CAT and diabetes mellitus: This decrease in CAT activity could result from inactivation by glycation of enzyme.23,24 Reduced activities of catalase in the red blood cells as well as tissues have been found during diabetes and this may result in a number of metabolic derangements due to the accumulation of free radicals such as superoxide radicals and hydrogen peroxides.25 Treatment with SMC and metformin reversed the activity and thereby minimizing the effect of stress induced damages but no statistical significant was found between HFD+SMC and HFD+metformin groups.