cytochrome-c-t and brusatol

It has been reported that brusatol (BRU) reduces cellular reactive oxygen species (ROS) level under hypoxia; here the protective effect of BRU against oxygen-glucose deprivation/reoxygenation (OGD-R)-induced injury in HepG2 cells and against anoxia/reoxygenation (A/R)-induced injury in rat liver mitochondria was investigated.. OGD-R-induced HepG2 cell viability loss was detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide and trypan blue staining. Mitochondrial ROS level in HepG2 cells was measured by MitoSOX staining. The cellular malondialdehyde and adenosine triphosphate level was measured by commercial kits. The mitochondrial membrane potential in HepG2 cells was measured by JC-1 staining. The protein level was detected by Western blotting. Rat liver mitochondria were separated by differential centrifugation. A/R-induced injury in isolated rat liver mitochondria was established by using a Clark oxygen electrode. The ROS generation in isolated mitochondria was evaluated using Amplex red/horseradish peroxidase.. BRU reduced mitochondrial ROS level and alleviated oxidative injury in HepG2 cells, thereby significantly inhibited OGD-R-induced cell death. During OGD-R, BRU improved mitochondrial function and inhibited the release of cytochrome c. Furthermore, BRU showed a clear protective effect against A/R-induced injury in isolated rat liver mitochondria. When isolated rat liver mitochondria were pretreated with BRU, A/R-induced ROS generation was significantly decreased, and mitochondrial respiratory dysfunction was ameliorated.. BRU pretreatment attenuated OGD-R-induced injury in HepG2 cells and A/R-induced injury in isolated rat liver mitochondria by inhibiting mitochondrial ROS-induced oxidative stress.

Topics: Adenosine Triphosphate; Animals; Cytochromes c; Glucose; Hep G2 Cells; Humans; Male; Malondialdehyde; Membrane Potential, Mitochondrial; Mitochondria; Oxidative Stress; Oxygen; Protective Agents; Quassins; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Reperfusion Injury

Colorectal cancer (CRC) is a common and life‑threatening type of malignant cancer, which is associated with a high mortality rate. Cisplatin (CDDP) is a commonly used chemotherapy drug with significant side effects. Brusatol (BR) is one of the principal chemical compounds isolated from the Chinese herb Bruceae Fructus, which has been reported to markedly inhibit the proliferation of numerous cancer cell lines. The present study aimed to investigate the possible synergistic anticancer effects of CDDP combined with BR on CT‑26 cells, and to evaluate the underlying mechanisms of action. The growth inhibitory effects of BR, CDDP, and BR and CDDP cotreatment on CT‑26 cells were assessed by MTT assay. Cell apoptosis were determined by flow cytometry and western blot analysis. The results indicated that compared with single‑agent treatment, cotreatment of CT‑26 cells with CDDP and BR synergistically inhibited cell proliferation and increased cellular apoptosis. Furthermore, treatment of CT‑26 cells with CDDP and BR resulted in a marked increase in the release of cytosolic cytochrome c, decreased expression of procaspase‑3 and procaspase‑9, and upregulation of the B‑cell lymphoma 2 (Bcl‑2)‑associated X protein/Bcl‑2 ratio compared with treatment with BR or CDDP alone. These results strongly suggested that the combination of CDDP and BR was able to produce a synergistic antitumor effect in CRC cells, thus providing a solid foundation for further development of this combination regimen into an effective therapeutic method for CRC.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; bcl-2-Associated X Protein; Caspases; Cell Line, Tumor; Cell Shape; Cisplatin; Colorectal Neoplasms; Cytochromes c; Drug Synergism; Gene Expression Regulation, Neoplastic; Inhibitory Concentration 50; Mice; Quassins

Brucea javanica (L.) Merr. is a medicine plant distributed widely throughout Asia where its bitter fruits have been used traditionally in medicine for treating various ailments and controlling some pests. In recent years, concerns over the potential impact of synthetic pesticides on human health and environment have now become more pressing to develop environmentally friendly pesticides. In this paper, brusatol, a quassinoid, was isolated from the fruit of B. javanica, and identified using X-ray crystallographic analysis. Results showed that brusatol has potent contact toxicity (LD50, 2.91 μg/larva, 72 h) and anfieedant activity (AFC50, 17.4 mg/L, 48 h) against the third-instar larvae of Spodoptera exigua. Brusatol demonstrated cytotoxic effects to the tested insect cell lines, IOZCAS-Spex-II and Sf21, in a time- and dose-dependent manner. After brusatol treatment, apoptotic cell death with the DNA fragmentation, activation of caspase-3 and release of cytochrome c was preliminarily observed in both IOZCAS-Spex-II and Sf21. These results indicated the existence of apoptotic death with the mitochondrial-dependent pathway induced by brusatol in Sf21 and IOZCAS-Spex-II cell lines. Our studies will provide important knowledge to understand mechanisms of action of brusatol and to develop brusatol and its derivatives as insecticides.

Topics: Animals; Apoptosis; Brucea; Caspase 3; Cell Line; Cell Proliferation; Cell Survival; Cytochromes c; DNA Fragmentation; Feeding Behavior; Fruit; Insecta; Insecticides; Larva; Molecular Structure; Quassins; Seeds