Comparative Antisickling Activity and Pharmacognostic Characterisation of Spondias mombin Leaf and Stem Bark

Abstract

Aims: This study aims to comparatively evaluate the antisickling activity and pharmacognostic characteristics of the leaves and stem bark of Spondias mombin, with a view to providing scientific evidence for their potential use in sickle cell disease management and establishing diagnostic parameters for their identification and standardisation. Place and Duration of Study: Drug Research and Production Unit, Faculty of Pharmacy, Obafemi Awolowo University, Ile-Ife, Nigeria, between October 2024 and September 2025. Methodology: Dried plant materials were extracted with 70% ethanol, freeze-dried, and reconstituted in phosphate-buffered saline. Inhibitory and reversal antisickling assays were performed on HbSS erythrocytes at concentrations of 2 and 4 mg/mL using sodium metabisulphite-induced sickling. Cytotoxicity was assessed by percentage haemolysis and methaemoglobin (MetHb) formation, while pharmacognostic authentication was performed using standard anatomical procedures. Results: Both extracts demonstrated notable antisickling activity, although their effects varied with concentration and incubation time. SML exhibited higher inhibition at 2 mg/mL in the 4-h batch (47 ± 2.43%) than in the 1-h batch (38 ± 4.11%), while activity at 4 mg/mL was comparable between batches (44 ± 1.97% vs. 44 ± 0.08%). For SMB, inhibition was similar at 2 mg/mL between the 1-h and 4-h batches (33 ± 5.76% vs. 34 ± 2.14%), but markedly higher at 4 mg/mL in the 4-h batch (72 ± 1.32%) than in the 1-h batch (45 ± 4.66%). In reversal assays, SML showed concentration-dependent activity, increasing from approximately 12 ± 4.58% reversal at 2 mg/mL to 58 ± 4.14% at 4 mg/mL, whereas SMB demonstrated approximately 54 ± 5.46% reversal at 2 mg/mL but decreased sharply to about 9 ± 3.24% at 4 mg/mL. Haemolysis values remained below 2% for both extracts across all concentrations tested, indicating low cytotoxicity. MetHb formation increased with concentration, ranging from 4–12% for SML and 8–17% for SMB. Anatomical studies revealed diagnostic features including unicellular trichomes, crystal druses, dorsiventral mesophyll, tannin-containing cells, sclereids, tyloses, and secretory ducts. Conclusion: Spondias mombin leaf and stem bark extracts possess promising antisickling potential with minimal cytotoxicity, supporting their possible development as plant-derived therapeutic agents for sickle cell disease management.