Investigation of cytotoxic activity in four stachys species from Iran

The aerial parts of Stachys laxa Boiss. and Buhse. from Siah-bishe in Mazandaran province, Stachys trinervis Aitch. and Hemsl. from Karaj in Alborz province, Stachys subaphylla Rech. F. and Stachys turcomanica Trautv. from Golestan province have been collected in May 2008. Total extracts were obtained through MeOH/H[2]O [80/20] and then partitioned between CHCl[3], EtOAc and MeOH. These fractions and total extracts have been investigated for in-vitro cytotoxic activity against the colon carcinoma [HT-29], colorectal adenocarcinoma [Caco-2], breast ductal carcinoma [T47D] and Swiss mouse embryo fibroblast [NIH 3T3] cell lines using MTT assay [3-[4,5-di methyl thiazol-2-yl]-2,5-di phenyltetrazolium bromide]. At each cell line, doses of 3.125, 6.25, 12.5, 25, 100, 200, 400 and 800 microg/mL in 1% [v/v] DMSO of all samples were tested. Ethyl acetate and chloroform fractions of Stachys laxa against proliferation of T47D and HT-29 cell lines and chloroform fraction of Stachys subaphylla and Stachys subaphylla ethyl acetate fraction toward T47D cell line exhibited highest cytotoxic activity [IC[50] < 50 microg/mL]. Ethyl acetate and chloroform fractions of Stachys turcomanica against HT-29 cell line, except methanol fraction of Stachys subaphylla, the other extrcts on T47D cell line, represented moderate cytotoxic activity [IC[50] < 70 microg/mL]. All fractions of S. trinervis demonstrated no effective cytotoxic activity. IC[50] values confirmed that the growth and proliferation of HT-29 and T47D cells were most affected by chloroform and ethyl acetate fractions of Stachys laxa and Stachys turcomanica due to their nonpolar compounds

Cytotoxic activities of silver nanoparticles and silver ions in parent and tamoxifen-resistant T47D human breast cancer cells and their combination effects with tamoxifen against resistant cells

Studies on biomedical applications of nanoparticles are growing with a rapid pace. In medicine, nanoparticles may be the solution for multi-drug-resistance which is still a major drawback in chemotherapy of cancer. In the present study, we investigated the potential cytotoxic effect of silver nanoparticles [Ag NPs] and silver ions [Ag[+]] in both parent and tamoxifen-resistant T47D cells in presence and absence of tamoxifen. Ag NPs were synthesized [< 28 nm] and MTT assay was carried out. The associated IC[50] values were found to be: 6.31 micro g/ml for Ag NPs/parent cells, 37.06 micro g/ml for Ag NPs/tamoxifen-resistant cells, 33.06 micro g/ml for Ag[+]/parent cells and 10.10 micro g/ml for Ag[+]/resistant cells. As a separate experiment, the effect of subinhibitory concentrations of Ag NPs and Ag[+] on the proliferation of tamoxifen-resistant cells was evaluated at non-toxic concentrations of tamoxifen. Our results suggested that in noncytotoxic concentrations of silver nanomaterials and tamoxifen, the combinations of Ag[+]-tamoxifen and Ag NPs-tamoxifen are still cytotoxic. This finding may be of great potential benefit in chemotherapy of breast cancer; since much lower doses of tamoxifen may be needed to produce the same cytotoxic effect and side effects will be reduced

Cross-resistance to vincristin and etoposide in a sub line of the human breast cancer T47D cells selected for adriamycin-resistance

Breast cancer is one of the most common malignancies among women. Although chemotherapy remains a major therapeutic approach to treat cancers, drug therapy often fails for several reasons, particularly the drug resistance. Resistance to multiple chemotherapeutic agents is one of the most important problems in the treatment of different types of cancers. Therefore, in this study a resistant sub line of the human breast cancer T47D cells was isolated in vitro by stepwise exposure to increasing concentrations of Adriamycin [ADR] to compare the characteristics of parent and resistant cells. We also evaluated the phenomenon of cross-resistance to some other chemotherapeutic drugs. A significant increase in doubling time of resistant cells, named T47D/ADR, [94 h] was observed when compared to the parental T47D cells [50 h] that indicates a relatively slow growth rate pattern of these cells. T47D/ADR cells were 4 fold resistant to adriamycin and also showed cross-resistance to vincristin [VCR, 3.5 fold] and to etoposide [VP-16, 5.5 fold] when compared to parent cells. Therefore, our results indicate that T47D/ADR cells are also cross-resistant to structurally and functionally different chemotherapeutic agents and can be used as a model for studying molecular changes of drug resistance

