Abstract
BACKGROUND: Cadmium is a ubiquitous heavy metal and a toxic pollutant in the biosphere which has been implicated as one of the factors responsible for cardiovascular risk and mortalities. This work was therefore conducted to ascertain the effects of omega-3 and/or quercetin on cadmium-induced cardio-toxicity in rats.
MATERIALS AND METHODS: Forty two (42) Wistar rats were assigned into 7 groups of 6 rats each and fed for 4 weeks with normal rat feed and drinking water. The treatment groups took either of cadmium chloride, omega-3 fatty acid and/or quercetin. The sham control groups 1 and 2 took olive oil (1mL/kg body wt. o.p) and DMSO (1mL/kg body wt. o.p) respectively. Serum was obtained from the blood samples for measurement of the various cardiac function indices. The heart was also harvested for histological studies. RESULTS: Results obtained showed that the cardiac function parameters in the sham control groups were not significantly different from normal control. The LD50 for cadmium was 3.90mg/kg bw. Serum troponin, myoglobin, creatinine kinase and C-reactive peptide increased significantly (p<0.05) in Cd group compared with controls, omega-3 and/or quercetin. Serum NO, NOS concentrations reduced while angiotensin-2 increased significantly (p<0.05) in Cd groups compared with control, omega-3 and/or quercetin groups. SOD, CAT, GPx reduced significantly (p<0.05) while MDA increased significantly in Cd groups compared with control, omega-3 and/or quercetin groups. Cytoarchitecture of cardiac tissues in Cd group showed severe structural damage to the cardiomyocytes, with displaced nuclei. These were ameliorated in omega-3 and/or quercetin treated groups.
CONCLUSION: In conclusion, administration of quercetin or omega-3 ameliorates the adverse effects of Cd on cardiac function parameters, this probably via its anti-oxidant, anti-inflammatory, and vasodilators enhancing effects. Quercetin or omega-3 had variable effects in ameliorating the adversity of Cadmium. However, combination of both quercetin and omega-3 produced a better ameliorating effect than when administered singly.

Key words: Cadmium, cardio-toxicity, Omega-3 fatty acid, quercetin, cardio-biomarkers