Stability and encapsulation efficiency of sulforaphane microencapsulated by spray drying

Potential mechanisms of cancer prevention and treatment by sulforaphane, a natural small molecule compound of plant-derived

Despite recent advances in tumor diagnosis and treatment technologies, the number of cancer cases and deaths worldwide continues to increase yearly, creating an urgent need to find new methods to prevent or treat cancer. Sulforaphane (SFN), as a member of the isothiocyanates (ITCs) family, which is the hydrolysis product of glucosinolates (GLs), has been shown to have significant preventive and therapeutic cancer effects in different human cancers. Early studies have shown that SFN scavenges oxygen radicals by increasing cellular defenses against oxidative damage, mainly through the induction of phase II detoxification enzymes by nuclear factor erythroid 2-related factor 2 (Nrf2). More and more studies have shown that the anticancer mechanism of SFN also includes induction of apoptotic pathway in tumor cells, inhibition of cell cycle progression, and suppression of tumor stem cells. Therefore, the application of SFN is expected to be a necessary new approach to treating cancer. In this paper, we review the multiple molecular mechanisms of SFN in cancer prevention and treatment in recent years, which can provide a new vision for cancer treatment.

Bioactive sulforaphane from cruciferous vegetables: advances in biosynthesis, metabolism, bioavailability, delivery, health benefits, and applications

Chronic inflammation-induced diseases (CID) are the dominant cause of death worldwide, contributing to over half of all global deaths. Sulforaphane (SFN) derived from cruciferous vegetables has been extensively studied for its multiple functional benefits in alleviating CID. This work comprehensively reviewed the biosynthesis, metabolism, bioavailability, delivery, health benefits, and applications of SFN and its potential mechanisms against CID (e.g., cancer, obesity, type 2 diabetes, et al.), and neurological disorders based on a decade of research. SFN exerts its biological functions through the hydrolysis of glucosinolates by gut microbiota, and exhibits rapid metabolism and excretion characteristics via metabolization of mercapturic acid pathway. Microencapsulation is an important way to improve the stability and targeted delivery of SFN. The health benefits of SNF against CID are attributed to the multiple regulatory mechanisms including modulating oxidative stress, inflammation, apoptosis, immune response, and intestinal homeostasis. The clinical applications of SFN and related formulations show promising potential; however, further exploration is required regarding the sources, dosages, toxicity profiles, and stability of SFN. Together, SFN is a natural product with great potential for development and application, which is crucial for the development of functional food and pharmaceutical industries.

Optimization of a Microencapsulation Process Using Oil-in-Water (O/W) Emulsion to Increase Thermal Stability of Sulforaphane

Sulforaphane (SFN) is a bioactive compound widely studied for its potential applications in pharmaceutical, nutraceutical, and food industries since it offers health benefits due to its nature as a Phase 2 enzyme inducer. Its application in the food industry has been limited because SFN is unstable at high temperatures in an aqueous milieu. An option to increase SFN stability and protect it from thermal degradation is microencapsulation. The aim of this work was to optimize a microencapsulation process using oil-in-water emulsion to increase the thermal stability of SFN. The operation conditions that gave the highest entrapment efficiency were determined via experimental design and response surface methodology. Thermal degradation of microencapsulated SFN was studied at 37, 50, 60, and 70 °C. The optimum microencapsulation conditions were 8 min stirring, SFN/Gum Arabic ratio of 0.82, and surfactant/oil ratio of 1.0, resulting in an entrapment efficiency of 65%, which is the highest reported so far. The thermal stability of microencapsulated SFN was greatly enhanced compared with free SFN, with a 6-fold decrease in the degradation kinetic constant and a 41% increase in the activation energy. These results will contribute to a more efficient incorporation of SFN in various food matrices and explore new microencapsulation technologies to maximize the efficiency and stability of SFN.

