METHODS: To evaluate the in vitro cytotoxicity of flower of Allium atroviolaceum, methanol extract at a dose range from 100 to 3.12 μg/ml was assessed against the HepG2 hepatocarcinoma cell line, and also on normal 3T3 cells, by monitoring proliferation using the MTT assay method. A microscopy study was undertaken to observe morphological changes of HepG2 cells after treatment and cell cycle arrest and apoptosis were studied using flow cytometry. The apoptosis mechanism of action was assessed by the level of caspase-3 activity and expression of apoptosis related genes, Bcl-2, Cdk1 and p53. The combination effect of the methanolic extract with doxorubicin was also investigated by determination of a combination index.
RESULTS: The results demonstrated growth inhibition of cells in both dose- and time-dependent manners, while no cytotoxic effect on normal cell 3T3 was found. The results revealed the occurrence of apoptosis, illustrated by sub-G0 cell cycle arrest, the change in morphological feature and annexin-V and propidium iodide staining, which is correlated with Bcl-2 downregulation and caspase-3 activity, but p53-independent. In addition, a combination of Allium atroviolaceum and doxorubicin led to a significant synergistic effect.
CONCLUSION: These findings suggest that Allium atroviolaceum flower extract has potential as a potent cytotoxic agent against HepG2 cell lines, as it has commendable anti-proliferative activities against human hepatocarcinoma and it can be considered as an effective adjuvant therapeutic agent after the clinical trials.
METHODS AND RESULTS: Effects of GBR, brown rice, and white rice (WR) on fasting plasma glucose and selected genes were studied in type 2 diabetic rats. GBR reduced plasma glucose and weight more than metformin, while WR worsened glycemia over 4 weeks of intervention. Through nutrigenomic suppression, GBR downregulated gluconeogenic genes (Fbp1 and Pck1) in a manner similar to, but more potently than, metformin, while WR upregulated the same genes. Bioactives (gamma-amino butyric acid, acylated steryl glycoside, oryzanol, and phenolics) were involved in GBR's downregulation of both genes. Plasma glucose, Fbp1 and Pck1 changes significantly affected the weight of rats (p = 0.0001).
CONCLUSION: The fact that GBR downregulates gluconeogenic genes similar to metformin, but produces better glycemic control in type 2 diabetic rats, suggests other mechanisms are involved in GBR's antihyperglycemic properties. GBR as a staple could potentially provide enhanced glycemic control in type 2 diabetes mellitus better than metformin.
AIM OF THE STUDY: To determine the mechanism of action of pure clausenidin crystals in the induction of hepatocellular carcinoma (hepG2) cells apoptosis.
MATERIALS AND METHODS: Pure clausenidin was isolated from Clausena excavata Burm.f. and characterized using (1)H and (13)C NMR spectra. Clausenidin-induced cytotoxicity was determined by MTT assay. The morphology of hepG2 after treatment with clausenidin was determined by fluorescence and Scanning Electron Microscopy. The effect of clausenidin on the apoptotic genes and proteins were determined by real-time qPCR and protein array profiling, respectively. The involvement of the mitochondria in clausenidin-induced apoptosis was investigated using MMP, caspase 3 and 9 assays.
RESULTS: Clausenidin induced significant (p<0.05) and dose-dependent apoptosis of hepG2 cells. Cell cycle assay showed that clausenidin induced a G2/M phase arrest, caused mitochondrial membrane depolarization and significantly (p<0.05) increased expression of caspases 3 and 9, which suggest the involvement of the mitochondria in the apoptotic signals. In addition, clausenidin caused decreased expression of the anti-apoptotic protein, Bcl 2 and increased expression of the pro-apoptotic protein, Bax. This finding was confirmed by the downregulation of Bcl-2 gene and upregulation of the Bax gene in the treated hepG2 cells.
CONCLUSION: Clausenidin extracted from Clausena excavata Burm.f. is an anti-hepG2 cell compound as shown by its ability to induce apoptosis through the mitochondrial pathway of apoptosis. Clausenidin can potentially be developed into an anticancer compound.