[UPLC-Q-TOF-MS metabolomic study on improvement of acute myocardial ischemia in rats by Dalbergia cochinchinensis heartwood].

This paper aimed to study the effect of Dalbergia cochinchinensis heartwood on plasma endogenous metabolites in rats with ligation of the left anterior descending coronary artery, and to analyze the mechanism of D. cochinchinensis heartwood in improving acute myocardial ischemic injury. The stability and consistency of the components in the D. cochinchinensis heartwood were verified by the establishment of fingerprint, and 30 male SD rats were randomly divided into a sham group, a model group, and a D. cochinchinensis heartwood(6 g·kg~(-1)) group, with 10 rats in each group. The sham group only opened the chest without ligation, while the other groups established the model of ligation. Ten days after administration, the hearts were taken for hematoxylin-eosin(HE) staining, and the content of heart injury indexes in the plasma creatine kinase isoenzyme(CK-MB) and lactate dehydrogenase(LDH), energy metabolism-related index glucose(Glu) content, and vascular endothelial function index nitric oxide(NO) was determined. The endogenous metabolites were detected by ultra-high-performance liquid chromatography-time-of-flight-mass spectrometry(UPLC-Q-TOF-MS). The results showed that the D. cochinchinensis heartwood reduced the content of CK-MB and LDH in the plasma of rats to relieve myocardial injury, reduced the content of Glu in the plasma, improved myocardial energy metabolism, increased the content of NO, cured the vascular endothelial injury, and promoted vasodilation. D. cochinchinensis heartwood improved the increase of intercellular space, myocardial inflammatory cell infiltration, and myofilament rupture caused by ligation of the left anterior descending coronary artery. The metabolomic study showed that the content of 26 metabolites in the plasma of rats in the model group increased significantly, while the content of 27 metabolites decreased significantly. Twenty metabolites were significantly adjusted after the administration of D. cochinchinensis heartwood. D. cochinchinensis heartwood can significantly adjust the metabolic abnormality in rats with ligation of the left anterior descending coronary artery, and its mechanism may be related to the regulation of cardiac energy metabolism, NO production, and inflammation. The results provide a corresponding basis for further explaining the effect of D. cochinchinensis on the acute myocardial injury.

UPLC-Q-TOF-MS metabolomic study on improvement of acute myocardial ischemia in rats by Dalbergia cochinchinensis heartwood / 中国中药杂志

This paper aimed to study the effect of Dalbergia cochinchinensis heartwood on plasma endogenous metabolites in rats with ligation of the left anterior descending coronary artery, and to analyze the mechanism of D. cochinchinensis heartwood in improving acute myocardial ischemic injury. The stability and consistency of the components in the D. cochinchinensis heartwood were verified by the establishment of fingerprint, and 30 male SD rats were randomly divided into a sham group, a model group, and a D. cochinchinensis heartwood(6 g·kg~(-1)) group, with 10 rats in each group. The sham group only opened the chest without ligation, while the other groups established the model of ligation. Ten days after administration, the hearts were taken for hematoxylin-eosin(HE) staining, and the content of heart injury indexes in the plasma creatine kinase isoenzyme(CK-MB) and lactate dehydrogenase(LDH), energy metabolism-related index glucose(Glu) content, and vascular endothelial function index nitric oxide(NO) was determined. The endogenous metabolites were detected by ultra-high-performance liquid chromatography-time-of-flight-mass spectrometry(UPLC-Q-TOF-MS). The results showed that the D. cochinchinensis heartwood reduced the content of CK-MB and LDH in the plasma of rats to relieve myocardial injury, reduced the content of Glu in the plasma, improved myocardial energy metabolism, increased the content of NO, cured the vascular endothelial injury, and promoted vasodilation. D. cochinchinensis heartwood improved the increase of intercellular space, myocardial inflammatory cell infiltration, and myofilament rupture caused by ligation of the left anterior descending coronary artery. The metabolomic study showed that the content of 26 metabolites in the plasma of rats in the model group increased significantly, while the content of 27 metabolites decreased significantly. Twenty metabolites were significantly adjusted after the administration of D. cochinchinensis heartwood. D. cochinchinensis heartwood can significantly adjust the metabolic abnormality in rats with ligation of the left anterior descending coronary artery, and its mechanism may be related to the regulation of cardiac energy metabolism, NO production, and inflammation. The results provide a corresponding basis for further explaining the effect of D. cochinchinensis on the acute myocardial injury.

Neutralizing antibody evasion and receptor binding features of SARS-CoV-2 Omicron BA.2.75

Recently emerged SARS-CoV-2 Omicron subvariant, BA.2.75, displayed a local growth advantage over BA.2.38, BA.2.76 and BA.5 in India. The underlying mechanism of BA.2.75s enhanced infectivity, especially compared to BA.5, remains unclear. Here, we show that BA.2.75 exhibits substantially higher ACE2-binding affinity than BA.5. Also, BA.2.75 spike shows decreased thermostability and increased "up" RBD conformation in acidic conditions, suggesting enhanced low-pH-endosomal cell-entry pathway utilization. BA.2.75 is less humoral immune evasive than BA.4/BA.5 in BA.1/BA.2 breakthrough-infection convalescents; however, BA.2.75 shows heavier neutralization evasion in Delta breakthrough-infection convalescents. Importantly, plasma from BA.5 breakthrough infection exhibit significantly weaker neutralization against BA.2.75 than BA.5, mainly due to BA.2.75s distinct RBD and NTD-targeting antibody escaping pattern from BA.4/BA.5. Additionally, Evusheld and Bebtelovimab remain effective against BA.2.75, and Sotrovimab recovered RBD-binding affinity. Together, our results suggest BA.2.75 may prevail after the global BA.4/BA.5 wave, and its increased receptor-binding capability could allow further incorporation of immune-evasive mutations.