AR and liver dysplastic nodule: Eucommia lignans were able to attenuate the renal inflammatory response as well as improve the antioxidant capacity in DN rats by down-regulating IL-1β, TNF-α, and MDA, and up-regulating the activity of SOD; It is known that aldose reductase(AR)is a key mediator in DN as its up-regulation promotes the progression of DN and is considered a marker of DN (120).