Figure 8. Confirmation of antioxidant effect of timolol on the contractile activity of diabetic rat heart via using different biochemical approaches.

The total oxidant status measured with respect to H₂O₂ and the total antioxidant status measured with respect to trolox (A) in both plasma and heart homogenate of control rats (CON group; white bar) and diabetic rats without treatment (DM group; black bar) or with TIM treatment (DM+TIM group; gray bar) for 4-week following the one week of diabetic status confirmation. (B) The total and free protein thiol levels measured in heart homogenate of the groups. Bars represent mean ± SEM. The number of rats is 12–17 for rats/group/protocol. Significant at ^*p<0.05 vs. CON group, ^†p<0.05 vs. DM group. (C) In vitro antioxidant activity and antioxidant status of TIM was measured with colorimetric methods. Antioxidant activity of increasing concentration of TIM is evaluated with absorbance changes in H₂O₂-induced signal. Bar graphs represent mean ± SEM values for 10-30-100-300 μM TIM applications on H₂O₂ included samples for expressing antioxidant activity. Bar graphs represent mean ± SEM values from Trolox or 10-30-100-300 μM TIM applications on ABTS chromogen solution for expressing antioxidant status (triple assays in each sample for each type of measurement). Significant at ^*p<0.05 vs. H₂O₂ or Trolox, and ^†p<0.05 vs. 10-μM TIM, ^#p vs. 30-μM TIM.