Curcumin loaded NLC induces histone hypoacetylation in the CNS after intraperitoneal administration in mice

Nanosuspension encapsulated chitosan-pectin microbeads as a novel delivery platform for enhancing oral bioavailability

The current study aimed to overcome the poor solubility and colon-specific delivery of curcumin (CUR) by formulating a curcumin nanosuspension (CUR-NS) using the antisolvent precipitation method. Freeze-dried CUR-NS was encapsulated into microbeads (CUR-NS-MB) by the ionotropic gelation method using zinc chloride (as a cross-linking agent) with the help of rate-controlling polymers, pectin, and chitosan. Furthermore, cellulose acetate phthalate (CAP) is incorporated as an enteric polymer to protect against acidic medium degradation. Particle size, surface morphology, interaction studies, and entrapment studies were performed to optimize CUR-NSs. Nanosuspensions stabilized with hydroxypropyl methylcellulose (HPMC E-15; 1 % w/v) showed an average particle size of 193.5 ± 4.31 nm and a polydispersity index (PDI) of 0.261 ± 0.020. The optimized microbeads (CUR-NS-MB) showed 89.45 ± 3.11 % entrapment efficiency with a drug loading of 14.54 ± 1.02 %. The optimized formulation (CUR-NS-MB) showed colon-specific in vitro drug release bypassing acid pH degradation. In animal studies, a 2.5-fold increase in Cmax and a 4.4-fold increase in AUC048h were observed with CUR-NS-MB, which was more significant than that of plain CUR. Therefore, the developed CUR-NS-MB has the potential to be used as a colon-specific delivery system.

Lipid Nanoparticles: An Effective Tool to Improve the Bioavailability of Nutraceuticals

Nano-range bioactive colloidal carrier systems are envisaged to overcome the challenges associated with treatments of numerous diseases. Lipid nanoparticles (LNPs), one of the extensively investigated drug delivery systems, not only improve pharmacokinetic parameters, transportation, and chemical stability of encapsulated compounds but also provide efficient targeting and reduce the risk of toxicity. Over the last decades, nature-derived polyphenols, vitamins, antioxidants, dietary supplements, and herbs have received more attention due to their remarkable biological and pharmacological health and medical benefits. However, their poor aqueous solubility, compromised stability, insufficient absorption, and accelerated elimination impede research in the nutraceutical sector. Owing to the possibilities offered by various LNPs, their ability to accommodate both hydrophilic and hydrophobic molecules and the availability of various preparation methods suitable for sensitive molecules, loading natural fragile molecules into LNPs offers a promising solution. The primary objective of this work is to explore the synergy between nature and nanotechnology, encompassing a wide range of research aimed at encapsulating natural therapeutic molecules within LNPs.

In vivo evaluation of nanostructured lipid carrier systems (NLCs) in mice bearing prostate cancer tumours

Nanostructure lipid carriers (NLCs) were developed for the delivery of curmumin (CRN), a potent anticancer agent with low bioavailability, for the treatment of prostate cancer. NLCs prepared using high pressure homogenization (HPH) with around 150 nm particle size, - 40 V ζ-potential and excellent long-term stability. Cellular uptake of CRN-SLN showed nanoparticle localization in the cytoplasm around the nucleus. CRN-NLCs were assessed using flow cytometry and found to cause early and late apoptotic events at 100 μg/ml CRN concentrations. CRN-NLC nanoparticles were administrated to nude mice with LNCaP prostate cancer xenografts and demonstrated substantial tumour volume suppression (40%) with no weight loss compared to pure CRN (ethanolic solution). Overall, NLCs were proved a suitable carrier for passive drug delivery and cancer treatment.

Therapeutic and Preventive Effects of Piperine and its Combination with Curcumin as a Bioenhancer Against Aluminum-Induced Damage in the Astrocyte Cells

Recently, studies conducted with astrocyte cells have drawn attention to neurodegeneration pathologies caused by aluminum exposure. In particular, investigating the potential of herbal therapeutic agents to prevent this effect of aluminum has gained importance. The purpose of this study was to investigate the therapeutic and preventive effects of piperine, curcumin, and the combination of these compounds on reactive primary astrocyte cells. In order to examine the preventive effect, certain concentrations of compounds were applied to the cells before the aluminum application, and to be able to determine the therapeutic effect, the compounds were examined after the aluminum application. The efficacy of the compounds was analyzed in terms of cell viability, apoptosis, necrosis, and cytokine release. In conclusion, the results of the study showed that the use of different concentrations of piperine, curcumin, and their combination had significantly higher % cell viability on aluminum-induced damage in astrocyte cells compared to the damaged control group. In addition, a decrease in the number of apoptotic and necrotic cells was observed in the same groups, which indicated that piperine increased curcumin activity. The decrease in the amount of IL-6 and TGF-β cytokines also supported that piperine increased the effectiveness of curcumin. Considering all these results, it can be said that in terms of aluminum damage in astrocyte cells, the bioavailability-enhancing property of piperine on curcumin was shown for the first time in the literature. In line with these results, it is inevitable to carry out further studies.

