The value of LYM-1 cells for examining vacuole formation and loss of cell viability induced by culture supernates of Helicobacter pylori

Emblica officinalis extract induces autophagy and inhibits human ovarian cancer cell proliferation, angiogenesis, growth of mouse xenograft tumors

Patients with ovarian cancer (OC) may be treated with surgery, chemotherapy and/or radiation therapy, although none of these strategies are very effective. Several plant-based natural products/dietary supplements, including extracts from Emblicaofficinalis (Amla), have demonstrated potent anti-neoplastic properties. In this study we determined that Amla extract (AE) has anti-proliferative effects on OC cells under both in vitro and in vivo conditions. We also determined the anti-proliferative effects one of the components of AE, quercetin, on OC cells under in vitro conditions. AE did not induce apoptotic cell death, but did significantly increase the expression of the autophagic proteins beclin1 and LC3B-II under in vitro conditions. Quercetin also increased the expression of the autophagic proteins beclin1 and LC3B-II under in vitro conditions. AE also significantly reduced the expression of several angiogenic genes, including hypoxia-inducible factor 1α (HIF-1α) in OVCAR3 cells. AE acted synergistically with cisplatin to reduce cell proliferation and increase expression of the autophagic proteins beclin1 and LC3B-II under in vitro conditions. AE also had anti-proliferative effects and induced the expression of the autophagic proteins beclin1 and LC3B-II in mouse xenograft tumors. Additionally, AE reduced endothelial cell antigen – CD31 positive blood vessels and HIF-1α expression in mouse xenograft tumors. Together, these studies indicate that AE inhibits OC cell growth both in vitro and in vivo possibly via inhibition of angiogenesis and activation of autophagy in OC. Thus AE may prove useful as an alternative or adjunct therapeutic approach in helping to fight OC.

Serum-free culture of H pylori intensifies cytotoxicity

AIM: To perform a long culture passage of H pylori without serum, taking into account its cytotoxicity and the presence of the probable new cytotoxic factor.

METHODS: One sample of H pylori 60190 (ATCC 49503) was grown on Brain Heart Infusion (BHI) agar containing 0.5% 2,6-di-O-methyl-β-cyclodextrin without any serum, being passaged 70-100 times every 3-4 d for approximately 2 h, while another sample of H pylori contained 70 mL/L fetal calf serum without 2,6-di-O-methyl-β-cyclodextrin. Their supernatant and extract after 16 h in culture were evaluated for changes in cell morphology and for cell viability using HeLa cells. Furthermore, the characteristics of the probable cytotoxic factor in the extract were examined on partial purification studies and its cytotoxicity was evaluated in various human cells.

RESULTS: The supernatant and the extract of the bacterium grown on serum-free medium had strong cytotoxicity compared with those grown on serum-containing medium. They irreversibly damaged HeLa cells without vacuolation that was altogether different from that of the bacterium when grown with serum. Their cytotoxicity was easily measured by cell viability assay. The probable cytotoxic factor partially purified and detected by chromatography had characteristics difference from that of vacuolating toxin and a broad cytotoxicity toward various cell lines.

CONCLUSION: Serum-free long culture method of H pylori makes its supernatant and its extract cytotoxic enough to be easily measured by cell viability assay. The probable cytotoxic factor has a unique characteristic and might be a new cytotoxin.