Preparation and Evaluation of Chrysin Encapsulated in PLGA- PEG Nanoparticles in the T47-D Breast Cancer Cell Line

Chrysin loaded bilosomes improve the hepatoprotective effects of chrysin against CCl4 induced hepatotoxicity in mice

In the present work, chrysin loaded bilosomes were formulated, characterized and evaluated to enhance the hepatoprotective activity of drug. Accordingly, chrysin loaded bilosomes were prepared by applying the thin film hydration method; also, fractional factorial design was used to optimize the production conditions of nanoformulations. The prepared formulations were subjected to different methods of characterization; then the hepatoprotective activity of the optimized one was evaluated in the CCl4 hepatointoxicated mice model. Optimized chrysin loaded bilosomes showed a spherical shape with a particle size of 232.97 ± 23 nm, the polydispersity index of 0.35 ± 0.01, the zeta potential of -44.5 ± 1.27 mv, the entrapment efficiency of 96.77 ± 0.18%, the drug loading % of 6.46 ± 0.01 and the release efficiency of 42.25 ± 1.04 during 48 h. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging assay demonstrated the superiority of the anti-oxidant potential of chrysin loaded bilosomes, as compared to pure chrysin. This was in agreement with histopathological investigations, showing significant improvement in serum hepatic biomarkers of CCl4 intoxicated mice treated with chrysin loaded bilosomes, as compared with free chrysin. These results, thus, showed the potential use of bilosomes to enhance the hepatoprotective activity of chrysin via oral administration.

Chrysin and chrysin-loaded nanocarriers induced immunogenic cell death on B16 melanoma cells

Induction of immunogenic cell death (ICD) is a promising strategy for cancer immunotherapy. Chrysin, which has potential anticancer effects, faces limitations in clinical applications due to its poor water solubility. This study aimed to formulate chrysin with PEG-poly(α-benzylcarboxylate-ε-caprolactone) (PBCL) nanoparticles (NPs) and assess their anticancer and ICD-inducing potency in melanoma cells, comparing with free chrysin. The co-solvent evaporation method was employed to develop chrysin-loaded NPs. UV spectroscopy, dynamic light scattering, and the dialysis bag method were used to evaluate the encapsulation efficiency (EE), particle size, polydispersity index (PDI), and drug release profile, respectively. The anticancer effects of the drugs were assessed using the MTT and trypan blue exclusion assays. Flow cytometry was employed to evaluate apoptosis and calreticulin (CRT) expression. ELISA and western blotting were used to detect heat shock protein 90 (HSP90), Annexin A1, GRP78 (Glucose-related protein78), and activated protein kinase R-like endoplasmic reticulum kinase (p-PERK). Chrysin-loaded PEG-PBCL NPs (chrysin-PEG-PBCL) showed an EE of 97 ± 1%. Chrysin-PEG-PBCL was 38.18 ± 3.96 nm in size, with a PDI being 0.62 ± 0.23. Chrysin-PEG-PBCL showed an initial burst release, followed by sustained release over 24 h. Chrysin-PEG-PBCL exhibited a significantly stronger anticancer effect in B16 cells. Chrysin-PEG-PBCL was found to be more potent in inducing apoptosis. Both free chrysin and chrysin NPs induced ICD as indicated by an increase in the levels of ICD biomarkers. Interestingly, chrysin NPs were found to be more potent inducers of ICD than the free drug. These findings demonstrate that chrysin and chrysin-PEG-PBCL NPs can induce ICD in B16 cells. PEG-PBCL NPs significantly enhanced the potency of chrysin in inducing ICD compared to its free form.

Herbal nanomedicines: Recent advancements, challenges, opportunities and regulatory overview

BACKGROUND

Herbal Nano Medicines (HNMs) are nano-sized medicine containing herbal drugs as extracts, enriched fractions or biomarker constituents. HNMs have certain advantages because of their increased bioavailability and reduced toxicities. There are very few literature reports that address the common challenges of herbal nanoformulations, such as selecting the type/class of nanoformulation for an extract or a phytochemical, selection and optimisation of preparation method and physicochemical parameters. Although researchers have shown more interest in this field in the last decade, there is still an urgent need for systematic analysis of HNMs.