Solid lipid nanoparticles loaded with curcumin: development and in vitro toxicity against CT26 cells

Aim: To develop a new curcumin carrier consisting of murumuru butter nanoparticles (SLN-Cs). Methods: A phase-inversion temperature method was used to produce SLN-Cs. The interaction of SLN-Cs with murine colon adenocarcinoma (CT26) cells in vitro was analyzed by confocal microscopy. Results: Stable SLN-Cs with a high curcumin-loading capacity were obtained. The SLN-Cs were more toxic to CT26 than free curcumin. Fluorescence microscopy images showed the SLN-Cs to be taken up by CT26 cells in vitro. Conclusion: These results indicate that SLN-Cs are suitable carriers of curcumin in aqueous media.

p300/Sp1-Mediated High Expression of p16 Promotes Endothelial Progenitor Cell Senescence Leading to the Occurrence of Chronic Obstructive Pulmonary Disease

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a common chronic disease and develops rapidly into a grave public health problem worldwide. However, what exactly causes the occurrence of COPD remains largely unclear. Here, we are trying to explore whether the high expression of p16 mediated by p300/Sp1 can cause chronic obstructive pulmonary disease through promoting the senescence of endothelial progenitor cells (EPCs).

METHODS

Peripheral blood EPCs were isolated from nonsmoking non-COPD, smoking non-COPD, and smoking COPD patients. The expressions of p16, p300, and senescence-related genes were detected by RT-PCR and Western Blot. Then, we knocked down or overexpressed Sp1 and p300 and used the ChIP assay to detect the histone H4 acetylation level in the promoter region of p16, CCK8 to detect cell proliferation, flow cytometry to detect the cell cycle, and β-galactosidase staining to count the proportion of senescent cells.

RESULTS

The high expression of p16 was found in peripheral blood EPCs of COPD patients; the cigarette smoke extract (CSE) led to the increase of p16. The high expression of p16 in EPCs promoted cell cycle arrest and apoptosis. The CSE-mediated high expression of p16 promoted cell senescence. The expression of p300 was increased in peripheral blood EPCs of COPD patients. Moreover, p300/Sp1 enhanced the histone H4 acetylation level in the promoter region of p16, thereby mediating the senescence of EPCs. And knockdown of p300/Sp1 could rescue CSE-mediated cell senescence.

CONCLUSION

p300/Sp1 enhanced the histone H4 acetylation level in the p16 promoter region to mediate the senescence of EPCs.

Different Microfluidic Environments for In Vitro Testing of Lipid Nanoparticles against Osteosarcoma

The use of lipid nanoparticles as biodegradable shells for controlled drug delivery shows promise as a more effective and targeted tumor treatment than traditional treatment methods. Although the combination of target therapy with nanotechnology created new hope for cancer treatment, methodological issues during in vitro validation of nanovehicles slowed their application. In the current work, the effect of methotrexate (MTX) encapsulated in different matrices was evaluated in a dynamic microfluidic platform. Effects on the viability of osteosarcoma cells in the presence of recirculation of cell media, free MTX and two types of blank and drug-containing nanoparticles were successfully assessed in different tumor-mimicking microenvironments. Encapsulated MTX was more effective than the equal dose free drug treatment, as cell death significantly increased under the recirculation of both types of drug-loaded nanoparticles in all concentrations. In fact, MTX-nanoparticles reduced cell population 50 times more than the free drug when 150-µM drug dose was recirculated. Moreover, when compared to the equivalent free drug dose recirculation, cell number was reduced 60 and 100 points more under recirculation of each nanoparticle with a 15-µM drug concentration. Thus, the results obtained with the microfluidic model present MTX-lipid nanoparticles as a promising and more effective therapy for pediatric osteosarcoma treatment than current treatment options.

Curcumin Loaded Polymeric vs. Lipid Nanoparticles: Antioxidant Effect on Normal and Hypoxic Olfactory Ensheathing Cells

Background: Curcumin (Cur) shows anti-inflammatory and antioxidant effects on central nervous system diseases. The aim of this study was to develop Cur-loaded polymeric and lipid nanoparticles for intranasal delivery to enhance its stability and increase antioxidant effect on olfactory ensheathing cells (OECs). Methods: The nanosuspensions were subjected to physico-chemical and technological evaluation through photon correlation spectroscopy (PCS), differential scanning calorimetry (DSC) and UV-spectrophotometry. The cytotoxicity studies of nanosuspensions were carried out on OECs. A viability test was performed after 24 h of exposure of OECs to unloaded and curcumin-loaded nanosuspensions. The potential protective effect of Cur was assessed on hypoxic OECs cells. Uptake studies were performed on the same cell cultures. Thermal analysis was performed to evaluate potential interaction of Cur with a 1,2-Dimyristoyl-sn-glycero-3-phosphocholine (DMPC) biomembrane model. Results: PCS analysis indicated that lipid and polymeric nanosuspensions showed a mean size of 127.10 and 338.20 nm, respectively, high homogeneity and negative zeta potential. Incorporation of Cur into both nanocarriers increased drug stability up to 135 days in cryoprotected freeze-dried nanosuspensions. Cell viability was improved when hypoxic OECs were treated with Cur-loaded polymeric and lipid nanosuspensions compared with the control. Conclusions: Both nanocarriers could improve the stability of Cur as demonstrated by technological studies. Biological studies revealed that both nanocarriers could be used to deliver Cur by intranasal administration for brain targeting.

