Preparation and physicochemical characteristics of an allicin nanoliposome and its release behavior

Chitosan-coated nanoliposome: An approach for simultaneous encapsulation of caffeine and roselle-anthocyanin in beverages

The objective of the present research was to develop chitosan-coated nanoliposomes using a modified heating method as a delivery system for simultaneous encapsulation of caffeine and roselle anthocyanin to fortify beverage. Response surface methodology was used to ascertain the optimized formulation, aiming to maximize the encapsulation efficiency, minimize the particle size, and maximize the zeta potential. The liposomes fabricated under the optimized conditions (lecithin to cholesterol ratio of 13 and wall to core ratio of 2.16) showed encapsulation efficiency values of 66.73 % for caffeine and 97.03 % for anthocyanin, with a size of 268.1 nm and a zeta potential of -39.11 mV. Fourier transform infrared spectroscopy confirmed the formation of hydrogen bonds between the polar sites of lecithin and the loaded core compounds. Thermal analysis suggested the successful encapsulation of the caffeine and anthocyanin. Transmission and scanning electron microscopy images confirmed a uniform spherical shape with a smooth surface. Fortifying the model beverage with the liposome and the chitosan-coated nanoliposome revealed higher values of encapsulation efficiency of anthocyanin (70.33 ± 3.11 %), caffeine (86.37 ± 2.17 %) and smaller size (280.5 ± 0.74 nm) of the chitosan-coated nanoliposomes at the end of 60the days. A hedonic sensory test of the fortified beverage with chitosan-coated nanoliposomes confirmed an improvement in the organoleptic properties of the beverage by masking its bitterness (receiving three more sensory scores in perceiving the bitterness intensity). Overall, our study indicates that the high potential of the chitosan-coated nanoliposomes for the simultaneous loading of the caffeine and anthocyanin, as well as their possible application in food and beverage formulations.

Revitalizing allicin for cancer therapy: advances in formulation strategies to enhance bioavailability, stability, and clinical efficacy

The main objective of this review is to highlight the therapeutic potential of allicin, a defense molecule in garlic known for its diverse health benefits, and address the key challenges of its bioavailability and stability. The research further aims to evaluate various formulation strategies and nanotechnology-based delivery systems that can resolve these issues and improve allicin's clinical efficacy, especially in cancer therapy. We conducted a comprehensive review of the available literature and previous studies, focusing on the therapeutic properties of allicin, its bioavailability, stability issues, and novel formulation strategies. We assessed the mechanism of action of allicin in cancer, including its effects on signaling pathways, cell cycle, apoptosis, autophagy, and tumor development. We also evaluated the outcomes of both in vitro and in vivo studies on different types of cancers, such as breast, cervical, colon, lung, and gastric cancer. Despite allicin's significant therapeutic benefits, including cardiovascular, antihypertensive, cholesterol-lowering, antimicrobial, antifungal, anticancer, and immune-modulatory activity, its clinical utility is limited due to poor stability and unpredictable bioavailability. Allicin's bioavailability in the gastrointestinal tract is dependent on the activity of the enzyme alliinase, and its stability can be affected by various conditions like gastric acid and intestinal enzyme proteases. Recent advances in formulation strategies and nanotechnology-based drug delivery systems show promise in addressing these challenges, potentially improving allicin's solubility, stability, and bioavailability. Allicin offers substantial potential for cancer therapy, yet its application is hindered by its instability and poor bioavailability. Novel formulation strategies and nanotechnology-based delivery systems can significantly overcome these limitations, enhancing the therapeutic efficacy of allicin. Future research should focus on refining these formulation strategies and delivery systems, ensuring the safety and efficacy of these new allicin formulations. Clinical trials and long-term studies should be carried out to determine the optimal dosage, assess potential side effects, and evaluate their real-world applicability. The comparative analysis of different drug delivery approaches and the development of targeted delivery systems can also provide further insight into enhancing the therapeutic potential of allicin.

Improvement of the oxidative stability of instant fried noodles using free and microencapsulated borage (Echium amoenum) and black hollyhock (Altaea rosea var nigra) extracts

This study investigated the oxidative stability of instant fried noodles by applying free and microencapsulated black hollyhock extracts (BHE) and borage extracts (BE) (BE, BHE, ME-BE and ME-BHE). At first, the BE and BHE were encapsulated with whey protein and maltodextrin at a 90:10 ratio through a spray dryer. After evaluating particle characteristics (including anthocyanin content, zeta potential, polydispersity index (PDI), particle size, and morphology), they were added to the noodle formulation (wheat flour 78.5%, NaCl 0.78%, and water 21.21%) at 1% w/w level, and the physicochemical (proximate analysis, pH, color, cooking loss, and texture), sensory properties (taste, odor, color, texture, and overall acceptability), and oxidative stability (acid value, peroxide value, anisidine index, thiobarbituric acid index, conjugated dienes) of the fried noodles were studied. The results showed that the microcapsules had uneven shapes with angular surfaces. There was no significant difference between the zeta potential, particle size, PDI, and encapsulation efficiency of BE- and BHE-loaded microcapsules, and the values reported fell between -34.96 and -34.84 mV, 1.128 and 1.195 μm, 0.247 and 0.283, and 80.08% and 83.47%, respectively. Adding extracts to the functional noodles decreased cooking loss and pH compared to the control. The noodles exhibited a darker color. BE and BHE reduced the oxidation of fried noodle oil, with microencapsulated extracts showing stronger effects during storage (p < .05). Sensory evaluation indicated high acceptability for all samples. Encapsulation effectively preserves the natural antioxidant activities of BE and BHE, providing potential benefits for food processing and storage.