PURPOSE

This review aims to provide the recent advancement in various herbal nanomedicines like polymeric herbal nanoparticles, solid lipid nanoparticles, phytosomes, nano-micelles, self-nano emulsifying drug delivery system, nanofibers, liposomes, dendrimers, ethosomes, nanoemulsion, nanosuspension, and carbon nanotube; their evaluation parameters, challenges, and opportunities. Additionally, regulatory aspects and future perspectives of herbal nanomedicines are also being covered to some extent.

METHODS

The scientific data provided in this review article are retrieved by a thorough analysis of numerous research and review articles, textbooks, and patents searched using the electronic search tools like Sci-Finder, ScienceDirect, PubMed, Elsevier, Google Scholar, ACS, Medline Plus and Web of Science.

RESULTS

In this review, the authors suggested the suitability of nanoformulation for a particular type of extracts or enriched fraction of phytoconstituents based on their solubility and permeability profile (similar to the BCS class of drugs). This review focuses on different strategies for optimising preparation methods for various HNMs to ensure reproducibility in context with all the physicochemical parameters like particle size, surface area, zeta potential, polydispersity index, entrapment efficiency, drug loading, and drug release, along with the consistent therapeutic index.

CONCLUSION

A combination of herbal medicine with nanotechnology can be an essential tool for the advancement of herbal medicine research with enhanced bioavailability and fewer toxicities. Despite the challenges related to traditional medicine's safe and effective use, there is huge scope for nanotechnology-based herbal medicines. Overall, it is well stabilized that herbal nanomedicines are safer, have higher bioavailability, and have enhanced therapeutic value than conventional herbal and synthetic drugs.

Anticancer Effect of Alginate-Chitosan Hydrogel Loaded with Curcumin and Chrysin on Lung and Breast Cancer Cell Lines

OBJECTIVE

We conducted the present study to investigate the anticancer effects of curcumin and chrysin loaded in the alginate-chitosan hydrogel on breast cancer (T47D) and lung cancer (A549).

BACKGROUND

Cancer, which is defined as abnormal cell growth, is one of the biggest public health problems in the world. Natural compounds, such as polyphenols, are used as chemo-preventive and chemotherapeutic agents in different types of cancer owing to their antioxidant, antineoplastic, and cytotoxic properties. To improve their bioavailability and releasing behavior, hydrogel systems with high drug loading and stability and hydrophilic nature have been designed.

METHODS

The curcumin-chrysin-loaded alginate-chitosan hydrogels were prepared through the ionic gelation mechanism utilizing CaCl2. The prepared hydrogels were studied by using the Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The MTT and DAPI staining assays were employed for cytotoxicity and apoptosis studies of curcumin-chrysin-loaded alginate-chitosan hydrogels. The effects of the curcumin-chrysin-loaded alginate-chitosan hydrogels on the cell cycle of cell lines T47D and A549 were also evaluated using the propidium iodide staining.

RESULTS

The FTIR indicated specific bands at 1607 and 1422 cm-1 (the carbonyl of alginate) at 834 cm-1 (sodium alginate), 1447 cm-1, and 1026 cm-1 (COOH and C-O stretching bands alginate and chitosan). The curcumin-chrysin-loaded alginate-chitosan hydrogels could significantly (p<0.05) reduce the viability and induce apoptosis, Morover, cause G2/M arrest of the cell cycle in both A549 and T47D cell lines.

CONCLUSION

The alginate-chitosan hydrogels could work best as an enhanced anticancer drug delivery system.

An updated review on the versatile role of chrysin in neurological diseases: Chemistry, pharmacology, and drug delivery approaches

Neurological diseases are responsible for a large number of morbidities and mortalities in the world. Flavonoids are phytochemicals that possess various health-promoting impacts. Chrysin, a natural flavonoid isolated from diverse fruits, vegetables, and even mushrooms, has several pharmacological activities comprising antioxidant, anti-inflammatory, antiapoptotic, anticancer, and neuroprotective effects. The current study was designed to review the relationship between chrysin administration and neurological complications by discussing the feasible mechanism and signaling pathways. Herein, we mentioned the sources, pharmacological properties, chemistry, and drug delivery systems associated with chrysin pharmacotherapy. The role of chrysin was discussed in depression, anxiety, neuroinflammation, Alzheimer's disease, Parkinson's disease, Huntington's disease, epilepsy, cerebral ischemia, spinal cord injury, neuropathy, Multiple Sclerosis, and Guillain-Barré Syndrome. The findings indicate that chrysin has protective effects against neurological conditions by modulating oxidative stress, inflammation, and apoptosis in animal models. However, more studies should be done to clear the neuroprotective effects of chrysin.

