Tempeh attenuates cognitive deficit, antioxidant imbalance, and amyloid β of senescence-accelerated mice by modulating Nrf2 expression via MAPK pathway

Exploring the Geroprotective Potential of Nutraceuticals

Aging is the result of the accumulation of a wide variety of molecular and cellular damages over time, meaning that "the more damage we accumulate, the higher the possibility to develop age-related diseases". Therefore, to reduce the incidence of such diseases and improve human health, it becomes important to find ways to combat such damage. In this sense, geroprotectors have been suggested as molecules that could slow down or prevent age-related diseases. On the other hand, nutraceuticals are another set of compounds that align with the need to prevent diseases and promote health since they are biologically active molecules (occurring naturally in food) that, apart from having a nutritional role, have preventive properties, such as antioxidant, anti-inflammatory and antitumoral, just to mention a few. Therefore, in the present review using the specialized databases Scopus and PubMed we collected information from articles published from 2010 to 2023 in order to describe the role of nutraceuticals during the aging process and, given their role in targeting the hallmarks of aging, we suggest that they are potential geroprotectors that could be consumed as part of our regular diet or administered additionally as nutritional supplements.

Fermented soybean foods (natto) ameliorate age-related cognitive decline by hippocampal TAAR1-mediated activation of the CaMKII/CREB/BDNF signaling pathway in senescence-accelerated mouse prone 8 (SAMP8)

Natto is a traditional fermented soybean-based food that has been an integral part of Japanese cuisine for several centuries. Although there have been extensive studies on the cognitive benefits of soybeans, only limited studies have examined the effects of natto on cognitive function. This study investigated the potential cognitive benefits of natto in senescence-accelerated mouse-prone 8 (SAMP8) mice. After 12 weeks of oral administering natto fermented for 18 h, the spatial learning and memory performance were improved compared with those in SAMP8 control mice. Furthermore, activation of the brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB)/cAMP response element-binding protein (CREB) signaling and N-methyl-D-aspartate receptor (NMDAR)-calcium/calmodulin-dependent protein kinase II (CaMKII) cascade was observed in the hippocampus of SAMP8 mice that were fed natto. Additionally, natto administration upregulated trace amine-associated receptor 1 (TAAR1) as a modulator of NMDAR. These findings suggest that natto ameliorates cognitive decline by activating the TAAR1-mediated CaMKII/CREB/BDNF signaling pathway in the hippocampus of SAMP8 mice.

Effect of Nrf2 loss on senescence and cognition of tau-based P301S mice

Cellular senescence may contribute to chronic inflammation involved in the progression of age-related diseases such as Alzheimer's disease (AD), and its removal prevents cognitive impairment in a model of tauopathy. Nrf2, the major transcription factor for damage response pathways and regulators of inflammation, declines with age. Our previous work showed that silencing Nrf2 gives rise to premature senescence in cells and mice. Others have shown that Nrf2 ablation can exacerbate cognitive phenotypes of some AD models. In this study, we aimed to understand the relationship between Nrf2 elimination, senescence, and cognitive impairment in AD, by generating a mouse model expressing a mutant human tau transgene in an Nrf2 knockout (Nrf2KO) background. We assessed senescent cell burden and cognitive decline of P301S mice in the presence and absence of Nrf2. Lastly, we administered 4.5-month-long treatments with two senotherapeutic drugs to analyze their potential to prevent senescent cell burden and cognitive decline: the senolytic drugs dasatinib and quercetin (DQ) and the senomorphic drug rapamycin. Nrf2 loss accelerated the onset of hind-limb paralysis in P301S mice. At 8.5 months of age, P301S mice did not exhibit memory deficits, while P301S mice without Nrf2 were significantly impaired. However, markers of senescence were not elevated by Nrf2 ablation in any of tissues that we examined. Neither drug treatment improved cognitive performance, nor did it reduce expression of senescence markers in brains of P301S mice. Contrarily, rapamycin treatment at the doses used delayed spatial learning and led to a modest decrease in spatial memory. Taken together, our data suggests that the emergence of senescence may be causally associated with onset of cognitive decline in the P301S model, indicate that Nrf2 protects brain function in a model of AD through mechanisms that may include, but do not require the inhibition of senescence, and suggest possible limitations for DQ and rapamycin as therapies for AD.

