CCL01, a novel formulation composed of Cuscuta seeds and Lactobacillus paracasei NK112, enhances memory function via nerve growth factor-mediated neurogenesis

Artemisiae Iwayomogii Herba mitigates excessive neuroinflammation and Aβ accumulation by regulating the pro-inflammatory response and autophagy-lysosomal pathway in microglia in 5xFAD mouse model of Alzheimer's disease

Alzheimer's disease (AD) presents a growing societal challenge, driven by an aging population. It is characterized by neurodegeneration linked to β-amyloid (Aβ) and tau protein aggregation. Reactive glial cell-mediated neuroinflammation exacerbates disease progression by facilitating the accumulation of Aβ and impairing its clearance, thus highlighting potential therapeutic targets. Aerial parts of Artemisia iwayomogi (AIH), a kind of mugwort, has been consumed as a medicinal herb in East Asia for relieving inflammation-related diseases. Previously, AIH was found to exert potent inhibitory effects on neuroinflammation. This study aimed to examine whether AIH mitigates AD pathogenesis by regulating neuroinflammation and reducing Aβ deposition. AIH treatment to primary mixed glial cultures attenuated the pro-inflammatory responses evoked by Aβ stimulation. When treated to 5 × familial AD (5xFAD) mice, AIH improved learning and cognitive ability and reduced Aβ burden in the brain. AIH suppressed glial overactivation, as well as inhibited the expressions of pro-inflammatory mediators in the brain. Moreover, AIH regulated AKT signaling and elevated the expression of autophagy-lysosomal mediators in vitro. It was confirmed that lysosome-associated membrane protein 1 (LAMP1) was increased in the Aβ-associated microglia in the mouse hippocampus. Finally, it was observed that tau phosphorylation was alleviated, and synaptic protein expression was increased in AIH-treated 5xFAD mice. Overall, this study demonstrated that AIH ameliorated excessive neuroinflammation and Aβ accumulation by regulating microglial activation and autophagy-lysosomal pathway, thereby suggesting AIH as a promising therapeutic candidate for AD treatment.

Trichosanthis Semen Exerts Neuroprotective Effects in Alzheimer's Disease Models by Inhibiting Amyloid-β Accumulation and Regulating the Akt and ERK Signaling Pathways

Background

Alzheimer's disease (AD), the most common form of dementia, is characterized by memory loss and the abnormal accumulation of senile plaques composed of amyloid-β (Aβ) protein. Trichosanthis Semen (TS) is a traditional herbal medicine used to treat phlegm-related conditions. While TS is recognized for various bioactivities, including anti-neuroinflammatory effects, its ability to attenuate AD remains unknown.

Objective

To evaluate the effects of TS extract (TSE) on neuronal damage, Aβ accumulation, and neuroinflammation in AD models.

Methods

Thioflavin T and western blot assays were used to assess effects on Aβ aggregation in vitro. TS was treated to PC12 cells with Aβ to assess the neuroprotective effects. Memory functions and histological brain features were investigated in TSE-treated 5×FAD transgenic mice and mice with intracerebroventricularly injected Aβ.

Results

TSE disrupted Aβ aggregation and increased the viability of cells and phosphorylation of both protein kinase B (Akt) and extracellular signal-regulated kinase (ERK) in vitro. TSE treatment also suppressed the accumulation of Aβ plaques in the brain of 5×FAD mice, protected neuronal cells in both the subiculum and medial septum, and upregulated Akt/ERK phosphorylation in the hippocampus. Moreover, TSE ameliorated the memory decline and glial overactivation observed in 5×FAD mice. As assessing whether TS affect Aβ-induced neurotoxicity in the Aβ-injected mice, the effects of TS on memory improvement and neuroinflammatory inhibition were confirmed.

Conclusions

TSE disrupted Aβ aggregation, protected neurons against Aβ-induced toxicity, and suppressed neuroinflammation, suggesting that it can suppress the development of AD.

