The primary aim of this research is to delve comprehensively into the promising neuroprotective advantages offered by the combination of fermented blueberry and black rice (FBBR), with the goal of alleviating the detrimental effects caused by exposure to PM2.5 on neuronal cells and cognitive function. PM2.5 is widely recognized for its ability to initiate neuroinflammation, oxidative stress, and cognitive decline, all of which play significant roles in the advancement of neurodegenerative disorders [
1,
19,
20]. This investigation is focused on revealing the intricate underlying mechanisms that give rise to the protective properties exhibited by FBBR. The initiation of this inquiry involved a meticulous evaluation of the impact of PM2.5 exposure on SH-SY5Y cells. At a concentration of 100 µg/mL, PM2.5 notably undermined cell viability and triggered a substantial increase in the production of nitric oxide (NO). This highlights the potent capacity of PM2.5 to induce oxidative stress and inflict significant damage to cellular structures. Encouragingly, treatment with FBBR at the same concentration adeptly restored cell viability to a considerable extent and effectively mitigated the excessive production of NO. These results underscore the considerable potential of FBBR in conferring robust neuroprotection. By effectively countering the adverse effects of PM2.5 on neuronal cells and cognitive function, FBBR holds great promise as a natural intervention to mitigate the progression of neurodegenerative disorders. This study contributes to a deeper understanding of the potential benefits of FBBR and sheds light on its possible role in promoting brain health in the face of environmental challenges like PM2.5 exposure.
The study's scope was expanded to encompass an evaluation of FBBR's effects on mice models exposed to PM2.5. The evident cognitive impairment resulting from PM2.5 exposure was verified through the utilization of both the Morris Water Maze and Y-Maze tests, illuminating the substantial extent of cognitive decline induced by the pollutant [
1,
21]. However, the administration of FBBR displayed a remarkable ability to ameliorate this cognitive impairment, effectively reinstating the cognitive performance of the treated mice to a level closely resembling that of the control group. In the context of neuroinflammation, a pivotal aspect of the study, mice subjected to PM2.5 exposure exhibited a prominent elevation in pro-inflammatory markers. These markers serve as reliable indicators of heightened inflammation within the brain. Impressively, the implementation of FBBR treatment exerted a significant modulating influence on the escalated levels of these inflammatory cytokines. This compelling outcome underscores the potent capacity of FBBR to effectively alleviate the neuroinflammatory response triggered by exposure to PM2.5, indicating its potential as a valuable intervention in mitigating the adverse neurological effects associated with environmental pollutant exposure [
17].
Exposure to PM2.5 resulted in the notable upregulation of key inflammatory markers, including iNOS, COX-2, and IL-6, within SH-SY5Y cells. What adds to the intrigue is the compelling response observed upon the application of FBBR treatment. Demonstrating its anti-inflammatory prowess, FBBR impressively orchestrated the downregulation of iNOS, COX-2, and IL-6 expressions. This intriguing ability underscores FBBR's potential in curbing inflammatory responses. Beyond its anti-inflammatory effects, FBBR revealed its capacity to foster neuroprotection through its modulation of apoptotic markers. In a remarkable display, FBBR not only diminished pro-apoptotic markers but also exerted a positive influence on anti-apoptotic regulators like Bcl-2 and BDNF. The pivotal BAX/Bcl-2 ratio, a decisive factor in determining cellular survival, exhibited a favorable shift under the influence of FBBR. This implies the potential cryoprotective role of FBBR, a notion substantiated by previous studies [
2,
21,
22]. Neuroinflammation is a pivotal contributor to neurodegenerative diseases [
3,
23]. In fact, PM2.5-induced neuroinflammation was conspicuously observed in brain regions intricately linked with cognition, such as the cerebral cortex and hippocampus. Within these regions, the expression of pivotal inflammatory biomarkers, including iNOS, COX-2, and TNF-α, experienced marked elevation following PM2.5 exposure. Here again, the potential of FBBR shone through, as it adeptly counteracted these neuroinflammatory responses. A significant highlight is the restoration of IL-1β, a crucial inflammatory mediator, to its normal levels through FBBR treatment. This restoration strongly suggests the therapeutic potential of FBBR in mitigating neuroinflammatory responses associated with exposure to PM2.5, a finding with far-reaching implications for addressing the neurodegenerative risks posed by environmental factors [
24]. FBBR contains major and effective bioactive compounds as shown in our previous study [
14] such as gallic acid, chlorogenic acid, rutin, quercetin, resveratrol, syringic acid, and kuromanine, which showed pivotal role against neurodegeneration[
12,
25]. Gallic acid, chlorogenic acid, rutin, quercetin, resveratrol, syringic acid, and kuromanine are renowned for their antioxidant and anti-inflammatory properties. They have demonstrated the ability to shield against oxidative stress and neuroinflammation, thereby holding promise in potentially reducing the risk of neurodegenerative diseases [
26,
27,
28].