Effective myocardial infarction treatment by targeted accumulation of Sulforaphane using porous magnetic silica nanoparticles

Myocardial infarction (MI) is a common cardiovascular pathology that induces extensive sterile inflammation during its early stages, posing a severe threat to human health. Effectively modulating cardiac inflammation may improve post-MI outcomes. Unfortunately, owing to the side effects of therapeutic drugs and cardiac coronary artery occlusion, current MI drugs are sub-optimal for the clinical management of ischemic myocardia. Sulforaphane (SFN) has been adopted for MI treatment due to its myocardial protective effects and low toxicity. However, the targeted accumulation of SFN in infarcted areas remains challenging. Herein, porous magnetic silica nanoparticles (PMSNs) were synthesized and loaded with SFN to improve the specificity of targeted SFN delivery to infarcted areas in mouse models of MI. PMSNs loaded with SFN (PMSNs + SFN) decreased the levels of pro-inflammatory cytokines, thus leading to the improvement of cardiac function and cell survival without adverse effects. To further explore SFN's mechanisms of action in MI, a cellular (in vitro) model was established via oxygen and glucose deprivation (OGD). HSF1 and Nrf2 knockdown resulted in a decrease of SFN-induced HSP70 expression in OGD cells. Moreover, as a result of HSP70 knockdown, the pro-survival and anti-inflammatory effects of SFN were blocked in OGD cells. The level of pro-inflammatory cytokines decreased upon HSP70 overexpression, and cell survival rate increased under OGD conditions. In summary, the results confirm that PMSNs are capable of transporting SFN to infarcted areas in the myocardium, where the drug exerts cardioprotective effects against myocardial injury by up-regulating HSP70 through Nrf2/HSF1.

Microcapsules of Sacha Inchi seed oil (Plukenetia volubilis L.) obtained by spray drying as a potential ingredient to formulate functional foods

Sacha Inchi seed oil (SIO) is rich in omega 3, 6, and 9 fatty acids with important health benefits, but is temperature sensitive. Spray drying is a technology that improves the long-term stability of bioactive compounds. This work aimed to study the effect of three different homogenization techniques on some physical properties and bioavailability of microcapsules of Sacha Inchi seed oil (SIO) emulsions obtained by spray drying. Emulsions were formulated with SIO (5%, w/w), maltodextrin:sodium caseinate as wall material (10%, w/w; 85:15), Tween 20 (1%, w/w) and Span 80 (0.5%, w/w) as surfactants and water up to 100% (w/w). Emulsions were prepared using high-speed (Dispermat D-51580, 18,000 rpm, 10 min), conventional (Mixer K-MLIM50N01, Turbo speed, 5 min), and ultrasound probe (Sonics Materials VCX 750, 35% amplitude, 750 W, 30 min) homogenization. SIO microcapsules were obtained in a Mini Spray B-290 (Büchi) using two inlet temperatures of the drying air (150 and 170 °C). Moisture, density, dissolution rate, hygroscopicity, drying efficiency (EY), encapsulation efficiency (EE), loading capacity, and oil release in digestive fluids in vitro were studied. Results showed that the microcapsules obtained by spray-drying had low moisture values and high encapsulation yield and efficiency values (greater than 50% and 70%, respectively). The thermogravimetric analysis indicates that heat protection was assured, enhancing the shelf life and the ability to withstand thermal food processing. Results suggest that spray-drying encapsulation could be a suitable technology to successfully microencapsulate SIO and enhance the absorption of bioactive compounds in the intestine. This work highlights the use of Latin American biodiversity and spray drying technology to ensure the encapsulation of bioactive compounds. This technology represents an opportunity for the development of new functional foods, improving the safety and quality of conventional foods.

Immunomodulatory and Antioxidant Effects of Spray-Dried Encapsulated Kale Sprouts after In Vitro Gastrointestinal Digestion

The health-related compounds present in kale are vulnerable to the digestive process or storage conditions. Encapsulation has become an alternative for their protection and takes advantage of their biological activity. In this study, 7-day-old Red Russian kale sprouts grown in the presence of selenium (Se) and sulfur (S) were spray-dried with maltodextrin to assess their capacity to protect kale sprout phytochemicals from degradation during the digestion process. Analyses were conducted on the encapsulation efficiency, particle morphology, and storage stability. Mouse macrophages (Raw 264.7) and human intestinal cells (Caco-2) were used to assess the effect of the intestinal-digested fraction of the encapsulated kale sprout extracts on the cellular antioxidant capacity, the production of nitric oxide (NOx), and the concentrations of different cytokines as indicators of the immunological response. The highest encapsulation efficiency was observed in capsules with a 50:50 proportion of the hydroalcoholic extract of kale and maltodextrin. Gastrointestinal digestion affected compounds' content in encapsulated and non-encapsulated kale sprouts. Spray-dried encapsulation reduced the phytochemicals' degradation during storage, and the kale sprouts germinated with S and Se showed less degradation of lutein (35.6%, 28.2%), glucosinolates (15.4%, 18.9%), and phenolic compounds (20.3%, 25.7%), compared to non-encapsulated ones, respectively. S-encapsulates exerted the highest cellular antioxidant activity (94.2%) and immunomodulatory activity by stimulating IL-10 production (88.9%) and COX-2 (84.1%) and NOx (92.2%) inhibition. Thus, encapsulation is an effective method to improve kale sprout phytochemicals' stability and bioactivity during storage and metabolism.