Bioavailability, Health Benefits, and Delivery Systems of Allicin: A Review

Garlic has been used worldwide as a spice due to its pungent taste and flavor-enhancing properties. As a main biologically active component of the freshly crushed garlic extracts, allicin (diallyl thiosulfinate) is converted from alliin by alliinase upon damaging the garlic clove, which has been reported to have many potent beneficial biological functions. In this work, allicin formation, stability, bioavailability, and metabolism process are examined and summarized. The biological functions of allicin and potential underlying mechanisms are reviewed and discussed, including antioxidation, anti-inflammation, antidiabetic, cardioprotective, antineurodegenerative, antitumor, and antiobesity effects. Novel delivery systems of allicin with enhanced stability, encapsulation efficiency, and bioavailability are also evaluated, such as nanoparticles, gels, liposomes, and micelles. This study could provide a comprehensive understanding of the physiochemical properties and health benefits of allicin, with great potential for further applications in the food and nutraceutical industries.

Nano-Resveratrol Liposome: Physicochemical Stability, In Vitro Release, and Cytotoxicity

Nano-resveratrol liposome (RES-LIP) was prepared by the thin film rotary-evaporated method combined with ultrasonication and characterized by transmission electron microscopy (TEM), zeta potential, dynamic light scattering (DLS), and Fourier-transform infrared (FT-IR). The physicochemical stability, in vitro release, antioxidant activity, and cytotoxicity of RES-LIP were studied. Data showed that RES-LIP was a spherical vesicle with a diameter of less than 100 nm, the zeta potential was - 60 mV and the encapsulation efficiency was 86.78%. The physicochemical stability of RES-LIP was determined by Ea, ΔG, ΔH, and ΔS, which suggested that the process of RES-LIP degradation was spontaneous and endothermic. The in vitro release of RES-LIP was pH-dependent, belonged to the Weibull model, and was non-Fick diffusion. The antioxidant activity of RES-LIP was stronger than free resveratrol. The MTT assay and flow cytometry results suggested that resveratrol decreased cytotoxicity after being encapsulated by liposome. The prepared RES-LIP had high encapsulation efficiency, was sustained-release, had low cytotoxicity, was pH-targeted, and had potential usage in food and medicine fields.

Allicin, an Emerging Treatment for Pulmonary Arterial Hypertension: An Experimental Study

We assessed whether allicin, through its antihypertensive and antioxidant effects, relieves vascular remodeling, endothelial function, and oxidative stress (OS), thereby improving experimental pulmonary arterial hypertension (PAH). Allicin (16 mg/kg) was administered to rats with PAH (monocrotaline 60 mg/kg). Allicin encouraged body weight gain and survival rate, and medial wall thickness and the right ventricle (RV) hypertrophy were prevented. Also, angiotensin II concentrations in the lung (0.37 ± 0.01 vs. 0.47 ± 0.06 pmoles/mL, allicin and control, respectively) and plasma (0.57 ± 0.05 vs. 0.75 ± 0.064, allicin and control respectively) and the expressions of angiotensin-converting enzyme II and angiotensin II type 1 receptor in lung tissue were maintained at normal control levels with allicin. In PAH rats treated with allicin, nitric oxide (NO) (31.72 ± 1.22 and 51.4 ± 3.45 pmoles/mL), tetrahydrobiopterin (8.43 ± 0.33 and 10.14 ± 0.70 pmoles/mL), cyclic guanosine monophosphate (5.54 ± 0.42 and 5.64 ± 0.73 pmoles/mL), and Ang-(1-7) (0.88 ± 0.23 and 0.83 ± 0.056 pmoles/mL) concentrations increased in lung tissue and plasma, respectively. In contrast, dihydrobiopterin increase was prevented in both lung tissue and plasma (5.75 ± 0.3 and 5.64 ± 0.73 pmoles/mL); meanwhile, phosphodiesterase-5 was maintained at normal levels in lung tissue. OS in PAH was prevented with allicin through the increased expression of Nrf2 in the lung. Allicin prevented the lung response to hypoxia, preventing the overexpression of HIF-1α and VEGF. Allicin attenuated the vascular remodeling and RV hypertrophy in PAH through its effects on NO-dependent vasodilation, modulation of RAS, and amelioration of OS. Also, these effects could be associated with the modulation of HIF-1α and improved lung oxygenation. The global effects of allicin contribute to preventing endothelial dysfunction, remodeling of the pulmonary arteries, and RV hypertrophy, preventing heart failure, thus favoring survival. Although human studies are needed, the data suggest that, alone or in combination therapy, allicin may be an alternative in treating PAH if we consider that, similarly to current treatments, it improves lung vasodilation and increase survival. Allicin may be considered an option when there is a lack of efficacy, and where drug intolerance is observed, to enhance the efficacy of drugs, or when more than one pathogenic mechanism must be addressed.

