Background: The aim of this study was to evaluate the effect of methanol extract of Mangifera indica on serum concentration of creatine kinase, total white blood cell (WBC) count and lymphocyte counts and the micro-anatomical architecture of the heart in chinchilla rabbits in order to find its safe and toxic levels. A total of 24 Chinchilla rabbits aged 10-14 weeks, divided into four experimental groups were orally administered the doses of none, 500, 1000 and 1500 mg/kg body weight of the methanol extract of M. indica, respectively, for 28 days.
Methods: The modified International Federation of Clinical Chemistry (IFCC) method was used to estimate the serum concentration of creatine kinase (CK (-MB)) while the haematology auto-analyser was used to estimate the total WBC count and lymphocyte count. The estimated values were subjected to analysis of variance using the SPSS software application (version 16) and expressed as mean±standard deviation. Tissue sections were stained by phosphotungstic acid haematoxylin and haematoxylin and eosin staining techniques.
Results: The result showed significant increases in serum concentrations of CK (-MB) (12.05±3.11-21.55±9.93 U/L) and total WBC count (5.33±0.66-6.51±0.38 103/μL) when the control group was compared with the treated groups (p<0.05). A significant dose-dependent decrease in the weight of the heart (0.053±0.00-0.041±0.003 kg) was also observed (p<0.05). An insignificant increase was observed in the lymphocyte count (4.47±0.94-5.18±0.76 103/μL) in the blood when compared with the control group (p>0.05). Significant differences were also observed in the body weight of the treated groups (p<0.05). The histopathological findings include atheroma, attenuated vasculature, lymphoplasmacytic infiltrates, necrotic and fibrotic vascular walls.
Conclusions: Thus, M. indica is indicated to have some health benefits at 500 mg/kg and shows toxicity on the micro-architecture of the heart at a concentration of ≥1000 mg/kg.