Sodium alginate capsulation increased brain delivery of probucol and suppressed neuroinflammation and neurodegeneration

To see or not to see: In vivo nanocarrier detection methods in the brain and their challenges

Nanoparticles have a great potential to significantly improve the delivery of therapeutics to the brain and may also be equipped with properties to investigate brain function. The brain, being a highly complex organ shielded by selective barriers, requires its own specialized detection system. However, a significant hurdle to achieve these goals is still the identification of individual nanoparticles within the brain with sufficient cellular, subcellular, and temporal resolution. This review aims to provide a comprehensive summary of the current knowledge on detection systems for tracking nanoparticles across the blood-brain barrier and within the brain. We discuss commonly employed in vivo and ex vivo nanoparticle identification and quantification methods, as well as various imaging modalities able to detect nanoparticles in the brain. Advantages and weaknesses of these modalities as well as the biological factors that must be considered when interpreting results obtained through nanotechnologies are summarized. Finally, we critically evaluate the prevailing limitations of existing technologies and explore potential solutions.

The therapeutic potential of probucol and probucol analogues in neurodegenerative diseases

Neurodegenerative disorders present complex pathologies characterized by various interconnected factors, including the aggregation of misfolded proteins, oxidative stress, neuroinflammation and compromised blood-brain barrier (BBB) integrity. Addressing such multifaceted pathways necessitates the development of multi-target therapeutic strategies. Emerging research indicates that probucol, a historic lipid-lowering medication, offers substantial potential in the realm of neurodegenerative disease prevention and treatment. Preclinical investigations have unveiled multifaceted cellular effects of probucol, showcasing its remarkable antioxidative and anti-inflammatory properties, its ability to fortify the BBB and its direct influence on neural preservation and adaptability. These diverse effects collectively translate into enhancements in both motor and cognitive functions. This review provides a comprehensive overview of recent findings highlighting the efficacy of probucol and probucol-related compounds in the context of various neurodegenerative conditions, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and cognitive impairment associated with diabetes.

Probucol neuroprotection against manganese-induced damage in adult Wistar rat brain slices

Manganese (Mn) is an abundant element used for commercial purposes and is essential for the proper function of biological systems. Chronic exposure to high Mn concentrations causes Manganism, a Parkinson's-like neurological disorder. The pathophysiological mechanism of Manganism remains unknown; however, it involves mitochondrial dysfunction and oxidative stress. This study assessed the neuroprotective effect of probucol, a hypolipidemic agent with anti-inflammatory and antioxidant properties, on cell viability and oxidative stress in slices of the cerebral cortex and striatum from adult male Wistar rats. Brain structure slices were kept separately and incubated with manganese chloride (MnCl2) and probucol to evaluate the cell viability and oxidative parameters. Probucol prevented Mn toxicity in the cerebral cortex and striatum, as evidenced by the preservation of cell viability observed with probucol (10 and 30 μM) pre-treatment, as well as the prevention of mitochondrial complex I inhibition in the striatum (30 μM). These findings support the protective antioxidant action of probucol, attributed to its ability to prevent cell death and mitigate Mn-induced mitochondrial dysfunction.

How to Develop Drug Delivery System Based on Carbohydrate Nanoparticles Targeted to Brain Tumors

Brain tumors are the most difficult to treat, not only because of the variety of their forms and the small number of effective chemotherapeutic agents capable of suppressing tumor cells, but also limited by poor drug transport across the blood-brain barrier (BBB). Nanoparticles are promising drug delivery solutions promoted by the expansion of nanotechnology, emerging in the creation and practical use of materials in the range from 1 to 500 nm. Carbohydrate-based nanoparticles is a unique platform for active molecular transport and targeted drug delivery, providing biocompatibility, biodegradability, and a reduction in toxic side effects. However, the design and fabrication of biopolymer colloidal nanomaterials have been and remain highly challenging to date. Our review is devoted to the description of carbohydrate nanoparticle synthesis and modification, with a brief overview of the biological and promising clinical outcomes. We also expect this manuscript to highlight the great potential of carbohydrate nanocarriers for drug delivery and targeted treatment of gliomas of various grades and glioblastomas, as the most aggressive of brain tumors.

