Synergistic effect of drying methods and ultrasonication on natural deep eutectic solvent extraction of phytochemicals from African spinach (Amaranthus hybridus) stem.

The study evaluated the combined effects of drying methods (air drying [AD], hot AD [HAD], microwave drying [MD], and freeze-drying [FD]) and ultrasonication parameters (sonication temperature [STemp]: 40, 50, and 60°C) and heating time (STime: 60 and 120 min) on natural deep eutectic solvent (NADES) extraction of phytochemicals from Amaranthus hybridus stem. Increasing the STemp increased the extraction yield (ECY) of the phytochemicals for all drying methods but increase in the heating time reduced the ECY slightly. MD combined with 60°C ST showed the highest ECY (53%), whereas HAD combined with 40°C ST had the lowest ECY (18%). At 60 min heating time, increasing the ST from 40 to 50°C increased the total phenolic content (TPC) in the extract for most drying methods except MD, and a sonication time of 120 min showed a slightly higher TPC, especially for MD samples. At 60 min sonication, total flavonoid content (TFC, 800 mgQE/g) was highest for AD plus 50°C ST and lowest for AD combined with 60°C (100 mgQE/g), whereas for 120 min sonication, MD and AD with 50°C showed the highest TFC (690 mgQE/g). FD retained better some of the vitamins (thiamine, riboflavin, niacin) but MD retained better vitamin C. The antioxidant capacity was not so much different among the drying methods except for FD, which showed lower values. These results provide a theoretical basis for the synergistic applications of drying and ultrasonication during NADES extraction of phytochemicals from Amaranthus hybridus.

Antifungal Potency of Amaranth Leaf Extract: An In Vitro Study.

Plant diseases are a serious problem for agricultural crops, the food industry and human health. Significant efforts have been made in recent years to find natural products that could reduce the growth of plant pathogens and improve food quality. At present, there is an increased interest in plants as a source of biological active compounds that can protect crops from diseases. Important sources of these phytochemicals are lesser-known pseudocereals such as amaranth. The objective of this study was to determine the antifungal activity of leaf extracts of four amaranth species (A. cruentus, A. hypochondriacus × hybridus, A. retroflexus and A. hybridus). The antifungal potency of amaranth extracts was analyzed against selected strains of fungi. The results suggested that the antimicrobial properties of the tested extracts varied depending on the amaranth species and the fungal strain. The studied extracts inhibited the growth of Fusarium equiseti, Rhizoctonia solani, Trichoderma harzianum and Alternaria alternata. A lower inhibitory effect of the extracts was recorded against F. solani, while no inhibitory effect was observed against F. oxysporum and Colletotrichum coccodes.

Biogenic CuO and ZnO Nanoparticles as Nanofertilizers for Sustainable Growth of Amaranthus hybridus.

The biogenic synthesis of CuO and ZnO nanoparticles (NPs) was carried out by Stenotrophomonas maltophilia. The shape, size, and chemical identity of the CuO and ZnO NPs were determined using FTIR, XRD, SEM, EDX, and TEM analysis. The study aimed to investigate the effects of the CuO and ZnO NPs on Amaranthus hybridus seed germination and plant growth. Two different fertilizer application modes (hydroponics and foliar) were studied with varying concentrations of CuO (0.06 µM, 0.12 µM) and ZnO (0.12 µM, 0.24 µM) nanoparticles with water control and Hoagland's media control. The hydroponic system of fertilizer application demonstrated better efficiency in terms of plant growth as compared to the foliar application. The agronomic traits, SPAD value, total reducing sugars, antioxidant activity, amount of copper, and zinc ions in root and shoot were analyzed for all experimental plants and found better with the nanoparticle application. The highlight of the study is the application of extremely low concentrations of CuO and ZnO nanoparticles, almost 70% lower than the copper and zinc salts in the Hoagland's medium for improved plant growth. The use of lower concentrations of nanoparticles can prevent their accumulation in the environment and also lower the production cost. The high antioxidant concentration exhibited by the plants treated with CuO and ZnO nanoparticles ensures the enhanced plant's resistance to infections and pests while promoting plant growth.

