Green synthesis of silver nanoparticles using Citrus limon peels and evaluation of their antibacterial and cytotoxic properties

The present work aimed to synthesis silver nanoparticles (AgNPs) using biological waste products Citrus limon peels, its characterization, antimicrobial activities and the cytotoxic effect of the synthesized green AgNPs. Characterization of the prepared AgNPs showed the formation of spherical, and few agglomerated AgNPs forms as measured by UV–visible spectrophotometer. The average size of the prepared AgNPs was 59.74 nm as measured by DLS technique. The spectrum of the synthesized AgNPs was observed at 3 KeV using the EDX. On the other hand, FTIR analysis of the green synthesized AgNPs showed the presence of alcohols, phenolics, mono-substituted alkynes, aliphatic primary amines, sodium salt, amino acid, or SiOH alcohol groups. The antimicrobial studies of the formed AgNPs showed positive activity against most of the studied human pathogenic bacteria with varying degrees. Finally, the evaluation of the cytotoxic effect of the green synthesized AgNPs were done using two types of cell lines, human breast cancer cell line (MCF-7) and human colon carcinoma cell line (HCT-116). The results revealed the concentration has a direct correlation with cell viability. The 50% inhibitory concentration (IC₅₀) of MCF-7 cell line was in of 23.5 ± 0.97 µL/100 µL, whereas the HCT-116 cell line was in 37.48 ± 5.93 µL/100 µL.     

Green synthesis and characterization of gold nanoparticles using endophytic fungi Fusarium solani and its in-vitro anticancer and biomedical applications

The present study aimed to explore the anticancer potentials of the gold nanoparticles (NPs) obtained by green synthesis method using an endophytic strain Fusarium solani ATLOY – 8 has been isolated from the plant Chonemorpha fragrans. The formation of the NPs was analyzed by UV, FTIR, SEM and XRD. The synthesized NPs showed pink-ruby red colors and high peak plasmon band was observed between 510 and 560 nm. It is observed that intensity of absorption steadily increases the wavelength and band stabilizes at 551 nm. The XRD pattern revealed the angles at 19, 38.32, 46.16, 57.50, and 76.81° respectively. Interestingly, the FTIR band absorption noted at 1413 cm⁻¹, 1041 cm⁻¹ and 690 cm⁻¹ ascribed the presence of amine II bands of protein, C-N and C-H stretching vibrations of the nanoparticles. SEM analysis indicated that the average diameter of the synthesized nanoparticles was between 40 and 45 nm. These NPs showed cytotoxicity on cervical cancer cells (He La) and against human breast cancer cells (MCF-7) and the NPs exhibited dose dependent cytotoxic effect. IC50 value was 0.8 ± 0.5 μg/mL on MCF-7 cell line and was found to be 1.3 ± 0.5 μg/mL on MCF-7 cell lines. The synthesized NPs induced apoptosis on these cancer cell lines. The accumulation of apoptotic cells decreased in sub G0 and G1 phase of cell cycle in the MCF-7 cancer cells were found to be 55.13%, 52.11% and 51.10% after 12 h exposure to different concentrations. The results altogether provide an apparent and versatile biomedical application for safer chemotherapeutic agent with little systemic toxicity.     

Instant green synthesis of silver nanoparticles using Terminalia chebula fruit extract and evaluation of their catalytic activity on reduction of methylene blue

A novel green approach for the synthesis and stabilization of silver nanoparticles (AgNPs) using water extract of Terminalia chebula (T. chebula) fruit under ambient conditions is reported in this article. The instant formation of AgNPs was analyzed by visual observation and UV–visible spectrophotometer. Further the effect of pH on the formation of AgNPs was also studied. The synthesized AgNPs were characterized by FT-IR, XRD, HR-TEM with EDS and DLS with zeta potential. Appearance of brownish yellow color confirmed the formation of AgNPs. In the neutral pH, the stability of AgNPs was found to be high. The stability of AgNPs is due to the high negative values of zeta potential and capping of phytoconstituents present in the T. chebula fruit extract which is evident from zeta potential and FT-IR studies. The XRD and EDS pattern of synthesized AgNPs showed their crystalline structure, with face centered cubic geometry oriented in (1 1 1) plane. HR-TEM and DLS studies revealed that the diameter of stable AgNPs was approximately 25 nm. Moreover the catalytic activity of synthesized AgNPs in the reduction of methylene blue was studied by UV–visible spectrophotometer. The synthesized AgNPs are observed to have a good catalytic activity on the reduction of methylene blue by T. chebula which is confirmed by the decrease in absorbance maximum values of methylene blue with respect to time using UV–visible spectrophotometer and is attributed to the electron relay effect.     

