Protective Effect of Justicia carnea Leaf Extract Against Cyclophosphamide-Induced Megaloblastic Anaemia in Rats: An Experimental Study

Abstract

Megaloblastic anaemia is a frequent haematological complication of cytotoxic chemotherapy, and safe adjunctive agents are needed. Justicia carnea Lindl. (Acanthaceae) is widely used in Nigerian folk medicine as a “blood tonic”, but its effect on megaloblastic anaemia has not been characterised. To evaluate the protective effect of the ethanol leaf extract of J. carnea against cyclophosphamide-induced megaloblastic anaemia in rats. Qualitative and quantitative phytochemical screening and acute oral toxicity testing (Lorke’s method) were performed. Rats were allocated to five groups: normal control; cyclophosphamide 30 mg/kg; and extract at 250, 500 or 1000 mg/kg plus cyclophosphamide 30 mg/kg. Treatments were administered orally every 48 h for 28 days. Body weight, serum folate (vitamin B₉) and cobalamin (vitamin B₁₂), haematological indices, erythrocyte osmotic fragility, relative liver weight, liver function markers, antioxidant status and pro-inflammatory cytokines (IL-1β, TNF-α) were assessed. The extract was rich in phenols (22.52±0.25), flavonoids (15.86±0.12) and saponins (12.04±0.08), and its oral LD₅₀ exceeded 5000 mg/kg. Cyclophosphamide reduced RBC count, haemoglobin and PCV by 53.7%, 46.8% and 38.6%, respectively, increased MCV by 32.8%, and lowered serum vitamin B₉ and B₁₂ by 60.4% and 56.7%. The extract attenuated these changes dose-dependently: at 1000 mg/kg, vitamin B₉ rose from 1.63±0.03 to 3.21±0.04 and vitamin B₁₂ from 2.83±0.03 to 5.98±0.07 (p≤0.05), while MCV fell to 66.43±0.08 fl. Median corpuscular fragility decreased from 0.638% to 0.490% NaCl; MDA, IL-1β, TNF-α and aminotransferase activities decreased, whereas SOD, CAT, GPx and GSH recovered towards control values. J. carnea leaf extract provides dose-dependent haematological, membrane-stabilising, hepatoprotective, antioxidant and anti-inflammatory protection in cyclophosphamide-induced megaloblastic anaemia, supporting its traditional use and further development as an adjunctive phytotherapeutic agent.