Development and optimization of nanoparticles loaded with erucin, a dietary isothiocyanate isolated from Eruca sativa: Antioxidant and antiproliferative activities in ehrlich-ascites carcinoma cell line

The study on Erucin (ER) has gained interest of nutraceutical and pharmaceutical industries because of its anti-cancer properties. Erucin is an isothiocyanate obtained from the seeds of Eruca sativa which possess certain drawbacks such as poor aqueous solubility and bioavailability. Therefore, the present study aimed at developing ER-cubosomes (CUB) by solvent evaporation technique followed by applying Central Composite Design to optimize ER loaded cubosomes. For this purpose, independent variables selected were Monoolein (MO) as lipid and Pluronic-84 (P-84) as a stabilizer whereas dependent variables were particle size, percentage of ER loading and percentage of its entrapment efficiency. The cubosomal nanocarriers exhibited particle size in the range of 26 nm, entrapment efficiency of 99.12 ± 0.04% and drug loading of 3.96 ± 0.0001%. Furthermore, to investigate the antioxidant potential, we checked the effect of ER and ER-CUB by DNA nicking assay, DDPH assay and Phosphomolybdate assay, and results showed significant improvement in antioxidant potential for ER-CUB than ER. Similarly, ER-CUB showed enhanced anticancer activity with a marked reduction in IC50 value than ER in MTT assay. These results suggested that ER-CUB produced notable escalation in antioxidant potential and enhanced anticancer activity than ER.

The recent advances of glucosinolates and their metabolites: Metabolism, physiological functions and potential application strategies

Glucosinolates and their metabolites from Brassicaceae plants have received widespread attention due to their anti-inflammatory effects. Glucosinolates occurs an "enterohepatic circulation" in the body, and the glucosinolates metabolism mainly happens in the intestine. Glucosinolates can be converted into isothiocyanates by intestinal bacteria, which are active substances with remarkable anti-inflammatory, anti-cancer, anti-obesity and neuroprotective properties. This biotransformation can greatly improve the bioactivities of glucosinolates. However, multiple factors in the environment can affect the biotransformation to isothiocyanates, including acidic pH, ferrous ions and thiocyanate-forming protein. The derivatives of glucosinolates under those conditions are usually nitriles and thiocyanates, which may impair the potential health benefits. In addition, isothiocyanates are extremely unstable because of an active sulfhydryl group, which limits their applications. This review mainly summarizes the classification, synthesis, absorption, metabolism, physiological functions and potential application strategies of glucosinolates and their metabolites.

Sulphoraphane Affinity-Based Chromatography for the Purification of Myrosinase from Lepidium sativum Seeds

Sulforaphane and other natural isothiocyanates released from the respective plant glucosinolates by the plant enzyme myrosinase (β-thioglucoside glucohydrolase) show extensive anticancer and antimicrobial effects. In this study, myrosinase from garden cress (Lepidium sativum) seeds was purified to electrophoretic homogeneity by a fast and easy strategy consisting of fractionation by isoelectric precipitation with ammonium sulphate (AS) and affinity chromatography using sulforaphane (SFN) attached to cellulose resin. The overall purification of enzyme with respect to crude extract was 169-fold and recovery of 37%. Under non-reducing conditions, two protein bands exhibiting myrosinase activity with masses of about 114 and 122 kDa, respectively, and a 58 kDa protein band with no activity were detected by SDS-PAGE and zymography on polyacrylamide gel. MALDI-Tof/Tof of tryptic fragments obtained from the respective protein bands detected sequence motifs homologous to the regions responsible for glycoside-substrate binding and similarities to members of the enzyme subfamilies β-glucosidases and myrosinases GH. The enzyme hydrolyzed both the natural (sinigrin, sinalbin, glucoraphanin) and the synthetic (p-nitrophenol-β-D-glucopyranoside (pNPG)) substrates. The highest catalytic activity of purified enzyme was achieved against sinigrin. The K_M and V_max values of the enzyme for sinigrin were found to be 0.57 mM, and 1.3 mM/s, respectively. The enzyme was strongly activated by 30 μM ascorbic acid. The optimum temperature and pH for enzyme was 50 °C and pH 6.0, respectively. The purified enzyme could be stored at 4 °C and slightly acidic pH for at least 45 days without a significant decrease in specific activity.

