Abstract

Various works have identified a number of herbal applications that have ameliorating effects on sickle cell disorders. The antisickling activities of dried Carica papaya leaves and roots of Fagara zanthoxyloides are being investigated in this study to determine the antioxidant properties of the plant extracts and their effects on homozygous sickle cell (SS) erythrocytes in vitro. The antisickling activity of both extracts were determined as well as analyses of hematological parameters, hemolysis of SS cells and formation of membrane associated denatured hemoglobin (MADH) used to measure the effects of plant extracts on the erythrocyte. Folin-Ctotal phenol and beta-carotene methods of assay were used to determine antioxidant activity, while the effect of plant extracts on oxidative stress was measured by assaying for superoxide dismutase, catalase, gluthathione transferase levels and lipid peroxidation. Results confirmed the potent antisickling activity of both plants. The levels of the oxidative stress enzymes (superoxide dismutase (SOD), catalase (CAT) and glutathione (GST) and lipid peroxidation were reduced after blood samples had been incubated with the extracts. The extracts therefore protected membrane integrity resulting in a reduction of red blood cells (RBC) hemolysis without met-hemoglobin formation. Both plant extracts possess potent antioxidant activity which may be responsible for their observed antisickling action.

Key words: Fagara, papaya, oxidative stress enzymes, antioxidant activity, hemolysis.

Abbreviation

SS, Sickle cell; MADH, membrane associated denatured hemoglobin; GST,glutathione; SOD, superoxide dismutase; CAT, catalase; RBC, red blood cells; Hb, hemoglobin;EDTA, ethylenediaminetetraacetic acid; FRIN, forestry research institute of Nigeria; HbAA,hemoglobin AA; HbSS, hemoglobin SS; PHBA, para-hydroxybenzoic acid; TBARS,thiobarbituric acid; MCHC, mean corpuscular hemoglobin concentration; RDW, red cell distribution width; MDA, malondiadehyde; SCD, sickle cell disease.