Amaranthus hybridus (Amaranthaceae) prevents the detrimental effects of cyclophosphamide on ovarian function in Wistar rats: An experimental study.

Background: Cyclophosphamide (CP) is an anticancer agent, but its chronic administration induces ovarian toxicity. Objective: We evaluated the effects of aqueous extract (AE) and methanol extract (ME) of Amaranthus hybridus (A. hybridus) on CP-induced ovarian toxicity in rats. Materials and Methods: 40 female Wistar rats (10 wk, 170-200 gr) were distributed into 8 groups (n = 5/each) as follows: 1) healthy control; 2) CP+distilled water (10 ml/kg/d); 3) CP+3%-tween 80 (10 mL/kg/d); 4) CP+clomiphene citrate (2 mg/kg/d); 5, 6) CP+AE of A. hybridus (55 and 110 mg/kg/d); and 7, 8) CP+ME of A. hybridus (55 and 110 mg/kg/d). After 28 days of treatment, estrus cyclicity, ovarian and uterine weights as well as estradiol levels and ovarian histology were determined. Results: CP induced ovarian toxicity after 28 days of exposure. More specifically, CP disturbed the estrus cycle, decreased ovary and uterus weights (p = 0.04), and the 17-ß estradiol level (p = 0.04), and induced severe ovarian damages. Remarkably, A. hybridus significantly increased (p = 0.03) the ovarian weight (AE and ME at all doses) and uterus weight (ME at 110 mg/kg/d), compared with the CP-treated rats. Moreover, the 17-ß estradiol level was significantly elevated (p = 0.02) in rats given clomiphene citrate and A. hybridus (AE 110 mg/kg/d; ME 55 mg/kg/d). Finally, the ovaries of rats given plant extracts had many corpus luteum and normal follicles, and no cystic follicles. Conclusion: prevented the detrimental effects of CP on ovarian function, which could support its traditional use as a fertility enhancer.

Therapeutic Potential of Selected Medicinal Plant Extracts against Multi-Drug Resistant Salmonella enterica serovar Typhi.

Salmonella enterica serovar Typhi is Gram negative, rod shaped, facultative anaerobic bacterium, belongs to enterobacteriaceae family that causes typhoid fever in humans. This bacterium has become a super bug due to acquisition of multi drug resistance. Bacteria is transmitted through food and water contaminated with human feaces. Present study reports the screening of Adhatoda vasica, Amaranthus hybridus and Aloe barbadensis and their evaluation against multi-drug resistant Salmonella enterica serovar Typhi. Qualitative analysis of ten phytochemicals was conducted using chemical method and Gas Chromatography-Mass Spectrometry (GCMS). Antibacterial activity of plants was carried out by agar well diffusion method on Mueller Hinton agar. Total tannins, total alkaloids and total flavonoids of different parts of three plants were estimated through spectrophotometer. Total tannins content in different parts of plants was present in the given order Amaranthus hybridus leaf > Aloe barbadensis leaf > Adhatoda vasica leaf > Adhatoda vasica flower > Adhatoda vasica stem. Whereas, the order of total flavonoid concentration was Amaranthus hybridus leaf > Aloe barbadensis leaf > Adhatoda vasica leaf > Amaranthus hybridus seed. Total alkaloids have order, Adhatoda vasica leaf > Amaranthus hybridus leaf > Adhatoda vasica flower > Amaranthus hybridus seed > Aloe barbadensis leaf. Results of phytochemical analysis suggested that plants have strong profile of antioxidants, total phenolic contents and various enzymes proposing them best alternate to cure bacterial infections. GC-MS analysis further confirmed stronger phytochemical profile that can be utilized as antagonists to Salmonella enterica serovar Typhi.

