Effects Of Aqueous Leaf Extracts Of Loranthus Micranthus Linn. (Loranthaceae) On Biochemical And Haematological Profiles Of Albino Rats Infected With Trypanosoma Brucei Brucei

Abstract

The effects of oral administration of aqueous crude seed extracts of Loranthus micranthus on the biochemical and haematological parameters of albino rats infected with Trypanosoma brucei brucei were investigated for 28days. A total of seventy-two adult-male albino rats were divided into six groups: 3 treatment groups (400 mg/kg and 800 mg/kg and 1200mg/kg), infected and untreated control, one standard drug group and one normal control groups of twelve rats each. Each group was further replicated three times with four rats per replicate. The treatment groups were administered 400 mg/kg and 800 mg/kg and 1200mg/kg of aqueous leaf extracts of L. micranthus according to their body weights. Level of parasitaemia was ascertained in rats that were inoculated with T. brucei brucei at Day zero and subsequently every two days until the end of treatment. Blood samples were collected on weekly basis for various biochemical and haematological parameters using standard methods and assay kits. Two-way ANOVA was used to determine interactive effects of treatment and time while One-way ANOVA was used to test the effect of treatment. The phytochemical screening revealed high concentrations of tannins and flavonoids; moderate concentrations of alkaloids, saponins and steroids; and trace concentrations of glycosides and terpenes to be present in the aqueous crude extracts of L. micranthus leaves. The LD50 of the crude leaf extracts of L. micranthus showed no mortality at dose levels of 5000 mg/kg after twenty four hours. A significant decrease (P < 0.05) was observed in the mean values of body weights of the infected and treated animals throughout the duration of the experiment. Data from the study revealed that the level of parasitaemia in all the infected animals together with the infected and untreated control group was significantly high (P < 0.05) in comparison with those of the standard drug and normal control groups throughout the duration of the experiment. Liver marker enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) of the infected and treated rats as well as those of the infected and untreated control group showed marked significant increases (P < 0.05) in comparison with the standard drug and normal control groups. Similarly, data obtained show that serum levels of bilirubin, urea, creatinine and cholesterol were significantly high (P < 0.05) in the infected animals and in the infected and untreated control group. Serum albumin was significantly lower (P > 0.05) in the treatment groups with minimal increases in the group administered 800mg/kg of the aqueous leaf extract. The result obtained from the haematological analysis revealed that the haemoglobin (HB), packed cell volume (PCV), red blood cell (RBC) and its indices (mean cell haemoglobin, MCH, mean cell volume, MCV and mean cell haemoglobin, MCHC) of the infected rats significantly decreased (P < 0.05) at various dose levels of the aqueous leaf extract of L. micranthus when compared with the standard drug and normal control groups. The white blood cells (WBC) of the infected and treated rats and those of the infected and untreated control group showed significant increases (P < 0.05) in WBC counts when compared with the normal control group in all the weeks. WBC differentials revealed that neutrophils were significantly higher (P < 0.05) in the infected and treated animals in comparison to the standard drug control group in week 3, however lymphocytes, eosinophils, basophils were not significantly different (P > 0.05) from the standard drug control group in week 3 of extract administration. Furthermore, minimal increases in the WBC differentials were observed in the group administered 800mg/kg of the aqueous leaf extract of L. micranthus. Data generated in the present study showed that all infected and treated rats as well as the infected and untreated control group died from the resultant overwhelming parasitaemia unlike the case of those administered the standard drug. This is an indication that the extract lacks any anti-tryopanocidal activity. Thus, the aqueous leaf extract of Loranthus micranthus inhabiting the host plant Kola acuminata is an inadequate anti-trypanosomal agent.