Modulatory effects of an algal extract containing astaxanthin on UVA-irradiated cells in culture

Discovering the link between nutrition and skin aging

Skin has been reported to reflect the general inner-health status and aging. Nutrition and its reflection on skin has always been an interesting topic for scientists and physicians throughout the centuries worldwide. Vitamins, carotenoids, tocopherols, flavonoids and a variety of plant extracts have been reported to possess potent anti-oxidant properties and have been widely used in the skin care industry either as topically applied agents or oral supplements in an attempt to prolong youthful skin appearance. This review will provide an overview of the current literature "linking" nutrition with skin aging.

Applications of marine nutraceuticals in dairy products

The concept of nutraceutical has been derived by coining the terms "nutrition" and "pharmaceutical". In this context, active substances with pharmaceutical properties are delivered to the humans through food-based approaches to prevent or treat certain disease conditions. Since the natural sources are recognized as safe for human consumption, the active substances produced in the diverse group of marine organisms have a wide role in the nutraceutical industry. These marine-derived active ingredients include certain polysaccharides, polyphenols, bioactive peptides, polyunsaturated fatty acids, and carotenoids which are known to have anticancer, anti-inflammatory, antioxidant, antiobese, hypocholesteroleic, antimicrobial, prebiotic, and probiotic activity enabling them to be applied as nutraceuticals. As the dairy products are widely accepted by the consumers, the delivering of nutraceuticals through dairy products have received a greater attention of the dairy industry. Since the incorporation of marine-derived active ingredients into the dairy products have caused minimal changes in the physico-chemical properties of the final product, marine-derived substances have been widely applied and have the potential to be applied as nutraceuticals in the dairy industry.

Protective effect of triphlorethol-A against ultraviolet B-mediated damage of human keratinocytes

Ultraviolet B (UVB) radiation on human skin induces pathophysiological processes such as oxidative stress and inflammation. In previous reports, the antioxidant effects of triphlorethol-A were shown to protect cells against hydrogen peroxide-induced cell damage and gamma ray-induced oxidative stress. In this study, the role of triphlorethol-A in protecting human keratinocytes (HaCaT) against UVB-induced cell damage was investigated. Triphlorethol-A-treated cells were irradiated with UVB (150 mJ/cm(2)). Triphlorethol-A decreased UVB-induced intracellular ROS and restored the activities of antioxidant enzymes decreased by UVB radiation. Triphlorethol-A decreased UVB damage to cellular components, such as lipid membrane and DNA, restored cell viability and reduced UVB-induced apoptosis by inhibiting the mitochondria-mediated caspase pathway. Triphlorethol-A also reduced the UVB-induced loss of ΔΨ(m) and the active forms of caspase 9 and caspase 3. The anti-apoptotic effect of triphlorethol-A was found to involve the inhibition of c-Jun NH(2)-terminal kinase, which was induced by UVB exposure. And triphlorethol-A showed an absorptive capacity at range of UVB. These results suggest that triphlorethol-A protects human keratinocytes against UVB by enhancing the activities of the antioxidant system, inhibiting cellular damage and absorbing the UVB.

Microalgae for "Healthy" Foods-Possibilities and Challenges

  Microalgae have the potential to become a novel source of bioactive molecules, especially for those who might wish to enhance the nutritional and functional quality of foods. Spirulina, one of the most popular microalgae, has been described by the World Health Organization as one of the greatest superfoods on earth serving as an example of the potential of microalgae. This review provides background on current and future uses of microalgae in the human diet, lists the most common species of microalgae used to this end, and describes some production methods used in research and industrial production and recovery. The review also discusses some of the difficulties so far encountered such as low productivities and recovery rates, as well as challenges in the production of compounds of interest. Many scientists and engineers in research centers around the globe are currently dedicated to solve these problems as the various capabilities of microalgae have caught the attention of the energy, environmental, and agricultural industries, we propose that the food industry should as well evaluate the potential of microalgae as a novel source of "health promoting" compounds.

The in vitro effects of Xancor, a synthetic astaxanthine derivative, on hemostatic biomarkers in aspirin-naïve and aspirin-treated subjects with multiple risk factors for vascular disease

