نشریه زیست شناسی کاربردی
سال سی و پنجم شماره 4 (زمستان 1401)

This study aimed to isolate and identify the silver-resistant bacteria and investigation on their potential in the biological synthesis of silver sulfide nanoparticles (Ag2SNPs).

Preliminary characterization of the Ag2SNPs was carried out using visual observations and UV–Visible spectroscopy. Scanning Electron Microscopy (SEM) with Energy Dispersive X-Ray Analysis (EDX) was used to determine size, morphology, and elemental analysis of the nanoparticles. Fourier-transform infrared spectroscopy (FTIR) analysis was performed to determine the functional groups that are involved in the bioreduction of silver sulfate into Ag2SNPs.

Based on the results, Bacillus safensis strain GMS10 with highest tolerance to silver sulfate (50 mM) was able to synthesize spherical shape of Ag2SNPs with an average size diameter of 22.2 nm under optimized conditions (1 mM silver sulfate, 15 g/L biomass) after 36 hours incubation. This study is the first report on the synthesis of Ag2SNPs using B. safensis.

Ammi visnaga Lam. (Umbelliferae family) is one of the valuable indigenous medicinal plants in the country, which contains an active medicinal substance γ-Pyrones (mainly khellin and visnagin) and their most important therapeutic effects are peripheral and coronary vasodilator and bronchodilator and is used in the therapy of asthma and angina pectoris. In this research first, separation and purification khellin and visnagin from the extract sample were performed by column chromatography and recrystallization. Then they have been identified by thin layer chromatography, melting point and Fourier transform infrared spectroscopy. A high performance liquid chromatography has also been accomplished for their quantitative determination and degree of purity in the extract. As the results, isolated compounds from the extract (khellin & visnagin) were identified and verified by the similarity of melting points in the range of 153-155 ͦ C and 142-145 ͦ C respectively, their FTIR spectroscopy data, compared with the standard samples and determination of their Rf values (0.44 and 0.37, respectively). HPLC chromatograms of the extract (khellin & visnagin) displayed sharp, symmetrical peaks with high resolution at retention times of 8.617 and 10.55 min respectively. The mean contents of khellin and visnagin in the extract were 1.114 mg/g and 0.326 mg/g and purity of 90.16% and 79.62% respectively.Therefore, the produced γ-Pyrones (khellin and visnagin) had reasonable yield and high purity, therefore can be used for the pharmaceutical industry of Iran.

The Mediterranean flour moth, Ephestia kuehniella (Zeller), is one of the most important pests of stored products which causes a lot of damage. Considering the economic importance of stored product pests, such as the Mediterranean flour moth and their resistance to conventional chemical insecticides, finding a safe, suitable, economical and sustainable way to control and reduce the damage of these pests seems necessary. The use of plant essential oils is one of the suitable methods for controlling stored product pests, which has been considered in recent years. In this study the lethality effect of essential oils of Rosa hybrida, Citrus aurantium and Ixora chinensis were evaluated on the second, third and fourth instars larvae of E. kuehniella at laboratory conditions. The experiments were conducted at 27±2 °C, and 75±5% relative humidity under dark conditions. LC50 values of R. hybrida, C. aurantum and I. chinensis essential oils on the second, third and fourth instars larvae after 72 hours were »308.8, 658.7 and 636.9«, »446.7, 804.6 and 1183.3« and »1120.3, 2072.1 and 1761.7« μl.L-1 air, respectively. The lethality of the essential oils increased with increasing effect time. The results of this study showed that using of some plant essential oils could be an appropriate alternative to chemical compounds in stored product pest management.

Identification of flora of every region not only plays an important role in conserving of genetic resources of the region, but also provides useful data for other scientific researches. The goal of this study was to identify and introduce the flora of the mining area of Hamekasi in Hamadan province, located 2164 meter above sea levels.

Plant specimens were collected in 2017 during active growth form by field–walk procedure and identified using relevant flora sources. Then, determination of life forms, geographical distribution as well as the conservation status and percentage of native plants were carried out in the mining area of HameKasi. Life forms were determined using Raunkiaer method and the chorology is based on the vegetation regions classified by Zohary.