Polychemotherapy with Curcumin and Doxorubicin via Biological Nanoplatforms: Enhancing Antitumor Activity

Doxorubicin (DOX) is a well-known chemotherapeutic agent extensively applied in the field of cancer therapy. However, similar to other chemotherapeutic agents such as cisplatin, paclitaxel, docetaxel, etoposide and oxaliplatin, cancer cells are able to obtain chemoresistance that limits DOX efficacy. In respect to dose-dependent side effect of DOX, enhancing its dosage is not recommended for effective cancer chemotherapy. Therefore, different strategies have been considered for reversing DOX resistance and diminishing its side effects. Phytochemical are potential candidates in this case due to their great pharmacological activities. Curcumin is a potential antitumor phytochemical isolated from Curcuma longa with capacity of suppressing cancer metastasis and proliferation and affecting molecular pathways. Experiments have demonstrated the potential of curcumin for inhibiting chemoresistance by downregulating oncogene pathways such as MMP-2, TGF-β, EMT, PI3K/Akt, NF-κB and AP-1. Furthermore, coadministration of curcumin and DOX potentiates apoptosis induction in cancer cells. In light of this, nanoplatforms have been employed for codelivery of curcumin and DOX. This results in promoting the bioavailability and internalization of the aforementioned active compounds in cancer cells and, consequently, enhancing their antitumor activity. Noteworthy, curcumin has been applied for reducing adverse effects of DOX on normal cells and tissues via reducing inflammation, oxidative stress and apoptosis. The current review highlights the anticancer mechanism, side effects and codelivery of curcumin and DOX via nanovehicles.

Solid Lipid Nanoparticles as Carriers of Natural Phenolic Compounds

Phenolic compounds are one of the most widespread classes of compounds in nature, with several beneficial biological effects being associated with their anti-oxidant and anti-carcinogenic activities. Their application in the prevention or treatment of numerous chronic diseases have been studied, but a major drawback is still the low bioavailability of these compounds, as well as their instability towards pH, temperature, and light in some cases. Nanotechnology has emerged as an alternative to overcome these limitations, and the use of lipidic encapsulation systems is a promising technique to achieve an efficient drug delivery, protecting molecules from external factors and improving their bioavailability. In this review, solid lipid nanoparticles and nanostructured lipid carriers are highlighted as an important tool for the improvement of the bioavailability and stability of natural phenolic compounds, including their preparation methods and functionalization approaches and the discussion of several applications for putative use in cosmetic and pharmacologic products.

Alzheimer's disease: natural products as inhibitors of neuroinflammation

Alzheimer’s disease (AD) is the most common form of dementia and affects 44 million people worldwide. New emerging evidence from pre-clinical and clinical investigations shows that neuroinflammation is a major pathological component of AD suggesting that anti-inflammatory strategies are important in delaying the onset or slowing the progression of the disease. However, efforts to employ current anti-inflammatory agents in AD clinical trials have produced limited success. Consequently, there is a need to explore anti-inflammatory natural products, which target neuroinflammatory pathways relevant to AD pathogenesis. This review summarises important druggable molecular targets of neuroinflammation and presents classes of anti-neuroinflammatory natural products with potentials for preventing and reducing symptoms of AD.

Curcumin Diglutaric Acid, a Prodrug of Curcumin Reduces Pain Hypersensitivity in Chronic Constriction Injury of Sciatic Nerve Induced-Neuropathy in Mice

The drug treatment for neuropathic pain remains a challenge due to poor efficacy and patient satisfaction. Curcumin has been reported to alleviate neuropathic pain, but its clinical application is hindered by its low solubility and poor oral bioavailability. Curcumin diglutaric acid (CurDG) is a curcumin prodrug with improved water solubility and in vivo antinociceptive effects. In this study, we investigated the anti-inflammatory mechanisms underlying the analgesic effect of CurDG in the chronic constriction injury (CCI)-induced neuropathy mouse model. Repeated oral administration of CurDG at a low dose equivalent to 25 mg/kg/day produced a significant analgesic effect in this model, both anti-allodynic activity and anti-hyperalgesic activity appearing at day 3 and persisting until day 14 post-CCI surgery (p < 0.001) while having no significant effect on the motor performance. Moreover, the repeated administration of CurDG diminished the increased levels of the pro-inflammatory cytokines: TNF-α and IL-6 in the sciatic nerve and the spinal cord at the lowest tested dose (equimolar to 25 mg/kg curcumin). This study provided pre-clinical evidence to substantiate the potential of pursuing the development of CurDG as an analgesic agent for the treatment of neuropathic pain.