The ameliorative potentials of aqueous leaf extract of Amaranthus hybridus on monosodium glutamate-induced testicular damage in Wistar rats.

OBJECTIVE: Amaranthus hybridus (AH) is a food plant commonly eaten in our country known as a good source of vitamins, minerals, and antioxidants. The present study was designed to investigate the ameliorative potentials of aqueous extract of A. hybridus on Monosodium Glutamate (MSG) -induced testicular toxicity in adult Wistar rats. METHODS: Thirty-two male Wistar rats weighing 160-180 g were divided into four groups. Group A served as control; rats in Group B were given 300 mg/kg of body weight (BW) of aqueous leaf extract of AH; rats in Group C were given 4 mg/g (BW) of 40% MSG; and rats in Group D were given 4 mg/g (BW) of 40% MSG and 300 mg/kg (BW) of extract orally for 6 weeks. RESULTS: There was a significant increase in body weight and a significant reduction in testis weight, testis volume, and testis/body weight ratio in the group given only MSG when compared with controls. Histologically, rats in Groups A and B had normal testicular architecture, while the rats given MSG only showed a significant derangement in testicular histoarchitecture and impaired sperm parameters when compared with controls and the rats given AH. However, these derangements were alleviated in the MSG+AH group when compared with controls. CONCLUSIONS: Aqueous leaf extract of AH ameliorated the testicular derangement resulting from MSG administration.

New Mutant Amaranth Varieties as a Potential Source of Biologically Active Substances.

Amaranth species represent a diverse group of plants. Many of them are a rich source of secondary metabolites with many positive biological effects. Total phenolic, total flavonoid and rutin content, antioxidant activity against superoxide and hydroxyl radicals, FRAP (Ferric-reducing ability of plasma) assay and DPPH (2,2-Diphenyl-1-picrylhydrazyl) radical scavenging assay were determined in ethanol extracts of dried leaves of the new Slovak amaranth varieties 'Pribina' and 'Zobor'. The amount of total phenolic substances ('Pribina' GAE 38.3 mg.g-1 DM and 'Zobor' GAE 26.1 mg.g-1 DM), content of total flavonoids ('Pribina' QE 26.5 mg.g-1 DM and 'Zobor' QE 20.3 mg.g-1 DM) and rutin ('Pribina' 50.8 mg.g-1 DM and 'Zobor' 15.2 mg.g-1 DM) were higher in the variety 'Pribina', compared to the variety 'Zobor'. A statistically higher antioxidant activity against superoxide radical (1.63%·mg-1g-1 DM), hydroxyl radical (3.20%.mg-1g-1 DM), FRAP assay (292.80 µmol.L-1·mg-1.g-1 DM) and DPPH (54.2 ± 1.78 µg.mL-1 DM) were detected in the 'Pribina' variety. Antiradical and antioxidant activities of both extracts showed high positive correlations in relation to the content of total phenolic substances, total flavonoids and rutin. Amaranth is an undemanding crop on specific environmental conditions and is resistant to abiotic and biotic stress.

Amino acid profiles of Solanum aethiopicum, Amaranthus hybridus, and Telfairia occidentalis, common leafy vegetables in Nigeria.

