Abstract

The present in vitro study investigated the levels of oxidative stress indicators, namely, malondialdehyde (MDA) and methaemoglobin (mHb) when sickle erythrocytes were incubated in aqueous leaf extracts of Anacardium occidentale, Psidium guajava and Terminalia catappa for 12 h. At regular time intervals of 3 h, portions of the incubation mixture were withdrawn and spectrophotometric method was used to assay for erythrocyte MDA concentrations and percent (%) mHb. The control analysis showed that erythrocyte MDA concentration increased from 2.45±0.35 to 3.13±0.59 mmol/ml (p > 0.05; p value = 0.801176). Erythrocyte MDA concentrations in the presence of the three extracts were higher than the control samples at t = 3 h (p > 0.05; p value = 0.963253). However, compared with the control sample at the given time (t), aqueous extract ofT. catappa, exhibited the highest capacity to cause reduction of erythrocyte MDA concentration [T. catappa] = 800 mg%; [MDA] = 2.89±0.33 mmol/ml; t = 12 h), representing 7.66% reduction of erythrocyte MDA concentration. Erythrocyte % mHb increased from 2.42±0.55 to 2.51±0.49% (p > 0.05; p value = 0.995171) in the control sample within the duration of 12 h. Incubation of sickle erythrocytes with aqueous extract of [P. guajava] = 800 mg% for 9 h caused reduction of Met.Hb% from 2.49±0.49% to 2.29±0.45%; p > 0.05; p value = 0.983519. Also, aqueous extract of T. catappaexhibited low capacity to cause reduction in erythrocyte %mHb. Aqueous extracts of A. occidentale,P. guajava and T. catappa exhibited variable capacities to hinder lipid peroxidation, but did not cause corresponding reduction in percent erythrocyte %mHb, as exemplified by negative correlation between the two oxidative stress indicators in the presence of T. catappa and higher concentrations of A. occidentale, P. guajava.

Key words: Malondialdehyde, methaemoglobin, erythrocyte, Anacardium occidentale, Psidium guajava, Terminalia catappa.