Effects of Phytochemicals from Fermented Food Sources in Alzheimer's Disease In Vivo Experimental Models: A Systematic Review

The socioeconomic burden of Alzheimer's Disease (AD) stems from its characteristic multifactorial etiology and, implicitly, the difficulties associated with its treatment. With the increase in life expectancy and health awareness, nutraceuticals and functional foods are filling in the gaps left by the limitation of classical medical treatment in chronic conditions associated with lifestyle factors, such as neurological disorders. Processes, such as fermentation that enhance food phytochemical content are garnering increased attention due to their functional and health-related properties. This systematic review aims to provide an overview of the evidence of phytochemicals from fermented food sources inducing therapeutic outcomes and cognitive benefits from in vivo experimental models of Alzheimer's Disease. The present systematic review was conducted in accordance with PRISMA guidelines. Searches were performed in the following databases: MEDLINE, Embase, Cochrane, Scopus, Google Scholar, and Science Citation Index Expanded (Web of Science) by two independent reviewers. Titles and abstracts yielded by the search were screened for eligibility against the inclusion criteria. The search strategy yielded 1899 titles, encompassing studies from 1948 to 2022. After the removal of duplicates, and screening of titles, abstracts, and full texts, thirty three studies obtained from the original search strategy and seven studies from references satisfied the inclusion criteria and were included in the present systematic review. Several studies have emphasized the potential of fermentation to yield small-molecule phytochemicals that are not present in raw products. When these phytochemicals are combined, their collective strength has demonstrated the ability to exceed the antioxidant, anti-inflammatory, and neuroprotective benefits of individual phytochemicals when given in their pure form. Among the various fermented foods that have been studied, soy isoflavones obtained through fermentation have shown the most substantial evidence of altering phytochemical content and improving outcomes in animal models of AD. While promising in initial results, other fermented foods and traditional medicines require more detailed research in order to establish their effectiveness and proper utilization. As is, many of the experimental designs lacked phytochemical analysis of the used fermented product or comparison with the non-fermented counterpart. This, coupled with proper reporting in animal studies, will significantly raise the quality of performed studies as well as the weight of obtained results.

Fermented Soy Products and Their Potential Health Benefits: A Review

In the growing search for therapeutic strategies, there is an interest in foods containing natural antioxidants and other bioactive compounds capable of preventing or reversing pathogenic processes associated with metabolic disease. Fermentation has been used as a potent way of improving the properties of soybean and their components. Microbial metabolism is responsible for producing the β-glucosidase enzyme that converts glycosidic isoflavones into aglycones with higher biological activity in fermented soy products, in addition to several end-metabolites associated with human health development, including peptides, phenolic acids, fatty acids, vitamins, flavonoids, minerals, and organic acids. Thus, several products have emerged from soybean fermentation by fungi, bacteria, or a combination of both. This review covers the key biological characteristics of soy and fermented soy products, including natto, miso, tofu, douchi, sufu, cheonggukjang, doenjang, kanjang, meju, tempeh, thua-nao, kinema, hawaijar, and tungrymbai. The inclusion of these foods in the diet has been associated with the reduction of chronic diseases, with potential anticancer, anti-obesity, antidiabetic, anticholesterol, anti-inflammatory, and neuroprotective effects. These biological activities and the recently studied potential of fermented soybean molecules against SARS-CoV-2 are discussed. Finally, a patent landscape is presented to provide the state-of-the-art of the transfer of knowledge from the scientific sphere to the industrial application.

Fermented soybean foods: A review of their functional components, mechanism of action and factors influencing their health benefits

After thousands of years of evolution and development, traditional fermented soybean foods, with their unique charm, have gained a stable place in the global market. With the explosive development of modern biological technologies, some traditional fermented soybean foods that possess health-promoting benefits are gradually appearing. Physiologically active substances in fermented soybean foods have received extensive attention in recent decades. This review addresses the potential health benefits of several representative fermented soybean foods, as well as the action mechanism and influencing factors of their functional components. Phenolic compounds, low-molecular-weight peptides, melanoidins, furanones and 3-hydroxyanthranilic acid are the antioxidative components predominantly found in fermented soybean foods. Angiotensin I-converting enzyme inhibitory peptides and γ-aminobutyric acid isolated from fermented soy foods provide potential selectivity for hypertension therapy. The potential anti-inflammatory bioactive components in fermented soybean foods include γ-linolenic acid, butyric acid, soy sauce polysaccharides, 2S albumin and isoflavone glycones. Deoxynojirimycin, genistein, and betaine possess high activity against α-glucosidase. Additionally, fermented soybean foods contain neuroprotective constituents, including indole alkaloids, nattokinase, arbutin, and isoflavone vitamin B12. The anticancer activities of fermented soybean foods are associated with surfactin, isolavone, furanones, trypsin inhibitors, and 3-hydroxyanthranilic acid. Nattokinase is highly correlated with antioxidant activity. And a high level of menaquinones-7 is linked to protection against neurodegenerative diseases. Sufficiently recognizing and exploiting the health benefits and functional components of traditional fermented soybean foods could provide a new strategy in the development of the food fermentation industry.

