2.4.1. Assay of Catalase (CAT)

Catalase (CAT) activities in the supernatant of initially centrifuged samples of *Bellamya unicolor* were assayed as described by Chance and Maehly [29]. CAT activities were estimated spectrophotometrically at 230 nm. The enzyme extract prepared initially was used to measure the activity of catalase. Specific activity was expressed as Ug−<sup>1</sup> protein. 1 IU = change in absorbance/min/extinction coefficient (0.021).