The aim was to evaluate the amino acid compositions of three commonly consumed leafy vegetables (Solanum aethiopicum, Amaranthus hybridus, and Telfairia occidentalis) in Abakaliki, Ebonyi State. Leafy vegetables are important protective foods and beneficial for the maintenance of healthy living and prevention of diseases. The fresh leaves of A. hybridus, T. occidentalis, and S. aethiopicum were air-dried under room temperature for 1 week. The dried samples were further milled into a fine powder using a mechanical grinder and were stored in an air-tight plastic container. Amino acid content was determined using an applied Bio-system (phenylthiohydantoin, PTH) amino acid analyzer. Among amino acids determined in the vegetables, glutamic acid had the highest value with 12.59, 11.20, and 11.96 g/100 g protein, which was followed closely by leucine with 9.81, 7.94, 9.28 g/100 g protein, and aspartic acid with 8.99, 8.62, and 9.74 g/100 g protein in S. aethiopicum, A. hybridus, and T. occidentalis, respectively on dry weight bases. The leaf that contained the highest total amino acid (TAA) was S. aethiopicum with 88.69 g/100 g protein followed by T. occidentalis with 80.39 g/100 g protein while A. hybridus being the lowest, had 73.38 g/100 g protein. The limiting essential amino acid was tryptophan with 1.98 g/100 g protein while leucine with 9.0 g/100 g protein was the most abundant TAA. The percentage concentration of different groups of amino acid in vegetables revealed that total essential amino acid (TEAA) had 54.85%, total non-essential amino acid (TNEAA) had 48.27%, total neutral amino acid (TNAA) had 22.24%, total acidic amino acid (TAAA) had 32.48%, total basic amino acid (TBAA) had 11.53%, total aromatic amino acid (TArAA) had 11.89% while total sulfur amino acid (TSAA) had 3.94%. The results indicate that the vegetables studied are rich in essential amino acids and could serve as a good source of quality protein. Therefore, they could be recommended as food supplements, especially when animal proteins become more expensive as a source of protein.

Optimization of timing of next-generation emergence in Amaranthus hybridus is determined via modulation of seed dormancy by the maternal environment.

The timing of emergence of weed species has critical ecological and agronomical implications. In several species, emergence patterns largely depend on the level of dormancy of the seedbank, which is modulated by specific environmental factors. In addition, environmental conditions during seed maturation on the mother plant can have marked effects on the dormancy level at the time of seed dispersal. Hence, the maternal environment has been suggested to affect seedbank dormancy dynamics and subsequent emergence; however, this modulation has not been adequately examined under field conditions, and the mechanisms involved are only partly understood. Combining laboratory and field experiments with population-based models, we investigated how dormancy level and emergence in the field are affected by the sowing date and photoperiod experienced by the mother plant in Amaranthus hybridus, a troublesome weed worldwide. The results showed that an earlier sowing date and a longer photoperiod enhanced the level of dormancy by increasing the dormancy imposed by both the embryo and the seed coat. However, this did not affect the timing and extent of emergence in the field; on the contrary, the variations in dormancy level contributed to synchronizing the emergence of the next generation of plants with the time period that maximized population fitness. Our results largely correspond with effects previously observed in other species such as Polygonum aviculare and Arabidopsis, suggesting a common effect exists within different species.

Three new methods indicate that CO2 concentration affects plant respiration in the range relevant to global change.

Short-term responses of plant dark respiration to carbon dioxide concentration ([CO2]) in the range anticipated in the atmosphere with global change remain controversial, primarily because it is difficult to convincingly eliminate the many possible sources of experimental error in measurements of carbon dioxide or oxygen exchange rates. Plant dark respiration is a major component of the carbon balance of many ecosystems. In seedlings without senescent tissue, the rate of loss of dry mass during darkness indicates the rate of respiration. This method of measuring respiration was used to test for [CO2] effects on respiration in seedlings of three species with relatively large seeds. The time it took respiration to exhaust substrates and cause seedling death in darkness was used as an indicator of respiration rate in four other species with smaller seeds. The third method was measuring rates of CO2 exchange in excised petioles sealed in a cuvette submerged in water to prevent leaks. Petioles were utilized as the plant tissue type with the most reliable rates of respiration, for excised tissue. The rate of loss of dry mass in the dark decreased with increasing [CO2] in the range of 200-800 µmol mol-1 in all three large-seeded species. The seedling survival time in the dark increased with [CO2] in the same concentration range in all four of the smaller-seeded species. Respiration rates of excised petioles of several species also decreased over this [CO2] range. The data provide new evidence that the rate of dark respiration in plant tissue often decreases with increasing [CO2] in the 200-800 µmol mol-1 range.