Gold Nanoparticles- Boon in Cancer Theranostics

BACKGROUND

Cancer is the world's second-largest cause of death, with an estimated 9.6 million fatalities in 2018. Malignant tumour (cancer) is caused by a mixture of genetic modifications due to the environmental variables that tend to activate or inactivate different genes, ultimately resulting in neoplastic transformations. Cancer is a multi-stage process that results from the conversion of the ordinary cells to tumour cells and progresses from a pre-cancer lesion to abnormal growth.

METHODS

Chemotherapy inhibits the ability of the cells to divide rapidly in an abnormal manner, but this treatment simultaneously affects the entire cellular network in the human body leading to cytotoxic effects. In this review article, the same issue has been addressed by discussing various aspects of the newer class of drugs in cancer therapeutics, i.e., Gold Nanoparticles (AuNPs) from metal nanoparticle (NP) class.

RESULTS

Metal NPs are advantageous over conventional chemotherapy as the adverse drug reactions are lesser. Additionally, ease of drug delivery, targeting and gene silencing are salient features of this treatment. Functionalized ligand-targeting metal NPs provide better energy deposition control in tumour. AuNPs are promising agents in the field of cancer treatment and are comprehensively studied as contrast agents, carriers of medicinal products, radiosensitizers and photothermal agents. For the targeted delivery of chemotherapeutic agents, AuNPs are used and also tend to enhance tumour imaging in vivo for a variety of cancer types and diseased organs.

CONCLUSION

The first part of the review focuses on various nano-carriers that are used for cancer therapy and deals with the progression of metal NPs in cancer therapy. The second part emphasizes the use of nanotechnology by considering the latest studies for diagnostic and therapeutic properties of AuNPs. AuNPs present the latest studies in the field of nanotechnology, which leads to the development of early-stage clinical trials. The next part of the review discusses the major features of five principal types of AuNPs: gold nanorods, gold nanoshells, gold nanospheres, gold nanocages, and gold nanostars that have their application in photothermal therapy (PTT).

Emerging cellular and molecular mechanisms underlying anticancer indications of chrysin

Chrysin has been shown to exert several beneficial pharmacological activities. Chrysin has anti-cancer, anti-viral, anti-diabetic, neuroprotective, cardioprotective, hepatoprotective, and renoprotective as well as gastrointestinal, respiratory, reproductive, ocular, and skin protective effects through modulating signaling pathway involved in apoptosis, oxidative stress, and inflammation. In the current review, we discussed the emerging cellular and molecular mechanisms underlying therapeutic indications of chrysin in various cancers. Online databases comprising Scopus, PubMed, Embase, ProQuest, Science Direct, Web of Science, and the search engine Google Scholar were searched for available and eligible research articles. The search was conducted by using MeSH terms and keywords in title, abstract, and keywords. In conclusion, experimental studies indicated that chrysin could ameliorate cancers of the breast, gastrointestinal tract, liver and hepatocytes, bladder, male and female reproductive systems, choroid, respiratory tract, thyroid, skin, eye, brain, blood cells, leukemia, osteoblast, and lymph. However, more studies are needed to enhance the bioavailability of chrysin and evaluate this agent in clinical trial studies.

Evaluation of the Hemocompatibility and Anticancer Potential of Poly(ε-Caprolactone) and Poly(3-Hydroxybutyrate) Microcarriers with Encapsulated Chrysin