Low-dose nano-gel incorporated with bile acids enhanced pharmacology of surgical implants

Aim: Major challenges to islet transplantation in Type 1 diabetes include host-inflammation, which results in failure to maintain survival and functions of transplanted islets. Therefore, this study investigated the applications of encapsulating the bile acid ursodeoxycholic acid (UDCA) with transplanted islets within improved nano-gel systems for Type 1 diabetes treatment. Materials & methods: Islets were harvested from healthy mice, encapsulated using UDCA-nano gel and transplanted into the diabetic mice, while the control group was transplanted encapsulated islets without UDCA. The two groups' survival plot, blood glucose, and inflammation and bile acid profiles were analyzed. Results & conclusion: UDCA-nano gel enhanced survival, glycemia and normalized bile acids' profile, which suggests improved islets functions and potential adjunct treatment for insulin therapy.

Research and Progress of Probucol in Nonalcoholic Fatty Liver Disease

With the development of the social economy over the last 30 years, non-alcoholic fatty liver disease (NAFLD) is affected by unhealthy living habits and eating styles and has gradually become an increasingly serious public health problem. It is very important to investigate the pathogenesis and treatment of NAFLD for the development of human health. Probucol is an antioxidant with a bis-phenol structure. Although probucol is a clinically used cholesterol-lowering and antiatherosclerosis drug, its mechanism has not been elucidated in detail. This paper reviews the chemical structure, pharmacokinetics and pharmacological research of probucol. Meanwhile, this paper reviews the mechanism of probucol in NAFLD. We also analyzed and summarized the experimental models and clinical trials of probucol in NAFLD. Although current therapeutic strategies for NAFLD are not effective, we hope that through further research on probucol, we will be able to find suitable treatments to solve this problem in the future.

Protective Effects of Probucol on Different Brain Cells Exposed to Manganese

Manganese (Mn) is an essential metal for many functions in the body. However, in excess, it can be neurotoxic and cause a Parkinson-like syndrome, known as manganism. Here, we aimed to identify a protective effect of probucol, a lipid-lowering agent with anti-inflammatory and antioxidant properties, against Mn-induced toxicity in human neuroblastoma (SH-SY5Y) and glioblastoma (C6) cell lines. The cells were incubated with increasing concentrations of Mn followed by probucol addition 1, 3, 6, and/or 24 h to assess the metal toxic doses and measure the protective effect of probucol against Mn-induced oxidative damage. Longer exposition to Mn showed decreased SH-SY5Y cellular viability in concentrations higher than 100 µM, and probucol was able to prevent this effect. The C6 cells were more sensitive to the Mn deleterious actions, decreasing the cell viability after 6 h of 500 µM Mn exposure. In addition, probucol prevents the complex I and II of the mitochondrial respiratory chain (MRC) inhibition caused by Mn and decreased the intracellular ROS production. Taken together, our results showed that Mn toxicity affects differently both cell lines and probucol has a protective effect against the oxidative imbalance in the central nervous system.

Biguanide Pharmaceutical Formulations and the Applications of Bile Acid-Based Nano Delivery in Chronic Medical Conditions

Biguanides, particularly the widely prescribed drug metformin, have been marketed for many decades and have well-established absorption profiles. They are commonly administered via the oral route and, despite variation in oral uptake, remain commonly prescribed for diabetes mellitus, typically type 2. Studies over the last decade have focused on the design and development of advanced oral delivery dosage forms using bio nano technologies and novel drug carrier systems. Such studies have demonstrated significantly enhanced delivery and safety of biguanides using nanocapsules. Enhanced delivery and safety have widened the potential applications of biguanides not only in diabetes but also in other disorders. Hence, this review aimed to explore biguanides’ pharmacokinetics, pharmacodynamics, and pharmaceutical applications in diabetes, as well as in other disorders.

