Nobiletin-loaded micelles reduce ovariectomy-induced bone loss by suppressing osteoclastogenesis

Mechanism insights into the pleiotropic effects of nobiletin as a potential therapeutic agent on non-alcoholic fatty liver disease (NAFLD)

Non-alcoholic fatty liver disease (NAFLD) is one of the most common liver diseases and is emerging as one of the fastest-growing causes of liver-related deaths worldwide. It is necessary to find strategies to effectively prevent and treat NAFLD, as no definitive drug has been approved. Nobiletin (NOB) is the critical active ingredient of Chinese herbal medicines such as Citrus aurantium and Citri Reticulatae Pericarpium, which have anti-inflammatory, antioxidant, lipid regulating, and insulin resistance regulating effects. Numerous studies have demonstrated that NOB can prevent and treat the onset and progression of NAFLD. In this review, the mechanisms of NOB for treating NAFLD have been summarized, hoping to provide a basis for subsequent studies of NOB and to provide a research ground for the development of therapeutic drugs for NAFLD.

Preparation, optimization, and characterization of chrysin-loaded TPGS-b-PCL micelles and assessment of their cytotoxic potential in human liver cancer (Hep G2) cell lines

In total, nine TPGS-b-PCL copolymers were synthesized employing distinct TPGS analogues (TPGS 2000, 3500, and 5000). In these copolymers, the length of the PCL chain varied according to the TPGS to PCL molecular weight ratio (1:1, 1:2, and 1:3). The formulation optimization was done by optimizing the drug to polymer ratio, encapsulation efficiency, drug loading, micelle diameter, and polydispersity index (PDI). TPGS3500-b-PCL7000 copolymer (TPGS to PCL ratio 1:2) with drug to polymer ratio 1:30 showed the best percentage encapsulation (63.50 ± 0.45 %) and drug loading (2.05 ± 0.07). The optimal micelle (CHR-M) diameter and PDI were determined to be 94.57 ± 13.40 nm and 0.16 ± 0.02, respectively. CHR-M showed slow release when compared with alcoholic solution of chrysin. Approximately 70.70 ± 6.4 % drug was released in 72 h. The CHR-M demonstrated considerably greater absorption in Hep G2 cells, which confirmed the reliability of the micellar carrier. The MTT assay results showed that the IC50 values for CHR-M were much lower after 24 and 48 h when compared to free chrysin. Therefore, CHR-M may be a viable carrier for active chrysin targeting with improved anticancer potential. Also, it could be a better alternative for the currently available treatment of hepatocellular carcinoma.

Effects of 4′-Demethylnobiletin and 4′-Demethyltangeretin on Osteoclast Differentiation In Vitro and in a Mouse Model of Estrogen-Deficient Bone Resorption

Citrus nobiletin (NOB) and tangeretin (TAN) show protective effects against disease-related bone destruction. We achieved demethylation of NOB and TAN into 4′-demethylnobiletin (4′-DN) and 4′-demethyltangeretin (4′-DT) using enzyme-manufacturing methods. In this study, we examined the effects of 4′-DN and 4′-DT on in vitro osteoclast differentiation, and on in vivo osteoporotic bone loss in ovariectomized (OVX) mice. 4′-DN and 4′-DT clearly suppressed the osteoclast differentiation induced by interleukin IL-1 or RANKL treatment. 4′-DN and 4′-DT treatments resulted in higher inhibitory activity in osteoclasts in comparison to NOB or TAN treatments. RANKL induced the increased expression of its marker genes and the degradation of IκBα in osteoclasts, while these were perfectly attenuated by the treatment with 4′-MIX: a mixture of 4′-DN and 4′-DT. In an in silico docking analysis, 4′-DN and 4′-DT directly bound to the ATP-binding pocket of IKKβ for functional inhibition. Finally, the intraperitoneal administration of 4′-MIX significantly protected against bone loss in OVX mice. In conclusion, 4′-DN, 4′-DT and 4′-MIX inhibited the differentiation and function of bone-resorbing osteoclasts via suppression of the NF-κB pathway. Novel 4′-DN, 4′-DT and 4′-MIX are candidates for maintaining bone health, which may be applied in the prevention of metabolic bone diseases, such as osteoporosis.

