RESUMO
Salvianolic acid B (Sal B) has strong antioxidant and anti-fibrosis effects, which are related to the transforming growth factor ß/Smad signaling pathway. However, how Sal B affects this antioxidant pathway and the phosphorylation (p-) of Smad2 at both the COOH-terminal (pSmad2C) and linker region (pSmad2L) are unknown. The aims of the present study were to investigate the underlying mechanisms of Sal B on acute and chronic liver injury induced by CCl4 and H2O2, and its effects on p-Smad2C/L. In in vivo experiments, acute and chronic liver injury models were induced by CCl4, and the oxidative damage cell model was established in vitro with H2O2. Liver histopathology was assessed using hematoxylin and eosin and Van Gieson's staining. Moreover, serum biochemical indicators were analyzed using specific assay kits. Furthermore, the present study evaluated the oxidant/antioxidant status in acute and chronic liver injury models by oxidative stress parameters such as malondialdehyde, glutathione and superoxide dismutase. In addition, western blot analysis was performed to analyze the protein expression levels of pSmad2C, pSmad2L, nuclear factor erythroid-2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). It was found that Sal B improved liver histology, decreased the levels of aminotransferase and attenuated oxidative stress in acute and chronic liver injury models. Additionally, the protein expression levels of pSmad2C and pSmad2L were decreased, but Nrf2 and HO-1 expression levels were increased both in vivo and in vitro. Collectively, the present results suggested that Sal B may protect against acute and chronic liver injury via inhibition of Smad2C/L phosphorylation, and the Nrf2/HO-1 signaling pathway may play an important role in this process.
RESUMO
Orius strigicollis (Poppius) is an anthocorid bug with high foraging ability on thrips as well as on mites, and the bug has been considered as a potential biological control agent in Taiwan. Life table and predation studies of O. strigicollis fed on Cadra cautella (Walker) and Tetranychus urticae (Koch) eggs were conducted at 25 ± 1°C. Data were analyzed and compared using TWOSEX-MSChart and CONSUME-MSChart software. O. strigicollis fed on eggs of C. cautella, a substitute prey, showed significantly higher survival rate and developmental rate than individuals fed on their natural prey, T. urticae eggs. The fecundity of O. strigicollis fed on C. cautella eggs was, on average, 13.2 times higher than that of those fed on T. urticae eggs, despite of the fact that during the entire nymphal stage, the consumption rate of O. strigicollis on T. urticae eggs was ca. 9 times higher than on almond moth eggs The conversion rate (i.e., number of prey eggs needed to produce one predator egg) for this predatory bug reared on T. urticae eggs and almond moth eggs were 604.6 and 6.0, respectively, indicating that almond moth eggs served as an effective alternative prey for ensuring the predator's reproduction. This is the first study pertaining to the population parameters and predation rates of O. strigicollis using the age-stage two-sex approach to describe differences between O. strigicollis populations reared on natural and alternative preys. This information may be useful in mass rearing programs and field application involving this biological control agent.
