Potential of Sorghum Polyphenols to Prevent and Treat Alzheimer’s Disease: A Review Article

Abstract

Alzheimer’s disease (AD) is characterized by the excessive deposition of extracellular amyloid-beta peptide (Aβ) and the build-up of intracellular neurofibrillary tangles containing hyperphosphorylated tau proteins. This leads to neuronal damage, cell death and consequently results in memory and learning impairments leading to dementia. Although the exact cause of AD is not yet clear, numerous studies indicate that oxidative stress, inflammation, and mitochondrial dysfunction significantly contribute to its onset and progression. There is no effective therapeutic approach to stop the progression of AD and its associated symptoms. Thus, early intervention, preferably, pre-clinically when the brain is not significantly affected, is a better option for effective treatment. Natural polyphenols (PP) target multiple AD-related pathways such as protecting the brain from Aβ and tau neurotoxicity, ameliorating oxidative damage and mitochondrial dysfunction. Among natural products, the cereal crop sorghum has some unique features. It is one of the major global grain crops but in the developed world, it is primarily used as feed for farm animals. A broad range of PP, including phenolic acids, flavonoids, and condensed tannins are present in sorghum grain including some classes such as proanthocyanidins that are rarely found in others plants. Pigmented varieties of sorghum have the highest polyphenolic content and antioxidant activity which potentially makes their consumption beneficial for human health through different pathways such as oxidative stress reduction and thus the prevention and treatment of neurodegenerative diseases. This review summarizes the potential of sorghum PP to beneficially affect the neuropathology of AD.

Role of Polyphenol-Derived Phenolic Acid in Mitigation of Inflammasome-Mediated Anxiety and Depression

“…There are a number of studies using a combination of polyphenol extracts, collected from natural sources, suggesting a therapeutic potential to alleviate or arrest sleep deprivation or stress-dependent cognitive deterioration [ 62 , 63 ]. In addition, the beneficial effect of polyphenolic components against AD-type cognitive decline, Aβ peptide accumulation in the brain, and tauopathies has been reported [ 64 , 65 , 66 , 67 ]. Accordingly, our data showed that MG improved CUS-induced anxiety and depression-related behavior, as indicated by more exposure to open spaces in the EPM and an increase in motility in the forced swim test, therefore promoting resilience in those animals subjected to chronic stress.…”

Prunus amygdalus var. amara (bitter almond) seed oil: fatty acid composition, physicochemical parameters, enzyme inhibitory activity, antioxidant and anti-inflammatory potential

“…Polyphenols are naturally occurring compounds and secondary metabolites of plants, generally produced to protect plants against biotic and abiotic stressors, acting as antioxidant, anti-inflammatory, antimicrobial, anti-diabetic, and anticancer molecules [43,44]. Total phenolic and flavonoids content of BAO were measured; the results are summarized in (Table 2).…”

Oxidative Stress in Tauopathies: From Cause to Therapy

“…Phenolic acids are wildly distributed in natural sources (fruits, coffee, tea, and grains), have long stability in foods and show a high intestinal intake [ 216 ] and efficient brain absorption [ 217 ]. These compounds have shown good effects in models of AD [ 218 ]; however, the effect in primary tauopathies has not been studied. Due to their diverse neuroprotective effects, which have been extensively reviewed elsewhere [ 218 , 219 ], phenolic acids are considered potential candidates to treat tauopathies.…”

“…These compounds have shown good effects in models of AD [ 218 ]; however, the effect in primary tauopathies has not been studied. Due to their diverse neuroprotective effects, which have been extensively reviewed elsewhere [ 218 , 219 ], phenolic acids are considered potential candidates to treat tauopathies.…”