The improvement of oxidative stress by two proprietary herbal medicines in type 2 diabetes.

•It was a randomized, double-blind, placebo-controlled clinical trial about herbal medicines used in diabetic macrovascular disease.•The indexes including oxidative stress, atherosclerosis levels and macrovascular events were reliable and evidence-based.•It was concluded that the two herbal medicines are beneficial to oxidative stress in diabetic atherosclerosis.•The preventive and therapeutic values of herbal medicines will be proved in further diabetic complication researches.