Encapsulation of curcumin into layered double hydroxides improve their anticancer and antiparasitic activity

Plant bioactive compounds alleviate photoinduced retinal damage and asthenopia: Mechanisms, synergies, and bioavailability

The retina, an important tissue of the eye, is essential in visual transmission and sustaining adequate eyesight. However, oxidative stress and inflammatory reactions can harm retinal structure and function. Recent studies have demonstrated that exposure to light can induce oxidative stress and inflammatory reactions in retinal cells, thereby facilitating the progression of retinal damage-related diseases and asthenopia. Plant bioactive compounds such as anthocyanin, curcumin, resveratrol, lutein, zeaxanthin, epigallocatechin gallate, and quercetin are effective in alleviating retinal damage and asthenopia. Their strong oxidation resistance and unique chemical structure can prevent the retina from producing reactive oxygen species and regulating eye muscle relaxation, thus alleviating retinal damage and asthenopia. Additionally, the combination of these active ingredients produces a stronger antioxidant effect. Consequently, understanding the mechanism of retinal damage caused by light and the regulation mechanism of bioactive compounds can better protect the retina and reduce asthenopia.

Investigation and multiscale modeling of PVA/SA coated poly lactic acid scaffold containing curcumin loaded layered double hydroxide nanohybrids

Applying hydrophilic coatings on polymeric nanofibers combined with layered double hydroxide (LDH) not only enhances the efficiency of drug delivery systems but also increases cell adhesion. This work aimed to prepare poly(vinyl alcohol)/sodium alginate (PVA/SA) (2/1)-coated poly(lactic acid) (PLA) nanofibers containing curcumin-loaded layered double hydroxide (LDH) and to investigate their drug release and mechanical properties and their biocompatibility. The optimum PLA nanofibrous sample was considered to be that based on 3 wt% of curcumin-loaded LDH (PLA-3%LDH) with a drug encapsulation efficiency of ∼18% in which a minimum average nanofiber diameter of ∼476 nm along with a high tensile strength of 3.00 MPa were obtained. In the next step, a PVA/SA (2/1) layer was coated on the PLA-3%LDH; as a result, the hydrophilicity of the sample was improved and the elongation at break was decreased remarkably. In this regard the cell viability reached 80% for the coated PLA. Moreover, the formation of a layer of (PVA/SA) on the PLA nanofibers lowered the burst release and resulted in a more sustained drug release, which is a vital feature in dermal applications. A multiscale modeling method was applied for simulation of the mechanical properties of the composite scaffold and the results showed that this method can predict the data with 83% accuracy. The results of this study indicate that the formation of a layer of PVA/SA (2/1) has a significant effect on hydrophilicity and consequently improves cell adhesion and proliferation.

Modular nanotheranostic agents for protistan parasitic diseases: Magic bullets with tracers

Protistan parasitic infections contribute significantly to morbidity and mortality, causing more than 2 billion human infections annually. However, current treatments are often limited; due to ineffective drugs and drug resistance, thus better options are urgently required. In the present context, theranostics agents are those that offer simultaneous detection, diagnosis and even treatment of protistan parasitic diseases. "Nanotheranostics" is the term used to describe such agents, that are around 100 nm or less in size. Anti-parasitic activity of nanoparticles (NPs) has been reported, and many have useful intrinsic imaging properties, but it is perhaps their multifunctional nature that offers the greatest potential. NPs may be used as adapters onto which various subunits with different functions may be attached. These subunits may facilitate targeting parasites, coupled with toxins to eradicate parasites, and probe subunits for detection of particles and/or parasites. The modular nature of nano-platforms promises a "mix and match" approach for the construction of tailored agents by using combinations of these subunits against different protistan parasites. Even though many of the subunits have shown promise alone, these have not yet been put together convincingly enough to form working theranostics against protistan parasites. Although the clinical application of nanotheranostics to protistan parasitic infections in humans requires more research, we conclude that they offer not just a realisation of Paul Ehrlich's long imagined "magic bullet" concept, but potentially are magic bullets combined with tracer bullets.

Retinal protective effect of curcumin metabolite hexahydrocurcumin against blue light-induced RPE damage

BACKGROUND

Age-related macular degeneration (AMD) is a disease of retinal pigment epithelium (RPE) cells. We have previously demonstrated that blue light can damage RPE cells and their underlying mechanisms. We found that hexahydrocurcumin (HHC), a metabolite of curcumin, had better retinal protection than curcumin. However, the involved mechanisms remain unclear.

METHODS

By exposing ARPE-19 human RPE cells and mouse primary RPE cells to blue light, the intracellular mechanisms of HHC in cells were investigated, including the proliferation of RPE cells and the effects of HHC on activating intracellular protective mechanisms and related factors. Next-generation sequencing (NGS) RNA sequencing revealed the underlying mechanisms involved in the induction and regulation of HHC treatment following blue light exposure.

