Asian Pacific Journal of Tropical Biomedicine

519-526

Authors: Teeranai Ittiudomrak, Songchan Puthong, Tanapat Palaga, Sittiruk Roytrakul, Chanpen Chanchao

Objective: To find new compounds in order to overcome the mainstay of metastatic breast cancer due to the adverse side effects from, and increasing resistance to, current chemotherapeutic agents. Methods: α-Mangostin and apigenin were reported in comparison to doxorubicin, a chemotherapeutic drug. Ductal carcinoma (BT474) cell line and non-tumorigenic epithelial tissue from mammary gland (MCF-10A) were used. Cell viability assessment was calculated by the standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method. Cell morphology was investigated by light microscopy. By flow cytometry analysis, programmed cell death was observed using annexin V and propidium iodide staining while cell-cycle arrest was observed using propidium iodide staining. Change in transcriptional expression was evaluated by real-time quantitative reverse transcription PCR. Results: In 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, the result revealed α-mangostin and apigenin were more cytotoxic to BT474 cells. Longer exposure times to α-mangostin and apigenin caused more floating cells and a lower density of adhered cells with more vacuoles present in the colonies in BT474 only. α-Mangostin and apigenin caused necrosis in BT474 cells in a 24 h exposure, but a small amount of early apoptotic cells could also be detected at 24, 48 and 72 h exposure, whereas doxorubicin caused early apoptosis to BT474 cells at 24 h. Transcript expression and activity analysis supported caspase-3 was involved in the death of BT474 cells treated by all compounds. Moreover, α-mangostin and apigenin arrested the cell-cycle at the G1-phase, but at the G2/M-phase by doxorubicin. All three compounds induced a change in transcript expression levels of inflammation-associated, proto-oncogene, autophagy-associated and apoptosis-associated genes. Conclusions: α-Mangostin and apigenin are worth investigating as potential new sources of chemotherapeutic agents for breast cancer treatment.

533-539

Authors: Muhammad Eka Prastya, Rika I Astuti, Irmanida Batubara, Aris T Wahyudi

Objective: To analyze potential activation of oxidative stress tolerance systems by SAB E-41 bacterial extract in promoting the life span of yeast Schizosaccharomyces pombe. Methods: In vitro analysis was done to assess antioxidant activity of SAB E-41 bacterial extract. Antiaging property of the particular extract was then assayed through spot test and chronological life span assays. Furthermore, sty1 mitogen-activated protein kinase, pap1 transcriptional factor of oxidative stress response and its downstream genes, ctt1 were evaluated via real time PCR. The protein level of ctt1 was then observed via Western Blot analysis. In addition, accumulation of reactive oxygen species and mitochondrial activity were conducted to understand the effect of SAB E-41 upon oxidative stress response systems in vivo. Results: The IC50 values of corresponding extract for antioxidant (DPPH; ABTS) and antiglycation were 402.40, 358.13 and 683.55 μg/mL, respectively. In addition, SAB E-41 extract (750 μg/mL) exhibited antiaging properties, which could be attributed to significant up-regulation of oxidative stress response genes, sty1, pap1 and ctt1. Interestingly, SAB E-41 extract could enhance stress tolerance phenotype of Schizosaccharomyces pombe against H2O2-induced oxidative stress. These results were supported by increasing mitochondrial activity and reactive oxygen species intracellular levels. Conclusions: SAB E-41 extract could promote yeast life span likely via up-regulation of oxidative stress responses in yeast. Our results suggest that adaptive response via up-regulation of oxidative stress transcriptional factors, and its downstream gene, ctt1, as well as mitochondrial activity contributes in combating oxidative stress thus promoting yeast life span.

548-553

Authors: Hilal Irmak Sapmaz, Azibe Yıldız, Alaadin Polat, Nigar Vardı, Evren Köse, Kevser Tanbek, Songül Çuğlan

Objective: To explore the effects of Nigella sativa oil (NSO) on the histopathological and biochemical changes that inhaled formaldehyde (FA) induces on the testicular tissue of rats. Methods: Thirty three adult male rats were separated into five groups as follows: C, the control group; 4FA group which received FA for 4 weeks; 13FA group which was given FA for 13 weeks; 4FA+NSO group which was administered FA plus NSO for 4 weeks; 13FA+NSO group which was treated with FA plus NSO for 13 weeks. FA was administered through inhalation for 8 h 5 days a week at a dose of 5 ppm in a special glass cage, and NSO was administered orally 1 mL/kg once daily. Rats were decapitated at the end of the experiment and testicular tissue specimens were harvested for histopathologic and biochemical assessment. Results: Compared to the C group, reduction was observed in the number of intact tubules and in the mean germinative epithelium thickness of the FA groups. Significant increase was observed in the number of intact tubules with the long-term (13 weeks) administration of NSO together with FA. Reduced glutathione peroxidase activity was found and oxidative stress index values were measured higher in the 4FA and 13FA groups versus the C group (P<0.05). Moreover, total antioxidant status levels decreased only in the 4FA group (P<0.05) while only the 13FA group significantly increased malondialdehyde levels and reduced catalase activities in comparison with the C group. In the 13FA+NSO group, malondialdehyde levels decreased however glutathione peroxidase and catalase activities increased compared to the 13FA group. Differences measured in total antioxidant status levels were found to be statistically significant only between the 4FA and the 4FA+NSO groups. Conclusions: NSO as an antioxidant should be used for a longer term to achieve protective efficacy both histopathologically and biochemically in the testicular tissue.