Journal of Cell and Molecular Research

12-18

Authors: Narjes Zamani, Manijeh Mianabadi and Ahmad Abdolzadeh

Antioxidant activities protect the cell against oxidative agents that are constant metabolic by-products. The aim of this study was to investigate the relationship between harvesting time of Thymus transcaspicus and its antioxidant activities. The plant samples were harvested 5 times in different growth phases from 17 April to 22 July 2008, and its antioxidant activity was studied using the ferric reducing antioxidant power (FRAP), 1,1- diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, and β-carotene bleaching (BCB) assays. The results of FRAP assay indicated that the reduction activity of the plant was in the highest level in stage 5 of sampling. The result of DPPH assay showed that the crude extract of the plant was more capable of DPPH radical scavenging in stage 2. The highest level of gallic acid and quercetin in the crude extract of T. transcaspicus was determined as 85.29 ± 6.22 mg and 18.88 ± 0.9 mg in stage 2, respectively. Therefore, stage 2 was the optimum time to harvest the T. transcaspicus.

25-31

Authors: Zahra Mahmoudi, Maryam Moghaddam Matin, Morvarid Saeinasab, Saeideh Nakhaei-Rad, Mahdi Mirahmadi, Nasser Mahdavi Shahri, Mahmoud Mahmoudi and Ahmad Reza Bahrami

Regeneration is a biological phenomenon, which takes place via two main mechanisms: first, dedifferentiation of mature cells followed by their differentiation into functional new cells and second, activation of endogenous somatic stem cells for regeneration of damaged or lost tissues. One of the best examples of healing process in mammals is the regeneration of damaged pinna in rabbits by blastema tissue. The aim of present study was to investigate culture requirements, proliferative properties and expression of some stemness factors in cells derived from regenerating blastema tissue obtained from rabbit pinna in vitro. The regenerating tissues were obtained from male New Zealand white rabbits by double punching of the pinna and cell culture conditions were set to derive and enrich the self renewing cells for further characterisation. The cells were subjected to survival and growth examinations in vitro, and expression of several stemness factors was studied in these cells using reverse transcription polymerase chain reaction (RT-PCR). Results revealed that the derived cells are rather immortal, as they have been growing for more than 120 passages in culture up until this report. Furthermore, RT-PCR and flow cytometry analyses showed that these cells express a number of stemness related genes including Oct4 and Sox2. In conclusion, in this study, stem like cells were derived from blastema tissue of rabbit ears for the first time, showing great self renewing capacity, which provides a suitable in vitro model for regeneration studies. Moreover, they could be considered as a good source of stem like cells for future applications.

38-42

Authors: Mohammad Reza Nikravesh, Mehdi Jalali, Abbas Ali Moeen, Shabnam Mohammadi and Mohammad Hasan Karimfar

Nicotine is an alkaloid by high level of addictive property that can quickly assimilate from smoker’s lung. It passes from the placenta and gathers in the developing fetus. Our previous study showed that collagen type IV plays a critical role in basement membrane of different embryonic organs. In this study the effect of maternal nicotine was evaluated by collagen IV changes in lung of mice offspring during pre and postnatal period. Pregnant Balb/C mice were divided into 2 experimental and 2 control groups. Experimental group 1 received 3 mg/kg nicotine intrapritoneally from day 5 of gestation to last day of pregnancy. Experimental group 2 received the same amount of nicotine during the same gestational days as well as 2 first week after birth. The control groups received the same volume of normal saline during the same periods. At the end of exposure times, all newborns were anesthetized and their lungs were removed and immunohistochemical study for tracing collagen was carried out. Our results showed that collagen reaction in the bronchial basement membrane (BBM) and extra cellular matrix (ECM) of the lung parenchyma experienced a remarkable increase when compared to the control ones. Cell necrosis definition in lung parenchyma of the experimental group 2 was the other finding that our investigation revealed. These data indicate that maternal nicotine exposure may induce a noticeable collagen increase with a reasonable amount in BBM and ECM of respiratory system of next generation.