نشریه یافته های نوین در علوم زیستی
سال هشتم شماره 2 (پیاپی 28، تابستان 1400)

The aim of this study was to investigate the interaction modification of curcumin complex molecule (CUR) in beta- and gamma-cyclodextrin (β-CD and γ-CD) carriers with chitosan (CS) nanoparticles for targeted drug delivery and to compare their performance. The targeted drug delivery system includes the therapeutic agent of the CS nanoparticles targeting section of the same drug and the CD carrier system. Calculations of the relationships of the formation of modified complexes and their application were performed using UV-vis spectroscopic data analysis. In this study, spectroscopic spectrum diagrams were drawn to prove the optimization of molecular structure in the modified complexes. Data analysis was performed using their respective equations. The cationic polysaccharide CS, with the presence of amino agents and alcohols along the polysaccharide chains, enables it to form a covalent bond with the complexes and increase the solubility of cyclodextrin. CS nanoparticles strengthen the hydrogen bond by hydrogen bonding and van der Waals hydrogen interactions of the hydroxyl cyclodextrin group with the hydroxyl phenolic group of the drug molecule CUR. Modification of the γ-CD complex with CS shows the strongest interaction with CUR. Both CUR complexes are in the CD-CS host system to transfer the charge from the drug to the carrier and the therapeutic agent. CS nanoparticles have the property of targeted delivery systems for anticancer drugs because the CS external field can be used to direct the drug to specific target cells. The γ-CD-CS host system is the best host as a carrier and therapeutic agent for CUR due to its high solubility and strong interaction.

Regarding the rising rate of esophageal cancer in some parts of Asia, including northern and northeastern regions of Iran, the identification of new anti-cancer compounds is essential to combat the disease. The relation between some plants metabolites and these endophytic microorganisms are well characterized. In the current study, the potentials of Ephedra endophyte bacteria for the inhibition of esophageal cancer cell line (KYSE-30) proliferation were investigated. A total of 54 endophyte bacteria (out of 70) were obtained from the sterilized surfaces of two medicinal plants, i.e., Ephedra intermedia and Ephedra foliata. Bacterial strains were then cultured in Tryptic soy broth (TSB) medium and, after 72 h incubation, the produced secondary metabolites were extracted by chloroform. Anticancer effects of secondary metabolites from theses bacteria on esophageal cancer cell line KYSE-30 were evaluated after 24, 48 and 72 h by MTT method. MTT assay results showed that only strain A1 had a cytotoxic effect on KYSE-30 cells. The IC50 amounts of this strain against KYSE-30 cell lines were equaled (µg/ml) to 346.4, 192.8 and 121.3 after 24, 48, and 72 hours, respectively. The molecular identification of strain A1 revealed that Microbacterium maritypicum (99.8% similarity) was the closest identified taxon to the strain studied. According to the promising ability of strain A1 to inhibit the growth of KYSE-30 cell line, the use of natural compounds produced by this bacterium to treat esophageal cancer was found to be applicable. However, more experiments are needed to confirm these results after purifying the ingredients, as well as conducting studies in animal cancer models.

Salinity stress is an important challenge for wheat production in the world. Plant growth promoting rhizosphere bacteria, isolated from halophytic plants, can increase the tolerance of crop plants to salinity by direct and indirect mechanisms. In this study, plant growth-promoting traits of bacterial strains (Bacillus safensis, Bacillus pumilus and Zhihengliuella halotolerans), isolated from the rhizosphere of several halophyte plants, were deterimined and their effects on some vegetative traits and ionic content of wheat plant irrigated with saline water ( 0.2, as control,  4, 8 and 16 dS/m) were measured. Result showed that all three bacteria were able to produce auxin, hydrogen cyanide, siderophore, 1-aminocyclopropane-1-carboxylic acid deaminase and soluble phosphate. The increase in salinity levels caused increase in the concentration of sodium and decrease in the concentration of potassium, calcium and phosphorus in wheat leaves, as well as decrease in stem length, shoot and root dry weight, root to shoot dry weight ratio and total biomass. In wheat plants irrigated with saline water and inoculated with the bacterial strains, sodium concentration decreased up to 17.7% and concentrations of potassium, calcium, phosphorus and potassium to sodium ratio increased up to 33, 25.7, 200.4 and 41%, respectively. The most efficient bacterium was found to be Z. halotolerans. All bacterial isolates also increased stem length, shoot and root dry weight, root to shoot dry weight ratio and total biomass by 17, 58.6, 137, 88 and 66 %, respectively. The results of this study showed that the plant growth-promoting bacteria of rangeland halophytic plants potentionally improve the growth indices of wheat plants in saline conditions. These results also showed that the rhizosphere of halophytic plants in rangelands can be a good source for the isolation of salinity-resistant bacteria to improve the resistance of wheat plants to salinity.

