MAPK3 and renal fibrosis: In our present study, normalization of TGF-β1, p-Smad2/3, p-P38, p-ERK1/2 and p-JNK in Nimbidiol-treated diabetic mice suggested that Nimbidiol may mitigate renal fibrosis in type-1 DN by attenuating TGF-β1/Smad and MAPK signaling pathways.