RESULTS

HHC promoted autophagy by enhancing autophagic flux, reduced oxidative stress and endoplasmic reticulum (ER) stress, and effectively reversed blue light-induced cell death. RNA sequencing-based bioinformatics approaches comprehensively analyze HHC-mediated cellular processes.

CONCLUSION

Our findings elucidate the mechanisms of HHC against blue light damage in RPE cells and are beneficial for the development of natural metabolite-based preventive drugs or functional foods.

Nanohybrid of Thymol and 2D Simonkolleite Enhances Inhibition of Bacterial Growth, Biofilm Formation, and Free Radicals

Due to the current concerns against opportunistic pathogens and the challenge of antimicrobial resistance worldwide, alternatives to control pathogen growth are required. In this sense, this work offers a new nanohybrid composed of zinc-layered hydroxide salt (Simonkolleite) and thymol for preventing bacterial growth. Materials were characterized with XRD diffraction, FTIR and UV–Vis spectra, SEM microscopy, and dynamic light scattering. It was confirmed that the Simonkolleite structure was obtained, and thymol was adsorbed on the hydroxide in a web-like manner, with a concentration of 0.863 mg thymol/mg of ZnLHS. Absorption kinetics was described with non-linear models, and a pseudo-second-order equation was the best fit. The antibacterial test was conducted against Escherichia coli O157:H7 and Staphylococcus aureus strains, producing inhibition halos of 21 and 24 mm, respectively, with a 10 mg/mL solution of thymol–ZnLHS. Moreover, biofilm formation of Pseudomonas aeruginosa inhibition was tested, with over 90% inhibition. Nanohybrids exhibited antioxidant activity with ABTS and DPPH evaluations, confirming the presence of the biomolecule in the inorganic matrix. These results can be used to develop a thymol protection vehicle for applications in food, pharmaceutics, odontology, or biomedical industries.

Utility of Intravenous Curcumin Nanodelivery Systems for Improving In Vivo Pharmacokinetics and Anticancer Pharmacodynamics

Curcumin nanoformulations for intravenous injection have been developed to offset poor absorption, biotransformation, degradation, and excessive clearance associated with parenteral delivery. This review investigates (1) whether intravenous nanoformulations improve curcumin pharmacokinetics (PK) and (2) whether improved PK yields greater therapeutic efficacy. Standard PK parameters (measured maximum concentration [Cmax], area under the curve [AUC], distribution volume [Vd], and clearance [CL]) of intravenously administered free curcumin in mice and rats were sourced from literature and compared to curcumin formulated in nanoparticles, micelles, and liposomes. The studies that also featured analysis of pharmacodynamics (PD) in murine cancer models were used to determine whether improved PK of nanoencapsulated curcumin resulted in improved PD. The distribution and clearance of free and nanoformulated curcumin were very fast, typically accounting for >80% curcumin elimination from plasma within 60 min. Case-matched analysis demonstrated that curcumin nanoencapsulation generally improved curcumin PK in terms of measured Cmax (n = 27) and AUC (n = 33), and to a lesser extent Vd and CL. However, when the data were unpaired and clustered for comparative analysis, only 5 out of the 12 analyzed nanoformulations maintained a higher relative curcumin concentration in plasma over time compared to free curcumin. Quantitative analysis of the mean plasma concentration of free curcumin versus nanoformulated curcumin did not reveal an overall marked improvement in curcumin PK. No correlation was found between PK and PD, suggesting that augmentation of the systemic presence of curcumin does not necessarily lead to greater therapeutic efficacy.

Layered Double Hydroxides-Loaded Sorafenib Inhibit Hepatic Stellate Cells Proliferation and Activation In Vitro and Reduce Fibrosis In Vivo

A core feature of liver fibrosis is the activation of hepatic stellate cells (HSCs), which are transformed into myofibroblasts and lead to the accumulation of extracellular matrix (ECM) proteins. In this study, we combined in vitro cellular efficacy with in vivo antifibrosis performance to evaluate the outcome of sorafenib (SRF) loaded layered double hydroxide (LDH) nanocomposite (LDH-SRF) on HSCs. The cellular uptake test has revealed that sorafenib encapsulated LDH nanoparticles were efficiently internalized by the HSC-T6 cells, synergistically inducing apoptosis of hepatic stellate cells. Moreover, the apoptosis rate and the migration inhibition rate induced by LDHs-SRF were 2.5 and 1.7 times that of SRF. Western Blot showed that the TGF-β1/Smad/EMT and AKT signaling pathway was significantly inhibited in HSC-T6 cells treated with LDHs-SRF. For the in vivo experiment, LDHs-SRF were administered to rat models of CCl₄-induced liver fibrosis. H&E, masson and sirius red staining showed that LDHs-SRF could significantly reduce inflammatory infiltrate and collagen fiber deposition and immunohistochemical results found that LDHs-SRF treatment significantly inhibited the protein expressions of α-SMA in the liver, these results suggesting that LDHs-SRF exhibited better anti-fibrotic effect than SRF alone and significantly inhibited the proliferation and activation of rat hepatic stellate cells and collagen fiber synthesis.