In vitro and in vivo antimicrobial activity of sodium colistimethate and amikacin-loaded nanostructured lipid carriers (NLC)

Sodium colistimethate (SCM) and amikacin (AMK) are among the few antibiotics effective against resistant P. aeruginosa, K. pneumoniae and A. baumannii; however, their toxicity severely limits their use. Enclosing antibiotics into nanostructured lipid carriers (NLC) might decrease drug toxicity and improve antibiotic disposition. In this work, SCM or AMK was loaded into different NLC formulations, through high pressure homogenization, and their in vitro and in vivo effectiveness was analyzed. The encapsulation process did not reduce drug effectiveness since in vitro SCM-NLC and AMK-NLC drug activity was equal to that of the free drugs. As cryoprotectant, trehalose showed better properties than dextran. Instead, positive chitosan coating was discarded due to its limited cost-efficiency. Finally, the in vivo study in acute pneumonia model revealed that intraperitoneal administration was superior to the intramuscular route and confirmed that (-) SCM-NLC with trehalose, was the most suitable formulation against an extensively drug-resistant A. baumannii strain.

Optimization of Curcumin Nanocrystals as Promising Strategy for Nose-to-Brain Delivery Application

Intranasal (IN) drug delivery is recognized to be an innovative strategy to deliver drugs to the Central Nervous System. One of the main limitations of IN dosing is the low volume of drug that can be administered. Accordingly, two requirements are necessary: the drug should be active at a low dosage, and the drug solubility in water must be high enough to accommodate the required dose. Drug nanocrystals may overcome these limitations; thus, curcumin was selected as a model drug to prepare nanocrystals for potential IN administration. With this aim, we designed curcumin nanocrystals (NCs) by using Box Behnken design. A total of 51 formulations were prepared by the sonoprecipitation method. Once we assessed the influence of the independent variables on nanocrystals' mean diameter, the formulation was optimized based on the desirability function. The optimized formulation was characterized from a physico-chemical point of view to evaluate the mean size, zeta potential, polidispersity index, pH, osmolarity, morphology, thermotropic behavior and the degree of crystallinity. Finally, the cellular uptake of curcumin and curcumin NCs was evaluated on Olfactory Ensheathing Cells (OECs). Our results showed that the OECs efficiently took up the NCs compared to the free curcumin, showing that NCs can ameliorate drug permeability.

Synthesis and Characterization of Nanostructured Lipid Nanocarriers for Enhanced Sun Protection Factor of Octyl p-methoxycinnamate

Sunlight is important to health, but higher exposure to radiation causes early aging of the skin and skin damage that can lead to skin cancers. This study aimed at producing a stable octyl p-methoxycinnamate (OMC)-loaded nanostructured lipid carrier (NLC) sunscreen, which can help in the photoprotective effect. NLC was produced by emulsification-sonication method and these systems were composed of myristyl myristate (MM), caprylic capric triglyceride (CCT), Tween® 80 (TW), and soybean phosphatidylcholine (SP) and characterized by dynamic light scattering (DLS), zeta potential (ZP) measurement, atomic force microscopy (AFM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and in vitro release studies. Pre-formulation studies were performed changing TW concentrations and no differences were found at concentrations of 1.0 and 2.0%. Two selected formulations were designed and showed an average size of 91.5-131.7, polydispersity index > 0.2, and a negative value of ZP. AFM presented a sphere-like morphology and SEM showed ability to form a thin film. DSC exhibited that the incorporation of OMC promoted reduction of enthalpy due to formation of a more amorphous structure. Drug release shows up to 55.74% and 30.57%, and this difference could be related to the presence of SP in this formulation that promoted a more amorphous structure; the release mechanism study indicated Fickian diffusion and relaxation. Sun protection factor (SPF) evaluation was performed using NLC and presented values around 40, considerably higher than those observed in the literature. The developed formulations provide a beneficial alternative to conventional sunscreen formulations.

