antioxidant

Salinity stress is one of the most important abiotic stresses in many areas of Iran, especially in the fields of medicinal plants, which has caused many problems. The basil plant is one of the important medicinal plants that is used in various industries due to its phenolic compounds. Climate change and rapid population growth seriously affect the world's agricultural food security. To deal with these threats, researchers must use new technologies. In this regard, so far, several nanoparticles, such as silver nanoparticles, have been used for seed germination, plant growth and tolerance to biological stresses in a number of agricultural plants. Based on this, the present study was conducted as a factorial in the form of a completely randomized design with two factors and three replications on basil seedlings. Experimental factors, including salinity at 0, 75, and 150 mM levels, were used as plant foot application and nanosilver at 0 and 75 ppm levels as foliar spraying. Some biochemical indicators, such as the content of total phenol, hydrogen peroxide and the activity of antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (AXP), catalase (CAT), guaiacol peroxidase (POX) and the enzyme phenylalanine ammonialyase (PAL), in the root and shoot, were evaluated. The obtained results showed that the simultaneous application of salt and nanosilver led to a significant increase in total phenol content in shoot and root (46.89% and 45.48% increase, respectively), increased PAL activity in shoot and root (respectively 32.51% and 41.56% increase), and also increased the activity of SOD antioxidant enzymes in shoot and root (58.97% and 43.11% increase, respectively), CAT (63.76% and 73.31%), and APX (74.18 and 31.79 percent). Also, the results showed a decrease in hydrogen peroxide content in the shoot and root compared to the control. In general, it seems that nanosilver has been able to increase the tolerance of basil plants to salt stress by reducing the content of hydrogen peroxide and increasing the activity of antioxidant enzymes and the content of phenol.

In order to investigate the effect of drought stress and biofertilizers from Mycorrhiza, azotobacter and azospirillum on the yield and biochemical characteristics of two wheat cultivars, a randomized complete block design in the form of split-factorial experiment was conducted with three replications in the crop year 2014-2015 in Poldakhter city. Drought stress in the main plots consisted of three levels of full irrigation, interruption of irrigation from the spike stage and interruption of irrigation from the seed filling stage. The sub-plots factorially included biofertilizer factor in four levels of control (without fertilizer), mycorrhiza inoculation, mycorrhiza+aztobacter inoculation, mycorrhiza+azespirillum inoculation, and the cultivar factor included Chamran and Behrang cultivars. Drought stress in the flowering stage caused a decrease in the content of chlorophylls and most elements, including nitrogen, phosphorus, potassium, copper and manganese, in shoots and seeds, but increased the content of proline and antioxidant enzymes. The content of most of the elements in aerial parts and seeds and the concentration of proline and antioxidant enzymes were higher in the Chamran variety than Behrang. The simultaneous use of mycorrhizae and growth-stimulating bacteria increased the content of most elements in shoots and seeds compared to the control treatment, but it decreased the concentration of proline and antioxidant enzymes. The mutual effects indicated the different responses of cultivars to the levels of biofertilizer in different drought stress treatments. In general, the Chamran variety is recommended by combining mycorrhiza with Azotobacter or Azespirillum.

