Caraway Oil as a Multimodal Therapy for Neuropathic Pain: Investigating the Mechanisms of Action in Rats with Chronic Constriction Injury

Abstract

Neuropathic pain, a prevalent concern associated with various pathological conditions, poses a significant public health risk due to its poorly understood pathophysiology and treatment complexities. Multimodal therapy is often the most efficacious approach to managing neuropathic pain, yet it is also highly labour intensive. The exact underlying causes of neuropathic pain are unclear; evidence suggests that cytokines, neuropeptides, and neurotrophic factors may play a role in its pathogenesis. The current study aimed to investigate the anti-neuropathic pain activity of caraway oil and the molecular mechanisms underlying its actions in rats with CCI, a model of neuropathic pain. Behavioural evaluations of cold allodynia, heat hyperalgesia, mechanical allodynia, and mechanical hyperalgesia were conducted using the acetone spray test, hot plate test, Von Frey hair test, and pinprick test, respectively. Additionally, the level of TNF-α in the sciatic nerve was examined as an indicator of inflammation, and NGF and substance P levels were determined in the DRG to identify mechanistic processes. Rats were administered caraway oil orally at doses of 25 and 50 mg/kg for 21 days. Results indicated that caraway oil administration significantly reduced behaviour associated with injury-related pain and elevated TNF levels. After an anti-NGF injection on the 21st day, significant attenuated behavioural effects were observed. Furthermore, caraway oil administration was able to inhibit the upregulation of NGF in DRG caused by CCI and minimize the increase in substance P in DRG. These findings suggest that caraway oil has promising therapeutic potential for managing neuropathic pain by targeting peripheral and secondary sensitization mechanisms.

Keywords

• neuropathic pain
• chronic constriction injury
• substance P
• nerve growth factor
• sciatic nerve ligation
• caraway oil