Curcumin, Gut Microbiota, and Neuroprotection

Investigation of the effects of curcumin and piperine on cyclophosphamide-induced brain injury in rats

Cyclophosphamide (CP) is an antineoplastic drug widely used in chemotherapy. Curcumin (CUR) and piperine (PP) show a protective effect on neurodegenerative and neurological diseases. This research was designed to measure several biochemical parameters in the brain tissue of CP-applied rats to investigate the impact of combined CUR-PP administration. The study evaluated six groups of eight rats: Group 1 was the control; Groups 2 and 3 were administered 200 or 300 mg/kg CUR-PP via oral gavage; Group 4 received only 200 mg/kg CP on day 1; Groups 5 and 6 received CP + CUR-PP for 7 days. Data from all parameters indicated that CP caused brain damage. Phosphorylated TAU (pTAU), amyloid-beta peptide 1-42 (Aβ1-42), glutamate (GLU), and gamma amino butyric acid (GABA) parameters were the same in Groups 4, 5, and 6. On the other hand, 8-hydroxy-2-deoxyguanosine (8-OHdG), nitric oxide (NO), interleukin-6 (IL-6), nuclear factor kappa beta (NF-kβ), malondialdehyde (MDA), and tumor necrosis factor-alpha (TNF-α) levels in the CP + CUR-PP groups were lower than those in the CP group (p < 0.05). However, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and reduced glutathione (GSH) parameters were higher in the CP + CUR-PP groups compared to the CP group (p < 0.05). It is thought that the similarity of Groups 5 and 6 with Group 4 in Aβ1-42, pTAU, GLU, and GABA parameters hinder the determination of treatment protection however, they might have a therapeutic effect if the applied dose or study duration were changed. This study attempted to evaluate the effects of a CUR-PP combination on CP-induced brain damage in rats by measuring biochemical parameters and performing histopathological examinations. Based on the findings, this CUR-PP combination could be considered an alternative medicine option in cases with conditions similar to those evaluated in this study.

Astragalus mongholicus Bunge and Curcuma aromatica Salisb. modulate gut microbiome and bile acid metabolism to inhibit colon cancer progression

Introduction

Alterations in the gut microbiome and bile acid metabolism are known to play a role in the development and progression of colon cancer. Medicinal plants like Astragalus mongholicus Bunge and Curcuma aromatica Salisb. (AC) have shown preferable therapeutic effect on cancer therapy, especially digestive tract tumors like colon cancer. However, the precise mechanisms of AC inhibiting colon cancer, particularly in relation to the gut microbiome and bile acid dynamics, are not fully understood.

Methods

Our research aimed to investigate the anti-tumor properties of AC in mice with CT26 colon cancer and further investigate its underlying mechanism via intestinal microbiota. The size and pathological changes of solid tumors in colon cancer are used to evaluate the inhibitory effect of AC on colon cancer. Metagenomics and 16s rRNA gene sequencing were employed to clarify the dysbiosis in the gut microbiome of colon cancer and its impact on colon cancer. The levels of bile acids (BAs) in the feces of mice from each group were measured using UPLC-Qtrap-MS/MS.

Results

AC effectively suppressed the growth of colon cancer and reduced histological damage. Notably, AC treatment led to changes in the gut microbiome composition, with a decrease in pathogenic species like Citrobacter and Candidatus_Arthromitus, and an increase in beneficial microbial populations including Adlercreutzia, Lachnospiraceae_UCG-001, and Parvibacter. Additionally, AC altered bile acid profiles, resulting in a significant decrease in pro-carcinogenic bile acids such as deoxycholic acid (DCA) and lithocholic acid (LCA), while increasing the concentration of the cancer-inhibitory bile acid, ursodeoxycholic acid (UDCA). Tracking and analyzing the data, AC may mainly upregulate FabG and baiA genes by increasing the relative abundance of Adlercreutzia and Parvibacter bacteria, which promoting the metabolism of pro-carcinogenic LCA.

Discussion

These findings provide strong evidence supporting the role of AC in regulating gut microbiome-mediated bile acid metabolism, which is crucial in impeding the progression of colon cancer.

Modulatory Effects of Phytochemicals on Gut-Brain Axis: Therapeutic Implication

This article explores the potential therapeutic implications of phytochemicals on the gut-brain axis (GBA), which serves as a communication network between the central nervous system and the enteric nervous system. Phytochemicals, which are compounds derived from plants, have been shown to interact with the gut microbiota, immune system, and neurotransmitter systems, thereby influencing brain function. Phytochemicals such as polyphenols, carotenoids, flavonoids, and terpenoids have been identified as having potential therapeutic implications for various neurological disorders. The GBA plays a critical role in the development and progression of various neurological disorders, including Parkinson's disease, multiple sclerosis, depression, anxiety, and autism spectrum disorders. Dysbiosis, or an imbalance in gut microbiota composition, has been associated with a range of neurological disorders, suggesting that modulating the gut microbiota may have potential therapeutic implications for these conditions. Although these findings are promising, further research is needed to elucidate the optimal use of phytochemicals in neurological disorder treatment, as well as their potential interactions with other medications. The literature review search was conducted using predefined search terms such as phytochemicals, gut-brain axis, neurodegenerative, and Parkinson in PubMed, Embase, and the Cochrane library.

Hormetic Nutrition and Redox Regulation in Gut-Brain Axis Disorders

The antioxidant and anti-inflammatory effects of hormetic nutrition for enhancing stress resilience and overall human health have received much attention. Recently, the gut-brain axis has attracted prominent interest for preventing and therapeutically impacting neuropathologies and gastrointestinal diseases. Polyphenols and polyphenol-combined nanoparticles in synergy with probiotics have shown to improve gut bioavailability and blood-brain barrier (BBB) permeability, thus inhibiting the oxidative stress, metabolic dysfunction and inflammation linked to gut dysbiosis and ultimately the onset and progression of central nervous system (CNS) disorders. In accordance with hormesis, polyphenols display biphasic dose-response effects by activating at a low dose the Nrf2 pathway resulting in the upregulation of antioxidant vitagenes, as in the case of heme oxygenase-1 upregulated by hidrox® or curcumin and sirtuin-1 activated by resveratrol to inhibit reactive oxygen species (ROS) overproduction, microbiota dysfunction and neurotoxic damage. Importantly, modulation of the composition and function of the gut microbiota through polyphenols and/or probiotics enhances the abundance of beneficial bacteria and can prevent and treat Alzheimer's disease and other neurological disorders. Interestingly, dysregulation of the Nrf2 pathway in the gut and the brain can exacerbate selective susceptibility under neuroinflammatory conditions to CNS disorders due to the high vulnerability of vagal sensory neurons to oxidative stress. Herein, we aimed to discuss hormetic nutrients, including polyphenols and/or probiotics, targeting the Nrf2 pathway and vitagenes for the development of promising neuroprotective and therapeutic strategies to suppress oxidative stress, inflammation and microbiota deregulation, and consequently improve cognitive performance and brain health. In this review, we also explore interactions of the gut-brain axis based on sophisticated and cutting-edge technologies for novel anti-neuroinflammatory approaches and personalized nutritional therapies.

Curcumin Supplementation Improves Growth Performance and Anticoccidial Index by Improving the Antioxidant Capacity, Inhibiting Inflammatory Responses, and Maintaining Intestinal Barrier Function in Eimeria tenella-Infected Broilers

This study was conducted to investigate the effects of dietary curcumin supplementation on growth performance, anticoccidial index, antioxidant capacity, intestinal inflammation, and cecum microbiota in broilers infected with Eimeria tenella. A total of 234 one-day-old broilers were categorized into three treatments, with six replicates per treatment containing 13 broilers each. The three treatments included the control group, Eimeria tenella group, and Eimeria tenella + curcumin (200 mg/kg) group. The feeding trial lasted for 42 days, during which the broilers were orally administered with 0.9% saline or 5 × 104Eimeria tenella oocysts on day 14 of the study. On day 17 and day 21, one bird per replicate was selected for slaughtering. Results indicated an increased survival rate and anticoccidial index and improved productive performance in coccidia-infected broilers with curcumin supplementation. Furthermore, curcumin enhanced the serum antioxidant capacity in Eimeria tenella-infected broilers, evidenced by increased serum catalase activity (3d, 7d), as well as decreased malondialdehyde level (3d, 7d) and nitric oxide synthase activity (7d) (p < 0.05). Curcumin also improved intestinal inflammation and barrier function, evidenced by the downregulation of interleukin (IL)-1β (3d, 7d), TNF-alpha (TNF-α) (3d, 7d), and IL-2 (7d) and the up-regulated mRNA levels of claudin-1 (7d), zonula occludens (ZO-1; 3d, 7d), and occludin (3d, 7d) in the ceca of infected broilers (p < 0.05). Eimeria tenella infection significantly disrupted cecum microbial balance, but curcumin did not alleviate cecum microbial disorder in broilers infected with Eimeria tenella. Collectively, curcumin supplementation enhanced growth performance and anticoccidial index in Eimeria tenella-infected broilers via improving antioxidant ability and cecum inflammation without affecting cecum microbiota.

