Nanoencapsulation of the flavonoid dihydromyricetin protects against the genotoxicity and cytotoxicity induced by cationic nanocapsules

The mechanism, biopolymers and active compounds for the production of nanoparticles by anti-solvent precipitation: A review

The anti-solvent precipitation method has been investigated to produce biopolymeric nanoparticles in recent years. Biopolymeric nanoparticles have better water solubility and stability when compared with unmodified biopolymers. This review article focuses on the analysis of the state of the art available in the last ten years about the production mechanism and biopolymer type, as well as the used of these nanomaterials to encapsulate biological compounds, and the potential applications of biopolymeric nanoparticles in food sector. The revised literature revealed the importance to understand the anti-solvent precipitation mechanism since biopolymer and solvent types, as well as anti-solvent and surfactants used, can alter the biopolymeric nanoparticles properties. In general, these nanoparticles have been produced using polysaccharides and proteins as biopolymers, especially starch, chitosan and zein. Finally, it was identified that those biopolymers produced by anti-solvent precipitation were used to stabilize essential oils, plant extracts, pigments, and nutraceutical compounds, promoting their application in functional foods.

Dihydromyricetin attenuates intracerebral hemorrhage by reversing the effect of LCN2 via the system Xc- pathway

BACKGROUND

The limited understanding of the pathological mechanisms of intracerebral hemorrhage (ICH) and the absence of successful therapies lead to poor prognoses for patients with ICH. Dihydromyricetin (DMY) has many physiological functions, such as regulating lipid and glucose metabolism and modulating tumorigenesis. Moreover, DMY has been proven to be an effective treatment of neuroprotection. However, no reports to date have been made regarding the impact of DMY on ICH.

PURPOSE

This investigation aimed to identify the role of DMY on ICH in mice and the underlying mechanisms.

METHODS/RESULTS

This study demonstrated that DMY treatment effectively reduced hematoma size and cell apoptosis of brain tissue, and improved neurobehavioral outcomes in mice with ICH. Transcriptional and network pharmacological analyses revealed that lipocalin-2 (LCN2) was a potential target of DMY in ICH. After ICH, LCN2 mRNA and protein expression in brain tissue increased and DMY could inhibit the expression of LCN2. The rescue experiment with the implementation of LCN2 overexpression verified these observations. Furthermore, after DMY treatment, there was a significant decrease in cyclooxygenase 2 (COX2), phospho-extracellular regulated protein kinase (P-ERK), iron deposition, and the number of abnormal mitochondria, which were reversed by the overexpression of LCN2. Proteomics analysis suggests that SLC3A2 may be the downstream target of LCN2, promoting ferroptosis. Finally, LCN2 was shown to bind to SLC3A2 and regulate the downstream glutathione (GSH) synthesis and Glutathione Peroxidase 4 (GPX4) expression and glutathione (GSH) synthesis, as determined by molecular docking and co-immunoprecipitation analysis.

CONCLUSION

Our study confirmed for the first time that DMY might offer a favorable treatment for ICH through its action on LCN2. The possible mechanism for this could be that DMY reverses the inhibitory effect of LCN2 on the system Xc-, lessening ferroptosis in brain tissue. The findings of this study offer a greater understanding of how DMY affects ICH at a molecular level and could be conducive to developing therapeutic targets for ICH.

Zwitterionic nanocapsules with pH- and thermal- responsiveness for drug-controlled release

The construction of an environmentally responsive drug-release system is of great significance for the treatment of special diseases. In particular, the construction of nanomaterials with pH- and thermal-responsiveness, which can effectively encapsulate drugs and control drug release, is becoming hot research. In this study, zwitterionic nanocapsules with stable core-shell structures were synthesized by inverse reversible addition-fragmentation transfer miniemulsion interfacial polymerization. To further study the structure and performance of the nanocapsules, the prepared nanocapsules were characterized by transmission electron microscopy, dynamic light dispersion, and zeta potential analysis. It was found that the nanocapsules had dual pH- and thermal- responsiveness, and the average particle size ranged from 178 to 142 nm when the temperature changed from 25 °C to 40 °C. In addition, bovine serum albumin (BSA) was encapsulated into nanocapsules, and sustained release experiments were conducted at 10 °C and 40 °C. The results showed that nanocapsules as carriers of BSA could achieve the purpose of sustained release of drugs, and showed different sustained release curves at different temperatures. Finally,in vitrocytotoxicity tests were performed to demonstrate the feasibility of their biomedical application. It is believed that the dual pH- and thermal- responsive nanocapsules are promising for drug-controlled release.

