Evaluation of Phytochemical, Antioxidant, Anti-sickling, and Membrane Stabilization Properties of Justicia carnea Leaves and Stems Extracts

Introduction: Sickle cell disease (SCD) is an autosomal recessive inherited genetic blood disorder resulting from the aberrant structure of hemoglobin (Hb) that results in the production of hemoglobin S (Hb S). Objective: This study aimed to investigate the phytochemical profiles, antioxidant, anti-sickling, and membrane stabilizing activities of crude extracts of Justicia carnea leaves and stems that used to treat SCD in Nigeria. Methods: The 70 % ethanol crude extracts of the dried, powdered leaves and stems of J. carnea were prepared by maceration. Reversal and inhibition activity of the plant materials were evaluated by using sodium-metabisulphite-sickled HB SS blood cells from two patients not in crisis. The membrane stabilization assays on rats' red blood cells (RBCs) and human sickled RBCs and antioxidant assays were determined following standard methods. Results were presented as Mean ± SEM. Data analysis and graph plotting were carried out using GraphPad Prism® version 8.01. Results: The antioxidant assays indicated that J. carnea leaves (JCL) had stronger DPPH activity (IC₅₀ = 245.031 ± 0.228 μg/mL). While, the stems (JCS) exhibited higher NO scavenging (84.123 ± 0.497 μg/mL). The highest reversal and inhibition percentages observed at 60, 90, and 120-minute time points. At 60th minutes reading, JCL 20 mg/mL (78.9±0.13%) demonstrated the highest reversal activity, while JCL 10 mg/mL (66.9±0.82 %) revealed the strongest inhibition effect. The extracts showed dose-dependent membrane stabilization activity. Conclusions: The extracts demonstrated remarkable antioxidant, anti-sickling, and membrane stabilizing activities. The use of this plant could be a promising natural therapy for SCD.