An evaluation of the anti-inflammatory, antipyretic and analgesic effects of hydroethanol leaf extract of Albizia zygia in animal models

Abstract

Context: The leaves of Albizia zygia (DC.) J.F. Macbr. (Leguminosae-Mimosoideae) are used in Ghanaian traditional medicine for the treatment of pain, inflammatory disorders and fever (including malaria).

Objectives: The present study evaluated the anti-inflammatory, antipyretic and analgesic effects of the hydroethanol leaf extract of Albizia zygia (AZE) in animal models.

Materials and methods: The anti-inflammatory and antipyretic effects of AZE were examined in the carrageenan-induced foot oedema model and the baker’s yeast-induced pyrexia test respectively. The analgesic effect and possible mechanisms of action were also assessed in the formalin test.

Results: AZE (30–300 mg/kg, p.o.), either preemptively or curatively, significantly inhibited carrageenan-induced foot edema in 7-day-old chicks (ED₅₀ values; preemptive: 232.9 ± 53.33 mg/kg; curative: 539.2 ± 138.28 mg/kg). Similarly, the NSAID diclofenac (10–100 mg/kg, i.p.) significantly reduced the oedema in both preemptive (ED₅₀: 21.16 ± 4.07 mg/kg) and curative (ED₅₀: 44.28 ± 5.75 mg/kg) treatments. The extract (30–300 mg/kg, p.o.) as well as paracetamol (150 mg/kg, p.o.) also showed significant antipyretic activity in the baker’s yeast-induced pyrexia test (ED₅₀ of AZE: 282.5 ± 96.55 mg/kg). AZE and morphine (1–10 mg/kg, i.p.; positive control), exhibited significant analgesic activity in the formalin test. The analgesic effect was partly or wholly reversed by the systemic administration of naloxone, theophylline and atropine.

Conclusion: The results suggest that AZE possesses anti-inflammatory, antipyretic and analgesic properties, which justifies its traditional use. Also, the results show the involvement of the opioidergic, adenosinergic and the muscarinic cholinergic pathways in the analgesic effects of AZE.

Keywords:

• Pyrexia
• pain
• inflammation
• formalin test
• carrageenan
• baker’s yeast

Acknowledgements

We are grateful to the technical staff of the Department of Pharmacology for their assistance. We also thank the following persons: Frederick Dadzie, Samuel Annang Darko, Elsie Serwaa Akoto, Obed Amponsah, Prince Minkah Amankwah Baffour, Modesta Karikari, Esther Akhibi Agbonare, Samuel Papa Yaw and Amoafo David Oppong.

Disclosure statement

The authors report no declarations of interest.