in P. durvillaei extracted in acetone (EC50  value= 16.9 and 1.56 mg/mL for DPPH and ABTS). Flavonoids and chlorophylls were identified as mainly antioxidant components; particularly in hexane extracts, which were correlated with the antioxidant capacity. Highest mutagenesis inhibition (> 40%) occurred in R. riparium at the lowest concentration assayed (0.003 mg/plate), while highest antiproliferative inhibition (37 and 72% for 12.5 and 25 μg/mL) occurred in C. sertularioides. Discussion and conclusion Flavonoids and chlorophylls explained the chemopreventive activities assessed in S. filamentosa, R. riparium and C. sertularioides. These seaweeds have a high potential as a source of novel chemoprotectants.

Isolation and structural elucidation of antiproliferative compounds of lipidic fractions from white shrimp muscle (Litopenaeus vannamei)

Shrimp is one of the most popular seafood items worldwide, and has been reported as a source of chemopreventive compounds. In this study, shrimp lipids were separated by solvent partition and further fractionated by semi-preparative RP-HPLC and finally by open column chromatography in order to obtain isolated antiproliferative compounds. Antiproliferative activity was assessed by inhibition of M12.C3.F6 murine cell growth using the MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide) assay. The methanolic fraction showed the highest antiproliferative activity; this fraction was separated into 15 different sub-fractions (M1-M15). Fractions M8, M9, M10, M12, and M13 were antiproliferative at 100 µg/mL and they were further tested at lower concentrations. Fractions M12 and M13 exerted the highest growth inhibition with an IC50 of 19.5 ± 8.6 and 34.9 ± 7.3 µg/mL, respectively. Fraction M12 was further fractionated in three sub-fractions M12a, M12b, and M12c. Fraction M12a was identified as di-ethyl-hexyl-phthalate, fraction M12b as a triglyceride substituted by at least two fatty acids (predominantly oleic acid accompanied with eicosapentaenoic acid) and fraction M12c as another triglyceride substituted with eicosapentaenoic acid and saturated fatty acids. Bioactive triglyceride contained in M12c exerted the highest antiproliferative activity with an IC50 of 11.33 ± 5.6 µg/mL. Biological activity in shrimp had been previously attributed to astaxanthin; this study demonstrated that polyunsaturated fatty acids are the main compounds responsible for antiproliferative activity.

Shrimp lipids: a source of cancer chemopreventive compounds

Shrimp is one of the most popular seafoods worldwide, and its lipids have been studied for biological activity in both, muscle and exoskeleton. Free fatty acids, triglycerides, carotenoids, and other lipids integrate this fraction, and some of these compounds have been reported with cancer chemopreventive activities. Carotenoids and polyunsaturated fatty acids have been extensively studied for chemopreventive properties, in both in vivo and in vitro studies. Their mechanisms of action depend on the lipid chemical structure and include antioxidant, anti-proliferative, anti-mutagenic, and anti-inflammatory activities, among others. The purpose of this review is to lay groundwork for future research about the properties of the lipid fraction of shrimp.

Controlled release matrices and micro/nanoparticles of chitosan with antimicrobial potential: development of new strategies for microbial control in agriculture

The control of micro-organisms responsible for pre- and postharvest diseases of agricultural products, mainly viruses and fungi, is a problem that remains unresolved, together with the environmental impact of the excessive use of chemicals to tackle this problem. Current efforts are focused on the search for efficient alternatives for microbial control that will not result in damage to the environment or an imbalance in the existing biota. One alternative is the use of natural antimicrobial compounds such as chitosan, a linear cationic biopolymer, which is biodegradable, biocompatible and non-toxic, has filmogenic properties and is capable of forming matrices for the transport of active substances. The study of chitosan has attracted great interest owing to its ability to form complexes or matrices for the controlled release of active compounds such as micro- and nanoparticles, which, together with the biological properties of chitosan, has allowed a major breakthrough in the pharmaceutical and biomedical industries. Another important field of study is the development of chitosan-based matrices for the controlled release of active compounds in areas such as agriculture and food for the control of viruses, bacteria and fungi, which is one of the least exploited areas and holds much promise for future research.

In vitro antioxidant and antiproliferative activities of plants of the ethnopharmacopeia from northwest of Mexico

Background

The aim of this study, is to investigate the in vitro antioxidant activity, the total phenols content, the flavonoids content and the antiproliferative activity of methanolic extracts of the plants: Krameria erecta, Struthanthus palmeri, Phoradendron californicum, Senna covesii and Stegnosperma halimifolium, used by different ethnic groups from northwestern Mexico in the treatment and cure of various diseases.

