Different molecular organization of two carotenoids, lutein and zeaxanthin, in human colon epithelial cells and colon adenocarcinoma cells

Bioactive substances of cyanobacteria and microalgae: Sources, metabolism, and anticancer mechanism insights

Cyanobacteria and microalgae contain various phytochemicals, including bioactive components in the form of secondary metabolites, namely flavonoids, phenolic acids, terpenoids, and tannins, with remarkable anticancer effects. This review highlights the recent advances in bioactive compounds, with potential anticancer activity, produced by cyanobacteria and microalgae. Previous in vitro investigations showed that many of these bioactive compounds exhibit potent effects against different human cancer types, such as leukemia and breast cancers. Multiple mechanisms implicated in the antitumor effect of these compounds were elucidated, including their ability to target cellular, subcellular, and molecular checkpoints linked to cancer development and promotion. Recent findings have highlighted various mechanisms of action of bioactive compounds produced by cyanobacteria and microalgae, including induction of autophagy and apoptosis, inhibition of telomerase and protein kinases, as well as modulation of epigenetic modifications. In vivo investigations have demonstrated a potent anti-angiogenesis effect on solid tumors, as well as a reduction in tumor volume. Some of these compounds were examined in clinical investigations for certain types of cancers, making them potent candidates/scaffolds for antitumor drug development.

Nanoscale Phytosomes as an Emerging Modality for Cancer Therapy

Extracellular vesicle (EV) research has expanded substantially over the years. EVs have been identified in all living organisms and are produced and released as a means of intercellular communication or as a defense mechanism. Recently, nano-scaled vesicles were successfully isolated from edible plant sources. Plant-derived EVs, referred to here as phytosomes, are of a size reported to range between 30 nm and 120 nm in diameter, similar to small mammalian extracellular vesicles, and carry various bioactive molecules such as mRNA, proteins, miRNA and lipids. Due to the availability of many plants, phytosomes can be easily isolated on a large scale. The methods developed for EV isolation from mammalian cells have been successfully applied for isolation and purification of phytosomes. The therapeutic effects of phytosomes on different disease models, such as inflammation and autoimmune disease, have been reported, and a handful of studies have suggested their therapeutic effects on cancer diseases. Overall, the research on phytosomes is still in its infancy and requires more exploration. This review will narrate the anti-cancer activity and characteristics of phytosomes derived from edible plants as well as describe studies which have utilized phytosomes as drug delivery vehicles for cancer with the ultimate objective of significantly reducing the adverse effects associated with conventional therapeutic approaches.

Associations of serum carotenoids with the severity of sunburn and the risk of cancer: A cross-sectional analysis of 1999-2018 NHANES data

Background

Sunburn is a common problem for outdoor workers and casual outdoor walkers. Carotenoids are important elements in normal function of skin tissue and skin metabolism and are critical in the development of some cancers. However, the possible relationships between sunburn sensitivity, carotenoids and the risk of cancers remain unknown.

Objectives

To explore the associations of serum carotenoids with sunburn severity and the risk of cancers.

Methods

A cross-sectional study from the National Health and Nutrition Examination Survey from 1999 to 2018 were conducted. The relationship between sunburn and serum carotenoids, cancers were investigated by unconditional or ordinal logistic regression. Mediation analysis was used to explore the effect of carotenoids on the relationship between sunburn and cancers.

Results

A total of 25,440 US adults from 1999 to 2018 were enrolled in this study. There were significant differences in sex, race and natural hair color between the sunburn and non-sunburn people. The severity of sunburn was significantly associated with serum trans-β-carotene, cis-β-carotene, combined lutein, and vitamin A. The odds ratios of severe reactions were 5.065 (95% CI: 2.266-11.318) in melanoma patients, 5.776 (95% CI: 3.362-9.922) in non-melanoma patients, and 1.880 (95% CI: 1.484-2.380) in non-skin cancers patients. Additionally, serum carotenoids were partially attributable to the effect of sunburn on skin and non-skin cancers.