Taurine Grafted Micro-Implants Improved Functions without Direct Dependency between Interleukin-6 and the Bile Acid Lithocholic Acid in Plasma

A recent study showed an association between diabetes development and the bile acid lithocholic acid (LCA), while another study demonstrated positive biological effects of the conjugated bile acid, taurocholic acid (TCA), on pancreatic cells. Thus, this study aimed to encapsulate TCA with primary islets (graft) and study the biological effects of the graft, post-transplantation, in diabetic mice, including effects on LCA concentrations. Sixteen mature adult mice were made diabetic and randomly divided into two equal groups, control and test (transplanted encapsulated islets without or with TCA). Graft pharmaceutical features pre-transplantation, and biological effects including on LCA concentrations post-transplantation, were measured. TCA-microcapsules had an oval shape and similar size compared with the control. The treatment group survived longer, showed improved glucose and interleukin-6 concentrations, and lower LCA concentrations in plasma, large intestine, faeces, liver and spleen, compared with control. Results suggest that TCA incorporation with islets encapsulated graft exerted beneficial effects, but there was no direct and significant dependency between concentrations of interleukin-6 and LCA.

Effects and mechanisms of probucol on aging-related hippocampus-dependent cognitive impairment

BACKGROUND

In the present study, we aimed to investigate the effects of probucol on aging-related hippocampus-dependent cognitive impairment and explore the potential mechanisms.

METHODS

D-galactose (100 mg/kg, once daily for 6 weeks) was subcutaneously injected to induce aging in mice. Then the mice were administered with probucol or vehicle once a day for 2 weeks. The hippocampus-related cognition was evaluated with Morris water maze test, novel object recognition test, and contextual fear conditioning test. Moreover, synaptic plasticity was assessed, and RNA-sequencing was applied to further explore the molecular mechanisms.

RESULTS

Aging mice induced by D-galactose showed conspicuous learning and memory impairment, which was significantly ameliorated by probucol. Meanwhile, probucol enhanced the spine density and dendritic branches, improved long-term potentiation, and increased the expression of PSD95 of aging mice. Probucol regulated 70 differentially expressed genes compared to D-galactose group, of which 38 genes were upregulated and 32 genes were downregulated. At last, RNA-sequencing results were verified by quantitative reverse transcription-polymerase chain reaction.

CONCLUSIONS

Probucol improved learning and memory in aging mice through enhancing synaptic plasticity and regulating gene expression, indicating the potential application of probucol to prevent and treat aging-related disorders.

Chemotherapy-induced hearing loss: the applications of bio-nanotechnologies and bile acid-based delivery matrices

Advancement in the prevention of chemotherapy-induced hearing loss has proposed new nano-based delivery matrices that can target inner ear regions most damaged by chemotherapy. Chemotherapy agents (e.g., cisplatin) induce increased reactive oxygen species formation in the inner ear that damage sensory hair cells and result in irreversible hearing impairment. Exogenous antioxidants (e.g., Probucol and metformin) have been shown to block the formation of these reactive oxygen species. Delivery of these drugs in effective concentrations remains a challenge. Microencapsulation in combination with drug excipients provides one technique to effectively deliver these drugs. This paper investigates the use of probucol and metformin in combination with drug excipients for novel, inner ear, delivery.

A Review on Recent Advancement on Age-Related Hearing Loss: The Applications of Nanotechnology, Drug Pharmacology, and Biotechnology

Aging is considered a contributing factor to many diseases such as cardiovascular disease, Alzheimer’s disease, and hearing loss. Age-related hearing loss, also termed presbycusis, is one of the most common sensory impairments worldwide, affecting one in five people over 50 years of age, and this prevalence is growing annually. Associations have emerged between presbycusis and detrimental health outcomes, including social isolation and mental health. It remains largely untreatable apart from hearing aids, and with no globally established prevention strategies in the clinical setting. Hence, this review aims to explore the pathophysiology of presbycusis and potential therapies, based on a recent advancement in bile acid-based bio-nanotechnologies. A comprehensive online search was carried out using the following keywords: presbycusis, drugs, hearing loss, bile acids, nanotechnology, and more than 150 publications were considered directly relevant. Evidence of the multifaceted oxidative stress and chronic inflammation involvement in cellular damage and apoptosis that is associated with a loss of hair cells, damaged and inflamed stria vascularis, and neuronal signalling loss and apoptosis continues to emerge. New robust and effective therapies require drug delivery deeper into the various layers of the cochlea. Bile acid-based nanotechnology has gained wide interest in its permeation-enhancing ability and potential for numerous applications in treating presbycusis.

