Nanoliposome improves inhibitory effects of naringenin on nonalcoholic fatty liver disease in mice

An herbal formulation "Shugan Xiaozhi decoction" ameliorates methionine/choline deficiency-induced nonalcoholic steatohepatitis through regulating inflammation and apoptosis-related pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Shugan Xiaozhi (SGXZ) decoction is a traditional Chinese medicine used for treating nonalcoholic steatohepatitis (NASH). It has been used clinically for over 20 years and proved to be effective; however, the molecular mechanism underlying the effects of SGXZ decoction remains unclear.

AIM OF THE STUDY

We analyzed the chemical components, core targets, and molecular mechanisms of SGXZ decoction to improve NASH through network pharmacology and in vivo experiments.

MATERIALS AND METHODS

The chemical components, core targets, and related signaling pathways of SGXZ decoction intervention in NASH were predicted using network pharmacology. Molecular docking was performed to verify chemical components and their core targets. The results were validated in the NASH model treated with SGXZ decoction. Mouse liver function was assessed by measuring ALT and AST levels. TC and TG levels were determined to evaluate lipid metabolism, and lipid deposition was assessed via oil red O staining. Mouse liver damage was determined via microscopy following hematoxylin and eosin staining. Liver fibrosis was assessed via Masson staining. Western blot (WB) and immunohistochemical (IHC) analyses were performed to detect inflammation and the expression of apoptosis-related proteins, including IL-1β, IL-6, IL-18, TNF-α, MCP1, p53, FAS, Caspase-8, Caspase-3, Caspase-9, Bax, Bid, Cytochrome c, Bcl-2, and Bcl-XL. In addition, WB and IHC were used to assess protein expression associated with the TLR4/MyD88/NF-κB pathway.

RESULTS

Quercetin, luteolin, kaempferol, naringenin, and nobiletin in SGXZ decoction were effective chemical components in improving NASH, and TNF-α, IL-6, and IL-1β were the major core targets. Molecular docking indicated that these chemical components and major core targets might interact. KEGG pathway analysis showed that the pathways affected by SGXZ decoction, primarily including apoptosis and TLR4/NF-κB signaling pathways, interfere with NASH. In vivo experiments indicated that SGXZ decoction considerably ameliorated liver damage, fibrosis, and lipid metabolism disorder in MCD-induced NASH mouse models. In addition, WB and IHC verified the underlying molecular mechanisms of SGXZ decoction as predicted via network pharmacology. SGXZ decoction inhibited the activation of apoptosis-related pathways in MCD-induced NASH mice. Moreover, SGXZ decoction suppressed the activation of TLR4/MyD88/NF-κB pathway in MCD-induced NASH mice.

CONCLUSION

SGXZ decoction can treat NASH through multiple targets and pathways. These findings provide new insights into the effective treatment of NASH using SGXZ decoction.

Nonalcoholic fatty liver disease: Current therapies and future perspectives in drug delivery

Nonalcoholic fatty liver disease (NAFLD) affects approximately 25% of the adult population worldwide. This pathology can progress into end-stage liver disease with life-threatening complications, and yet no pharmacologic therapy has been approved. NAFLD is commonly characterized by excessive fat accumulation in the liver and is in closely associated with insulin resistance and metabolic disorders, which suggests that NAFLD is the hepatic manifestation of metabolic syndrome. Regarding treatment options, the current validated strategy relies on lifestyle modifications (exercise and diet restrictions). Although there are no approved drug-based treatments, several clinical trials are ongoing. Novel targets are being discovered, and the repurposing of drugs that show promising effects in NAFLD is starting to gain more interest. The field of nanotechnology has been growing at an increasing rate, with new and more efficient drug delivery strategies being developed for NAFLD treatment. Nanocarriers can easily encapsulate drugs that need to be better protected from the organism to exert their effect or that need help at reaching their target, thereby helping achieve a better bioavailability. Drug delivery systems can also be designed to target the site of the disease, in this case, the liver. In this review, we focus on the current knowledge of NAFLD pathology, the targets being considered for clinical trials, and the current guidelines and ongoing clinical trials, with a specific focus on potential oral treatments for NAFLD using promising drug delivery strategies.

