ORIGINAL ARTICLE Effects of aqueous leaf extracts of Loranthus micranthus Linn. on hematological profile of albino rats infected with Trypanosoma brucei brucei Jude Victor Egbuji 1 & Vincent Chikwendu Ejere 1 & Godwin Chigozie Ugwu 1 & Chinagorom Laureta Okanya 1 Received: 14 January 2019 /Accepted: 6 May 2019 # Springer-Verlag London Ltd., part of Springer Nature 2019 Abstracts African trypanosomiasis has continued to threaten human health and economical development (Kuzoe Acta Trop 54:153–162, 1993; WHO J Tsetse Tryp Info Quart 3:4–9, 2000). It is caused by parasitic protozoa of the genus Trypanosoma (Adeiza et al. J Med Plant Res 4(17):1770–1777, 2010), and the distribution corresponds with that of tsetse flies. Effects of aqueous leaf extracts of Loranthus micranthus on hematological parameters of albino rats infected with Trypanosoma brucei brucei were investigated for 28 days using standard methods. The HB, PCV, RBC, and its indices (MCH, MCV, and MCHC) of the infected rats significantly decreased (P < 0.05) at various dose levels of the extracts when compared with the control groups. The WBC counts of the treatment groups and those of the negative control group showed significant increases (P < 0.05) in all the weeks when compared with the normal control. The WBC differentials revealed that neutrophils were significantly higher (P < 0.05) in the test group in comparison with the positive control group at week 3; however, lymphocytes, eosinophils, and basophils were not significantly different (P > 0.05) from the positive control in week 3. Furthermore, minimal increases in the WBC differentials were observed in the group administered 800 mg/kg of the plant extract. The present study showed that all test rats and the negative control group died from the resultant overwhelming parasitemia at week 4 unlike the case of those administered the standard drug, which is an indication that the extract lacks anti-trypanocidal activity. Thus, the aqueous leaf extract of Loranthus micranthus is an inadequate anti-trypanosomal agent. Keywords Parasitaemia . Trypanosomiasis . Hematological profile . Albino rats . Aqueous leaf extracts . Loranthus micranthus Introduction African trypanosomiasis has been a threat to human health and economical development (Kuzoe 1993; WHO 2000). Trypanosomiasis is a lethal disease which affects both man and animals, and it is caused by a parasitic protozoa of the genus Trypanosoma (Adeiza et al. 2010). The distribution of trypanosomiasis corresponds roughly with that of tsetse flies. Trypanosomiasis, which is also known as sleeping sickness, is caused by Trypanosoma brucei gambiense and or Trypanosoma brucei rhodesiense following an infective bite from tsetse fly (Welburn et al. 2001; Haydon et al. 2002; WHO 2006). However, up to 80% of the Nigerian land mass is infested by the vector of the parasite, tsetse fly. Presently, the disease in cattle has been on the increase due to the menace of the vector, drug resistance and presence of other hematoph- agous flies (Holmes 2000). Transmission of this parasite is mostly through the bite of an infected tsetse fly; other ways include mother to child transmission through the placenta, mechanical transmission through other blood sucking insects (though it is difficult to assess the epidemiological impact of this mode of transmission), accidental transmissions/infection due to pricks from contaminated needles in the laboratory (Seed 1998; WHO 2006; Kennedy 2006). Pathogenic trypanosome infections of domestic animals in sub-Saharan African largely account for the low livestock pro- ductivity in the continent thus, making it an important priority for the agricultural and biomedical and public agencies (Aliyu et al. 2010). The parasites infestation constitutes the greatest * Godwin Chigozie Ugwu godwin.ugwu@unn.edu.ng 1 Department of Zoology and Environmental Biology, University of Nigeria, Nsukka, Enugu State, Nigeria Comparative Clinical Pathology https://doi.org/10.1007/s00580-019-02973-4