In Vitro Studies on the Effects of Aqueous Extracts of Syzygium Aromaticum Linn. (Cloves) and Zingiber Officinale Roscoe (Ginger) on Erythrocyte Osmotic Fragility in Sickle Cells

Abstract

Sickle cell disease is a genetically inherited blood disease that is characterized by the production of abnormal erythrocytes, shaped like a sickle. Definite cure for sickle cell disease is yet to be established, therefore, palliative methods such as antioxidant agents which reduce occurrence of intravascular haemolysis are employed. Naturally occurring antioxidants are found in Syzygium aromaticum Linn. (Clove) and Zingiber officinale (ginger) as documented by previous researches are therefore tested on the erythrocyte osmotic fragility of sickle cell red blood cells (RBC). Aqueous extracts of clove and ginger were obtained by maceration and antioxidant activity of the extracts was determined by 2, 2,-diphenyl-1-picryl-hydrazyl (DPPH) using ascorbate as standard. Blood samples from twenty five sickle cell disease subjects were collected and divided into five groups. Group one was control, groups two and three were incubated with 1mg/ml and 10mg/ml of clove extract respectively, while groups four and five were incubated with 1mg/ml and 10mg/ml of ginger extract respectively. Erythrocyte osmotic fragility was determined using graded series of hypotonic Sodium Chloride (NaCl) solutions of concentrations ranging from 0.1% to 0.9%. Analysis of Variance (ANOVA) and Turkey test was used to analyze data and test of significance was applied at p?0.05. The results revealed the presence of phenols, alkaloids, flavonoid and tannins in both clove and ginger extracts; glycosides were present in ginger but absent in clove. Antioxidant at low concentration of 50µg/ ml showed percentage inhibition of clove and ginger were 67.43% and 11.87%, respectively, and that of ascorbate was 20.15%. At high concentration of 250µg/ml, clove and ginger had percentage inhibition of 93.8% and 81.18% respectively, while ascorbate had 84.06%. Erythrocyte osmotic fragility test results showed complete haemolysis at 0.1% NaCl concentration in all groups. At 0.2% NaCl concentration, percentage haemolysis of the group treated with 10mg of clove 69.12 ± 0.05, was significantly lower (p?0.05) than the control (98.12 ± 0.05), while the group treated with 10mg ginger extract showed 98.02 ± 0.04 which is not significantly lower (p?0.05) than that of the control. At 0.5% NaCl concentration, percentage haemolysis of groups treated with 10mg clove extract and 10mg ginger extract were 8.400.18 and 20.42 ± 0.18, respectively, which were significantly lower (p?0.05) than that of the control group (45.90 ± 0.10). The groups treated with 1mg clove extract and 1mg ginger extract showed percentage haemolysis values of 38.04 ± 0.10 and 30.02 ± 0.10 respectively at 0.5% NaCl concentration which were significantly lower (p?0.05) than the control group (45.90 ± 0.10). Clove showed higher antioxidant activity than ginger. Both plants also demonstrated a capacity for maintaining erythrocyte membrane stability, with clove being better at lowering erythrocyte fragility than ginger.