Oxidative effects of long-term onion (Allium cepa) feeding on goat erythrocytes

Abstract

Toxic compounds such as disulfides of onions cause oxidative-induced haemolysis in several animal species. In order to study the outcomes of long-term onion consumption on some oxidative haemolysis markers, 12 adult female goats were allocated to three groups, receiving 0% (served as control), 30% (dry matter basis) and 60% spring-grown onion for 60 days. Blood samples were obtained before feeding the onion and every 10 days up to 80 days for measuring malonyldialdehyde (MDA), methaemoglobin (MetHb), mean corpuscular fragility (MCF), serum-free haemoglobin and serum lactate dehydrogenase (LDH) and for evaluating their relation to packed cell volume (PCV) and haemoglobin (Hb) concentrations. PCV and Hb concentrations reduced, however, remained within reference ranges in onion-fed goats. MetHb showed a significant negative correlation with both PCV and Hb (P < 0.05) in onion-fed goats and a significant positive correlation with MCF and serum-free haemoglobin in goats receiving 30% onion. MetHb showed a significant positive correlation with MCF in goats fed with 60% onion. MDA showed a positive correlation with LDH and serum-free haemoglobin concentrations. These results suggest a role for oxidative damage in destructing red cells in goats feeding onions. However, it seems that up to 60% onions in diet can be consumed by goats without noticeable clinical anaemia.