Protective effects of curcumin towards anxiety and depression-like behaviors induced mercury chloride

The main objective of this work is to analyze the perinatal protective effects of curcumin (Cur) on the toxicity of inorganic mercury (mercuric chloride – HgCl(2)) in the developing mice offspring on their behavioral and biochemical changes. Six groups of pregnant mice (consisting of ten animals in each) were allocated in a way that Group I consuming tap water was used as control. Groups II to VI were the experimentally treated groups in which Group II and III received 150 and 300 ppm of curcumin, respectively; Group IV was given 10 ppm of HgCl(2); and Group V and VI were also exposed to 10 ppm of HgCl(2) but concurrently they were also treated with 150 and 300 ppm of curcumin, respectively. Appearance of vaginal plug was considered as the first day of pregnancy and all treatment started from day one of pregnancy until post-natal day 15 (PD 15) and the mothers were switched to plain tap water thereafter. At the age of PD 40, the male pups were subjected to measuring the depression in the light-dark chambers, forced swimming and tail suspension tests and to measuring their anxiety in plus-maze and open-field tests. Subsequently, after behavioral tests, the levels of corticosterone and cortisol hormones were estimated in the plasma of the experimental offspring. Behavioral tests were measured in the HgCl(2) treated offspring for the light-dark chambers; forced swimming test; tail suspension test; plus-maze test; and open –field test showed significant alterations in their depression, anxiety and locomotory activities. Biochemical estimation of corticosterone and cortisol hormones in the plasma of these offspring showed significant depletion in their levels. Treatment of these offspring with curcumin significantly and dose dependently ameliorated all the behavioral and biochemical disruptive effects in the offspring due to HgCl(2) toxicity. In conclusion, curcumin ameliorates the toxic effects of HgCl(2) in the offspring during gestation and lactation periods. Thus, exposure to HgCl(2) to mothers during pregnancy needs careful monitoring for minimizing its toxicity. Curcumin appears to be a promising ameliorating agent for such HgCl(2) toxicity; however, further studies are needed for establishing these preliminary findings.