In this work, novel chrysin-loaded poly(ε-caprolactone) and poly(3-hydroxybutyrate) microcarriers were synthesized according to a modified oil-in-water single emulsion/solvent evaporation method, utilizing poly(vinyl alcohol) surfactant as stabilizer and dispersing agent for the emulsification, and were evaluated for their physico-chemical and morphological properties, loading capacity and entrapment efficiency and in vitro release of their load. The findings suggest that the novel micro-formulations possess a spherical and relatively wrinkled structure with sizes ranging between 2.4 and 24.7 µm and a highly negative surface charge with z-potential values between (-18.1)-(-14.1) mV. The entrapment efficiency of chrysin in the poly(ε-caprolactone) and poly(3-hydroxybutyrate) microcarriers was estimated to be 58.10% and 43.63%, whereas the loading capacity was found to be 3.79% and 15.85%, respectively. The average release percentage of chrysin was estimated to be 23.10% and 18.01%, respectively. The novel micromaterials were further biologically evaluated for their hemolytic activity through hemocompatibility studies over a range of hematological parameters and cytoxicity against the epithelial human breast cancer cell line MDA-MB 231. The poly(ε-caprolactone) and poly(3-hydroxybutyrate) microcarriers reached an IC50 value with an encapsulated chrysin content of 149.19 µM and 312.18 µM, respectively, and showed sufficient blood compatibility displaying significantly low (up to 2%) hemolytic percentages at concentrations between 5 and 500 µg·mL-1.

Broad-Spectrum Preclinical Antitumor Activity of Chrysin: Current Trends and Future Perspectives

Pharmacological profile of phytochemicals has attracted much attention to their use in disease therapy. Since cancer is a major problem for public health with high mortality and morbidity worldwide, experiments have focused on revealing the anti-tumor activity of natural products. Flavonoids comprise a large family of natural products with different categories. Chrysin is a hydroxylated flavonoid belonging to the flavone category. Chrysin has demonstrated great potential in treating different disorders, due to possessing biological and therapeutic activities, such as antioxidant, anti-inflammatory, hepatoprotective, neuroprotective, etc. Over recent years, the anti-tumor activity of chrysin has been investigated, and in the present review, we provide a mechanistic discussion of the inhibitory effect of chrysin on proliferation and invasion of different cancer cells. Molecular pathways, such as Notch1, microRNAs, signal transducer and activator of transcription 3 (STAT3), nuclear factor-kappaB (NF-κB), PI3K/Akt, MAPK, etc., as targets of chrysin are discussed. The efficiency of chrysin in promoting anti-tumor activity of chemotherapeutic agents and suppressing drug resistance is described. Moreover, poor bioavailability, as one of the drawbacks of chrysin, is improved using various nanocarriers, such as micelles, polymeric nanoparticles, etc. This updated review will provide a direction for further studies in evaluating the anti-tumor activity of chrysin.

Hesperidin Loaded on Gold Nanoparticles as a Drug Delivery System for a Successful Biocompatible, Anti-Cancer, Anti-Inflammatory and Phagocytosis Inducer Model

Hesperidin is a flavonoid glycoside with proven therapeutic activities for various diseases, including cancer. However, its poor solubility and bioavailability render it only slightly absorbed, requiring a delivery system to reach its therapeutic target. Hesperidin loaded on gold nanoparticles (Hsp-AuNPs) was prepared by a chemical synthesis method. Various characterization techniques such as UV-VIS spectroscopy, FTIR, XRD, FESEM, TEM and EDX, Zeta potential analysis, particle size analysis, were used to confirm the synthesis of Hsp-AuNPs. The cytotoxic effect of Hsp-AuNPs on human breast cancer cell line (MDA-MB-231) was assessed using MTT and crystal violet assays. The results revealed significant decrease in proliferation and inhibition of growth of the treated cells when compared with human normal breast epithelial cell line (HBL-100). Determination of apoptosis by fluorescence microscope was also performed using acridine orange-propidium iodide dual staining assay. The in vivo study was designed to evaluate the toxicity of Hsp-AuNPs in mice. The levels of hepatic and kidney functionality markers were assessed. No significant statistical differences were found for the tested indicators. Histological images of liver, spleen, lung and kidney showed no apparent damages and histopathological abnormalities after treatment with Hsp-AuNPs. Hsp-AuNPs ameliorated the functional activity of macrophages against Ehrlich ascites tumor cells-bearing mice. The production of the pro-inflammatory cytokines was also assessed in bone marrow–derived macrophage cells treated with Hsp-AuNPs. The results obviously demonstrated that Hsp-AuNPs treatment significantly inhibited the secretion of IL-1β, IL-6 and TNF.

