The effects of baicalin and geniposide in combination on microglial activation and 5-lipoxygenase expression in rats during recovery from cerebral ischemia

Background and objectives

This study aimed to analyze the effects of baicalin (BC) and geniposide (GP) in combination (7:3) on the activation of microglia (MG) and 5-lipoxygenase (5-LOX) expression in rats during the recovery period after cerebral ischemia and to determine whether inhibition of the 5-LOX pathway is beneficial for M1-to-M2 polarization of MG.

Methods

Sprague Dawley rats were divided into five groups: control, model, and BC/GP (7:3) at 30, 45, and 60 mg/kg. A permanent middle artery occlusion model was established using the thread embolism method, and recovery after cerebral ischemia was monitored for 5 weeks. The effects on microglial activation and 5-LOX expression were evaluated by the neurofunctional score and immunofluorescence double labeling. The gene expression of 5-LOX in MG was determined by quantitative polymerase chain reaction before and after drug administration. The gene expression of tumor necrosis factor alpha, inducible nitric oxide synthase, interleukin 10, and cluster of differentiation 206 in MG was determined after the administration of zileuton (depressor). Western blotting was performed to determine the protein expression of 5-LOX, cysteinyl leukotriene receptor 1, cysteinyl leukotriene receptor 2, leukotriene B4 receptor 1, and leukotriene B4 receptor 2 before and after the administration of zileuton.

Results

The activation of MG and the expression of 5-LOX were both increased after cerebral ischemia. BC/GP in combination inhibited the activation of microglia-reduced expression of 5-LOX and induced M2 polarization of MG.

Conclusion

The combination of BC and GP downregulates the 5-LOX inflammatory pathway by inhibiting activation of MG and promotes M1-to-M2 polarization of MG. Neurons are protected by the M2-type polarization, resulting in alleviation of cerebral ischemia.

Full text:

https://www.xiahepublishing.com/2835-6357/FIM-2022-00047

The study was recently published in the Future Integrative Medicine.

Future Integrative Medicine (FIM) publishes both basic and clinical research, including but not limited to randomized controlled trials, intervention studies, cohort studies, observational studies, qualitative and mixed method studies, animal studies, and systematic reviews.

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