Planting date, nitrogen biofertilizer and weed control are three factors affecting biochemical traits of wheet in dryland condition, so an experiment was carried out as a split-factorel design with three replications on Kohdasht variety at Kamalvand research station in Khorramabad in two crop years 2015-2016 and 2016-2017. Planting date factor (6 and 21 November) was in main plots and nitrogen biofertilizer (control, urea, nitrogen biofertilizer, and combined fertilizer) and weed control (weeding and weed interference) factors were hn sub plots in factorial arrange. The results showed that the amount of phosphorus and potassium of shoots and seed potassium was significantly higher on the first planting date than on the second planting date, but the amount of proline and seed starch increased on the second planting date. Among the fertilizer levels, the highest amount of peroxidase and seed starch were observed from no application of fertilizer and the highest amount of seed nitrogen was observed from the application of combined fertilizer. The amount of peroxidase activity, seed phosphorus and seed starch in the weed interference treatment was significantly higher than in the weeding treatment, but on the contrary, the amount of shoot zinc, seed zinc and seed protein in the weeding treatment was more than the interference treatment. The highest amount of seed protein from the first planting date of combined and chemical fertilizer application (12.84% and 12.73%, respectively) and the lowest amount were observed from the second planting date and no application of fertilizer and application Chemical fertilizers (10.83 and 10.85%). The highest amount of chlorophyll a, b and total chlorophyll (5.51, 4.48 and 10.0 mg/g FW, respectively) and shoot phosphorus (0.49 percent) was observed from the application of combined fertilizer and weeding, the highest amount of proline and potassium of shoot was observed from the absence of application of fertilizer and weeding (8.3 mg/g FW and 2.96%, respectively) and the highest amount of seed potassium was observed from the application of combined fertilizer and interference (0.55 mg/kg). On the first planting date, the highest amount of shoot nitrogen was observed from the application of combined fertilizer and weeding (2.32%) and the highest amount of grain iron was observed from the pure or combined application of biological fertilizer and weeding (72.96 mg/kg); However, on the second planting date, the highest amount of aerial organ nitrogen was observed from the application of combined fertilizer and weeding (2.91%) and the highest amount of grain iron was observed from the application of biological fertilizer and weeding or interference (63.5 mg/kg).

One of the basic ways to increase the storage life of fruits is to use treatments that can increase their quality and marketability. In this research, compounds such as proline and GABA have been used due to their antioxidant properties in order to protect cell membranes, maintain quality and increase shelf life during the post-harvest period in sweet lemon fruits. The treatments included concentrations of GABA 100 and 200 mM/l, proline 250 and 500 mM/l, and distilled water (control). Then the desired fruits were treated in the desired solutions for 5 minutes by the immersion method. After the fruits were completely dried, they were placed in packs of 5 and transferred to the cold room, where they were kept at a temperature of 12 degrees Celsius for 4 months. Once every 30 days, a number of fruits were taken out of the cold room, and similar traits were observed. The percentage of fruit damage, organic acids, amount of dissolved solids, activity of peroxidase and catalase enzymes, hydrogen peroxide, lipid peroxidation and leakage were investigated. The results showed that the amount of damage, ion leakage, hydrogen peroxide and lipid peroxidation in the fruits treated with GABA 200 mM/l and proline 250 mM/l decreased compared to the control. The treatment of sweet lemon fruits with GABA 200 mM/l and proline 250 mM/l has led to an increase in the amount of soluble solids and organic acids, as well as the activity of peroxidase and catalase enzymes. Therefore, the use of GABA and proelin can be recommended to increase the storage life of fruit at the commercial level.

The medicinal plant Alhagi persarum is known for its resilience in arid regions and holds an important place in traditional Iranian medicine. This study aimed to investigate the antioxidant properties, phytochemical content, and inhibitory effects of silver nanoparticles (AgNPs), which were synthesized using an aqueous extract of A. persarum, on the production of amyloid nanofibers. The compounds present in the extract were analyzed using gas chromatography-mass spectrometry (GC-MS), the inhibition rate of free radicals was measured using the DPPH assay, and the inhibition rate of the acetylcholinesterase enzyme was assessed using spectrometric methods. The inhibition of amyloid fibril production was examined using fluorescence spectroscopy and confirmed through scanning electron microscopy. The production of AgNPs was verified by both visible and infrared spectroscopy, and their structure was analyzed using dynamic light scattering (DLS), zeta potential measurements, scanning electron microscopy (SEM), and X-ray diffraction spectroscopy (XRD). The extract contained a variety of compounds, with thiophene, octadecanoic acid, and inositol being the most abundant. There was a direct relationship between the concentration of nanoparticles and antioxidant activity, whereas an inverse relationship was observed between nanoparticle concentration and the inhibitory effects on the acetylcholinesterase enzyme as well as the inhibition of amyloid fibril formation. The A. persarum plant extract shows promise as a dietary supplement to help mitigate clinical complications in patients with Alzheimer's disease.