Copaiba Oil-Loaded Polymeric Nanocapsules: Production and In Vitro Biosafety Evaluation on Lung Cells as a Pre-Formulation Step to Produce Phytotherapeutic Medicine

Copaiba oil has been largely used due to its therapeutic properties. Nanocapsules were revealed to be a great nanosystem to carry natural oils due to their ability to improve the bioaccessibility and the bioavailability of lipophilic compounds. The aim of this study was to produce and characterize copaiba oil nanocapsules (CopNc) and to evaluate their hemocompatibility, cytotoxicity, and genotoxicity. Copaiba oil was chemically characterized by GC-MS and FTIR. CopNc was produced using the nanoprecipitation method. The physicochemical stability, toxicity, and biocompatibility of the systems, in vitro, were then evaluated. Β-bisabolene, cis-α-bergamotene, caryophyllene, and caryophyllene oxide were identified as the major copaiba oil components. CopNc showed a particle size of 215 ± 10 nm, a polydispersity index of 0.15 ± 0.01, and a zeta potential of -18 ± 1. These parameters remained unchanged over 30 days at 25 ± 2 °C. The encapsulation efficiency of CopNc was 54 ± 2%. CopNc neither induced hemolysis in erythrocytes, nor cytotoxic and genotoxic in lung cells at the range of concentrations from 50 to 200 μg·mL^-1. In conclusion, CopNc showed suitable stability and physicochemical properties. Moreover, this formulation presented a remarkable safety profile on lung cells. These results may pave the way to further use CopNc for the development of phytotherapeutic medicine intended for pulmonary delivery of copaiba oil.

Impact of free curcumin and curcumin nanocapsules on viability and oxidative status of neural cell lines

Curcumin is an active polyphenol substance found in the highest concentrations in the roots of Curcuma longa. Its health benefits have led to recent increases in the consumption of curcumin. It has anti-inflammatory and antioxidant activities and is a potent neuroprotective against diseases of the brain. Nevertheless, its low bioavailability and its relative difficulty crossing the blood-brain barrier limit curcumin's use for these purposes. Curcumin-loaded nanoparticles may be an effective treatment for several diseases although there is a paucity of studies reporting its safety in the central nervous system (CNS). Therefore, this study aimed to identify non-neurotoxic concentrations of free curcumin and two nanoformulations of curcumin. Cell lines BV-2 and SH-SY5Y, both originating from the CNS, were evaluated after 24, 48, and 72 h of treatment with free curcumin and nanocapsules We measured viability, proliferation, and dsDNA levels. We measured levels of reactive oxygen species and nitric oxide as proxies for oxidative stress in culture supernatants. We found that free curcumin was toxic at 10 and 20 µM, principally at 72 h. Nanoformulations were more neurotoxic than the free form. Safe concentrations of free curcumin are between 1-5 µM, and these concentrations were lower for nanoformulations. We determined the ideal concentrations of free curcumin and nanocapsules serving as a basis for studies of injuries that affect the CNS.

Molecular mechanisms and promising role of dihydromyricetin in cardiovascular diseases

Vine tea, a Chinese herbal medicine, is widely used in traditional Asian medicine to treat common health problems. Dihydromyricetin (DMY) is the main functional flavonoid compound extracted from vine tea. In recent years, preclinical studies have focused on the potential beneficial effects of dihydromyricetin, including glucose metabolism regulation, lipid metabolism regulation, neuroprotection, and anti-tumor effects. In addition, DMY may play a role in cardiovascular disease by resisting oxidative stress and participating in the regulation of inflammation. This review is the first review that summaries the applications of dihydromyricetin in cardiovascular diseases, including atherosclerosis, myocardial infarction, myocardial hypertrophy, and diabetic cardiomyopathy. We also clarified the underlying mechanisms and signaling pathways involved in the above process. The aim of this review is to provide a better understanding and quick overview for future researches of dihydromyricetin in the field of cardiovascular diseases, and more detailed and robust researches are needed for evaluation and reference.