Sports-Related Gastrointestinal Disorders: From the Microbiota to the Possible Role of Nutraceuticals, a Narrative Analysis

Intense physical exercise can be related to a significant incidence of gastrointestinal symptoms, with a prevalence documented in the literature above 80%, especially for more intense forms such as running. This is in an initial phase due to the distancing of the flow of blood from the digestive system to the skeletal muscle and thermoregulatory systems, and secondarily to sympathetic nervous activation and hormonal response with alteration of intestinal motility, transit, and nutrient absorption capacity. The sum of these effects results in a localized inflammatory process with disruption of the intestinal microbiota and, in the long term, systemic inflammation. The most frequent early symptoms include abdominal cramps, flatulence, the urge to defecate, rectal bleeding, diarrhea, nausea, vomiting, regurgitation, chest pain, heartburn, and belching. Promoting the stability of the microbiota can contribute to the maintenance of correct intestinal permeability and functionality, with better control of these symptoms. The literature documents various acute and chronic alterations of the microbiota following the practice of different types of activities. Several nutraceuticals can have functional effects on the control of inflammatory dynamics and the stability of the microbiota, exerting both nutraceutical and prebiotic effects. In particular, curcumin, green tea catechins, boswellia, berberine, and cranberry PACs can show functional characteristics in the management of these situations. This narrative review will describe its application potential.

Advances in Nanocarrier Systems for Overcoming Formulation Challenges of Curcumin: Current Insights

Curcumin, an organic phenolic molecule that is extracted from the rhizomes of Curcuma longa Linn, has undergone extensive evaluation for its diverse biological activities in both animals and humans. Despite its favorable characteristics, curcumin encounters various formulation challenges and stability issues that can be effectively addressed through the application of nanotechnology. Nano-based techniques specifically focused on enhancing solubility, bioavailability, and therapeutic efficacy while mitigating toxicity, have been explored for curcumin. This review systematically presents information on the improvement of curcumin's beneficial properties when incorporated, either individually or in conjunction with other drugs, into diverse nanosystems such as liposomes, nanoemulsions, polymeric micelles, dendrimers, polymeric nanoparticles, solid-lipid nanoparticles, and nanostructured lipid carriers. Additionally, the review examines ongoing clinical trials and recently granted patents, offering a thorough overview of the dynamic landscape in curcumin delivery. Researchers are currently exploring nanocarriers with crucial features such as surface modification, substantial loading capacity, biodegradability, compatibility, and autonomous targeting specificity and selectivity. Nevertheless, the utilization of nanocarriers for curcumin delivery is still in its initial phases, with regulatory approval pending and persistent safety concerns surrounding their use.

Polyphenolic Compounds: Orchestrating Intestinal Microbiota Harmony during Aging

In the aging process, physiological decline occurs, posing a substantial threat to the physical and mental well-being of the elderly and contributing to the onset of age-related diseases. While traditional perspectives considered the maintenance of life as influenced by a myriad of factors, including environmental, genetic, epigenetic, and lifestyle elements such as exercise and diet, the pivotal role of symbiotic microorganisms had been understated. Presently, it is acknowledged that the intestinal microbiota plays a profound role in overall health by signaling to both the central and peripheral nervous systems, as well as other distant organs. Disruption in this bidirectional communication between bacteria and the host results in dysbiosis, fostering the development of various diseases, including neurological disorders, cardiovascular diseases, and cancer. This review aims to delve into the intricate biological mechanisms underpinning dysbiosis associated with aging and the clinical ramifications of such dysregulation. Furthermore, we aspire to explore bioactive compounds endowed with functional properties capable of modulating and restoring balance in this aging-related dysbiotic process through epigenetics alterations.

The Modulatory Effects of Curcumin on the Gut Microbiota: A Potential Strategy for Disease Treatment and Health Promotion

Curcumin (CUR) is a lipophilic natural polyphenol that can be isolated from the rhizome of turmeric. Studies have proposed that CUR possesses a variety of biological activities. Due to its anti-inflammatory and antioxidant properties, CUR shows promise in the treatment of inflammatory bowel disease, while its anti-obesity effects make it a potential therapeutic agent in the management of obesity. In addition, curcumin's ability to prevent atherosclerosis and its cardiovascular benefits further expand its potential application in the treatment of cardiovascular disease. Nevertheless, owing to the limited bioavailability of CUR, it is difficult to validate its specific mechanism of action in the treatment of diseases. However, the restricted bioavailability of CUR makes it challenging to confirm its precise mode of action in disease treatment. Recent research indicates that the oral intake of curcumin may lead to elevated levels of residual curcumin in the gastrointestinal system, hinting at curcumin's potential to directly influence gut microbiota. Furthermore, the ecological dysregulation of the gut microbiota has been shown to be critical in the pathogenesis of human diseases. This review summarizes the impact of gut dysbiosis on host health and the various ways in which curcumin modulates dysbiosis and ameliorates various diseases caused by it through the administration of curcumin.

Effects of dietary chlorogenic acid on cecal microbiota and metabolites in broilers during lipopolysaccharide-induced immune stress

Aims

The aim of this study was to investigate the effects of chlorogenic acid (CGA) on the intestinal microorganisms and metabolites in broilers during lipopolysaccharide (LPS)-induced immune stress.

Methods

A total of 312 one-day-old Arbor Acres (AA) broilers were randomly allocated to four groups with six replicates per group and 13 broilers per replicate: (1) MS group (injected with saline and fed the basal diet); (2) ML group (injected with 0.5 mg LPS/kg and fed the basal diet); (3) MA group (injected with 0.5 mg LPS/kg and fed the basal diet supplemented with 1,000 mg/kg CGA); and (4) MB group (injected with saline and fed the basal diet supplemented with 1,000 mg/kg CGA).

Results

The results showed that the abundance of beneficial bacteria such as Bacteroidetes in the MB group was significantly higher than that in MS group, while the abundance of pathogenic bacteria such as Streptococcaceae was significantly decreased in the MB group. The addition of CGA significantly inhibited the increase of the abundance of harmful bacteria such as Streptococcaceae, Proteobacteria and Pseudomonas caused by LPS stress. The population of butyric acid-producing bacteria such as Lachnospiraceae and Coprococcus and beneficial bacteria such as Coriobacteriaceae in the MA group increased significantly. Non-targeted metabonomic analysis showed that LPS stress significantly upregulated the 12-keto-tetrahydroleukotriene B4, riboflavin and mannitol. Indole-3-acetate, xanthurenic acid, L-formylkynurenine, pyrrole-2-carboxylic acid and L-glutamic acid were significantly down-regulated, indicating that LPS activated inflammation and oxidation in broilers, resulting in intestinal barrier damage. The addition of CGA to the diet of LPS-stimulated broilers significantly decreased 12-keto-tetrahydro-leukotriene B4 and leukotriene F4 in arachidonic acid metabolism and riboflavin and mannitol in ABC transporters, and significantly increased N-acetyl-L-glutamate 5-semialdehyde in the biosynthesis of amino acids and arginine, The presence of pyrrole-2-carboxylic acid in D-amino acid metabolism and the cecal metabolites, indolelactic acid, xanthurenic acid and L-kynurenine, indicated that CGA could reduce the inflammatory response induced by immune stress, enhance intestinal barrier function, and boost antioxidant capacity.

Conclusion

We conclude that CGA can have a beneficial effect on broilers by positively altering the balance of intestinal microorganisms and their metabolites to inhibit intestinal inflammation and barrier damage caused by immune stress.

Amelioration of the brain structural connectivity is accompanied with changes of gut microbiota in a tuberous sclerosis complex mouse model

Tuberous sclerosis complex (TSC) is a genetic disease that causes benign tumors and dysfunctions in many organs, including the brain. Aside from the brain malformations, many individuals with TSC exhibit neuropsychiatric symptoms. Among these symptoms, autism spectrum disorder (ASD) is one of the most common co-morbidities, affecting up to 60% of the population. Past neuroimaging studies strongly suggested that the impairments in brain connectivity contribute to ASD, whether or not TSC-related. Specifically, the tract-based diffusion tensor imaging (DTI) analysis provides information on the fiber integrity and has been used to study the neuropathological changes in the white matter of TSC patients with ASD symptoms. In our previous study, curcumin, a diet-derived mTOR inhibitor has been shown to effectively mitigate learning and memory deficits and anxiety-like behavior in Tsc2+/- mice via inhibiting astroglial proliferation. Recently, gut microbiota, which is greatly influenced by the diet, has been considered to play an important role in regulating several components of the central nervous system, including glial functions. In this study, we showed that the abnormal social behavior in the Tsc2+/- mice can be ameliorated by the dietary curcumin treatment. Second, using tract-based DTI analysis, we found that the Tsc2+/- mice exhibited altered fractional anisotropy, axial and radial diffusivities of axonal bundles connecting the prefrontal cortex, nucleus accumbens, hypothalamus, and amygdala, indicating a decreased brain network. Third, the dietary curcumin treatment improved the DTI metrics, in accordance with changes in the gut microbiota composition. At the bacterial phylum level, we showed that the abundances of Actinobacteria, Verrucomicrobia, and Tenericutes were significantly correlated with the DTI metrics FA, AD, and RD, respectively. Finally, we revealed that the expression of myelin-associated proteins, myelin bassic protein (MBP) and proteolipid protein (PLP) was increased after the treatment. Overall, we showed a strong correlation between structural connectivity alterations and social behavioral deficits, as well as the diet-dependent changes in gut microbiota composition.