Cinnamon Oil-Loaded Nanoliposomes with Potent Antibacterial and Antibiofilm Activities

Despite recent scientific advances, the global load of bacterial disease remains high and has been established against a backdrop of increasing antimicrobial resistance. Therefore, there is a pressing need for highly effective and natural antibacterial agents. In the present work, the antibiofilm effect provided by essential oils was evaluated. Of these, cinnamon oil extract showed potent antibacterial and antibiofilm activities against Staphylococcus aureus at an MBEC of 75.0 µg/mL. It was revealed that benzyl alcohol, 2-propenal-3-phenyl, hexadecenoic acid, and oleic acid were the major components of the tested cinnamon oil extract. In addition, the interaction between the cinnamon oil and colistin showed a synergistic effect against S. aureus. Cinnamon oil that had been combined with colistin was encapsulated by liposomes to enhance the essential oil's chemical stability, demonstrating a particle size of 91.67 nm, a PDI of 0.143, a zeta potential of -0.129 mV, and an MBEC of 50.0 µg/mL against Staphylococcus aureus. Scanning electron microscopy was employed to observe the morphological changes in the Staphylococcus aureus biofilm that was treated with the encapsulated cinnamon oil extract/colistin. As a natural and safe option, cinnamon oil exhibited satisfactory antibacterial and antibiofilm performance. The application of liposomes further improved the stability of the antibacterial agents and extended the essential oil release profile.

Silica nanoparticles loaded with caffeic acid to optimize the performance of cassava starch/sodium carboxymethyl cellulose film for meat packaging

Cassava starch/sodium carboxymethyl cellulose (CC) was used as the substrate to create a multipurpose food packaging film, and caffeic acid@silica nanoparticles (C@SNPs) was added. The encapsulation rate of caffeic acid in C@SNPs was 84.7 ± 0.97 %. According to SEM pictures, the nanoparticles were evenly dispersed throughout the film and exhibited good compatibility with the other polymers. C@SNPs was added, which enhanced the physical characteristics of film and decreased its water solubility. The best mechanical and oxygen barrier qualities among them are found in the C@SCC_5:1 film, whose tensile strength rises from 7.17 MPa to 15.44 MPa. The C@SCC_5:1 film has scavenging rates of 95.43 % and 84.67 % against ABTS and DPPH free radicals, respectively, and CA can be released continuously in various food systems. In addition, the antibacterial rate of E. coli O157:H7 and S. aureus of C@SCC_5:1 film in meat was 99.9 %, and it can effectively delay lipid oxidation and pH rise. In conclusion,C@SCC_5:1 film is a new type of antibacterial and antioxidant food packaging material.

Monascus Red Pigment Liposomes: Microstructural Characteristics, Stability, and Anticancer Activity

Monascus red pigments (MRPs), which are a kind of natural colorant produced by Monascus spp., are widely used in the food and health supplements industry but are not very stable during processing and storage. Thus, MRPs were embedded into liposome membranes using a thin-film ultrasonic method to improve stability in this study. Monascus red pigments liposomes (MRPL) exhibited spherical unilamellar vesicles (UV) with particle size, polydispersity indexes (PDI), and zeta potential of 20-200 nm, 0.362 ± 0.023, and -42.37 ± 0.21 mV, respectively. pH, thermal, light, metal ion, storage, and in vitro simulated gastrointestinal digestion stability revealed that, compared with free MRPs, liposomes embedding significantly enhanced the stability of MRPs when exposed to adverse environmental conditions. Furthermore, anticancer assay suggested that MRPL exhibited a stronger inhibitory effect on MKN-28 cells by damaging the integrity of cells, with the IC₅₀ value at 0.57 mg/mL. Overall, MRPLs possess stronger stability in external environment and in vitro simulated digestion with greater anticancer activity, indicating that MRPLs have the potential for promising application in the functional foods and pharmaceutical industries.