Methods

The in vitro antioxidant activity was measured by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reducing/Antioxidant Power assay (FRAP), the total phenols content was measured by Folin–Ciocalteau assay, the flavonoids content by the AlCl₃ colorimetric method and the antiproliferative activity (line cells HeLa, RAW 264.7, M12A^k.C3.F6 and L929) using MTT method.

Results

The K. erecta extract showed the higher radical scavenging activity (67.88%), antioxidant activity by FRAP (1.41 mg Trolox Eq), the highest total phenols content (598.51 mg Galic Acid Eq/g extract), the highest flavonoids content (3.80 mg Quercetin Eq/g extract) and the greatest antiproliferative activity in a dose dependent manner against most Cell line evaluated. A positive correlation was found between the antioxidant activity and the flavonoids content.

Conclusions

This study is the first report on the antioxidant and antiproliferative activities of the five species evaluated. The results demostrate that there is a positive correlation between antioxidant activity and the flavonoids content, indicating that these type of polyphenols could be the major contributors to the observed antioxidant activity in the evaluated plant extracts. Of the extracts evaluated, that of Krameria erecta showed the greatest antioxidant and antiproliferative activities, a discovery that makes this species a promising candidate for future research.

Seasonal variations in the concentrations of metals in Crassostrea corteziensis from Sonora, México

This study examines seasonal variations in the concentrations of Cd, Cu, Pb, and Hg in experimentally cultured Crassostrea corteziensis, an oyster species known to have high resistance to physical and chemical stressors. The highest levels of Cd (4.92 mg/kg), Cu (3.45 mg/kg), and Pb (0.67 mg/kg) were detected in oyster samples collected during the summer, while Hg concentrations were similar (0.03 to 0.04 mg/kg) throughout all seasons. Results indicate that except for Cd, Crassostrea corteziensis accumulates metals to levels below those recommended by the US. FDA and the Mexican government. For Cd, its concentration correlates more strongly with the temperature of the oyster's environment rather than to the oyster growth cycle.

Insecticide residues in stored grains in Sonora, Mexico: quantification and toxicity testing

Food safety has acquired great attention by food importer and exporters. Food rejection or acceptance across international borders is based on the compliance with international food regulations. Due to the lack of recent data on pesticide residues in Mexican grains, this study focused on detecting and quantifying insecticide residues in stored wheat, corn, chickpeas, and beans, as well as to determine their mutagenic potential. Grains were sampled from primary storage sites in Sonora, Mexico. Malathion, chlorpyrifos, deltamethrin, cypermethrin, 4,4-DDE, 4,4-DDD and 4,4-DDT were analyzed in 135 samples. Grain samples were not mutagenic and most pesticide levels were within regulation limits.

Partial chemical/structural elucidation of anti-mutagenic compounds from corn

In this study, corn fractions obtained from an isolation process of anti-mutagenic factors in our previous research work (Burgos-Hernández et al., 2001), were subjected to several analyses for chemical/structural elucidation. The anti-mutagenic activity of these fractions was tested against aflatoxin B(1) (AFB(1)) and 1-methyl-3-nitro-1-nitrosoguanidine (MNNG), a mutagen that does not require bioactivation. Two concentrations of this agent in the corn fractions were tested for anti-mutagenicity in the Salmonella/microsomal mutagenicity assay, using tester strain TA100 with no metabolic activation. Corn fractions tested showed evidence of anti-mutagenic activity by producing a dose-response type of relationship between a constant amount of MNNG and several concentrations of tested corn fraction. Five different varieties of yellow corn were tested in order to determine if the anti-mutagenic factors were intrinsic to corn. Variety of the corn did not show an effect on the reduction of the mutagenic potential of AFB(1) suggesting that anti-mutagenic compounds are intrinsic to corn. Four corn fractions, previously obtained after the isolation process were analyzed by MALDI-MS and GC-MS. MALDI-MS showed the presence of two groups of molecules or molecular fragments. The molecular mass of one group ranged from 250 to 370 m/z, the other ranged from 540 to 640 m/z. GC-MS identified linoleic acid as one of the compounds responsible for the anti-mutagenic activity present in corn.

Anti-mutagenic compounds from corn

In previous studies with aflatoxin-contaminated corn an uncharacteristic response for AFB1 in the Salmonella/microsomal mutagenicity assay (Ames test) was observed and the presence of anti-aflatoxin factors in the corn was suggested. In the current study, corn was extracted and fractionated using thin layer chromatography (TLC) using different developing solvent systems and the Ames test was used to monitor for anti-mutagenic activity in the corn fractions. Both Salmonella tester strains TA98 and TA100 with metabolic activation (S9) were used. Several corn fractions, at different stages in the isolation and purification process, showed anti-mutagenic dose-responses when exposed to pure AFB1. Corti extracts were non-toxic to the tester strains and TLC fractions that showed the best anti-mutagenic dose-responses were selected for further partial characterization analyses.