Preventive and therapeutic effects of natural products and herbal extracts on nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

Nonalcoholic fatty liver disease (NAFLD) is a common condition that is prevalent in patients who consume little or no alcohol, and is characterized by excessive fat accumulation in the liver. The disease is becoming increasingly common with the rapid economic development of countries. Long-term accumulation of excess fat can lead to NAFLD, which represents a global health problem with no effective therapeutic approach. NAFLD is a complex, multifaceted pathological process that has been the subject of extensive research over the past few decades. Herbal medicines have gained attention as potential therapeutic agents to prevent and treat NAFLD due to their high efficacy and low risk of side effects. Our overview is based on a PubMed and Web of Science database search as of Dec 22 with the keywords: NAFLD/NASH Natural products and NAFLD/NASH Herbal extract. In this review, we evaluate the use of herbal medicines in the treatment of NAFLD. These natural resources have the potential to inform innovative drug research and the development of treatments for NAFLD in the future.

Modulating Inflammation-Mediated Diseases via Natural Phenolic Compounds Loaded in Nanocarrier Systems

The global increase and prevalence of inflammatory-mediated diseases have been a great menace to human welfare. Several works have demonstrated the anti-inflammatory potentials of natural polyphenolic compounds, including flavonoid derivatives (EGCG, rutin, apigenin, naringenin) and phenolic acids (GA, CA, etc.), among others (resveratrol, curcumin, etc.). In order to improve the stability and bioavailability of these natural polyphenolic compounds, their recent loading applications in both organic (liposomes, micelles, dendrimers, etc.) and inorganic (mesoporous silica, heavy metals, etc.) nanocarrier technologies are being employed. A great number of studies have highlighted that, apart from improving their stability and bioavailability, nanocarrier systems also enhance their target delivery, while reducing drug toxicity and adverse effects. This review article, therefore, covers the recent advances in the drug delivery of anti-inflammatory agents loaded with natural polyphenolics by the application of both organic and inorganic nanocarriers. Even though nanocarrier technology offers a variety of possible anti-inflammatory advantages to naturally occurring polyphenols, the complexes' inherent properties and mechanisms of action have not yet been fully investigated. Thus, expanding the quest on novel natural polyphenolic-loaded delivery systems, together with the optimization of complexes' activity toward inflammation, will be a new direction of future efforts.

Recent developments in citrus bioflavonoid encapsulation to reinforce controlled antioxidant delivery and generate therapeutic uses: Review

Citrus fruits contain numerous antioxidative biomolecules including phenolic acids, flavonols, flavanones, polymethoxyflavones (PMFs), and their derivatives. Previous in vitro and in vivo studies thoroughly investigated the antioxidant and therapeutic potential of bioflavonoids extracted from different citrus varieties and fruit fractions. Major bioflavonoids such as hesperidin, naringin, naringenin, and PMFs, had restricted their incorporation into food and health products due to their poor solubility, chemical stability and bioavailability. Considering these limitations, modern encapsulation methodologies such as hydrogelation, liposomal interactions, emulsifications, and nanoparticles have been designed to shield bioflavonoids with improved target distribution for therapeutic enhancements. The size, durability, and binding efficiency of bioflavonoid-loaded encapsulates were acquired by the optimized chemical and instrumental parameters such as solubility, gelation, dispersion, extrusion, and drying. Bioflavonoid-enriched encapsulates have been also proven to be effective against cancer, inflammation, neurodegeneration, and various other illnesses. However, in the future, newer natural binding agents with higher binding capacity might accelerate the encapsulating potential, controlled release, and enhanced bioavailability of citrus bioflavonoids. Overall, these modern encapsulation systems are currently leading to a new era of diet-based medicine, as demand for citrus fruit-based nutritional supplements and edibles grows.

Nanodelivery of Dietary Polyphenols for Therapeutic Applications

Advancement in nanotechnology has unleashed the therapeutic potentials of dietary polyphenols by enhancing bioavailability, improving biological half-life, and allowing site-specific drug delivery. In this review, through citation of relevant literature reports, we discuss the application of nano-pharmaceutical formulations, such as solid lipid nanoparticles, nano-emulsions, nano-crystals, nano-polymersomes, liposomes, ethosomes, phytosomes, and invasomes for dietary polyphenols. Following this, we highlight important studies concerning different combinations of nano formulations with dietary polyphenols (also known as nanophytopolyphenols). We also provide nano-formulation paradigms for enhancing the physicochemical properties of dietary polyphenols. Finally, we highlight the latest patents that were granted on nano-formulations of dietary polyphenols. Based on our review, we observe that nanosized delivery of herbal constituents, spices, and dietary supplements have the ability to improve biological processes and address issues connected with herbal treatments.