The Role of Bifidobacterium bifidum novaBBF7, Bifidobacterium longum novaBLG2 and Lactobacillus paracasei TJB8 to Improve Mechanisms Linked to Neuronal Cells Protection against Oxidative Condition in a Gut-Brain Axis Model

Despite the identification of several innovative targets for avoiding cognitive decline, there has yet to be a widely accepted approach that deals with minimising the deterioration of cognitive function. In this light, recent studies suggest that regulating the gut-brain axis with probiotics is a potential therapeutic strategy to support brain health. For this reason, in vitro models were used to examine the efficacy of different probiotic combinations to enhance intestinal homeostasis and positively affect the brain. Therefore, the new formulation has been evaluated for its capacity to modify intestinal barrier functions in a 3D in vitro model without any adverse effects and directly impact the mechanisms underlying cognitive function in a gut-brain axis model. According to our findings, B. bifidum novaBBF7 10 mg/mL, B. longum novaBLG2 5 mg/mL and L. paracasei TJB8 10 mg/mL may successfully modify the intestinal barrier and improve SCFA production. Successively, the probiotics studied caused no harm at the neuronal level, as demonstrated by iNOS, mitochondrial potential, and cell viability tests, confirming their safety features and enhancing antioxidant mechanisms and antineuroinflammation activity. Additionally, the damage caused by oxidative stress was also healed, and critical pathways that result in cognitive impairment were changed by synergetic action, supporting the hypothesis that brain ageing and neurodegeneration are slowed down. All these findings demonstrate the ability of probiotics to affect cognitive processes and their ability to sustain the mechanisms underlying cognitive function by acting on intestinal function.

Aerial part of Houttuynia cordata reverses memory impairment by regulating amyloid beta accumulation and neuroinflammation in Alzheimer's disease model

Alzheimer's disease (AD) is the most common neurodegenerative disease characterized by amyloid-β (Aβ) deposition, accompanied by neuroinflammation and memory dysfunction. Houttuyniae Herba (aerial parts of Houttuynia cordata, also known as fish mint; HH), an herbal medicine traditionally used to treat fever, urinary disorders, and pus, is revealed to protect neurons from Aβ toxicity and regulate cholinergic dysfunction in AD models. In this study, we aimed to investigate the effects of HH on excessive accumulation of Aβ followed by neuroinflammation, synaptic degeneration, and memory impairment. Two-month-old 5xFAD transgenic mice were administered HH at 100 mg/kg for 4 months. We observed that HH treatment ameliorated memory impairment and reduced Aβ deposits in the brains of the mice. HH directly inhibited Aβ aggregation in vitro using the Thioflavin T assay and indirectly suppressed the amyloidogenic pathway by increasing alpha-secretase expression in the mice brain. In addition, HH exerted antineuroinflammatory effects by reducing of glial activation and p38 phosphorylation. Moreover, HH treatment increased the expression of synaptophysin, a presynaptic marker protein. Overall, HH alleviates memory impairment in AD by facilitating nonamyloidogenic pathway and inhibiting neuroinflammation. Therefore, we suggest that HH can be a promising herbal drug for patients with AD requiring multifaceted improvement.

Protective effects of CCL01 against Aβ-induced neurotoxicity in 5xFAD transgenic mouse model of Alzheimer's disease

Alzheimer's disease (AD) is the most common dementia characterized by the excessive accumulation of amyloid-beta (Aβ) and tau aggregates, as well as neuronal damage and neuroinflammation. Metabolic disruption in AD has been noticed because metabolite alterations closely correlate with Aβ neuropathology and behavioral phenotypes. Accordingly, controlling various neuropathological processes and metabolic disruption is an efficient therapeutic strategy for AD treatment. In this study, we evaluated the effects of a combination of Cuscuta seeds and Lactobacillus paracasei NK112 (CCL01) on AD neuropathology and altered metabolism in five familial AD (5xFAD) transgenic mice and neuronal cell cultures. First, we observed that CCL01 exerted neuroprotective effects in HT22 hippocampal neurons and primary cultured neurons. CCL01 ameliorated memory decline and protected synapses and neuronal survival in 5xFAD mice. These effects were related to the inhibition of tau phosphorylation. CCL01 also inhibited the activation of mitogen-activated protein kinase (MAPK) signaling and neuroinflammatory processes. Moreover, the metabolite profile-particularly characterized by altered phospholipid metabolism-was significantly changed in the 5xFAD group, while CCL01 partly restored the alteration. Lysophosphatidylcholine (lysoPC), the levels of which were higher in the brains of 5xFAD mice, exerted neurotoxicity in vitro, whereas CCL01 protected neurons from lysoPC-induced toxicity by regulating MAPK signaling. Additionally, CCL01 administration reduced gut inflammation in the 5xFAD mice. In summary, we demonstrated that CCL01 improved the memory function of 5xFAD mice by protecting neurons against Aβ- and lysoPC-induced toxicity through the regulation of MAPK signaling, neuroinflammation, tau phosphorylation, and gut inflammation, suggesting the potential of CCL01 as treatment for AD.