Biogenic synthesis of multifunctional silver nanoparticles from <Emphasis Type="Italic">Rhodotorula glutinis</Emphasis> and <Emphasis Type="Italic">Rhodotorula mucilaginosa</Emphasis>: antifungal,catalytic and cytotoxicity activities

Silver nanoparticles (AgNPs) have several technological applications and may be synthetized by chemical, physical and biological methods. Biosynthesis using fungi has a wide enzymatic range and it is easy to handle. However, there are few reports of yeasts with biosynthetic ability to produce stable AgNPs. The purpose of this study was to isolate and identify soil yeasts (Rhodotorula glutinis and Rhodotorula mucilaginosa). After this step, the yeasts were used to obtain AgNPs with catalytic and antifungal activity evaluation. Silver Nanoparticles were characterized by UV–Vis, DLS, FTIR, XRD, EDX, SEM, TEM and AFM. The AgNPs produced by R. glutinis and R. mucilaginosa have 15.45?±?7.94 nm and 13.70?±?8.21 nm (average?±?SD), respectively, when analyzed by TEM. AgNPs showed high catalytic capacity in the degradation of 4-nitrophenol and methylene blue. In addition, AgNPs showed high antifungal activity against Candida parapsilosis and increase the activity of fluconazole (42.2% for R. glutinis and 29.7% for R. mucilaginosa), while the cytotoxicity of AgNPs was only observed at high concentrations. Finally, two yeasts with the ability to produce AgNPs were described and these particles showed multifunctionality and can represent a technological alternative in many different areas with potential applications.     

The immunomodulation of inducible nitric oxide in scallop Chlamys farreri

Nitric oxide (NO) is an important signalling molecule which plays an indispensable role in immunity of all vertebrates and invertebrates. In the present study, the immunomodulation of inducible NO in scallop Chlamys farreri was examined by monitoring the alterations of haemocyte behaviours and related immune molecules in response to the stimulations of LPS and/or with S-Methylisothiourea Sulphate (SMT), an inhibitor of inducible NO synthase (NOS). The total activity of NOS and NO concentration in the haemolymph of scallop C. farreri increased significantly at 3, 6 and 12 h after LPS stimulation respectively, whereas their increases were fully repressed when scallops were treated in the collaborating of LPS and SMT. Meanwhile, some cellular and humoral immune parameters were determined after the stimulation of LPS and SMT to investigate the role of inducible NO in innate immunity of scallop. After LPS stimulation, the highest levels of haemocytes apoptosis and phagocytosis were observed at 24 h (38.5 ± 2.5%, P < 0.01) and 12 h (38.6 ± 0.2%, P < 0.01), respectively, and the reactive oxygen species (ROS) level (5.88 ± 0.90%, P < 0.01) of haemocytes and anti-bacterial activity of haemolymph (10.0 ± 2.2%, P < 0.01) all elevated dramatically at 12 h. Although the activity of lysozyme and phenoloxidase (PO) in haemolymph both declined at 48 h (93.0 ± 6.3 U mgprot^?1, 0.40 ± 0.06 U mgprot^?1, P < 0.01), superoxide dismutase (SOD) activity and GSH concentration both increased to the highest level at 24 h post treatment (99.2 ± 8.1 U mgprot^?1, 93.0 ± 6.3 nmol mgprot^?1, P < 0.01). After the collaborating treatment of LPS and SMT, the apoptosis index increased much higher from 48 h, while the increase of haemocytes phagocytosis, ROS level and haemolymph anti-bacteria activities were suppressed completely at 12 h. The declines of lysozyme and PO activity in haemolymph were reversed at 48 h, and the rise of SOD activity and GSH concentration started earlier from 3 h. These results indicated clearly that NO could participate in the scallop immunity and play a crucial role in the modulation of immune response including haemocytes apoptosis and phagocytosis, anti-bacterial activity and redox homeostasis in the haemolymph of scallop.     