Enhanced Antioxidant Effects of Naringenin Nanoparticles Synthesized using the High-Energy Ball Milling Method

Naringenin, one of the flavonoid components, is majorly found in and obtained from grapefruits and oranges. Naringenin also acts as a potent antioxidant, which possesses hypolipidemic as well as anti-inflammatory potential. Naringenin reduces the expressions of several inflammatory mediators, viz., NF-κB, cycloxygenase-2, and other cytokine mediators. In spite of having various biological effects, the clinical application of naringenin is restricted due to its very poor aqueous solubility. In the present study, the high-energy ball milling method was employed for the preparation of naringenin nanoparticles without using any chemical with an aim to enhance the anti-oxidant potential of naringenin. The milled naringenin nanoparticles were characterized for their physicochemical properties using scanning electron microscopy (SEM) and X-ray diffraction. Additionally, the effects of milling time and temperature were further assessed on the solubility of crude and milled naringenin samples. The antioxidant potential of milled naringenin was evaluated with various assays such as DHE, DCFDA, and cleaved caspase-3 using SH-SY5Y human neuroblastoma cells. The nanoparticle size of naringenin after milling was confirmed using SEM analysis. Crystalline peaks for milled and crude samples of naringenin also established that both the naringenin forms were in the crystalline form. The solubility of naringenin was enhanced depending on the milling time and temperature. Moreover, crude and milled naringenin were found to be cytocompatible up to doses of 120 μM each for the duration of 24 and 48 h. It was also observed that milled naringenin at the doses of 1, 2, and 5 μM significantly reduced the levels of reactive oxygen species (ROS) generated by H₂O₂ and exhibited superior ROS scavenging effects as compared to those of crude or un-milled forms of naringenin. Furthermore, milled naringenin at the doses of 1 and 2 μM inhibited H₂O₂-induced cell death, as shown by immunofluorescence staining of cleaved caspase-3 and Annexin-V PI flow cytometry analysis. Conclusively, it could be suggested that the size reduction of naringenin using high-energy ball milling techniques substantially enhanced the antioxidant potential as compared to naïve or crude naringenin, which may be attributed to its enhanced solubility due to reduced size.

Effects of naringenin supplementation on cardiovascular risk factors in overweight/obese patients with nonalcoholic fatty liver disease: a pilot double-blind, placebo-controlled, randomized clinical trial

OBJECTIVE

Although several experimental models have suggested promising pharmacological effects of naringenin in the management of obesity and its related disorders, the effects of naringenin supplementation on cardiovascular disorders as one of the main complications of nonalcoholic fatty liver disease (NAFLD) are yet to be examined in humans.

METHODS

In this double-blind, placebo-controlled, randomized clinical trial, 44 overweight/obese patients with NAFLD were equally allocated into either naringenin or placebo group for 4 weeks. Cardiovascular risk factors including atherogenic factors, hematological indices, obesity-related parameters, blood pressure, and heart rate were assessed pre- and postintervention.

RESULTS

The atherogenic index of plasma value, serum non-HDL-C levels as well as total cholesterol/high-density lipoprotein cholesterol (HDL-C), triglyceride/HDL-C, low-density lipoprotein cholesterol/HDL-C, and non-HDL-C/HDL-C ratios were significantly reduced in the intervention group, compared to the placebo group post intervention (P < 0.05). Moreover, there was a significant reduction in BMI and visceral fat level in the intervention group when compared with the placebo group (P = 0.001 and P = 0.039, respectively). Furthermore, naringenin supplementation could marginally reduce systolic blood pressure (P = 0.055). Mean corpuscular hemoglobin increased significantly in the naringenin group compared to the placebo group at the endpoint (P = 0.023). Supplementation with naringenin also resulted in a marginally significant increase in the mean corpuscular hemoglobin concentration when compared with the placebo group (P = 0.050). There were no significant between-group differences for other study outcomes post intervention.

CONCLUSION

In conclusion, these data indicate that naringenin supplementation may be a promising treatment strategy for cardiovascular complications among NAFLD patients. However, further trials are warranted.

