Phytochemical Investigation and Anti-Inflammatory Evaluation of Isolated Compounds from the Stems of Mimosa hamata (Willd.)

Abstract: Background: Inflammation underlies the pathogenesis of a wide range of acute and chronic human diseases. Long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) and opioid analgesics is limited by gastric, renal and dependence-related adverse effects, prompting continued interest in plant-derived anti-inflammatory agents. Mimosa hamata (Willd.) (Mimosaceae) is used traditionally for urinary complaints, glandular swellings and as a general tonic, but its anti-inflammatory potential has not been previously characterized. Objective: To evaluate the acute and chronic anti-inflammatory activity of a bioactive fraction (Fraction IV) and two isolated compounds (Compound I and Compound II) obtained from the ethanolic extract of the stems of M. hamata (ESMH). Methods: Preliminary phytochemical screening of ESMH was performed. Acute anti-inflammatory activity was assessed using the carrageenan-induced rat paw oedema model, and chronic anti-inflammatory activity was assessed using the cotton pellet-induced granuloma model in Wistar albino rats. Aceclofenac (10 mg/kg) served as the reference standard. Paw volume and granuloma weight were compared across groups using one-way ANOVA followed by Dunnett's multiple comparison test. Results: Preliminary phytochemical screening revealed the presence of Flavonoids, Carbohydrates, Glycosides And Tannins in ESMH. In the carrageenan model, Fraction IV (40 mg/kg) produced the greatest oedema inhibition among the test groups (84.09% at 5 h), followed by Compound I (64.77%) and Compound II (59.66%), compared with Aceclofenac (70.45%). In the cotton pellet granuloma model, Compound I produced the highest inhibition of granuloma dry weight (50.25%), followed by Compound II (45.94%) and ESMH (38.97%), compared with Aceclofenac (57.33%). Conclusion: The bioactive fraction and isolated compounds from the stems of M. hamata exhibit significant acute and chronic anti-inflammatory activity, plausibly mediated by their flavonoid content. These findings support further mechanistic and phytochemical characterisation of M. hamata as a source of anti-inflammatory lead compounds. Keywords: Mimosa hamata; anti-inflammatory activity; carrageenan-induced paw oedema; cotton pellet granuloma; flavonoids