Regulation of intestinal microflora and metabolites of Penthorum chinense Pursh on alcoholic liver disease

Introduction: Alcoholic liver disease (ALD) was the second leading cause of liver injury. Penthorum chinense Pursh (GHC) is an important Miao ethnic drug of traditional Chinese medicine for the treatment of liver disease, but the pathogenesis is not clear. Aim of the study: To analysis the intestinal microflora and metabolic pathway of GHC on ALD mice. Methods: An HPLC-QTOF-MS method was used to identified the components from GHC extract, firstly. 60 mice were divided into six groups including blank group, model group, positive group and GHC groups (0.29, 0.87 and 2.61 g/kg). ALD mice was treated with GHC for 12 days. ALT, AST, TC and TG in serum were determined, liver index and pathological analysis were achieved. 16S rRNA gene sequencing was used to detect the intestinal microbial diversity. Finally, UPLC-QTOF-MS was used to analysis the metabolic pathways. Results: 38 ingredients were identified in GHC extract. Compared with the model group, liver index of the positive group and GHC (2.61 g/kg) group was significantly reduced. Compared with the model group, contents of ALT, AST, TC and TG of GHC groups reduced in a dose-dependent manner. Intestinal microbial diversity analysis indicated that Chao1, Observed species, Pielou_e, and Shannon indexes in GHC group (2.61 g/kg) were lower than those in model group. Principal coordinate analysis indicated that the intestinal microbial composition between blank group and model group, the model group and GHC (2.61 g/kg) group changed significantly. Compared with the model group, proportion of Firmicutes decreased, and the proportion of Bacteroidetes increased significantly in GHC group, which were 50.84% and 40.15%. The more prominent bacteria in the GHC group were odoribacteraceae, turicibacter, deferribacteraceae, and the intestinal beneficial symbiotic bacteria mucispirillum. Metabolic analysis indicated that, compared with blank group, 90 metabolites in model group changed significantly, and 68 metabolites were significantly callback in GHC group. Discussion: GHC has a therapeutic effect on ALD by regulating intestinal flora imbalance and metabolic pathways including Glycine, serine and threonine metabolism, Glutathione metabolism, Arginine and proline metabolism, Alanine, aspartate and glutamate metabolism, Butanoate metabolism and primary bile acid biosynthesis.

Antioxidant, anti-inflammatory and epigenetic potential of curcumin in Alzheimer's disease

Alzheimer's disease (AD) constitutes a multifactorial neurodegenerative pathology characterized by cognitive deterioration, personality alterations, and behavioral shifts. The ongoing brain impairment process poses significant challenges for therapeutic interventions due to activating multiple neurotoxic pathways. Current pharmacological interventions have shown limited efficacy and are associated with significant side effects. Approaches focusing on the early interference with disease pathways, before activation of broad neurotoxic processes, could be promising to slow down symptomatic progression of the disease. Curcumin-an integral component of traditional medicine in numerous cultures worldwide-has garnered interest as a promising AD treatment. Current research indicates that curcumin may exhibit therapeutic potential in neurodegenerative pathologies, attributed to its potent anti-inflammatory and antioxidant properties. Additionally, curcumin and its derivatives have demonstrated an ability to modulate cellular pathways via epigenetic mechanisms. This article aims to raise awareness of the neuroprotective properties of curcuminoids that could provide therapeutic benefits in AD. The paper provides a comprehensive overview of the neuroprotective efficacy of curcumin against signaling pathways that could be involved in AD and summarizes recent evidence of the biological efficiency of curcumins in vivo.

Taming microglia: the promise of engineered microglia in treating neurological diseases

Microglia, the CNS-resident immune cells, are implicated in many neurological diseases. Nearly one in six of the world's population suffers from neurological disorders, encompassing neurodegenerative and neuroautoimmune diseases, most with dysregulated neuroinflammation involved. Activated microglia become phagocytotic and secret various immune molecules, which are mediators of the brain immune microenvironment. Given their ability to penetrate through the blood-brain barrier in the neuroinflammatory context and their close interaction with neurons and other glial cells, microglia are potential therapeutic delivery vehicles and modulators of neuronal activity. Re-engineering microglia to treat neurological diseases is, thus, increasingly gaining attention. By altering gene expression, re-programmed microglia can be utilized to deliver therapeutics to targeted sites and control neuroinflammation in various neuroinflammatory diseases. This review addresses the current development in microglial engineering, including genetic targeting and therapeutic modulation. Furthermore, we discuss limitations to the genetic engineering techniques and models used to test the functionality of re-engineered microglia, including cell culture and animal models. Finally, we will discuss future directions for the application of engineered microglia in treating neurological diseases.

Targeted therapies of curcumin focus on its therapeutic benefits in cancers and human health: Molecular signaling pathway-based approaches and future perspectives

The curry powder spices turmeric (Curcuma longa L.), which contains curcumin (diferuloylmethane), an orange-yellow chemical. Polyphenols are the most commonly used sources of curcumin. It combats oxidative stress and inflammation in diseases, such as hyperlipidemia, metabolic syndrome, arthritis, and depression. Most of these benefits are due to their anti-inflammatory and antioxidant properties. Curcumin consumption leads to decreased bioavailability, resulting in limited absorption, quick metabolism, and quick excretion, which hinders health improvement. Numerous factors can increase its bioavailability. Piperine enhances bioavailability when combined with curcumin in a complex. When combined with other enhancing agents, curcumin has a wide spectrum of health benefits. This review evaluates the therapeutic potential of curcumin with a specific emphasis on its approach based on molecular signaling pathways. This study investigated its influence on the progression of cancer, inflammation, and many health-related mechanisms, such as cell proliferation, apoptosis, and metastasis. Curcumin has a significant potential for the prevention and treatment of various diseases. Curcumin modulates several biochemical pathways and targets involved in cancer growth. Despite its limited tissue accumulation and bioavailability when administered orally, curcumin has proven useful. This review provides an in-depth analysis of curcumin's therapeutic applications, its molecular signaling pathway-based approach, and its potential for precision medicine in cancer and human health.

Impact of Baizhu, Daqingye, and Hehuanhua extracts on the human gut microbiome

Introduction

In traditional Chinese medicine, the rhizome of Atractylodes macrocephala (Baizhu), the leaves of Isatis indigotica (Daqingye), and the flowers of Albizia julibrissin (Hehuanhua) have been used to treat gastrointestinal illnesses, epidemics, and mental health issues. Modern researchers are now exploring the underlying mechanisms responsible for their efficacy. Previous studies often focused on the impact of purified chemicals or mixed extracts from these plants on cells in tissue culture or in rodent models.

Methods

As modulation of the human gut microbiome has been linked to host health status both within the gastrointestinal tract and in distant tissues, the effects of lipid-free ethanol extracts of Baizhu, Daqingye, and Hehuanhua on the human adult gut microbiome were assessed using Systemic Intestinal Fermentation Research (SIFR®) technology (n=6).

Results and discussion

Baizhu and Daqingye extracts similarly impacted microbial community structure and function, with the extent of effects being more pronounced for Baizhu. These effects included decreases in the Bacteroidetes phylum and increases in health-related Bifidobacterium spp. and short chain fatty acids which may contribute to Baizhu's efficacy against gastrointestinal ailments. The changes upon Hehuanhua treatment were larger and included increases in multiple bacterial species, including Agathobaculum butyriciproducens, Adlercreutzia equolifaciens, and Gordonibacter pamelaeae, known to produce secondary metabolites beneficial to mental health. In addition, many of the changes induced by Hehuanhua correlated with a rise in Enterobacteriaceae spp., which may make the tested dose of this herb contraindicated for some individuals. Overall, there is some evidence to suggest that the palliative effect of these herbs may be mediated, in part, by their impact on the gut microbiome, but more research is needed to elucidate the exact mechanisms.