Conclusion

Sunburn severity was associated with cancers, and severer sunburn was related with higher risk of cancers. Serum carotenoids were also associated with sunburn severity. Moreover, the relationship between sunburn and cancers was mediated by some serum carotenoids.

Surface modified porous silicon with chitosan coating as a pH-responsive controlled delivery system for lutein

Surface modified pH-responsive porous silicon (PSi) carriers were developed for efficient delivery of lutein. PSi particles were prepared by the electrochemical etching method and modified with two chemical groups: hydroxyl and octadecyl silane, respectively. Chitosan (CS) was used for coating of PSi to ensure pH-responsive release. The loading conditions, release properties, cytotoxicity and toxicity were investigated. The highest loading percentage of lutein could be obtained with oxidized PSi and the structure of the microparticles was characterized by Fourier transform-infrared spectroscopy. The surface area and pore size of the microparticles were obtained from the N₂ adsorption-desorption isotherm. The CS-PSi-Lut microparticles showed the minimum surface area of 220.30 m² g^-1 and a relatively larger average pore width of 179.00 Å. In vitro release experiments showed a pH-responsive and controlled release of lutein, with the fastest release rate and highest cumulative release rate of 97% under acidic conditions (pH 5.0) within 7 h. PSi, chitosan and lutein showed synergistic toxic effects, and the CS-PSi-Lut microparticles could effectively inhibit the proliferation of HT-29 cells in a dose-dependent manner, with an inhibition rate of 77% when the lutein concentration reached 40 μg mL^-1. The in vivo toxicological evaluation of CS-PSi-Lut microparticles indicated good biocompatibility in the range of experimental doses. The chitosan-coated oxidized PSi capable of delivering bioactive compounds in a targeted and controlled manner provides a novel platform for the development and application of lutein.

Development of nanoparticles derived from corn as mass producible bionanoparticles with anticancer activity

Recent studies showed that plant-derived nanoparticles (NPs) can be easily produced in high yields and have potential applications as therapeutic agents or delivery carriers for bioactive molecules. In this study, we selected corn as it is inexpensive to grow and mass-produced globally. Super sweet corn was homogenized in water to obtain corn juice, which was then centrifuged, filtered through a 0.45-μm-pore size syringe filter, and ultracentrifuged to obtain NPs derived from corn, or corn-derived NPs (cNPs). cNPs obtained were approximately 80 nm in diameter and negatively charged (- 17 mV). cNPs were taken up by various types of cells, including colon26 tumor cells and RAW264.7 macrophage-like cells, with selective reduction of the proliferation of colon26 cells. Moreover, cNPs induced tumor necrosis factor-α release from RAW264.7 cells. cNPs and RAW264.7 in combination significantly suppressed the proliferation of colon26/fluc cells. Daily intratumoral injections of cNPs significantly suppressed the growth of subcutaneous colon26 tumors in mice, with no significant body weight loss. These results indicate excellent anti-tumor activity of cNPs.

Anti-Inflammatory and Anticancer Effects of Microalgal Carotenoids

Acute inflammation is a key component of the immune system's response to pathogens, toxic agents, or tissue injury, involving the stimulation of defense mechanisms aimed to removing pathogenic factors and restoring tissue homeostasis. However, uncontrolled acute inflammatory response may lead to chronic inflammation, which is involved in the development of many diseases, including cancer. Nowadays, the need to find new potential therapeutic compounds has raised the worldwide scientific interest to study the marine environment. Specifically, microalgae are considered rich sources of bioactive molecules, such as carotenoids, which are natural isoprenoid pigments with important beneficial effects for health due to their biological activities. Carotenoids are essential nutrients for mammals, but they are unable to synthesize them; instead, a dietary intake of these compounds is required. Carotenoids are classified as carotenes (hydrocarbon carotenoids), such as α- and β-carotene, and xanthophylls (oxygenate derivatives) including zeaxanthin, astaxanthin, fucoxanthin, lutein, α- and β-cryptoxanthin, and canthaxanthin. This review summarizes the present up-to-date knowledge of the anti-inflammatory and anticancer activities of microalgal carotenoids both in vitro and in vivo, as well as the latest status of human studies for their potential use in prevention and treatment of inflammatory diseases and cancer.

