Leucocyte-derived Inflammation Ratios, Red-cell Distribution Width and Platelet Size Indices in Wistar Rats Given Aqueous Justicia carnea Leaf Extract
Asibor, Clara Victory *
Department of Biological Sciences, College of Natural and Applied Sciences, Igbinedion University, Okada, Edo State, Nigeria.
Akpoka, Obhioze Augustine
Department of Biological Sciences, College of Natural and Applied Sciences, Igbinedion University, Okada, Edo State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Background: Ratios derived from the leucocyte differential and the platelet count, together with red-cell and platelet size-distribution indices, are inexpensive markers of systemic inflammation and of the activity of the bone marrow. They have not been applied to Justicia carnea Lindl. (Acanthaceae), a leaf preparation consumed widely in Nigeria as a blood tonic.
Aim: To determine whether repeated oral intake of the aqueous leaf extract alters the leucocyte differential, leucocyte-derived inflammation ratios, red-cell distribution width or platelet size indices in healthy rats.
Methods: Male Wistar rats were given distilled water (n = 4) or the extract at 200, 400, 600 or 800 mg/kg (n = 5 per group) by gavage once daily for 14 days. Blood from 14 rats was analysed on a three-part impedance analyser. Lymphocyte, mid-sized cell (MID) and granulocyte counts and proportions were recorded, and the granulocyte-to-lymphocyte ratio (GLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-MID ratio (LMR) and systemic immune-inflammation index (SII) were calculated. Red-cell distribution width (RDW-CV, RDW-SD), platelet distribution width (PDW), platelet large-cell ratio (P-LCR) and platelet large-cell count (P-LCC) were expressed relative to the control mean. Groups were compared by ANOVA with Dunnett’s test, the Kruskal–Wallis test and a permutation test, with Benjamini–Hochberg adjustment across parameters; dose trends were assessed with the Jonckheere–Terpstra test.
Results: The proportions of lymphocytes (64.3–69.7%) and granulocytes (16.1–24.8%) were unchanged (p = 0.925 and 0.795), and GLR, PLR, LMR and SII did not differ from control (p = 0.324–0.727). Lymphocyte counts were higher in all treated groups (4.30–6.50 vs 2.97 × 10³/µL; Hedges’ g = 0.58–1.99) without reaching significance. RDW did not increase at any dose (RDW-CV 74–92% of control). P-LCC differed between groups (ANOVA p = 0.019; permutation p = 0.022) and was raised at 800 mg/kg (411% of control; Dunnett p = 0.016), whereas PDW was unchanged; this was the only nominally significant result and did not remain significant after adjustment for the 15 parameters tested (adjusted p = 0.284).
Conclusion: The aqueous leaf extract produced no haematological signs of systemic inflammation or disordered erythropoiesis at 200–800 mg/kg. The increase in large platelets at the highest dose, without a change in PDW, suggests stimulated thrombopoiesis rather than platelet activation and warrants confirmation.
Keywords: Justicia carnea, neutrophil-to-lymphocyte ratio, systemic immune-inflammation index, red-cell distribution width, platelet large-cell ratio, Wistar rats