Design of Hepatic Targeted Drug Delivery Systems for Natural Products: Insights into Nomenclature Revision of Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD), recently renamed metabolic-dysfunction-associated fatty liver disease (MAFLD), affects a quarter of the worldwide population. Natural products have been extensively utilized in treating NAFLD because of their distinctive advantages over chemotherapeutic drugs, despite the fact that there are no approved drugs for therapy. Notably, the limitations of many natural products, such as poor water solubility, low bioavailability in vivo, low hepatic distribution, and lack of targeted effects, have severely restricted their clinical application. These issues could be resolved via hepatic targeted drug delivery systems (HTDDS) that boost clinical efficacy in treating NAFLD and decrease the adverse effects on other organs. Herein an overview of natural products comprising formulas, single medicinal plants, and their crude extracts has been presented to treat NAFLD. Also, the clinical efficacy and molecular mechanism of active monomer compounds against NAFLD are systematically discussed. The targeted delivery of natural products via HTDDS has been explored to provide a different nanotechnology-based NAFLD treatment strategy and to make suggestions for natural-product-based targeted nanocarrier design. Finally, the challenges and opportunities put forth by the nomenclature update of NAFLD are outlined along with insights into how to improve the NAFLD therapy and how to design more rigorous nanocarriers for the HTDDS. In brief, we summarize the up-to-date developments of the NAFLD-HTDDS based on natural products and provide viewpoints for the establishment of more stringent anti-NAFLD natural-product-targeted nanoformulations.

Effects of naringenin supplementation in overweight/obese patients with non-alcoholic fatty liver disease: study protocol for a randomized double-blind clinical trial

Introduction

Non-alcoholic fatty liver disease (NAFLD) is one of the main causes of chronic liver disease worldwide. Flavonoids, a group of natural compounds, have garnered a great deal of attention in the management of NAFLD because of their profitable effects on glucose and lipid metabolism, inflammation, and oxidative stress which are the pivotal pathophysiological pathways in NAFLD. Naringenin is a citrus-derived flavonoid with a broad spectrum of potential biological effects including anti-inflammatory and antioxidant properties, which may exert protective effects against NAFLD. The present clinical trial aims to examine the efficacy of naringenin supplementation on plasma adiponectin and neurogulin-4 (NRG-4) concentrations, metabolic parameters, and liver function indices in overweight/obese patients with NAFLD.

Methods and analysis

This is a double-blind, randomized, placebo-controlled clinical study that will investigate the impacts of naringenin supplementation in overweight/obese patients with NAFLD. Liver ultrasonography will be applied to diagnose NAFLD. Forty-four eligible overweight/obese subjects with NAFLD will be selected and randomly assigned to receive naringenin capsules or identical placebo (each capsule contains 100 mg of naringenin or cellulose), twice daily for 4 weeks. Participants will be asked to remain on their usual diet and physical activity. Safety of naringenin supplementation was confirmed by the study pharmacist. The primary outcome of this study is changes in adiponectin circulating levels. The secondary outcomes include changes in NRG-4 levels, liver function indices, metabolic parameters, body weight, body mass index (BMI), waist circumference (WC), blood pressure, and hematological parameters. Statistical analysis will be conducted using the SPSS software (version 25), and P value less than 0.05 will be regarded as statistically significant.

Discussion

We hypothesize that naringenin administration may be useful for treating NAFLD by modulating energy balance, glucose and lipid metabolism, oxidative stress, and inflammation through different mechanisms. The current trial will exhibit the effects of naringenin, whether negative or positive, on NAFLD status.

Ethical aspects

The current trial received approval from the Medical Ethics Committee of Tehran University of Medical Sciences, Tehran, Iran (IR.TUMS.MEDICNE.REC.1399.439).

Trial registration

Iranian Registry of Clinical Trials IRCT201311250155336N12. Registered on 6 June 2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05784-7.

The Emerging Role of Nanomedicine in the Management of Nonalcoholic Fatty Liver Disease: A State-of-the-Art Review

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disease that can lead to end-stage liver disease needing a liver transplant. Many pharmacological approaches are used to reduce the disease progression in NAFLD. However, current strategies remain ineffective to reverse the progression of NAFLD completely. Employing nanoparticles as a drug delivery system has demonstrated significant potential for improving the bioavailability of drugs in the treatment of NAFLD. Various types of nanoparticles are exploited in this regard for the management of NAFLD. In this review, we cover the current therapeutic approaches to manage NAFLD and provide a review of recent up-to-date advances in the uses of nanoparticles for the treatment of NAFLD.