Inclusion complexes between chrysin and amino-appended β-cyclodextrins (ACDs): Binding behavior, water solubility, in vitro antioxidant activity and cytotoxicity

Solid inclusion complexes between chrysin and four amino-appended β-cyclodextrins (ACDs) were prepared by suspension method and characterized in solid and solution states by kinds of analytical methods. The scanning electron microscopy (SEM) showed distinct micro-morphologies of them. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis revealed their unique thermal properties, such as decomposition temperatures and endothermic points. Powder X-ray diffractometry (XRD) analysis disclosed their unique crystal patterns. Their nuclear magnetic resonance (NMR) analyses provided the variations of chemical shifts before and after the formation of inclusion complexes. Their binding stability constants (Ks) were 574, 842, 704, and 474 L·mol^-1, respectively, as determined by spectral titration. A 1:1 inclusion mode with self-assembly of their amino side chains inside the ACD cavity was proposed based on Job plot and 2D-ROESY experiments. Water solubility of chrysin was promoted up to 4411.98 μg·mL^-1 after formation of inclusion complexes with ACDs, better than that of β-CD and its derivatives, i.e., HP- and SBE-β-CD. In vitro antioxidant activity of chrysin was also improved after inclusion complexation by the DPPH scavenging assay. Furthermore, in vitro cytotoxicity of solid inclusion complexes towards three human cancer cell lines, A549, HT-29 and HCT116 were enhanced significantly.

The Relationship between Pharmacological Properties and Structure- Activity of Chrysin Derivatives

Chrysin is a natural product of a flavonoid compound. Chemically, chrysin consists of two phenyl rings (A and B) and a heterocyclic ring (C). Biologically, chrysin exerts many different physiological activities. In recent years, with the in-depth development for more active drugs, the synthesis and biological activities of chrysin derivatives have been well studied. Besides, structure-activity relationship of chrysin revealed that the chemical construction meets the critical chemical structural necessities of flavonoids for numerous pharmacological activities. It is generally believed that modified chrysin could be more potent than unmodified chrysin. Different modification in the rings of chrysin could possess various degrees of biological activities. This review aims to summarize the mechanism for the activities of chrysin and its derivatives in different rings. We also explored the relationship between biological function and structure-activity of substituted chrysin derivatives with different functional groups. The influence of chrysin derivatives on the proliferation and apoptosis of cancer cells is also investigated. Development of novel drugs based on the biological functions of chrysin could better improve clinical outcomes of affected population, especially for tumor patients and diabetic patients.

Curcumin in combination with anti-cancer drugs: A nanomedicine review

A huge surge of research is being conducted on combination therapy with anticancer compounds formulated in the form of nanoparticles (NPs). Numerous advantages like dose minimalization and synergism, reversal of multi drug resistance (MDRs), enhanced efficacy have emerged with nanoencapsulation of chemotherapeutic agents with chemo-sensitizing agent like curcumin. Within last couple of years various nano-sized formulations have been designed and tested both in vitro with cell lines for different types of cancers and in vivo with cancer types and drug resistance models. Despite the combinatorial models being advanced, translation to human trials has not been as smooth as one would have hoped, with as few as twenty ongoing clinical trials with curcumin combination, with less than 1/10th being nano-particulate formulations. Mass production of nano-formulation based on their physico-chemical and pharmacokinetics deficits poses as major hurdle up the ladder. Combination of these nano-sized dosage with poorly bioavailable drugs, unspecific target binding ability and naturally unstable curcumin further complicates the formulation aspects. Emphasis is now therefore being laid on altering natural forms of curcumin and usage of formulations like prodrug or coating of curcumin to overcome stability issues and focus more on enhancing the pharmaceutical and therapeutic ability of the nano-composites. Current studies and futuristic outlook in this direction are discussed in the review, which can serve as the basis for upcoming research which could boost commercial translational of improved nano-sized curcumin combination chemotherapy.

Anti-Tumorigenic Activity of Chrysin from Oroxylum indicum via Non-Genotoxic p53 Activation through the ATM-Chk2 Pathway

The p53 tumor suppressor plays critical roles in cell cycle regulation and apoptotic cell death in response to various cellular stresses, thereby preventing cancer development. Therefore, the activation of p53 through small molecules is an attractive therapeutic strategy for the treatment of cancers retaining wild-type p53. We used a library of 700 Myanmar wild plant extracts to identify small molecules that induce p53 transcriptional activity. A cell-based screening method with a p53-responsive luciferase-reporter assay system revealed that an ethanol extract of Oroxylum indicum bark increased p53 transcriptional activity. Chrysin was isolated and identified as the active ingredient in the O. indicum bark extract. A treatment with chrysin increased p53 protein expression and the p53-mediated expression of downstream target genes, and decreased cell viability in MCF7 cells, but not in p53-knockdown MCF7 cells. We also found that chrysin activated the ATM-Chk2 pathway in the absence of DNA damage. Hence, the inactivation of the ATM-Chk2 pathway suppressed p53 activation induced by chrysin. These results suggest the potential of chrysin as an anti-cancer drug through the activation of p53 without DNA damage.

