Removal of high lead concentration by hydroponic cultures of normal and transformed plants of Scirpus americanus Pers.

Lead is a very toxic metal which affects human health. An alternative to remove it from contaminated water is the use of macrophytes, as Scirpus americanus Pers. This species is tolerant to salt and metals and has high biomass. The present research analyzed the capacity of hydroponic cultures of normal and transgenic plants (line T12) from S. americanus to remove high concentrations of lead. The antioxidant response of plants to metal exposure was also measured. The MINTEQ3.1 program was used to define the media composition in order to have the metal available to the plants. According to MINTEQ3.1 predictions, sulfate, phosphate, and molybdenum must be removed from the medium to avoid lead precipitation. Therefore, the plants were maintained in a modified Hoagland solution containing 100, 250, and 400 mg/L lead. The presence of metal did not affect the growth of roots and stems at all concentration tested. The normal and T12 plants accumulated 69,389 mg/kg and 45,297 mg/kg lead, respectively, and could be considered hyperaccumulators. Plant tolerance to lead mainly involved an increase in superoxide dismutase activity and glutathione accumulation. The bioconcentration factor indicated that S. americanus plants bioconcentrated between 192 and 300 times the metal; thus, S. americanus could be used for phytoremediation of water contaminated with a high concentration of lead.

Cacti for production of metabolites: current state and perspectives.

The Cactaceae family is native from the American continent but is distributed in the arid and semiarid regions worldwide. Cacti exhibit different morphological (succulent body, extended root system, presence of spines, thick waterproof epidermis) and physiological adaptations (crassulacean acid metabolism) that allow growth in adverse conditions intolerable for most C3 and C4 crops. In addition, these plants produce a wide range of secondary metabolites involved in defense mechanism against biotic and abiotic stresses. The present review focused on the content of alkaloids, phenolic compounds, and terpenes present in cacti plants. Data were limited to those compounds clearly characterized by chromatographic and/or spectrometric techniques in both globular and columnar cacti. Additional information about their pharmacological or biological activities, validated by in vitro or in vivo assays, is also presented. Data revealed that the level of some chemical constituents could give value added to these species from a nutritional, pharmacological, and biological point of view.

Enhanced production and identification of antioxidants in in vitro cultures of the cacti Mammillaria candida and Turbinicarpus laui.

Cacti are an important source of metabolites but present limitations for their commercial exploitation, like slow growth and a decrease of wild populations. An alternative to obtain their biocompounds without affecting the natural environment are the in vitro culture techniques. We established in vitro cultures from Mammillaria candida Scheidweiler and Turbinicarpus laui Glass and Foster and used different stresses to increase metabolites and antioxidant activity. The cultures were exposed to 1.25% polyethylene glycol to induce a moderate drought stress, 50 g L-1 sucrose to generate an osmotic stress, chitosan (1.25 to 5 mg mL-1) to simulate a biotic attack, or to UV light. Chitosan was the best elicitor improving 1.5 times the concentration of phenolics, 9 to 10 times the content of flavonoids and betalains, and 16% the antioxidant activity in M. candida suspensions. In T. laui suspensions, this elicitor duplicates the flavonoids content and antioxidant activity. The antioxidant levels in elicited suspensions increased 5 to 10 times in relation to plant tubercles. Eleven compounds were identified in M. candida suspensions being digalloyl rhamnoside and epicatequin gallate the most abundant; in the T. laui suspensions, 16 compounds were detected and the most abundant were 17-decarboxi neobetanin and derivatives of luteolin. Thus, cacti in vitro culture is an efficient system to obtain high level of metabolites of biological interest.

Comparative shotgun proteomic analysis of wild and domesticated Opuntia spp. species shows a metabolic adaptation through domestication.

UNLABELLED: The Opuntia genus is widely distributed in America, but the highest richness of wild species are found in Mexico, as well as the most domesticated Opuntia ficus-indica, which is the most domesticated species and an important crop in agricultural economies of arid and semiarid areas worldwide. During domestication process, the Opuntia morphological characteristics were favored, such as less and smaller spines in cladodes and less seeds in fruits, but changes at molecular level are almost unknown. To obtain more insights about the Opuntia molecular changes through domestication, a shotgun proteomic analysis and database-dependent searches by homology was carried out. >1000 protein species were identified and by using a label-free quantitation method, the Opuntia proteomes were compared in order to identify differentially accumulated proteins among wild and domesticated species. Most of the changes were observed in glucose, secondary, and 1C metabolism, which correlate with the observed protein, fiber and phenolic compounds accumulation in Opuntia cladodes. Regulatory proteins, ribosomal proteins, and proteins related with response to stress were also observed in differential accumulation. These results provide new valuable data that will help to the understanding of the molecular changes of Opuntia species through domestication. BIOLOGICAL SIGNIFICANCE: Opuntia species are well adapted to dry and warm conditions in arid and semiarid regions worldwide, and they are highly productive plants showing considerable promises as an alternative food source. However, there is a gap regarding Opuntia molecular mechanisms that enable them to grow in extreme environmental conditions and how the domestication processes has changed them. In the present study, a shotgun analysis was carried out to characterize the proteomes of five Opuntia species selected by its domestication degree. Our results will help to a better understanding of proteomic features underlying the selection and specialization under evolution and domestication of Opuntia and will provide a platform for basic biology research and gene discovery.