Nanonaringenin and Vitamin E Ameliorate Some Behavioral, Biochemical, and Brain Tissue Alterations Induced by Nicotine in Rats

Nicotine is the major alkaloid present in cigarettes that induces various biochemical and behavioral changes. Nanonaringenin (NNG) and vitamin E are antioxidants that are reported to mitigate serious impairments caused by some toxins and oxidants. Thus, we aimed to investigate the efficacy of NNG, vitamin E, and their combinations to ameliorate behavioral, biochemical, and histological alterations induced by nicotine in rats. Adult male albino rats were randomly grouped into six equal groups (10 rats/group): control, N (nicotine 1 mg/kg b.w./day S/C from 15^th to 45^th day, 5 days a week), NNG (25 mg/kg b.w./day orally for 45 days), N + NNG, N + E (nicotine + vitamin E 200 mg/kg b.w./day orally), and N + NNG + E (nicotine + NNG + vitamin E at the aforementioned doses). Behavioral tests were conducted on day 15 and 30 postnicotine injection, while memory tests, brain neurotransmitters, antioxidants, and histopathological examination were examined at day 30 only. As a result, nicotine impaired rats' activity (hypoactivity and hyperactivity) and memory, induced anxiolytic and anxiogenic effects on rats, and altered neurotransmitters (acetylcholinesterase, serotonin, and dopamine), and redox markers (MDA, H₂O₂, GSH, and catalase) levels in brain homogenates. Thickening and congestion of the meninges and degeneration of the cerebral neurons and glia cells were observed. Cosupplementation with NNG, vitamin E, and their combination with nicotine was beneficial in the alleviation of activity impairments and improved short memory and cognition defects and exploratory behaviors. Our results indicate the antioxidant potential of NNG and vitamin E by modulating redox markers and neurotransmitters in the brain. Thus, data suggest that the prophylactic use of NNG, vitamin E, and/or their combination for (45 days) may have a successful amelioration of the disrupted behavior and cognition and biochemical and histopathological alterations induced by nicotine.

HPMC improves protective effects of naringenin and isonicotinamide co-crystals against abdominal aortic aneurysm

PURPOSE

Abdominal aortic aneurysm (AAA) rupture is one of the most common causes of mortality in cardiovascular diseases, but currently there is no approved drug for AAA treatment or prevention in the clinic. Naringenin (NGN) has been reported to have anti-AAA effects. However, water solubility and in vivo absorption of NGN are not satisfactory, which leads to its low bioavailability, thus affecting its pharmacological effects. In this project, the improving effects of isonicotinamide (INT) co-crystal and hydroxy propyl methyl cellulose (HPMC) or polyvinyl pyrrolidone (PVP) on the solubility, in vivo absorption, and anti-AAA effects of NGN were evaluated.

METHODS

In the current study, co-crystals of naringenin-isonicotinamide (NGN-INT) were prepared, and effects of PVP or HPMC on precipitation rate, supersaturation, and bioavailability of NGN were explored. In addition, with or without HPMC supply, the effects of NGN-INT co-crystal on anti-AAA efficacy of NGN were investigated on an elastase-induced AAA mouse model, and the results were compared with the efficacy of the NGN crude drug.

RESULTS

Our results demonstrate that NGN-INT formulation, compared to the NGN crude drug, enhanced the dissolution rate of NGN and significantly increased C_max and AUC_(0-∞) of NGN by 18 times and 1.97 times, respectively. Addition of PVP or HPMC in NGN-INT co-crystal further increased bioavailability of NGN in NGN-INT. The in vivo pharmacodynamic study showed that NGN-INT with HPMC significantly improved the inhibitory effects of NGN against AAA.

CONCLUSION

NGN-INT significantly improved the absorption and aortic protective effects of NGN. The supersaturation-prolonging effect of HPMC further enhanced bioavailability and anti-AAA effects of NGN-INT.

