Baicalin attenuates neuronal damage associated with SDH activation and PDK2-PDH axis dysfunction in early reperfusion.

BACKGROUND: Energy deficiency and oxidative stress are interconnected during ischemia/reperfusion (I/R) and serve as potential targets for the treatment of cerebral ischemic stroke. Baicalin is a neuroprotective antioxidant, but the underlying mechanisms are not fully revealed. PURPOSE: This study explored whether and how baicalin rescued neurons against ischemia/reperfusion (I/R) attack by focusing on the regulation of neuronal pyruvate dehydrogenase kinase 2 (PDK2)-pyruvate dehydrogenase (PDH) axis implicated with succinate dehydrogenase (SDH)-mediated oxidative stress. STUDY DESIGN: The effect of the tested drug was explored in vitro and in vivo with the model of oxygen-glucose deprivation/reoxygenation (OGD/R) and middle cerebral artery occlusion/reperfusion (MCAO/R), respectively. METHODS: Neuronal damage was evaluated according to cell viability, infarct area, and Nissl staining. Protein levels were measured by western blotting and immunofluorescence. Gene expression was investigated by RT-qPCR. Mitochondrial status was also estimated by fluorescence probe labeling. RESULTS: SDH activation-induced excessive production of reactive oxygen species (ROS) changed the protein expression of Lon protease 1 (LonP1) and hypoxia-inducible factor-1ɑ (HIF-1ɑ) in the early stage of I/R, leading to an upregulation of PDK2 and a decrease in PDH activity in neurons and cerebral cortices. Treatment with baicalin prevented these alterations and ameliorated neuronal ATP production and survival. CONCLUSION: Baicalin improves the function of the neuronal PDK2-PDH axis via suppression of SDH-mediated oxidative stress, revealing a new signaling pathway as a promising target under I/R conditions and the potential role of baicalin in the treatment of acute ischemic stroke.

Babao Dan alleviates gut immune and microbiota disorders while impacting the TLR4/MyD88/NF-кB pathway to attenuate 5-Fluorouracil-induced intestinal injury.

Adjuvant chemotherapy based on 5-fluorouracil (5-FU), such as FOLFOX, is suggested as a treatment for gastrointestinal cancer. Yet, intestinal damage continues to be a prevalent side effect for which there are no practical prevention measures. We investigated whether Babao Dan (BBD), a Traditional Chinese Medicine, protects against intestinal damage induced by 5-FU by controlling immune response and gut microbiota. 5-FU was injected intraperitoneally to establish the mice model, then 250 mg/kg BBD was gavaged for five days straight. 5-FU led to marked weight loss, diarrhea, fecal blood, and histopathologic intestinal damage. Administration of BBD reduced these symptoms, inhibited proinflammatory cytokine (IL-6, IL-1ß, IFN-γ, TNF-α) secretion, and upregulated the ratio of CD3(+) T cells and the CD4(+)/CD8(+) ratio. According to 16S rRNA sequencing, BBD dramatically repaired the disruption of the gut microbiota caused in a time-dependent way, and increased the Firmicutes/Bacteroidetes (F/B) ratio. Transcriptomic results showed that the mechanism is mainly concentrated on the NF-κB pathway, and we found that BBD reduced the concentration of LPS in the fecal suspension and serum, and inhibited TLR4/MyD88/NF-κB pathway activation. Furthermore, at the genus level on the fifth day, BBD upregulated the abundance of unidentified_Corynebacteriaceae, Aerococcus, Blautia, Jeotgalicoccus, Odoribacter, Roseburia, Rikenella, Intestinimonas, unidentified_Lachnospiraceae, Enterorhabdus, Ruminiclostridium, and downregulated the abundance of Bacteroides, Parabacteroides, Parasutterella, Erysipelatoclostridium, which were highly correlated with intestinal injury or the TLR4/MyD88/NF-κB pathway. In conclusion, we established a network involving 5-FU, BBD, the immune response, gut microbiota, and key pathways to explain the pharmacology of oral BBD in preventing 5-FU-induced intestinal injury.