Plants are a rich source of antioxidant compounds that can help prevent oxidative stress. The present study aimed to evaluate the antioxidant properties of different extracts obtained from Ziziphora tenuior L. Leaves and stems of the plant were collected from the mountains around Quchan in the spring of 2022 and subsequently dried. Extraction of the dried plant powder was performed using maceration (cold), hot, and microwave methods, employing solvents such as water, methanol, ethanol, a water-ethanol mixture (1:1), acetone, and dichloromethane. We measured the total content of phenolic and flavonoid compounds, as well as the antioxidant activity of the extracts using the DPPH method. Additionally, the chemical compounds in the essential oil derived from the leaves and stems were identified using the Cloninger method with a GC/MS device. The results revealed that the methanolic extract, obtained through the warm extraction method, contained the highest amount of phenolic compounds (74.26 mg/g) and the highest amount of flavonoid compounds (108.12 mg/g) through maceration. Furthermore, the warm methanolic extract exhibited strong inhibitory activity (69.52%). In terms of the essential oil's composition, the highest percentages of known chemical compounds were found to be polygon (49.05%), piperitone (11.61%), and menthone (9.23%). Overall, our findings indicate that employing various extraction methods can effectively enhance the extraction of antioxidant compounds from this plant. Given its high antioxidant properties, Z. tenuior L. shows potential for use as a natural antioxidant in the food and pharmaceutical industries.

The fig (Ficus carica L.) holds a significant position as one of Iran's essential subtropical fruits with medicinal characteristics. Given the considerable genetic diversity among fig genotypes in Iran, it is necessary to assess its genetic resources. This study, conducted in 2023, aimed to compare the morphological and antioxidant traits of the first and main crops of four fig genotypes. Fruit samples were randomly collected in June (first crop) and August (main crop) for analysis based on fig descriptors. The findings revealed that the first crop of the Pardis genotype exhibited the highest fruit weight (113.85 g). Similarly, the largest fruit diameter was recorded in the first crop of the Pardis genotype (56.66 mm) followed by the first crop of Turk genotype (53.42 mm). In most genotypes, the first crop displayed higher weight, diameter, neck length, and flesh thickness; however, the main crop showed higher values in pulp diameter. The first crop fruits were longer (69 mm) and more elongated. A significant difference was observed between the first crop and the main crop across four genotypes in terms of soluble solids, pH, total phenol, total flavonoids, and antioxidant activity, with the first crop demonstrating superior values in all these aspects. Notably, there was a significant variance in antioxidant activity among genotypes, with the Turk genotype exhibiting the highest antioxidant activity (82.8% free radicals). The fruiting season likely plays a pivotal role in determining the antioxidant activity level and phenolic content, suggesting that the first crop of fig genotypes possesses enhanced medicinal properties.

Melatonin has different and important roles in many aspects of plant growth and development. Recently, it has been found that melatonin has antioxidant properties and plays a vital role in the processes of germination, maturation, aging, cell protection, and resistance to biotic and abiotic stresses. In this study, the effect of different concentrations of melatonin (0, 50, 100, and 200 μM) on yield, growth traits and some biochemical characteristics of hot pepper (Capsicum annuum) under different levels of deficit irrigation (irrigation after 40, 80 and 120 mm of evaporation from a class A pan) was investigated. The split plot experiment was carried out in the form of a randomized complete block design with three replications. The results showed that the reduction of irrigation decreased the growth and yield of the plant and increased the content of proline and malondialdehyde. Application of melatonin at all irrigation levels improved the growth and performance of pepper in field conditions. Also, melatonin foliar application decreased the content of proline and malondialdehyde and increased chlorophyll and carotenoid compared to the control. The concentration of 200 μM melatonin had a better effect on the growth and yield of pepper than other concentrations. Also, the effectiveness of the melatonin hormone was observed more at the irrigation level of 120 mm of evaporation. In general, the results of this research showed that the use of melatonin (especially in concentrations of 100 and 200 μM) reduced the effects of drought stress in pepper plants by increasing the content of chlorophyll and reducing the accumulation of malondialdehyde and proline.