Formulation and Characterization of Solid Lipid Nanoparticles Loading RF22-c, a Potent and Selective 5-LO Inhibitor, in a Monocrotaline-Induced Model of Pulmonary Hypertension

Pulmonary arterial hypertension (PAH) is a rare but fatal disease characterized by persistent elevated blood pressure in the pulmonary circulation, due to increased resistance to blood flow, through the lungs. Advances in the understanding of the pathobiology of PAH clarify the role of leukotrienes (LTs) that appear to be an exciting new target for disease intervention. Over the years, our group has long investigated this field, detecting the 1,2-benzoquinone RF-22c as the most powerful and selective competitive inhibitor of the enzyme 5-lipoxygenase (5-LO). With the aim to improve the bioavailability of RF-22c and to confirm the role of 5-LO as therapeutic strategy for PAH treatment, we developed a solid lipid nanoparticle (SLN) loaded with drug. Therefore, in monocrotaline (MCT) rat model of PAH, the role of 5-LO has been investigated through the formulation of RF-22c-SLN. The rats were randomly grouped into control group, MCT group, and MCT + RF22-c group. After 21 days, all the animals were sacrificed to perform functional and histological evaluations. RF22-c-SLN treatment was able to significantly reduce the mean pulmonary arterial pressure (mPAP) and precapillary resistance (R-pre) compared to the MCT group. The MCT induced rise in medial wall thickness of pulmonary arterioles, and the cardiomyocytes width were significantly attenuated by RF22-c-SLN formulation upon treatment. The results showed that the selective inhibition of 5-LO improved hemodynamic parameters as well as vascular and cardiac remodeling by preventing induced pulmonary hypertension. The improved sustained release properties and targeting abilities achieved with the innovative nanotechnological approach may be therapeutically beneficial for PAH patients as a consequence of the increase of pharmacological effects and of the possible reduction and/or optimization of the drug frequency of administration.

Lipid Nanoparticles and Active Natural Compounds: A Perfect Combination for Pharmaceutical Applications

Phytochemicals represent an important class of bioactive compounds characterized by significant health benefits. Notwithstanding these important features, their potential therapeutic properties suffer from poor water solubility and membrane permeability limiting their approach to nutraceutical and pharmaceutical applications. Lipid nanoparticles are well known carrier systems endowed with high biodegradation and an extraordinary biocompatible chemical nature, successfully used as platform for advanced delivery of many active compounds, including the oral, topical and systemic routes. This article is aimed at reviewing the last ten years of studies about the application of lipid nanoparticles in active natural compounds reporting examples and advantages of these colloidal carrier systems.

Development of Betamethasone Dipropionate-Loaded Nanostructured Lipid Carriers for Topical and Transdermal Delivery

Introduction

Betamethasone dipropionate is a highly effective corticosteroid anti-inflammatory. However, the main drawback of its topical use is the limited skin penetration into deeper skin layers. Also, its systemic use has shown many side effects.

Objective

The goal of this research was to formulate betamethasone dipropionate in nanostructured lipid carriers (NLC) formulae that contain oleic acid to aid its penetration to deeper skin layers and to aid absorption to local regions upon topical application.

Methods

NLC formulae were prepared by high shear homogenization then sonication. Formulae were characterized for their particle size, size distribution, electric potential, occlusion factor, entrapment efficiency, drug loading, transmission electron microscopy, in vitro drug release, and ex vivo skin penetration. Compatibility of ingredients with drug was tested using differential scanning calorimetry. Formulae were shown to have appropriate characteristics. NLC formulae were superior to traditional topical formulation in drug release.

Results

Upon testing ex vivo skin penetration, betamethasone dipropionate prepared in NLC formulae was shown to penetrate more efficiently into skin layers than when formulated as a traditional cream. NLC formulation that contained higher percentage of oleic acid showed higher penetration and higher amount of drug to pass through skin.

Conclusion

In general, NLC with lower oleic acid percentage was shown to deliver betamethasone dipropionate more efficiently into deeper skin layers while that of a higher oleic acid percentage was shown to deliver the drug more efficiently into deeper skin layers and through the skin, transdermally.

Preparation and characterization of nanostructured lipid carriers as drug delivery system: Influence of liquid lipid types on loading and cytotoxicity

In this study, we aimed to investigate the influence of liquid lipid types on different features of NLC. Four variations of liquid lipids such as coconut oil, fish oil, black seed oil and linseed oil were used, while for all variations, cetyl palmitate was used as the solid lipid. Different NLC were characterized and compared in terms of particle size, zeta potential, polydispersity index (PDI), drug entrapment percentage and drug loading capacity. The results indicated that NLC containing black seed oil has the smallest size. Other features like PDI, zeta potential and entrapment efficiency were the same for all the liquid lipids. By close margins, the NLC containing black seed oil had the highest percent of drug release and antioxidant activity compared to the rest. Diffusion was the major mechanism of the drug release according to the drug release kinetic fitted by Higuchi's model. Differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FT-IR) confirmed no strong interaction between NLC constituents. The particles showed spherical shape morphology under atomic force microscopy (AFM). According to the cell viability assay on MCF-7 cell line, the curcumin loaded NLC composed of linseed oil showed better cytotoxic activity compared to the free curcumin.

