Clinically, patients with
diabetes mellitus (DM) are more susceptible to ischemic renal injury (IRI) than non-diabetic (ND) patients. Besides, IRI predisposes distant organ dysfunctions including, neurological dysfunction, in which the major contributor remains renin-angiotensin system (RAS). Interestingly, the role of depressor arm of RAS on IRI-associated neurological sequalae remains unclear. Hence, this study aimed to delineate the role of
angiotensin II type 2 receptor (AT2R) and
angiotensin-converting enzyme 2 (ACE2) under the same. ND and
Streptozotocin-induced DM rats with bilateral IRI were treated with AT2R agonist-
Compound 21 (
C21) (0.3 mg/kg/day, i.p.) or ACE2 activator-
Diminazene Aceturate (Dize), (5 mg/kg/day, p.o.) either alone or as combination
therapy. Effect of IRI on neurological functions were assessed by behavioural, biochemical, and histopathological analysis. Immunohistochemistry, ELISA and qRT-PCR experiments were conducted for evaluation of the molecular mechanisms. We found that in ND and DM rats, IRI causes increased hippocampal MDA and
nitrite levels, augmented inflammatory
cytokines (
granulocyte-colony stimulating factor,
glial fibrillary acidic protein), altered
protein levels of Ang II, Ang-(1-7) and
mRNA expressions of At1r, At2r and Masr. Treatment with
C21 and Dize effectively normalised above-mentioned pathological alterations. Moreover, the protective effect of
C21 and Dize combination
therapy was better than respective monotherapies, and more likely, exerted via augmentation of
protein and
mRNA levels of depressor arm components. Thus, AT2R agonist and ACE2 activator
therapy prevents the development of IRI-associated neurological dysfunction by attenuating oxidative stress and
inflammation, upregulating depressor arm of RAS in brain under ND and DM conditions.