Study on the Inhibitory Effects of Naringenin-Loaded Nanostructured Lipid Carriers Against Nonalcoholic Fatty Liver Disease

Naringenin (NGN) can be used to inhibit the progression of nonalcoholic fatty liver disease (NAFLD) in mice, but its poor water solubility limits its applications. Nanostructured lipid carriers (NLCs) have recently attracted much attention in the field of nanodrug delivery systems because they increase the drug loading capacity and impressively enhance the solubility of indissolvable drugs. Herein, a thin-film dispersion method was used to prepare naringenin-loaded nanostructured lipid carriers (NGN-NLCs). These NGN-NLCs have a narrow size distribution of 171.9 ±2.0 nm, a high drug loading capacity of 23.7 ± 0.3%, a high encapsulation efficiency of 99.9 ± 0.0% and a drug release rate of 86.2 ± 0.4%. NGN- NLCs elevated the pharmacokinetic parameters (C_max and AUC_0→t) of NGN, accelerated NGN transepithelial transport in MDCK cells and intestinal absorption in the jejunum and ileum, and reduced hepatic lipid accumulation in an oleic acid (OA) plus lipopolysaccharide (LPS)-induced lipid deposition cell model in primary hepatocytes and in a methionine/choline deficient (MCD) diet-induced NAFLD mouse model. A detailed study of the mechanism showed that this NLC formulation elevated the drug release rate in simulated intestinal solutions in vitro, the transepithelial transport in MDCK cells, the oral absorption in mice and the ex vivo intestinal absorption of NGN. Thus, NGN-NLCs significantly enhanced the inhibitory effects of NGN on MCD diet induced mouse NAFLD.

The Evaluation of Drug Delivery Nanocarrier Development and Pharmacological Briefing for Metabolic-Associated Fatty Liver Disease (MAFLD): An Update

Current research indicates that the next silent epidemic will be linked to chronic liver diseases, specifically non-alcoholic fatty liver disease (NAFLD), which was renamed as metabolic-associated fatty liver disease (MAFLD) in 2020. Globally, MAFLD mortality is on the rise. The etiology of MAFLD is multifactorial and still incompletely understood, but includes the accumulation of intrahepatic lipids, alterations in energy metabolism, insulin resistance, and inflammatory processes. The available MAFLD treatment, therefore, relies on improving the patient's lifestyle and multidisciplinary pharmacotherapeutic options, whereas the option of surgery is useless without managing the comorbidities of the MAFLD. Nanotechnology is an emerging approach addressing MAFLD, where nanoformulations are suggested to improve the safety and physicochemical properties of conventional drugs/herbal medicines, physical, chemical, and physiological stability, and liver-targeting properties. A wide variety of liver nanosystems were constructed and delivered to the liver, only those that addressed the MAFLD were discussed in this review in terms of the nanocarrier classes, particle size, shape, zeta potential and offered dissolution rate(s), the suitable preparation method(s), excipients (with synergistic effects), and the suitable drug/compound for loading. The advantages and challenges of each nanocarrier and the focus on potential promising perspectives in the production of MAFLD nanomedicine were also highlighted.

Effect of enzymatic cross-linking of naringenin-loaded β-casein micelles on their release properties and fate in in vitro digestion

The microbial transglutaminase (mTG) was used to improve the stability of the naringenin-loaded β-casein micelles (CNMs). The formation of cross-linked CNMs was confirmed by SDS-PAGE electrophoresis, showing a decrease in monomeric β-CN levels with increasing crosslinking time. Dynamic light scattering (DLS) showed that after crosslinking the particle size distribution did not change upon dilution, suggesting occurrence of intra-crosslinking. Fluorescence spectroscopy and circular dichroism (CD) showed that crosslinking induced only minor changes in the structure. Finally, release of naringenin in buffer at pH 7.4 demonstrated a slower release from the cross-linked micelles compared to the untreated micelles. In addition, the cross-linked micelles exhibited a partial resistance to pepsin enzyme. We conclude that crosslinking with mTG is a suitable method to modulate naringenin release kinetics from β-CN micelles and improves the potential of these micelles as delivery systems targeted to the small intestine.