Biological activities of curcuminoids, other biomolecules from turmeric and their derivatives - A review

In recent years, several drugs have been developed deriving from traditional products and current drug research is actively investigating the possible therapeutic roles of many Ayruvedic and Traditional Indian medicinal therapies. Among those being investigated is Turmeric. Its most important active ingredient is curcuminoids. Curcuminoids are phenolic compounds commonly used as a spice, pigment and additive also utilized as a therapeutic agent used in several foods. Comprehensive research over the last century has revealed several important functions of curcuminoids. Various preclinical cell culture and animals studies suggest that curcuminoids have extensive biological activity as an antioxidant, neuroprotective, antitumor, anti-inflammatory, anti-acidogenic, radioprotective and arthritis. Different clinical trials also suggest a potential therapeutic role for curcuminoids in numerous chronic diseases such as colon cancer, lung cancer, breast cancer, inflammatory bowel diseases. The aim of this review is to summarize the chemistry, analog, metal complex, formulations of curcuminoids and their biological activities.

Biocompatible Lipid Nanoparticles as Carriers To Improve Curcumin Efficacy in Ovarian Cancer Treatment

Curcumin is a natural molecule with proved anticancer efficacy on several human cancer cell lines. However, its clinical application has been limited due to its poor bioavailability. Nanocarrier-based drug delivery approaches could make curcumin dispersible in aqueous media, thus overtaking the limits of its low solubility. The aim of this study was to increase the bioavailability and the antitumoral activity of curcumin, by entrapping it into nanostructured lipid carriers (NLCs). For this purpose here we describe the preparation and characterization of three kinds of curcumin-loaded NLCs. The nanosystems allowed the achievement of a controlled release of curcumin, the amounts of curcumin released after 24 h from Compritol-Captex, Compritol-Miglyol, and Compritol NLCs being, respectively, equal to 33, 28, and 18% w/w on the total entrapped curcumin. Considering the slower curcumin release profile, Compritol NLCs were chosen to perform successive in vitro studies on ovarian cancer cell lines. The results show that curcumin-loaded NLCs maintain anticancer activity, and reduce cell colony survival more effectively than free curcumin. As an example, the ability of A2780S cells to form colonies was decreased after treatment with 5 μM free curcumin by 50% ± 6, whereas, at the same concentration, the delivery of curcumin with NLC significantly (p < 0.05) inhibited colony formation to approximately 88% ± 1, therefore potentiating the activity of curcumin to inhibit A2780S cell growth. The obtained results clearly suggest that the entrapment of curcumin into NLCs increases curcumin efficacy in vitro, indicating the potential use of NLCs as curcumin delivery systems.

Doxorubicin and curcumin co-delivery by lipid nanoparticles for enhanced treatment of diethylnitrosamine-induced hepatocellular carcinoma in mice

At present, the treatment of hepatocellular carcinoma (HCC) is an international problem. The delivery of a chemotherapeutic agent and chemosensitizer using nanocarriers has been suggested as a novel and promising strategy in cancer treatment. However, such studies in HCC remain very limited. In this study, we developed doxorubicin (DOX) and curcumin (Cur) co-delivery lipid nanoparticles (DOX/Cur-NPs) and examined its inhibitory effect on diethylnitrosamine (DEN)-induced HCC in mice. DOX/Cur-NPs displayed the physicochemical characterizations with uniform particle size, high encapsulation efficacy and sustained release profile. In DNE-induced HCC mice treated with DOX/Cur-NPs, we observed decreased liver damage assessed by serum ALT and AST levels, liver/body weight ratio, and histopathological analysis. Compared with DOX-loaded nanoparticles (DOX-NPs), DOX/Cur-NPs induced increased Caspase-3 and Bax/Bcl-2 ratio, and decreased C-myc, PCNA and VEGF. The results revealed the synergistic effect of DOX/Cur-NPs on the apoptosis, proliferation and angiogenesis of HCC. The mRNA levels of MDR1, bcl-2 and HIF-1α, and protein levels of P-gp, Bcl-2 and HIF-1α were decreased in DOX/Cur-NPs than those in DOX-NPs, indicating that Cur might reverse multidrug resistance (MDR) through these pathways. In HCC cells, enhanced cytotoxicity and decreased IC50 and resistant index further confirmed the synergistic effects of DOX/Cur-NPs than DOX-NPs. Our studies suggest that simultaneous delivery of DOX and Cur by DOX/Cur-NPs may be a promising treatment for HCC.

"Curcumin, the King of Spices": Epigenetic Regulatory Mechanisms in the Prevention of Cancer, Neurological, and Inflammatory Diseases

