**6. Discussion**

The elevated plus maze (EPM) and light and dark transition box (LDTB) tests were employed to measure anxiety. In order to assess anxiety, signs such as grooming frequency and duration, rearing, and stretch attend posture were also used [27].

Longer duration in the light box compartment shows decreased anxiety and greater length in the dark box compartment reveals increased anxiety [36].

The results of this experiment's light/dark transition box test revealed that the control group's dark chamber duration was shorter and its light chamber duration was longer than that of the experimental group. This suggests that the mice who were not exposed to CdCl2 experienced less anxiety.

However, there was a longer time in the dark room and a shorter time in the light chamber in the group exposed to CdCl2, indicating that exposure to CdCl2 enhanced anxiety. This is demonstrated in **Table 1** as a longer time of exposure had a more significant effect.

Also, the zinc and vitamin E treated groups that had previously been exposed to CdCl2 had a shorter time in the dark and a longer time in the light. This means that even after exposure to situations that had previously elevated anxiety, zinc and vitamin E may be able to reduce it.

Increased grooming frequency indicates higher levels of anxiety [39].

According to the experiment's findings, the CdCl2 exposed group groomed more frequently than the control group. Even more frequent grooming was observed in the group exposed for a longer period of time, indicating a proportionate rise in anxiety with CdCl2 exposure, compared to less frequent grooming in the zinc and vitamin E treated group. This supports **Table 2**'s finding that zinc and vitamin E lessen anxiety.

The animal spends more time in the enclosed arm when it is anxious, indicating that an increase in duration in the closed arm represents an increase in anxiety level and an increase in duration in the open arm suggests a drop in anxiety levels [31].

When compared to the control group, the CdCl2 group had a longer duration in the closed arm of the labyrinth and a shorter length in the open arm, according to the results of this experiment's elevated plus maze test. While the zinc and vitamin E treated group had a reduced duration in the closed arm and a higher duration in the open arm of the labyrinth, these effects are much more significant in the group *Ameliorative Effects of Zinc and Vitamin E on Physiological Changes after Exposure to Heavy… DOI: http://dx.doi.org/10.5772/intechopen.111518*

### **Figure 1.**

*Showing mechanisms of heavy metal toxicity.*

with longer period of exposure. Also, it revealed that the CdCl2 group groomed more frequently and for longer than the control group, whereas the zinc and vitamin E treated groups groomed less frequently and for shorter periods of time.

This supports the finding that anxiety is caused by cadmium chloride (CdCl2) exposure in mice, and that the longer the exposure, the more anxiety is caused. As shown in **Table 3** [20, 24], it also suggests that zinc and vitamin E, two important antioxidants, aid in reducing anxiety and stress.

The primary mechanisms of heavy metal toxicity include free radical production, which leads to oxidative stress, damage to biological molecules such as enzymes, proteins, lipids, and nucleic acids, as well as damage to DNA, which is crucial for both neurotoxicity and carcinogenesis. See **Figure 1**.