Identification of a marine NADPH-dependent aldehyde reductase for chemoselective reduction of aldehydes

A putative aldehyde reductase gene from Oceanospirillum sp. MED92 was overexpressed in Escherichia coli. The recombinant protein (OsAR) was characterized as a monomeric NADPH-dependent aldehyde reductase. The kinetic parameters K_m and k_cat of OsAR were 0.89 ± 0.08 mM and 11.07 ± 0.99 s⁻¹ for benzaldehyde, 0.04 ± 0.01 mM and 6.05 ± 1.56 s⁻¹ for NADPH, respectively. This enzyme exhibited high activity toward a variety of aromatic and aliphatic aldehydes, but no activity toward ketones. As such, it catalyzed the chemoselective reduction of aldehydes in the presence of ketones, as demonstrated by the reduction of 4-acetylbenzaldehyde or the mixture of hexanal and 2-nonanone, showing the application potential of this marine enzyme in such selective reduction of synthetic importance.     

Biogenic synthesis of silver nanoparticles: Antibacterial and cytotoxic potential

In green chemistry, the application of a biogenic material as a mediator in nanoparticles formation is an innovative nanotechnology. Our current investigation aimed at testing the cytotoxic potential and antimicrobial ability of silver nanoparticles (AgNPs) that were prepared using Calligonum comosum roots and Azadirachta indica leaf extracts as stabilizing and reducing agents. An agar well diffusion technique was employed to detect synthesized AgNPs antibacterial ability on Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus bacterial strains. Furthermore, their cytotoxic capability against LoVo, MDA-MB231 and HepG2 ca cells was investigated. For phyto-chemical detection in the biogenic AgNPs the Fourier-transform infrared spectroscopy (FT-IR) was considered. Zeta sizer, TEM (Transmission Electron Microscope) and FE-SEM (Field Emission Scanning Electron Microscope) were used to detect biogenic AgNPs’ size and morphology. The current results showed the capability of tested plant extract for conversion of Ag ions to AgNPs with a mean size ranging between 90.8 ± 0.8 and 183.2 ± 0.7 nm in diameter. Furthermore, prepared AgNPs exhibited apoptotic potential against HepG2, LoVo, and MDA-MB 231cell with IC₅₀ ranging between 10.9 and 21.4 μg/ml and antibacterial ability in the range of 16.0 ± 0.1 to 22.0 ± 1.8 mm diameter. Activation of caspases in AgNPs treated cells could be the main indicator for their positive effect causing apoptosis. The current investigation suggested that the green production of AgNPs could be a suitable substitute to large-scale production of AgNPs, since stable and active nanoparticles could be obtained.     

Evaluation of analgesic,antiamnesic and antidiarrheal potentials of Medicago denticulata extract using animal model

The analgesic, antidiarrheal, and neuro-pharmacological potentials of Medicago denticulata leaves extract were screened in animal models. Potential analgesic response was noted (*P < 0.05, ^**P < 0.01, ^***P < 0.001) in formalin, acetic acid and heat-induced pain models in a dose-dependent manner. Maximum activity by means of writhing inhibition was documented for Medicago denticulata at 300 mg/kg that was found to be 71.79% (17.43 ± 1.31). In first phase, the Medicago denticulata at a dose of 150 and 300 mg/kg showed analgesic activity and reduced the pain by 54.18% (18.39 ± 1.67) and 62.90% (14.89 ± 1.56), respectively. In second phase, the Medicago denticulata at a dose of 150 and 300 mg/kg showed analgesic activity and reduced the pain by 69.48% (19.78 ± 1.44) and 70.89% (18.86 ± 1.58), respectively. In hot plate method, the Medicago denticulata at a dose of 150 and 300 mg/kg showed the maximum response of 61.16% (8.47 ± 1.23) and 67.39% (10.09 ± 1.04), respectively at 60 min. Scopolamine significantly reduces spontaneous alteration in Y-maze model for antiamnesic activity. Medicago denticulata significantly increased the discrimination index in a dose-dependent manner using novel object recognition test (NORT) model. Exploration time in sec for the novel object was increased significantly (P < 0.001) by donepezil decreased for familiar one with a discrimination index (DI) of 62.18%. Medicago denticulata significantly increased the discrimination index by 60.86% and 57.24% at 300 and 150 mg/kg b.w, respectively. The lowest DI of 53.80% at 75 mg/kg was observed in comparison to the amnesic group. The Medicago denticulata significant decreased the elevated levels of acetylcholinesterase (AChE) and malondialdehyde (MDA and enhancing level of acetylcholine (ACh), superoxide dismutase (SOD) and catalase (CAT) acting as an antioxidant agent. Medicago denticulata reduced the total number of diarrheal feces to lesser extent at dose-dependent manner. From the study results, it is suggested that the Medicago denticulata extract possess good analgesic and antiamnesic activity however the antidiarrheal effects of plant were negligible. In the current study, the traditional use of the plant as a source of medicine has been validated.     