Curcumin (diferuloylmethane), a polyphenolic compound, is a component of Curcuma longa, commonly known as turmeric. It is a well-known anti-inflammatory, anti-oxidative, and anti-lipidemic agent and has recently been shown to modulate several diseases via epigenetic regulation. Many recent studies have demonstrated the role of epigenetic inactivation of pivotal genes that regulate human pathologies, such as neurocognitive disorders, inflammation, obesity, and cancers. Epigenetic changes involve changes in DNA methylation, histone modifications, or altered microRNA expression patterns which are known to be interconnected and play a key role in tumor progression and failure of conventional chemotherapy. The majority of epigenetic changes are influenced by lifestyle and diets. In this regard, dietary phytochemicals as dietary supplements have emerged as a promising source that are able to reverse these epigenetic alterations, to actively regulate gene expression and molecular targets that are known to promote tumorigenesis, and also to prevent age-related diseases through epigenetic modifications. There have been several studies which reported the role of curcumin as an epigenetic regulator in neurological disorders, inflammation, and in diabetes apart from cancers. The epigenetic regulatory roles of curcumin include (1) inhibition of DNA methyltransferases (DNMTs), which has been well defined from the recent studies on its function as a DNA hypomethylating agent; (2) regulation of histone modifications via regulation of histone acetyltransferases (HATs) and histone deacetylases (HDACs); and (3) regulation of micro RNAs (miRNA). This review summarizes the current knowledge on the effect of curcumin in the treatment and/or prevention of inflammation, neurodegenerative diseases, and cancers by regulating histone deacetylases, histone acetyltransferases, and DNA methyltransferases.

Neurological recovery and antioxidant effects of curcumin for spinal cord injury in the rat: a network meta-analysis and systematic review

Spinal cord injury (SCI) is a devastating condition affecting young, healthy individuals worldwide. Existing agents have inadequate therapeutic efficacy, and some are associated with side effects. Our objective is to summarize and critically assess the neurological recovery and antioxidant effects of curcumin for treatment of SCI in rat models. PubMed, Embase, and Chinese databases were searched from their inception date to February 2014. Two reviewers independently selected animal studies that evaluated neurological recovery and antioxidant effects of curcumin, compared to placebo, in rats with SCI, extracted data, and assessed the methodological quality. A pair-wise analysis and a network meta-analysis were performed. Eight studies with adequate randomization were selected and included in the systematic review. Two studies had a higher methodological quality. Overall, curcumin appears to significantly improve neurological function, as assessed using the Basso, Beattie, Bresnahan (BBB) locomotor rating scale (four studies, n=132; pooled mean difference [MD]=3.09; 95% confidence interval [CI], 3.40-4.45; p=0.04), in a random-effects model and decrease malondialdehyde (MDA) using a fixed-effects model (four studies, n=56; pooled MD=-1.00; 95% CI=-1.59 to -0.42; p=0.00008). Effect size, assessed using the BBB scale, increased gradually with increasing curcumin dosage. The difference between low- and high-dose curcumin using the BBB scale was statistically significant. Neurological recovery and antioxidant effects of curcumin were observed in rats with SCI despite poor study methodological quality.

Codelivery of doxorubicin and curcumin with lipid nanoparticles results in improved efficacy of chemotherapy in liver cancer

Liver cancer is a leading cause of cancer deaths worldwide. The combination therapy of cytotoxic and chemosensitizing agents loaded in nanoparticles has been highlighted as an effective treatment for different cancers. However, such studies in liver cancer remain very limited. In our study, we aim to develop a novel lipid nanoparticles loaded with doxorubicin (DOX) (an effective drug for liver cancer) and curcumin (Cur) (a chemosensitizer) simultaneously, and we examined the efficacy of chemotherapy in liver cancer. DOX and Cur codelivery lipid nanoparticles (DOX/Cur-NPs) were successfully prepared using a high-pressure microfluidics technique, showing a mean particle size of around 90 nm, a polydispersity index <0.3, and a zeta potential <-10 mV. The encapsulation efficacy was >90% for both DOX and Cur. The blank lipid nanoparticles were nontoxic, as determined by a cell cytotoxicity study in human normal liver cells L02 and liver cancer cells HepG2. In vitro DOX release studies revealed a sustained-release pattern until 48 hours in DOX/Cur-NPs. We found enhanced cytotoxicity and decreased inhibitory concentration (IC)50 in HepG2 cells and reduced cytotoxicity in L02 cells treated with DOX/Cur-NPs, suggesting the synergistic effects of DOX/Cur-NPs compared with free DOX and DOX nanoparticles (NPs). The optimal weight ratio of DOX and Cur was 1:1. Annexin-V-fluorescein isothiocyanate/propidium iodide double staining showed enhanced apoptosis in HepG2 cells treated with DOX/Cur-NPs compared with free DOX and DOX-NPs. An in vivo experiment showed the synergistic effect of DOX/Cur-NPs compared with DOX-NPs on liver tumor growth inhibition. Taken together, the simultaneous delivery of DOX and Cur by DOX/Cur-NPs might be a promising treatment for liver cancer.