Avocado oil: Production and market demand, bioactive components, implications in health, and tendencies and potential uses

Avocado is a subtropical/tropical fruit with creamy texture, peculiar flavor, and high nutritional value. Due to its high oil content, a significant quantity of avocado fruit is used for the production of oil using different methods. Avocado oil is rich in lipid-soluble bioactive compounds, but their content depends on different factors. Several phytochemicals in the oil have been linked to prevention of cancer, age-related macular degeneration, and cardiovascular diseases and therefore have generated an increase in consumer demand for avocado oil. The aim of this review is to critically and systematically analyze the worldwide production and commercialization of avocado oil, its extraction methods, changes in its fat-soluble phytochemical content, health benefits, and new trends and applications. There is a lack of information on the production and commercialization of the different types of avocado oil, but there are abundant data on extraction methods using solvents, centrifugation-assisted aqueous extraction, mechanical extraction by cold pressing (varying concentration and type of enzymes, temperature and time of reaction, and dilution ratio), ultrasound-assisted extraction, and supercritical fluid to enhance the yield and quality of oil. Extensive information is available on the content of fatty acids, although it is limited on carotenoids and chlorophylls. The effect of avocado oil on cancer, diabetes, and cardiovascular diseases has been demonstrated through in vitro and animal studies, but not in humans. Avocado oil continues to be of interest to the food, pharmaceutical, and cosmetic industries and is also generating increased attention in other areas including structured lipids, nanotechnology, and environmental care.

A Comprehensive Overview of Colon Cancer- A Grim Reaper of the 21st Century

A few decades ago, the incidence of colorectal cancer (CRC) was low and is now the fourth in the list of deadly cancers producing nearly a million deaths annually. A population that is aging along with risk factors such as smoking, obesity, sedentary lifestyle with little or no physical activity, and non-healthy food habits of developed countries can increase the risk of colorectal cancer. The balance in gut microbiota and the metabolites produced during bacterial fermentation within the host plays a significant role in regulating intestinal diseases as well as colorectal cancer development. Recent progress in the understanding of illness resulted in multiple treatment options such as surgery, radiation, and chemotherapy, including targeted therapy and multitherapies. The treatment plan for CRC depends on the location, stage and grade of cancer as well as genomic biomarker tests. Despite all the advancements made in the genetic and molecular aspects of the disease, the knowledge seems inadequate as the drug action as well as the wide variation in drug response did not appear strongly correlated with the individual molecular and genetic characteristics, which suggests the requirement of comprehensive molecular understanding of this complex heterogeneous disease. Furthermore, multitherapies or a broad spectrum approach, which is an amalgamation of the various promising as well as effective therapeutic strategies that can tackle heterogeneity and act on several targets of the disease, need to be validated in clinical studies. The latest treatment options have significantly increased the survival of up to three years in the case of advanced disease. The fact that colorectal cancer is developed from a polypoid precursor, as well as the symptoms of the disease that occur at an advanced stage, underlines how screening programs can help early detection and decrease mortality as well as morbidity from CRC.

A novel gastroprotective effect of zeaxanthin against stress-induced gastritis in male rats targeting the expression of HIF-1α, TFF-1 and MMP-9 through PI3K/Akt/JNK signaling pathway

