Dynamic changes of MMPs during cerebral aneurysm formation in rats and the effect of resveratrol on MMP expression.

Objectives: To investigate the expression of matrix protein metalloenzymes (MMPs) during cerebral aneurysm (CA) formation and assess the effects of resveratrol (RES) on MMP expression and CA prevention.

Methods: Male Sprague-Dawley rats were randomly divided into three groups: sham-operated, CA, and RES groups. CA models were constructed by ligating the renal and carotid arteries of SD rats. The RES group received a diet mixed with RES (50 mg/kg), while the CA group was given normal feed; the sham-operated group underwent simulated surgery without ligation and received normal feed. HE staining was used to observe the pathological changes in the cerebral artery aneurysm wall. Immunofluorescence (IF) staining and RT-PCR were used to detect the expression of MMP-2 and MMP-9, as well as oxidative stress markers in the cerebral artery wall tissues of rats at 1-, 2-, and 3-months post-surgery.

Results: HE staining reveled that after ligation, the cerebral artery walls of SD rats exhibited irregular thickness, twisted morphology, abnormal nuclear morphology of the cells, and infiltration of inflammatory cells, confirming the successful establishment of CA model. Meanwhile, the infrared spectrogram of the RES purified from Tiger Balm closely matched that of the standard, confirming successful purification. IF staining indicated that MMP-2 and MMP-9 levels dynamically increased over time in the vessel wall of the CA rats. Subsequently, antioxidant assays showed that RES treatment enhanced antioxidant capacity, with increased levels of superoxide dismutase, glutathione peroxidase, and catalase in the vascular wall tissue. Moreover, after 3 months of RES treatment, IF staining showed a marked reduction in MMP-2 and MMP-9 levels in the vessel walls of CA rats. Meanwhile, HE staining also showed improvements in the wall structure, with a more intact wall and an increased vascular endothelial cell density.

Conclusions: RES effectively inhibits the expression of MMP-2 and MMP-9, thereby preventing and delaying the development of CA.