ABSTRACT
Objective: To investigate the analgesic activity of methanolic extract of Entada phaseoloides (MEEP) along with its molecular mechanistic pathway. Methods: Swiss albino female mice and Wistar rats of either sex were administered orally with MEEP extracts (100, 200 and 400 mg/kg) and pentazocine, tramadol and diclofenac sodium, as standard drugs. Following administration, anti-nociceptive activity was evaluated using an acetic acid-induced writhing test, Eddy’s hot plate, and hot water immersion test. Serum was collected for molecular expression of various proteins and genes using Reverse Transcriptase PCR and Western Blotting. Results: Acetic acid writhing test, a frequently used method to assess peripheral analgesic activity, revealed that MEEP reduced peripherally induced pain in a dose-dependent manner. Likewise, Eddy’s hot plate and hot water immersion methods, often implicated for testing central analgesic activities, showed that MEEP is bestowed with the capability to counteract analgesia in a dose and time-dependent manner. Pro-inflammatory cytokines and factors like COX-2, IL-6, TNF-α, and NF-κB that cause inflammatory responses and pain were significantly reduced, suggesting its analgesic and anti-inflammatory potential. This analgesic and the anti-inflammatory role played by MEEP is also supported by the up-regulation of anti-inflammatory cytokine IL-10 and COMT and COX-1 enzyme demonstrated no significant difference between the groups. Conclusion: The study revealed the weak peripheral and potent central analgesic property MEEP by modulating pro-inflammatory and anti-inflammatory pathways.