Nanoscale modification of chrysin for improved of therapeutic efficiency and cytotoxicity

Chrysin, as a flavone, is a promising drug candidate because of its multifaceted properties, such as anti-inflammatory, antioxidant and anticancer. However, its poor bioavailability is a bottleneck for pharmaceutical applications. To enhance the bioactive effects, chrysin-loaded poly (D,L-lactic-co-glycolic acid) and polyvinyl alcohol were successfully prepared to overcome problems associated with chrysin. The properties of modified nanochrysin were analysed by in vitro dissolution study, XRD, FTIR and SEM. Free radical scavenging potentials of the modified nanochrysin against DPPH were confirmed based on its stable antioxidant effects. A DNA instability enhancement was observed after H₂O₂ exposure, whereas chrysin decreased the H₂O₂ activity, and modified nanochrysin was more potent in this regard. Blood compatibility on red blood cells was confirmed by haemolytic and in vitro cytotoxicity assays. The in vitro anticancer activity of the modified nanochrysin towards MCF-7 and SKOV-3 cell lines using various parameters was investigated. The nanochrysin was found to exert cell growth arrest against both cancer cells in a dose-dependent manner. IC₅₀ value was significantly decreased in nanochrysin in comparison with pure chrysin and induced apoptotic cell death pathway. The results of this study suggest that the nanochrysin might be used for medical applications and offer a beneficial formulation for chemotherapy.

Chrysin: Sources, beneficial pharmacological activities, and molecular mechanism of action

In recent years, public and scientific interest in plant flavonoids has tremendously increased because of their postulated health benefits. This review was mainly focuses on the flavone chrysin (5,7-dihydroxyflavone), which occurs naturally in many plants, honey, and propolis. A number of in vitro and in vivo studies have revealed the therapeutic effects of chrysin against various diseases. In general, chrysin exhibits many biological activities and pharmacological effects, including antioxidant, anti-inflammatory, anticancer, and antiviral activities. Moreover, many studies have reported on the bioavailability of chrysin. Because of its compromised bioavailability and enhanced protein stability, chrysin solid lipid nanoparticle (SLN) synthesis avoids proteolytic degradation and sustained release of drug delivery. To clarify the mechanism of action of chrysin, researchers have investigated the structural binding relationship of chrysin through the docking computation method.

Co-Delivery of Curcumin and Chrysin by Polymeric Nanoparticles Inhibit Synergistically Growth and hTERT Gene Expression in Human Colorectal Cancer Cells

Nanoparticle (NP)-based combinational chemotherapy has been proposed as a potent approach for improving intracellular drug concentrations and attaining synergistic effects in colorectal cancer therapy. Here, two well-known herbal substances, Curcumin (Cur) and Chrysin (Chr), were co-encapsulated in PEGylated PLGA NPs and investigated their synergistic inhibitory effect against Caco-2 cancer cells. Characterization of nanoformulated drugs was determined using DLS, FTIR, TEM, and SEM. Drug release study was performed using dialysis method. MTT and real-time PCR assays were applied to evaluate the cytotoxic effects of free and nano-encapsulated drugs on expression level of hTERT in Caco-2 cells. The results showed that free drugs and nano-formulations exhibited a dose-dependent cytotoxicity against Caco-2 cells and especially, Cur-Chr-PLGA/PEG NPs had more synergistic antiproliferative effect and significantly arrested the growth of cancer cells than the other groups (P < 0.05). Real-time PCR results revealed that Cur, Chr, and combination of Cur-Chr in free and encapsulated forms inhibited hTERT gene expression. Also, it was found that Cur-Chr-PLGA/PEG NPs than free combination forms could further decline hTERT expression in all concentration (P < 0.05). In summary, our study represents the first report of nano-combinational application of the natural herbal substances with a one-step fabricated codelivery system for effective colorectal cancer combinational chemotherapy.