Humoral and cellular immunomodulation induced by propoxure in C57-w/6 mice

Propoxure [PPX] is a well-known carbamate insecticide, which has been used for several decades in the world and Iran in agriculture and public health programs. However, there is no clear investigation toward its immunotoxicity as yet. In this study, we examined the effects of subchronic i.p. exposure of PPX on humoral [PFC and HA] and cellular [DTH] responses, and also monitored T-Cell subtypes using FACS technique. Briefly, female C57b1/6 inbred mice were administered PPX [0.2, 2 and 10 mg/kg/day i.p. [5 inj/wk] for 28 days] or positive and negative controls. On the day 28, mice were examined for DTH, PFC and HA responses to SRBC. Splenocyte single cell suspension was used for measuring the spleen CD4/CD8 percentage and absolute number. In vitro lymphocyte proliferation response to non-specific antigen [PHA] was also measured using MTT method. Results showed that PPX at 10 mg/kg/day could suppress DTH response and could increase the spleen CD4-/CD8+ T-cell percentage. On the other hand, PPX at medium dose [2 mg/kg] could increase the antibody formation response against SRBC as determined by PFC and HA. Subchronic PPX at low dose [0.2 mg/kg/day] could not show any significant effects on humoral or cellular responses. It could be concluded that, subchronic PPX at high dose [10 mg/kg], possessed cellular immunosuppressive effect. However, PPX at 2 mg/kg does not change cellular response to antigen but can stimulate humoral responses. It seems that PPX has no adverse effects on mice immune system at low doses as 0.2 mg/kg, which is 10 fold greater than PPX Allowed Daily Intake limit

blood pressure and dermal sensitivity effects of nylon hollow fibre releasing glycerin trinitrate in vivo

In order to improve patient's compliance in taking glycerine trinitrate [GTN] nylon hollow fiber which has been successfully used for release of chlorhexidine diacetate and levonorgestrel was employed to make nylon hollow fiber releasing GTN. Hollow nylon fibres of external diameter 0.63 mm, 75 mm long with an internal capacity of 16 micro l, were filled with GTN [190 mg/ml] in 70% ethanol [v/v] or vehicle alone and the ends were heat-sealed. The fibers were then immersed in 10 ml of 0.9% [w/v] saline in a separating funnel. The GTN release pattern from fiber, the effect of the product on blood pressure and its potential dermal toxicity were assessed. The release of GTN from the fibres was approximately 2.7 micro g/min when the fibres contained 16 mg of drug. The results showed that the amount of GTN within the single fibre was enough to reduce blood pressure significantly, while it did not show significant dermal toxicity. It is concluded that GTN fiber, if used as monofilament, is not an alternative method for GTN delivery

study of teratogenic effect of cyclosporine in vitro

The use of immunosuppressive medication such as Azathioprine, methoterxate and mercaptopurine in treatment of rheumatic disease in women at childbearing age has some risks of teratogeniesis. Cyclosporine is one of the newer medicines, which has been introduced for this disease but little is known about its teratogenicity. This study was designed to investigate the possible teratogenicity of this drug by using cultured rat limb bud cells, which were obtained from rat embryos 13 days after conception. Cells were incubated in trypsin-EDTA solution for 30 min at 37°C and then filtered through 50 micro m nylon filters. The resultant cell suspension was cultivated in 1 ml Dulbecco modified Eagle medium [DMEM] containing 10% fetal bovine serum and 445 micro g/L L-glutamine at 37°C with 5% CO2. After 8 days of culture the differentiated foci extract were measured by staining with 1% alcian blue. To assess the teratogenic effects of cyclosporine, it was placed in the culture well together with the cells. Results showed that the decrease in the expression of the extracellular matrix at dose of 0.01 molar of cyclosporine is due to limb bud cell toxicity rather than inhibition of cell differentiation