Clinical and Preclinical Studies of Fermented Foods and Their Effects on Alzheimer’s Disease

The focus on managing Alzheimer’s disease (AD) is shifting towards prevention through lifestyle modification instead of treatments since the currently available treatment options are only capable of providing symptomatic relief marginally and result in various side effects. Numerous studies have reported that the intake of fermented foods resulted in the successful management of AD. Food fermentation is a biochemical process where the microorganisms metabolize the constituents of raw food materials, giving vastly different organoleptic properties and additional nutritional value, and improved biosafety effects in the final products. The consumption of fermented foods is associated with a wide array of nutraceutical benefits, including anti-oxidative, anti-inflammatory, neuroprotective, anti-apoptotic, anti-cancer, anti-fungal, anti-bacterial, immunomodulatory, and hypocholesterolemic properties. Due to their promising health benefits, fermented food products have a great prospect for commercialization in the food industry. This paper reviews the memory and cognitive enhancement and neuroprotective potential of fermented food products on AD, the recently commercialized fermented food products in the health and food industries, and their limitations. The literature reviewed here demonstrates a growing demand for fermented food products as alternative therapeutic options for the prevention and management of AD.

PAYCS Alleviates Scopolamine-Induced Memory Deficits in Mice by Reducing Oxidative and Inflammatory Stress and Modulation of Gut Microbiota-Fecal Metabolites-Brain Neurotransmitter Axis

The bioactive peptide PAYCS (Pro-Ala-Tyr-Cys-Ser) identified from anchovy hydrolysates has been reported to be positive in memory alleviation. The gut microbiota-brain axis plays a vital role in brain functions, which could be affected by nutritional supplementation. Herein, we found that PAYCS at different concentrations (PAYCS-L and PAYCS-H) showed various improving effects in behavioral tests and alleviation effects on oxidative as well as inflammatory stress in the scopolamine-induced AD mouse model. The 16S rRNA results illustrated that PAYCS-L altered the ratio of Bacteroidetes/Firmicutes and PAYCS treatment elevated the relative abundance of Cacteroidaceae and Prevotellaceae. Notably, administration of PAYCS significantly upregulated memory-related metabolites and neurotransmitters. Overall, PAYCS-L reversed memory deficits of amnesiac mice partially via the modulation of gut microbiota-metabolites-brain neurotransmitter axis. For PAYCS-H, functions might be involved in the reversal of oxidative and inflammatory impairments in the liver and serum, which was also associated with the changed intestinal microbiota and fecal metabolites.

Tempeh Consumption and Cognitive Improvement in Mild Cognitive Impairment

INTRODUCTION

Tempeh consumption has been linked to the improvement of cognitive function in older people. However, to what extent the amount of microorganism or the size of tempeh serving consumed per day influences the benefit to cognitive functions has not yet been studied.

METHODS

This experimental study involved a total of 90 respondents, who were divided into 3 groups: group A (consuming 100 g of Tempeh A/day), group B (consuming 100 g of Tempeh B/day), and group C (control). Intervention was given for 6 months. Cognitive assessments were done before and after the intervention. Blood uric acid level was checked at the end of intervention to examine the effect of tempeh consumption on this. The inclusion criteria were respondents aged 60 years or over with mild cognitive impairment (MCI) who agreed not to consume other fermented food during the study period. Respondents with diabetes were excluded.

RESULTS

There were 84 subjects at the end of the study, majority being female (71.4%) and aged over 65 years (72.6%). An increase in global cognitive scores was found in both groups A and B. The increase in language domain scores was found only in group A.

CONCLUSION

Both Tempeh A or Tempeh B consumption for 6 months appeared to be beneficial in improving global cognitive function of older people with MCI. Consuming Tempeh A, which had a lower number of microorganisms, was also associated with an improvement in the language domain.

