The effect of infusion time on Echium amoenum extract -induced hepatotoxicity in vitro.

Echium amoenum is an annual herb native to the northern mountains of Iran which has medicinal application. Petals of Echium amoenum (Gole-Gavzaban) is one of the most valuable medicinal plants in Iranian folk medicine. The dry petals of E. amoenum have long been used as a sedative, tonic, anxiolytic and as a treatment for sore throat, cough and inflammation. Previous studies have shown that petals of E. amoenum contain four toxic pyrrolizidine alkaloids but conflicting results have been acquired in experimental studies investigating the hepatotoxicy of E. amoenum. However, the direct effect of E. amoenum on liver cells and the complete mechanisms of its possible cytotoxic effects toward these cells remain to be defined. The main aim of this study was to assay the mechanisms underlying the toxic effects of E. amoenum toward hepG2 cells. E. amoenum extract was obtained by infusion of dried petals in hot water (90 centigrade) for 15 or 30 min. Cell viability and mechanistic parameters were determined following 12 h incubation of hepG2 with E. amoenum extract that was obtained after 15 or 30 min infusion. The results indicated that E. amoenum extract exerts cytotoxic effects on hepG2 cells, probably through mitochondrial and lysosomal damage induced by glutathione depletion and oxidative stress.

Evaluating cellular uptake of gold nanoparticles in HL-7702 and HepG2 cells for plasmonic photothermal therapy.

AIM: A novel methodology is provided to quantitatively measure the gold (Au) mass internalized in a cell for effective implementation of plasmonic photothermal therapy (PPTT). MATERIALS & METHODS: The cellular uptake of 4-mercaptobenzoic acid-labeled Au nanoparticles (NPs) is investigated via Raman mapping and inductively coupled plasma-mass spectrometry and the efficiency of in vitro PPTT is evaluated. RESULTS & CONCLUSION: The cellular uptake is strongly affected by the size of the Au NPs, concentration of the Au NPs, incubation time and cell type. By optimizing the experimental parameters, the results show that a significant damage is caused to the HepG2 cells and slight harm is caused to the HL-7702 cells during PPTT. This demonstrates a high potential for developing effective photothermal therapy for tumor tissues.

Polyphyllin I induced-apoptosis is enhanced by inhibition of autophagy in human hepatocellular carcinoma cells.

BACKGROUND: Polyphyllin I (PPI), a bioactive phytochemical isolated from the rhizoma of Paris polyphyllin, exerts preclinical anticancer efficacy in various cancer models. However, the effects of PPI on regulatory human hepatocellular carcinoma (HCC) cell proliferation and its underlying mechanisms remain unknown. PURPOSE: This study investigated the antiproliferation effect of PPI on HCC cells and its underlying mechanisms. METHODS: Cell viability was measured by MTT assay. Cell death, apoptosis and acidic vesicular organelles (AVOs) formation were determined by flow cytometry. Protein levels were analyzed by Western blot analysis. RESULTS: PPI induced apoptosis through the caspase-dependent pathway and activated autophagy through the PI3K/AKT/mTOR pathway. Blockade of autophagy by pharmacological inhibitors or RNA interference enhanced the cytotoxicity and antiproliferation effects of PPI. Moreover, chloroquine (CQ) enhanced the antiproliferation effect of PPI on HCC cells via the caspase-dependent apoptosis pathway by inhibiting protective autophagy. Therefore, the combination therapy of CQ and PPI exhibited synergistic effects on HCC cells compared with CQ or PPI alone. CONCLUSION: The current findings strongly indicate that PPI can induce protective autophagy in HCC cells, thereby providing a novel target in potentiating the anticancer effects of PPI and other chemotherapeutic drugs in liver cancer treatment. Moreover, the combination therapy of CQ and PPI is an effective and promising candidate to be further developed as therapeutic agents in the treatment of liver cancer.