The Role of Glucosinolates from Cruciferous Vegetables (Brassicaceae) in Gastrointestinal Cancers: From Prevention to Therapeutics

The gastrointestinal (GI) tract is composed of rapidly renewing cells, which increase the likelihood of cancer. Colorectal cancer is one of the most frequently diagnosed GI cancers and currently stands in second place regarding cancer-related mortality. Unfortunately, the treatment of GI is limited, and few developments have occurred in the field over the years. With this in mind, new therapeutic strategies involving biologically active phytocompounds are being evaluated as anti-cancer agents. Vegetables such as broccoli, brussels sprouts, cabbage, cauliflower, and radish, all belonging to the Brassicaceae family, are high in dietary fibre, minerals, vitamins, carotenoids, polyphenols, and glucosinolates. The latter compound is a secondary metabolite characteristic of this family and, when biologically active, has demonstrated anti-cancer properties. This article reviews the literature regarding the potential of Cruciferous vegetables in the prevention and/or treatment of GI cancers and the relevance of appropriate compound formulations for improving the stability and bioaccessibility of the major Cruciferous compounds, with a particular focus on glucosinolates.

Functional and Oxidative Quality Characterization of Spray-Dried Omega-3-Enriched Milk Powder

In the present study, fish oil (FO) and wall material were supplemented to milk to produce spray-dried powder (SDP). Furthermore, the mandate of the study was to enlighten the effect of spray-drying (SD) operating conditions on functional and oxidative quality of produced SDP samples. Purposefully, the cow milk was supplemented with 3% FO as omega-enriched source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for development of milk and FO blends (MFOBs). The lecithin was used as an emulsifier and maltodextrin was supplemented as the wall material (WM) in the MFOBs. Initially, the FO, milk fat (MF), and MFOB samples were characterized for EPA, DHA, and peroxide value (PV) before the SD. The SD of MFOB samples was carried out to produce SDP samples by using a mini spray dryer. Central composite design (CCD) with face-centered rotation was used to optimize SD independent conditions such as inlet air temperature (IAT), pump speed (PS), maltodextrin percentage (MD), and needle speed (NS) in the ranges of 160–200°C, 3–9 mL/min, 10–30%, and 5–9 s, respectively. The encapsulation efficiency (EE) ranged between 89.30 and 81.57%. The EPA and DHA retentions were in the ranges of 2.19–1.87 g/100 g and 3.20–2.75 g/100 g, respectively. The highest results for responses were observed on the following conditions: IAT was 160°C, PS was 9 mL/min, MD was 30%, and NS was 9 s, respectively; the minimum values of response factors were obtained on the following conditions: IAT was 200°C, PS was 3 mL/min, MD was 10%, and NS was 5 s, respectively. The percent losses of EPA and DHA were noted in the range of 2–18%. The IAT was observed as main factor for FA reduction in SDP samples. The SDP samples were stable, and low rate of peroxide values was noted. Overall, spray drying can be potentially used to incorporate the essential fatty acids in milk to produce stable SDP for food applications.

The Influence of Red Cabbage Extract Nanoencapsulated with Brassica Plasma Membrane Vesicles on the Gut Microbiome of Obese Volunteers

The aim of the study was to evaluate the influence of the red cabbage extracts on the bioaccessibility of their isothiocyanates, and their effect on the intestinal microbiota using a dynamic model of human digestion treated with the gut microbiome of obese adults. The elicitation of red cabbage plants with methyl jasmonate (MeJA) duplicated the content of glucosinolates (GSLs) in the plant organs used for elaborating the encapsulated formula. The use of plasma membrane vesicles, according to a proper methodology and technology, showed a high retention of sulforaphane (SFN) and indol-3-carbinol (I3C) over the course of the 14-day digestion study. The microbiome was scarcely affected by the treatments in terms of microbiota composition or the Bacteroidetes/Firmicutes ratio, but a 3 to 4-fold increase was observed in the production of butyric acid with the encapsulated extract treatment. Based on our pilot red cabbage extract study, the consumption of this extract, mainly encapsulated, may play a potential role in the management of obesity in adults.