Application of Nanoliposomes Containing Nisin and Crocin in Milk

Purpose: This study aimed to investigate the effects of nanoliposomes containing crocin and nisin in milk samples as a food model. Therefore, three formulations were prepared and compared, including (1) milk samples containing free nisin and crocin, (2) samples with nanoliposomes containing nisin and crocin, and (3) nisin and crocin-loaded nanoliposomes coated with chitosan. Methods: In order to find the optimum amount of both bioactives within nanoliposomes, analyses of size, polydispersity index (PDI), zeta potential, and encapsulation efficiency were accomplished. Then, the best formulated nanoliposome was evaluated and compared with a solution containing free bioactives and nanoliposomes coated with chitosan using other experiments, including antioxidant and antibacterial activities, viscosity, colorimetric and bacterial growth. Results: The best nanoliposomal system based on the factors of size, PDI, zeta potential, and encapsulation efficiency was related for the nanocarrier with 4 mg crocin, 4.5 mg nisin, and 40 mg lecithin. Based on the results obtained, both nanoliposome (a*=5.41) and chitosancoated nanoliposome (a*=5.09) solutions could significantly (P<0.05) reduce the redness of milk induced by free bioactives (a*=12.32). However, viscosity of milk in chitosan-coated nanoliposome solution was found to be higher (3.42 cP) than other formulations (viscosity of samples with free bioactives was 1.65 cP and viscosity of samples containing nanoliposome was 1.71 cP). In addition, chitosan-coated nanoliposomes could inhibit the growth of Listeria monocytogenes stronger than other samples. Conclusion: Encapsulation of nisin and crocin in nanoliposomes showed promising results for preserving food safety and quality.

Allicin-Loaded Hydroxyapatite: Enhanced Release, Cytocompatibility, and Antibacterial Properties for Bone Tissue Engineering Applications

Allicin, the active compound of garlic extract, is a naturally sourced biomolecule, which promotes a vast range of health benefits. However, the limited stability of allicin restricts its applications in tissue engineering. Additionally, the detailed effects of allicin in bone health are yet to be explored. Our work reports on the fabrication of a novel allicin-loaded hydroxyapatite drug delivery system with enhanced biological properties. The fabricated system shows excellent antibacterial efficiency against S. aureus after 36 h of bacterial interaction with a sample. The allicin release kinetics are enhanced with polycaprolactone (PCL). The obtained results after 20 days of drug release study indicate that PCL coating leads to an increase in cumulative allicin release from ~ 35% to 70% at a physiological pH of 7.4. These scaffolds maintain stability during the whole period of drug release. Cytocompatibility of tested compositions with osteoblasts indicates enhanced cell viability and good filopodial attachment on the sample surface at day 7. These allicin-loaded antibacterial and cytocompatible scaffolds can find applications as localized delivery vehicles for bone tissue engineering.

Cellular Mechanisms Underlying the Cardioprotective Role of Allicin on Cardiovascular Diseases

Cardiovascular diseases (CVDs) are a group of diseases in which the common denominator is the affection of blood vessels, heart tissue, and heart rhythm. The genesis of CVD is complex and multifactorial; therefore, approaches are often based on multidisciplinary management and more than one drug is used to achieve the optimal control of risk factors (dyslipidemia, hypertension, hypertrophy, oxidative stress, endothelial dysfunction, inflammation). In this context, allicin, a sulfur compound naturally derived from garlic, has shown beneficial effects on several cardiovascular risk factors through the modulation of cellular mechanisms and signaling pathways. Effective pharmacological treatments for CVD or its risk factors have not been developed or are unknown in clinical practice. Thus, this work aimed to review the cellular mechanisms through which allicin exerts its therapeutic effects and to show why it could be a therapeutic option for the prevention or treatment of CVD and its risk factors.

Development of Biodegradable/Biocompatible Nanoliposome-Encapsulated Antimicrobial Essential Oils for Topical Creams and Gels

Nanoencapsulation with safe materials improves delivery, stability, and activity of bioactive components. We report a novel safe, and effective method for the development of encapsulated antimicrobial essential oils (EO) for topical creams and gels. The method developed features three aspects that, to our knowledge, had not been previously demonstrated: (1) use of novel liposomes (LPs) to encapsulate EOs, (2) use of the EOs to replace synthetic organic solvents that are potentially toxic and/or leave harmful residues, and (3) an encapsulation process at temperatures below the boiling point of water. The LPs were made from soy lecithin, phytosterol, and α-tocopherol (vitamin E) that were synthesized using the EOs as the solvent. The liposomes were converted to nanoliposomes (NLPs) through a series of sonication, homogenization, and extrusion steps. Transmission electron microscopy indicated that the NLPs alone and nanoliposome encapsulated EOs (NLP-EOs) were spherical in shape with sizes ranging between 50 and 115 nm diameter and with negative zeta potentials ranging from -34 to -43 mV. There was no significant heavy metal contamination [As, Pb, Cd, Hg] based on inductively coupled plasma (ICP) mass spectrometry MS analyses. Nearly complete EO encapsulation (95% encapsulation efficiency) was achieved and confirmed by GC/MS. Three of the NLP-EOs made of various essential oils were used to make topical formulations (cream and gel) which exhibited antimicrobial activities against Escherichia coli (Gram negative) and Bacillus subtilis (Gram positive) bacteria. The creams with NLP-EOs were as active against the two bacteria in the antimicrobial assays as the conventional antibiotic Kanamycin that was used as positive control.

Nanoliposomal formulation of pistachio hull extract: preparation, characterization and anti-cancer evaluation through Bax/Bcl2 modulation

BACKGROUND

Pistachio is one of the main crops in Iran. Pistachio green hull, as a by-product of this fruit, is obtained in large quantities after the processing of pistachios. This novel work was designed to examine the possible anti-cancer impact of the pistachio hull extract in the liposomal form (PHEL) on HepG2 cells.