Sodium alginate microencapsulation improves the short-term oral bioavailability of cannabidiol when administered with deoxycholic acid

BACKGROUND

Cannabidiol (CBD) confers therapeutic effects in some neurological disorders via modulation of inflammatory, oxidative and cell-signalling pathways. However, CBD is lipophilic and highly photooxidative with low oral bioavailability in plasma and brain. In this study, we aimed to design and test a CBD microencapsulation method as a drug delivery strategy to improve the absorption of CBD. Additionally, we evaluated the brain uptake of CBD capsules when administered alongside capsules containing a permeation-modifying bile acid, deoxycholic acid (DCA).

METHODS

Microcapsules containing either CBD or DCA were formed using the ionic gelation method with 1.5% sodium alginate formulations and 100 mM calcium chloride. C57BL/6J wild type mice randomly assigned to three treatment groups (3-4 mice per group) were administered CBD in the following preparations: 1) CBD capsules, 2) CBD capsules + DCA capsules and 3) naked CBD oil (control). To assess the short-term bioavailability of CBD, plasma and brain samples were collected at 0.3, 1 and 3 hours post administration and CBD levels were analysed with liquid chromatography mass spectrometer.

RESULTS

We produced spherical capsules at 400 ± 50 μm in size. The CBD capsules were calculated to have a drug loading of 2% and an encapsulation efficiency of 23%. Mice that received CBD capsules + DCA capsules showed a 40% and 47% increase in CBD plasma concentration compared to mice on CBD capsules and naked CBD oil, respectively. Furthermore, the CBD capsules + DCA capsules group showed a 48% and 25% increase in CBD brain concentration compared to mice on CBD capsules and naked CBD oil, respectively. In mice treated with CBD capsules + DCA capsules, the brain CBD concentration peaked at 0.3 hours with a 300% increased availability compared to CBD capsules and naked CBD oil groups, which peaked at 1 hour after administration.

CONCLUSIONS

The microencapsulation method combined with a permeation enhancer, DCA increased the short-term bioavailability of CBD in plasma and brain.

Microencapsulation of Coenzyme Q10 and bile acids using ionic gelation vibrational jet flow technology for oral delivery

Developing new delivery dosage forms with robust delivery and safety profiles remains a challenge to the pharmaceutical industry in terms of optimum gut absorption, consistent dosing and bioavailability; particularly for orally administered drugs that are poorly water soluble. Coenzyme Q10 is an example of a poorly water-soluble compound with low bioavailability, and significant inter-individual variation after oral administration; limiting its optimum efficacy, as a powerful antioxidant with significant promise in treating hearing disorders. Microencapsulation technology is one way to optimize drug bioavailability and absorption profile. One example is Ionic Gelation Vibrational Jet Flow techniques, using new encapsulating parameters to determine the nature of formed capsules. Bile acids are an example of an excipient that can be used to improve membrane permeability; and will be examined. This review addresses the applications of microencapsulation technology on oral delivery and efficacy profiles of poorly water-soluble drugs, focusing on Coenzyme Q10.

Alginate-based drug oral targeting using bio-micro/nano encapsulation technologies

INTRODUCTION

Oral delivery is the most common administrated drug delivery path. However, oral administration of lipophilic drugs has some limitations: they have poor dose-response due to low and varied dissolution kinetics and oral bioavailability with sub-optimal dissolution within the aqueous gastrointestinal microenvironment. Therefore, there is a need for robust formulating methods that protect the drug until it reaches to its optimum absorption site, allowing its optimum pharmacological effects via increasing its intestinal permeation and bioavailability.

AREA COVERED

Herein, we provide insights on orally administered lipophilic drug delivery systems. The detailed description of the obstacles associated with the oral bioavailability of lipophilic drugs are also discussed. Following this, techniques to overcome these obstacles with much emphasis on optimal safety and efficacy are addressed. Newly designed ionic vibrational jet flow encapsulation technology has enormous growth in lipophilic drug delivery systems, which is discussed thereafter.

