Jianqing Yu

Anticancer, antioxidant and antimicrobial activities of the essential oil of Lycopus lucidus Turcz. var. hirtus Regel.

This study was designed to examine the anticancer, antioxidant and antimicrobial activities of the essential oil from Lycopus lucidus Turcz. var. hirtus Regel. The essential oil treatment to six human cancer cell lines resulted in a dose-dependent inhibition of cell growth. The cytotoxicity of the essential oil on liver carcinoma and breast cancer cell lines was significantly stronger than on other cell lines. The essential oil can induce apoptosis of the liver carcinoma cell line Bel-7402 and decrease the intracellular GSH level. The antioxidant effect of the essential oil was evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical (OH) scavenging assays. The essential oil exhibited moderate antioxidant activity. The antimicrobial activity of the essential oil was evaluated against eight microorganisms using the disc diffusion and broth microdilution methods. The essential oil also showed moderate antimicrobial activity. These suggest that the essential oil could hold a good potential for use in the pharmaceutical industry.

Alantolactone induces activation of apoptosis in human hepatoma cells

Alantolactone, a sesquiterpene lactone, possesses anti-inflammatory property. In this study, we provide evidence that it could be developed as a novel agent against human liver cancer. We observed that alantolactone treatment to HepG2, Bel-7402 and SMMC-7721 cells, human liver cancer cell lines resulted in a dose-dependent inhibition of cell growth. We selected HepG2 cell line as a test model system. Alantolactone treatment of HepG2 cells resulted in a dose-dependent induction of apoptosis and arrest of cells in G2-M phase. This induction of apoptosis seems to be mediated via modulating the protein levels of Bcl-2 family and activation of caspases. Moreover, caspase-8 and Bid activation, loss of mitochondrial transmembrane potential and cytochrome c release suggest the existence of a cross-talk between the death receptor and the mitochondrial pathways. We also observed that alantolactone treatment of cells resulted in a dose-dependent decrease in NF- κB/p65. In addition, a significant and progressive increase in the level of p53 protein in alantolactone-treated cells was observed. Taken together, our data suggest that alantolactone could be developed as an agent against human liver cancer.

Emodin Regulates Apoptotic Pathway in Human Liver Cancer Cells

Emodin, a natural anthraquinone, has been reported to possess antiproliferative effects in many cancer cell lines. However, anticancer mechanism against human liver cancer remains unclear. In this study, we observed that emodin induced apoptosis in HepG2 cells and caused a significant accumulation of cells in the G1 phase. Western blot data showed that emodin treatment caused the increasing of release of cytochrome c into cytosol from mitochondria and the activation of caspase‐8 and caspase‐9, which suggest that the intrinsic and extrinsic pathways could be involved. Emodin treatment also resulted in a dose‐dependent accumulation of intracellular reactive oxygen species. Furthermore, emodin increased the protein level of p53 and decreased the protein level of NF‐κB/p65 in HepG2 cells, which indicated these two regulators might play a role in emodin‐induced apoptosis. Computational modeling showed that emodin could directly bind to the BH3 domain of Bcl‐2 through forming one hydrogen bond with Ala146 residue in Bcl‐2. From these examinations, emodin not only significantly downregulated expression of Bcl‐2 but also inhibited the heterodimerization of Bcl‐2 with Bax because of strong interaction between emodin and Bcl‐2. These suggest that emodin induces apoptosis in liver cancer cell line through a multifaceted complex cascade of events. Copyright

Activation of apoptosis by ethyl acetate fraction of ethanol extract of Dianthus superbus in HepG2 cell line

Dianthus superbus L. is commonly used as a traditional Chinese medicine. We recently showed that ethyl acetate fraction (EE-DS) from ethanol extract of D. superbus exhibited the strongest antioxidant and cytotoxic activities. In this study, we examined apoptosis of HepG2 cells induced by EE-DS, and the mechanism underlying apoptosis was also investigated. Treatment of HepG2 cells with EE-DS (20-80 μg/ml) for 48 h led to a significant dose-dependent increase in the percentage of cells in sub-G1 phase by analysis of the content of DNA in cells, and a large number of apoptotic bodies containing nuclear fragments were observed in cells treated with 80 μg/ml of EE-DS for 24 h by using Hoechst 33258 staining. These data show that EE-DS can induce apoptosis of HepG2 cells. Immunoblot analysis showed that EE-DS significantly suppressed the expressions of Bcl-2 and NF-κB. Treatment of cells with EE-DS (80 μg/ml) for 48 h resulted in significant increase of cytochrome c in the cytosol, which indicated cytochrome c release from mitochondria. Activation of caspase-9 and -3 were also determined when the cells treated with EE-DS. The results suggest that apoptosis of HepG2 cells induced by EE-DS could be through the mitochondrial intrinsic pathway. High performance liquid chromatography (HPLC) data showed that the composition of EE-DS is complicated. Further studies are needed to find the effective constituents of EE-DS.

Sensitisation of ovarian cancer cells to cisplatin by flavonoids from Scutellaria barbata

Combination of natural components with anticancer drugs is a new strategy for cancer chemotherapy to increase antitumour responses. In this study, we investigated the sensitisation effects of nine flavonoids from Scutellaria barbata to cisplatin (CDDP) on human ovarian cancer cells. The combinations of three flavonoids with CDDP showed the synergistic effects. The intracellular reactive oxygen species and the antioxidant activity were measured. The data suggest that the synergistic effects of flavonoids with CDDP on ovarian cancer cells did not directly correlate with their redox properties, but could be associated with the positions of hydroxyl group and methoxy group of flavonoids.

Cytotoxic constituents of ethyl acetate fraction from Dianthus superbus

The ethyl acetate fraction (EE-DS) from Dianthus superbus was found to possess the cytotoxic activity against cancer cells in previous study. To investigate cytotoxic constituents, the bioassay-guided isolation of compounds from EE-DS was performed. Two dianthramides (1 and 2), three flavonoids (3–5), two coumarins (6 and 7) and three other compounds (8–10) were obtained. Structures of isolated compounds were identified by spectroscopic analysis. Cytotoxicity of the compounds against HepG2 cells was evaluated. Compound 1 showed the strongest cytotoxicity, compounds 10, 4, 3 and 5 had moderate cytotoxicity.

Protocatechuic acid inhibits the growth of ovarian cancer cells by inducing apoptosis and autophagy: Protocatechuic acid inhibits growth of ovarian cancer cells

Protocatechuic acid (PCA), present in many fruits and vegetables, exhibited various biological activities. Here, we provided evidence that it could be developed as a potential chemotherapeutic agent against human ovarian cancer. We found that PCA treatment significantly reduced the cell viability and colony formation of OVCAR‐3, SKOV‐3, and A2780 cells. OVCAR‐3 cells were selected as a test model system for investigating molecular mechanism. PCA treatment induced cell cycle arrest in G2/M phase, the activation of poly (ADP‐ribose) polymerase (PARP) and caspase‐3, the upregulation of Bax and downregulation of Bcl‐2 in OVCAR‐3 cells. We also observed that PCA treatment significantly caused upregulation of autophagy‐related protein LC3‐II and induced GFP‐LC3 puncta formation. Furthermore, cotreatment with PCA and autophagy inhibitor attenuated the cytotoxicity induced by PCA in OVCAR‐3 cells. Moreover, our results showed that PCA increased the intracellular levels of glutathione and decreased intracellular reactive oxygen species that might be related to the inhibition effect of PCA on OVCAR‐3 cells. Our data revealed that PCA could modulate apoptosis and autophagy, suggesting the potential of PCA for chemoprevention and chemotherapy of ovarian cancer.