Approaches for enhancing the stability and formation of sulforaphane

The isothiocyanate sulforaphane (SF) is one of the most potent naturally occurring Phase 2 enzymes inducers derived from brassica vegetables like broccoli, cabbage, brussel sprouts, etc. Ingestion of broccoli releases SF via hydrolysis of glucoraphanin (GRP) by plant myrosinase and/or intestinal microbiota. However, both SF and plant myrosinase are thermal-labile, and the epithiospecifier protein (ESP) directs the hydrolysis of GRP toward formation of sulforaphane nitrile instead of SF. In addition, bacterial myrosinase has low hydrolyzing efficiency. In this review, we discuss strategies that could be employed to improve the stability of SF, increase SF formation during thermal and non-thermal processing of broccoli, and enhance the myrosinase-like activity of the gut microbiota. Furthermore, new cooking methods or blanching technologies should be developed to maintain myrosinase activity, and novel thermostable myrosinase and/or microbes with high SF producing abilities should also be developed.

Development of Prolamin-Based Composite Nanoparticles for Controlled Release of Sulforaphane

Sulforaphane (SFN) has been documented to possess anticancer properties. However, its application is limited by instability and poor bioavailability, which could be enhanced by colloidal delivery systems. In this study, prolamins from two cereal grains, i.e., proso millet (MP) and corn (CP), were extracted and used to fabricate nanoparticles for SFN via an anti-solvent process. A secondary layer with a complex of sodium caseinate (NaCas)/propylene glycol alginate (PGA) at an equal mass was deposited to further improve the stability of nanoparticles. Results indicated that composite nanoparticles with NaCas/PGA at 0.3% (w/v) exhibited a spherical shape with high encapsulation efficiency (>80%), small size (150 nm), and highly negative ζ potential (-39 mV). SFN in MP compared to that in CP showed a similar but lower releasing rate under simulated in vitro digestion. Therefore, prolamins from both sources are promising plant source delivery materials to improve stability and achieve controlled release of bioactives.

Encapsulation of broccoli extract by electrospraying: Influence of in vitro simulated digestion on phenolic and glucosinolate contents, and on antioxidant and antihyperglycemic activities

Compounds present in broccoli are vulnerable to the digestive process, and encapsulation becomes an alternative for their preservation. The encapsulation of broccoli extract, by electrospraying, was performed with the purpose of evaluating the effect of in vitro simulated digestion on individual compounds and antioxidant and antihyperglycemic potentials. Each digestion fraction was evaluated by chromatography, as well as for antioxidant activity and antihyperglycemic potential. The encapsulated extract showed high encapsulation efficiency and spherical morphology. Losses in the levels of phenolic compounds and glucosinolates were found in both extracts, considering the fractions submitted to digestion. The digestion promoted an increase in the inhibition of hydroxyl, nitric oxide and α-amylase, as well as a decrease in the inhibition of α-glucosidase in both extracts, when compared to undigested fractions. Thus, the digestion affects the compounds content in both encapsulated and unencapsulated extracts. However, they still promote the control of oxidative processes and hyperglycemia.

Glucosinolates and phenolic compounds rich broccoli extract: Encapsulation by electrospraying and antitumor activity against glial tumor cells

