Antiepileptic effects of long-term intracerebroventricular infusion of angiotensin-(1-7) in an animal model of temporal lobe epilepsy

Temporal lobe epilepsy (TLE) is the most frequent type of epilepsy and is often refractory to pharmacological treatment. In this scenario, extensive research has identified components of the renin-angiotensin system (RAS) as potential therapeutic targets. Therefore, the aim of the present study was to evaluate the effects of long-term treatment with angiotensin-(1-7) [Ang-(1-7)] in male Wistar rats with TLE induced by pilocarpine (PILO). Rats with TLE were submitted to intracerebroventricular (icv) infusion of Ang-(1-7) (200 ng/kg/h) for 28 days, starting at the first spontaneous motor seizure (SMS). Body weight, food intake, and SMS were evaluated daily. Behavioral tests and hippocampal protein levels were also evaluated at the end of the treatment. Ang-(1-7) treatment reduced the frequency of SMS and attenuated low anxiety levels, increased locomotion/exploration, and reduced body weight gain that was induced by TLE. Moreover, Ang-(1-7) positively regulated the hippocampal levels of antioxidant protein catalase and antiapoptotic protein B-cell lymphoma 2 (Bcl-2), as well as mammalian target of rapamycin (mTOR) phosphorylation, which were reduced by TLE. The hippocampal up-regulation of angiotensin type 1 receptor induced by TLE was also attenuated by Ang-(1-7), while the Mas receptor (MasR) was down-regulated compared with epilepsy. These data show that Ang-(1-7) presents an antiepileptic effect, increasing neuroprotection markers and reducing SMS frequency, body weight, and behavior impairments found in TLE. Therefore, Ang-(1-7) is a promising coadjutant therapeutic option for the treatment of TLE.