METHODS AND RESULTS

The thin-film hydration approach was used for preparing liposomes and the physicochemical features of the liposomes were subsequently characterized. Afterward, apoptosis and the expression of genes related to apoptosis were assessed using flow cytometry assay and quantitative real-time polymerase chain reaction (qPCR), respectively. According to the results, the size range of PHEL was between 198 and 201 nm with a negative surface charge of - 39.2 to - 42.9 mV. As revealed by the flow cytometry results, this liposomal extract exhibits good potential for the induction of apoptosis. Moreover, the qPCR results demonstrated the up-regulation of p53 and Bax expressions and the down-regulation of Bcl-2 expression with an associated Bax/Bcl-2 ratio up-regulation.

CONCLUSION

The flow cytometry and real-time PCR results indicated the potential of this liposomal extract as an anti-cancer drug candidate for the treatment of liver cancer in the future, and the mitochondrial pathway involving the up-regulation of the Bax/Bcl-2 ratio can mediate its impact.

Spirulina platensis extract nanoliposomes: preparation, characterization and application to white cheese

BACKGROUND

Ultrafiltration cheese is produced in large scale from treated and pasteurized treated and pasteurized milk with mesophilic starter and to expand its shelf life preservatives addition is needed.

OBJECTIVE

The purpose of the present study was preparation of encapsulate Spirulina platensis algae nanoliposomes to evaluate the characteristics of the nanoliposomes loaded with Spirulina extract (SE-NLs). In addition, the chemical and microbiological properties of white cheese produced with SE-NLs were studied.

METHODS

Nanoliposomes are composed of lecithin and cholesterol, used for the encapsulation of SE. The SE-NLs were prepared using the thin layer hydration method. The characteristics of produced SE-NLs including particle size, zeta potential, morphology and the encapsulation efficiency (EE) was studied during 4 weeks in different storage conditions (4 °C and 25 °C). In addition, the effect of SE and SE-NLs on the chemical and microbiological properties of white cheese was evaluated during 60 days of ripening.

RESULTS

The results showed that the nanoliposomes loaded with 3 mg/g of SE had the optimum formulation due to the higher EE, smaller particle size, and higher negatively charged zeta potential. The quality of the produced nanoliposomes decreased by increasing the time of storage but the SE-NLs stored at 4 °C were more stable and possessed higher EE and smaller particle sizes. While the chemical composition of the cheeses manufactured by the nanoliposome loaded with 3 mg/g SE- NLs were comparable to that of control cheese at 60 days of ripening, it showed a significant inhibitory effect on Staphylococcus aureus and Listeria monocytogenes after 30 days.

CONCLUSION

The utilization of SE-NLs can be considered as a natural antimicrobial and an alternative to the use of synthetic preservatives in the production of white cheese.

HIGHLIGHTS

Nanoliposomes of Spirulina platensis extracts was prepared.UF white cheese prepared by nanoliposomes and then were evaluated.

Pleurotus eryngii polysaccharide nanofiber containing pomegranate peel polyphenol/chitosan nanoparticles for control of E. coli O157:H7

Pomegranate peel polyphenols (PPP), which are natural, safe, and green antibacterial agents, were introduced and embedded in chitosan to form stable nanoparticles. The PPP@chitosan nanoparticles (PPP@CNPs) were further electrospun into nanofibers based on Pleurotus eryngii polysaccharide (PEP). The preferable distribution of particle size, polydispersity index, and zeta potential was realized through the addition of PPP at 3 mg/mL, which achieved the highest encapsulation rate of 23.71 ± 0.51%. The tensile strength and elongation at break of nanofibers reached 15.76 MPa and 0.69% with the addition of 1% PEP through electrospinning. The results of scanning electron microscopy (SEM) and atomic force microscopy (AFM) demonstrated that the addition of nanoparticles increased the diameter of PEP nanofibers from 148 nm to 163 nm, and the surface roughness of the fibers also increased. Meanwhile, the addition of nanoparticles improved the thermal stability of PEP nanofibers. PPP@CNPs/PEP nanofibers can inhibit the growth of E. coli O157:H7 on pork and cucumber surfaces during the five-days storage, and the inhibition rates were all above 95%. Besides, the nanofibers did not have any impact on the color and texture of foods.

Carvacrol-loaded liposome suspension: optimization, characterization and incorporation into poly(vinyl alcohol) films

The purpose of this study was to encapsulate carvacrol into liposomes in order to promote its application in active food packaging. Response surface methodology was used to evaluate the effect of the concentration of the liposomal components on its characteristics. The optimum formulation for the preparation of liposomes with the highest encapsulation efficiency (59.0 ± 1.99%) was found to be 3000 μg mL^-1 of cholesterol and 4000 μg mL^-1 of carvacrol. Carvacrol reduced the polydispersity index and increased the zeta potential and the thermal stability of liposomes. Fourier-transform infrared spectroscopy indicated that the interaction of carvacrol with liposomes occurred probably through hydrogen-bonding. The incorporation into liposomes maintained the antibacterial effect of carvacrol, but when in the film, carvacrol liposomes were not effective against the microorganisms tested. Liposomes may offer a viable option for stabilizing carvacrol, however, more studies are necessary to enable its application in food packaging.

