Ethnopharmacological validation of Terminalia superba (Combretaceae) as an anti-inflammatory agent: An integrated in vitro and in vivo assessment.

Abstract

ETHNOPHARMACOLOGICAL RELEVANCE: Terminalia superba is used in Nigerian traditional medicine to treat inflammation, yet its solvent fractions have not been fully evaluated using diverse mechanistic and in vivo inflammation models. AIM: To evaluate and compare the anti-inflammatory potential of the crude methanol extract (METs) and its solvent fractions (HFTs, EFTs, BFTs) of T. superba, and to explore mechanistic links between in vitro assays and in vivo efficacy. MATERIALS AND METHODS: METs was fractionated into n-hexane (HFTs), ethyl acetate (EFTs), and butanol (BFTs). Qualitative phytochemical screening was carried out. In vitro anti-inflammatory activities were assessed using hypotonic and heat-induced erythrocyte membrane stabilization assays and the egg albumin denaturation test. In vivo, formalin-induced paw edema, xylene-induced ear edema, and carrageenan-induced peritonitis models were used. Multivariate analyses, including hierarchical clustering, principal component analysis, and canonical correlation analysis, were applied. RESULTS: Phytochemical profiling showed enrichment of nonpolar bioactives in HFTs, while flavonoids dominated in BFTs. HFTs at 400 μg/mL inhibited 44.8 % hemolysis under hypotonic stress, and 50.6 % under heat-induced stress; albumin denaturation was inhibited by 64.9 %. In vivo, METs and HFTs at 400 mg/kg significantly reduced paw edema to levels similar to piroxicam; HFTs strongly inhibited xylene-ear edema; and leukocyte migration in peritonitis was suppressed by 50 % with HFTs. Multivariate clustering distinctly separated high-dose METs and HFTs from other fractions; canonical correlation indicated alignment between in vitro protein protection and in vivo leukocyte inhibition. CONCLUSION: This study validates the ethnopharmacological use of T. superba, particularly its n-hexane-rich fraction (HFTs), as a potent anti-inflammatory agent with consistent effects in mechanistic and animal models. HFTs merit further isolation, mechanistic elucidation, and development toward phytopharmaceutical use.