American Basil, Ocimum americanum, Has Neuroprotective Properties in the Aging Process

<b>Background/Objectives</b>: There is evidence concerning herbal medicines and plant-based compounds, including Lamiaceae species, as putative senolytic agents; however, there are only a few reports on <i>Ocimum americanum</i> properties using rat models. The aim of this study was to investigate the neuroprotective effects and potential modes of action of <i>Ocimum americanum</i> L. using ex vivo and in vivo assays to assess the effects of OAEE on hippocampal tissue from young adult and late middle-aged Wistar rats, with a focus on oxidative stress, cholinesterase activity, and neuroinflammatory markers. <b>Methods</b>: <i>Ocimum americanum</i> ethanol extract (OAEE) was incubated with hippocampal slices of young adult and late middle-aged male Wistar rats exposed to H₂O₂; an acute treatment with OAEE was evaluated in aversive memory performance and neurochemical parameters, such as hippocampal cellular oxidative state, and anticholinesterase activity, and a diet supplementation of OAEE were evaluated on several hippocampal biochemical parameters, such as oxidative state, anticholinesterase activity, and neuroinflammatory parameters in young adult and late middle-aged male rats. <b>Results</b>: OAEE reversed the H₂O₂-induced impaired cellular viability in hippocampal slices from young adult rats, as well as protected hippocampal slices against H₂O₂-induced damage in both young adult and late middle-aged Wistar rats, indicating its neuroprotective action. Chronic dietary OAEE supplementation reduced aging-induced increases in reactive species and lipid peroxidation levels in the hippocampus. Indeed, this supplementation reduced the TNF-α content in hippocampus from both ages, and IL-1β levels in young adult rats. <b>Conclusions</b>: The antioxidant actions of OAEE here observed, preventing the lipoperoxidation, as well as its anti-neuroinflammatory effect, might be related to neuroprotective effect. Our findings add evidence to support the idea of the potential use of <i>Ocimum americanum</i> as a nutraceutical or functional food in the aging process.