Purification, characterization and antioxidant activities in vitro of polysaccharides from Amaranthus hybridus L.

BACKGROUND: Amaranthus hybridus L. is an annual, erect or less commonly ascending herb that is a member of the Amaranthaceae family. Polysaccharides extracted from traditional Chinese medicines may be effective substances with antioxidant activity. METHODS: In this study, we isolated crude polysaccharides from A. hybridus (AHP-M) using microwave-assisted extraction. Then, the AHP-M was purified by chromatography with DEAE-32 cellulose, and two fractions, AHP-M-1 and AHP-M-2, were obtained. The structural characteristics of AHP-M-1 and AHP-M-2 were investigated, and their antioxidant activities were analyzed in vitro. RESULTS: We found that the monosaccharide composition of AHP-M-1 was different from that of AHP-M-2. The molecular weights of AHP-M-1 and AHP-M-2 were 77.625 kDa and 93.325 kDa, respectively. The results showed that the antioxidant activity of AHP-M-2 was better than that of AHP-M-1. For AHP-M-2, the DPPH radical scavenging rate at a concentration of 2 mg/mL was 78.87%, the hydroxyl radical scavenging rate was 39.34%, the superoxide anion radical scavenging rate was 80.2%, and the reduction ability of Fe3+ was approximately 0.90. The total antioxidant capacity per milligram of AHP-M-2 was 6.42, which was higher than that of Vitamin C (Vc). CONCLUSION: The in vitro test indicated that AHP-M-1 and AHP-M-2 have good antioxidant activity, demonstrating that A. hybridus L. polysaccharide has immense potential as a natural antioxidants.

Agrobacterium rhizogenes-mediated transformation of grain (Amaranthus hypochondriacus) and leafy (A. hybridus) amaranths.

KEY MESSAGE: Transgenic A. hypochondriacus and A. hybridus roots were generated. Further, a distinct plant regeneration program via somatic embryos produced from hairy roots was established. Work was implemented to develop an optimized protocol for root genetic transformation of the three grain amaranth species and A. hybridus, their presumed ancestor. Transformation efficiency was species-specific, being higher in A. hypochondriacus and followed by A. hybridus. Amaranthus cruentus and A. caudatus remained recalcitrant. A reliable and efficient Agrobacteruim rhizogenes-mediated transformation of these species was established using cotyledon explants infected with the previously untested BVG strain. Optimal OD600 bacterial cell densities were 0.4 and 0.8 for A. hypochondriacus and A. hybridus, respectively. Hairy roots of both amaranth species were validated by the amplification of appropriate marker genes and, when pertinent, by monitoring green fluorescent protein emission or ß-glucuronidase activity. Embryogenic calli were generated from A. hypochondriacus rhizoclones. Subsequent somatic embryo maturation and germination required the activation of cytokinin signaling, osmotic stress, red light, and calcium incorporation. A crucial step to ensure the differentiation of germinating somatic embryos into plantlets was their individualization and subcultivation in 5/5 media containing 5% sucrose, 5 g/L gelrite, and 0.2 mg/L 2-isopentenyladenine (2iP) previously acidified to pH 4.0 with phosphoric acid, followed by their transfer to 5/5 + 2iP media supplemented with 100 mg/L CaCl2. These steps were strictly red light dependent. This process represents a viable protocol for plant regeneration via somatic embryo germination from grain amaranth transgenic hairy roots. Its capacity to overcome the recalcitrance to genetic transformation characteristic of grain amaranth has the potential to significantly advance the knowledge of several unresolved biological aspects of grain amaranths.

Extraction of polysaccharides from Amaranthus hybridus L. by hot water and analysis of their antioxidant activity.

