Effects of gut microbiota on neurodegenerative diseases.

A progressive degradation of the brain's structure and function, which results in a reduction in cognitive and motor skills, characterizes neurodegenerative diseases (NDs) such as Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic lateral sclerosis (ALS), and Huntington's disease (HD). The morbidity linked to NDs is growing, which poses a severe threat to human being's mental and physical ability to live well. The gut-brain axis (GBA) is now known to have a crucial role in the emergence of NDs. The gut microbiota is a conduit for the GBA, a two-way communication system between the gut and the brain. The myriad microorganisms that make up the gut microbiota can affect brain physiology by transmitting numerous microbial chemicals from the gut to the brain via the GBA or neurological system. The synthesis of neurotransmitters, the immunological response, and the metabolism of lipids and glucose have all been demonstrated to be impacted by alterations in the gut microbiota, such as an imbalance of helpful and harmful bacteria. In order to develop innovative interventions and clinical therapies for NDs, it is crucial to comprehend the participation of the gut microbiota in these conditions. In addition to using antibiotics and other drugs to target particular bacterial species that may be a factor in NDs, this also includes using probiotics and other fecal microbiota transplantation to maintain a healthy gut microbiota. In conclusion, the examination of the GBA can aid in understanding the etiology and development of NDs, which may benefit the improvement of clinical treatments for these disorders and ND interventions. This review indicates existing knowledge about the involvement of microbiota present in the gut in NDs and potential treatment options.

The Future of Precision Medicine in the Cure of Alzheimer's Disease.

This decade has seen the beginning of ground-breaking conceptual shifts in the research of Alzheimer's disease (AD), which acknowledges risk elements and the evolving wide spectrum of complicated underlying pathophysiology among the range of diverse neurodegenerative diseases. Significant improvements in diagnosis, treatments, and mitigation of AD are likely to result from the development and application of a comprehensive approach to precision medicine (PM), as is the case with several other diseases. This strategy will probably be based on the achievements made in more sophisticated research areas, including cancer. PM will require the direct integration of neurology, neuroscience, and psychiatry into a paradigm of the healthcare field that turns away from the isolated method. PM is biomarker-guided treatment at a systems level that incorporates findings of the thorough pathophysiology of neurodegenerative disorders as well as methodological developments. Comprehensive examination and categorization of interrelated and convergent disease processes, an explanation of the genomic and epigenetic drivers, a description of the spatial and temporal paths of natural history, biological markers, and risk markers, as well as aspects about the regulation, and the ethical, governmental, and sociocultural repercussions of findings at a subclinical level all require clarification and realistic execution. Advances toward a comprehensive systems-based approach to PM may finally usher in a new era of scientific and technical achievement that will help to end the complications of AD.

Fisetin provides neuroprotection in pentylenetetrazole-induced cognition impairment by upregulating CREB/BDNF.

OBJECTIVES: Fisetin is a flavonoid molecule known to be neuroprotective by its multiple mechanisms. The present study was designed to explore the effect of fisetin in the pentylenetetrazole (PTZ) kindling-induced cognitive dysfunction in mice. METHODS: Kindling was established by the intraperitoneal administration of PTZ in a subconvulsive dose (25 mg/kg). Mice were administered fisetin (5, 10, and 20 mg/kg, p.o.) to study its probable cognition-enhancing effect. The kindled mice were evaluated for cognition using behavioral tests-elevated plus maze and passive avoidance response. Then, the oxidative stress markers, gene expressions and neurotransmitters levels were estimated in the hippocampus and cortex of mice. RESULTS: Passive avoidance response and elevated plus maze paradigms showed that fisetin administration improved the cognitive function in kindled mice. The increased levels of lipid peroxidation and protein carbonyl were modulated upon fisetin administration through increasing the levels of antioxidants (reduced glutathione, glutathione reductase, glutathione peroxidase, superoxide dismutase, and catalase) in the hippocampus and cortex of kindled mice. Upregulated gene expressions of cAMP response element-binding protein (CREB) and brain-derived neurotrophic factor (BDNF) were observed in the hippocampus and cortex of fisetin-administered mice which play a crucial role in cognitive function. Furthermore, alterations of neurotransmitter levels (dopamine, GABA, and glutamate) and acetylcholinesterase (AchE) were ameliorated by fisetin administration in the hippocampus and cortex of kindled mice. CONCLUSION: Our findings suggest a therapeutic potential of fisetin against cognitive dysfunction associated with PTZ-induced kindling.

