Phytochemical screening and toxicological profile of methanolic extract of Picralima nitida fruit-rind (Apocynaceae)

Abstract

The methanol (M) extract of the fruit-rinds of Picralima nitida (PN) was analyzed phytochemically and evaluated for its toxicity effect in Wistar rats. The rats were administered graded doses (0.75, 1.5, 3, and 6 g kg−1 p.o) of the extract daily for 6 weeks and the toxicological effect of these varying levels of extract were examined on the serum, hepatic, and renal concentration of biochemical parameters as well as the histopathology of tissue section of these liver, kidney, and lungs. Clinical signs and hematology were also evaluated. Phytochemical analysis revealed that alkaloids and polyphenols were major compounds. Both biochemical and histopathological data presented demonstrate dose-dependent signs of toxicity. Our results show a significant elevation in serum concentration of aspartate amino-transferase, alanine amino-transferase, glucose, creatinine, total cholesterol, and protein with high-dose of PN treatment tested. PN also caused a significant reduction in hepatic malondialdehyde and a slight increase in glutathione concentration at the lowest dose tested. Renal urea level was reduced significantly in test groups. A significant change was observed in the relative weights of the spleen, heart, and kidneys. The total white blood cell count was reduced, whereas the hematocrit level was increased remarkably in animals that received high doses of the extract. The acute toxicity LD50 was estimated at 14.5 and 12.5 g kg−1 body weight for male and female, respectively. These results show that prolonged usage of this extract at 1.5–6 g kg−1 dose could cause liver, kidney, and lung injury, while the effect was mild at small dose levels (0.75 g kg−1). Thus, the extract should be taken with caution bearing in mind that higher doses could affect the liver, kidneys, and lungs.