Allicin and Digestive System Cancers: From Chemical Structure to Its Therapeutic Opportunities

Digestive system cancer tumors are one of the major causes of cancer-related fatalities; the vast majority of them are colorectal or gastric malignancies. Epidemiological evidence confirmed that allium-containing food, such as garlic, reduces the risk of developing malignancies. Among all compounds in garlic, allicin has been most researched, as it contains sulfur and produces many second degradation compounds, such as sulfur dioxide, diallyl sulfide (DAS), diallyl trisulfide (DATS), and diallyl disulfide (DADS) in the presence of enzymatic reactions in gastric juice. These substances have shown anti-inflammatory, antidiabetic, antihypertensive, antifungal, antiviral, antibacterial, and anticancer efficacy, including gastrointestinal (GI) cancers, leukemia, and skin cancers. Herein, we summarize the therapeutic potential of allicin in the treatment of GI cancers.

Ethnobotany and the Role of Plant Natural Products in Antibiotic Drug Discovery

The crisis of antibiotic resistance necessitates creative and innovative approaches, from chemical identification and analysis to the assessment of bioactivity. Plant natural products (NPs) represent a promising source of antibacterial lead compounds that could help fill the drug discovery pipeline in response to the growing antibiotic resistance crisis. The major strength of plant NPs lies in their rich and unique chemodiversity, their worldwide distribution and ease of access, their various antibacterial modes of action, and the proven clinical effectiveness of plant extracts from which they are isolated. While many studies have tried to summarize NPs with antibacterial activities, a comprehensive review with rigorous selection criteria has never been performed. In this work, the literature from 2012 to 2019 was systematically reviewed to highlight plant-derived compounds with antibacterial activity by focusing on their growth inhibitory activity. A total of 459 compounds are included in this Review, of which 50.8% are phenolic derivatives, 26.6% are terpenoids, 5.7% are alkaloids, and 17% are classified as other metabolites. A selection of 183 compounds is further discussed regarding their antibacterial activity, biosynthesis, structure-activity relationship, mechanism of action, and potential as antibiotics. Emerging trends in the field of antibacterial drug discovery from plants are also discussed. This Review brings to the forefront key findings on the antibacterial potential of plant NPs for consideration in future antibiotic discovery and development efforts.

Liposomal Encapsulation of Carvacrol to Obtain Active Poly (Vinyl Alcohol) Films

Lecithins of different origins and compositions were used for the liposomal encapsulation of carvacrol within the framework of the development of active films for food packaging. Liposomes were incorporated into aqueous polymeric solutions from fully (F) and partially (P) hydrolysed Poly (vinyl alcohol) (PVA) to obtain the films by casting. The particle size distribution and ζ-potential of the liposomal suspensions, as well as their stability over time, were evaluated. Liposomal stability during film formation was analysed through the carvacrol retention in the dried film and the film microstructure. Subtle variations in the size distributions of liposomes from different lecithins were observed. However, the absolute values of the ζ-potential were higher (−52, −57 mV) for soy lecithin (SL) liposomes, followed by those of soy lecithin enriched with phosphatidylcholine (SL-PC) (−43, −50 mV) and sunflower lecithin (SFL) (−33, −38 mV). No significant changes in the liposomal properties were observed during the study period. Lyotropic mesomorphism of lipid associations and carvacrol leakage occurred to differing extents during the film drying step, depending on the membrane lipid composition and surface charge. Liposomes obtained with SL-PC were the most effective at maintaining the stability of carvacrol emulsion during film formation, which led to the greatest carvacrol retention in the films, whereas SFL gave rise to the least stable system and the highest carvacrol losses. P-PVA was less sensitive to the emulsion destabilisation due to its greater bonding capacity with carvacrol. Therefore, P-PVA with carvacrol-loaded SL-PC liposomes has great potential to produce active films for food packaging applications.

Encapsulation of Berberis vulgaris Anthocyanins into Nanoliposome Composed of Rapeseed Lecithin: A Comprehensive Study on Physicochemical Characteristics and Biocompatibility

In the present study, nanoliposomes composed of rapeseed lecithin were used for the encapsulation of anthocyanin compounds (AC). The nanoliposomes were prepared using hydration and ultrasound combined method, and the effect of AC concentration (4.5, 6.75, 9% w/w) on the characteristics of nanoliposomes including particle size, polydispersity index (PDI), zeta potential, and the encapsulation efficiency (EE) of nanoliposomes with and without AC were studied. The results suggested the fabricated nanoliposomes had a size range of 141-196 nm, negative zeta potential and narrow particle size distribution. Further, the samples containing 9% extract had the maximum EE (43%). The results showed elevation of AC concentration resulted in increased particle size, PDI, EE, and surface charge of nanoparticles. The presence of AC extract led to diminished membrane fluidity through the hydrophobic interactions with the hydrocarbon chain of fatty acids. TEM images suggested that the nanoliposomes were nearly spherical and the AC caused their improved sphericity. Further, in vitro biocompatibility tests for human mesenchymal (MSC) and fibroblast (FBL) cells indicated nanoparticles were not toxic. Specifically, the best formulations with the maximum compatibility and bioavailability for MSC and FBL cells were AC-loaded nanoliposomes with concentrations of 0.5 mL/mg and 10.3 mL/µg and, respectively.

