Impacts of trace metals on Roan Antelope, Hippotragus equines and its Endoparasite Strongyloides spp., sampled in the tropical rainforests of Odo Ona Kekere, Ibadan, Oyo State, Nigeria

Abstract

BackgroundRoan antelopes, together with other mammals, serve as man's proteins. Parasitic infections affect their growth and development and therefore reduce their yield. Samples of hunted roan antelopes (Hippotragus equines) were collected from Oluwo bushmeat Market, Epe, and Odo Ona Kekere in Oluyole Local Government Area of Ibadan, Nigeria. The intestine and liver of the roan antelopes were assessed based on endoparasites, accumulated trace metals, lipid profile, antioxidant biomarkers, and histopathology. The study was conducted to determine the impacts of trace metals on the enteric parasite Strongyloides spp. as an early warning to metal toxicity impacts on the antelopes and the consumers. ResultsThe study showed that the enteric parasites of the Roan antelope accumulated barium at a higher level than the host. The parasites showed great potentials for storage of cadmium and nickel, with the second-highest bioaccumulation factors in the study (>2), after zinc with bioaccumulation factor > 3. Vanadium's significant bioaccumulation factors are recorded only in the liver and intestine of the roan antelopes. The negative impact of the multi-stress conditions was evident in this study. For example, the significantly highest concentrations of zinc and barium in the parasites than the intestines and liver of the roan antelopes may partly be implicated in the outstandingly higher cholesterol, and low-lipid lipoproteins indicate dyslipidemia, which results from cellular damage due to stress. In stress conditions, some physiological reactions occur, including changes in hormones and components in the blood. These events might lead to higher cholesterol levels which may result in dyslipidemia. As seen in this study, although the levels of MDA in the investigated tissues were reasonably fairly stable, the upregulated SOD in the investigated tissues of the parasite served as an early warning signal of stress in the roan antelopes. ConclusionThe study revealed that Strongloides spp might be a reliable bioindicator of the metal burden in the roan antelopes. The enteric parasite may also serve as a good biosequestration tool to alleviate the toxic load of cadmium and nickel from the roan antelope. The synergistic impacts of cadmium and nickel on the parasites might reduce the infection intensity in the host. This study has demonstrated an empirical early warning against the deleterious accumulation of vanadium, barium, and zinc, which might rise beyond acceptable levels in the future, thus providing prognostic data for proactive decisions by stakeholders to make pragmatic plans and policy towards a sustainable conservation of the roan antelopes.