Buchholzia coriacea Seed Methanol Extract Represses Nociception via Central Pathway Mechanisms in Swiss Mice

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: ۱۱۰۵۷۲). The seeds were pulverized and cold-extracted with methanol. Forty-five male Swiss mice (۲۳-۲۷ g) were divided into nine treatment groups (n=۵): control (۱۰ mL/kg), MEBC (۵۰, ۱۰۰, ۲۰۰ mg/kg, p.o.), and indomethacin (۱۰ 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 ۳۱ compounds, with linoleic acid being the most abundant. In the mechanistic study, mice were pre-treated with naloxone (۱ mg/kg), atropine (۲ mg/kg), propranolol (۱۰ mg/kg), or haloperidol (۱.۵ mg/kg), ۱۵ minutes before MEBC (۲۰۰ mg/kg) administration. MEBC (۵۰, ۱۰۰, ۲۰۰ mg/kg) significantly reduced writhing in the AAWT, inflammatory pain in the FPLT, and increased latency in the TFT. The opiate blocker naloxone (۱ mg/kg), cholinergic antagonist atropine (۲ mg/kg), beta-adrenergic blocker propranolol (۱۰ mg/kg), and dopamine D۲ receptor antagonist haloperidol (۱.۵ mg/kg) were administered and significantly reversed the anti-nociception effect of MEBC when compared with the ۲۰۰ 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.