Bioactivity, Molecular Mechanism, and Targeted Delivery of Flavonoids for Bone Loss

Skeletal disabilities are a prominent burden on the present population with an increasing life span. Advances in osteopathy have provided various medical support for bone-related diseases, including pharmacological and prosthesis interventions. However, therapeutics and post-surgery complications are often reported due to side effects associated with modern-day therapies. Thus, therapies utilizing natural means with fewer toxic or other side effects are the key to acceptable interventions. Flavonoids constitute a class of bioactive compounds found in dietary supplements, and their pharmacological attributes have been well appreciated. Recently, flavonoids' role is gaining renowned interest for its effect on bone remodeling. A wide range of flavonoids has been found to play a pivotal role in the major bone signaling pathways, such as wingless-related integration site (Wnt)/β-catenin, bone morphogenetic protein (BMP)/transforming growth factor (TGF)-β, mitogen-activated protein kinase (MAPK), etc. However, the reduced bioavailability and the absorption of flavonoids are the major limitations inhibiting their use against bone-related complications. Recent utilization of nanotechnological approaches and other delivery methods (biomaterial scaffolds, micelles) to target and control release can enhance the absorption and bioavailability of flavonoids. Thus, we have tried to recapitulate the understanding of the role of flavonoids in regulating signaling mechanisms affecting bone remodeling and various delivery methods utilized to enhance their therapeutical potential in treating bone loss.

Application of nanomaterials in the treatment of intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a non-traumatic hemorrhage caused by the rupture of blood vessels in the brain parenchyma, with an acute mortality rate of 30%‒40%. Currently, available treatment options that include surgery are not promising, and new approaches are urgently needed. Nanotechnology offers new prospects in ICH because of its unique benefits. In this review, we summarize the applications of various nanomaterials in ICH. Nanomaterials not only enhance the therapeutic effects of drugs as delivery carriers but also contribute to several facets after ICH such as repressing detrimental neuroinflammation, resisting oxidative stress, reducing cell death, and improving functional deficits.

Alendronate modified mPEG-PLGA nano-micelle drug delivery system loaded with astragaloside has anti-osteoporotic effect in rats

Astragaloside (AS) has an anti-osteoporotic effect, but its poor water solubility and low bioavailability limit its application. In this study, a novel nano-carrier with bone targeting was prepared by modifying mPEG-PLGA with alendronate (AL) before incorporation into astragaloside nano-micelles (AS-AL-mPEG-PLGA) to enhance the oral bioavailability, bone targeting and anti-osteoporosis effect of AS. The release behavior of AS-AL-mPEG-PLGA in vitro was investigated via dialysis. The pharmacokinetics of AS-AL-mPEG-PLGA was studied in Sprague-Dawley (SD) rats. The cytotoxicity of AS-AL-mPEG-PLGA in vitro (via MTT method), coupled with bone targeting ability in vitro and in vivo were evaluated. The therapeutic effects of free AS and AS-AL-mPEG-PLGA (ELISA, micro-CT, H&E staining) were compared in osteoporotic rats. AS-AL-mPEG-PLGA with smaller particle size (45.3 ± 3.8 nm) and high absolute zeta potential (−23.02 ± 0.51 mV) were successfully prepared, wherein it demonstrated higher entrapment efficiency (96.16 ± 0.18%), a significant sustained-release effect for 96 h and acceptable safety within 10–200 μg/mL. AS-AL-mPEG-PLGA could enhance the hydroxyapatite affinity and bone tissue concentration of AS. The relative bioavailability of AS-AL-mPEG-PLGA was 233.90% compared with free AS. In addition, the effect of AS in reducing serum levels of bone metabolism-related indicators, restoring the bone microarchitecture and improving bone injury could be enhanced by AS-AL-mPEG-PLGA. AS-AL-mPEG-PLGA with small particle size, good stability, remarkable sustained-release effect, safety and bone targeting was successfully constructed in this experiment to potentially improve the oral bioavailability and anti-osteoporosis effect of AS. Thus, AS-AL-mPEG-PLGA may be a promising strategy to prevent and treat osteoporosis.