Microgreens are considered a functional food that can be so useful for increasing the health level of society. This experiment was conducted in factorial format based on a completely randomized design with two factors. The first factor, light spectrum, was investigated at four levels, and the second factor, sulfur nutrition, at two levels (0 and 60 mg/liter). The light treatments included different ratios of red (R) and blue (B) light (R1B2, R1B1, R2B1, and R3B1). The highest leaf length was recorded in the R3B1 treatment without sulfur feeding, which was significantly higher than all other treatments used. The length of the stem in the combined treatment of R3B1 with sulfur feeding showed the highest figure. The highest amount of total chlorophyll was obtained in R1B2 treatment with sulfur feeding, although their difference with R3B1 treatment with sulfur feeding and R2B1 without sulfur feeding was not statistically significant. In carotenoid pigment, the highest amount was seen in R2B1 treatment without sulfur, which did not show a significant difference with R1B2 without sulfur feeding. The total antioxidant activity showed the highest value in R3B1 treatment without sulfur, and its difference was not significant between R1B1 treatment without sulfur and R1B1 with sulfur feeding. The maximum calculated phenol was recorded in R2B1 treatment without sulfur, which was not significantly different from R1B2 treatment without sulfur and R3B1 with sulfur feeding. The most flavonoids were obtained in the R1B2 treatment without sulfur feeding, which was significantly more than all other treatments. Since the high proportion of red light in conditions without sulfur nutrition caused proper morphological growth and also increased the antioxidant capacity of the plant, therefore the mentioned treatment is recommended for the production of broccoli microgreens under artificial light.

Selection of cultivars adapted to drought stress conditions in each region plays an important role in achieving production potential in that region. For this purpose, the effect of drought stress through the irrigation cycle after 80 (control), 110 (mild stress), 140 (relatively severe stress) and 170 (severe stress) mm of evaporation from the class A evaporation pan on four grain sorghum cultivars, Sepideh, Kimia, Payam and KGS32, was investigated in summer cultivation in Khorramabad, Lorestan. The results showed that the amount of photosynthetic pigments (chlorophyll a, chlorophyll b and total chlorophyll, ratio of chlorophyll a/b, carotene and xanthophyll) and the amount of starch, protein, sodium and the ratio of sodium to potassium decreased with the intensification of drought stress, but the amount of nitrate, proline and potassium increased in the sorghum shoot. Intensification of drought stress was accompanied by the suppression of catalase, which caused the antioxidant defense mechanism to work through increasing peroxidase production. The highest amounts of non-structural soluble sugars, peroxidase and proline in the aerial part were obtained from KGS23 and Payam cultivars under severe drought stress conditions, while the highest amount of starch under normal irrigation conditions was obtained from the Sepideh variety, as were the highest amounts of catalase and total protein in the aerial part under normal conditions. Watering was observed in Payam and KGS23 cultivars. The trend of grain yield changes of all grain sorghum cultivars under the influence of drought stress followed a significant and negative linear relationship, but the changes of peroxidase and proline with increasing drought stress had a significant and positive linear relationship. In general, grain sorghum cultivars KGS23 and Sepideh have different drought stress tolerance mechanisms and can be recommended for normal and stressful conditions in the temperate region of Khorramabad.

Alzheimer's is the most common age-related neurodegenerative disease, characterized by amyloid plaques and intraneuronal neurofibrillary tangles. Nowadays, researchers are considering the use of nanoparticles in the treatment of skin diseases, various injuries and burns, bacterial and fungal infections, and digestive diseases. This research aims to biosynthesis of gold nanoparticles using Bacillus cereus PTCC 1015 and investigate their antioxidant and anti-amyloid effects on bovine serum albumin as a model protein. The properties of the synthesized nanoparticles were investigated using UV-vis, FTIR, XRD, TEM, SEM and EDX analyses.  The antioxidant and anti-amyloid activities of the synthesized nanoparticles were also evaluated using DPPH and Congo red tests, respectively. Based on electron microscopy images, the synthesized nanoparticles had a spherical morphology with sizes ranging from 20 to 70 nm. The DPPH assay results showed that the synthesized nanoparticles effectively inhibited DPPH free radicals in a concentration-dependent manner, with an IC50 value of 0.8 μg/ml. Furthermore, the anti-amyloid activity results showed that the synthesized nanoparticles have significant potential to inhibit  amyloid fibrils, and the highest percentage of inhibition was observed at a concentration of 3.2 μg/ml. The present study demonstrated that B. cereus PTCC 1015 is an effective option for the synthesis of gold nanoparticles. Considering the antioxidant and anti-amyloid activities of the synthesized gold nanoparticles, this study represents an important step for further in vivo research.