Anti-depressive-like effect of monoterpene trans-anethole via monoaminergic pathways

Trans-anethole (ANE) is a monoterpene present in many aromatic plants, especially Pimpinella anisum (PA). In this regard, we previously reported the anti-depressant potential of PA. Here, we examined the anti-depressant activity of ANE and its possible mechanism in mice. In experiment 1, the animals received ANE (12.5–50 mg.kg ^-1) 60 min prior to forced swimming and open-field tests. In experiment 2, the animals received several receptor antagonists to assess the possible mechanism of ANE. The administration of ANE (25 and 50 mg.kg ^-1; p < 0.01 and p < 0.001, respectively) exhibited an anti-depressive-like effect in FST without any significant effect on animal locomotion(p > 0.05). Moreover, haloperidol(p < 0.001), SCH23390(p < 0.001), sulpiride(p < 0.001), ketanserin(p < 0.001), p-chlorophenylalanine(p < 0.001), WAY100135(p < 0.001), reserpine, (p < 0.001) prazosin(p < 0.001), and yohimbine(p < 0.001) inhibited the anti-depressive-like effect of ANE. Furthermore, co-treatment of a subeffective dose of ANE with imipramine or fluoxetine induced synergistic anti-depressant-like effects(p < 0.001). Our data mainly showed that the anti-depressive-like effect of ANE, which can be attributed to the contribution of the monoaminergic system.     

Comparative study of antifungal activity of two preparations of green silver nanoparticles from Portulaca oleracea extract

The green silver nanoparticles (green AgNPs) exhibit an exceptional antimicrobial property against different microbes, including bacteria and fungi. The current study aimed to compare the antifungal activities of both the crude aqueous extract of Portulaca oleracea or different preparations of green AgNPs biosynthesized by mixing that aqueous extract with silver nitrate (AgNO₃). Two preparations of the green AgNPs were synthesized either by mixing the aqueous extract of P. oleracea with silver nitrate (AgNO₃) (normal AgNPs) or either irradiation of the AgNPs, previously prepared, under ⁶⁰Co γ-ray using chitosan (gamma-irradiated AgNPs). Characterization of different AgNPs were tested by Zeta potential analyzer, Ultraviolet (UV) Visible Spectroscopy, and Fourier-Transform Infrared (FTIR) spectrometry. Three different plant pathogenic fungi were tested, Curvularia spicifera, Macrophomina phaseolina, and Bipolaris sp. The antifungal activities were evaluated by Transmission Electron Microscope (TEM) for either the crude aqueous extract of P. oleracea at three doses (25%, 50%, and 100%) or the newly biosynthesized AgNPs, normal or gamma-irradiated. With a few exceptions, the comparative analysis revealed that the irradiated green AgNPs at all three concentrations showed a relatively stronger antifungal effect than the normal AgNPs against all the three selected fungal strains. UV–visible spectroscopy of both preparations showed surface plasmon resonance at 421 nm. TEM results showed that both AgNPs were aggregated and characterized by a unique spherical shape, however, the gamma-irradiated AgNPs were smaller than the non-irradiated AgNPs (0.007–0.026 µM vs. 0.009–0.086 µM). TEM photographs of the fungal strains treated with the two AgNPs preparations showed flaccid structures, condensed hyphae, and shrunken surface compared with control cells. The data suggested that the biosynthesized P. oleracea AgNPs have antifungal properties against C. spicifera, M. phaseolina, and Bipolaris sp. These AgNPs may be considered a fungicide to protect different plants against phytopathogenic fungi.     