Naringenin Nano-Delivery Systems and Their Therapeutic Applications

Naringenin (NRG) is a polyphenolic phytochemical belonging to the class of flavanones and is widely distributed in citrus fruits and some other fruits such as bergamot, tomatoes, cocoa, and cherries. NRG presents several interesting pharmacological properties, such as anti-cancer, anti-oxidant, and anti-inflammatory activities. However, the therapeutic potential of NRG is hampered due to its hydrophobic nature, which leads to poor bioavailability. Here, we review a wide range of nanocarriers that have been used as delivery systems for NRG, including polymeric nanoparticles, micelles, liposomes, solid lipid nanoparticles (SLNs), nanostructured lipid carriers (NLCs), nanosuspensions, and nanoemulsions. These nanomedicine formulations of NRG have been applied as a potential treatment for several diseases, using a wide range of in vitro, ex vivo, and in vivo models and different routes of administration. From this review, it can be concluded that NRG is a potential therapeutic option for the treatment of various diseases such as cancer, neurological disorders, liver diseases, ocular disorders, inflammatory diseases, skin diseases, and diabetes when formulated in the appropriate nanocarriers.

Non-alcoholic fatty liver disease: An overview of risk factors, pathophysiological mechanisms, diagnostic procedures, and therapeutic interventions

Non-alcoholic fatty liver disease (NAFLD) is a disorder of excessive fat accumulation in the liver, known as steatosis, without alcohol overconsumption. NAFLD can either manifest as simple steatosis or steatohepatitis, known as non-alcoholic steatohepatitis (NASH), which is accompanied by inflammation and possibly fibrosis. Furthermore, NASH might progress to hepatocellular carcinoma. NAFLD and NASH prevalence is in a continuous state of growth, and by 2018, NAFLD became a devastating metabolic disease with a global pandemic prevalence. The pathophysiology of NAFLD and NASH is not fully elucidated, but is known to involve the complex interplay between different metabolic, environmental, and genetic factors. In addition, unhealthy dietary habits and pre-existing metabolic disturbances together with other risk factors predispose NAFLD development and progression from simple steatosis to steatohepatitis, and eventually to fibrosis. Despite their growing worldwide prevalence, to date, there is no FDA-approved treatment for NAFLD and NASH. Several off-label medications are used to target disease risk factors such as obesity and insulin resistance, and some medications are used for their hepatoprotective effects. Unfortunately, currently used medications are not sufficiently effective, and research is ongoing to investigate the beneficial effects of different drugs and phytochemicals in NASH. In this review article, we outline the different risk factors and pathophysiological mechanisms involved in NAFLD, diagnostic procedures, and currently used management techniques.

Formulation and intestinal absorption of naringenin loaded nanostructured lipid carrier and its inhibitory effects on nonalcoholic fatty liver disease

In this study, we prepared naringenin (NGN) loaded nanostructured lipid carrier (NGN-NLC) and investigated its characterizations, transepithelial transport, intestinal absorption and inhibitory effects on nonalcoholic fatty liver disease (NAFLD) induced by a methionine choline deficient (MCD) diet in mice. The NGN-NLC, prepared by a method of emulsion-evaporation plus low temperature-solidification, displayed high drug loading capacity of 22.5 ± 1.7%. Compared to the NGN crude drug, the NGN-NLC, at an equal NGN dose, improved NGN release rate by 3.5-fold and elevated NGN transepithelial transport and intestinal absorption through enhancing intracellular transport of clathrin pathway and escaping p-gp efflux; at an 8-fold lower NGN dose, showed comparable pharmacokinetic parameters, but elevated liver NGN distribution by 1.5-fold, reduced MCD diet-induced hepatic lipid deposition by 3-fold. These results suggest that the NLC formulation significantly increased the inhibitory effects of NGN on NAFLD because of the improved drug release rate, transepithelial transport and intestinal absorption, and the elevated oral bioavailability and liver NGN distribution.

A Comprehensive Systematic Review of the Effects of Naringenin, a Citrus-Derived Flavonoid, on Risk Factors for Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has become the most common cause of liver dysfunction worldwide. Recently, some natural compounds have attracted growing interest in the treatment of NAFLD. In this context, most attention has been paid to natural products derived from fruits, vegetables, and medicinal herbs. Naringenin, a natural flavanone, has been revealed to have pharmacological effects in the treatment of obesity and associated metabolic disorders such as NAFLD. The aim of this study was to examine the therapeutic effects of naringenin and its possible mechanisms of action in the management of NAFLD and related risk factors. The current systematic review was performed according to the guidelines of the 2015 PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) statements. We searched PubMed/Medline, Science Direct, Scopus, ProQuest, and Google Scholar databases up until February 2020. Of 1217 full-text articles assessed, 36 studies met the inclusion criteria. The evidence reviewed in the present study indicates that naringenin modulates several biological processes related to NAFLD including energy balance, lipid and glucose metabolism, inflammation, and oxidative stress by different mechanisms. Overall, the favorable effects of naringenin along with its more potency and efficacy, compared with other antioxidants, indicate that naringenin may be a promising therapeutic approach for the management of NAFLD and associated complications. However, due to the lack of clinical trials, future robust human randomized clinical trials that address the effects of naringenin on NAFLD and other liver-related diseases are crucial. Further careful human pharmacokinetic studies are also needed to establish dosage ranges, as well as addressing preliminary safety and tolerability of naringenin, before proceeding to larger-scale endpoint trials.