Strategic developments in the drug delivery of natural product dihydromyricetin: applications, prospects, and challenges

Dihydromyricetin (DHM) is an important natural flavonoid that has attracted much attention because of its various functions such as protecting the cardiovascular system and liver, treating cancer and neurodegenerative diseases, and anti-inflammation effect, etc. Despite its great development potential in pharmacy, DHM has some problems in pharmaceutical applications such as low solubility, permeability, and stability. To settle these issues, extensive research has been carried out on its physicochemical properties and dosage forms to produce all kinds of DHM preparations in the past ten years. In addition, the combined use of DHM with other drugs is a promising strategy to expand the application of DHM. However, although invention patents for DHM preparations have been issued in several countries, the current transformation of DHM research results into market products is insufficient. To date, there is still a lack of deep research into the pharmacokinetics, pharmacodynamics, toxicology, and action mechanism of DHM preparations. Besides, preparations for combined therapy of DHM with other drugs are scarcely reported, which necessitates the development of dosage forms for this application. Apart from medicine, the development of DHM in the food industry is also of great potential. Due to its multiple effects and excellent safety, DHM preparations can be developed for functional drinks and foods. Through this review, we hope to draw more attention to the development potential of DHM and the above challenges and provide valuable references for the research and development of other natural products with a similar structure-activity relationship to this drug.

Eucalyptus oil nanoemulsions against eggs and larvae of Haemonchus contortus

Haemonchus contortus is a highly pathogenic and prevalent helminth that causes many deaths in sheep herds. Anthelmintics are usually employed to overcome this issue; however, they do not guarantee immediate and lasting efficacy because of the occurrence of drug-resistant parasites. Among substances that are used in scientific studies for parasitic control, essential oils are known to have different pharmacological properties. However, they demonstrate instability owing to several factors, and therefore, nanoemulsification is considered an alternative to control the instability and degradability of these compounds. The objective of this study was to evaluate the cytotoxicity of nanoemulsions containing essential oil of Eucalyptus globulus against the blood of healthy sheep and to verify their activity against the parasite H. contortus in sheep. The results presented adequate nanotechnological characteristics (diameter 72 nm, PDI 0.2, zeta -11 mV, and acidic pH) and adequate morphology. Further, the corona effect and cytotoxic profiles of the free oil and nanoemulsion against blood cells from healthy sheep were evaluated. The tests results did not present a toxicity profile. For evaluating efficacy, we observed an important anthelmintic action of the nanoemulsion containing oil in comparison to the free oil; the results demonstrate a potential role of the nanoemulsion in the inhibition of egg hatchability and the development of larvae L1 to L3 (infective stage). Based on these results, we developed an important and potential anthelmintic alternative for the control of the parasite H. contortus.

Nanostructured systems increase the in vitro cytotoxic effect of bullfrog oil in human melanoma cells (A2058)

The aim of this work was to investigate the in vitro cytotoxic effect of previously developed nanocapsules, nanoemulsion, and microemulsion based on bullfrog oil (BFO) against human melanoma cells (A2058). The nanosystems were produced as described in previous studies and characterized according to droplet/particle distribution and zeta potential. The biocompatibility was evaluated by the determination of the hemolytic potential against human erythrocytes. The cytotoxicity assessment was based on MTT and cell death assays, determination of Reactive Oxygen Species (ROS) levels, and cell uptake. The nanosystems were successfully reproduced and showed hemolytic potential smaller than 10% at all oil concentrations (50 and 100 µg.mL^-1) (p < 0.05). The MTT assay revealed that the nanosystems decreased the mitochondrial activity up to 92 ± 2% (p < 0.05). The study showed that the free BFO induced cell apoptosis, while all the nanostructured systems caused cell death by necrosis associated with a ROS overproduction. This can be related to the increased ability of the nanostructured systems to deliver the BFO across all cellular compartments (membrane, cytoplasm, and nucleus). Finally, these results elucidate the in vitro BFO nanosystems cytotoxic effect against human melanoma cells (A2058), revealing the emulsified ones as the most cytotoxic systems. Overall, the findings suggest that the safety and antineoplastic activity of these systems can be further investigated by in vivo studies.