Prospective of biosynthesized L.satiVum oil/PEG/Ag-MgO bionanocomposite film for its antibacterial and anticancer potential

A substantial interest has been manifested in utilizing oil/metal oxide hybrid bionanocomposite, especially organic/ inorganic to design different biomedical applications. The present study reports the synthesis, characterization, antibacterial and anticancer properties of biogenic silver nanoparticles (AgNPs) and L.satiVum oil/PEG/Ag-MgO bionanocomposite. The fabricated AgNPs and L.sativum oil/PEG/Ag-MgO bionanocomposite were characterized by employing different spectroscopic (UV, FTIR, XRD) and microscopic (TEM, SEM) techniques. The particle size analysis showed that the mean size of 16.32 nm for AgNPS and 13.45 nm L.satiVum oil/PEG/Ag-MgO, indicating the excellent dispersion of Ag-MgO nanoparticles in the PEG– L.satiVum oil matrix. The antimicrobial activity of AgNPs and polymeric bionanocomposite was investigated against two pathogenic bacteria. The highest antibacterial effect was observed for bionanocomposite towards Gram-positive Staphylococcus aureus (27 mm) and Gram-negative Escherichia coli (25 mm) at 40 µg/well. The bionanocomposite completely vanished the bacterial growth (100%) at 80 µgmL⁻¹ concentrations. Moreover, the AgNPs and polymeric bionanocomposite was evaluated for anticancer activity against human cervical cancer cells (HeLa cells) at different doses (50, 250, 500, and 1000 µgmL⁻¹). The results showed polymeric bionanocomposite was stronger in inducing the HeLa cancer cell death than AgNPs. Overall, the fabricated L.satiVum oil/PEG/Ag-MgO bionanocomposite serve as a potential antimicrobial and anticancer agent and could be used in the development of novel drugs and health care products in near future.     

Fungicidal synergistic effect of biogenically synthesized zinc oxide and copper oxide nanoparticles against Alternaria citri causing citrus black rot disease

Citrus black rot disease being caused by Alternaria citri is a major disease of citrus plants with 30–35% economic loss annually. Fungicides had not been effective in the control of this disease during last few decades. In the present study, antifungal role of green synthesized zinc oxide (ZnO) and copper oxide (CuO) nanoparticles (NPs) were studied against Alternaria citri. Alternaria citri was isolated from disease fruits samples and was identified by staining with lacto phenol cotton blue. Furthermore, CuO and ZnO NPs were synthesized by utilizing the lemon peels extract as the reducing and capping agent. Nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. From the XRD data, the calculated size of CuO NPs was to be 18 nm and ZnO NPs was16.8 nm using Scherrer equation. The SEM analyses revealed the surface morphology of all the metal oxide NPs synthesized were rounded, elongated and or spherical in the shape. The zone of inhibition was observed to be 50 ± 0.5 mm by CuO NPs, followed by 51.5 ± 0.5 mm by ZnO NPs and maximum zone of antifungal inhibition was observed to be 53 ± 0.6 mm by mix metal oxide NPs. The results of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the synthesized nanoparticles showed that at the certain concentrations (80 mg ml^?1), these NPs were capable of inhibiting the fungal growth, whereas above that specified concentrations (100 mg ml^?1), NPs completely inhibited the fungal growth. Based on these findings, the green synthesized NPs can be used as alternative to fungicide in order to control the citrus black rot disease.     

Sunlight-driven rapid and facile synthesis of Silver nanoparticles using Allium ampeloprasum extract with enhanced antioxidant and antifungal activity

Green nanotechnology has acquired immense demand due to its cost-effective, eco-friendly and benevolent approach for the synthesis of nanoparticles. Among the biological methods, plants aid as a significant green resource for synthesizing nanoparticles that are safe and non-toxic for human use. In the present investigation, Silver nanoparticles (AgNPs) were synthesized using bulbs extract of Allium ampeloprasum under the influence of sunlight irradiation and characterized using different techniques. Distinct in-vitro assays were performed to test the antioxidant and anticandida potential of the synthesized AgNPs. Results suggested the efficient and rapid sunlight-driven synthesis of AgNPs using A. ampeloprasum extract. UV–Vis spectrum showed absorption peak at 446 nm which confirmed the formation of AgNPs. FTIR analysis suggested the presence of functional groups associated with flavonoids and sulfur compounds in A. ampeloprasum extract. The synthesized AgNPs showed Face Centred Cubic (FCC) structure with an average size of 35 nm. Spherical, quasi spherical, triangular and ellipsoidal morphology of the NPs were observed from the TEM micrograph. The synthesized AgNPs showed pronounced free radical scavenging potential for DPPH, ABTS?+ and H₂O₂ radicals. The anticandida potency of the synthesized AgNPs was observed as follows: C. albicans ≥ C. tropicalis ≥ C. glabrata ≥ C. parapsilosis ≥ C. krusei. Results showed that sunlight driven nanoparticle synthesis of AgNPs is rapid, facile and exhibit enhanced antioxidant and antifungal activity.     