One of the major abiotic stresses that negatively affects plants is the presence of heavy metals. Soil pollution with heavy metals, resulting from the industrial development and use of fertilizers containing heavy metals, has become a major environmental concern in human societies. Mercury is a toxic heavy metal that causes pollution in agricultural lands. Accumulation of Hg by plants may disrupt many cellular functions and block growth and development. Under such conditions, the enzymatic and non-enzymatic defense systems of plants are activated. Several defense systems are cooperating together in plants to cope with stressful situations. In this study, the effect of different concentrations of mercury on the photosynthetic pigments content and non-enzymatic defence systems in Nicotiana tabacum was studied. After planting the plants under the same conditions in the hydroponic medium and feeding the plants with Hoagland solution, treatments with different concentrations of mercury nitrate (0.5, 1 and 3 mM and a control group) were applied to the seedlings in three replications. Ten days after the application of the treatments, the plants were harvested and examined. The results showed that tobacco plants which had been exposed to heavy metal used the accumulation of osmolytes such as proline and soluble sugars in order to balance their osmotic pressure. The decrease in the amounts of photosynthetic pigments and increase in the levels of malondialdehyde in the leaves indicated the elevation of oxidative damage. Increased activity of non-enzymatic antioxidants in tobacco leaves, including anthocyanins, phenol, flavonols and flavonoids, can be interpreted as the mechanisms of resistance to heavy metal stress induced by mercury.

In order to investigate the effects of salinity and magnesium (Mg) on the growth parameters, physiological characteristics and content of some metabolites in Syrian bean-caper (Zygophyllum fabago) plants, a factorial experiment with completely randomized design was performed and carried out in perlite with Hoagland solution. The treatments were combinations of two levels of salinity (0 and 300 mM NaCl) and three levels of Mg concentration (2, 4 and 8 mM; 0, 2 and 6 mM over the standard Mg content of Hoagland medium, 2mM, respectively). The simultaneous effect of salinity and Mg did not change the fresh weight of the plants, but increased the dry weight by 50%. Salinity reduced the leaf area, but the presence of Mg improved and even increased the leaf area of the plants. The Mg reduced NAR, while increased LAR and RLGR. Salinity decreased the RLGR. The simultaneous effect of salinity and Mg increased and improved RGR, LWR, RLGR. The tolerance index in saline treatments increased with the presence of Mg, but the R/S ratio showed a significant increase only in salinity condition, however, the presence of Mg moderated it. Salinity reduced the photosynthetic pigments, while the presence of Mg ameliorated the decrease. As a result, salinity and Mg increased the total sugar content of the leaf and reduced the total sugar content of the root. Salinity and Mg reduced the total protein content of all the organs of the plant specimens studied. In general, salinity had a negative effect on the physiological parameters of the Zygophyllum fabago plants, while the application of supplementary Mg improved the growth indices and increased the plants tolerance against salinity.

Centaurea glastifolia, a plant species from the Asteraceae family, is distributed in the Northwest of Iran. This study carried out to determine suitable habitats and habitat connectivity of Centaurea glastifolia in three Provinces of West Azarbayejan, East Azarbayejan and Ardabil. Seven habitat variables and 36 presence points were selected for habitat modelling using six habitat distribution models of GLM, GAM, MARS, MaxEnt, RF and GBM. The ensemble map resulting from these models was used for habitat connectivity modelling using electrical-circuit method. Results of habitat evaluation revealed that suitable habitats of the species studied were mainly located in West Azarbayejan and east of Ardabil Provinces, for which distance from agricultural lands, mean annual temperature and distance from rangelands had the highest contribution to the model. Habitat connectivity modelling showed that the current density movement was highest in West Azarbayejan. Current density movement between East and Southeast of Ardabil was evaluated to be significant, whereas the current density movement between West Azarbayejan and Ardabil Provinces was relatively low. The high current density movement in West Azarbayejan indicates the species’ high dispersal ability in expanding its range across the area. The results of the current study could facilitate understanding of the distribution and dispersal of Centaurea glastifolia.

Distribution of rivers, pools and grasslands, being large or small and perennial or temporary, have created conditions suitable for the establishment of wetlands, especially in the highland regions of the Country. These habitats are highly important for the preservation of biodiversity and other ecological aspects. The present study aimed to identify wetlands in the Kermanshah Province, Iran, and map their distribution. The investigation was carried out on the basis of the conventional taxonomic studies of the region by doing field observation in 31 aqueous habitats in Kermanshah Province. The flora of each habitats and the life form and geographical distribution of the species were investigated. In total, 617 plant specimens, belonging to 288 species, 218 genera and 62 families, were collected identified and stored in the herbarium of the research center of agriculture and natural resources of Kermanshah Province (RANK). Asteraceae with 41 species, Poaceae with 31 species, Fabaceae with 31 species and Brassicaceae with 24 species were found to be the most important families of the wetlands studied.  Trifolium with 11 species and Bromus with 6 species were the most important genera, in terms of species richness. Detection of the biological forms showed that 40.3% of the species were trophytes, 35/5% were hemicryptophyts, 6/1% were phanerophytes, 14/23% were cryptophytes and 3/72% were chamaephytes. The chorology of species showed that 93 species belonged to more than two elements (32%), 92 species (31%) to the Irano-Touranin elements, 32 species to Irano-Touranin- Mediterranean (11%), 9 species to Irano-Touranin- Euro-Siberian with (3%) and 23 species were found to be cosmopolitan elements (8%).