Investigation of the healing effect of vitamin B12 againstPb and Zn toxicity in Carassius auratus (Gold fish)

As a result of contamination of aquatic environments with heavy metals, heavy metals accumulate in living organisms living in this environment. This accumulation shows a toxic effect on living organisms. In our study, the ameliorative effect of vitamin B12 against the toxicity caused by different concentrations of lead and zinc in Carassius auratus (Goldfish) was investigated. Fish were adapted to laboratory conditions for 15 days. After adaptation, 72 fish were grouped into 6 groups of 6 fish each, and the first 6 groups were labelled as the lead group and the remaining 6 groups as the zinc group. The first groups of two heavy metals were determined as the control group. For zinc groups, 1mg , 2mg, 3mg , 4mg , 5mg zinc was diluted in pure water and added to the aquariums. Similarly, for lead groups, 1mg, 2mg, 3mg, 4mg, and 5mg of lead were diluted in pure water and added to the aquariums. The fish were exposed to zinc and lead in these aquariums for 8 days. 3 fish from each group were taken and exposed to high dose anesthesia and their lives were terminated and removed to the freezer. The water of the remaining fish was changed and one ampoule of vitamin B12 was added to each aquarium and the fish were kept in this water for 7 days. The fish were exposed to high-dose anesthesia, and their lives were terminated. Liver tissues were taken from the fish in the first stage and heavy metal accumulations in the tissues were analyzed by ICP-MS method. The values measured in zinc group fish after heavy metal exposure were 109,361 mg/lt - 199,318 mg/lt - 273,084 mg/lt - 195,930 mg/lt - 251,540 mg/lt - 182,103 mg/lt, respectively. The values measured in zinc group fish after heavy metal exposure and additional vitamin B12 administration were 225,297 mg/lt - 130,948 mg/lt - 216,508 mg/lt - 151,280 mg/lt - 141,094 mg/lt - 283,180 mg/lt, respectively. The values measured after heavy metal exposure in lead group fish were 179,275 mg/lt - 148,066 mg/lt - 176,616 mg/lt - 174,278 mg/lt - 154,523 mg/lt - 349,929 mg/lt, respectively. In lead group fish, the values measured after supplemental vitamin B12 administration after heavy metal exposure were 68,586 mg/lt - 333,058 mg/lt - 258,900 mg/lt - 406,442 mg/lt - 325,594 mg/lt - 488,404 mg/lt, respectively. Considering the findings we obtained, if we make a separate evaluation for both heavy metals, B12 eliminates the toxicity caused by zinc. For lead, it shows that vitamin B12 is insufficient to prevent damage. B12 shows a healing effect only at low concentrations of lead. As a result, B12 can be used as a healing agent. However, the type, concentration, and extent of damage caused by heavy metals are taken into consideration. Keywords: Vitamin B12, Healing effect, Liver, Lead, Zinc