Curcumin enhances elvitegravir concentration and alleviates oxidative stress and inflammatory response

In this study, we investigated the potential of using curcumin (CUR) as an adjuvant to enhance the delivery of antiretroviral drug elvitegravir (EVG) across the BBB, and alleviate oxidative stress and inflammatory response, which are the major hallmark of HIV neuropathogenesis. In a mouse model, we compared the biodistribution of EVG alone and in combination with CUR using intraperitoneal (IP) and intranasal (IN) routes. IN administration showed a significantly higher accumulation of EVG in the brain, while both IP and IN routes led to increased EVG levels in the lungs and liver. The addition of CUR further enhanced EVG brain delivery, especially when administered via the IN route. The expression of neural marker proteins, synaptophysin, L1CAM, NeuN, and GFAP was not significantly altered by EVG or CUR alone or their combination, indicating preserved neural homeostasis. After establishing improved brain concentration and safety of CUR-adjuvanted EVG in mice in acute treatment, we studied the effect of this treatment in HIV-infected U1 macrophages. In U1 macrophages, we also observed that the addition of CUR enhanced the intracellular concentration of EVG. The total area under the curve (AUCtot) for EVG was significantly higher in the presence of CUR. We also evaluated the effects of CUR on oxidative stress and antioxidant capacity in EVG-treated U1 macrophages. CUR reduced oxidative stress, as evidenced by decreased reactive oxygen species (ROS) levels and elevated antioxidant enzyme expression. Furthermore, the combination of CUR and EVG exhibited a significant reduction in proinflammatory cytokines (TNFα, IL-1β, IL-18) and chemokines (RANTES, MCP-1) in U1 macrophages. Additionally, western blot analysis confirmed the decreased expression of IL-1β and TNF-α in EVG + CUR-treated cells. These findings suggest the potential of CUR to enhance EVG permeability to the brain and subsequent efficacy of EVG, including HIV neuropathogenesis.

Brain modulation by the gut microbiota: From disease to therapy

BACKGROUND

The gut microbiota (GM) and brain are strongly associated, which significantly affects neuronal development and disorders. GM-derived metabolites modulate neuronal function and influence many cascades in age-related neurodegenerative disorders (NDDs). Because of the dual role of GM in neuroprotection and neurodegeneration, understanding the balance between beneficial and harmful bacteria is crucial for applying this approach to clinical therapies.

AIM OF THE REVIEW

This review briefly discusses the role of the gut-brain relationship in promoting brain and cognitive function. Although a healthy gut environment is helpful for brain function, gut dysbiosis can disrupt the brain's environment and create a vicious cycle of degenerative cascades. The ways in which the GM population can affect brain function and the development of neurodegeneration are also discussed. In the treatment and management of NDDs, the beneficial effects of methods targeting GM populations and their derivatives, including probiotics, prebiotics, and fecal microbial transplantation (FMT) are also highlighted.

KEY SCIENTIFIC CONCEPT OF THE REVIEW

In this review, we aimed to provide a deeper understanding of the mechanisms of the gut microbe-brain relationship and their twin roles in neurodegeneration progression and therapeutic applications. Here, we attempted to highlight the different pathways connecting the brain and gut, together with the role of GM in neuroprotection and neuronal development. Furthermore, potential roles of GM metabolites in the pathogenesis of brain disorders and in strategies for its treatment are also investigated. By analyzing existing in vitro, in vivo and clinical studies, this review attempts to identify new and promising therapeutic strategies for central nervous system (CNS) disorders. As the connection between the gut microbe-brain relationship and responses to NDD treatments is less studied, this review will provide new insights into the global mechanisms of GM modulation in disease progression, and identify potential future perspectives for developing new therapies to treat NDDs.

Molecular Docking, Pharmacokinetic and Molecular Simulation Analysis of Novel Mono-Carbonyl Curcumin Analogs as L858R/T790M/C797S Mutant EGFR Inhibitors

INTRODUCTION

Curcumin, an anticancer natural compound with multiple pharmacological activities, has a weak pharmacokinetic and instability due to diketone moiety. Curcumin's stability challenges can be overcome by removing the diketone moiety and shortening the 7-carbon chain, resulting in mono-carbonyl analogs. Cancer proliferation is caused by the activation of Epidermal Growth Factor (EGFR) pathways. Current available EGFR inhibitors have an issue of resistance.

AIM

Thus, we aimed to design new mono-carbonyl curcumin derivatives and analyse their drug likeness properties. Further, to investigate them on three distinct crystal structures, namely two wild-type and L858R/T790M/C797S mutant generations for EGFR inhibitory activity.

METHOD

Ten New Molecular Entities (NME's) were designed using literature survey. These molecules were subjected to comparative molecular docking, on the EGFR crystal structures viz. wild-type (PDB: 1M17 and 4I23) and L858R/T790M/C797S mutant (PDB: 6LUD) using Schrodinger software. The molecules were also tested for Absorption, Distribution, Metabolism, Excretion and Toxicity (ADMET) properties. The docked complex of the hit molecule was studied for molecular simulation.

RESULT AND DISCUSSION

In molecular docking studies, NMEs 1, 2, and 3 were found to have good binding affinity with 1st , 2nd , and 3rd generation EGFR crystal structures and a greater dock score than standard curcumin. All molecules have shown a good ADMET profile. Since L858R/T790M/C797S is currently being explored more, we decided to take the best molecule, NME 3, for molecular dynamics with 6LUD, and the results were compared with those of the co-crystallized ligand S4 (Osimertinib). It was found that the Relative mean square standard deviation (RMSD) (1.8 Å), Relative mean standard Fluctuation (RMSF) (1.45 Å) and radius of gyration (4.87 Å) values of NME 3 were much lower than those of reference S4. All these confirm that our designed NME 3 is more stable than reference S4.

CONCLUSION

NME 1 and NME 2 have shown better binding against wild type of EGFR. NME 3 have shown comparable binding and more stability as compared to Osimertinib against L858R/T790M/C797S mutated protein structure. The hit compound can be further explored for its Molecular mechanics with generalised Born and surface area solvation (MM-GBSA) and discrete Fourier transform (DFT) studies to find out the energy and atomic level study. In the future, this molecule could be taken for wet lab studies and can be tested for mutated EGFR inhibitory activity.

Antiplatelet drugs: Potential therapeutic options for the management of neurodegenerative diseases

The blood platelet plays an important role but often remains under-recognized in several vascular complications and associated diseases. Surprisingly, platelet hyperactivity and hyperaggregability have often been considered the critical risk factors for developing vascular dysfunctions in several neurodegenerative diseases (NDDs) like Alzheimer's disease, Parkinson's disease, Huntington's disease, and multiple sclerosis. In addition, platelet structural and functional impairments promote prothrombotic and proinflammatory environment that can aggravate the progression of several NDDs. These findings provide the rationale for using antiplatelet agents not only to prevent morbidity but also to reduce mortality caused by NDDs. Therefore, we thoroughly review the evidence supporting the potential pleiotropic effects of several novel classes of synthetic antiplatelet drugs, that is, cyclooxygenase inhibitors, adenosine diphosphate receptor antagonists, protease-activated receptor blockers, and glycoprotein IIb/IIIa receptor inhibitors in NDDs. Apart from this, the review also emphasizes the recent developments of selected natural antiplatelet phytochemicals belonging to key classes of plant-based bioactive compounds, including polyphenols, alkaloids, terpenoids, and flavonoids as potential therapeutic candidates in NDDs. We believe that the broad analysis of contemporary strategies and specific approaches for plausible therapeutic treatment for NDDs presented in this review could be helpful for further successful research in this area.

The Effect of Curcumin on the Gut-Brain Axis: Therapeutic Implications

The gut-brain axis describes the bidirectional communication between the gut, the enteric nervous system, and the central nervous system. The gut-brain axis has attracted increasing attention owing to its regulatory effect on dysbiosis and a wide range of related diseases. Several types of nutrients, such as curcumin, have been proposed as regulators of the dysbiotic state, and preclinical experiments have suggested that curcumin is not only beneficial but also safe. This review focuses on the interplay between curcumin and the gut microbiota. Moreover, it provides a comprehensive review of the crosstalk between the gut-brain axis and disease, whilst also discussing curcumin-mediated gut-brain axis-dependent and -independent signaling about modulation of gut microbiota dysbiosis. This will help to define the utility of curcumin as a novel therapeutic agent to regulate intestinal microflora dysbiosis.

Pharmacological intervention of curcumin via the NLRP3 inflammasome in ischemic stroke

Ischemic-induced neuronal injury arises due to low oxygen/nutrient levels and an inflammatory response that exacerbates neuronal loss. NOD-like receptor family pyrin domain-containing 3 (NLRP3) is an important regulator of inflammation after ischemic stroke, with its inhibition being involved in nerve regeneration. Curcumin, a main active ingredient in Chinese herbs, plays a positive role in neuronal repair and neuroprotection by regulating the NLRP3 signaling pathway. Nevertheless, the signaling mechanisms relating to how curcumin regulates NLRP3 inflammasome in inflammation and neural restoration following ischemic stroke are unknown. In this report, we summarize the main biological functions of the NLRP3 inflammasome along with the neuroprotective effects and underlying mechanisms of curcumin via impairment of the NLRP3 pathway in ischemic brain injury. We also discuss the role of medicinal interventions that target the NLRP3 and potential pathways, as well as possible directions for curcumin therapy to penetrate the blood-brain barrier (BBB) and hinder inflammation in ischemic stroke. This report conclusively demonstrates that curcumin has neuroprotective properties that inhibit inflammation and prevent nerve cell loss, thereby delaying the progression of ischemic brain damage.