Dietary cladode powder from wild type and domesticated Opuntia species reduces atherogenesis in apoE knock-out mice

Dietary intake of Opuntia species may prevent the development of cardiovascular diseases. The present study was designed to characterize the biological antioxidant and anti-inflammatory properties of Opuntia species and to investigate whether Opuntia cladodes prevent the development of atherosclerosis in vivo, in apoE−KO mice. The effects of the two Opuntia species, the wild Opuntia streptacantha and the domesticated Opuntia ficus-indica, were tested on the generation of intra- and extracellular reactive oxygen species (ROS) production and kinetics of the LDL oxidation by murine CRL2181 endothelial cells and on the subsequent inflammatory signaling leading to the adhesion of monocytes on the activated endothelium and the formation of foam cells. Opuntia species blocked the extracellular ROS (superoxide anion) generation and LDL oxidation by CRL2181, as well as the intracellular ROS rise and signaling evoked by the oxidized LDL, including the nuclear translocation of the transcription factor NFκB, the expression of ICAM-1 and VCAM-1 adhesion molecules, and the adhesion of monocytes to CRL2181. In vivo, Opuntia significantly reduced the formation of atherosclerotic lesions and the accumulation of 4-hydroxynonenal adducts in the vascular wall of apoE-KO mice, indicating that Opuntia cladodes prevent lipid oxidation in the vascular wall. In conclusion, wild and domesticated Opuntia species exhibit antioxidant, anti-inflammatory, and antiatherogenic properties which emphasize their nutritional benefit for preventing cardiovascular diseases (AU)

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Dietary cladode powder from wild type and domesticated Opuntia species reduces atherogenesis in apoE knock-out mice.

Dietary intake of Opuntia species may prevent the development of cardiovascular diseases. The present study was designed to characterize the biological antioxidant and anti-inflammatory properties of Opuntia species and to investigate whether Opuntia cladodes prevent the development of atherosclerosis in vivo, in apoE(-)KO mice. The effects of the two Opuntia species, the wild Opuntia streptacantha and the domesticated Opuntia ficus-indica, were tested on the generation of intra- and extracellular reactive oxygen species (ROS) production and kinetics of the LDL oxidation by murine CRL2181 endothelial cells and on the subsequent inflammatory signaling leading to the adhesion of monocytes on the activated endothelium and the formation of foam cells. Opuntia species blocked the extracellular ROS (superoxide anion) generation and LDL oxidation by CRL2181, as well as the intracellular ROS rise and signaling evoked by the oxidized LDL, including the nuclear translocation of the transcription factor NFκB, the expression of ICAM-1 and VCAM-1 adhesion molecules, and the adhesion of monocytes to CRL2181. In vivo, Opuntia significantly reduced the formation of atherosclerotic lesions and the accumulation of 4-hydroxynonenal adducts in the vascular wall of apoE-KO mice, indicating that Opuntia cladodes prevent lipid oxidation in the vascular wall. In conclusion, wild and domesticated Opuntia species exhibit antioxidant, anti-inflammatory, and antiatherogenic properties which emphasize their nutritional benefit for preventing cardiovascular diseases.

Antiatherogenic and antitumoral properties of Opuntia cladodes: inhibition of low density lipoprotein oxidation by vascular cells, and protection against the cytotoxicity of lipid oxidation product 4-hydroxynonenal in a colorectal cancer cellular model

Opuntia species have been used for thousands of years as a folk medicine in the treatment of diseases. However, the components and protective mechanisms are still unclear. We make the hypothesis that Opuntia species may protect the development of oxidative stress-associated diseases, such as atherosclerosis or colon cancer, via their antioxidant properties. We investigated the protective effect of Opuntia cladode powder against the oxidation of low-density lipoprotein (LDL) evoked by vascular endothelial cells, an important risk factor for atherosclerosis development, and the toxicity of 4-hydroxynonenal (a major lipid peroxidation product) on normal (Apc +/+) and preneoplastic (Apc min/+) immortalized epithelial colon cells. Various Opuntia species classified according to their degree of domestication, from the wildest (Opuntia streptacantha, Opuntia hyptiacantha, Opuntia megacantha), medium (Opuntia albicarpa), to the most domesticated (Opuntia ficus-indica) were tested. Cladode powders prepared from these Opuntia species significantly inhibited LDL oxidation induced by incubation with murine endothelial cells and the subsequent foam cell formation of RAW 264.7 murine macrophages and cytotoxicity on murine endothelial cells. Moreover, Opuntia cladode powder blocked the promotion of colon cancer development on an in vitro model of colonocytes. It may be noted that the phenolic acid and flavonoids content, the antioxidant capacity, and the protective effect were relatively similar in all the cladode powders from wild (O. streptacantha) and domesticated Opuntia. Altogether, these data confirm the therapeutic potential of Opuntia cladodes in diseases associated with oxidative stress