Plant-Derived Natural Products in Cancer Research: Extraction, Mechanism of Action, and Drug Formulation

Cancer is one of the main causes of death globally and considered as a major challenge for the public health system. The high toxicity and the lack of selectivity of conventional anticancer therapies make the search for alternative treatments a priority. In this review, we describe the main plant-derived natural products used as anticancer agents. Natural sources, extraction methods, anticancer mechanisms, clinical studies, and pharmaceutical formulation are discussed in this review. Studies covered by this review should provide a solid foundation for researchers and physicians to enhance basic and clinical research on developing alternative anticancer therapies.

Cinnamic acid decreases periodontal inflammation and alveolar bone loss in experimental periodontitis

BACKGROUND AND OBJECTIVE

Periodontitis is the chronic destructive disease of the periodontium, which causes severe inflammation in the tissues. Cinnamic acid as an unsaturated carboxylic acid might prevent inflammation and periodontal destruction. The present study aimed to evaluate the effects of cinnamic acid in two different forms as free cinnamic acid and cinnamic acid liposome on experimental periodontitis in Wistar rats.

METHODS

Thirty-two female rats were used in the present study. Four main groups were created as follows: C: control group; P: periodontitis group; C-P: free cinnamic acid-administered periodontitis group; and CL-P: cinnamic acid liposome applied group. Periodontitis was induced via ligating 4-0 silk sutures around lower first molar teeth on both right and left mandibles. The study duration was 30 days, and the ligatures were removed from half of the rats in the periodontitis-induced groups. The other half carried the ligatures throughout 30 days, and all rats were euthanized at 30th day. Mandibles were removed and evaluated via stereomicroscope and underwent histological procedures. Inflammatory cell counts, osteoblast, and osteoclast cell counts were determined in hematoxylin-eosin-stained slides, and peroxisome proliferator-activated receptor (PPAR)-γ, cyclooxygenase (COX)-2, receptor activator of nuclear factor κ-B (RANKL), and osteoprotegerin (OPG) expressions were evaluated by immunohistochemistry.

RESULTS

Control group had the lowest bone loss, and periodontitis group which kept ligatures had the highest bone loss compared to the other groups. Ligature removal provided significant improvement in bone measurements. Cinnamic acid groups also showed lower bone loss compared to the periodontitis group. The inflammatory cell and osteoclast counts were also higher in the periodontitis group, and both applications of cinnamic acid decreased these values. Osteoblast cells were the lowest in the periodontitis group, and cinnamic acid increased these counts. PPAR-γ and COX-2 levels were higher in the periodontitis group, and cinnamic acid decreased these levels but not to a significant level except for the cinnamic acid liposome ligature removal group, which had significantly lower values in the PPAR-γ and COX-2. OPG levels were lower in the periodontitis group compared to the other groups. Cinnamic acid significantly decreased RANKL and increased OPG levels.

CONCLUSION

Periodontitis caused increased inflammation and bone destruction accompanied by increased PPAR-γ, COX-2, and RANKL levels and osteoclast counts. Cinnamic acid decreased osteoclast counts and inflammation and increased osteoblast counts and OPG expression in the present animal model of periodontitis.

Delivery of phytochemicals by liposome cargos: recent progress, challenges and opportunities

Bio-availability is a major concern in delivery of dietary phytochemicals for better bio-efficacy. The reduced bio-availability of food bioactive compounds is evident due to degradation during human digestion process which involves liberation, absorption, distribution, metabolism and elimination. The bio-efficacy of any nutrient can be increased by increasing bio-availability. Different technologies are available for engineered efficient delivery systems; still many challenges remain with advancement of delivery systems. The ease of preparedness and adaptability of liposomes has resulted in wide-range of applicability and acceptability in scientific field, especially as delivery vehicles. In view, of properties like biocompatibility and biodegradability, liposomes have been modified with different usable methodologies for delivery of phytochemicals. The aim of this review is to abridge liposomes, methods of preparation, their application as delivery cargo in dietary phytochemicals, result of using different preparation techniques on properties.

