Aqueous extract of Terminalia avicennioides (Guillperr) ameliorates some pathological conditions in T. bruceibrucei-infected rats

Abstract

The study was designed to investigate the ability of the aqueous extract ofthe stem bark of Terminaliaavicennioides(ATA) to alleviate some pathological conditions in rats experimentally infected with Trypanosomabruceibrucei. The treatment groupsconsisted: Extract treated group [rats (n=9) were infected (10⁴ parasite per rat) intraperitoneally (i.p.) with the parasite and treated with 200 mg/kg b.w. of ATAfor six consecutive days; Negative control [rats (n=9) were not infected but administered 300 μL 100mM phosphate buffer saline pH 7.2, for six consecutive days]; Positive control group [rats (n=9) were infected with about 10⁴ T. bruceibrucei and left untreated but given 300 μL 100mM phosphate buffer saline pH 7.2, as placebo for six consecutive days]; Standard drug group [rats (n=9) were infected (104 parasite per rat) and given (i.p.) 3.5 mg/kg b.w. Diminazineaceturate] and the Extract control group [rats (n=9) in this group were not infected but were treated (i.m.) with 200 mg/kg b.w. of ATA for six consecutive days].Both extract and standard drug were administered intramuscularly (i.m.) and the mean values of the haematological and organ parameters in ATA/drug groups were compared with those of the control groups. Results revealed significant (p<0.05) suppression of parasitaemia by the extract. Comparative analysis of PCV, Red Cells and White Cells counts showed slight alleviation of anaemia and leucopenia. There was no variation seen with respect to the Mean ratios of kidneys and liver obtained from experimental rats relative to animals’ body weights when compared among all experimental groups.However, splenomegaly seen to accompany the infection were alleviated in the extract-treated group as well as the group of infected rats treated with the standard trypanocide. Distortion of parasite morphology was seen in Giemsa-stained thin film smear of blood obtained from extract treated rats as seen via oil immersion microscopy. The findings suggest that interactionwith parasite membrane could be an early step in the mechanism of action of ATA when used as component of herbal concoction in the traditional management of African Trypanosomiasis.

Keywords: Terminaliaavicennioides, Trypanosomabruceibrucei, Albino Rats, Anaemia, Leucopenia, Splenomegaly, Traditional medicine.