Fluoride bioaccumulation by hydroponic cultures of camellia (Camellia japonica spp.) and sugar cane (Saccharum officinarum spp.).

The ability of hydroponic cultures of camellia and sugar cane adult plants to remove fluoride was investigated. Plants were grown in a 50% Steiner nutrient solution. After an adaptation period to hydroponic conditions, plants were exposed to different fluoride concentrations (0, 2.5, 5 and 10 mg L(-1)). Fluoride concentration in the culture medium and in tissues was measured. In sugar cane, fluoride was mainly located in roots, with 86% of it absorbed and 14% adsorbed. Sugar cane plants removed 1000-1200 mg fluoride kg(-1) dry weight. In camellia plants the highest fluoride concentration was found in leaf. Roots accumulated fluoride mainly through absorption, which was 2-5 times higher than adsorption. At the end of the experiment, fluoride accumulation in camellia plants was 1000-1400 mgk g(-1) dry weight. Estimated concentration factors revealed that fluoride bioaccumulation is 74-221-fold in camellia plants and 100-500-fold in sugar cane plants. Thus, the latter appear as a suitable candidate for removing fluoride from water due to their bioaccumulation capacity and vigorous growth rate; therefore, sugar cane might be used for phytoremediation.

Removing heavy metals by in vitro cultures.

In vitro roots cultures of Typha latifolia and Scirpus americanus aquatic plants have the capacity to remove Pb (II), Mn (II), and Cr (III) from the culture medium. Both species remove Cr and Pb by an absorption process, while Mn is mainly adsorbed to the root surface. This chapter describes a protocol for the establishment of in vitro roots cultures (nontransformed) from T. latifolia and S. americanus, and the procedure for the uptake analysis of Pb (II), Mn (II), and Cr (III) by roots.

Lead, chromium and manganese removal by in vitro root cultures of two aquatic macrophytes species: Typha latifolia L. and Scirpus americanus pers.

The ability of in vitro roots cultures of Typha latifolia and Scirpus americanus to remove metals was studied. Roots were cultivated on Murashige-Skoog medium with 15 microg L(-1) Cr 11, 60 microg L(-1) Pb II or 1.8 mg L(-1) Mn II. Adsorbed metal to root surface was removed by washing with 0.042% HNO3. T. latifolia roots were able to uptake 68.8 microg Pb g(-1), 22.1 microg Cr g(-1) and 1680 microg Mn g(-1), while the S. americanus roots removed 148.3 microg Pb g(-1), 40.7 microg Cr g(-1) and 4037 microg Mn g(-1). About 80-90% of Pb and Cr were absorbed in both cultures. On the contrary, the Mn removal was due mainly to an adsorption process (82-86%). In comparison to the T. latifolia cultures, S. americanus cultures were twofold more efficient to remove Pb and Cr, and threefold more efficient to remove Mn. Both plant species capture metals in the following order: Cr >Pb >Mn. This investigation confirms that in vitro roots cultures could be an alternative as a phytoremediation approach for contaminated water with heavy metals.

Induction of in vitro roots cultures of Thypha latifolia and Scirpus americanus and study of their capacity to remove heavy metals

We have established the conditions to obtain in vitro root cultures of Thypha latifolia and Scirpus americanus and have investigated their capacity to remove Pb(II), Mn(II) and Cr(III) from the culture medium. The best conditions for the in vitro culture growth were: an inoculum of 0.2 g of T. latifolia roots and 0.05 g of S. americanus roots (fresh weight), Murashige-Skoog medium and 2 mg L-1of indolacetic acid. The T. latifolia and S. americanus root cultures were cultivated onto media containing Cr (15 µg L-1), Pb (60 µg L-1) or Mn (1.8 mg L-1). Both species were able to remove Pb and Cr near to 100% and 71-100% of Mn from the medium solution during the 6-8 days of experimentation. According to metal concentrations removed from the medium containing the growing root mass, the in vitro root culture of S. americanus can be considered as an accumulator for Pb (157.73 µg g-1), Cr (55.6 µg g-1) and Mn (5000 µg g-1).