Chemotherapeutic Role of Polyphenols Present in Ocimum sanctum.

Ocimum sanctum is a sacred herb of India and is commonly known as 'Tulsi' or 'Holy Basil' in regional languages of the country. Various parts of O. sanctum are recognised to have remarkable therapeutic efficacy, and are therefore used in Indian traditional medicine system, Ayurveda. Scientific studies have shown that O. sanctum has a range of pharmacological activities. The presence of a substantial amount of polyphenols in O. sanctum could be the reason for its excellent bioactivity. Polyphenols are used to prevent or treat oncologic diseases due to their anti-cancer effects, which are related to activation of apoptotic signaling, cell cycle arrest, binding ability with membrane receptors, and potential effects on immunomodulation and epigenetic mechanisms. The poor bioavailability of polyphenols restricts their clinical use. The application of nanonization has been implemented to improve their bioavailability, penetrability, and prolong their anticancer action. The present review analyses the recent preclinical studies related to the chemo-preventive and therapeutic potential of polyphenols present in O. sanctum. Moreover, the current article also examines in-depth the biochemical and molecular mechanisms involved in the antineoplastic actions of the considered polyphenols.

Nanoencapsulation of Polyphenols as Drugs and Supplements for Enhancing Therapeutic Profile - A Review.

Polyphenolic phytoconstituents have been widely in use worldwide for ages and are categorised as secondary metabolites of plants. The application of polyphenols such as quercetin, resveratrol, curcumin as nutritional supplements has been researched widely. The use of polyphenols and specifically quercetin, for improving memory and mental endurance has shown significant effects among rats. Even though similar results have not been resonated among humans, but preclinical results have encouraged researchers to explore other polyphenols to study the effects as supplements among athletes. The phytopharmacological research has elucidated the use of natural polyphenols to prevent and treat various physiological and metabolic disorders owing to their free radical scavenging properties, anti-inflammatory, anti-cancer, and immunomodulatory effects. In- -spite of the tremendous pharmacological profile, one of the most dominant problem regarding the use of polyphenolic compounds is their low bioavailability. Nanonization is considered as one of the most prominent approaches among many. This article aims to review and discuss the molecular mechanisms of recently developed nanocarrier-based drug delivery systems for polyphenols and their application as drugs and supplements. Nanoformulations of natural polyphenols as bioactive agents, such as quercetin, kaempferol, fisetin, rutin, hesperetin, and naringenin epigalloccatechin- 3-gallate, genistein, ellagic acid, gallic acid, chlorogenic acid, ferulic acid, curcuminoids, and stilbenes is expected to have better efficacy. These delivery systems are expected to provide higher penetrability of polyphenols at cellular levels and exhibit a controlled release of the drugs. It is widely accepted that natural polyphenols do demonstrate significant therapeutic effects. However, the hindrances in their absorption, specificity, and bioavailability can be overcome using nanotechnology.

Neuroprotective Effect of Fisetin Through Suppression of IL-1R/TLR Axis and Apoptosis in Pentylenetetrazole-Induced Kindling in Mice.

