AKBA Promotes Axonal Regeneration via RhoA/Rictor to Repair Damaged Sciatic Nerve

Acetyl-11-keto-beta-boswellic acid modulates macrophage polarization and Schwann cell migration to accelerate spinal cord injury repair in rats

BACKGROUND

Inhibiting secondary inflammatory damage caused by glial cells and creating a stable microenvironment is one of the main strategies to investigate drugs for the treatment of spinal cord injury. Acetyl-11-keto-beta-boswellic acid (AKBA) is the active component of the natural drug boswellia, which has anti-inflammatory and antioxidant effects and offers a possible therapeutic option for spinal cord injury.

METHODS

In this study, a spinal cord injury model was established by crushing spinal cord, respectively, to detect the M1 macrophage inflammatory markers: iNOS, TNF-α, IL-1β, and the M2 macrophage markers CD206, ARG-1, IL-10, and the detection of antioxidant enzymes and MDA. In vitro, macrophages were cultured to verify the main mechanism of the macrophage switch from Nrf2/HO-1 to M2 type by flow cytometry, immunofluorescence, and other techniques. Macrophage and Schwann cell co-culture validated the migration mechanism of Schwann cells promoted by AKBA.

RESULTS

AKBA significantly enhanced the antioxidant enzyme activities of CAT, GSH-Px, T-AOC, and SOD, reduced MDA content, and reduced oxidative damage caused by spinal cord injury via the Nrf2/HO-1 signaling pathway; AKBA mediates Nrf2/HO-1/IL-10, converts macrophages from M1 to M2 type, reduces inflammation, and promotes Schwann cell migration, thereby accelerating the repair of spinal cord injury in rats.

CONCLUSIONS

Our work demonstrates that AKBA can attenuate oxidative stress as well as the secondary inflammatory injury caused by macrophages after SCI, promote Schwann cell migration to the injury site, and thus accelerate the repair of the injured spinal cord.

Acetyl-11-Keto-β-Boswellic Acid Accelerates the Repair of Spinal Cord Injury in Rats by Resisting Neuronal Pyroptosis with Nrf2

The primary aim of this study is to delve into the potential of Acetyl-11-keto-β-boswellic acid (AKBA) in ameliorating neuronal damage induced by acute spinal cord injury, as well as to unravel the intricate underlying mechanisms. A cohort of 40 Sprague-Dawley rats was meticulously categorized into four groups. Following a seven-day oral administration of AKBA, damaged spinal cord samples were meticulously procured for Nissl staining and electron microscopy to assess neuronal demise. Employing ELISA, immunofluorescence, Western blot (WB), and quantitative polymerase chain reaction (qPCR), the modulatory effects of AKBA within the context of spinal cord injury were comprehensively evaluated. Furthermore, employing an ex vivo extraction of spinal cord neurons, an ATP + LPS-induced pyroptotic injury model was established. The model was subsequently subjected to Nrf2 inhibition, followed by a battery of assessments involving ELISA, DCFH-DA staining, flow cytometry, immunofluorescence, and WB to decipher the effects of AKBA on the spinal cord neuron pyroptosis model. By engaging the Nrf2-ROS-NLRP3 pathway, AKBA exerted a repressive influence on the expression of the pyroptotic initiator protein Caspase-1, thereby mitigating the release of GSDMD and alleviating pyroptosis. Additionally, AKBA demonstrated the ability to attenuate the release of IL-18 and IL-1β, curbing neuronal loss and expediting the restorative processes within the context of spinal cord injury. Our study elucidates that AKBA can reduce spinal cord neuronal apoptosis, providing a basis for the development of AKBA as a clinical treatment for spinal cord injury.