Green synthesis of Silver nanoparticles using Streptomyces hirsutus strain SNPGA-8 and their characterization,antimicrobial activity,and anticancer activity against human lung carcinoma cell line A549

The current study described the systematic and detailed extracellular synthesis method of silver nanoparticles (AgNPs) using Streptomyces hirsutus strain SNPGA-8 by green synthesis method. The AgNPs were subjected for characterizations using UV–Vis, FTIR, TGA, TEM, EDX, XRD, and zeta-potential analyses. The antibacterial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli, Candida albicans, Alternaria alternata, Candida glabrata and Fusarium oxysporum was determined by the agar well diffusion technique. The cytotoxicity of AgNPs against human lung cancer (A549) was studied by MTT and ROS assays and capping of proteins of AgNPs from SDS-PAGE. In the UV–Vis., absorption peak was found at 418 nm, FTIR analysis revealed the infrared bands of specific functional groups from 3273 cm^?1 to 428 cm^?1; TEM data confirmed the spherical shape, smallest size of particle as 18.99 nm, while EDX analysis confirmed the elemental composition of AgNPs with 22.24% Ag. The XRD pattern confirmed the nature of AgNPs as crystalline, and zeta potential peak was found at ?24.6 mV indicating the higher stability. The AgNPs exhibited increased antimicrobial activity with increase in dosage volume and considerable MIC and MBC values against microbial pathogens. In the MTT cytotoxicity assay, the IC₅₀ value of 31.41 μg/mL is obtained against A549 cell line, suggesting the potential of AgNPs to inhibit the tumour cells; and ROS assay displayed increased ROS production with increase in treatment time. Based on the results, it is evident that Streptomyces hirsutus strain SNPGA-8 AgNPs are potentially promising to be applied for biomedical uses.     

Effect of substitution of groundnut with high glucosinolate mustard (Brassica juncea) meal on nutrient utilization,growth, vital organ weight and blood composition of lambs

Twenty-four 14-day-old weaner Avivastra (Russian Merino×Nali) male lambs were maintained for 180 days on ad libidum Cenchrus (Cenchrus ciliaris) hay and concentrate mixture (CM) contained groundnut meal (control) and mustard meal (MM group) as major protein source. The two CMs were isonitrogenous (21% CP) and isocaloric (2.78 Mcal ME kg⁻¹ DM), while, CM fed to MM group contained 24.6 mg glucosinolates g⁻¹ DM. Digestibility of nutrients was similar (P>0.05) in the two groups except for CP and hemicellulose, which was higher (P<0.05) in control. Urinary N loss was higher (P<0.01) in control than in MM group, whereas N retention (% of N intake and absorbed) was higher (P<0.01) in MM group compared to control. Dry matter (g kg⁻¹ BW) and glucosinolate intakes were higher in MM fed group, whereas DCP and ME intakes were similar (P>0.05) in the two groups. Average daily gain (ADG) was, however, 22% higher (P<0.01) in control than in MM group. Hemoglobin and albumin contents were lower (P<0.01) in MM group than in control. Serum thiocyanate content was 26.7 μg g⁻¹ in MM fed group, while it was not detected in control group. Thyroid weight was higher (P<0.01) while liver and kidney weights were lower (P<0.01) in MM group. Meat from dissected carcass of control group contained more protein and less fat, whereas the reverse was noticed in MM group. It is concluded that feeding mustard meal as protein supplement reduced growth rate and induced iodine deficiency. Carcass of lambs fed mustard meal had more fat and less protein.     