BACKGROUND: Amaranthus hybridus L. is an annual herb that belongs to the Amaranthceae family, a type of multi-purpose grain, vegetable and feed crop that has received considerable attention due to its great economic value. However, the composition of polysaccharides from A. hybridus has rarely been previously reported. METHODS: In this study, the aboveground part of A. hybridus was used as material and polysaccharides were isolated by the hot water extraction method. Two acidic polysaccharides were isolated and purified by the Sevage method and diethylaminoethyl cellulose-32 column chromatography. RESULTS: Two acidic polysaccharides were obtained from A. hybridus: AHP-H-1 and AHP-H-2. There were significant differences between the monosaccharide content from each sample according to gas chromatography-mass spectrometer. AHP-H-2 had higher antioxidant activity in vitro than AHP-H-1. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging rate of two mg/mL AHP-H-2 was 80%, its hydroxyl radical scavenging rate was approximately 48.5%, its superoxide anion radical scavenging rate was 85.3% and its reduction ability of Fe3+ was approximately 0.92. The total antioxidant capacity of each milligram of AHP-H-2 was 6.5, which was higher than ascorbic acid. CONCLUSION: The results of the study promote the effective use of A. hybridus and provide a theoretical basis for its development.

Effects of plant growth regulators (DA-6 and 6-BA) and EDDS chelator on phytoextraction and detoxification of cadmium by Amaranthus hybridus Linn.

In this study, pot experiments were carried out to investigative the effects of growth-promoting hormone diethyl aminoethyl hexanoate (DA-6), 6-Benzylaminopurine (6-BA), and chelator [S,S]-Ethylenediaminedisuccinic acid (EDDS) when applied to soil contaminated with cadmium (Cd). The substances were applied alone and in combination to assess their impact on biomass, Cd phytoextraction, subcellular distribution, and chemical forms in Cd hyperaccumulator Amaranthus hybridus Linn. (A. hybridus). Results showed that the treatment of EDDS alone inhibited plant growth, and raised the Cd concentration in the plant shoot and root. Treatments with DA-6 and 6-BA combined with EDDS alleviated the negative effect of EDDS on plant growth, resulting in a synergistic effect on Cd phytoaccumulation and translocation. At the subcellular level, DA-6 and 6-BA detoxified the Cd toxicity in the plant by retaining the Cd in the cell wall. On the distribution of the chemical form of Cd in plant shoot, DA-6 and 6-BA significantly decreased Cd mobility in the plant compared to EDDS. These results confirmed that combining DA-6 and 6-BA with EDDS can counteract the adverse effect of EDDS on plant growth. The treatment of 5.0 mmol kg-1 EDDS + 1 µM DA-6 was optimal for improving the remediation of A. hybridus Linn. growing in Cd contaminated soil.

Cytogenetic characterization of Amaranthus caudatus L. and Amaranthus hybridus subsp. cruentus (L.) Thell.

The present study is aimed to identify genetic variability between two species of Amaranthus viz., A. caudatus and A. hybridus subsp. cruentus, two economically important species, cultivated mainly for grain production. Karyomorphological studies in Amaranthus are scarce, probably due to higher number of small sized chromosomes. Karyomorphological studies were conducted using mitotic squash preparation of young healthy root tips. Karyological parameters and karyotypic formula were established using various software programs and tabulated the karyomorphometric and asymmetry indices viz., Disparity index, Variation coefficient, Total forma percentage, Karyotype asymmetry index, Syi index, Rec index, Interchromosomal and Intrachromosomal asymmetry index and Degree of asymmetry of karyotypes. The mitotic chromosome number observed for A. caudatus was 2n = 32 with a gametic number n = 16 and A. hybridus subsp. cruentus was 2n = 34 with a gametic number n = 17. In A. caudatus the chromosome length during somatic metaphase ranged from 0.8698 to 1.7722 µm with a total length of 39.1412 µm. In A. hybridus subsp. cruentus the length of chromosome ranged from 0.7756 to 1.9421 µm with a total length of 44.9922 µm. Various karyomorphometry and asymmetry indices analyzed revealed the extend of interspecific variation and their evolutionary status.