Epilepsy is a complex neurological disorder, characterized by frequent electrical activity in brain regions. Inflammation and apoptosis cascade activation are serious neurological sequelae during seizures. Fisetin (3, 3',4',7-tetrahydroxyflavone), a flavonoid molecule, is considered for its effective anti-inflammatory and anti-apoptotic properties. This study investigated the neuroprotective effect of fisetin on experimental epilepsy. For acute studies, increasing current electroshock (ICES) and pentylenetetrazole (PTZ)-induced seizure tests were performed to evaluate the antiseizure activity of fisetin. For the chronic study, the kindling model was established by the administration of PTZ in subconvulsive dose (25 mg/kg, i.p.). Mice were treated with fisetin (5, 10, and 20 mg/kg, p.o.) to study its probable antiseizure mechanism. The kindled mice were evaluated for seizure scores. Their hippocampus and cortex were assessed for neuronal damage, inflammation, and apoptosis. Histological alterations were observed in the hippocampus of the experimental mice. Levels of high mobility group box 1 (HMGB1), Toll-like receptor-4 (TLR-4), interleukin-1 receptor 1 (IL-1R1), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were assessed in the hippocampus and cortex by ELISA. The immunoreactivity and mRNA expressions of nuclear factor-κB (NF-κB), cyclooxygenase-2 (COX-2), cytochrome C, and caspase-3 were quantified by immunohistochemical analysis and real-time PCR. Phosphorylation ELISA was performed to evaluate AkT/mTOR (mammalian target of rapamycin) activation in the hippocampus and cortex of the kindled mice. The results showed that fisetin administration increased the seizure threshold current (STC) in the ICES test. In PTZ-induced seizures, fisetin administration increased the latency for myoclonic jerks (MJs) and generalized seizures (GSs). In the PTZ-induced kindling model, fisetin administration dose-dependently suppressed the development of kindling and the associated neuronal damage in the experimental mice. Further, fisetin administration ameliorated kindling-induced neuroinflammation as evident from decreased levels of HMGB1, TLR-4, IL-1R1, IL-1ß, IL-6, and TNF-α in the hippocampus and cortex of the kindled mice. Also, the immunoreactivity and mRNA expressions of inflammatory molecules, NF-κB, and COX-2 were decreased with fisetin administration in the kindled animals. Decreased phosphorylation of the AkT/mTOR pathway was reported with fisetin administration in the hippocampus and cortex of the kindled mice. The immunoreactivity and mRNA expressions of apoptotic molecules, cytochrome C, and caspase-3 were attenuated upon fisetin administration. The findings suggest that fisetin shows a neuroprotective effect by suppressing the release of inflammatory and apoptosis molecules and attenuating histological alterations during experimental epilepsy.

Elevated urinary IL-36α and IL-18 levels are associated with diabetic nephropathy in patients with type 2 diabetes mellitus.

BACKGROUND: Inflammatory cytokines have been reported to be pathogenic factors for the development and progression of diabetic nephropathy (DN). Interleukin (IL)-36α is a newly discovered member of the IL-1 cytokine family that has been implicated in animal models of renal impairment. However, little is known about the role of IL-36α in DN in humans. The purpose of the present study was to assess the levels of IL-36α and IL-18 in type 2 diabetic patients (T2DM) patients with and without DN. METHODS: Subjects were divided into 3 groups: Control (N.=20), T2DM without DN (N.=30), and T2DM with DN (N.=30). Urinary IL-36α and IL-18 levels were assessed using ELISA. Correlation analysis was performed to determine the association of the IL levels with clinical markers of T2DM and DN. RESULTS: IL-36α and IL-18 levels were significantly elevated in T2DM patients with DN, when compared to T2DM patients without DN (P<0.0001, P=0.0025, respectively) and controls (P<0.0001, for both). IL-36α levels showed a positive correlation with urinary albumin excretion (r=0.754, P<0.0001), HbA1c (r=0.433, P=0.0168), fasting plasma glucose (r=0.433, P=0.0168) and negative correlation with glomerular filtration rate (r=-0.852 P<0.0001). CONCLUSIONS: The results highlighted the association of IL-36α with DN. However, further extensive studies are suggested for evaluating the association.

Heavy Metal-Induced Systemic Dysfunction Attenuated by Tannic Acid.

Lead toxicity is a major public health concern. This study was designed to investigate the effects of oral administration of tannic acid (TA) on lead acetate (LA)-induced oxidative stress in rat liver and kidney. Rats were treated with 50 mg/kg body weight of TA against LA-induced oxidative stress 3 times/week for 2 weeks. At a rate of 50 mg/kg of body weight, LA was given intraperitoneally 3 times/week for 2 weeks. Results show significantly elevated levels of oxidative stress markers observed in LA-treated rats, whereas significant depletion in the activity of nonenzymatic and enzymatic antioxidants as well as histological changes were observed in LA-treated rat liver and kidney. TA treatment significantly attenuated the altered levels of oxidative stress biomarkers for nonenzymatic and enzymatic antioxidants. We demonstrated that TA exhibits potent antioxidant and protected against oxidative damage in rat liver and kidney induced by LA treatment. These findings were further supported by histopathological findings in liver and kidney showing that TA protected tissue from the deleterious effects of LA treatment. These outcomes suggest that the consumption of TA may confer a protective effect against lead intoxication through its antioxidative effect.