Boron induces early matrix mineralization via calcium deposition and elevation of alkaline phosphatase activity in differentiated rat bone marrow mesenchymal stem cells

Objective: Boron [B] is essential for plant development and might be an essential micronutrient for animals and humans. This study was conducted to characterize the impact of boric acid [BA] on the cellular and molecular nature of differentiated rat bone marrow mesenchymal stem cells [BMSCs]

Materials and Methods: In this experimental study, BMSCs were extracted and expanded to the 3rd passage, then cultured in Dulbecco's Modified Eagle's Medium [DMEM] complemented with osteogenic media as well as 6 ng/ml and 6 µg/ml of BA. After 5, 10, 15 and 21 days the viability and the level of mineralization was determined using MTT assay and alizarin red respectively. In addition, the morphology, nuclear diameter and cytoplasmic area of the cells were studied with the help of fluorescent dye. The concentration of calcium, activity of alanine transaminase [ALT], aspartate transaminase [AST], lactate dehydrogenase [LDH] and alkaline phosphatase [ALP] as well as sodium and potassium levels were also evaluated using commercial kits and a flame photometer respectively

Results: Although 6 microg/ml of BA was found to be toxic, a concentration of 6 ng/ml increased the osteogenic ability of the cell significantly throughout the treatment. In addition it was observed that B treatment caused the early induction of matrix mineralization compared to controls

Conclusion: Although more investigation is required, we suggest the prescription of a very low concentration of B in the form of BA or foods containing BA, in groups at high risk of osteoporosis or in the case of bone fracture

Low dose and long term toxicity of sodium arsenite caused caspase dependent apoptosis based on morphology and biochemical character

Although arsenite is toxic it is currently recommended for the treatment of malignancies. In this study the effects of sub-micromolar concentrations of sodium arsenite on the viability, morphology and mechanism of cell death of rat bone marrow mesenchymal stem cells [BMCs] over 21 days was investigated. In this experimental study, BMCs were extracted in Dulbecco's Modified Eagles Medium [DMEM] containing 15% of fetal bovine serum [FBS] and expanded till the 3rd passage. The cells were treated with 1, 10, 25, 50, 75 and 100 nM of sodium arsenite for 21 days and the viability of the cells estimated using 3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium [MTT] and trypan blue staining. Cells were then treated with the selected dose [25 nM] of sodium arsenite to determine their colony forming ability [CFA] and population doubling number [PDN]. Morphology of the cells was studied using florescent dyes, and the integrity of the DNA was investigated using the comet assay and agarose gel electrophoresis. The terminal deoxynucleotidyl transferase dUTP nick end labeling [TUNEL] and the caspase 3 assay were then applied to understand the mechanism of cell death. Data was analyzed using one way ANOVA, Tukey test. A significant reduction of viability, PDN and CFA was found following treatment of BMCs with 25 nM sodium arsenite [p<0.05]. Cytoplasm shrinkage and a significant decrease in the diameter of the nuclei were also seen. Comet assay and agarose gel electrophoresis revealed DNA breakage, while positive TUNEL and activated caspase 3 confirmed the apoptosis. A low concentration of sodium arsenite [25 nM] caused reduction of viability due to induction of apoptosis. Therefore, long term exposure to low dose of this chemical may have unwanted effects on BMCs

Effects of vitamin E on ovarian tissue of rats following treatment with p-nonylphenol: a stereological study

Para-Nonylphenol [p-NP] is one of the environmental pollutants which cause reproductive system disorders. The effects of vitamin E on ovary structure during its development in rats treated with p-NP. 32 Wistar female rats after mating were divided into 4 groups; control, vitamin E [100mg/kg/day], p-NP [250mg/kg/day] and p-NP + vitamin E. The rats were treated from the day 7 of pregnancy till 21st day of postnatal through sucking period. After weaning, the female pups were treated by gavages for 120 days. The total volume of ovary, number of follicles, volume of oocyte, follicular cells and their nuclei and the thickness of zona pellucida were estimated stereologically. The results were analyzed using one way ANOVA and p<0.05 was considered significant. The ovary weight, mean total volume of ovary and cortex, number of antral and graafian follicles and body weight were decreased significantly [p<0.05] in the p-NP treated rats compared to control and other groups, while the number of atretic follicles was increased significantly [p<0.05]. A significant reduction [p<0.05] in volume of oocyte, follicular cells and their nuclei in antral and graafian follicles was found in p-NP group. In addition, treatment with only vitamin E showed an improving effect on folliculogenesis due to a highly significant increase [p<0.01] in the number of primordial follicles. Vitamin E could compensate the adverse effects of p-NP on the ovary structure during its development