Abstract Objectives To investigate the effect of a standardized extract of Centella asiatica (ECa 233), which has anti-inflammatory properties, on the local expression of the transient receptor potential vanilloid 1 (TRPV1), the acid-sensing ion channel subunit 3 (ASIC3), and the calcitonin gene-related peptide (CGRP) in the temporomandibular joint (TMJ) structure 21 days after injecting the TMJ with complete Freund’s adjuvant (CFA). Methodology A mouse model was induced by analyzing the CFA-injected TMJ on days 7, 14, and 21. We assessed TMJ histology by the osteoarthritis cartilage grade score. Then, we observed the effect of different ECa 233 concentrations (30, 100, and 300 mg/kg) and of 140 mg/kg ibuprofen doses on TRPV1, ASIC3, and CGRP local expression on day 21. Results Osteoarthritis cartilage scores were 1.17±0.37 and 3.83±0.68 on days 14 and 21, respectively, in the CFA group (n=5). On day 21, TRPV1, ASIC3, and CGRP expression significantly increased in the CFA group. In the ibuprofen-treated group, TRPV1 expression significantly decreased, but ASIC3 and CGRP showed no significant difference. All ECa 233 doses reduced TRPV1 expression, but the 100 mg/kg ECa 233 dose significantly decreased ASIC3 expression. Conclusions TRPV1, ASIC3, and CGRP expression increased in mice with TMJ-OA on day 21. All ECa 233 and ibuprofen doses inhibited pathogenesis by modulating the local expression of TRPV1 and ASIC3. Therefore, ECa 233 was more effective than ibuprofen.

SUMMARY: Cisplatin is an antineoplastic agent with neuropathy as one of its major side effect. However, effective treatment is lacking. Increasing evidence suggests that cisplatin might damage nerve capillaries leading to impaired functions of blood-nerve barrier (BNB) and neuropathy. This study was aimed to examine the effects of cisplatin on pericytes. Rats were either treated with intraperitoneal injection of cisplatin 2 mg/kg twice a week for five continuous weeks. Cisplatin-treated rats showed reduced body weight, thermal hypoalgesia and slow sciatic motor nerve conduction velocity, indicating neuropathy. The density of pericytes in the distal sciatic nerves determined by immunohistochemistry to desmin was significantly reduced in the cisplatin compared with that of the control groups. Electron microscopic analysis demonstrated the detachment of pericytes from endothelial cells including the disruption of shared basement membrane in the sciatic nerves from cisplatin-treated rats. These data indicate the pericyte loss and detachment caused by cisplatin. Future studies of the BNB components and functions after cisplatin treatment are needed and will be essential for the development of effective treatments against cisplatin-induced neuropathy.

RESUMEN: El cisplatino es un agente antineoplásico y presenta como uno de sus principales efectos secundarios, la neuropatía. Sin embargo, falta un tratamiento eficaz. La creciente evidencia sugiere que el cisplatino podría dañar los capilares nerviosos, lo que puede provocar una alteración de las funciones de la barrera hematoencefálica (BHE) y neuropatía. Este estudio tuvo como objetivo examinar los efectos del cisplatino en los pericitos. Las ratas se trataron con inyección intraperitoneal de cisplatino (2 mg/kg) dos veces por semana durante 5 semanas seguidas. Las ratas tratadas con cisplatino mostraron una reducción del peso corporal, hipoalgesia térmica y una velocidad de conducción del nervio ciático lenta, lo que indicaría neuropatía. La densidad de los pericitos en los nervios ciáticos distales determinada por inmunohistoquímica para desmina se redujo significativamente en el grupo cisplatino en comparación con la de los grupos controles. El análisis al microscopio electrónico demostró el desprendimiento de pericitos de las células endoteliales, incluida la ruptura de la membrana basal compartida en los nervios ciáticos de ratas tratadas con cisplatino. Estos datos indican la pérdida de pericitos y el desprendimiento causado por el cisplatino. Se necesitan estudios futuros de los componentes y funciones del BHE después del tratamiento con cisplatino y serán esenciales para el desarrollo de tratamientos efectivos contra la neuropatía inducida por el cisplatino.