Therapeutic Effects of Gualou Guizhi Antispasmodic Granules on Spasticity and PANoptosis in a Rat Model of Spinal Cord Injury

Muscle spasticity after spinal cord injury (SCI) severely impacts quality of life, with limited effective treatments. Gualou Guizhi Antispasmodic Granules (GLGZ), a hospital-developed traditional Chinese medicine (TCM) formulation, can relieve spasms. This study aimed to assess GLGZ's efficacy in SCI-induced spasticity and its association with PANoptosis (a novel programmed cell death involving apoptosis, necroptosis, and pyroptosis). Male Sprague-Dawley rats weighing 180-200 g were used. SCI was induced via the Allen weight-drop method. The successful model rats were randomly assigned to a model group or one of the GLGZ dose groups: high, medium, or low. Sham rats underwent laminectomy without spinal cord injury. Interventions lasted 4 weeks. After the intervention, limb motor function was evaluated using the Basso-Beattie-Bresnahan (BBB) scale. Femoral muscle stiffness was assessed via ultrasound shear wave elastography (SWE), while spinal cord integrity was determined with magnetic resonance imaging (MRI). Hematoxylin-eosin (HE), Nissl, and Luxol fast blue staining were performed to observe histopathological alterations. Multiplex immunofluorescence staining was used to label apoptosis-associated speck-like protein containing a CARD (ASC, green), Caspase-8 (orange), and receptor-interacting serine/threonine-protein kinase 3 (RIPK3, yellow) to assess PANoptosis. GLGZ improved BBB scores dose-dependently: sham (21.00 ± 0.00), model (5.8 ± 1.1), high-dose (10.6 ± 1.3), medium-dose (8.5 ± 1.2), low-dose (7.1 ± 1.0). SWE showed reduced muscle stiffness: model (6.68 ± 0.74 m/s), high-dose (2.19 ± 0.36 m/s, P < 0.001), medium-dose (3.04 ± 0.45 m/s, P = 0.002), low-dose (4.08 ± 0.65 m/s, P = 0.031) vs model. As compared with the model group (3.65 ± 1.03 mm²), GLGZ dose-dependently reduced the spinal cord lesion size in all dosage groups (all P < 0.05), (1.33 ± 0.79 mm² in high-dose, 1.94 ± 0.67 mm² in medium-dose, 2.50 ± 0.79 mm² in low-dose group. Histology revealed GLGZ preserved neurons and promoted myelin repair. GLGZ dose-dependently reduced ASC, Caspase-8, and RIPK3 expression.