EXPERT OPINION

Researchers have shown interest in drug's encapsulation. A combination of drug-bile acid and microencapsulation methods can be one promising strategy to improve the oral delivery of lipophilic drugs. However, the most critical aspect of this approach is the selection of bile acids, polymer, and encapsulation technology.

Histological effects of pharmacologically active human bile acid nano/micro-particles in Type-1 diabetes

Aim: Gliclazide (G) is a drug prescribed for Type 2 diabetics, although recent studies suggest it has desirable effects in both types of diabetes, Type 1 diabetes and Type 2 diabetes. G has an inconsistent absorption due to poor formulation and bile acids (BAs) have shown significant promise in drug formulation optimization. Hence, the study aimed to examine G effects on histopathological, anti-inflammatory and antidiabetic effects when encapsulated with BAs. Materials & methods: Rats were randomized into eight groups, of which seven were made Type 1 diabetes and treated with various BA-based treatments. Tissue histopathology, inflammation and the bile acid profile were analyzed. Results & conclusion: G capsules showed no histological but the most anti-inflammatory effects, which suggest significant beneficial effects in diabetes treatment.

Stability and biological testing of taurine-conjugated bile acid antioxidant microcapsules for diabetes treatment

AIM

Taurine-conjugated bile acids possess positive formulation-stabilization effects, which are desirable in diabetes treatments. The taurine-conjugated bile acid, taurocholic acid (TCA), has shown promising formulation-stabilizing effects on the delivery of the antioxidant drug, probucol (PB), but success is limited due to its poor release profile. This study aimed to design new PB-TCA formulations using new polymers, and examine antioxidant and antidiabetic effects using β-cells for PB with or without TCA.

MATERIALS AND METHODS

Different formulations using alginate-insoluble esters of polymethylacrylate polymers encapsulating PB and TCA were developed, microencapsulated and examined for stability and biological activity.

RESULTS

TCA addition to new PB matrices improved osmotic and mechanical properties, and this effect was dependent on polymethylacrylate composition and concentration.

CONCLUSION

TCA can optimize the oral delivery of anti-diabetic compounds.

Modulatory Nano/Micro Effects of Diabetes Development on Pharmacology of Primary and Secondary Bile Acids Concentrations

BACKGROUND

Recent studies have suggested that hyperglycaemia influences the bile acid profile and concentrations of secondary bile acids in the gut.

INTRODUCTION

This study aimed to measure changes in the bile acid profile in the gut, tissues, and faeces in type 1 Diabetes (T1D) and Type 2 Diabetes (T2D).

METHODS

T1D and T2D were established in a mouse model. Twenty-one seven-weeks old balb/c mice were randomly divided into three equal groups, healthy, T1D and T2D. Blood, tissue, urine and faeces samples were collected for bile acid measurements.

RESULTS

Compared with healthy mice, T1D and T2D mice showed lower levels of the primary bile acid, chenodeoxycholic acid, in the plasma, intestine, and brain, and higher levels of the secondary bile acid, lithocholic acid, in the plasma and pancreas. Levels of the bile acid ursodeoxycholic acid were undetected in healthy mice but were found to be elevated in T1D and T2D mice.

CONCLUSION

Bile acid profiles in other organs were variably influenced by T1D and T2D development, which suggests similarity in effects of T1D and T2D on the bile acid profile, but these effects were not always consistent among all organs, possibly since feedback mechanisms controlling enterohepatic recirculation and bile acid profiles and biotransformation are different in T1D and T2D.

A second-generation micro/nano capsules of an endogenous primary un-metabolised bile acid, stabilized by Eudragit-alginate complex with antioxidant compounds

Bile acids (BAs) are amphiphilic compounds and of recently have demonstrated wide range of formulation stabilizing effects. A recent study showed that primary un-metabolised bile acids (PUBAs) have β-cell protective effects, and synergistic antidiabetic effects when combined with antioxidant and anti-inflammatory drugs, such as probucol (PB). Thus, this study aimed to design and test microcapsules containing a PUBA incorporated with PB and an alginate-Eudragit matrix.

Six types of microcapsules were developed without (control) or with (test) PUBA, and tested for internal and external features and β-cell protective effects.

