RESUMO
A human hepatoma cell line, Hep G2 cells, is a reliable system for the study of alcohol-induced hepatotoxicity. In this study, we investigated the effect of an aqueous extract of Asparagus cochinchinensis(MERRIL) (Liliaceae) roots (ACAE) on ethanol (EtOH)-induced cytotoxicity in Hep G2 cells. ACAE (1-100 microg/ml) dose-dependently inhibited the EtOH-induced tumor necrosis factor-alpha (TNF-alpha) secretion. ACAE (1-100 microg/ml) also inhibited the EtOH and TNF-alpha-induced cytotoxicity. Furthermore, we found that ACAE inhibited the TNF-alpha-induced apoptosis of Hep G2 cells. These results suggest that ACAE may prevent the EtOH-induced cytotoxicity through inhibition of the apoptosis of Hep G2 cells.
Assuntos
Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/metabolismo , Etanol/toxicidade , Liliaceae , Neoplasias Hepáticas/metabolismo , Extratos Vegetais/uso terapêutico , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Carcinoma Hepatocelular/tratamento farmacológico , Sobrevivência Celular/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Etanol/antagonistas & inibidores , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Raízes de Plantas , Células Tumorais Cultivadas/efeitos dos fármacos , Fator de Necrose Tumoral alfa/metabolismoRESUMO
An RNA-dependent RNA polymerase activity was found associated with virions of tomato spotted wilt virus (TSWV), a plant- and insect-infecting member of the family Bunyaviridae. Radiolabeled nucleoside triphosphates were incorporated into trichloroacetic acid-precipitable products by detergent-disrupted, purified TSWV virions. Incorporation was reduced to near-background levels when RNase was present in the reaction mixture. The predominantly double-stranded RNA products were RNase-resistant at high but not low salt concentrations. The activity required manganese and was independent of a DNA template. Discrete products of approximately 3.0 kb and heterogeneous smaller products were synthesized that hybridized to purified TSWV RNA and transcripts of cDNA clones encompassing parts of each of the three genomic RNAs. The predominant products were viral sense although significant amounts of viral complementary sense S RNA products were also synthesized.