Managing ferroptosis-related diseases with indirect dietary modulators of ferroptosis

Ferroptosis is an iron-dependent form of programmed cell death driven by excessive oxidation of polyunsaturated phospholipids on cellular membranes. Accumulating evidence suggests that ferroptosis has been implicated in the pathological process of various diseases, such as cardiovascular diseases, neurological diseases, liver diseases, kidney injury, lung injury, diabetes, and cancer. Targeting ferroptosis is therefore considered to be a reasonable strategy to fight against ferroptosis-associated diseases. Many dietary bioactive agents have been identified to be able to either suppress or promote ferroptosis, indicating that ferroptosis-based intervention by dietary approach may be an effective strategy for preventing and treating diseases associated with ferroptosis dysregulation. In this review, we summarize the present understanding of the functional role of ferroptosis in the pathogenesis of aforementioned diseases with an emphasis on the evidence of managing ferroptosis-related diseases with indirect dietary modulators of ferroptosis and propose issues that need to be addressed to promote practical application of dietary approach targeting ferroptosis.

Lactoferrin: neuroprotection against Parkinson's disease and secondary molecule for potential treatment

Parkinson's disease (PD) is the second-most common neurodegenerative disease and is largely caused by the death of dopaminergic (DA) cells. Dopamine loss occurs in the substantia nigra pars compacta and leads to dysfunctions in motor functions. Death of DA cells can occur with oxidative stress and dysfunction of glial cells caused by Parkinson-related gene mutations. Lactoferrin (Lf) is a multifunctional glycoprotein that is usually known for its presence in milk, but recent research shows that Lf is also found in the brain regions. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a known mitochondrial toxin that disturbs the mitochondrial electron transport chain (ETC) system and increases the rate of reactive oxygen species. Lf's high affinity for metals decreases the required iron for the Fenton reaction, reduces the oxidative damage to DA cells caused by MPTP, and increases their surveillance rate. Several studies also investigated Lf's effect on neurons that are treated with MPTP. The results pointed out that Lf's protective effect can also be observed without the presence of oxidative stress; thus, several potential mechanisms are currently being researched, starting with a potential HSPG-Lf interaction in the cellular membrane of DA cells. The presence of Lf activity in the brain region also showed that lactoferrin initiates receptor-mediated transcytosis in the blood-brain barrier (BBB) with the existence of lactoferrin receptors in the endothelial cells. The existence of Lf receptors both in endothelial cells and DA cells created the idea of using Lf as a secondary molecule in the transport of therapeutic agents across the BBB, especially in nanoparticle development.

Management of dog sperm parameters and gut microbiota composition with Lactobacillus rhamnosus supplementation

The effects of probiotics supplementation on the reproductive function have been evaluated in many species, but no study has evaluated the changes in the gut microbiome along with the sperm quality changes simultaneously. This study evaluated the effects of dietary supplementation with probiotics on the gut microbiome, sperm quality and gene expression, along with possible correlations between these parameters in dogs. The dogs were supplemented with Lactobacillus rhamnosus for six weeks, and fecal and semen samples were collected at 0, 3, and 6 weeks. Fecal samples were assessed using 16S Metagenomic Sequencing for gut microbiome analysis; and semen samples were analyzed using computer-assisted sperm analysis, DNA and acrosome integrity assessment, viability and morphology assessment, and real-time PCR. The analyses suggested that probiotic supplementation improved kinematic parameters, viability, DNA and acrosome integrity, and morphology of sperms. The mRNA levels of genes associated with fertility, DNA repair and integrity, and antioxidation were also upregulated. The sperm parameters were positively correlated with the relative abundance of Actinobacteria, Allobaculum, Phascolarctobacterium and Catenibacterium, and negatively correlated with Faecalibacterium and Streptococcus. Taken together, the sperm quality enhancement through the gut-testis axis may be due to a change in the gut microorganisms populations.

Phytopharmaceuticals and Herbal Approaches to Target Neurodegenerative Disorders

Neurodegeneration is characterized as the continuous functional and structural loss of neurons, resulting in various clinical and pathological manifestations and loss of functional anatomy. Medicinal plants have been oppressed from ancient years and are highly considered throughout the world as a rich source of therapeutic means for the prevention, treatment of various ailments. Plant-derived medicinal products are becoming popular in India and other nations. Further herbal therapies shows good impact on chronic long term illnesses including degenerative conditions of neurons and brain. The use of herbal medicines continues to expand rapidly across the world. The active phytochemical constituents of individual plants are sometimes insufficient to achieve the desirable therapeutic effects. Combining the multiple herbs in a particular ratio (polyherbalism) will give a better therapeutic effect and reduce toxicity. Herbal-based nanosystems are also being studied as a way to enhance the delivery and bioavailability of phytochemical compounds for the treatment of neurodegenerative diseases. This review mainly focuses on the importance of the herbal medicines, polyherbalism and herbal-based nanosystems and its clinical significance for neurodegenerative diseases.

Applications of Curcumin and Its Nanoforms in the Treatment of Cancer

Due to the diverse medicinal and pharmacokinetic properties of turmeric, it is well-known in the therapeutic, pharmaceutic, nutraceutical, cosmetic, and dietary industries. It gained importance due to its multitude of properties, such as wound-healing, anti-inflammatory, anti-oxidant, anti-microbial, cytoprotective, anti-aging, anti-cancer, and immunomodulatory effects. Even though the natural healing effect of turmeric has been known to Indians as early as 2500 BCE, the global demand for turmeric has increased only recently. A major reason for the beneficiary activities of turmeric is the presence of the yellow-colored polyphenolic compound called curcumin. Many studies have been carried out on the various properties of curcumin and its derivatives. Despite its low bioavailability, curcumin has been effectively used for the treatment of many diseases, such as cardiovascular and neurological diseases, diabetes, arthritis, and cancer. The advent of nanobiotechnology has further opened wide opportunities to explore and expand the use of curcumin in the medical field. Nanoformulations using curcumin and its derivatives helped to design new treatment modalities, specifically in cancer, because of the better bioavailability and solubility of nanocurcumin when compared to natural curcumin. This review deals with the various applications of curcumin nanoparticles in cancer therapy and broadly tries to understand how it affect the immunological status of the cancer cell.

Biodistribution and racemization of gut-absorbed L/D-alanine in germ-free mice

Microbiome-derived metabolites are important for the microbiome-gut-brain axis and the discovery of new disease treatments. D-Alanine (D-Ala) is found in many animals as a potential co-agonist of the N-methyl-D-aspartate receptors (NMDAR), receptors widely used in the nervous and endocrine systems. The gut microbiome, diet and putative endogenous synthesis are the potential sources of D-Ala in animals, although there is no direct evidence to show the distribution and racemization of gut-absorbed L-/D-Ala with regards to host-microbe interactions in mammals. In this work, we utilized germ-free mice to control the interference from microbiota and isotopically labeled L-/D-Ala to track their biodistribution and racemization in vivo. Results showed time-dependent biodistribution of gut-absorbed D-Ala, particularly accumulation of gut-absorbed D-Ala in pancreatic tissues, brain, and pituitary. No endogenous synthesis of D-Ala via racemization was observed in germ-free mice. The sources of D-Ala in mice were revealed as microbiota and diet, but not endogenous racemization. This work indicates the importance of further investigating the in vivo biological functions of gut-microbiome derived D-Ala, particularly on NMDAR-related activities, for D-Ala as a potential signaling molecules in the microbiome-gut-brain axis.

Curcumin enhances elvitegravir concentration and alleviates oxidative stress and inflammatory response

In this study, we investigated the potential of using curcumin (CUR) as an adjuvant to enhance the delivery of antiretroviral drug elvitegravir (EVG) across the BBB, and alleviate oxidative stress and inflammatory response, which are the major hallmark of HIV neuropathogenesis. In a mouse model, we compared the biodistribution of EVG alone and in combination with CUR using intraperitoneal (IP) and intranasal (IN) routes. IN administration showed a significantly higher accumulation of EVG in the brain, while both IP and IN routes led to increased EVG levels in the lungs and liver. The addition of CUR further enhanced EVG brain delivery, especially when administered via the IN route. The expression of neural marker proteins, synaptophysin, L1CAM, NeuN, and GFAP was not significantly altered by EVG or CUR alone or their combination, indicating preserved neural homeostasis. After establishing improved brain concentration and safety of CUR-adjuvanted EVG in mice in acute treatment, we studied the effect of this treatment in HIV-infected U1 macrophages. In U1 macrophages, we also observed that the addition of CUR enhanced the intracellular concentration of EVG. The total area under the curve (AUCtot) for EVG was significantly higher in the presence of CUR. We also evaluated the effects of CUR on oxidative stress and antioxidant capacity in EVG-treated U1 macrophages. CUR reduced oxidative stress, as evidenced by decreased reactive oxygen species (ROS) levels and elevated antioxidant enzyme expression. Furthermore, the combination of CUR and EVG exhibited a significant reduction in proinflammatory cytokines (TNFα, IL-1β, IL-18) and chemokines (RANTES, MCP-1) in U1 macrophages. Additionally, western blot analysis confirmed the decreased expression of IL-1β and TNF-α in EVG + CUR-treated cells. These findings suggest the potential of CUR to enhance EVG permeability to the brain and subsequent efficacy of EVG, including HIV neuropathogenesis.

