Biochemical repercussions of light spectra on nitrogen metabolism in spinach (Spinacia oleracea) under a controlled environment.

Introduction: Selecting appropriate light spectra of light-emitting diodes (LEDs) and optimal nutrient composition fertilizers has become integral to commercial controlled environment agriculture (CEA) platforms. Methods: This study explored the impact of three LED light regimes (BR: Blue17%, Green 4%, Red 63%, Far-Red 13% and infrared 3%, BGR; Blue 20%, Green 23%, Red 47%, Far-Red 8% and infrared 2%; and GR; Blue 25%, Green 41%, Red 32%, and Far-Red 2%) and nitrogen levels (3.6 and 14.3 mM N) on spinach (Spinacea oleracea). Results: Under limited nitrogen (3.6 mM), BGR light increased the fresh shoot (32%) and root (39%) biomass than BR, suggesting additional green light's impact on assimilating photosynthates under suboptimal nitrogen availability. Reduced chlorophyll (a and b) and carotenoid accumulation, electron transport rate (ETR), and higher oxalates under limited nitrogen availability highlighted the adverse effects of red light (BR) on spinach productivity. Increased activities of nitrogen-associated enzymes (GOGAT; Glutamate synthase, GDH; NADH-Glutamate dehydrogenase, NR; Nitrate reductase, and GS; Glutamine synthetase) in spinach plants under BGR light further validated the significance of green light in nitrogen assimilation. Amino acid distributions remained unchanged across the light spectra, although limited nitrogen availability significantly decreased the percent distribution of glutamine and aspartic acid. Conclusion: Overall, this study demonstrated the favorable impacts of additional green light on spinach productivity, as demonstrated under BGR, than GR alone in response to nitrogen perturbation. However, the exact mechanisms underlying these impacts still need to be unveiled. Nevertheless, these outcomes provided new insights into our understanding of light spectra on spinach nitrogen metabolism.

Effect of herbal compounds on coronavirus; a systematic review and meta-analysis.

BACKGROUND: The new coronavirus (COVID-19) has been transmitted exponentially. Numerous studies have been performed in recent years that have shown the inhibitory effect of plant extracts or plant-derived compounds on the coronavirus family. In this study, we want to use systematic review and meta-analysis to answer the question, which herbal compound has been more effective? MAIN BODY: The present study is based on the guidelines for conducting meta-analyzes. An extensive search was conducted in the electronic database, and based on the inclusion and exclusion criteria, articles were selected and data screening was done. Quality control of articles was performed. Data analysis was carried out in STATA software. CONCLUSION: Due to the variety of study methods, definitive conclusions are not possible. However, in this study, we attempted to gather all the available evidence on the effect of plant compounds on SARS-COV-2 to be used for the development and use of promising antiviral agents against this virus and other coronaviruses. Trypthantrin, Sambucus extract, S. cusia extract, Boceprevir and Indigole B, dioica agglutinin urtica had a good effect on reducing the virus titer. Also among the compounds that had the greatest effect on virus inhibition, Saikosaponins B2, SaikosaponinsD, SaikosaponinsA and Phillyrin, had an acceptable selectivity index greater than 10. Andrographolide showed the highest selectivity index on SARS-COV-2. Our study confirmed insufficient data to support alkaloid compounds against SARS-COV-2, and the small number of studies that used alkaloid compounds was a limitation. It is recommended to investigate the effect of more alkaloid compounds against Corona virus.

Alginate scaffolds improve functional recovery after spinal cord injury.