Effect of drying and cooking on nutritional value and antioxidant capacity of morogo (Amaranthus hybridus) a traditional leafy vegetable grown in South Africa.

Morogo (vegetables in Tswana) is a green leafy vegetable from the Amaranthaceae family that can be harvested from wild growing or cultivated. The objective of this study was to determine the nutritional value, the total antioxidant capacity and selected bioactive compounds present in morogo leaves, and evaluate the effect of drying and cooking. Results showed that morogo contained a significant amount of protein (3.6 ± 0.1 g/100 g FW) and minerals which the level exceed 1% of fresh weight. The total antioxidant capacity (µmole TE/ 100 g FW) determined by DPPH and FRAP assays were 118.3 ± 15.3 and 128.4 ± 11.9 respectively. Total polyphenols (109.4 ± 7.5 mg GAE/100 g FW), vitamin C (36.6 ± 1.0 mg /100 g FW) and carotenoids represented by ß carotene (25.3 ± 1.3 mg /100 g FW) and xanthophylls (7.48 ± 0.31 mg /100 g FW) formed a significant part of bioactive compounds content of morogo leaves. Since the boiling can cause significant losses of compounds in the boiling water, it can be recommended to avoid cooking methods that can include a boiling step with discard of boiling water.

Modulatory of effect of fresh Amaranthus caudatus and Amaranthus hybridus aqueous leaf extracts on detoxify enzymes and micronuclei formation after exposure to sodium arsenite.

Vegetables are the cheapest and most available sources of important proteins, minerals, vitamins, and essential amino protein. These vegetables are commonly used in Africa for the treatment of illness. This study evaluated the protective effects of Amaranthus caudatus and A. hybridus against sodium arsenite-induced toxicity in rats. The effects of sodium arsenite and/or the plant extracts were assessed using bone marrow micronucleus assay and by measuring the activities of tumour maker enzymes such as gamma glutamyl transferase (GGT) and alkaline phosphatase (ALP) in white albino Wister rats. The study showed that sodium arsenite significantly (P < 0.05) induced the formation of micronucleated polychromatic erythrocytes and the activities of ALP and GGT when compared with control. The levels of white blood cell, hemoglobin, and lymphocyte count were altered in sodium arsenite fed rats and were reverted back to near normal levels in rats pretreated with the plant extracts. A. caudatus and A. hybridus showed significant role in protecting the detoxifying enzymes; also, A. caudatus has a more protective effect on reducing the micronuclei formation when compared with A. hybridus. This study suggests that A. caudatus and A. hybridus possess anticarcinogenic effect.

Intoxicação espontânea por Amaranthus hybridus (Amaranthaceae) em bovinos no sul do Rio Grande do Sul / Spontaneous poisoning by Amaranthus hybridus in cattle in southern Rio Grande do Sul

Descreve-se um surto de intoxicação por Amaranthus hybridus ocorrido em bovinos em fevereiro/março de 2013 na região sul do Rio Grande do Sul. A morbidade foi de 48,33%, a mortalidade de 41,66% e a letalidade 86,20%. O diagnóstico da intoxicação por A. hybridus foi baseado nos dados epidemiológicos, sinais clínicos, achados de necropsia e lesões histológicas características da intoxicação por plantas nefrotóxicas e pela presença da planta em grande quantidade na área onde estavam os bovinos. A invasão da pastagem de Brachiaria sp. pela planta alerta para a possibilidade da ocorrência da intoxicação não somente em áreas de resteva com carência de forragem, uma vez que no surto relatado neste trabalho havia abundante disponibilidade de forragem nas áreas onde os bovinos se intoxicaram. No presente caso provavelmente as boas condições climáticas e o solo fertilizado para a plantação da pastagem favoreceram o crescimento da invasora.

