Tubuloside B Alleviates Aβ25-35 Induced PC12 Cell Injury by Attenuating Pyroptosis, Apoptosis and Excessive Autophagy
摘要
Cistanche, a traditional Chinese medicine with reported neuroprotective effects, contains multiple bioactive constituents whose specific mechanisms of action remain incompletely defined. Here, we aimed to identify a key neuroprotective component and explore its potential mechanism against Aβ-induced neurotoxicity. Fourteen commercially available Cistanche-derived compounds were screened for neuroprotection in an Aβ25-35 (Aβ fragment 25–35)-injured PC12 cell model. The most active compound, Tubuloside B (TB), was further investigated using polymerase chain reaction (PCR) array, immunoblotting, flow cytometry, immunofluorescence, and mitochondrial function assays. TB exerted concentration-dependent protective effects in the Aβ25-35-injured PC12 model. Aβ25-35 exposure was associated with marked activation of pyroptotic signaling, characterized by caspase-1 activation, GSDMD cleavage, and increased interleukin (IL)-1β/IL-18 levels. These alterations were substantially blunted in the presence of TB. Modulation of the absent in melanoma 2 (AIM2) inflammasome pathway was further supported by reduced AIM2 expression and diminished apoptosis-associated speck-like protein containing a CARD (ASC) speck formation. Mitochondrial perturbations induced by Aβ25-35, including excessive mitochondrial reactive oxygen species (ROS) generation, membrane depolarization, and cytosolic mtDNA accumulation, were concurrently ameliorated by TB. In addition, markers of apoptosis and dysregulated autophagy were partially normalized following TB treatment. These findings suggest that TB may contribute to neuroprotection in an Aβ25-35-induced PC12 cell model, potentially involving modulation of mitochondrial dysfunction–associated inflammasome activation and downstream cell death pathways. Given the in vitro design and limited sample size, these results should be considered preliminary and warrant further validation in vivo.