Toxicological Study of Leaf Extracts of Loranthus micranthus Linn Using Albino Wistar Rats

This study was aimed to investigate the effect of high sub-chronic doses of the aqueous and methanol leaf extracts of Loranthus micranthus on biochemical parameters of albino rats. Acute toxicity studies were performed according to standard methods. The animals were divided into 5 groups (n = 5). Aqueous and methanol extracts of L. micranthus leaves were administered in doses of 1000 and 2000 mg/kg body weight to four groups of rats respectively for 30 days through the intraperitoneal route. The fifth group served as control and received saline (5 ml/kg b.w, i.p). Blood samples were collected by retrorbital puncture and analyzed for biochemical and haematological parameters using assay kits. Acute toxicity studies indicated that both extracts had an LD50 > 5000 mg/kg. The results indicated significant (p<0.001) increases in alkaline phosphatase serum levels in both extract treated groups. The extracts also produced significant elevation in serum bilirubin levels when compared with normal control (p<0.05). Both extracts did not affect the levels of alanine and aspartate transaminases significantly (p>0.05). There were significant increase in the serum levels of urea in the extracts treated rats (p<0.05; p<0.01). The 2000 mg/kg aqueous extract produced significant increases in mean serum chloride and bicarbonate levels of treated rats when compared with control (p<0.01). The extracts produced significant decrease in the serum creatine kinase levels of treated rats in a non-dose related manner when compared with control (p<0.05). There were no significant changes in sodium and potassium levels of treated rats. The methanol extract had no significant effect on the haematological indices studied. The aqueous extract produced significant reductions in the haemoglobin and PCV of treated rats (p< 0.01). The total and differential leucocyte counts were not affected by extract treatment (p>0.05). From these results, the extracts caused significant biochemical changes but were not cytotoxic to leucocyte cell lines. Therefore, there should be caution in the long term use of these extracts.