PHYTOCHEMISTRY AND SUBCHRONIC TOXICITY EVALUATION OF ETHANOLIC STEM BARK EXTRACT OF RANDIA (XEROMPHIS) NILOTICA STAPF (RUBIACEAE) IN WISTAR RATS

Abstract

Aim: To evaluate the sub-chronic toxicity of the ethanolic stem-bark extract of Randia nilotica

in rats

Study Design: Observational/investigational studies

Place and Duration of Study: Department of Pharmacology and Therapeutics, Faculty of

Pharmaceutical Sciences, Ahmadu Bello University Zaria, Kaduna. April to December, 2013

Methodology: Phytochemicals were assayed. Acute oral lethal-dose (LD50) was estimated

following Lorke’s method. Four groups of 10 Wistar rats/group matched for weight and sex were

orally dosed for 28 days with normal saline, 250, 500 and 1000 mg/kg extract respectively. On

euthanizing, blood samples collected from each group into plain and anticoagulated (EDTA)

sample-bottles were used for biochemical and haematological analyses respectively. The brain,

heart, kidney, liver and spleen were isolated and each weighed and fixed in 10% buffered

formalin or Bouin’s fluid (brain only) for histopathology. The mean ± standard error of mean and

statistical significance at (P=.05) of obtained data were evaluated.

Results: All, except alkaloids, steroids, cardenolides and anthraquinones phytoconstituents were

present. No observable toxicity or mortality at 5000 mg/kg/bw following acute oral

administration. Significantly reduced PCV level occurred only at 1000 mg/kg. No significant

changes in Hb, RBC, MCHC, MCH, MCV, WBC differentials and ESR; as also in the levels of

BUN, creatinine or calcium; liver-enzymes, total-protein, albumin, total-cholesterol, triglycerides

and high-density-lipoproteins. Changes in organ-weights relative to control group were not

significant. Histologically, dose-dependent alterations occurred as neuronal degeneration and

congested blood vessels in the brain; myocardial congestion, haemorrhage and infiltration of

inflammatory cells; the kidney showed hyper-cellular atrophy of glomeruli, haemorrhage, tubular

necrosis, cellular infiltration, and Bowman’s capsule adhesion with parietal cell surface; the

spleen showed congestion of blood vessels and lymphocytes’ depletion, while the liver had

congestion of blood vessels, perivascular infiltration of inflammatory-cells and necrotic

hepatocytes.

Conclusion: This relatively short-term use changes in vital organs’ histology of this plant part

may be deleterious and thus, calls for caution.