Nobiletin, a NF-κB signaling antagonist, promotes BMP-induced bone formation

The NF-κB family of transcription factors plays an important role in skeletal development and bone homeostasis. In osteoblast cells, NF-κB signaling has been shown to suppress survival, proliferation, and differentiation. Furthermore, pharmacological suppression of NF-κB enhances osteoblast differentiation and bone formation. Thus, NF-κB antagonists are promising candidates as anabolic agents for enhancing bone mass. In this study, we describe the mechanism by which nobiletin, an inhibitor of NF-κB activity, regulates osteoblast differentiation and mineralization. We found that in MC3T3-E1 osteoblast cells, nobiletin inhibited a TNF-α responsive NF-κB luciferase reporter and also decreased the induction of classical NF-κB target genes by TNF-α. Consistent with this, nobiletin prevented TNF-α -mediated suppression of osteogenesis and potently enhanced the differentiation and mineralization of MC3T3-E1 cells. Likewise, in an in vivo BMP2-induced ectopic bone formation assay, nobiletin markedly enhanced ossicle bone volume. Western blotting and SMAD-responsive luciferase assays also demonstrated that NF-κB suppression of BMP signaling could be inhibited by nobiletin. Thus, our data suggest that mechanistically, nobiletin prevents the endogenous repression of BMP signaling by TNF-α, thereby enhancing osteoblast activity. In conclusion, nobiletin is a novel NF-κB antagonist that may be a useful anabolic agent for bone formation.

Poly (Thioether-Polyesters) Micelles Encapsulation Induces ROS-Triggered Targeted Release of Tangeretin

Tangeretin (Tan) possesses great anti-oxidation and anti-inflammation bioactivities; however, it is accompanied by poor water solubility, which leads to inefficient cellular internalization. To address this issue, a reactive oxygen species (ROS)-triggered poly (thioether-polyesters) micelle (PDHP, PEG-DTT) was designed and prepared via self-assembly, which consisted of poly (thioether-polyesters) as the hydrophilic shell, and the drug Tan as the hydrophobic inner core. The micelles (Tan@ PDHP), with a 63.15% loading efficiency of Tan, showed negligible cytotoxicity, high stability in phosphate-buffered saline buffer (pH  =  7.4), and continuous release of Tan with the stimulation of H2O2. In addition, this Tan loading micelle was more efficient in responding to the formation of ROS in the lipopolysaccharide-stimulated RAW264.7 cells compared to that of the free Tan. In short, the strategy of encapsulating the low solubility Tan in ROS-triggered poly (thioether-polyesters) micelles provides an effective assay of enhancing Tan's antioxidative activity.

Network Pharmacology and Molecular Docking Elucidate the Pharmacological Mechanism of the OSTEOWONDER Capsule for Treating Osteoporosis

Background: Osteoporosis (OP) is a serious and common bone metabolic disease with bone mass loss and bone microarchitectural deterioration. The OSTEOWONDER capsule is clinically used to treat OP. However, the potential regulatory mechanism of the OSTEOWONDER capsule in treatment of OP remains largely unknown.

Methods: The bioactive compounds of herbs and their targets were identified using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) database. The speculative targets of OP were screened out based on GeneCards, DisGeNET, and Online Mendelian Inheritance in Man (OMIM) databases. The gene modules and hub genes of OP were identified using a weighted gene co-expression network analysis (WGCNA). Then, an herb-compound-target network was constructed based on the above analyses. The biological function of targets was subsequently investigated, and a protein–protein interaction (PPI) network was constructed to identify hub targets of OP. Finally, molecular docking was performed to explore the interaction between compounds and targets.