Stress-induced gastritis is a common problem in the intensive care unit. Zeaxanthin (ZE), a non-provitamin A carotenoid has been known to exert antioxidant and anti-inflammatory effects. In this study, we examined the effect of ZE on water avoidance stress (WAS)-induced gastritis in rats. 24 Sprague' Dawley male rats were divided into four groups; control, ZE, WAS and WAS+ZE. In the stressed rats, treatment with ZE effectively downregulated the gastric levels of total oxidant status (TOS), myeloperoxidase (MPO) and malondialdehyde (MDA), with significant upregulation of the antioxidant enzymes' activities and gastric levels of prostagladin-E2 (PGE2) as compared to the untreated stressed one. As noticed in the present study, ZE significantly decrease the gastric levels of interleukin-1 β (IL-1β) and IL-6 as well as suppression of nuclear transcription factor kappa-B (NF-κB) immunohistochemical expression together with upregulation of trefoil factor-1 (TFF-1) gene expression. Moreover, in the untreated WAS-induced gastritis group, gastrin and corticosterone levels were significantly increased together with upregulation of the gene expression of hypoxia inducible factor-1α (HIF-1α), matrix metalloproteinase-9 (MMP-9), PI3K, Akt and JNK in the gastric tissues, which significantly improved by ZE administration. These all positive effects of ZE reflected on reduction of microscopic gastric mucosal damage and inflammatory cell infiltration with improvement of ulcer score. Our results discover that ZE has a new gastroprotective effect against stress-induced gastritis in rats, primarily through its antioxidative and anti-inflammatory effects, which are expressed in the regulation of the MMP-9 and HIF-1α signaling pathways.

Influence of organic solvents in the extraction and purification of torularhodin from Sporobolomyces ruberrimus

OBJECTIVE

This work aimed at evaluating the influence of organic solvents and stationary phases in the extraction with glass beads and chromatographic purification of carotenoids, especially torularhodin, from Sporobolomyces ruberrimus.

RESULTS

The combinations of acetone:hexane (1:1 v/v) and acetone:ethyl ether (1:1 v/v) yielded 171.74 and 172.19 μg of total carotenoids.g of cells^-1, respectively. The first blend resulted in the highest percent of cell lysis of 57.4%. Among different proportions of acetone:hexane, the 9:1 v/v mixture showed a significant difference (p < 0.05), resulting in a recovery of total carotenoids of 221.88 μg.g of cells^-1. The purification of carotenoids was made by preparative chromatography and the yield of the silica-containing stationary phase was higher (24 μg torularhodin.g cells^-1). The analyses of the purified fractions in thin layer chromatography and high performance liquid chromatography indicated that the purification of carotenoids, especially of torularhodin, was successfully performed.

CONCLUSIONS

The combination of polar (acetone) and non-polar solvents (hexane) and the use of silica as stationary phase was efficient to recover and purify torularhodin from the intracellular pigments of Sporobolomyces ruberrimus.

Marine Cyanobacteria and Microalgae Metabolites-A Rich Source of Potential Anticancer Drugs

Cancer is at present one of the utmost deadly diseases worldwide. Past efforts in cancer research have focused on natural medicinal products. Over the past decades, a great deal of initiatives was invested towards isolating and identifying new marine metabolites via pharmaceutical companies, and research institutions in general. Secondary marine metabolites are looked at as a favorable source of potentially new pharmaceutically active compounds, having a vast structural diversity and diverse biological activities; therefore, this is an astonishing source of potentially new anticancer therapy. This review contains an extensive critical discussion on the potential of marine microbial compounds and marine microalgae metabolites as anticancer drugs, highlighting their chemical structure and exploring the underlying mechanisms of action. Current limitation, challenges, and future research pathways were also presented.

Chemoprotective effect of carotenoids from Lycium barbarum L. on SH-SY5Y neuroblastoma cells treated with beauvericin

Goji berry has recently been introduced in Mediterranean diet and its consumption is increasing. This study aims to determine cytoprotection of lutein (LUT), zeaxanthin (ZEAX) and goji berry extract (GBE) rich in carotenoids against Beauvericin (BEA)-induced cytotoxicity on SH-SY5Y neuroblastoma cells. Both carotenoids and GBE showed cytoprotective effects. Cytoprotection was evaluated by simultaneous combination of the two xanthophylls LUT and ZEAX with BEA, as well as using pre-treatment assays. The highest protective effect occurred in 16%, 24% and 12% respectively for LUT, ZEAX and LUT + ZEAX incubating simultaneously with BEA, while by pre-treatment assay LUT showed a cytoprotection effect over 30% and ZEAX alone or LUT + ZEAX promoted only a slight cytoprotection (<10%). Pre-treatment assays with GBE, showed a cytoprotection, between 3 and 20%, for BEA concentrations ranging from 0.1 to 6.25 μM, whereas no protective effect was observed when the cells were simultaneously incubated with GBE and BEA. Finally, by means of CI-isobologram method, the interaction between LUT, ZEAX and BEA were evaluated, and the results showed an synergism effect for almost all combinations tested. The data presented shows a option of using goji berries to potentially mitigate the toxicity of beauvericin eventually present in foods.

