Effect of Aqueous Extract of Psidium Guajava Leaves on Liver Enzymes, Histological Integrity and Hematological Indices in Rats

BACKGROUND: Serum alanine aminotransferase (ALT), aspartate aminotransferase(AST), alkaline phosphatase (ALP), albumin and total protein levels, as well as the tissue histological assay are known to be useful in assessing the functional integrity of the liver. Also, assessment of red and white blood cells count, hematocrit and hemoglobin concentrations is useful in determining the effect of some chemical substances on hemotopoietic system. In recent times, reports from medicinal plants research indicate that extracts from some plants are both hepatotoxic and hematotoxic, while others on the other hand are reported to be hepatoprotective and hematopoietic in action. This study considers the effects of aqueous extract of Psidium guajava (P. guajava) leaves on the histology and biochemical indices of liver function as well as hematological indices in rats. METHODS: In this study, phytochemical screening of the aqueous extract of P. guajava leaves was carried out. Also, male and female rats were administered with 200 mg/kg body weight oral daily doses of aqueous extract of P. guajava leaves for a period of 30 days. At the end of the administration period, the rats were anaesthesized with chloroform vapors and dissected for the collection of blood and liver tissues which were used for the hematopoietic and liver functions investigations. RESULTS: Preliminary phytochemical analysis of the plant leaves showed the presence of alkaloids, flavonoids, glycosides, polyphenols, reducing compounds, saponins and tannins. Liver function tests revealed that the serum ALT, AST and ALP, as well as the concentrations of total protein and albumin in male and female rats were not significantly (P > 0.05) affected by the oral administration of the extract. Histopathological study also did not show any adverse alteration in the morphological architecture of the liver tissues in both sexes of the animal model. However, red blood cell counts, hemotocrit and hemoglobin concentrations increased significantly (P < 0.05) on administration of the extract in both male and female rats. It was therefore observed that the effect of the extract on male rats was not significantly different (P > 0.05) from that obtained for the female rats. CONCLUSIONS: The results of this present study suggested that aqueous extract of Psidium guajava leaves may be hepatoprotective, and not hepatotoxic, with hematopoietic potentials in both male and female rats. These findings are therefore of clinical importance given the various reported medicinal potentials of the plant.