Astilbin protects from sepsis-induced cardiac injury through the NRF2/HO-1 and TLR4/NF-κB pathway

Cardiac dysfunction and arrhythmia are severe complications of sepsis-induced cardiomyopathy and are associated with an increased risk of morbidity and mortality. Currently, the precise mechanism for sepsis-induced myocardial damage remains unclear. Astilbin, a flavonoid, is reported to have anti-inflammatory, antioxidative, and antiapoptotic properties. However, the effects of astilbin on sepsis-induced cardiomyopathy have not been studied so far. This study aims to investigate the effect of astilbin in sepsis-induced myocardial injury and elucidate the underlying mechanism. In vivo and in vitro sepsis models were created using lipopolysaccharide (LPS) as an inducer in H9C2 cardiomyocytes and C57BL/6 mice, respectively. Our results demonstrated that astilbin reduced myocardial injury and improved cardiac function. Moreover, astilbin prolonged the QT and corrected QT intervals, attenuated myocardial electrical remodeling, and promoted gap junction protein (Cx43) and ion channels expression, thereby reducing the susceptibility of ventricular fibrillation. In addition, astilbin alleviated LPS-induced inflammation, oxidative stress, and apoptosis. Astilbin suppressed the toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) pathway in vivo and in vitro models. Astilbin remarkedly upregulated the nuclear factor erythroid 2-related factor 2 (NRF2) and heme oxygenase 1 (HO-1) expression. The in vitro treatment with an NRF2 inhibitor reversed the inhibition of the TLR4/NF-κB pathway and antioxidant properties of astilbin. Astilbin attenuated LPS-induced myocardial injury, cardiac dysfunction, susceptibility to VF, inflammation, oxidative stress, and apoptosis by activating the NRF2/HO-1 pathway and inhibiting TLR4/ NF-κB pathway. These results suggest that astilbin could be an effective and promising therapeutics target for the treatment of sepsis-induced cardiomyopathy.

Recent Advances in the Genetic and Biochemical Mechanisms of Rice Resistance to Brown Planthoppers (Nilaparvata lugens Stål)

Rice (Oryza sativa L.) is the staple food of more than half of Earth's population. Brown planthopper (Nilaparvata lugens Stål, BPH) is a host-specific pest of rice responsible for inducing major losses in rice production. Utilizing host resistance to control N. lugens is considered to be the most cost-effective method. Therefore, the exploration of resistance genes and resistance mechanisms has become the focus of breeders' attention. During the long-term co-evolution process, rice has evolved multiple mechanisms to defend against BPH infection, and BPHs have evolved various mechanisms to overcome the defenses of rice plants. More than 49 BPH-resistance genes/QTLs have been reported to date, and the responses of rice to BPH feeding activity involve various processes, including MAPK activation, plant hormone production, Ca2+ flux, etc. Several secretory proteins of BPHs have been identified and are involved in activating or suppressing a series of defense responses in rice. Here, we review some recent advances in our understanding of rice-BPH interactions. We also discuss research progress in controlling methods of brown planthoppers, including cultural management, trap cropping, and biological control. These studies contribute to the establishment of green integrated management systems for brown planthoppers.