A comprehensive review of the therapeutic potential of curcumin nanoformulations

Today, due to the prevalence of various diseases such as the novel coronavirus (SARS-CoV-2), diabetes, central nervous system diseases, cancer, cardiovascular disorders, and so on, extensive studies have been conducted on therapeutic properties of natural and synthetic agents. A literature review on herbal medicine and commercial products in the global market showed that curcumin (Cur) has many therapeutic benefits compared to other natural ingredients. Despite the unique properties of Cur, its use in clinical trials is very limited. The poor biopharmaceutical properties of Cur such as short half-life in plasma, low bioavailability, poor absorption, rapid metabolism, very low solubility (at acidic and physiological pH), and the chemical instability in body fluids are major concerns associated with the clinical applications of Cur. Recently, nanoformulations are emerging as approaches to develop and improve the therapeutic efficacy of various drugs. Many studies have shown that Cur nanoformulations have tremendous therapeutic potential against various diseases such as SARS-CoV-2, cancer, inflammatory, osteoporosis, and so on. These nanoformulations can inhibit many diseases through several cellular and molecular mechanisms. However, successful long-term clinical results are required to confirm their safety and clinical efficacy. The present review aims to update and explain the therapeutic potential of Cur nanoformulations.

A Novel Green Approach to Synthesize Curcuminoid-Layered Double Hydroxide Nanohybrids: Adroit Biomaterials for Future Antimicrobial Applications

Thermal instability, photodegradation, and poor bioavailability of natural active ingredients are major drawbacks in developing effective natural product-based antimicrobial formulations. These inherited issues could be fruitfully mitigated by the introduction of natural active ingredients into various nanostructures. This study focuses on the development of a novel green mechanochemical synthetic route to incorporate curcuminoids into Mg-Al-layered double hydroxides. The developed one-pot and scalable synthetic approach makes lengthy synthesis procedures using toxic solvents redundant, leading to improved energy efficiency. The hydrotalcite-shaped nanohybrids consist of surface and interlayer curcuminoids that have formed weak bonds with layered double hydroxides as corroborated by X-ray diffractograms, X-ray photoelectron spectra, and Fourier transmission infrared spectra. The structural and morphological properties resulted in increased thermal stability of curcuminoids. Slow and sustained release of the curcuminoids was observed at pH 5.5 for a prolonged time up to 7 h. The developed nanohybrids exhibited zeroth-order kinetics, favoring transdermal application. Furthermore, the efficacy of curcuminoid incorporated LDHs (CC-LDH) as an anticolonization agent was investigated against four wound biofilm-forming pathogens, Pseudomonas aeruginosa, Staphylococcus aureus, methicillin-resistant Staphyloccocus aureus, and Candida albicans, using a broth dilution method and an in vitro biofilm model system. Microbiological studies revealed a 54-58% reduction in biofilm formation ability of bacterial pathogens in developed nanohybrids compared to pure curcuminoids. Therefore, the suitability of these green-chemically synthesized CC-LDH nanohybrids for next-generation antimicrobial applications with advanced dermatological/medical properties is well established.

Antiviral activity against Zika virus of a new formulation of curcumin in poly lactic-co-glycolic acid nanoparticles

OBJECTIVES

In the search of an effective antiviral formulation, the natural product curcumin (CUR) was encapsulated into poly(lactic-co-glycolic acid) nanoparticles, a non-toxic bioresorbable and biocompatible copolymer. The resulting CUR containing particles (PLGA-CUR NPs) were characterized and analysed for antiviral activity against Zika virus (ZIKV) infection.

METHODS

The PLGA-CUR NPs were characterized by Fourier transform infrared, differential scanning calorimetry, dynamic light scattering, scanning electron microscopy and thermogravimetric analysis and release profile. Cytotoxicity of PLGA-CUR and the antiviral activity against ZIKV were determined in Vero cells. The effect of PLGA-CUR NPs on viral RNA synthesis and protein expression was analysed by RT-qPCR and immunofluorescence staining, respectively.

KEY FINDINGS

The PLGA-CUR NPs showed an appropriate in vitro drug release profile. Our studies of the antiviral activity of PLGA-CUR NPs and CUR against ZIKV by virus yield reduction as well as viral RNA synthesis and protein expression have shown that PLGA-CUR formulation is more effective than free CUR to inhibit ZIKV infection of Vero cells.

CONCLUSIONS

Our results demonstrate for the first time the antiviral activity against ZIKV of PLGA nanoparticles charged with CUR, suggesting that PLGA-CUR NPs are promising candidates for a drug formulation against human pathogenic flaviviruses.