Involvement of Intestinal Microbiota in Adult Neurogenesis and the Expression of Brain-Derived Neurotrophic Factor

Growing evidence suggests a possible involvement of the intestinal microbiota in generating new neurons, but a detailed breakdown of the microbiota composition is lacking. In this report, we systematically reviewed preclinical rodent reports addressing the connection between the composition of the intestinal microbiota and neurogenesis and neurogenesis-affecting neurotrophins in the hippocampus. Various changes in bacterial composition from low taxonomic resolution at the phylum level to high taxonomic resolution at the species level were identified. As for neurogenesis, studies predominantly used doublecortin (DCX) as a marker of newly formed neurons or bromodeoxyuridine (BrdU) as a marker of proliferation. Brain-derived neurotrophic factor (BDNF) was the only neurotrophin found researched in relation to the intestinal microbiota. Phylum Actinobacteria, genus Bifidobacterium and genus Lactobacillus found the strongest positive. In contrast, phylum Firmicutes, phylum Bacteroidetes, and family Enterobacteriaceae, as well as germ-free status, showed the strongest negative correlation towards neurogenesis or BDNF mRNA expression. Age, short-chain fatty acids (SCFA), obesity, and chronic stress were recurring topics in all studies identified. Overall, these findings add to the existing evidence of a connection between microbiota and processes in the brain. To better understand this interaction, further investigation based on analyses of higher taxonomic resolution and clinical studies would be a gain to the matter.

The novel anti-neuroinflammatory functional food CCL01, a mixture of Cuscuta seed extracts and Lactobacillus paracasei NK112

Neuroinflammation, which occurs due to microglia, is related to the pathogenesis of neurodegenerative disorders. Recently, the development of functional foods that down-regulate over-activated microglial cells to prevent the progression of neurodegenerative disorders has been proposed, since over-activated microglia induce a chronic source of neurotoxic factors and reduce neuronal survival. Thus, the anti-neuroinflammatory effects of a functional food mixture (CCL01) including Cuscuta seeds and Lactobacillus paracasei NK112 on lipopolysaccharide (LPS)-induced experimental models were investigated. In LPS-induced in vitro models, the expression levels of inflammatory mediators (e.g., inducible nitric oxide synthase, cyclooxygenase-2, nitric oxide, and prostaglandin E2) and pro-inflammatory cytokines (e.g., tumor necrosis factor-α, interleukin (IL)-1β, and IL-6) were decreased upon CCL01 treatment. CCL01 showed an anti-neuroinflammatory effect in LPS-induced microglial cells via the inhibition of the mitogen-activated protein kinase (MAPK)/nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway and the activation of the nuclear factor erythroid-2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. In the LPS-treated in vivo mouse models, the increased expression of ionized calcium binding adaptor molecule 1 (Iba-1), which indicates microglial activity, was markedly decreased upon treatment with CCL01 (50 and 200 mg kg^-1) in the hippocampus and cortex areas of the mouse brains in comparison with the LPS-injected group. In addition, the groups to which CCL01 was administered had significantly decreased plasma levels of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 in the LPS-injected mouse models. Our data suggest that CCL01 may be a potential anti-neuroinflammatory agent that can prevent microglia overactivation, and it could be useful for developing functional foods.