Synergistic Anticancer Effects of Silibinin and Chrysin in T47D Breast Cancer Cells

Objective:

Breast cancer is one of the most significant causes of female cancer death worldwide. Although several chemotherapeutics have been developed to treat this type of cancer, issues remain such as low survival rates and high reoccurrence after chemotherapy and radiotherapy. To explore a chemopreventive approach to enhancing breast cancer treatment efficacy, the antiproliferative effects of a combination of chrysin and silibinin, two herbal substances, in T47D breast cancer cells were assessed.

Materials and Methods:

Cytotoxicity of the agents singly and in combination was evaluated by MTT assay. Also, qRT-PCR was used to measure the expression levels of hTERT and cyclin D1 genes after 48 h treatment.

Results:

Cell viability assays revealed that chrysin or silibinin alone inhibited proliferation in a dose and time-dependent manner, and combining the drugs synergistically induced growth inhibition in the breast cancer cell line. The precise nature of this interaction was further analyzed by the median-effect method, where the combination indices (CI) were <1 for combination treatments, indicating synergism regarding T47D cell proliferation. qPCR results showed that the drug combination also synergistically down-regulated the mRNA levels of hTERT and cyclin D1 at all used concentrations compared with the drugs used alone after 48 h treatment (P ≤ 0.05).

Conclusion:

The data provide evidence that synergistic antiproliferative effects of Chrysin and Silibinin are linked to the down-regulation of cyclin D1 and hTERT genes, and suggest that their combination may have therapeutic value in treatment of breast cancer.

Improved chemotherapeutic efficacy of injectable chrysin encapsulated by copolymer nanoparticles

Chrysin is a flavone that is found in several plants and in honeycomb and possesses various biological activities. However, its low solubility means it has poor bioavailability, which must be resolved to enable its pharmaceutical applications. In the present study, chrysin was incorporated into methoxy poly(ethylene glycol)-β-polycaprolactone nanoparticles (chrysin-NPs) using the oil-in-water technique in order to overcome problems associated with chrysin. The properties of chrysin-NPs were analyzed, and their anticancer effects were investigated in vitro and in vivo. Chrysin-NPs were 77 nm sized (as determined by dynamic laser light scattering) and showed a monodisperse distribution. The zeta potential of chrysin-NPs was -2.22 mV, and they were spherically shaped by cryo-transmission electron microscopy (cryo-TEM). The loading efficiency of chrysin-NPs was 46.96%. Chrysin-NPs retained the cytotoxicity of chrysin in A549 cells. The therapeutic efficacies of chrysin-NPs were compared with those of chrysin in an A549-derived xenograft mouse model. Chrysin-NPs were intravenously injected at a 10 times lower dosage than chrysin 3 times per week (q2d×3/week). However, free chrysin was orally administrated 5 times per week (q1d×5/week). Chrysin-NP-treated group showed significant tumor growth delay, which was similar to that of chrysin-treated group, despite the considerably lower total dosage. These results suggest that the injectable chrysin-NPs enhance therapeutic efficacy in vivo and offer a beneficial formulation for chemotherapy.

PLGA-PEG Nanoparticles Coated with Anti-CD45RO and Loaded with HDAC Plus Protease Inhibitors Activate Latent HIV and Inhibit Viral Spread

Activating HIV-1 proviruses in latent reservoirs combined with inhibiting viral spread might be an effective anti-HIV therapeutic strategy. Active specific delivery of therapeutic drugs into cells harboring latent HIV, without the use of viral vectors, is a critical challenge to this objective. In this study, nanoparticles of poly(lactic-co-glycolic acid)-polyethylene glycol diblock copolymers conjugated with anti-CD45RO antibody and loaded with the histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA) and/or protease inhibitor nelfinavir (Nel) were tested for activity against latent virus in vitro. Nanoparticles loaded with SAHA, Nel, and SAHA + Nel were characterized in terms of size, surface morphology, zeta potential, entrapment efficiency, drug release, and toxicity to ACH-2 cells. We show that SAHA- and SAHA + Nel-loaded nanoparticles can target latently infected CD4(+) T-cells and stimulate virus production. Moreover, nanoparticles loaded with SAHA + NEL were capable of both activating latent virus and inhibiting viral spread. Taken together, these data demonstrate the potential of this novel reagent for targeting and eliminating latent HIV reservoirs.