Immunostimulatory and Other Haematological Effects of Long Term Administration of Aqueous Leaf Extract of Carica Papaya Linn. (Caricaceae) Extracts to Normal Rabbits

Abstract

Carica papaya Linn. (Caricaceae)is used traditionally to treat malaria, hypertension, sickle cell anemia and diabetes. Its long-term hypoglycaemic and anti-obesity effects in normal rabbits are documented. This study assessed the long term immunostimulatory and other haematological effects of aqueous C. papaya leaf extract administered orally to normal rabbits at 200 mg/kg body for 24 weeks at specific intervals (week 1, 2, 3, 4, 6, 8, 10, 12, 15, 18, 21 and 24). The total white blood cell (WBC) and neutrophil counts of treated rabbits were mostly slightly higher than control. Neutrophil count transiently significantly (p<0.05) decreased while lymphocyte count increased in week 6; monocyte (week4), basophil (week 4) and eosinophil (week 3) counts also briefly significantly (p<0.05) increased, suggesting an ephemeral negative immunological and allergic response of the rabbits to the administered extract. However, these events were not sustained as the values of these parameters subsequently returned to control levels. Red blood cell (RBC), packed cell volume (PCV) and haemoglobin (Hb) concentration of treated rabbits were slightly higher than control; the mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) were mostly statistically similar to control, implying improvement in haematopoiesis. This study revealed that long term administration of C. papaya extract had immunostimulatory and haematopoietic effects on normal rabbits

Keywords: Carica papaya, Immunostimulatory, Haematological, Rabbits, Medicinal plants