Results: A total of 148 compounds of eight herbs and the corresponding 273 targets were identified based on the TCMSP database. A total of 4,929 targets of OP were obtained based on GeneCards, DisGeNET, and OMIM databases. In addition, six gene modules and 4,235 hub genes of OP were screened out based on WGCNA. Generally, an herb-compound-target network, including eight herbs, 84 compounds, and 58 targets, was constructed to investigate the therapeutic mechanism of the OSTEOWONDER capsule for OP. The biofunction analysis indicated 58 targets mainly associated with the bone metabolism, stimulation response, and immune response. EGFR, HIF1A, MAPK8, IL6, and PPARG were identified as the hub therapeutic targets in OP. Moreover, the interaction between EGFR, HIF1A, MAPK8, IL6, PPARG, and the corresponding compounds (quercetin and nobiletin) was analyzed using molecular docking.

Conclusion: Our finding discovered the possible therapeutic mechanisms of the OSTEOWONDER capsule and supplied the potential therapeutic targets for OP.

The Application of Citrus folium in Breast Cancer and the Mechanism of Its Main Component Nobiletin: A Systematic Review

Citrus folium and its main ingredient nobiletin (NOB) have received widespread attention in recent years due to their antitumor effects. The antitumor effect of Citrus folium is related to the traditional use, mainly in its Chinese medicinal properties of soothing the liver and promoting qi, resolving phlegm, and dispelling stagnation. Some studies have proved that Citrus folium and NOB are more effective for triple-negative breast cancer (TNBC), which is related to the syndrome of stagnation of liver qi. From the perspective of modern biomedical research, NOB has anticancer effects. Its potential molecular mechanisms include inhibition of the cell cycle, induction of apoptosis, and inhibition of angiogenesis, invasion, and migration. Citrus folium and NOB can also reduce the side effects of chemotherapy drugs and reverse multidrug resistance (MDR). However, more research studies are needed to clarify the underlying mechanisms. The modern evidence of Citrus folium and NOB in breast cancer treatment has a strong connection with the traditional concepts and laws of applying Citrus folium in Chinese medicine (CM). As a low-toxic anticancer drug candidate, NOB and its structural changes, Citrus folium, and compound prescriptions will attract scientists to use advanced technologies such as genomics, proteomics, and metabolomics to study its potential anticancer effects and mechanisms. On the contrary, there are relatively few studies on the anticancer effects of Citrus folium and NOB in vivo. The clinical application of Citrus folium and NOB as new cancer treatment drugs requires in vivo verification and further anticancer mechanism research. This review aims to provide reference for the treatment of breast cancer by Chinese medicine.

Osteoporosis and Its Nanotechnology-Based Advanced Treatment-An Overview

Human Immunodeficiency Virus (HIV) is a global pandemic that has contributed to the burden of disease, and the synergistic interaction between Herpes Simplex Virus (HSV) and HIV has assisted further in the spread of the HIV disease. Moreover, several chemotherapeutic treatment options from antiviral monotherapy to highly active antiretroviral therapy (HAART) have been adopted to manage the infection; however, HIV has developed new mechanisms against these active pharmaceutical agents (APAs), limiting the effect of the drugs. In this article, we reviewed different nanoparticles and their antiviral potency against HSV and HIV infection as well as the effect of drug encapsulated nanoparticles using different drug delivery systems as they palliate to some flaws or deficiencies that the stand-alone drugs present. Drug encapsulated nanoparticles show better treatment outcomes of HSV and HIV infection. The nanoparticles can transverse the anatomic privilege sites to exert their therapeutic effect, and a prolonged and higher dose of the encapsulated therapeutic agent can ease the dosage frequency, thus palliating low drug compliance which the stand-alone drugs fail to perform. Therefore, it is clear that nanoparticles prevent antiviral drug resistance by maintaining sustained drug release over an extended period, improving the therapeutic effect of the entrapped drug.