Improved functional and nutritional properties of tomato fruit during cold storage

The use of synthetic antioxidants has been associated with serious concerns for human and environmental health. During ripening stages, tomato fruit is exposed to different abiotic stresses which not only influence its nutritional, mechanical, and functional properties at harvest, but also affect the quality and shelf life of the fruit during storage. This study investigated the pattern of changes in dietary antioxidants during various ripening stages of tomato fruit (cv. Red Rose) and their impact on storage behavior of the fruit during cold storage. Tomato fruits were harvested at mature green, breaker, turning, pink, light-red and red stages of maturity. Then, they were analysed for flesh firmness, soluble solids content, titratable acidity, total sugars, pH, dry matter content, lipophilic (lycopene, β-carotene, and total carotenoids), and hydrophilic (ascorbic acid, phenolic and flavonoids) antioxidants. Additional fruits were harvested at each maturity stage and divided into three equal lots, then were subjected to low-temperature (10 ± 1 °C) storage with 80 ± 5% RH, for 7, 14, and 21 days. Flesh firmness, and the levels of dietary antioxidants were analysed following the subsequent storage periods. The results revealed that the peak of hydrophilic antioxidants such as ascorbic acid, phenolic compounds, and flavonoids was between the ‘pink’ and the ‘light-red’ stages of fruit maturity. Whereas tomatoes harvested at the ‘red’ stage of maturity had the highest levels of lycopene and β-carotene. Both the stage of fruit maturity at harvest and duration of cold storage influenced flesh firmness, organoleptic and functional properties of ‘Red Rose’ tomato fruit. In conclusion, the results of the current investigation have practical implications in formulating foods with improved functional properties at processing industries.

Ultrasonic-assisted extraction and high-speed counter-current chromatography purification of zeaxanthin dipalmitate from the fruits of Lycium barbarum L

Zeaxanthin dipalmitate (ZDP) is a major non-saponified carotenoid in fully ripe fruits of Lycium barbarum L. In the present study, response surface methodology was used to optimize the ultrasonic-assisted extraction (UAE) conditions of carotenoids from the fruits of L. barbarum, and the optimal extraction conditions were determined as follows: ultrasonic power of 360 W, ultrasonic time of 40 min and the ratio of extraction solvent to sample of 30 mL/g. An actual value of ZDP content of 5.40 mg/g and short extraction time indicated the efficiency of UAE. Furthermore, a promising high-speed counter-current chromatography (HSCCC) method was established for the purification of ZDP from the fruits of L. barbarum. With a developed two-phase solvent system composed of n-hexane/dichloromethane/acetonitrile (10/3/7, v/v/v), ZDP with a purity of higher than 95% was successfully isolated from the crude extract. This is the first report on the purification of ZDP by using HSCCC.

The non-homogenous distribution and aggregation of carotenoids in the stratum corneum correlates with the organization of intercellular lipids in vivo

