جستجوی مقالات مرتبط با کلیدواژه « agnps » در نشریات گروه « زیست شناسی »

Today, the production and use of materials with nanometer diversity is increasing day by day due to the unique and fascinating features of these materials. Until now, various physical and chemical methods have been used for the synthesis of silver nanoparticles (AgNPs), but the use of plants for the synthesis of AgNPs is very fast, simple, non-toxic, and environmentally friendly. In this research, the aqueous extract (AE) of Capparis plants was used for the biosynthesis of AgNPs. The color of the silver nitrate solution changed to reddish color after adding the extract. The Antimicrobial activity of AgNPs against Streptococcus pyogenes, Streptococcus pneumoniae, S. saprophyticus, Hafnia alvei,  Acinetobacter. baumannii, Enterococcus faecalis, Proteus mirabilis, Serratia marcescens, Staphylococcus aureus bacteria were investigated by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) using microdilution method. The amount of total phenol and flavonoids in the methanolic extract (ME) of capparis leaves was equal to 229.9- 28.09 mg per gram of dry matter. The antioxidant properties of the ME of capparis were 85.18%. The greatest effect of the ME of the medicinal plant capparis was 0.2315 on the inactivity of E. coli and the greatest effect of green AgNPs synthesized from the AE of the medicinal plant Capparis with ELISA of 0.3740 was on the inactivity of S. mutanis. The maximum diameter of the inhibitor zone (MDIZ) was 5.5 mm due to the inactivity of H. alvi bacteria. The results of this research showed that the leaf extract of the Capparis spinosa f. inermis Knocheplant is capable of synthesizing AgNPs and the synthetic nanoparticles showed good antimicrobial activity against pathogenic strains in vitro.

Lactuca undulata Ledeb. is a medicinal plant belonging to the Asteraceae family. Chicoric acid is one of the main derivatives of caffeic acid, with various pharmacological and biological properties. This study was conducted to optimize cell suspension culture and enhance chicoric acid production in L. undulata by eliciting secondary metabolites using silver nitrate (AgNO3) and silver nanoparticles (AgNPs). Seeds were cultured on ½ MS medium to produce sterile seedlings. In order to produce callus, leaf and root explants were obtained from 2 months old sterile seedlings and placed on ½ MS medium containing 2 mg/L 2,4-D/ plus 0.5 mg/L Kin and 2 mg/L 2,4-D/ plus 2 mg/L Kin, respectively. Cell suspension cultures from leaf and root-derived calluses were established and treated with different concentrations (0, 2, and 4 mg/L) of AgNO3 and AgNPs during the logarithmic growth phase. Then cells were harvested after 24, 48, and 72 hours. Overall, elicitation by AgNPs was more effective on chicoric acid production compared to AgNO3. The highest amounts of chicoric acid (9.7 ± 0.48 mg/g DW) and caffeic acid (15.3 ± 0.8 mg/L) were found in leaf and root cell suspension cultures after 48 hours of exposure to 4 and 2 mg/L AgNPs, respectively. In contrast, 4 mg/L of AgNO3 stimulated the greatest accumulation of chlorogenic acid (4.56 ± 0.3 mg/g DW) in root cell culture at 72 h after elicitation. The current results revealed that the use of AgNPs can be an efficient strategy to improve cichoric acid accumulation in cell suspension culture.

Nanoparticles (NPs) have received much attention recently in various areas of industry, biomedical, and agricultural sectors worldwide. It is important to recognize the consequences of the use and application of NPs and their interaction with ecosystems components including plants, whether in the environmental area or in physiology and crop production. The present study aimed to investigate the changes in essential oil content and composition of Thymus daenensis Celak., Thymus fedtschenkoi Ronniger and Thymus vulgaris L. under silver nanoparticles (AgNPs) and silicon nanoparticles (SiNPs) in four levels (0, 30, 60, 100 ppm). The essential oil content increased at all stress levels and in all three species. The amount of monoterpene hydrocarbons in T. fedtschenkoi increased, while it decreased in other two species. The amount of sesquiterpentes, except for oxygenated sesquiterpenes in T. daenensis, increased slightly. Compared to other factors, the type of plant species was more determinative in response to treatments. Overall, both AgNPs and SiNps treatments had a distinct effect. However, no interpretable results were observed between the different levels of both treatments.

Dermatophytosis is the common cutaneous infections in humans and animals, which is caused by the keratinophylic fungus called dermatophytes. In recent years, drug-resistance in pathogenic fungi, including dermatophytes to the current antifungal have been increased. The aim of this study was to evaluate the antifungal efficacy of AgNPs against Microsporum canis, Trichophyton mentagrophytes, and Microsporum gypseum. The antifungal susceptibility of nano-silver particles (AgNPs) compared with Griseofulvin (GR). Its efficacy was investigated against three strains of dermatophytes by both agar dilution and broth microdilution test (BMD). The average minimum inhibitory concentration (MIC) of Ag-NPs on M. canis, T. mentagrophytes and M. gypseum were 200, 180, and 170 μg/ml, respectively. Whereas these strains showed MIC of 25, 100 and 50 μg/ml for Griseofulvin (GR). Our finding indicated that the AgNPs was less active than Griseofulvin (GR) but it had anti-dermatophytic effect.