Abstract
Malaria parasite endemicity and development have been associated with ascorbic acid availability and the activity of G-6-PD. There is no record of studies that relate the two parameters in malaria subjects. Plasma ascorbic acid levels and glucose-6-phosphate dehydrogenase (G-6-PD) activity in symptomatic malaria, asymptomatic malaria and malaria negative subjects in Calabar Municipality were measured to evaluate the relationship. The level of ascorbic acid in malaria subjects (2.22±1.82m/dl) was significantly lower (P<0.05) than the level in control subjects (3.47±0.97mg/dl). However, the level of ascorbic acid in symptomatic malaria (2.22 ± 1.82 mg/dl) was significantly lower than the level in control subjects (P<0.05). The G-6-PD activities in malaria positive subjects, (asymptomatic, 12.75 ± 6.2U/gHb and symptomatic malaria, 18.5 ± 6.1U/gHb) were significantly higher than the activity in control subjects (8.34 ± 6.6U/gHb, P<0.05). The G-6-PD/ascorbic acid ratios in non-malaria (2.40), asymptomatic (3.73), and symptomatic (8.33) malaria subjects differed significantly (P<0.05). A positive correlations was observed between ascorbic acid level and G-6-PD activity in asymptomatic malaria subjects (r =0.444, p<0.05), while a negative correlation was observed in non-malaria subjects (r = 0.239, P<0.05). These results show an inverse relationship between ascorbic acid level and G-6-PD activity in malaria subjects. The G-6-PD/Ascorbic acid ratios
differentiate between non-malaria, asymptomatic and symptomatic malaria. Both the levels of ascorbic and the activity of G-6-PD vary significantly with malaria status and with level of malaria parasitaemia. From these finding we advice that G-6-PD activity results should be interpreted in
relation to malaria status in malaria endemic zones.
Key words: Malaria parasite, Ascorbic acid, G-6-PD, Symptomatic, Asymptomatic