PURPOSE: In this systematic review and meta-analysis, the use of alginate for the repair of the damaged spinal cord was investigated. METHODS: After an extensive search of databases including MEDLINE, SCOPUS, EMBASE and Web of Science, an initial screening was performed based on inclusion and exclusion criteria. The full text of related articles was reviewed and data mining was performed. Data were analyzed by calculating the mean of ratios between treated and untreated groups using STATA software. Subgroup analysis was also performed due to heterogeneity. Articles were subjected to quality control and PRISMA guidelines were followed. RESULTS: Twelve studies and 17 experiments were included in the study. After SCI, alginate hydrogel had a moderate effect on motor function recovery (SMD = 0.64; 95% CI 0.28-1.00; p < 0.0001) and alginate scaffolds loaded with drugs, growth factors, or cells on the SCI group compared with untreated SCI animals showed has a strong effect in the treatment of SCI (SMD = 2.82; 95% CI 1.49-4.145; p < 0.0001). Treatment with drug/cell in combination with alginate was more strongly significant compared to the groups treated with drug/cell alone (SMD = 4.55; 95% CI 1.42-7.69; p < 0.0001). Alginate alone or in combination therapy when used as an implant, had a more significant effect than injection. CONCLUSION: These findings suggest that alginate is an efficient scaffold for functional recovery and even a much better scaffold for drug/cell delivery after SCI.

Antibacterial effect of cerium oxide nanoparticle against Pseudomonas aeruginosa.

BACKGROUND: Antibiotics have been widely used for the treatment of bacterial infections for decades. However, the rapid emergence of antibiotic-resistant bacteria has created many problems with a heavy burden for the medical community. Therefore, the use of nanoparticles as an alternative for antibacterial activity has been explored. In this context, metal nanoparticles have demonstrated broad-spectrum antimicrobial activity. This study investigated the antimicrobial activity of naked cerium oxide nanoparticles dispersed in aqueous solution (CNPs) and surface-stabilized using Pseudomonas aeruginosa as a bacterial model. METHODS: Gelatin-polycaprolactone nanofibers containing CNPs (Scaffold@CNPs) were synthesized, and their effect on P. aeruginosa was investigated. The minimum inhibitory and bactericidal concentrations of the nanoparticls were determined in an ATCC reference strain and a clinical isolate strain. To determine whether the exposure to the nanocomposites might change the expression of antibiotic resistance, the expression of the genes shv, kpc, and imp was also investigated. Moreover, the cytotoxicity of the CNPs was assessed on fibroblast using flow cytometry. RESULTS: Minimum bactericidal concentrations for the ATCC and the clinical isolate of 50 µg/mL and 200 µg/mL were measured, respectively, when the CNPs were used. In the case of the Scaffold@CNPs, the bactericidal effect was 50 µg/mL and 100 µg/mL for the ATCC and clinical isolate, respectively. Interestingly, the exposure to the Scaffold@CNPs significantly decreased the expression of the genes shv, kpc, and imp. CONCLUSIONS: A concentration of CNPs and scaffold@CNPs higher than 50 µg/mL can be used to inhibit the growth of P. aeruginosa. The fact that the scaffold@CNPs significantly reduced the expression of resistance genes, it has the potential to be used for medical applications such as wound dressings.

Effect of graphene / metal nanocomposites on the key genes involved in rosmarinic acid biosynthesis pathway and its accumulation in Melissa officinalis.

BACKGROUND: Recently, numerous investigations have been done to study graphene and silver nanoparticle in the fields of agriculture and medicine. In the present study, the green synthesis of nanoparticles with two concentrations (0, 40, 60 mM) and their effect on the molecular and biochemical biosynthesis pathway of rosmarinic acid in a new method, low cost, and safe for the environment has been investigated. The transcript levels of key genes in the rosmarinic acid biosynthesis pathway (Tyrosine aminotransferase, rosmarinic acid synthase, and phenylalanine-ammonia lyase) were studied using real-time quantitative polymerase chain reaction. Then, the rosmarinic acid content was evaluated using HPLC. RESULTS: The results showed that a concentration-dependent manner was observed in treated plants. At the biochemical level, the use of nanocomposites at concentration of 40 mM showed higher soluble carbohydrate (37%), flavonoids (21%), total phenol (35%) as well as total protein (47%) compared to the control plants. HPLC results showed that rosmarinic acid content in the treated plants with a low concentration of nanocomposite (40 mM) was more affected than plants treated with a high concentration of nanocomposite (60 mM) (26%) and also compared to other treatments. At the molecular level, the result showed that Tyrosine aminotransferase and rosmarinic acid synthase gene expression was positively correlated with both silver nanoparticle concentrations and nanocomposite treatments, but phenylalanine-ammonia lyase gene expression was positively correlated only with nanocomposite at 40 mM concentration. CONCLUDE: It can conclude that the nanocomposite at low concentration is more likely to induce molecular and biochemical parameters. And also, in the rosmarinic acid biosynthesis pathway, the Tyrosine aminotransferase -derived pathway is more efficient than the phenylalanine-ammonia lyase -derived pathway by causing a nano-elicitor. Therefore, it was concluded that studied elicitor at low concentration, can create plants with higher production capacity.

