Apoptotic properties of Citrus sudachi Hort, ex Shirai (Rutaceae) extract on humanA549 and HepG2 cancer cells

Purpose: To investigate whether Citrus sudachi harvested at two stages of maturity can induce toxicity in a cell-specific manner and to determine the possible mechanisms of Citrus sudachi-induced cytotoxic responses in two types of cancer cells (human lung adenocarcinoma A549 and hepatocellular carcinoma HepG2 cells) and two normal cell lines (lung 16HBE140- and liver CHANG cells). Methods: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and annexin V/propidium iodidle assay were used to test the antiproliferative activity and apoptosis of methanol extract of Citrus sudachi, respectively. Griess reaction and reverse transcriptase-polymerase chain reaction (RT-PCR) were carried out to evaluate nitric oxide (NO•) production and the mRNA levels of inhibitors of apoptosis (IAP). Results: Citrus sudachi exerted cytotoxicity in a time-dependent manner in cancer cells which increased with increase in maturity but did not affect normal cells. Citrus sudachi was found to induce accumulation of cells in the sub-G1 cell cycle phase, fragmentation of DNA and cell death with characteristics of apoptosis, in both types of cancer cells. Moreover, Citrus sudachi upregulated cellular NO• produced by activation of nitric oxide synthase (NOS), while it suppressed the levels of IAP mRNA in both types of cancer cells. Conclusion: The results obtained suggest that Citrus sudachi induces apoptosis in A549 and HepG2 cells, which may be mediated by NO•. There is need for further studies on the role of Citrus sudachi in cancer treatment.

Characterization of volatile compounds of Albertisia papuana Becc root extracts and cytotoxic activity in breast cancer cell line T47D

Purpose: To evaluate the cytotoxic activity of chloroform and water root extracts of Albertisia papuana Becc. on T47D cell line and identify the volatile compounds of the extracts. Methods: The plant roots were extracted with chloroform and water using maceration and boiling methods, respectively. The cytotoxicity of the extracts on T47D were determined using 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Doxorubicin was used as reference drug in the cytotoxicity test while Probit analysis was used to calculate the Median Growth Inhibitory Concentration IC50 of the extracts. The volatile compounds in the chloroform and water root extracts were analyzed using Gas Chromatography-Mass Spectrophotometry GC-MS. Results: The IC50 of the chloroform and water extracts were 28.0 ± 6.0 and 88.0 ± 5.5 μg/mL, respectively whereas that of doxorubicin was 8.5 ± 0.1 μg/mL. GC-MS results showed that there were 46 compounds in the chloroform extract, out of which the five major components are ethyl linoleate (49.68 %), bicyclo (3.3.1) non-2-ene (29.29 %), ethyl palmitate (5.06 %), palmitic acid (3.67 %) and ethyl heptadecanoate (1.57 %).The water extract consisted of three compounds, butanoic acid (15.58 %); methyl cycloheptane (3.45 %), and methyl 2-O-methylpentofuranoside (80.96 %). Conclusion: The chloroform root extract of A. papuana Becc. had a fairly potent anticancer activity against breast cancer cells and may be further developed as an anticancer agent. Its major components were fatty acids and fatty acid esters.

Triptolide induces cell apoptosis in human stomach cancer cell via caspase 3-dependent cascade pathway

Purpose: To evaluate the effect of triptolide on the induction of cell apoptosis in human gastric cancer BGC-823 cells. Methods: The cytotoxicity of triptolide was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5- diphenyltetrazolium bromide (MTT) assay. The effect of triptolide on cell proliferation was measured using lactate dehydrogenase (LDH) assay. Cell apoptosis was determined by Annexin V/propidium iodide (PI) double-staining assay. Results: MTT results indicate that triptolide significantly decreased cancer cell numbers in dose- and time-dependent manners in MTT assay. Data from LDH assay showed that triptolide markedly induced cytotoxicity in gastric cancer cells. Triptolide also remarkably induced both early and late apoptotic process in BGC-823 cells. In addition, the compound down-regulated the expression of anti-apoptotic Bcell lymphoma-2 (bcl-2) and up-regulated the expression of pro-apoptotic BCL-2-associated X (bax) in a dose-dependent manner. Furthermore, the pro-apoptotic activity of triptolide was involved in the activation of caspase-3 pathway in BGC-823 cells. Conclusion: Taken together, the findings strongly indicates that the pro-apoptotic activity of triptolide is regulated by caspase 3-dependent cascade pathway, and thus needs to be further developed for cancer therapy.