Bioactive components from garlic on brain resiliency against neuroinflammation and neurodegeneration (Review)

Abstract

Garlic (Allium sativum) has been widely used for culinary and medicinal purposes. Aged garlic extract (AGE) and sulfur-containing compounds, including S-allylcysteine (SAC) are well documented botanical active components of garlic. AGE is prepared by the prolonged extraction of fresh garlic with aqueous ethanol and is considered a nutritional supplement with potential to promote human health. SAC is a water-soluble organosulfur compound and the most abundant component of AGE. Studies have demonstrated that both AGE and SAC can exert neuroprotective effects against neuroinflammation and neurodegeneration. Another bioactive component in AGE is N-α-(1-deoxy-D-fructos-1-yl)-L-a rginine (FruArg) although less is known about the metabolic activity of this compound. The main aim of this review was to provide an undated overview of the neuroprotective perspectives of these active garlic components (AGE, SAC and FruArg). Of interest, our studies and those of others indicate that both AGE and FruArg are involved in the regulation of gene transcription and protein expression. AGE has been shown to reverse 67% of the transcriptome alteration induced by endotoxins-lipopolysaccharide (LPS), and FruArg has been shown to account for the protective effects by reversing 55% of genes altered in a cell-based neuroinflammation paradigm stimulated by LPS in murine BV-2 microglial cells. AGE and FruArg can alleviate neuroinflammatory responses through a variety of signaling pathways, such as Toll-like receptor and interleukin (IL)-6 signaling, as well as by upregulating the nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated oxidative stress pathways known to promote microglial resiliency against neuroinflammation and neurodegeneration. The capability of FruArg to pass through the blood-brain barrier further supports its potential as a therapeutic compound. In summary, these experimental results provide new insight into the understanding of the neuroprotective effects of garlic components in promoting brain resiliency for health benefits.

Whole-plant foods and their macromolecules: untapped approaches to modulate neuroinflammation in Alzheimer’s disease

“…Administration of GO (46 mg/ kg body weight) markedly attenuated impaired short-term memory and motor coordination after global cerebral ischemia for 10 min followed by reperfusion for 24 h in mice (Gupta, Singh, and Sharma 2003). A recent study reported that the neuroprotective effect of garlic could be attributed to organosulfur components (Song et al 2020). SAC down-regulated hippocampal nuclear NF-κB and attenuated oxidative stress, resulting in mitigating cognitive deficits (Zarezadeh et al 2017).…”

Chemical and biological studies on Allium sativum L. (1952-2020): A comprehensive review

“…AGE and FruArg can reduce neuroinflammatory reactions via a variety of signaling pathways, including Toll-like receptor and interleukin (IL-6) signaling, as well as upregulation of the nuclear factor erythroid 2-related calculate 2 (Nrf2)-mediated oxidative stretch pathways, which have been shown to improve microglial resistance to neuroinflammation and neurodegeneration. FruArg's capacity to cross the blood-brain barrier (BBB) suggests that it could be used as a medicinal drug [78]. DADS and DATS were found to have neuroprotective properties.…”

Functional Foods: An Approach to Modulate Molecular Mechanisms of Alzheimer’s Disease

“…It is known that onion, garlic, grapes, rosemary, broccoli, spinach, turmeric, parsley, etc., possess considerable antioxidant activities [38,40] and prevent several neurodegenerative diseases including AD [41]. For example, the odorless aged garlic extract (AGE) contains antioxidant chemicals that prevent oxidative damage [42]. AGE has been shown to protect against cellular damage that occurs due to the accumulation of β-amyloid peptide (Aβ) in vitro and to counteract the toxicity of Aβ [42].…”

“…For example, the odorless aged garlic extract (AGE) contains antioxidant chemicals that prevent oxidative damage [42]. AGE has been shown to protect against cellular damage that occurs due to the accumulation of β-amyloid peptide (Aβ) in vitro and to counteract the toxicity of Aβ [42]. Furthermore, always in relation to AD pathogenesis, AGE can reduce the hyperphosphorylation of tau protein by modulating the activity of glycogen synthase kinase-3β (GSK) [42].…”

“…AGE has been shown to protect against cellular damage that occurs due to the accumulation of β-amyloid peptide (Aβ) in vitro and to counteract the toxicity of Aβ [42]. Furthermore, always in relation to AD pathogenesis, AGE can reduce the hyperphosphorylation of tau protein by modulating the activity of glycogen synthase kinase-3β (GSK) [42]. The neuroprotective effects of AGE on AD-related cognitive dysfunction have also been explored taking advantage of the ability of the active components of garlic to pass through the blood-brain barrier (BBB), a property which further supports its potential as a therapeutic compound.…”