Geraniol Attenuates Oxidative Stress and Neuro-inflammation Mediated Cognitive Impairment in D‑galactose‑induced Mouse Aging Model

Abstract

D-galactose (D-gal) is a reducing sugar drug can induce artificial senescence and aging process that mimic natural aging along with the accompanying brain and liver injury in experimental animals. Therefore, chronic D-gal administration is widely used to induce cognitive impairment, Alzheimer disease and aging in rodents' models. Aging is a phenomenon in which oxidative stress and apoptosis play a vital role. Geraniol (GNL) belongs to the acyclic isoprenoid monoterpenes, presents in essential oils such as those from Cinnamomum tenuipilum and Valeriana officinalis. In the present study, we examined the effects of GNL on D-gal-induced oxidative stress and neuro-inflammation mediated memory loss in mice. Analyzing the behavioral differences between control and treated groups, including the elderly mice, revealed that GNL significantly improved memory in mice treated with D-gal-induced memory loss (supplementary videos are provided). The anti-inflammatory and the anti-oxidative role of GNL were confirmed by both histopathological investigations and biochemical analyses. Mechanistically, GNL appears to activate PI3K/Akt and thus upregulates the nuclear factor erythroid 2-related factor 2 (Nrf2) and the heme oxygenase 1 (HO-1) to reduce the oxidative stress and apoptosis induced after D-gal treatment leading to easing of neurological deficits and cognitive dysfunction in D-gal-induced aging mouse models. Accordingly, our comprehensive behavioral analysis and bioassays suggest GNL as a promising agent preventing cognitive impairment and neurological deficits associated with aging.

Anti-Inflammatory Activity of Geraniol Isolated from Lemon Grass on Ox-LDL-Stimulated Endothelial Cells by Upregulation of Heme Oxygenase-1 via PI3K/Akt and Nrf-2 Signaling Pathways

“…There are lots of essential oils extracted from lemongrass, rose, lavender and other aromatic plants. It exerts a range of pharmacological effects, including antibacterial, anti-inflammatory, antioxidant and neuroprotective [24][25][26][27][28][29]. As an antimicrobial agent, geraniol effectively prevented dysbiosis associated with colitis in mice.…”

“…Geraniol (GNL) is a monoterpene (Figure 1). Ther from lemongrass, rose, lavender and other aromatic pl logical effects, including antibacterial, anti-inflammat tive [24][25][26][27][28][29]. As an antimicrobial agent, geraniol effectiv with colitis in mice.…”