Short-term inhibition of prolactin secretion by naloxone treatment in the pregnant gilt

The involvement of endogenous opioids in modulation of prolactin (PRL) secretion during pregnancy in the pig was studied. Twenty-four crossbred pregnant gilts (150 ± 10 kg) were cannulated via the cephalic vein 24–48 h before treatment with 1 mg kg⁻¹ body weight of naloxone (NAL) or 3 ml of saline (CONT) i.v. at Day 40 (NAL, n = 6; CONT, n = 6) or Day 70 (NAL, n = 6; CONT, n = 6) of pregnancy. Blood plasma was collected at 15 min intervals from 1 h before to 3 h after treatment with NAL or saline. At Day 40 of pregnancy, administration of NAL caused a decrease in mean plasma PRL concentrations at 60 min, 120 min and 180 min post-treatment (NAL, 19.1 ± 1.3 ng ml⁻¹, P < 0.05; 15.8 ± 0.6 ng ml⁻¹, P < 0.001; 14.6 ± 0.7 ng ml⁻¹, P < 0.001, respectively) when compared with the CONT group (22.9 ± 0.7 ng ml⁻¹, 21.6 ± 0.6 ng ml⁻¹ and 22.4 ± 0.5 ng ml⁻¹, respectively). Mean plasma estradiol concentration was higher (P < 0.01) in the NAL group during the second and third hour post-treatment than in the CONT group. At Day 70 of pregnancy, infusion of NAL also decreased (P < 0.001) plasma PRL concentrations at 60 min, 120 min and 180 min after treatment (20.1 ± 1.6 ng ml⁻¹, 16.2 ± 1.5 ng ml⁻¹ and 14.8 ± 0.4 ng ml⁻¹, respectively) compared with the CONT group (33.4 ± 1.7 ng ml⁻¹, 34.1 ± 1.3 ng ml⁻¹ and 29.1 ± 0.9 ng ml⁻¹, respectively). Estradiol concentrations were not different (P > 0.05) between groups in this stage of gestation. Mean concentrations of progesterone were similar during the pre- and post-treatment periods in both stages of pregnancy.These data would suggest a possible role of the opioids in modulation of PRL secretion at these stages of pregnancy in the pig.     

The influence of H2 partial pressure on biogenic palladium nanoparticle production assessed by single-cell ICP-mass spectrometry

The production of biogenic palladium nanoparticles (bio-Pd NPs) is widely studied due to their high catalytic activity, which depends on the size of nanoparticles (NPs). Smaller NPs (here defined as <100 nm) are more efficient due to their higher surface/volume ratio. In this work, inductively coupled plasma-mass spectrometry (ICP-MS), flow cytometry (FCM) and transmission electron microscopy (TEM) were combined to obtain insight into the formation of these bio-Pd NPs. The precipitation of bio-Pd NPs was evaluated on a cell-per-cell basis using single-cell ICP-MS (SC-ICP-MS) combined with TEM images to assess how homogenously the particles were distributed over the cells. The results provided by SC-ICP-MS were consistent with those provided by “bulk” ICP-MS analysis and FCM. It was observed that heterogeneity in the distribution of palladium over an entire cell population is strongly dependent on the Pd²⁺ concentration, biomass and partial H₂ pressure. The latter three parameters affected the particle size, ranging from 15.6 to 560 nm, and exerted a significant impact on the production of the bio-Pd NPs. The TEM combined with SC-ICP-MS revealed that the mass distribution for bacteria with high Pd content (144 fg Pd cell⁻¹) indicated the presence of a large number of very small NPs (D50 = 15.6 nm). These results were obtained at high cell density (1 × 10⁵ ± 3 × 10⁴ cells μl⁻¹) and H₂ partial pressure (180 ml H₂). In contrast, very large particles (D50 = 560 nm) were observed at low cell density (3 × 10⁴ ± 10 × 10² cells μl⁻¹) and H₂ partial pressure (10–100 ml H₂). The influence of the H₂ partial pressure on the nanoparticle size and the possibility of size-tuned nanoparticles are presented.     

