Complanatuside A ameliorates 2,4,6-trinitrobenzene sulfonic acid-induced colitis in mice by regulating the Th17/Treg balance via the JAK2/STAT3 signaling pathway

Immunity imbalance of T helper 17 (Th17)/regulatory T (Treg) cells is involved in the pathogenesis of Crohn's disease (CD). Complanatuside A (CA), a flavonol glycoside, exerts anti-inflammatory activities and our study aimed to identify its effect on TNBS-induced colitis and the possible mechanisms. We found that CA alleviated the symptoms of colitis in TNBS mice, as demonstrated by prevented weight loss and colon length shortening, as well as decreased disease activity index scores, inflammatory scores, and levels of proinflammatory factors. Flow cytometry analysis showed that CA markedly reduced the percentage of Th17 cells while increasing the percentage of Treg cells in TNBS mice. Under Th17 cell polarizing conditions, CA inhibited the differentiation of Th17 cells while the Treg cell differentiation was elevated under Treg cell polarizing conditions. Furthermore, it was observed that JAK2 interacted with CA through six hydrogen bonds via molecular docking. The phosphorylation of JAK2/STAT3 was reduced by CA, which might be correlated with the protective effect of CA on colitis. In conclusion, CA reduced the imbalance of Th17/Treg cells by inhibiting the JAK2/STAT3 signaling pathway in TNBS-induced colitis, which may provide novel strategies for CD treatment.

Complanatuside A improves functional recovery after spinal cord injury through inhibiting JNK signaling-mediated microglial activation

BACKGROUND AND AIMS

Complanatuside A (ComA) is a flavonoid-rich compound in Astragalus membranaceus that has anti-inflammatory and neuroprotective effects. In this study, we focused on the effect of ComA on spinal cord injury (SCI) in mice and explored its possible mechanisms.

METHODS

The SCI model was constructed using C57BL/6J mice, and the effect of ComA on motor function recovery in SCI mice was evaluated through the BMS (Basso Mouse Scale) and footprint test. The histological effects of ComA on SCI mice were evaluated by hematoxylin-eosin (H&E) staining, Luxol-fast blue (LFB) staining, and Nissl staining. In both in vivo and in vitro experiments, we detected the activation of microglia and the release of inflammatory factors through molecular experiments. Immunofluorescence and Western blotting confirmed that ComA can prevent neuronal apoptosis caused by activated microglia through the c-Jun N-terminal kinase (JNK) pathway.

RESULTS

Our research results confirm that ComA can improve motor function in mice after SCI. Our in vitro results indicate that ComA can inhibit the activation of BV2 cells and the release of proinflammatory mediators. In addition, ComA can prevent neuronal cell apoptosis caused by activated BV2 cells. Finally, we found that ComA works through the JNK signaling pathway.

CONCLUSIONS

ComA can accelerate the restoration of motor function in mice after SCI, possibly by reducing neuronal apoptosis via inhibition of JNK-related signaling pathways, a reduction in microglial activation, and inhibition of inflammatory factor release. Our data indicate that ComA is a promising drug candidate for improving functional recovery in patients with SCI.