Antifungal properties of phosphatidylcholine-oleic acid liposomes encapsulating garlic against environmental fungal in wheat bread

Liposomes have gained great interest in the food and pharmaceutical industry as colloidal carriers of bioactive compounds. In this work, liposomes of phosphatidylcholine (PC) and oleic acid (OA) encapsulating garlic extract (GE) were developed to determine its aptitude as antifungal agent in wheat bread. The influence of GE on the properties of liposomes were followed by determination of size, Zeta potential, Fourier transform infrared patterns (FTIR), morphology, differential scanning calorimetry (DSC) and thermogravimetric (TGA) techniques. The produced PC-OA-GE liposomes showed spherical morphology with narrow size distribution, entrapment efficiency of 79.7% and zeta potential of -27.9 mV. In vitro antifungal test showed noticeable inhibitory activities for free and encapsulated GE against selected fungal strains. TGA analysis revealed that the presence of OA and GE in the formulation retards the liposomal thermal decomposition, as compared with the pure PC liposomes and the DSC enthalpy and main transition temperature variation in PC-OA-GE liposomes suggested a strong heat-induced rigidifying effect that could be attributed to the presence of garlic polysaccharides in the liposome surface, observed by FTIR. In the in situ test, the bread formulations with free or liposome-encapsulated GE (0.65 mL/100 g of dough) were microbiologically more stable as compared with the controls, showing mold inhibition for five days. Therefore, liposomes formulated with OA and GE showed potential as natural antifungal agent in bakery products.

Co-Encapsulation of EGCG and Quercetin in Liposomes for Optimum Antioxidant Activity

Although different delivery systems have been developed to overcome the limits of Epigallocatechin-3-gallate (EGCG) and quercetin in food application, none have referred to their simultaneous encapsulation. In this study, these two polyphenols were successfully co-loaded into liposomes. Under the optimal conditions (lecithin-total polyphenols ratio 25:1, lecithin-cholesterol ratio 6:1, lecithin-Tween 80 ratio 8:1 and ultrasonic time 2 min), the mean size, polydispersity index (PDI) and zeta potential of liposomes were 111.10 ± 0.52 nm, 0.259 ± 0.006 and -19.83 ± 0.45 mV, with an encapsulation efficiency of 64.05 ± 1.56% and 61.73 ± 2.55% for EGCG and quercetin, respectively. After 30-day storage, an increase of 4.05% was observed in the mean size with no significant change (P ≥ 0.05) in the PDI and zeta potential. Moreover, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay revealed a synergistic antioxidant effect of the two compounds in liposomal system. These results demonstrated that co-encapsulation of EGCG and quercetin enhances their effectiveness. PRACTICAL APPLICATION: EGCG and quercetin are natural polyphenols abound in the human diet with diverse biological activities. These two polyphenols were successfully co-encapsulated into a homogeneous and stable liposomal system. Interestingly, a synergistic antioxidant effect of the two polyphenols was observed due to co-encapsulation. This indicated that the simultaneous delivery of EGCG and quercetin was an attractive approach to improve their functionality for expanding their application in food, cosmetic and pharmaceutical industries.

Encapsulations of wild garlic (Allium ursinum L.) extract using spray congealing technology

The objective of this study was to incorporate wild garlic (A. ursinum) extract into microparticles (MPs) in order to protect its valuable active compounds and improve its oral bioavailability. For this purpose, spray congealing technology was applied and Gelucire 50/13 (Stearoyl polyoxyl-32 glycerides) was selected as MPs carrier. MPs were characterized in terms of yield, encapsulation efficiency and particle size. Differential scanning calorimetry (DSC) and Fourier-transform infrared spectroscopy (FT-IR) analysis of MPs showed the absence of chemical interactions between carrier and extract and suggested that spray congealing process did not modify nor degrade the encapsulated extract. The encapsulation into MPs led to an improvement of the extract dissolution performance as well as an enhancement in solubility of >18 fold compared to the pure extract. Additionally, MPs were stable over three months showing only a minor decrease in the content of active compounds (allicin and S-methyl methanethiosulfonate) and maintaining a good antimicrobial activity. Therefore, obtained results suggested that the encapsulation of A. ursinum extract in MPs by spray congealing is a promising approach to improve the biopharmaceutical properties of the extract, without affecting its antibacterial activity.

Co-loaded proteinase K/thyme oil liposomes for inactivation of Escherichia coli O157:H7 biofilms on cucumber

E. coli O157:H7 is a bacterium frequently found on vegetable surfaces, such as cucumber, that can pose a significant threat to consumers. In the present work, proteinase K (PK) and thyme oil (TO) were used to inactivate E. coli O157:H7 biofilms. Both PK and TO were encapsulated in liposomes to improve their chemical stability and to allow for a controlled release. The optimal PK/TO-loaded liposomes (particle size of 170.4 nm, polydispersity index of 0.309, zeta potential of -29.8 mV and entrapment efficiency of 33.2%) were engineered. The antibacterial activities of the PK/TO liposomes against E. coli O157:H7 biofilms in vitro and on the cucumber were observed. Compared to free PK, free TO, and free PK/TO and TO liposome treatments, PK/TO-liposomes exhibited a higher antibiofilm activity and longer action duration. Specifically, the counts of viable E. coli O157:H7 on cucumbers were reduced by 1.23, 2.32 and 2.44 Logs after treatment with 400 mg mL^-1 of PK/TO liposomes for 3 d, at 5, 15 and 25 °C, respectively. Colorimetric analysis and sensory tests showed that the PK/TO-liposome treatment had almost no impact on food quality after 1 d.