Novel self-nanomicellizing formulation based on Rebaudioside A: A potential nanoplatform for oral delivery of naringenin

In the study described here, we strove to develop an orally administered novel self-nanomicellizing formulation based on Rebaudioside A (RA) for delivering naringenin (NAR) with improved bioavailability and therapeutic efficacy. Our research found that RA and naringenin (NAR) could be formulated into self-assembling nanomicelles (RA-NAR) using a simple ethanol dissolution-evaporation method. We found that the RA-NAR self-assemblies comprised ultra-small micelles (5.234 ± 0.311 nm) in a uniform dispersion state (the polydispersity index was 0.243 ± 0.039) with a near-neutral surface charge (-[2.268 ± 0.729] mV). We also found that RA-NAR had a well-storage stability at 4 °C with light protection. In addition, we observed that RA-NAR exhibited enhanced apparent solubility, in-vitro permeability, and antioxidant activity. After we administered RA-NAR to rats orally, we observed an increase in area under the curve (AUC_0→t) to 19,500.82 ng/mL/h versus 9324.47 ng/mL/h observed with free NAR and an increase of maximum concentration (Cmax) to 27,326.10 ng/mL from the free-NAR Cmax level of 2549.04 ng/mL. The tissue distribution assessments further demonstrated that RA-NAR could effectively increase the NAR concentration in all tested intestinal segments. Our mouse model results showed as well that oral administration of RA-NAR could efficiently protect against small intestine injuries induced by indomethacin, and the mechanisms by inhibiting proinflammatory cytokines and oxidative stress were involved in its therapeutic effect. Taken together, these findings indicate that a self-nanomicellizing formulation based on RA has great potential as a novel oral nano-drug delivery system for NAR.

Naringenin attenuates non-alcoholic fatty liver disease by down-regulating the NLRP3/NF-κB pathway in mice

BACKGROUND AND PURPOSE

Naringenin, a flavonoid compound with strong anti-inflammatory activity, attenuated non-alcoholic fatty liver disease (NAFLD) induced by a methionine-choline deficient (MCD) diet in mice. However, the mechanisms underlying this suppression of inflammation and NAFLD remain unknown.

EXPERIMENTAL APPROACH

WT and NLRP3-/- mice were fed with MCD diet for 7 days to induce NAFLD and were given naringenin by gavage at the same time. in vitro experiments used HepG2 cells, primary hepatocytes, and Kupffer cells (KCs) stimulated by LPS or LPS plus oleic acid (OA).

KEY RESULTS

Treating WT mice with naringenin (100 mg·kg-1 ·day-1 ) attenuated hepatic lipid accumulation and inflammation in the livers of mice given the MCD diet. NLRP3-/- mice showed less hepatic lipid accumulation than WT mice, but naringenin did not ameliorate hepatic lipid accumulation further in NLRP3-/- mice. Treating the HepG2 cells with naringenin or NLRP3 inhibitor MCC950 reduced lipid accumulation. Naringenin inhibited activation of the NLRP3/NF-κB pathway stimulated by OA together with LPS. In KCs isolated from WT mice, naringenin inhibited NLRP3 expression. Naringenin also inhibited lipid deposition, NLRP3 and IL-1β expression in WT hepatocytes but was not effective in NLRP3-/- hepatocytes. After re-expressing NLRP3 in NLRP3-/- hepatocytes by adenovirus, the anti-lipid deposition effect of naringenin was restored.

CONCLUSION AND IMPLICATIONS

Naringenin prevented NAFLD via down-regulating the NLRP3/NF-κB signalling pathway both in KCs and in hepatocytes, thus attenuating inflammation in the mice livers.