An Overview of the Enhanced Effects of Curcumin and Chemotherapeutic Agents in Combined Cancer Treatments

Due to the progressive ageing of the human population, the number of cancer cases is increasing. For this reason, there is an urgent need for new treatments that can prolong the lives of cancer patients or ensure them a good quality of life. Although significant progress has been made in the treatment of cancer in recent years and the survival rate of patients is increasing, limitations in the use of conventional therapies include the frequent occurrence of side effects and the development of resistance to chemotherapeutic agents. These limitations are prompting researchers to investigate whether combining natural agents with conventional drugs could have a positive therapeutic effect in cancer treatment. Several natural bioactive compounds, especially polyphenols, have been shown to be effective against cancer progression and do not exert toxic effects on healthy tissues. Many studies have investigated the possibility of combining polyphenols with conventional drugs as a novel anticancer strategy. Indeed, this combination often has synergistic benefits that increase drug efficacy and reduce adverse side effects. In this review, we provide an overview of the studies describing the synergistic effects of curcumin, a polyphenol that has been shown to have extensive cytotoxic functions against cancer cells, including combined treatment. In particular, we have described the results of recent preclinical and clinical studies exploring the pleiotropic effects of curcumin in combination with standard drugs and the potential to consider it as a promising new tool for cancer therapy.

The improvement of intestinal dysbiosis and hepatic metabolic dysfunction in dextran sulfate sodium-induced colitis mice: effects of curcumin

BACKGROUND AND AIM

Curcumin may have promising application in the prevention and amelioration of inflammatory bowel disease (IBD). However, the underlying mechanisms underpinning the ability of curcumin to interact with the gut and liver in IBD remains to be defined, which is the exploration aim of this study.

METHODS

Mice with dextran sulfate sodium salt (DSS)-induced acute colitis were treated either with 100 mg/kg of curcumin or phosphate buffer saline (PBS). Hematoxylin-eosin (HE) staining, 16S rDNA Miseq sequencing, proton nuclear magnetic resonance (1 H NMR) spectroscopy, and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were applied for analysis. Spearman's correlation coefficient (SCC) was utilized to assess the correlation between the modification of intestinal bacteria and hepatic metabolite parameters.

RESULTS

Curcumin supplementation not only prevented further loss of body weight and colon length in IBD mice but also improved diseases activity index (DAI), colonic mucosal injury, and inflammatory infiltration. Meanwhile, curcumin restored the composition of the gut microbiota, significantly increased Akkermansia, Muribaculaceae_unclassified, and Muribaculum, and significantly elevated the concentration of propionate, butyrate, glycine, tryptophan, and betaine in the intestine. For hepatic metabolic disturbances, curcumin intervention altered 14 metabolites, including anthranilic acid and 8-amino-7-oxononanoate while enriching pathways related to the metabolism of bile acids, glucagon, amino acids, biotin, and butanoate. Furthermore, SCC analysis revealed a potential correlation between the upregulation of intestinal probiotics and alterations in liver metabolites.

CONCLUSION

The therapeutic mechanism of curcumin against IBD mice occurs by improving intestinal dysbiosis and liver metabolism disorders, thus contributing to the stabilization of the gut-liver axis.

Polysaccharides-based nanocarriers enhance the anti-inflammatory effect of curcumin

Curcumin (CUR) has been discovered to have many biological activities, including anti-inflammatory, anti-cancer, anti-oxygenation, anti-human immunodeficiency virus, anti-microbial and exhibits a good effect on the prevention and treatment of many diseases. However, the limited properties of CUR, including the poor solubility, bioavailability and instability caused by enzymes, light, metal irons, and oxygen, have compelled researchers to turn their attention to drug carrier application to overcome these drawbacks. Encapsulation may provide potential protective effects to the embedding materials and/or have a synergistic effect with them. Therefore, nanocarriers, especially polysaccharides-based nanocarriers, have been developed in many studies to enhance the anti-inflammatory capacity of CUR. Consequently, it's critical to review current advancements in the encapsulation of CUR using polysaccharides-based nanocarriers, as well as further study the potential mechanisms of action where polysaccharides-based CUR nanoparticles (the complex nanoparticles/Nano CUR-delivery systems) exhibit their anti-inflammatory effects. This work suggests that polysaccharides-based nanocarriers will be a thriving field in the treatment of inflammation and inflammation-related diseases.

PET Imaging and Neurohistochemistry Reveal that Curcumin Attenuates Brain Hypometabolism and Hippocampal Damage Induced by Status Epilepticus in Rats

Numerous preclinical studies provide evidence that curcumin, a polyphenolic phytochemical extracted from Curcuma longa (turmeric) has neuroprotective, anti-inflammatory and antioxidant properties against various neurological disorders. Curcumin neuroprotective effects have been reported in different animal models of epilepsy, but its potential effect attenuating brain glucose hypometabolism, considered as an early marker of epileptogenesis that occurs during the silent period following status epilepticus (SE), still has not been addressed. To this end, we used the lithium-pilocarpine rat model to induce SE. Curcumin was administered orally (300 mg/kg/day, for 17 days). Brain glucose metabolism was evaluated in vivo by 2-deoxy-2-[¹⁸F]Fluoro-D-Glucose ([¹⁸F]FDG) positron emission tomography (PET). In addition, hippocampal integrity, neurodegeneration, microglia-mediated neuroinflammation, and reactive astrogliosis were evaluated as markers of brain damage. SE resulted in brain glucose hypometabolism accompanied by body weight (BW) loss, hippocampal neuronal damage, and neuroinflammation. Curcumin did not reduce the latency time to the SE onset, nor the mortality rate associated with SE. Nevertheless, it reduced the number of seizures, and in the surviving rats, curcumin protected BW and attenuated the short-term glucose brain hypometabolism as well as the signs of neuronal damage and neuroinflammation induced by the SE. Overall, our results support the potential adaptogen-like effects of curcumin attenuating key features of SE-induced brain damage.

Curcumin Ameliorates Neurobehavioral Deficits in Ambient Dusty Particulate Matter-Exposure Rats: The Role of Oxidative Stress

It has been consistently found that exposure to ambient air pollution, such as particulate matter (PM), results in cognitive impairments and mental disorders. This study aimed to investigate the possible neuroprotective effects of curcumin, a polyphenol compound, on the neurobehavioral deficits and to identify the role of oxidative stress in dusty PM exposure rats. Rats received curcumin (50 mg/kg, daily, gavage, 2 weeks) 30 min before placing animals in a clean air chamber (≤ 150 µg/m³, 60 min daily, 2 weeks) or ambient dusty PM chamber (2000-8000 µg/m³, 60 min daily, 2 weeks). Subsequently, the cognitive and non-cognitive functions of the animals were evaluated using standard behavioral tests. Moreover, blood-brain barrier (BBB) permeability, brain water content (BWC), oxidative-antioxidative status, and histological changes were determined in the cerebral cortex and hippocampal areas of the rats. Our results showed that curcumin administration in dusty PM exposure rats attenuates memory impairment, decreases anxiety-/depression-like behaviors, and improves locomotor/exploratory activities. These findings were accompanied by reduced BBB permeability and BWC, decreasing oxidative stress, and lessening neuronal loss in the cerebral cortex and different hippocampal areas. The results of this study suggest that curcumin's antioxidant properties may contribute to its efficacy in improving neurobehavioral deficits and preventing neuronal loss associated with dusty PM exposure.

Curcumin-resveratrol nano-formulation counteracting hyperammonemia in rats

Malnutrition and low dietary protein intake could be risk factors for developing peripheral and central hyperammonemia, especially in pediatrics. Both curcumin and resveratrol proved to be effective against several hepatic and cerebral injuries. They were reported to be beneficial in lowering circulating ammonia levels, yet both are known for their low bioavailability. The use of pharmaceutical nano-formulations as delivery systems for these two nutraceuticals could solve the aforementioned problem. Hence, the present study aimed to investigate the valuable outcome of using a combination of curcumin and resveratrol in a nanoemulsion formulation, to counteract protein-deficient diet (PDD)-induced hyperammonemia and the consequent complications in male albino rats. Results revealed that using a nanoemulsion containing both curcumin and resveratrol at a dose of (5 + 5 mg/kg) effectively reduced hepatic and brain ammonia levels, serum ALT and AST levels, hepatic and brain nitric oxide levels, oxidative DNA damage as well as disrupted cellular energy performance. In addition, there was a substantial increase in brain levels of monoamines, and a decrease in glutamate content. Therefore, it can be concluded that the use of combined curcumin and resveratrol nanoemulsion is an effective means of ameliorating the hepatic and cerebral adverse effects resulting from PDD-induced hyperammonemia in rats.