Current nanotechnology approaches for the treatment and management of diabetic retinopathy

Diabetic retinopathy (DR) is a consequence of diabetes mellitus at the ocular level, leading to vision loss, and contributing to the decrease of patient's life quality. The biochemical and anatomic abnormalities that occur in DR are discussed in this review to better understand and manage the development of new therapeutic strategies. The use of new drug delivery systems based on nanoparticles (e.g. liposomes, dendrimers, cationic nanoemulsions, lipid and polymeric nanoparticles) is discussed along with the current traditional treatments, pointing out the advantages of the proposed nanomedicines to target this ocular disease. Despite the multifactorial nature of DR, which is not entirely understood, some strategies based on nanoparticles are being exploited for a more efficient drug delivery to the posterior segment of the eye. On the other hand, the use of some nanoparticles also seems to contribute to the development of DR symptoms (e.g. retinal neovascularization), which are also discussed in light of an efficient management of this ocular chronic disease.

HDAC and HAT inhibitors differently affect analgesia mediated by group II metabotropic glutamate receptors

Background

Histone deacetylases (HDACs) and histone acetyltransferases (HATs) are key players in epigenetic regulation of gene expression. Analgesic activity by HDAC inhibitors has been reported in different pain models including inflammatory and neuropathic pain. These drugs interfere with gene expression through different mechanisms including chromatin remodeling and/or activation of transcription factors. Among other targets, HDAC inhibitors regulate metabotropic glutamate receptors type 2 (mGlu2) expression in central and peripheral central nervous system. However whether inhibition of HAT activity also regulates mGlu2 expression has not been reported.

Findings

Here we report that curcumin (CUR), a naturally occurring compound endowed with p300/CREB-binding protein HAT inhibitory activity, is able to induce a drastic down-regulation of the mGlu2 receptor in the mouse spinal cord after systemic administration together with a marked hypoacetylation of histones H3 and H4 in dorsal root ganglia (DRG). Furthermore, the analgesic activity of the mGlu2/3 agonist, LY379268 is lost after a 3-day treatment with CUR. Conversely the analgesic activity of LY379268 is potentiated in mice pretreated for 5 consecutive days with the HDAC inhibitor, Suberoylanilide Hydroxamic Acid (SAHA), known to induce mGlu2-upregulation.

Conclusions

Our results demonstrate that systemically injected CUR is able to inhibit H3 and H4 acetylation in the DRG and to down-regulate mGlu2 receptors in the spinal cord. We also demonstrate that long term modification of the mGlu2 expression affects the analgesic properties of the orthosteric mGlu2/3 agonist, LY379268. These data open up the possibility that epigenetic modulators might be given in combination with “traditional” drugs in a context of a multi target approach for a better analgesic efficacy.

Rivastigmine-loaded in situ gelling nanostructured lipid carriers for nose to brain delivery

In the current research work, rivastigmine (RV)-loaded in situ gelling nanostructured lipid carriers (NLCs) were developed for nose to brain delivery. NLCs were fabricated by ethanol injection method using glyceryl monosterate, Capmul MCM C8, Lecithin and Tween 80. NLCs showed average particle size of 123.2 ± 2.3 nm with entrapment efficiency of 68.34 ± 3.4%. DSC, XRD and IR studies showed complete amorphization and incorporation of the drug into nanoparticles. NLCs were incorporated into an in situ gelling system using 0.8% gellan gum and 15% Lutrol F 127. RV in situ gel showed excellent elasticity, rheology, mucoadhesion and adhesiveness to facilitate its adhesion to the upper nasal mucosa. NLC-based in situ gel showed a 2-fold increase in nasal permeation of the drug over plain RV solution. In situ gelling NLCs showed a 3-fold increase in enzyme inhibition efficacy.

Curcumin alleviates neuropathic pain by inhibiting p300/CBP histone acetyltransferase activity-regulated expression of BDNF and cox-2 in a rat model

The management of neuropathic pain is still a major challenge because of its unresponsiveness to most common treatments. Curcumin has been reported to play an active role in the treatment of various neurological disorders, such as neuropathic pain. Curcumin has long been recognized as a p300/CREB-binding protein (CBP) inhibitor of histone acetyltransferase (HAT) activity. However, this mechanism has never been investigated for the treatment of neuropathic pain with curcumin. The aim of the present study was to investigate the anti-nociceptive role of curcumin in the chronic constriction injury (CCI) rat model of neuropathic pain. Furthermore, with this model we investigated the effect of curcumin on P300/CBP HAT activity-regulated release of the pro-nociceptive molecules, brain-derived neurotrophic factor (BDNF) and cyclooxygenase-2 (Cox-2). Treatment with 40 and 60 mg/kg body weight curcumin for 7 consecutive days significantly attenuated CCI-induced thermal hyperalgesia and mechanical allodynia, whereas 20 mg/kg curcumin showed no significant analgesic effect. Chromatin immunoprecipitation analysis revealed that curcumin dose-dependently reduced the recruitment of p300/CBP and acetyl-Histone H3/acetyl-Histone H4 to the promoter of BDNF and Cox-2 genes. A similar dose-dependent decrease of BDNF and Cox-2 in the spinal cord was also observed after curcumin treatment. These results indicated that curcumin exerted a therapeutic role in neuropathic pain by down-regulating p300/CBP HAT activity-mediated gene expression of BDNF and Cox-2.