Based on the present results, a total of 68 genera and 79 species were recorded in the study area belonging to 26 families. Eudicots include 16 families while monocots consist of five families. Asteraceae, Poaceae and Lamiaceae were the most abundant families in the area, respectively. The predominant life forms included hemicryptophytes (52%) and therophytes (25%), respectively. The elements of Irano-Turanian region with 37 species (48%) have the highest geographical distribution of vegetation followed by European-Siberian/Irano-Turanian elements with 14 species (18%). According to the current assessment, 11 native, 9 medicinal and 10 low-risk species were identified. Due to human activities in the region, conservation policies should be seriously considered to preserve species richness and reduce the effects of destruction.

In addition to providing significant amounts of nutrients in our diet, plants reduce the risk of many diseases. The beneficial effects of their consumption are due to the presence of various antioxidant compounds such as vitamin C, polyphenols and flavonoids.

The antioxidant properties of fruits are directly related to the presence of these compounds in plants. For this purpose, a study was conducted to evaluate the biochemical and antioxidant quality of blood orange, kumquat and grapefruit. In this study, after random sampling of blood oranges of Moro, Kumquat and Grapefruit, various traits including protein content, vitamin C, anthocyanin, antioxidant capacity, catalase and peroxidase enzyme activity, polyphenols and flavonoid content were measured. The obtained data were analyzed using analysis of variance.

The results showed that the highest amount of protein, polyphenols and anthocyanin was found in blood orange fruit, the highest amount of vitamin C and peroxidase was related to kumquat and the highest amount of flavonoids, catalase activity and antioxidant capacity was obtained from grapefruit.

Although blood orange is a valuable fruit, but, the highest amount of vitamin C and peroxidase was related to kumquat and the highest antioxidant capacity was obtained from grapefruit.

Recombinant antibody technology has revolutionized the production and use of these kinds of antibodies and removed some of the hybridoma technology limitations. Monoclonal antibodies have high potential as diagnostic and therapeutic agents, especially in targeting cancer cells, but their use has been limited due to their large size. The special structure of different regions of antibodies allows to divide them into efficient subunits, which can combine to form new molecules with efficient properties. Due to the reduced size of scFv molecules compared to the primary antibody, they have many advantage. The most important of which is the reduction of immune compare to complete mouse antibodies due to the lack of constant fragments. In this study, the variable regions of gene carcinoembryonic tumor marker monoclonal antibody were constructed as scFV and cloned into the phagemid vector. Then its specificity was investigated by the western blotting test. The scFV gene was successfully constructed. Then cloning and expression was performed. Finally, its specificity was confirmed by western blotting. The recombinant scFV antibody expressed in this study, due to size change, was able to specifically identify the carcinoembryonic tumor marker, and therefore it can be used in the diagnosis of some cancers. This recombinant antibody was specifically capable of carcinoembryonic tumor marker recognition. Therefore, it can be applied to some cancers diagnosis and monitoring. In addition, this method can be used to synthesize scFV-type recombinant antibodies against other antigens. So that they can be used in various diagnostic tests and treatment most of diseases.

The positive potential of brassinosteroids and polyamines as protective agents for environmental stresses has been proven.

In this study, Cucurbita pepo was pretreated with 24-epibrasinolide (EBL) (0, 0.01 and 0.1 μM) and spermine (0, 0.1 and 1 mM) and then salinity treatment (0, 40 and 80 mM sodium chloride) was applied.

Salinity stress decreased dry weight, potassium and calcium content and increased sodium content. EBL and Spm increased potassium, calcium and decreased sodium in shoots. Salinity stress increased root SOS1 gene expression and had no effect on NHX1 gene expression. EBL and Spm decreased expression of SOS1 gene while Spm increased expression of NHX1 gene. Therefore, it seems that Spm via the over-expression of the NHX1 gene substantially increased the tolerance to stress by sequestering excess Na+ into the vacuoles and sustaining a better cellular environment for improvement of plant growth under salinity stress.

Breast cancer has the highest cancer incidence in women. The cytotoxic activity of Berberis vulgaris fruit extract on MCF-7 cancer cells was investigated for the first time in this study.

