The Protective Role of Curcumin and Melatonin in Amelioration of Cadmium- Induced Cardiac Toxicity in Adult Albino Rats

Cadmium (Cd), a common toxic environmental and occupational pollutant which cause many organ toxicities probably due to its ability to induce oxidative stress. Curcumin and melatonin have many beneficial effects.
THE AIM of this study is to investigate the possible role of curcumin and melatonin in amelioration of cadmium-induced cardiac toxicity in rats.     
METHODS: This study was conducted on 140 adult male albino rats divided into 7 equal groups. Group I served as negative control. Group II received curcumin in an oral dose of 200mg/kg/day. Group III received melatonin in an oral dose of 10mg/kg/day .Group IV received cadmium chloride an oral dose of 5.2mg/kg/day for 15 days. By using the same doses and period Group V received cadmium chloride and curcumin, Group VI received cadmium chloride and melatonin, Group VII received cadmium chloride, curcumin and melatonin. At the end of the experiment, rats were sacrificed and samples were collected. Serum markers of myocardial damage were measured includingcreatine kinase –MB isoform (CK-MB) , lactate dehydrogenase (LDH) ,cardiac Troponin I (cTn-I). Oxidative status was evaluated by estimation of superoxide dismutase (SOD), catalase (CAT) and glutathione -S transferase (GST) activity Total antioxidant capacity (TAC) in serum in addition to tissue malondialdehyde (MDA) in heart.
RESULTS: Compared to negative control group, there was insignificant difference in the mean values of all the tested parameters in groups II and III, while significant difference was found in group IV. Group V showed significant difference from cadmium chloride group regarding all studied parameters but in comparison with control group, there was insignificant difference regarding cardiac parameters only. On the other hand, Group VI showed significant difference from Cd chloride group regarding all studied parameters and in comparison with control group, there was insignificant difference regarding cardiac parameters and SOD. As for Group VII, it showed significant difference from Cd chloride group, and insignificant difference from control group regarding all studied parameters.
CONCLUSION: Cadmium chloride caused significant oxidative cardiac toxicity. Co- administration of melatonin could improve such toxicity more significantly than curcumin did, while co-administration of both melatonin and curcumin provided superior protection against Cd chloride toxicities compared to either of them alone.
RECOMMENDATIONS: Further research is needed to investigate the beneficial effects of curcumin and melatonin and its applicability in humans vulnerable to Cd toxicity.