Traditional fermented foods with anti-aging effect: A concentric review

Fermentation has been applied since antiquity as a way to preserve foodstuff or as a necessary step in the production of a variety of products. The research was initially focused on accurate description of production procedure and identification of parameters that may affect the composition and dynamics of the developing micro-communities, since the major aim was standardization and commercial exploitation of the products. Soon it was realized that consumption of these products was associated with an array of health benefits, such as anti-hypertensive, anti-inflammatory, anti-diabetic, anti-carcinogenic and anti-allergenic activities. These were credited to the microorganisms present in the fermented products as well as their metabolic activities and the bio-transformations that took place during the fermentation process. Aging has been defined as a gradual decline in the physiological function and concomitantly homeostasis, which is experienced by all living beings over time, leading inevitably to age-associated injuries, diseases, and finally death. Research has focused on effective strategies to delay this process and thus increase both lifespan and well-being. Fermented food products seem to be a promising alternative due to the immunomodulatory effect of microorganisms and elevated amounts of bioactive compounds. Indeed, a series of anti-aging related benefits have been reported, some of which have been attributed to specific compounds such as genistein and daidzein in soybeans, while others are yet to be discovered. The present article aims to collect and critically discuss all available literature regarding the anti-aging properties of fermented food products.

Chemoprevention of elite tea variety CFT-1 rich in EGCG against chemically induced liver cancer in rats

Camellia sinensis (L.) O. Kuntze cv. CFT-1 is an elite tea variety bred by sexual hybridization with a high content of epigallocatechin-3-gallate (EGCG) as 134.2 mg/g (which is 2.54-fold that of the common variety). This study was to evaluate the chemopreventive effects of CFT-1 green tea infusion (CFT-1) against N-nitrosodiethylamine (NDEA)-induced hepatocarcinogenesis in rats and its mechanisms. The results showed that CFT-1 had a superior inhibitory effect in NDEA-initiated hepatocarcinogenesis compared to that of common tea. CFT-1 significantly reduced the hepatic nodules incidence, size, and number and prevented the hepatic adenoma or hepatocellular carcinoma (HCC) formation. In particular, CFT-1-treated animals had the least incidence of HCC (8.33%) followed by common tea treatment (40.00%) and model control rats (87.50%). CFT-1 treatment significantly ameliorated abnormal liver function enzymes, reduced serum AFP, CEA, TSGF, and TNF-α levels, inhibited the dickkopf-related protein-1 expression, enhanced antioxidant capacity, suppressed the production of livers 8-hydroxy-2'-deoxyguanosine, and regulated hepatic phase I and II xenobiotic-metabolizing enzymes. Transcriptomic analysis of liver tissue suggested that compared to common tea, administration of CFT-1 regulated larger gene sets, which were located in several important pathways of antioxidants, inflammatory network, xenobiotic-metabolizing enzymes, apoptosis, cell proliferation, and metabolism associated with liver tumorigenesis. We identified some genes as potential molecular targets involved in the prevention of CFT-1 and found that CFT-1 inhibited inflammation response, proliferation, and accelerated apoptosis by inhibiting NF-κB and PI3K/Akt pathway. Thus, EGCG-rich CFT-1 green tea might be a potential choice for liver cancer prevention/treatment in the future.

A Standardized Extract of Asparagus officinalis Stem (ETAS®) Ameliorates Cognitive Impairment, Inhibits Amyloid β Deposition via BACE-1 and Normalizes Circadian Rhythm Signaling via MT1 and MT2

The prevalence of cognitive impairments and circadian disturbances increases in the elderly and Alzheimer’s disease (AD) patients. This study investigated the effects of a standardized extract of Asparagus officinalis stem, ETAS^® on cognitive impairments and circadian rhythm status in senescence-accelerated mice prone 8 (SAMP8). ETAS^® consists of two major bioactive constituents: 5-hydroxymethyl-2-furfural (HMF), an abundant constituent, and (S)-asfural, a novel constituent, which is a derivative of HMF. Three-month-old SAMP8 male mice were divided into a control, 200 and 1000 mg/kg BW ETAS^® groups, while senescence-accelerated resistant mice (SAMR1) were used as the normal control. After 12-week feeding, ETAS^® significantly enhanced cognitive performance by an active avoidance test, inhibited the expressions of amyloid-beta precursor protein (APP) and BACE-1 and lowered the accumulation of amyloid β (Aβ) in the brain. ETAS^® also significantly increased neuron number in the suprachiasmatic nucleus (SCN) and normalized the expressions of the melatonin receptor 1 (MT1) and melatonin receptor 2 (MT2). In conclusion, ETAS^® enhances the cognitive ability, inhibits Aβ deposition and normalizes circadian rhythm signaling, suggesting it is beneficial for preventing cognitive impairments and circadian rhythm disturbances in aging.