Histopathologic effect of lead and cadmium and the mitigating effect of standard metal chelator and spice mixture

Abstract

Lead and cadmium are toxic to the liver and kidney. Standard metal chelators have deleterious effects on the body. Hence, natural spices like ginger and garlic have been studied as alternative mitigants. This study uniquely evaluates the possible synergistic mitigating effect of the mixture of both spices (SM) in comparison with that of calcium sodium ethylenediaminetetraacetic acid (CaNaEDTA), a standard metal chelator (MC). A total of 10 groups of 6 rats each were used and they were fed with finisher mash and water ad libitum. Group 1 was given only feed and water, Additionally, Group 2 was given 50 mg/kg lead chloride (PbCl₂₎, group 3 was given 15 mg/kg cadmium chloride (CdCl), while group 4 received 15 mg/kg CdCl₂ plus 50 mg/kg PbCl₂. Group 5, 6 and 7 received the same treatment as group 2,3 and 4 plus 15 mg/kg CaNaEDTA; while Group 8, 9 and 10 received the same treatment as group 2,3 and 4 respectively, plus 300 mg/kg of SM. Treatments were given at 72-hour intervals for 6 weeks through oral gavage. The rats were sacrificed, and their harvested organs were analyzed histologically. Lead and cadmium induced severe inflammatory changes, necrosis, fatty degeneration, and pyknosis in the liver and kidney. Co-administration of the metals and MC resulted in moderate fatty changes, moderate degeneration, and mild inflammation in both organs. Likewise, co-administration of the metal with SM produced moderate degeneration and moderate fatty changes with mild inflammation in the kidney. The study shows that the ameliorating effect of the SM on lead and cadmium-induced renal toxicity is comparable to that of the MC. However, SM did not produce any appreciable ameliorative effect in the liver. Therefore, these readily available spices can be used for prophylactic and therapeutic purposes against heavy metal-induced renal toxicity.