Gliomas, intracranial malignant tumors, are aggressive, asymptomatic and difficult to treat due to their degree of infiltration, alternatives are needed to treat the disease. In this sense, natural compounds from the specialized metabolism of plants can act to control the disease. Glucosinolates and phenolic compounds, present in broccoli, have a potential to promote tumor cell death, however due to the low stability of these compounds, encapsulation becomes an alternative for their preservation. The objective was to encapsulate the broccoli extract by electrospraying and to evaluate its cytotoxicity in the primary cell culture of astrocytes and gliomas. The capsules were produced and characterized by encapsulation efficiency, functional groups, thermal stability and morphology, the capsule that presented the best parameters was used for the evaluation of cell cytotoxicity and antitumor activity. Capsules with equal or less than 50 % extract showed high encapsulation efficiency, high thermal stability and uniform morphology due to non-saturation of the active zein sites, which allowed a complete encapsulation of the added extract, as well as a greater protection of the compounds. The capsule with 50 % of the extract showed good results of the efficiency, morphology and thermal stability and was used to evaluate the antitumor activity, since the addition of extract in proportions greater than 60 % promoted saturation of the active sites and lower encapsulation efficiency, and directly affects the morphology and thermal stability. The encapsulated and unencapsulated extracts showed strong selective antitumor effect against glial tumor cells without toxicity to non-tumor cells.

Sulforaphane as an anticancer molecule: mechanisms of action, synergistic effects, enhancement of drug safety, and delivery systems

Sulforaphane is an isothiocyanate compound that has been derived from cruciferous vegetables. It was shown in numerous studies to be active against multiple cancer types including pancreatic, prostate, breast, lung, cervical, and colorectal cancers. Sulforaphane exerts its therapeutics action by a variety of mechanisms, such as by detoxifying carcinogens and oxidants through blockage of phase I metabolic enzymes, and by arresting cell cycle in the G2/M and G1 phase to inhibit cell proliferation. The most striking observation was the ability of sulforaphane to potentiate the activity of several classes of anticancer agents including paclitaxel, docetaxel, and gemcitabine through additive and synergistic effects. Although a good number of reviews have reported on the mechanisms by which sulforaphane exerts its anticancer activity, a comprehensive review on the synergistic effect of sulforaphane and its delivery strategies is lacking. Therefore, the aim of the current review was to provide a summary of the studies that have been reported on the activity enhancement effect of sulforaphane in combination with other anticancer therapies. Also provided is a summary of the strategies that have been developed for the delivery of sulforaphane.

Emerging techniques applied to by-products for food fortification

Considering the increasing consumer demand for healthy food, the extract from broccoli by-products was studied. To this aim, in the first step, three extraction techniques were compared in terms of extraction efficiency. The best method was the pressurized liquid extraction. Then, the extract microencapsulation was optimized in terms of type of wall material (between Capsul and maltodextrins), concentration of wall material (10-20-30%, w/v), core/wall material ratio (1:2, 1:5, 1:10, 1:20) and inlet temperature (80, 100, 130, 150, 170 °C). The optimal conditions were found with 10% maltodextrins as wall material, core/wall material ratio 1/2 at 80 °C. Finally, the obtained microencapsulated extract was added at 5% (w/w) to fish burgers. Results demonstrated that total phenolic content, total flavonoids and antioxidant activity of enriched fish products were significantly higher than the control burgers, thus confirming that both process and cooking did not greatly affect the nutritional properties of extracted compounds.

Insights about stabilization of sulforaphane through microencapsulation

The health–promoting properties of sulforaphane (SFN) are well known, however its instability is still a hurdle for its incorporation into food matrices. SFN can be stabilized by microencapsulation, technique sparingly explored for isothiocyanates so far. This review summarizes the advances in microencapsulation of SFN and other isothiocyanates. Encapsulation efficiency and degradation rate of sulforaphane in different systems are compared and discussed. Ionic gelation and complex coacervation seem more adequate for SFN, both underexplored until now. Drying conditions after chemical encapsulation are determinant, most likely related to thermal degradation of SFN. The current information is insufficient to identify the most adequate encapsulation system and the optimal process conditions to stabilize SFN aiming at its incorporation into food matrices. Accordingly, encapsulation conditions should be investigated, which arises as a new research line. Stability studies are encouraged since this information will help in designing SFN microencapsulation strategies that extend the industrial application of this promising health-promoting compound.

Thorough characterization and stability of HP-β-cyclodextrin thymol inclusion complexes prepared by microwave technology: A required approach to a successful application in food industry

BACKGROUND

The aims of the present study were to obtain a stable dry powder formulation of cyclodextrins (CDs) encapsulating thymol, for successful use as an ingredient on an industrial scale, and to characterize the thymol-CDs complexes using different techniques.

