Showing 7 results for Steroid
Volume 2, Issue 2 (6-2013)
Abstract
Plant extracts, like phytoecdysteroids, are currently studied because of the possibility of their use in plant protection. Phytoecdysteroids are insect steroid hormone analogues, and they are believed to deter invertebrates from plants, either by acting as antifeedants or by being toxic through hormonal disruption on ingestion. We describe here the effects of extract from Spinacia oleracea L. (Chenopodiaceae), a plant producing phytoecdysteroids, on the demographic parameters of Plutella xylostella L. (Lepidoptera: Plutellidae). Spinach is one of the very few crop plants which produce large amounts of phytoecdysteroids. Ecdysteroidal extracts of leaves from this plant were incorporated into food given to third instar larvae for two days. Then the larvae were reared on untreated leaves. The eggs from the emerging adults were picked up for demographic experiments. The rearing of the newly hatched larvae was continued individually on untreated leaves. All experiments were performed on 25 ± 1 ºC, 65 ± 5% RH and a photoperiod of 16:8 (L: D) hours in a growth chamber. Data analysis demonstrated that the fecundity of the females was strongly affected by ecdysteroidal extract. Values of intrinsic rate of increase and net reproduction rate decreased significantly as concentration of the extract increased. However, doubling time increased significantly as concentration of the extract increased. The present study demonstrated that the ecdysteroidal components of the spinach are effective on the demographic parameters of P. xylostella. Therefore, this extract may be potential protectants as botanical alternative agent.
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Volume 5, Issue 3 (12-2016)
Abstract
The effect of ovulation inducing LHRH-A2 on sex steroids levels, stress indices and plasma biochemical parameters of the female sterlet, Acipencer ruthenus, were determined. The fish were injected intramuscularly with 10 μg/kg of LHRH-A2 in two phases of in 10 and 90% at 12 hours interval. Blood samples were collected before injection (control), 12 hours after the first injection, and after the ovulation. Significant differences in the levels of testosterone (T), glucose and aspartate amino transferase (AST) concentrations were observed at the three samplings (P<0.05), but the levels of progesterone (P), 17β estradiol (E2), cortisol, alanine amino transferase (ALT), and total lipid did not change significantly (P>0.05). This study demonstrated that the injection of LHRH-A2 has influence on liver enzymes activities and some hormones involved in final oocyte maturation. The results revealed that injection of LHRH-A2 had little impact on stress indicators, but some sex steroids such as T and blood biochemical parameters particularly AST were affected by hormonal induction.
Z. Ghaderi , B. Falahatkar, H. Allaf Noveirian , A. Rahdari ,
Volume 8, Issue 1 (3-2019)
Abstract
The aim of the present study was to investigate the effects of ascorbic acid and density on reproductive performance and steroid hormones in rainbow trout (Oncorhynchus mykiss). In this regard, six treatments were considered included three diets containing 0, 100, and 1000mg ascorbic acid as L-ascorbyl-2-polyphosphate per kilogram of food in contrast to two densities 4.33kg/m3 and 2.16kg/m3. Triplicate groups of fish were fed one of the test diets for 16 weeks. A total of 81 females with an average weight of 812.1±1.5g were introduced to tanks (910 liters). At the end of the 16th week and when preparing fish for spawning, from each replication of high and low densities, 4 and 2 fish after bleeding of fish to measure the concentrations of progesterone, testosterone, and estradiol were spawned. After that, reproductive parameters such as work fecundity, ova per gram, and ova diameter were measured and then fertilized. During the incubation period, fertilization and mortality rates were recorded. The results showed the interaction between ascorbic acid and density and also the significance of this effect in reproductive parameters (number per gram of egg, oocyte diameter, coagulation, and fertilization percent; p<0.05). In the case of steroid hormones, the effect of treatments on the amount of each of the three hormones and their interaction on the level of estradiol and testosterone were significant (p<0.05), but the effect of density and diet on progesterone was not significant (p>0.05). The results of this study confirm the use of higher levels of ascorbic acid in breeders compared to grow-out period and also the positive role of this vitamin in reproductive indices.