The human stratum corneum (SC) contains an abundant amount of carotenoid antioxidants, quenching free radicals and thereby protecting the skin. For the precise measurements of the depth-dependent carotenoid concentration, confocal Raman microscopy is a suitable method. The quantitative concentration can be determined by the carotenoid-related peak intensity of a Gaussian function approached at ≈1524 cm^-1 using non-linear regression. Results show that the carotenoid concentration is higher at the superficial layers of the SC then decreases to a minimum at 20% SC depth and increases again towards the bottom of the SC. In the present work, two carotenoid penetration pathways into the SC are postulated. The first pathway is from the stratum granulosum to the bottom of the SC, while in the second pathway, the carotenoids are delivered to the skin surface by sweat and/or sebum secretion and penetrate from outside. The carotenoids are aggregated at the superficial layers, which are shown by high correlation between the aggregation states of carotenoids and the lateral organization of lipids. At the 30%-40% SC depths, the ordered and dense lipid molecules intensify the lipid-carotenoid interactions and weaken the carotenoid-carotenoid interaction and thus exhibit the disaggregation of carotenoids. At 90%-100% SC depths, the carotenoid-lipid interaction is weakened and the carotenoids have a tendency to be aggregated. Thus, the molecular structural correlation of carotenoid and SC lipid might be reserved in the intercellular space of the SC and also serves as the skeleton of the intercellular lipids.

Microemulsion as nanoreactor for lutein extraction: Optimization for ultrasound pretreatment

In the present study, the capability of microemulsion technique, as a novel technique for synchronous extraction and solubilization of lipophilic compounds, on lutein extraction from marigold petals was investigated. Under the optimized sonication (amplitude 100%, 120 s, 25°C), the extraction efficiency increased (85%) using SDS:ethanol (1:2)-based ME. Moreover, sonication led to smaller droplets (12-163 nm) with favorable thermodynamic stability. In addition, the developed MEs showed higher thermal and especially UV stability in comparison to organic solvent extracts which were fainted with first-order kinetics. It was also found that co-surfactant could be eliminated from formulation on the expense of the optimized sonication, was valuable output form industrial point of view. These findings revealed the high potential of ultrasound technique on the extraction and solubilization of lutein by ME technique which can be directly utilized in lutein-enriched functional foods and beverages. PRACTICAL APPLICATIONS: From applicability point of view, the solvent extracted compounds cannot be easily dissolved in food or pharmaceutical systems that are mostly hydrophilic. Therefore, microemulsions (MEs), as green and environmentally friendly food-grade systems, due to their potential capability for simultaneous extraction and solubilization of carotenoids are of great interest. Therefore, the present study confirmed the practical ability of MEs in lutein extraction and protection. All in all, the developed lutein MEs with high lutein extraction capacity and superior lutein chemical stability against thermal treatment and especially UV radiation is an original finding which allows design of new functional foods and could be potentially useful for enriching foods, pharmaceuticals, nutraceuticals, and supplement formulation.

Nano based lutein extraction from marigold petals: optimization using different surfactants and co-surfactants

Nanotechnology has high potential in processing of industrial crops and by-products in order to extract valuable biological active compounds. The present study endeavored to take advantage of nanotech approach (i.e microemulsion, ME), as a novel green technique, for lutein extraction from marigold (Tagetes erecta) as an industrial crop. The pseudo-ternary phase diagrams confirmed the effect of surfactant type on the formation of mono-phasic lutein MEs. The combination of sucrose monopalmitate:1-poropanol (1:5) showed the highest efficiency in the presence of marigold petal powder (MPP, 18%) and water (42%). In addition, the efficiency of primitive MEs (without co-surfactants) was outstandingly increased as MPP was moistened by co-surfactants. Furthermore, different MEs resulted in various droplet size (14–250nm), PDI (0.05–0.32) and zeta potential (−1.96 to −38.50 mV). These findings revealed the outstanding importance of the surfactants and co-surfactants and their ratio on the extraction capability of MEs. These findings also proved the capability of microemulsion technique (MET) as a potential alternative to conventional solvent with possible applicability for extraction of lutein and other industrial plant based bio-compounds.