Accumulation and detoxification dynamic of cyanotoxins in the freshwater shrimp Palaemonetes argentinus

The uptake and accumulation of microcystin-LR (MC-LR) in the shrimp Palaemonetes argentinus was investigated using both laboratory and field assays. Shrimps were exposed in aquarium during 1, 2, 3 and 7 days to 1, 10 and 50 μg L⁻¹ MCLR. Accumulation (0.7 ± 0.2 μg MC-LR g⁻¹) was observed after three days exposures to 50 μg L⁻¹ toxin. Then, shrimps were relocated in fresh water (free of MCLR) to verify the detoxification dynamic, showing a drop to 0.18 ± 0.01 μg MCLR g⁻¹ after three days. The activity of glutathione-S-transferase, measured in the microsomal fraction (mGST), was significantly increased during the exposure period, with further increment during the detoxification period. Furthermore, cytosolic GST (sGST) and glutathione reductase (GR) increased their activities during detoxification, while inhibition was observed for catalase (CAT) with no significant changes for glutathione peroxidase (GPx). Current results suggest that GSH conjugation could be an important MC detoxification mechanism in P. argentinus and that MCLR induce oxidative stress in this shrimp.Field exposures were carried out in San Roque Reservoir (Córdoba, Argentina) after a cyanobacteria bloom. Nodularin (Nod) presence was measured for the first time in this waterbody (0.24 ± 0.04 μg L⁻¹), being the first report of Nod in South America freshwaters. Nod was also detected in Palaemonetes argentinus (0.16 ± 0.03 μg g⁻¹) after three weeks of exposure in this reservoir, with the concomitant activation of mGST, sGST and CAT.Although internal doses of Nod were low throughout the exposure, they were enough to cause biochemical disturbances in Palaemonetes argentinus.Further laboratory studies on Nod accumulation and antioxidant responses in Palaemonetes argentinus are necessary to fully understand these field results. P. argentinus should be considered a potential vector for transferring cyanotoxins to higher trophic levels in aquatic environments.     

Green synthesis of silver nanoparticles with Dalbergia spinosa leaves and their applications in biological and catalytic activities

The phytosynthesis of silver nanoparticles (AgNPs) by Dalbergia spinosa leaves (DSL) in aqueous extract was investigated. AgNPs were characterized by UV–visible absorption spectroscopy (UV–vis), transmission electron microscopy (TEM) and Fourier transform infra red spectrophotometry (FTIR). The results showed that the increase in the initial extract concentration at room temperature increased the mean size and widened the size distribution of the AgNPs, leading to a red shift and broadening the surface plasmon resonance absorption (439 nm). The results showed that the reducing sugars and flavonoids were primarily responsible for the bioreduction of silver ions and that their reductive capability was promoted at 36 °C. TEM analysis showed that the AgNPs were nearly spherical in shape with an average size of 18 ± 4 nm. When evaluated for in vitro antioxidant activity by DPPH, NO, hydrogen peroxide radicals, reducing power and CUPRAC assay methods in addition to anti-inflammatory activity by HBRC method, the silver nanoparticles exhibited considerably enhanced antioxidant and anti-inflammatory activity at the test doses when compared with that of the standards and the plant extract. Finally, the antibacterial activity of the AgNPs against two Gram-positive bacteria and two Gram-negative bacteria showed moderate antibacterial activity when compared with the standard and the plant extract. The synthesized silver nanoparticles were also effective in the catalytic reduction of 4-nitrophenol (4-NP) into 4-aminophenol (4-AP).     

A study on feeding ammoniated and processed barley to feedlot steers

A total of 120 commercial crossbred steer calves (284±1.9 kg) were allocated in a 2×2 arrangement to two barley processing methods; whole (W) or rolled (R) barley and two ammoniation treatments; ammoniated (A) or non-ammoniated (N) barley. Steers were randomly allocated to twelve pens with 10 steers per pen and 3 pens (replications) per diet. The study was divided into two stages, growing (0–84 day) and finishing (85–196 day). Average daily gain (ADG) for the overall 196 day period was affected by processing (p<0.01) averaging 1.10 and 1.20 kg day⁻¹ for steers on W and R barley, respectively. Steers on the R barley gained 19.6% more than those on W barley during the growing stage and 0.8% more during the finishing stage. There was a trend towards an improvement (p=0.06) in overall ADG by ammoniation. The ADG of steers was significantly higher (p<0.01) during the finishing (1.22 kg day⁻¹) than during the growing (1.06 kg day⁻¹) stage. Feed efficiency was better with R than with W barley (6.8 vs. 7.7; p=0.02). Processing and ammoniation had no effect (p>0.05) on carcass traits or grades.