In this experimental study, MCF-7 cancer cells were incubated in different concentrations of barberry fruit extract (31.25, 62.5, 125, 250, 500, 1000, and 2000 μg/ml) for 24 hours, and the cytotoxicity level with the MTT method, apoptosis by flow cytometry method using the annexin V/FITC/PI kit, morphological changes by fluorescence microscopy using Hoechst dye, expression of TP53 and MDM4 genes by real-time PCR method, and the activity of caspases 3 and 8 and 9 were analyzed by the colorimetric method. The interpretation of the results was made with a one-way analysis of variance. P < 0.05 was reported as significant.

The effect of barberry fruit extract on MCF-7 cells was dose-dependent, and the highest effect of the extract occurred at a concentration of 2000 μg/ml in 24 hours (IC50 = 1681 μg/ml). The results showed that the relative expression of P53 and MDM4 genes increased significantly compared to the control group (untreated) (P<0.001). The percentage of apoptotic cells increased more than 81 times compared to the control group (untreated) (P<0.001). The activity of caspases 3 and 8, and 9 increased in treated MCF-7 cells (P<0.001).

Barberry fruit extract in specific doses reduces cell growth and increases the induction of apoptosis in MCF-7 cancer cells. Barberry fruit extract has anti-cancer properties in breast cancer treatment.

Biomimetic means imitating models, systems, and elements of nature to solve complex human problems. This field of science has led to the creation of new technologies inspired by biological solutions in macro and nano sizes. Thousands of people die every year due to diseases caused by antibiotic resistance. Therefore, the use of antimicrobial peptides has become particularly important.

in this study, branched polyethyleneimine polymer has been used as a biomimetic polymer of antibacterial peptides. In order to increase the antibacterial properties, the amino acids valine and lysine were used to modify the surface of branched polyethyleneimine. 1 H-NMR and FTIR were used to prove the binding of amino acids to the polymer. Antibacterial activity of the modified polymer by two methods of MIC test and growth inhibition zone on gram-positive bacteria S. aureus and B. subtilis and gram-negative bacteria E. coli and P. aeruginosa were examined.

Under optimal conditions, the concentration of branched polyethyleneimine polymer was 8 μl, and the amino acid valine to lysine ratio was 1: 6. Polyethyleneimine polymer modified with the amino acids valine and lysine inhibited bacterial growth concentration-dependent (p <0.05). 5 mg/ml of this polymer inhibits the growth of bacteria by more than 70%. The diameter of the inhibition zone of this polymer in examined bacteria reached about 15-20 mm. The antibacterial activity of this polymer was comparable to that of the antibiotic cefepime. It seems that this polymer can be used as an antibacterial polymer.

The use of herbal compounds with antioxidant properties can be used as an important strategy to reduce inflammatory diseases by reducing oxidative stress. The aim of this study was to investigate the antioxidant and anti-inflammatory effects of methanolic and hydroalcoholic extracts of this plant on the inhibition of albumin denaturation as well as the inhibition of erythrocyte hemolysis.

In this study, methanol and hydroalcoholic extract of Scrophularia striata were prepared and total phenol and flavonoids were calculated spectrophotometrically. The antioxidant activity of the plant extracts at different concentrations )25, 50, 100, 200, 400, 600 µg/ml) was investigated by DPPH method. In protein denaturation inhibition, 1% bovine serum albumin was added to different concentrations of the extract and after heating the percentage of inhibition for albumin denaturation was calculated. In the RBC membrane immobilization assay, to non-clot RBC, different concentrations of the extract were added and after heating the percentage of hemolysis inhibition was calculated.

The results showed that the amount of phenol and flavonoid in each extract was different and the methanolic extract of Scrophularia striata was higher. IC50 of methanolic extract of Scrophularia striata with DPPH test equals 312.4 µg/ml, anti-inflammatory protein denaturation inhibition test, 393.2 µg/ml and anti-inflammatory erythrocyte membrane immobilization test 502.52 µg/ml, which are lower than the IC50 of thirsty hydroalcoholic extract. In addition, there is a direct relationship between antioxidant and anti-inflammatory and extract doses.