Zeaxanthin exerts protective effects on acetic acid-induced colitis in rats via modulation of pro-inflammatory cytokines and oxidative stress

Ulcerative colitis is a common intestinal inflammatory disease characterized by upregulation of pro-inflammatory cytokines and oxidative stress. Zeaxanthin is a nutritional carotenoid that belongs to the xanthophyll family of pigments. It exerts potent anti-inflammatory and antioxidative effects. The present study aimed to evaluate the effect of zeaxanthin on acetic acid-induced ulcerative colitis in rats. Rats were randomly categorized into five groups: control, zeaxanthin, acetic acid, acetic acid + zeaxanthin, and acetic acid + prednisolone groups. Zeaxanthin (50 mg/kg/day) or prednisolone (5 mg/kg/day) was orally administered for 14 days before induction of ulcerative colitis. On the 15th day, colitis was induced by transrectal administration of 3% acetic acid. The rats were sacrificed 24 h after rectal instillation and their colon tissues were examined. Pretreatment with zeaxanthin significantly reduced disease activity index, wet colon weight, ulcer area, macroscopic scores, and histological changes. Zeaxanthin also effectively downregulated the levels of myeloperoxidase and malondialdehyde, upregulated the enzymatic activity of superoxide dismutase and catalase, and raised glutathione levels. With regard to anti-inflammatory mechanisms, zeaxanthin suppressed tumor necrosis factor-alpha, interferon-gamma, interleukin-6, interleukin-1 beta, and nuclear transcription factor kappa B levels, and inhibited nitric oxide synthase and cyclooxygenase-2 protein expression. Our results indicate that oral administration of zeaxanthin ameliorates acetic acid-induced colitis in rats via antioxidative effects and modulation of pro-inflammatory cytokine and mediator activity. Therefore, zeaxanthin may be an effective therapeutic candidate for the treatment of ulcerative colitis.

The Effect of Lutein on Eye and Extra-Eye Health

Lutein is a carotenoid with reported anti-inflammatory properties. A large body of evidence shows that lutein has several beneficial effects, especially on eye health. In particular, lutein is known to improve or even prevent age-related macular disease which is the leading cause of blindness and vision impairment. Furthermore, many studies have reported that lutein may also have positive effects in different clinical conditions, thus ameliorating cognitive function, decreasing the risk of cancer, and improving measures of cardiovascular health. At present, the available data have been obtained from both observational studies investigating lutein intake with food, and a few intervention trials assessing the efficacy of lutein supplementation. In general, sustained lutein consumption, either through diet or supplementation, may contribute to reducing the burden of several chronic diseases. However, there are also conflicting data concerning lutein efficacy in inducing favorable effects on human health and there are no univocal data concerning the most appropriate dosage for daily lutein supplementation. Therefore, based on the most recent findings, this review will focus on lutein properties, dietary sources, usual intake, efficacy in human health, and toxicity.

Imaging of human cells exposed to an antifungal antibiotic amphotericin B reveals the mechanisms associated with the drug toxicity and cell defence

Amphotericin B is an antibiotic used in pharmacotherapy of life-threatening mycotic infections. Unfortunately, the applicability of this antibiotic is associated with highly toxic side effects. In order to understand molecular mechanisms underlying toxicity of amphotericin B to patients, two cell lines, human normal colon epithelial cells (CCD 841 CoTr) and human colon adenocarcinoma cells (HT-29) were cultured in the presence of the drug and imaged with the application of fluorescence lifetime imaging microscopy and Raman scattering microscopy. The results of the cell viability assays confirm high toxicity of amphotericin B towards human cells. The images recorded demonstrate effective binding of amphotericin B to biomembranes. Analysis of the images reveals the operation of a defence mechanism based upon the elimination of molecules of the drug from living cells via formation of small amphotericin B-containing lipid vesicles. The fact that exosomes formed are devoid of cholesterol, as concluded on the basis of the results of Raman analysis, suggests that sequestration of sterols from the lipid phase of biomembranes is not a sole mechanism responsible for the toxic side effects of amphotericin B. Alternatively, the results imply that molecules of the drug present directly within the hydrophobic membrane core disturb the lipid membrane structure and affect their biological functions.

Chemopreventive effects of some popular phytochemicals on human colon cancer: a review

The present review summarizes (1) the epidemiology and etiology of colon cancer, (2) generalized cancer chemoprotective mechanisms, and (3) the chemopreventive properties of some popular phytochemicals as well as some phytochemicals developed by our research group recently.