Rosuvastatin Nanomicelles Target Neuroinflammation and Improve Neurological Deficit in a Mouse Model of Intracerebral Hemorrhage

Background

Intracerebral hemorrhage (ICH), a devastating subtype of stroke, has a poor prognosis. However, there is no effective therapy currently available due to its complex pathological progression, in which neuroinflammation plays a pivotal role in secondary brain injury. In this work, the use of statin-loaded nanomicelles to target the neuroinflammation and improve the efficacy was studied in a mouse model of ICH.

Methods

Rosuvastatin-loaded nanomicelles were prepared by a co-solvent evaporation method using polyethylene glycol-poly(ε-caprolactone) (PEG-PCL) copolymer as a carrier. The prepared nanomicelles were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS), and then in vitro and in vivo studies were performed.

Results

TEM shows that the nanomicelles are spherical with a diameter of about 19.41 nm, and DLS shows that the size, zeta potential, and polymer dispersity index of the nanomicelles were 23.37 nm, −19.2 mV, and 0.221, respectively. The drug loading content is 8.28%. The in vivo study showed that the nanomicelles significantly reduced neuron degeneration, inhibited the inflammatory cell infiltration, reduced the brain edema, and improved neurological deficit. Furthermore, it was observed that the nanomicelles promoted the polarization of microglia/macrophages to M2 phenotype, and also the expression of the proinflammatory cytokines, such as IL-1β and TNF-α, was significantly down-regulated, while the expression of the anti-inflammatory cytokine IL-10 was significantly up-regulated. The related mechanism was proposed and discussed.

Conclusion

The nanomicelles treatment suppressed the neuroinflammation that might contribute to the promoted nerve functional recovery of the ICH mouse, making it potential to be applied in clinic.

Nano-Based Biomaterials as Drug Delivery Systems Against Osteoporosis: A Systematic Review of Preclinical and Clinical Evidence

Osteoporosis (OP) is one of the most significant causes of morbidity, particularly in post-menopausal women and older men. Despite its remarkable occurrence, the search for an effective treatment is still an open challenge. Here, we systematically reviewed the preclinical and clinical progress in the development of nano-based materials as drug delivery systems against OP, considering the effects on bone healing and regeneration, the more promising composition and manufacturing methods, and the more hopeful drugs and delivery methods. The results showed that almost all the innovative nano-based delivery systems developed in the last ten years have been assessed by preclinical investigations and are still in the preliminary/early research stages. Our search strategy retrieved only one non-randomized controlled trial (RCT) on oligosaccharide nanomedicine of alginate sodium used for degenerative lumbar diseases in OP patients. Further investigations are mandatory for assessing the clinical translation and commercial purposes of these materials. To date, the main limits for the clinical translation of nano-based materials as drug delivery systems against OP are probably due to the low reproducibility of the manufacturing processes, whose specificity and complexity relies on an adequate chemical, structural, and biomechanical characterization, as the necessary prerequisite before assessing the efficacy of a given treatment or process. Finally, an unsatisfactory drug-loading capacity, an uncontrollable release kinetic, and a low delivery efficiency also limit the clinical application.