Surface-functionalized curcumin-loaded polymeric nanocapsules could block apomorphine-induced behavioral changes in rats

BACKGROUND

Surface functionalization enhances the properties and characteristics of polymeric nanocapsules (NCs) mainly due to the surface charge, surfactants, and polymer coating type. Curcumin (CUR) is a bioactive compound with several proven pharmacological properties and low bioavailability. This study aimed to develop anionic (poly-ɛ-caprolactone; PCL) and cationic (Eudragit^® RS100 (EUD)) NCs prepared with sorbitan monostearate (Span 60^®) or sorbitan monooleate (Span 80^®), coated with d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and optimized using 2³ factorial analysis. Subsequently, the biological activity was evaluated.

METHODS

A two-level, three-factor design (polymer, Span type, and TPGS concentration) was used. The biological effects of CUR-loaded TPGS-coated cationic and anionic NCs were assessed in apomorphine-induced stereotyped behavior in rats.

RESULTS

The type of polymer (anionic or cationic) and Span^® had a factorial influence on the physical and chemical characteristics of NCs according to the changes in TPGS concentrations. Both cationic and anionic CUR-NCs could block apomorphine-induced behavioral changes.

CONCLUSIONS

The CUR-loaded TPGS-coated NCs proved to be a promising brain delivery system.

Characterization, Cytotoxicity and Anti-Inflammatory Effect Evaluation of Nanocapsules Containing Nicotine

(1) Background: Nanotechnology is an emerging field that can be applied in the biomedical area. In this study, Eudragit nanocapsules (NCs) containing nicotine were produced. Nicotine is the main alkaloid found in tobacco and has anti-inflammatory properties. NCs containing nicotine may be used as an adjuvant therapy in the treatment of inflammation in the central nervous system. (2) Methods: Nanocapsules were prepared by the interfacial deposition of the pre-formed polymer method and characterized in terms of zeta potential, diameter, polydispersity index, pH, encapsulation efficiency (EE), stability and sustained release profile. In vitro tests with the PC12 cell line were performed, such as MTT, LIVE/DEAD and ELISA assays, to verify their cytotoxic and anti-inflammatory effects. (3) Results: The nanocapsules presented satisfactory values of the characterization parameters; however, poor encapsulation was obtained for nicotine (8.17% ± 0.47). The in vitro tests showed that the treatment with nanocapsules reduced cell viability, which suggests that the Eudragit or the amount of polymer on top of the cells may be detrimental to them, as the cells were able to survive when treated with bulk nicotine. ELISA showed an increment in the expression of IL-6 and IL-1β, corroborating the hypothesis that NCs were toxic to the cells because of the increase in the levels of these pro-inflammatory cytokines. (4) Conclusions: This study demonstrates that NCs of Eudragit present toxicity. It is therefore necessary to improve NC formulation to obtain better values for the encapsulation efficiency and reduce toxicity of these nanodevices.

Biofilm inhibition by biocompatible poly(ε-caprolactone) nanocapsules loaded with essential oils and their cyto/genotoxicity to human keratinocyte cell line

Essential oils (EOs) of Thymus capitatus (Th) carvacrol chemotype and Origanum vulgare (Or) thymol and carvacrol chemotype were encapsulated in biocompatible poly(ε-caprolactone) nanocapsules (NCs). These nanosystems exhibited antibacterial, antifungal, and antibiofilm activities against Staphylococcus aureus, Escherichia coli, and Candida albicans. Th-NCs and Or-NCs were more effective against all tested strains than pure EOs and at the same time were not cytotoxic on HaCaT (T0020001) human keratinocyte cell line. The genotoxic effects of EO-NCs and EOs on HaCaT were evaluated using an alkaline comet assay for the first time, revealing that Th-NCs and Or-NCs did not induce DNA damage compared with untreated control HaCaT cells in vitro after 24 h. The cells morphological changes were assessed by label-free live cell Raman imaging. This study demonstrate the ability of poly(ε-caprolactone) nanocapsules loaded with thyme and oregano EOs to reduce microbial and biofilm growth and could be an ecological alternative in the development of new antimicrobial strategies.