Regional distributions of curcumin and tetrahydrocurcumin in the liver and small intestine of rats when orally co-administered with quercetin and paeoniflorin

Curcumin (CUR), derived from the dietary spice turmeric, is a polyphenolic compound with various biological and pharmacological activities. Tetrahydrocurcumin (THC) is one of the major reductive metabolites of curcumin. A pharmacokinetic study using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) for the simultaneous determination of curcumin, THC, quercetin (QR), and paeoniflorin (PF) in rat plasma had been performed. In this study, the regional distributions of curcumin and tetrahydrocurcumin in the liver and the three segments of small intestine (duodenum, jejunum, and ileum) of rats when orally co-administered with quercetin and paeoniflorin were carried out. Drug concentrations were determined using UHPLC-MS/MS. The results showed that curcumin was well distributed in the small intestine, while the distributions of tetrahydrocurcumin in the liver, duodenum, jejunum were similar, but much more abundant in the ileum. When orally co-administered with quercetin and paeoniflorin, the tissue to plasma concentration ratios (K_p values) of curcumin in the three segments of the small intestine were increased, indicating that the presence of quercetin and paeoniflorin increases the distribution of curcumin in these regions. Moreover, the half-life (t_1/2 ) of THC in the liver was significantly prolonged, and the K_p value of THC in the liver was increased and the K_p values in the small intestine were decreased, suggesting that the combination of quercetin and paeoniflorin might suppress the metabolism of curcumin in the small intestine. In brief, the combination had an effect on the distributions of curcumin and tetrahydrocurcumin in the liver and small intestine of rats.

Impacts of turmeric and its principal bioactive curcumin on human health: Pharmaceutical, medicinal, and food applications: A comprehensive review

The yellow polyphenolic pigment known as curcumin, originating from the rhizome of the turmeric plant Curcuma longa L., has been utilized for ages in ancient medicine, as well as in cooking and food coloring. Recently, the biological activities of turmeric and curcumin have been thoroughly investigated. The studies mainly focused on their antioxidant, antitumor, anti-inflammatory, neuroprotective, hepatoprotective, and cardioprotective impacts. This review seeks to provide an in-depth, detailed discussion of curcumin usage within the food processing industries and its effect on health support and disease prevention. Curcumin's bioavailability, bio-efficacy, and bio-safety characteristics, as well as its side effects and quality standards, are also discussed. Finally, curcumin's multifaceted uses, food appeal enhancement, agro-industrial techniques counteracting its instability and low bioavailability, nanotechnology and focused drug delivery systems to increase its bioavailability, and prospective clinical use tactics are all discussed.

Poly(pro-curcumin) Materials Exhibit Dual Release Rates and Prolonged Antioxidant Activity as Thin Films and Self-Assembled Particles

Curcumin is a natural polyphenol that exhibits remarkable antioxidant and anti-inflammatory activities; however, its clinical application is limited in part by its physiological instability. Here, we report the synthesis of curcumin-derived polyesters that release curcumin upon hydrolytic degradation to improve curcumin stability and solubility in physiological conditions. Curcumin was incorporated in the polymer backbone by a one-pot condensation polymerization in the presence of sebacoyl chloride and polyethylene glycol (PEG, M_n = 1 kDa). The thermal and mechanical properties, surface wettability, self-assembly behavior, and drug-release kinetics all depend sensitively on the mole percentage of curcumin incorporated in these statistical copolymers. Curcumin release was triggered by the hydrolysis of phenolic esters on the polymer backbone, which was confirmed using a PEGylated curcumin model compound, which represented a putative repeating unit within the polymer. The release rate of curcumin was controlled by the hydrophilicity of the polymers. Burst release (2 days) and extended release (>8 weeks) can be achieved from the same polymer depending on curcumin content in the copolymer. The materials can quench free radicals for at least 8 weeks and protect primary neurons from oxidative stress in vitro. Further, these copolymer materials could be processed into both thin films and self-assembled particles, depending on the solvent-based casting conditions. Finally, we envision that these materials may have potential for neural tissue engineering application, where antioxidant release can mitigate oxidative stress and the inflammatory response following neural injury.

Anti-aging effects of dietary phytochemicals: From Caenorhabditis elegans, Drosophila melanogaster, rodents to clinical studies

Anti-aging research has become critical since the elderly population is increasing dramatically in this era. With the establishment of frailty phenotype and frailty index, the importance of anti-frailty research is concurrently enlightened. The application of natural phytochemicals against aging or frailty is always intriguing, and abundant related studies have been published. Various models are designed for biological research, and each model has its strength and weakness in deciphering the complex aging mechanisms. In this article, we attempt to show the potential of Caenorhabditis elegans in the study of phytochemicals' effects on anti-aging by comparing it to other animal models. In this review, the lifespan extension and anti-aging effects are demonstrated by various physical, cellular, or molecular biomarkers of dietary phytochemicals, including resveratrol, curcumin, urolithin A, sesamin, fisetin, quercetin, epigallocatechin-3-gallate, epicatechin, spermidine, sulforaphane, along with extracts of broccoli, cocoa, and blueberry. Meanwhile, the frequency of phytochemicals and models studied or presented in publications since 2010 were analyzed, and the most commonly mentioned animal models were rats, mice, and the nematode C. elegans. This up-to-date summary of the anti-aging effect of certain phytochemicals has demonstrated powerful potential for anti-aging or anti-frailty in the human population.

A Review: Exploring Synthetic Schemes and Structure-activity Relationship (SAR) Studies of Mono-carbonyl Curcumin Analogues for Cytotoxicity Inhibitory Anticancer Activity

INTRODUCTION

Cancer is the major cause of death globally. Cancer can be treated with naturally occurring Curcumin nuclei. Curcumin has a wide range of biological actions, including anti-inflammatory and anti-cancer properties. Even though it is an effective medicinal entity, it has some limitations such as instability at physiological pH and a weak pharmacokinetic profile due to the β-diketone moiety present in it. To overcome this drawback, research was carried out on monoketone moieties in curcumin, popularly known as mono-carbonyl curcumin.

OBJECTIVE

The present review focuses on different synthetic schemes and Mono-carbonyl curcumin derivative's Structure-Activity Relationship (SAR) as a cytotoxic inhibitory anticancer agent. The various synthetic schemes published by researchers were compiled.

METHODS

Findings of different researchers working on mono-carbonyl curcumin as an anticancer have been reviewed, analyzed and the outcomes were summarized.

RESULTS

The combination of all of these approaches serves as a one-stop solution for mono-carbonyl curcumin synthesis. The important groups on different positions of mono-carbonyl curcumin were discovered by a SAR study focused on cytotoxicity, which could be useful in the designing of its derivatives.

CONCLUSION

Based on our examination of the literature, we believe that this review will help researchers design and develop powerful mono-carbonyl curcumin derivatives that can be proven essential for anticancer activity.

Natural Phytochemicals for the Treatment of Major Depressive Disorder: A Mini-Review of Pre- and Clinical Studies

Major Depressive Disorder (MDD) is a common mental illness that causes significant disability and declining quality of life. An overlap of multiple factors can be involved in the pathophysiology of this mood disorder, including increased inflammation and oxidative stress, change in neurotransmitters, decreased brain-derived neurotrophic factor (BDNF), activation of the hypothalamicpituitary- adrenal (HPA) axis, and changes in the microbiota-gut-brain axis. Although the classic treatment for MDD is safe, it is far from ideal, with delay to start the best clinic, side effects, and a large number of non-responses or partial-responses. Therefore, other alternatives are being studied to improve depressive symptoms, and, among them, the role of phytochemicals in food stands out. This mini-review will discuss the main phytochemicals present in foods with clinical and preclinical studies showing benefits for MDD treatment. In addition, the main mechanisms of action that are being proposed for each of these compounds will be addressed.

