Effects of Capparis Spinosa extract on the neuropathic pain induced by chronic constriction injury in rats

Neuropathic pain, a chronic pain condition, puts a considerable burden on its patients. However, different pathophysiological characteristics of neuropathic pain make the current treatment medications insufficient in controlling pain. Identifying treatment effects with Capparis Spinosa hydro-alcoholic extract in an animal model of neuropathic pain. Liquid chromatography-mass spectrometry (LC-MS) was used to identify the components of C. Spinosa hydro-alcoholic extract. To establish a neuropathic pain model, adult male Wistar rats underwent chronic constriction injury (CCI) surgery in their left sciatic nerve. Male wistar rats were divided into four groups: CCI, Sham, CCI with C. Spinosa (100 mg/kg), and CCI with C. Spinosa (200 mg/kg). Rats were treated with a hydro-alcoholic extract from aerial parts of the C. Spinosa (orally, daily) starting from CCI induction until 14 days after. Behavioral tests (mechanical allodynia, cold allodynia, and thermal hyperalgesia) and biochemical tests (IL-1 beta, TNF-alpha, MDA, and total thiol) were taken from animals. The LC-MS analysis identified 22 compounds in C. Spinosa extract with the predominance of flavonoids. CCI produced a significant (P < 0.001) increase allodynia (mechanical and cold) and thermal hyperalgesia in comparison with sham group. Oral administration of C. Spinosa significantly (P < 0.05) ameliorated CCI-induced nociceptive pain compared with CCI group. Spinal cord specimens of CCI rats had significant (P < 0.05) elevated inflammation status (up arrow IL-1 beta, up arrow TNF-alpha), and significant (P < 0.05) decreased antioxidative status (up arrow MDA, down arrow total thiol) in comparison with the sham group. These changes were reversed following C. Spinosa treatment. C. Spinosa alleviates neuropathic pain by exhibiting antioxidative and anti-inflammatory effects. The responsible components for these effects are possibly the flavonoid compounds in C. Spinosa extract.