Cytotoxic screening and antibacterial activity of Withaferin A.

Cancer and bacterial infections are among the leading causes of death worldwide. Plant-derived bioactive compounds constitute promising alternatives for development of new therapeutics. This study aimed at evaluating the biological activity of Withaferin A using 6 tumor cell lines: A549 (lung cancer), U87MG (glioblastoma), SH-SY5Y (neuroblastoma), B16-F10 (mouse melanoma), HeLa (uterine colon cancer) and K562 (chronic myeloid leukemia). In addition, 17 other standard bacterial strains and several multidrug resistant bacteria (MDR) clinical isolates were examined. Cell viability was assessed using the following assays: MTT, neutral red, and dsDNA PicoGreen®. Further, oxidative stress was measured by quantification of reactive oxygen species (ROS) production. The activity against bacteria was determined by the minimum inhibitory concentration (MIC), minimum bacterial concentration (CBM) and antibiofilm activity in the production of strains. Withaferin A was effective, as evidenced by its cytotoxic activity in tumor cell lines, enhanced ROS production in tumor cells and bactericidal and antibiofilm activity. Data demonstrated that Withaferin A may be therapeutically considered as an antitumor and antibacterial agent.

Human pegivirus-1 (HPgV-1) RNA prevalence and genotypes in volunteer blood donors from the Brazilian Amazon.

OBJECTIVES: The objectives of this study were to evaluate the prevalence of Human Pegivirus-1 (HPgV-1) viremia and genotype diversity among healthy blood donors from the Eastern Brazilian Amazon (city of Macapá, State of Amapá). There is little information for prevalence and circulation of HPgV-1 in this remote Brazilian region. MATERIALS AND METHODS: We conducted a study evaluating the HPgV-1 RNA prevalence and circulating genotypes in 431 volunteer blood donors originating from the Eastern Brazilian Amazon. The obtained HPgV-1 positive samples were submitted to sequencing and genotyping analysis in order to examine the genotype diversity of this virus in the Brazilian Amazon. RESULTS: Our results demonstrated a prevalence of HPgV-1 RNA in 9.5% of the tested blood donors. The phylogenetic analyses of the detected positive samples showed the presence of HPgV-1 genotypes 1, 2 and 3. The most frequently detected genotype was 2 (78.0% of the cases) represented by sub-genotypes 2A (39.0%) and 2B (39.0%). At lower rates, genotypes 1 (14.6%) and 3 (7.4%) were also detected. CONCLUSION: Our results revealed the presence of genotypes with European, Asiatic and African endemicity in Amazonian blood donors, probably due to the complex miscegenation processes that took place in this Brazilian region. More investigations, including information for the prevalence of HPgV-1 RNA in blood donors from other Latin American countries are needed to estimate the viremic rates and genotype distribution of this virus in a highly diverse continent like South America.