Exploring the Neuroprotective Mechanism of Curcumin Inhibition of Intestinal Inflammation against Parkinson's Disease Based on the Gut-Brain Axis

Parkinson's disease (PD) is a chronic progressive neurodegenerative disease commonly seen in aged people, in which gastrointestinal dysfunction is the most common nonmotor symptom and the activation of the gut-brain axis by intestinal inflammation may contribute to the pathogenesis of PD. In a previous study, curcumin was considered neuroprotective in PD, and this neuroprotective mechanism may act by inhibiting intestinal inflammation. Therefore, the aim of this study was to evaluate the effect of curcumin on motor dysfunction and the loss of dopaminergic neurons in a PD mouse model, induced by N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) using open field test and pole test behavioral assessments and the immunofluorescence and Western blot methods. Moreover, the effects of curcumin on gastrointestinal dysfunction, gastric barrier function, pro-inflammatory cytokines, and the SIRT1/NRF2 pathway in intestinal tissues in a PD mouse model were assessed using fecal parameters and intestinal dynamics, immunofluorescence, ELISA, and Western blot. A motor impairment study of an MPTP-induced mouse group prior to treatment with curcumin had a lower total movement distance and a slow average speed, while there was no statistical difference in the curcumin group. After treatment with curcumin, the total movement distance and average speed improved, the tyrosine hydroxylase (TH) rate in the substantia nigra pars compacta (SNpc) and striatum were reduced, the pyroptosis of AIM2 and caspase-1 activations were inhibited, and intestinal inflammatory factors and intestinal inflammation were reduced. Curcumin improved gastrointestinal disorders and gastrointestinal barrier function in the MPTP-induced mice and reversed MPTP-induced motor dysfunction and dopaminergic neuron loss in mice. The above effects may be partly dependent on curcumin activation of the SIRT1/NRF2 pathway in the colon. This study provides a potential opportunity to develop new preventive measures and novel therapeutic approaches that could target the gut-brain axis in the context of PD and provide a new intervention in the treatment of Parkinson's disease.

Physicochemical, Structural, and In Vitro Gastrointestinal Tract Release Properties of Sodium Alginate-Based Cryogel Beads Filled with Hydroxypropyl Distarch Phosphate as a Curcumin Delivery System

The objectives of this study were to produce sodium alginate (SA)-based cryogel beads filled with different concentrations (0, 0.4, 1.0, and 2.5%, w/w) of hydroxypropyl distarch phosphate (HDP) as a curcumin delivery system and to investigate the physicochemical, structural, and in vitro gastrointestinal tract release properties of the cryogel beads. According to FT-IR analysis, the formation of ionic crosslinking between SA and Ca²⁺ and the presence of HDP were found. XRD analysis demonstrated the successful encapsulation of curcumin in the beads by observing the disappearance of the characteristic peaks of curcumin. SEM analysis results revelated that SA-based cryogel beads exhibited a denser internal structure as the HDP concentration was increased. The encapsulation efficiency of curcumin in SA cryogel beads filled with HDP concentration from 0% to 2.5% was increased from 31.95% to 76.66%, respectively, indicating that HDP can be a suitable filler for the encapsulation of curcumin in the production of SA-based cryogel beads. After exposure to simulated gastric fluid (SGF) and simulated intestinal fluid (SIF), the release rate of curcumin was decreased as HDP concentration was increased. Accordingly, SA-based cryogel beads filled with HDP can be utilized for the delivery system of curcumin in the food industry.

The Interaction of Polyphenols and the Gut Microbiota in Neurodegenerative Diseases

Polyphenols are secondary metabolites of plants and play a potential role in the prevention and treatment of neurodegenerative diseases (NND) such as Alzheimer's disease (AD) and Parkinson's disease (PD) due to their unique physiological functions such as acting as antioxidants, being anti-inflammatory, being neuroprotective, and promoting intestinal health. Since dietary polyphenols exist in plant foods in the form of glycosylation or esterification or are combined with polymers, they need to undergo extensive metabolism through phase I and phase II biotransformations by various intestinal enzymes, as well as metabolism by the intestinal microbiota before they can be fully absorbed. Polyphenols improve intestinal microbiota disorders by influencing the structure and function of intestinal microbiota, inducing beneficial bacteria to produce a variety of metabolites such as short-chain fatty acids (SCFAs), promoting the secretion of hormones and neurotransmitters, and playing an important role in the prevention and treatment of NND by affecting the microbe-gut-brain axis. We review the ways in which some polyphenols can change the composition of the intestinal microbiota and their metabolites in AD or PD animal models to exert the role of slowing down the progression of NND, aiming to provide evidence for the role of polyphenols in slowing the progression of NND via the microbiota-gut-brain (MGB) axis.

Benefits of dietary polyphenols in Alzheimer's disease

Alzheimer's disease (AD) is an irreversible progressive neurodegenerative disease affecting approximately 50 million people worldwide. It is estimated to reach 152 million by the year 2050. AD is the fifth leading cause of death among Americans age 65 and older. In spite of the significant burden the disease imposes upon patients, their families, our society, and our healthcare system, there is currently no cure for AD. The existing approved therapies only temporarily alleviate some of the disease's symptoms, but are unable to modulate the onset and/or progression of the disease. Our failure in developing a cure for AD is attributable, in part, to the multifactorial complexity underlying AD pathophysiology. Nonetheless, the lack of successful pharmacological approaches has led to the consideration of alternative strategies that may help delay the onset and progression of AD. There is increasing recognition that certain dietary and nutrition factors may play important roles in protecting against select key AD pathologies. Consistent with this, select nutraceuticals and phytochemical compounds have demonstrated anti-amyloidogenic, antioxidative, anti-inflammatory, and neurotrophic properties and as such, could serve as lead candidates for further novel AD therapeutic developments. Here we summarize some of the more promising dietary phytochemicals, particularly polyphenols that have been shown to positively modulate some of the important AD pathogenesis aspects, such as reducing β-amyloid plaques and neurofibrillary tangles formation, AD-induced oxidative stress, neuroinflammation, and synapse loss. We also discuss the recent development of potential contribution of gut microbiome in dietary polyphenol function.

The impact of herbal medicine in regulating intestinal flora on female reproductive disorders

As an important part of the human intestinal microecology, the intestinal flora is involved in a number of physiological functions of the host. Several studies have shown that imbalance of intestinal flora and its regulation of the intestinal barrier, intestinal immune response, and intestinal flora metabolites (short-chain fatty acids and bile acids) can affect the development and regression of female reproductive disorders. Herbal medicine has unique advantages in the treatment of female reproductive disorders such as polycystic ovary syndrome, endometriosis and premature ovarian insufficiency, although its mechanism of action is still unclear. Therefore, based on the role of intestinal flora in the occurrence and development of female reproduction-related diseases, the progress of research on the diversity, structure and composition of intestinal flora and its metabolites regulated by botanical drugs, Chinese herbal formulas and active ingredients of Chinese herbal medicines is reviewed, with a view to providing reference for the research on the mechanism of action of Chinese herbal medicines in the treatment of female reproductive disorders and further development of new herbal medicines.

Role of curcumin in the treatment of acute kidney injury: research challenges and opportunities

BACKGROUND

Acute kidney injury (AKI) is a common complication in clinical inpatients, and it continues a high morbidity and mortality rate despite many clinical treatment measures. AKI is triggered by infections, surgery, heavy metal exposure and drug side effects, but current chemical drugs often fall short of expectations for AKI treatment and have toxic side effects. Therefore, finding new interventions and treatments, especially of natural origin, is of remarkable clinical significance and application. The herbal monomer curcumin is a natural phenolic compound extracted from the plant Curcuma longa and showed various biological activities, including AKI. Furthermore, recent studies have shown that curcumin restores renal function by modulating the immune system and the release of inflammatory mediators, scavenging oxygen free radicals, reducing apoptosis and improving mitochondrial dynamics. However, curcumin has a low bioavailability, which limits its clinical application. For this reason, it is essential to investigate the therapeutic effects and molecular mechanisms of curcumin in AKI, as well as to improve its bioavailability for curcumin formulation development and clinical application.

PURPOSE

This review summarizes the sources, pharmacokinetics, and limitations in the clinical application of curcumin and explores methods to optimize its bioavailability using nanotechnology. In particular, the therapeutic effects and molecular mechanisms of curcumin on AKI are highlighted to provide a theoretical basis for AKI treatment in clinical practices.

METHODS

This review was specifically searched by means of a search of three databases (Web of Science, PubMed and Science Direct), till December 2021. Search terms were "Curcumin", "Acute kidney injury", "AKI", " Pharmacokinetics", "Mitochondria" and "Nano formulations". The retrieved data followed PRISMA criteria (preferred reporting items for systematic review) RESULTS: Studies have shown that curcumin responded to AKI-induced renal injury and restored renal tubular epithelial cell function by affecting multiple signaling pathways in AKI models induced by factors such as cisplatin, lipopolysaccharide, ischemia/reperfusion, gentamicin and potassium dichromate. Curcumin was able to affect NF-κB signaling pathway and reduce the expression of IL-1β, IL-6, IL-8 and TNF-α, thus preventing renal inflammatory injury. In the prevention of renal tubular oxidative damage, curcumin reduced ROS production by activating the activity of Nrf2, HO-1 and PGC-1α. In addition, curcumin restored mitochondrial homeostasis by upregulating OPA1 and downregulating DRP1 expression, while reducing apoptosis by inhibiting the caspase-3 apoptotic pathway. In addition, due to the low bioavailability and poor absorption of curcumin in vivo, curcumin nanoformulations including nanoparticles, liposomes, and polymeric micelles are formulated to improve the bioavailability.

CONCLUSION

This review provides new ideas for the use of curcumin in the prevention and treatment of AKI by modulating the molecular targets of several different cellular signaling pathways.