Chemical characterization of extracts of leaves of Kadsua coccinea (Lem.) A.C. Sm. by UHPLC-Q-Exactive Orbitrap Mass spectrometry and assessment of their antioxidant and anti-inflammatory activities.

Kadsua coccinea (K. coccinea) has long been used as a fruit and folk medicine; however, the composition of its leaves and the activities of its constituents have been seldom studied. A total of 98 chemical constituents, including 53 phenolic acids, 41 flavonoids, and 4 lignans, were identified from the plant of kadsua coccinea by UHPLC-Q-Exactive Orbitrap Mass spectrometry. All these chemicals were reported for the first time in leaves, and 95 of them have been reported for the first time in the plant of kadsua coccinea. The biological potential of extracts of K. coccinea leaves (EKL) was evaluated by in vitro antioxidant assay and anti-inflammatory assay. EKL are composed of polysaccharides (60%), polyphenols (26%), and proteins (11%). EKL present decent potent •OH and DPPH scavenging abilities and Fe2+ chelating ability. They also inhibit the secretion of NO, reduce the level of Cox2 in proteins, inhibit the secretion of pro-inflammatory cytokines, such as IL-2 and IL-6, and promote the secretion of anti-inflammatory cytokine IL-10. These results displayed significant antioxidant and anti-inflammatory activities of EKL, which will be very beneficial for further development and investigation of kadsua coccinea leaves.

A Mouse Model of Enterovirus D68 Infection for Assessment of the Efficacy of Inactivated Vaccine.

In recent years, enterovirus D68 (EVD68) has been reported increasingly to be associated with severe respiratory tract infections and acute flaccid myelitis (AFM) in children all over the world. Yet, no effective vaccines or antiviral drugs are currently available for EVD68. Although several experimental animal models have been developed, immunogenicity and protective efficacy of inactivated EVD68 vaccines has not been fully evaluated. To promote the development of vaccines, we established an Institute of Cancer Research (ICR) suckling mouse model of EVD68 infection in this study. The results showed that ICR neonatal mice up to about nine days of age were susceptible to infection with EVD68 clinical strain US/MO/14-18947 by intraperitoneal injection. The infected mice exhibited progressive limb paralysis prior to death and the mortality of mice was age- and virus dose-dependent. Tissue viral load analysis showed that limb muscle and spinal cord were the major sites of viral replication. Moreover, histopathologic examination revealed the severe necrosis of the limb and juxtaspinal muscles, suggesting that US/MO/14-18947 has a strong tropism toward muscle tissues. Additionally, ß-propiolactone-inactivated EVD68 vaccine showed high purity and quality and induced robust EVD68-specific neutralizing antibody responses in adult mice. Importantly, results from both antisera transfer and maternal immunization experiments clearly showed that inactivated EVD68 vaccine was able to protect against lethal viral infection in the mouse model. In short, these results demonstrate the successful establishment of the mouse model of EVD68 infection for evaluating candidate vaccines against EVD68 and also provide important information for the development of inactivated virus-based EVD68 vaccines.