RESULTS

Thymol was successfully solubilized in aqueous solutions and the Kc value increased with the pH of the media until the pH was neutral, giving the highest values (2583 ± 176 L mol^-1 ) for HP-β-cyclodextrins (HP-β-CDs). The best encapsulation efficiency of thymol in solid complexes was obtained using the microwave (MWI) encapsulation method. The different characterization techniques have demonstrated the affinity of HP-β-CDs for thymol molecules, forming stable complexes.

CONCLUSIONS

The results support the use of the MWI method in the preparation of solid HP-β-CD-thymol complexes, due to greater encapsulation efficiency and technological and economic advantages for industrial applications. © 2018 Society of Chemical Industry.

Kinetic and thermodynamic studies of sulforaphane adsorption on macroporous resin

The adsorption equilibrium, kinetic and thermodynamic of sulforaphane (SF) adsorption onto macroporous resin in aqueous phase were studied. The SP850 resin was screened as the appropriate resin for SF purification. From the equilibrium studies, the Redlich-Peterson model was found to be the best for description of the adsorption behavior of SF onto SP850 resin, followed by the Freundlich model and the Langmuir model. Batch equilibrium experiments demonstrated that, in the examined temperature range, the equilibrium adsorption capacity of SP850 resin decreased with increasing adsorption temperature. Thermodynamics studies indicated that the adsorption of SF was a physical, exothermic, and spontaneous process. The adsorption kinetics revealed that the pseudo-second-order kinetic model was suitable to characterize the kinetics of adsorption of SF onto SP850. Finally, the intra-particle diffusion model demonstrated that SF diffused quickly into macropores, and that diffusion slowed down in the meso- and micropores.

Sulforaphane delivery using mPEG-PCL co-polymer nanoparticles to breast cancer cells

PURPOSE

Among the potent anticancer agents, d,l-sulforaphane (SF) is very effective against many different types of cancer cells. Its clinical application is restricted because of its hydrophobicity, low gastrointestinal absorption and poor bioavailability. In the present study, a reliable micellar delivery system using monomethoxypoly (ethylene glycol)-poly (ɛ-caprolactone) (mPEG-PCL) was established. The encapsulation of SF inside mPEG-PCL as a nano-carrier was established and the cytotoxicity assay against human breast cancer cell line was evaluated.

METHODS

In this study, SF was encapsulated within mPEG-PCL micelles through a single-step nano-precipitation method, leading to creation of SF-loaded mPEG-PCL (SF/mPEG-PCL) micelles. Di-block mPEG-PCL copolymers were synthesized and used to prepare micelles. MPEG-PCL copolymer was characterized by HNMR, FTIR, differential scanning calorimetry and gel permeation chromatography techniques. Characterization, stability of micelles, the particle size and morphology were determined. The release profile of the SF from the micelles which prepared by the drug-loaded copolymer, was evaluated. The cytotoxicity of free SF, mPEG-PCL and SF-loaded mPEG-PCL micelles was compared with each other by performing MTT assay of the treated MCF-7 cell line. Expression levels of BCL-2, MMP-9, BCL-XL, BAK, BAX and GAPDH (endogenous gene) as control were quantified by real time PCR. To evaluate the apoptotic effects of Free SF compared with SF-loaded mPEG-PCL micelles, flow cytometry analysis was done using the annexin V-FITC apoptosis detection kit.

RESULTS

Our studies resulted in a successful establishment of uniformity and spherical SF-loaded mPEG-PCL micelles. The encapsulation efficiency of SF was 86 ± 1.58%. The results of atomic force microscopy revealed that the micelles have spherical shapes with size of 107 nm. In vitro release of SF from SF-entrapped micelles was remarkably sustained. The mPEG-PCL micelle showed little cytotoxicity in the case of MCF-7 cell line with concentration up to 1.5 mg/ml, whereas the SF-loaded mPEG-PCL micelles at all concentrations significantly was cytotoxic in the case of MCF-7 cell line. Finally, real-time PCR and flow cytometry were used to demonstrate that the SF-loaded mPEG-PCL could be efficiently inducing apoptosis in MCF-7 cell line.

CONCLUSION

We achieved to a successful formulation of SF-loaded m-PEG/PCL micelles in this study. Based on the cytotoxicity results of mPEG-PCL micelles against human breast cancer cell line (MCF-7) in this study, it suggested that SF/mPEG-PCL micelles can be an effective breast cancer treatment strategy in the future.