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

Background/Objectives: 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 Ocimum americanum properties using rat models. The aim of this study was to investigate the neuroprotective effects and potential modes of action of Ocimum americanum 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. Methods: Ocimum americanum 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. Results: 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. Conclusions: 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 Ocimum americanum as a nutraceutical or functional food in the aging process.