Evaluation of Analgesic, Anti-inflammatory and Antipyretic activities of the Methanol Extract of Crinum jagus Bulb in Rats

Abstract

This study evaluated the analgesic, anti-inflammatory and antipyretic activities of the methanol extract of Crinum jagus bulb. The preliminary phytochemical analysis and acute toxicity studies were carried out following standard procedures. Assessment of analgesic activity in mice was performed using acetic acid-induced writhing and formalin-induced pain tests. Anti-inflammatory and antipyretic activities were performed in rats using egg albumin-induced pedal oedema and Brewer’s yeast-induced pyrexia models respectively. The results of the qualitative phytochemical analysis revealed that the bulb contained alkaloids, flavonoids, steroids, saponins, phenols and terpenoids. The extract was non-toxic; the oral LD was greater than 5000 mgkg-1 at 24 h. The 50 maximal analgesic effect of the extract against acetic acid-induced pain was 47.2% at 400 mgkg-1 compared to 82.2% with aspirin (50 mgkg-1). The extract exerted no significant (p>0.05) analgesic effect different from the control in the first phase (5 min) of formalin-induced pain test. However, there was dose dependent inhibition of pain sensitivity which peaked 85% at 400 mg/kg compared to 94% with piroxicam (500 mgkg-1) in the second phase (15-30 min) of the test indicating a peripherally mediated effect. The lowest test dose (100 mgkg-1) of extract had a comparable oedema inhibition (20%) to aspirin (50 mg/kg). C. jagus bulb extract produced a maximal antipyretic potency (79.5%) at 100 mgkg-1 compared to 83% with paracetamol (50 mgkg-1). Crinum jagus bulb could be a source of potent compounds against pain, inflammation and fever.