Volume 8, Issue 2 (2-2019)
Abstract
The cotton bollworm, Helicoverpa armigera (Hübner) is an important pest of many crops. Here, effects of kaempferol on ecdysteroid titer in the ovaries, hemolymph andoocyte size via tachykinin-4 content of H.armigera were studied. Third instar larvae of H. armigera were fed on artificial diet containing different concentrations of kaempferol for 8 days. Kaempferol had insecticidal activity after 6 days. The highest level of larval mortality was approximately 36% in larvae fed diet containing 10µg/g of kaempferol for 8 days. Competitive ELISA showed that tachykinin-4 titer decreased clearly in the adult female moth's brain and hemolymph which fed on diet containing 5 and10µg/g kaempferol during their larval stage for 8 days. It also decreased ecdysteroid in the ovary and hemolymph of adult female. Moreover, oocyte size was significantly decreased. On the other hand, the injection of tachykinin-4 into the hemocoel not only increased ecdysteroid titer in the ovary but also approximately 1.4 fold increases in oocyte size was observed. In conclusion, feeding on food containing kaempferol decreased tachykinin-4 level in the brain and hemolymph that itself led to decreasing ecdysteroid titer in the ovary and hemolymph. Finally the decrease in ecdysteroid titer resulted in smaller oocytes.
Volume 11, Issue 2 (7-2022)
Abstract
The present study investigated the effect of allatostatin (Ast) on the adult female reproductive system of the greater wax moth, Galleria mellonella (L.). At first, different concentrations of Ast in the brain- SOG, midgut, ovaries, and fat body of 5 days old adult females were confirmed. Moreover, it was shown that the highest concentration of Ast was observed in brain-SOG. Daily injections of Ast decreased ecdysteroid concentration in the hemolymph and ovaries. Ast injection decreased the expression level of vitellogenin (Vg) genes. Furthermore, it reduced oocyte size. These results showed that Ast has a regulatory role in the reproduction of G. mellonella female.
Volume 12, Issue 3 (9-2009)
Abstract
Objective: RNA interference (RNAi) is the most potent technique for gene silencing in eukaryotic cellular system at transcriptomic level. Genetic disorders and cancers are important targets for therapeutic development of this technique. In order to bypass the temporary dpwnregulation by siRNA, a new generation of shRNA named shRNAmir has developed. Silencing construct with structure similar to microRNA (shRNAmir), mimics a natural microRNA pathway inside the cell. Steroid receptor RNA activator (SRA) is one of the regulators of steroid receptor like ER. Prostate, uterus and breast tissue express a low level of SRA, there is an increase of expression during their tumorgenesis. So SRA may participate in tumorgenesis or proliferation of tumors.
Materials and Methods: We used RNAi technique to silence expression of SRA. The SRA silencer was designed and constructed by Soe-PCR, then cloned into an expression vector pEGFPC1. Human breast cancer (MCF7) cells were transfected with silencer plasmid then the changes in the SRA expression estimated by Real-Time PCR at 24, 72 hours and after 10days.
Result: The results showed about 60% decrease in relative expression of SRA gene, after 72 hours and 10 days, which shows that shRNAmir–SRA could successfully knockdown the expression of target gene.
Conclusion: It seems that the designed shRNAmir may be a suitable tool for a variety of applications because it could stably knockdown the expression of target gene.
Tahereh Dordab, Iman Sourinejad, Melika Nazemi, Zahra Ghasemi,
Volume 12, Issue 3 (9-2023)
Abstract
The present study aimed to isolate the steroids and fatty acids from the liver of the Persian Gulf spot tail shark Carcharhinus sorrah and to assess their antifungal activity. Extraction was done by methanol 70% and then, the lipids were separated through column chromatography with silica gel. Identification of the extracted lipids was done by thin layer chromatography and gas chromatography coupled with mass spectrometry. Then, antifungal activity of the steroids was investigated through determining the minimum inhibition concentration and minimum fungicidal concentration by tubular dilution method against Aspergillus fumigatus and Candida albicans. Identification of the extracted compounds by GC-MS confirmed the presence of these steroids in the shark liver. The identified steroids included compounds of Y-Sitosterol, Desmosterol and Squalene, which showed different results regarding the growth inhibition and fungicidal effects against the microorganisms at different experimental doses. Desmosterol and Squalene at minimum concentration induced the highest inhibitory effect on the fungus but Y-Sitosterol induced the highest inhibitory effect on the yeast. Squalene showed fungicidal effect only on the fungus and totally, A. fumigatus was more sensitive to the antimicrobial activity of the liver compounds than C. albicans. In conclusion, promising results were found regarding the antimicrobial activity of the lipid compounds derived from Persian Gulf shark liver, revealing the importance of more comprehensive investigations of these natural compounds for the synthesis of biomedicines from the marine organisms.
