HMOX1 and diabetic retinopathy: Relieving diabetic retinopathy progression, intensifying NRF2, HO-1, and NQO1 protein expressions, and CAT, SOD levels, while suppressing LDH, MDA, ROS levels and protein expressions of RAS, TFR1, and ACSL4, decreasing HbA1c, blood glucose levels and increasing body weight