Low doses of folic acid can reduce hyperhomocysteinemia-induced glomerular injury in spontaneously hypertensive rats

Hypertension associated with hyperhomocysteinemia (HHcy) is associated with a high risk of vascular diseases. However, the mechanisms of HHcy-associated hypertensive renal damage and the efficacy of folic acid (FA) as a treatment have not been fully elucidated. The aim of the present study was to evaluate whether lowering the plasma homocysteine (Hcy) level using different doses of FA can reduce HHcy-associated glomerular injury in spontaneously hypertensive rats (SHRs) and to clarify the potential mechanisms of such effects. SHRs were randomized into a control group, HHcy group, HHcy + low-dose FA (LFA) group, and HHcy + high-dose FA (HFA) group. Compared with the control group, the HHcy group had reduced serum superoxide dismutase and GFR levels and elevated serum malondialdehyde and urinary albumin creatinine ratio levels. Increased extracellular matrix of the glomerulus and an increased glomerular sclerosis index, podocyte foot process effacement and fusion, as well as increased podocyte apoptosis, were observed in the HHcy group compared with the control group; these effects were associated with increased expression of NOX2 and NOX4 and decreased nephrin expression in renal tissue from SHRs with HHcy. HHcy-induced changes were counteracted by LFA and HFA treatment. Apart from lower levels of NOX2 in the HHcy + HFA group, there were no significant differences in other indicators between the HHcy + LFA and HHcy + HFA groups. These results suggest that even at a low dose, FA can reduce plasma Hcy and attenuate HHcy-induced glomerular injury by inhibiting oxidative stress and apoptosis.