Citrus Flavonoids as Promising Phytochemicals Targeting Diabetes and Related Complications: A Systematic Review of In Vitro and In Vivo Studies

The consumption of plant-based food is important for health promotion, especially concerning the prevention and management of chronic diseases. Flavonoids are the main bioactive compounds in citrus fruits, with multiple beneficial effects, especially antidiabetic effects. We systematically review the potential antidiabetic action and molecular mechanisms of citrus flavonoids based on in vitro and in vivo studies. A search of the PubMed, EMBASE, Scopus, and Web of Science Core Collection databases for articles published since 2010 was carried out using the keywords citrus, flavonoid, and diabetes. All articles identified were analyzed, and data were extracted using a standardized form. The search identified 38 articles, which reported that 19 citrus flavonoids, including 8-prenylnaringenin, cosmosiin, didymin, diosmin, hesperetin, hesperidin, isosiennsetin, naringenin, naringin, neohesperidin, nobiletin, poncirin, quercetin, rhoifolin, rutin, sineesytin, sudachitin, tangeretin, and xanthohumol, have antidiabetic potential. These flavonoids regulated biomarkers of glycemic control, lipid profiles, renal function, hepatic enzymes, and antioxidant enzymes, and modulated signaling pathways related to glucose uptake and insulin sensitivity that are involved in the pathogenesis of diabetes and its related complications. Citrus flavonoids, therefore, are promising antidiabetic candidates, while their antidiabetic effects remain to be verified in forthcoming human studies.

Nobiletin as a Molecule for Formulation Development: An Overview of Advanced Formulation and Nanotechnology-Based Strategies of Nobiletin

Approximately 40% of compounds in clinical drug development suffer from solubility and bioavailability challenges. Evidence from literature demonstrates the growing interest to utilize flavonoids as potential compounds owing to their widespread therapeutic utility in various ailments. Nobiletin (NOB), one such dietary polymethoxylated flavonoid found in citrus fruits, has multiple pharmacological effects such as antioxidant, anti-microbial, anti-cancer, and anti-inflammatory. It is useful in cancer, inflammatory bowel diseases, atherosclerosis, obesity, and Alzheimer's disease. Although preclinical studies demonstrate the therapeutic utility of NOB, it suffers from serious biopharmaceutical limitations such as low aqueous solubility (below 1 μg/ml), poor permeability across biological barriers, and low bioavailability. To overcome these biopharmaceutical challenges associated with NOB, the use of advanced formulations and nanotechnology-based strategies appears to be a promising approach to potentiate its therapeutic action. Multiple reviews cover the various therapeutic benefits of NOB in various diseases; however, there is an absence of a comprehensive review that focuses on the formulation development strategies of NOB. The purpose of this review is to provide a concise perspective on NOB as a candidate molecule for formulation development. The manuscript covers various aspects related to NOB, such as its chemistry, physicochemical properties, and pharmacological effects. This is also a thorough review of various formulation development strategies with advances made in the past years to improve the solubility, bioavailability, and therapeutic efficacy of NOB. The review also contains information related to toxicity and patents involving NOB and its formulation.

Nobiletin in Cancer Therapy: How This Plant Derived-Natural Compound Targets Various Oncogene and Onco-Suppressor Pathways

Cancer therapy is a growing field, and annually, a high number of research is performed to develop novel antitumor drugs. Attempts to find new antitumor drugs continue, since cancer cells are able to acquire resistance to conventional drugs. Natural chemicals can be considered as promising candidates in the field of cancer therapy due to their multiple-targeting capability. The nobiletin (NOB) is a ubiquitous flavone isolated from Citrus fruits. The NOB has a variety of pharmacological activities, such as antidiabetes, antioxidant, anti-inflammatory, hepatoprotective, and neuroprotective. Among them, the antitumor activity of NOB has been under attention over recent years. In this review, we comprehensively describe the efficacy of NOB in cancer therapy. NOB induces apoptosis and cell cycle arrest in cancer cells. It can suppress migration and invasion of cancer cells via the inhibition of epithelial-to-mesenchymal transition (EMT) and EMT-related factors such as TGF-β, ZEB, Slug, and Snail. Besides, NOB inhibits oncogene factors such as STAT3, NF-κB, Akt, PI3K, Wnt, and so on. Noteworthy, onco-suppressor factors such as microRNA-7 and -200b undergo upregulation by NOB in cancer therapy. These onco-suppressor and oncogene pathways and mechanisms are discussed in this review.