An outbreak of Amaranthus hybridus poisoning in cattle was observed in February/March 2013 in southern Rio Grande do Sul, Brazil. The morbidity rate observed was 48.33%, the mortality rate was 41.66% and lethality rate was 86.20%. The diagnosis of A. hybridus poisoning was made based on the epidemiological data, clinical signs, macroscopic and histological lesions characteristic of intoxication by nephrotoxic plants and by the presence of large amounts of the plant in the area where cattle were placed. Invasion of Brachiaria sp. pasture by A. hybridus alerts for the possibility of the occurrence of poisoning not only in stubble areas with lack of forage. In the case reported here there was abundant forage availability in the area where the outbreak occurred. Favorable climatic conditions and fertile soil for planting pasture, probably favored the growth of this invasive species.

Primeiro registro de Aphis craccivora Koch 1854 (Hemiptera: Aphididae) sobre plantas daninhas em Santa Maria, RS / First record of Aphis craccivora Koch 1854 (Hemiptera: Aphididae) on weed in Santa Maria, RS State

Aphis craccivora Koch (Hemiptera: Aphididae) é um afídeo-praga que ocorre em diferentes cultivos e causa danos relacionados ao hábito da sucção de seiva. No Brasil, são raros os registros de plantas daninhas hospedeiras dessa espécie, particularmente no Estado do Rio Grande do Sul (RS). Plantas daninhas infestadas com afídeos foram encontradas em área experimental localizada no campus da Universidade Federal de Santa Maria (UFSM), RS, em duas datas, 22/02/2010 e 25/03/2010. No segundo registro (25/03/2010), cada planta daninha foi medida e avaliada quanto ao número de afídeos. A espécie foi identificada como Aphis craccivora e as plantas daninhas hospedeiras, como Amaranthus hybridus Linnaeus, 1753 (Amaranthaceae), caruru-roxo, e Solanum americanum Mill, 1768 (Solanaceae), maria-pretinha. Este trabalho faz o primeiro registro de A. hybridus e S. americanum hospedando A. craccivora em Santa Maria, no Rio Grande do Sul.

Aphis craccivora Koch (Hemiptera: Aphididae) is an aphid pest which occurs in different crops and causes damages related to habit of sucking sap. In Brazil information about host weed species are rare, particulary in Rio Grande do Sul (RS) State. Weeds infested by aphids were found at an experimental area located at the Universidade Federal de Santa Maria, Santa Maria, RS, in two different dates, February 22nd and March 25th 2010. In the second record (March 25th), each weed plant was measured and evaluated on the number of aphids. The aphid species was identified as Aphis craccivora and the host weed as Amaranthus hybridus Linnaeus, 1753 (Amaranthaceae), and Solanum americanum Mill, 1768 (Solanaceae). This is the first report of both A. hybridus and S. americanum hosting A. craccivora in Santa Maria, Rio Grande do Sul State.

Host Status of Five Weed Species and Their Effects on Pratylenchus zeae Infestation of Maize.

The host suitability of five of the most common weed species occurring in maize (Zea mays L.) fields in South Africa to Pratylenchus zeae was tested. Based on the number of nematodes per root unit, mealie crotalaria (Crotalaria sphaerocarpa) was a good host; goose grass (Eleusine indica), common pigweed (Amaranthus hybridus), and thorn apple (Datura stramonium) were moderate hosts; and khaki weed (Tagetes minuta) was a poor host. Only the root residues of khaki weed suppressed the P. zeae infestation of subsequently grown maize. When goose grass, khaki weed, and mealie crotalaria were grown in association with maize in soil infested with P. zeae, goose grass and khaki weed severely suppressed maize root development; this resulted in a low number of nematodes per maize root system and a high number of nematodes per maize root unit. Mealie crotalaria did not restrict maize root growth and did not affect nematode densities per maize root system or maize root unit. Special attention should be given to the control of mealie crotalaria, which is a good host for P. zeae, and goose grass, which, in addition to its ability to compete with maize, is also a suitable host for P. zeae.