The incorporation of PB-alginate-Eudragit with PUBA produced stable microcapsules but did not exert consistent positive effects on cell viability in the hyperglycaemic state, which suggests that PUBA in alginate-Eudragit matrices did not exhibit synergistic effects with PB nor exerted antidiabetic effects.

Probucol-poly(meth)acrylate-bile acid nanoparticles increase IL-10, and primary bile acids in prediabetic mice

Aim: Common features in insulin-resistance diabetes include inflammation and liver damage due to bile acid accumulation. Results & methodology: This study aimed to test in vivo pharmacological effects of combining two drugs, ursodeoxycholic acid that has bile acid regulatory effects, and probucol (PB) that has potent anti-oxidative stress effects, using a new poly(meth)acrylate nano-targeting formulation on prediabetic mice. Mice were made diabetic and were fed daily with either PB, nanoencapsulated PB or nanoencapsulated PB-ursodeoxycholic acid before blood, tissues, urine and feces were collected for inflammation and bile acid measurements. The nanoencapsulated PB-ursodeoxycholic acid formulation increased plasma IL-10, and increased the concentration of primary bile acids in the liver and heart. Conclusion: Results suggest potential applications in regulating IL-10 in insulin-resistance prediabetes.

Bile acid-polymer-probucol microparticles: protective effect on pancreatic β-cells and decrease in type 1 diabetes development in a murine model

Studies in our laboratory have shown potential applications of the anti-atherosclerotic drug probucol (PB) in diabetes due to anti-inflammatory and β-cell protective effects. The anti-inflammatory effects were optimized by incorporation of the anti-inflammatory bile acid, ursodeoxycholic acid (UDCA). This study aimed to test PB absorption, tissue accumulation profiles, effects on inflammation and type 1 diabetes prevention when combined with UDCA. Balb/c mice were divided into three equal groups and gavaged daily PB powder, PB microcapsules or PB-UDCA microcapsules for one week, at a constant dose. Mice were injected with a single dose of intraperitoneal/subcutaneous alloxan to induce type-1 diabetes and once diabetes was confirmed, treatments were continued for 3 days. Mice were euthanized and blood and tissues collected for analysis of PB and cytokine levels. The PB-UDCA group showed the highest PB concentrations in blood, gut, liver, spleen, brain, and white adipose tissues, with no significant increase in pancreas, heart, skeletal muscles, kidneys, urine or feces. Interferon gamma in plasma was significantly reduced by PB-UDCA suggesting potent anti-inflammatory effects. Blood glucose levels remained similar after treatments, while survival was highest among the PB-UDCA group. Our findings suggest that PB-UDCA resulted in best PB blood and tissue absorption and reduced inflammation.

An in vivo pharmacological study: Variation in tissue-accumulation for the drug probucol as the result of targeted microtechnology and matrix-acrylic acid optimization and stabilization techniques

Type 2 diabetes (T2D) is characterised by β-cell damage and hyperglycaemia. The lipophilic drug, probucol, has shown significant β-cell protective and potential antidiabetic effects, which were enhanced by hydrophilic bile acid incorporation using taurocholic acid and chenodeoxycholic acid. However, probucol has severe cardiotoxicity and a variable absorption profile, which limit its potential applications in T2D. Accordingly, this study aimed to design multiple formulations to optimise probucol oral delivery in T2D and test their effects on probucol absorption and accumulation in the heart. Adult male mice were given a high fat diet (HFD), and a week later, injected with a single dose of alloxan to accelerate T2D development, and once diabetes confirmed, divided into three groups (six to seven mice each). The groups were gavaged a daily dose of probucol powder, probucol microcapsules, or probucol-bile acid microcapsules for three months, and euthanized; and blood, tissues, and feces collected for blood glucose and probucol concentration analyses. Probucol concentrations in plasma were similar among all the groups. Groups given probucol microcapsules and probucol-bile acid microcapsules showed significant reduction in probucol accumulation in the heart compared with the group given probucol powder (p<0.05). Probucol microencapsulation with or without bile acids reduced its accumulation in heart tissues, without changing plasma concentrations, which may be beneficial in reducing its cardiotoxicity and optimise its potential applications in T2D.