Physio-chemical responses of exogenous calcium nanoparticle and putrescine polyamine in Saffron (Crocus sativus L.).

The aim of this study was to investigate the effect of calcium nanoparticles (CaNP) and putrescine polyamine on some physiological and biochemical properties of saffron (Crocus sativus L.) under the control condition. Saffron corm was treated by different concentrations of putrescine (0, 0.25, 0.5, 1, 2 mM) and CaNP (0, 0.25, 0.5, 1, 1.5 g/l). The treatment of corm with putrescine and CaNP separately caused a significant increase in morphological parameters. Changes in biochemical parameters were also significant. Compared to other concentrations, the highest concentration of putrescine (1 mM) and CaNP (1 g/l) treatment in the plant showed the greatest effect. The combined effect of putrescine and CaNP treatment on morphological parameters was significant. The results of HPLC analysis showed that CaNP treatment alone is more effective on crocin, picrocrocin, and safranal content than the combined effect of CaNP and putrescine. The present study reported the functional potential of CaNP and putrescine combination to increase growth and phytochemical properties in Crocus sativus.

Comparison between the effects of potassium phosphite and chitosan on changes in the concentration of Cucurbitacin E and on antibacterial property of Cucumis sativus.

BACKGROUND: Cucurbitacins are mostly found in the members of the family Cucurbitaceae and are responsible for the bitter taste of cucumber. Pharmacological activities such as anti-bacterial and anti-tumor effects have been attributed to these structurally divers triterpens. The aim of this study was to investigate the effect of potassium phosphite (KPhi) and chitosan on Cucurbitacin E (CuE) concentration in different tissues of Cucumis sativus. The antibacterial effect of plant ethanolic extracts was also examined against E.coli PTCC 1399 and Pseudomonas aeruginosa PTCC 1430 bacterial strains. METHODS: After emergence of secondary leaves, cucumber plants were divided into 4 groups (each group consisted of 6 pots and each pot contained one plant) and different treatments performed as follows: group1. Leaves were sprayed with distilled water (Control), group 2. The leaves were solely treated with potassium phosphite (KPhi), group 3. Leaves were solely sprayed with chitosan (Chitosan), group 4. Leaves were treated with KPhi and chitosan (KPhi + chitosan). The KPhi (2 g L-1) and chitosan (0.2 g L-1) were applied twice every 12 h for one day. Fruits, roots and leaves were harvested 24 h later. The ethanolic extract of plant organs was used for determination of CuE concentration using HPLC approach. The antimicrobial activity was evaluated by the agar well diffusion method. The experiments were arranged in a completely randomized design (CRD) and performed in six biological replications for each treatment. Analysis of variance was performed by one-way ANOVA and Dunnette multiple comparison using SPSS. RESULTS: The highest level of CuE was recorded in fruit (2.2 g L-1) of plants under concomitant applications of KPhi and chitosan. Result of antibacterial activity evaluation showed that under concomitant treatments of KPhi and chitosan, fruit extract exhibited the highest potential for activity against E. coli PTCC 1399 (with mean zone of inhibition equal to 36 mm) and Pseudomonas aeruginosa PTCC 1430 (with mean zone of inhibition equal to 33 mm). CONCLUSIONS: KPhi and chitosan can induce production of CuE compound and increase antibacterial potential of cucumber plant extract. The application of KPhi and chitosan may be considered as promising prospect in the biotechnological production of CuE.