Lamotrigine Reduces Visceral Nociception and Peritoneal Inflammation in Mice

AIM: Visceral pain is a complex type of pain originating from internal organs and often difficult to localize, occurring in many acute and chronic diseases. Lamotrigine is an antiepileptic drug that reduces glutamate release by inhibiting voltage-sensitive sodium and calcium channels. The aim of this study was to evaluate the analgesic and anti-inflammatory effects of lamotrigine in an acetic acid-induced visceral pain model.
MATRERIAL and METHOD: 24 adult male BALB/c mice were divided into four groups, with six animals per group: Control (Con), acetic
acid (AA), lamotrigine (LTG), and acetic acid + lamotrigine (AA+LTG). Writhing behavior was counted for 15 minutes after i.p. injection of acetic acid, and an open-field test was performed one hour later to assess locomotor activity. At the end of the experiment, the animals were sacrificed, and their peritoneal tissues were subjected to histopathological examination. p<0.05 was considered statistically significant.
RESULTS: The increased number of writhes in the AA group (Mdn= 35, IQR= 23.5–38) was significantly reduced by LTG administration (Mdn= 0, IQR= 0–1.5). No significant difference was observed in the mean velocities between the Con and AA+LTG groups. Acetic acid administration was found to cause significant cellular infiltration in the peritoneal tissue, while lamotrigine largely prevented this cellular infiltration, providing a protective effect.
CONCLUSION: The results of our study demonstrated that lamotrigine has a significant antinociceptive effect on visceral pain. Consistent with these results, histopathological examinations revealed that lamotrigine significantly inhibited inflammatory cell infiltration. These findings suggest that lamotrigine may be considered a potential therapeutic agent in the management of visceral pain.