Haematinic Effect of Aqueous Justicia carnea Leaf Extract in Healthy Wistar Rats: A 14-day Oral Study

Background: Justicia carnea Lindl. (Acanthaceae) is traditionally used as a blood tonic in Nigeria. Although previous investigations have described its haematological effects in anaemic animal models, evidence concerning the aqueous leaf extract in healthy animals remains limited. Objective: To evaluate the haematological effects of oral administration of aqueous J. carnea leaf extract in healthy male Wistar rats over 14 days. Methods: Twenty-four male Wistar rats were allocated to five groups receiving distilled water (control, n = 4) or aqueous leaf extract at 200, 400, 600 or 800 mg/kg (n = 5 per group). Treatment was administered orally for 14 days. Haematological measurements were available for 14 rats. Haemoglobin concentration was expressed in g/dL, whereas erythrocyte, haematocrit and platelet parameters were normalised to the concurrent control mean. Group differences were evaluated using one-way analysis of variance, Dunnett's test and the Kruskal–Wallis test. Results: Mean haemoglobin concentration was 5.30 ± 1.11 g/dL in controls and 8.73 ± 1.27, 9.95 ± 0.49, 6.37 ± 1.82 and 9.63 ± 2.72 g/dL at increasing extract doses, respectively. Overall differences were observed in haemoglobin (p = 0.043), erythrocyte count (p = 0.041), haematocrit (p = 0.020) and platelet count (p = 0.027). Individual comparisons identified significant differences in selected groups. Mean corpuscular indices showed no significant differences. Conclusion: The aqueous extract was associated with higher erythrocyte-related and platelet measurements at selected doses, suggesting a possible haematinic effect. These findings require confirmation in larger investigations.