UVB photoprotective capacity of hydrogels containing dihydromyricetin nanocapsules to UV-induced DNA damage

We evaluate the effect of cationic nanocapsules containing dihydromyricetin (DMY) flavonoid for safe topical use in photoprotection against UV-induced DNA damage. The stability was investigated for feasibility to produce hydrogels containing cationic nanocapsules of the flavonoid DMY (NC-DMY) for 90 days under three different storage conditions (4 ± 2 °C, 25 ± 2 °C, and 40 ± 2 °C), as well as evaluation of skin permeation and its cytotoxicity in skin cell lines. The physicochemical and rheological characteristics were maintained during the analysis period under the different aforementioned conditions. However, at 25 °C and 40 °C, the formulations indicated yellowish coloration and DMY content reduction. Therefore, the ideal storage condition of 4 °C was adopted. DMY remained in the stratum corneum and the uppermost layers of the skin. Regarding safety, all formulations demonstrated to be safe for topical application. NC-DMY exhibited a 50% Solar Protection Factor (SPF-DNA) against DNA damage caused by UVB radiation and demonstrated 99.9% protection against DNA lesion induction. These findings establish a promising formulation containing nanoencapsulated DMY flavonoids with a photoprotective and antioxidant potential of eliminating reactive oxygen species formed by solar radiation.

Antioxidant Activity of Encapsulated Extracts and Bioactives from Natural Sources

The low water solubility and low bioavailability of natural bioactive substances such as polyphenols and flavonoids, either in pure form or extracts, are a major concern in the pharmaceutical field and even on the food development sector. Although encapsulation has demonstrated success in addressing these drawbacks, it is important to evaluate the antioxidant activity of the encapsulated compounds. This article reviews the encapsulation of bioactive compounds from natural sources focusing their antioxidant activity after encapsulation. Attention is given to the methods and wall materials used, and the antioxidant activity methodologies (classical in vitro techniques such as DPPH, ORAC, FRAP and others, as well as in vivo/ex vivo tests to evaluate endogenous antioxidant enzymes or oxidative stress) applied to assess the antioxidant capacity are also comprehensively summarized.

In Vivo Antidepressant Effect of Passiflora edulis f. flavicarpa into Cationic Nanoparticles: Improving Bioactivity and Safety

A variety of neuroactive flavonoids can be found in the species of the Passiflora genus; however, their difficulty in crossing the blood-brain barrier limits their in vivo neuropharmacological activity. In this study, cationic nanoparticles were developed as a novel nanocarrier for improving the antidepressant activity of Passiflora edulis f. flavicarpa leaf extract. Formulations obtained using Eudragit E PO polymethylmethacrylate copolymer, as polymeric matrix had their physicochemical properties investigated. The analytical content of the flavonoids vicenin-2, orientin, isoorientin, vitexin, and isovitexin was determined in the plant extract. Small-sized and spherical nanoparticles loaded with Passiflora edulis f. flavicarpa were obtained with positive zeta potential and high encapsulation efficiency. In addition, the nanosystems were shown to be stable for at least 6 months. The antidepressant activity of P. edulis extract (50 and 100 mg/kg) as well as the extract-loaded nanoparticles (5 mg/kg) were investigated in mice using the forced swimming test, where the latter increased the potency of the former by 10-fold. In addition, histopathological and biochemical analysis confirmed the biocompatibility of the extract-loaded nanoparticles. This study demonstrated that the Eudragit cationic nanoparticles were able to improve the antidepressant activity of P. edulis in the central nervous system of mice.

Preclinical Research of Dihydromyricetin for Brain Aging and Neurodegenerative Diseases

Brain aging and neurodegenerative diseases share the hallmarks of slow and progressive loss of neuronal cells. Flavonoids, a subgroup of polyphenols, are broadly present in food and beverage and numerous studies have suggested that it could be useful for preventing or treating neurodegenerative diseases in humans. Dihydromyricetin (DHM) is one of the main flavonoids of some Asian medicinal plants that are used to treat diverse illness. The effects of DHM have been studied in different in vitro systems of oxidative damage and neuroinflammation, as well as in animal models of several neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease. Here we analyzed the most important effects of DHM, including its antioxidant, anti-inflammatory, and neuroprotective effects, as well as its ability to restore GABA neurotransmission and improve motor and cognitive behavior. We propose new areas of research that might contribute to a better understanding of the mechanism of action of this flavonoid, which could help develop a new therapy for aging and age-related brain diseases.