Avicenna Journal of Pharmaceutical Research

Background: Nociception is a common feature of neurological disorders. Certain edible seeds contain bioactive phytochemicals with anti-nociceptive features. Buchholzia coriacea seed is traditionally used in folkloric medicine to manage pain-associated ailments. Hence, this study was conducted to assess the therapeutic properties of THE methanol extract of B. coriacea (MEBC) on nociception and its underlying mechanisms in Swiss mice.

Methods: B. coriacea seeds were purchased from the indigenous market in Oje, Ibadan, and authenticated at the Forest Herbarium Ibadan (FHI: 110572). The seeds were pulverized and cold-extracted with methanol. Forty-five male Swiss mice (23-27 g) were divided into nine treatment groups (n=5): control (10 mL/kg), MEBC (50, 100, 200 mg/kg, p.o.), and indomethacin (10 mg/kg, p.o.). Anti-nociceptive activity was evaluated one hour post-administration using the acetic acid-induced writhing test (AAWT), formalin-induced paw licking test (FPLT), and tail flick test (TFT).

Results: The gas chromatography–mass spectrometry (GC-MS) analysis revealed 31 compounds, with linoleic acid being the most abundant. In the mechanistic study, mice were pre-treated with naloxone (1 mg/kg), atropine (2 mg/kg), propranolol (10 mg/kg), or haloperidol (1.5 mg/kg), 15 minutes before MEBC (200 mg/kg) administration. MEBC (50, 100, 200 mg/kg) significantly reduced writhing in the AAWT, inflammatory pain in the FPLT, and increased latency in the TFT. The opiate blocker naloxone (1 mg/kg), cholinergic antagonist atropine (2 mg/kg), beta-adrenergic blocker propranolol (10 mg/kg), and dopamine D2 receptor antagonist haloperidol (1.5 mg/kg) were administered and significantly reversed the anti-nociception effect of MEBC when compared with the 200 mg/kg treatment in the TFT model.

Conclusion: The findings from this study demonstrate that B. coriacea inhibits nociception, which is attributed to the synergistic activity of its bioactive compounds as indicated by the GS-MC. The mechanisms of action are mediate via central nervous system pathways.