METHOD: B. frutescens leaves extracts were prepared using Soxhlet apparatus with solvents of different polarity. The selective cytotoxicity of these extracts at various concentrations (20 to 160 μg/ml) were tested using cell viability assay after 24, 48 and 72 h of treatment. The IC50 value in human breast cancer (MCF-7 and MDA-MB-231) and mammary breast (MCF10A) cell lines were determined. Apoptotic study using AO/PI double staining was performed using fluorescent microscope. The glucose uptake was measured using 2-NBDG, a fluorescent glucose analogue. The phytochemical screening was performed for alkaloids, flavonoids, tannins, triterpenoids, and phenols.
RESULTS: B. frutescens leaves extracts showed IC50 value ranging from 10 -127μg/ml in MCF-7 cells after 72 h of treatment. Hexane extract had the lowest IC50 value (10μg/ml), indicating its potent selective cytotoxic activity. Morphology of MCF-7 cells after treatment with B. frutescens extracts exhibited evidence of apoptosis that included membrane blebbing and chromatin condensation. In the glucose uptake assay, B. frutescens extracts suppressed glucose uptake in cancer cells as early as 24 h upon treatment. The inhibition was significantly lower compared to the positive control WZB117 at their respective IC50 value after 72 h incubation. It was also shown that the glucose inhibition is selective towards cancer cells compared to normal cells. The phytochemical analysis of the extract using hexane as the solvent in particular gave similar quantities of tannin, triterpenoids, flavonoid and phenols. Presumably, these metabolites have a synergistic effect in the in vitro testing, producing the potent IC50 value and subsequently cell death.
CONCLUSION: This study reports the potent selective cytotoxic effect of B. frutescens leaves hexane extract against MCF-7 cancer cells. B. frutescens extracts selectively suppressed cancer cells glucose uptake and subsequently induced cancer cell death. These findings suggest a new role of B. frutescens in cancer cell metabolism.
MATERIALS AND METHODS: In this experimental study, female ICR mice (6-8 weeks old) were superovulated and cohabited with fertile males for 24 hours. Afterwards, their ovi- ducts were excised and embryos harvested. Embryos at the 2-cell stage were catego- rized as EC embryos, while zygotes with two pronuclei were categorized as LC embryos. Embryos were cultured in M16 medium supplemented with 3% bovine serum albumin (BSA) in a humidified 5% CO2atmosphere. Control embryos were cultured until the blastocyst stage without vitrification. Experimental embryos at the 2-cell stage were vitri- fied for one hour using 40% v/v ethylene glycol, 18% w/v Ficoll-70 and 0.5 M sucrose as the cryoprotectant. We recorded the numbers of surviving embryos from the control and experimental groups and their development until the blastocyst stage. Results were analyzed using the chi-square test.
RESULTS: A significantly higher proportion of EC embryos (96.7%) from the control group developed to the blastocyst stage compared with LC embryos (57.5%, P<0.0001). Similarly, in the experimental group, a significantly higher percentage of vitrified EC embryos (69.4%) reached the blastocyst stage compared to vitrified LC embryos (27.1%, P<0.0001).
CONCLUSION: Vitrified EC embryos are more vitrification tolerant than LC embryos. Prese- lection of EC embryos may be used as a tool for selection of embryos that exhibit higher developmental competence after vitrification.
MATERIAL/METHODS: Fifty female mice, aged 4-6 weeks, were used in this study. Animals were superovulated, cohabitated overnight, and sacrificed. Fallopian tubes were excised and flushed. Embryos at the 2-cell stage were collected and cultured to obtain 4- and 8-cell stages before being cryopreserved using vitrification and slow freezing. Fixed embryos were stained with fluorescence-labelled antibodies against actin and tubulin, as well as DAPI for staining the nucleus. Labelled embryos were scanned using CLSM and images were analyzed with Q-Win software V3.
RESULTS: The fluorescence intensity of both vitrified and slow-frozen embryos was significantly lower for tubulin, actin, and nucleus as compared to non-cryopreserved embryos (p<0.001). Intensities of tubulin, actin, and nucleus in each stage were also decreased in vitrified and slow-frozen groups as compared to non-cryopreserved embryos.
CONCLUSIONS: Cryopreservation of mouse embryos by slow freezing had a more detrimental effect on the actin, tubulin, and nucleus structure of the embryos compared to vitrification. Vitrification is therefore superior to slow freezing in terms of embryonic cryotolerance.