Astaxanthine is a polar carotenoid metabolite derived from a proprietary prodrug, Xancor, which aligns parallel with the membrane phospholipids exhibiting potent antioxidant, anti-inflammatory, and cell protective properties, although the precise mechanism of action is unknown. This prodrug is currently under development for hepatic, neurologic, and vascular disease indications. Considering established links between heart disease and stroke with platelets, coagulation cascade, and fibrinolysis, the aim of the study was to assess the effect of asthaxantine on human biomarkers of hemostasis. The rationale was to test a hypothesis that the drug may diminish activation of hemostasis, making it a potentially attractive addition to treat patients with vascular disease. In vitro effects of whole blood preincubation with escalating concentrations of asthaxantine (0.3 microM, 1 microM, 3 microM, 10 microM, 30 microM, and 100 microM) were assessed from 12 aspirin-naïve and eight aspirin-treated volunteers with multiple risk factors for vascular disease. A total of 25 biomarkers were measured, of which 12 were related to platelet function, 10 to coagulation, and three to fibrinolysis. Platelet aggregation induced by ADP, collagen, and arachidonic acid and expression of CD31, CD41, GP IIb/IIIa, CD51/61, P-selectin, CD63, CD107a, CD151+CD14, and CD154 were not affected. Coagulation indices such as aPTT, prothrombin time, thrombin time, fibrinogen, antithrombin III (antigen and activity), Protein C, Protein S (free and activity), and von Willebrand factor remained unchanged after incubation with astaxanthine. Fibrinolytic activity biomarkers such as plasminogen, D-dimer, and FDP were also not affected after in vitro pretreatment of blood samples with astaxanthine. In the projected subclinical (less than 1 microM), therapeutic (3 microM to 30 microM), and supratherapeutic concentration (100 microM), astaxanthine in vitro does not affect platelet, coagulation, or fibrinolytic indices in either aspirin-naïve or aspirin-treated subjects. These results are important for the assessment of the safety profile, but remain to be confirmed preclinically, in vivo, and ultimately in the clinic.

Anti-photoaging and photoprotective compounds derived from marine organisms

Marine organisms form a prominent component of the oceanic population, which significantly contribute in the production of cosmeceutical and pharmaceutical molecules with biologically efficient moieties. In addition to the molecules of various biological activities like anti-bacterial, anti-cancerous, anti-inflammatory and anti-oxidative etc., these organisms also produce potential photoprotective or anti-photoaging agents, which are attracting present day researchers. Continuous exposure to UV irradiation (both UV-A and UV-B) leads to the skin cancer and other photoaging complications, which are typically mediated by the reactive oxygen species (ROS), generated in the oxidative pathways. Many of the anti-oxidative and anti-photoaging compounds have been identified previously, which work efficiently against photodamage of the skin. Recently, marine originated photoprotective or anti-photoaging behavior was observed in the methanol extracts of Corallina pilulifera (CPM). These extracts were found to exert potent antioxidant activity and protective effect on UV-A-induced oxidative stress in human dermal fibroblast (HDF) cells by protecting DNA and also by inhibiting matrix metalloproteinases (MMPs), a key component in photoaging of the skin due to exposure to UV-A. The present review depicts various other photoprotective compounds from algae and other marine sources for further elaborative research and their probable use in cosmeceutical and pharmaceutical industries.

Astaxanthin decreased oxidative stress and inflammation and enhanced immune response in humans

Background

Astaxanthin modulates immune response, inhibits cancer cell growth, reduces bacterial load and gastric inflammation, and protects against UVA-induced oxidative stress in in vitro and rodent models. Similar clinical studies in humans are unavailable. Our objective is to study the action of dietary astaxanthin in modulating immune response, oxidative status and inflammation in young healthy adult female human subjects.

Methods

Participants (averaged 21.5 yr) received 0, 2, or 8 mg astaxanthin (n = 14/diet) daily for 8 wk in a randomized double-blind, placebo-controlled study. Immune response was assessed on wk 0, 4 and 8, and tuberculin test performed on wk 8.

Results

Plasma astaxanthin increased (P < 0.01) dose-dependently after 4 or 8 wk of supplementation. Astaxanthin decreased a DNA damage biomarker after 4 wk but did not affect lipid peroxidation. Plasma C-reactive protein concentration was lower (P < 0.05) on wk 8 in subjects given 2 mg astaxanthin. Dietary astaxanthin stimulated mitogen-induced lymphoproliferation, increased natural killer cell cytotoxic activity, and increased total T and B cell subpopulations, but did not influence populations of T_helper, T_cytotoxic or natural killer cells. A higher percentage of leukocytes expressed the LFA-1 marker in subjects given 2 mg astaxanthin on wk 8. Subjects fed 2 mg astaxanthin had a higher tuberculin response than unsupplemented subjects. There was no difference in TNF and IL-2 concentrations, but plasma IFN-γ and IL-6 increased on wk 8 in subjects given 8 mg astaxanthin.

Conclusion

Therefore, dietary astaxanthin decreases a DNA damage biomarker and acute phase protein, and enhances immune response in young healthy females.

Cytoprotective role of astaxanthin against glycated protein/iron chelate-induced toxicity in human umbilical vein endothelial cells

Astaxanthin (ASX), a red carotenoid pigment with no pro-vitamin A activity, is a biological antioxidant that occurs naturally in a wide variety of plants, algae and seafoods. This study investigated whether ASX could inhibit glycated protein/iron chelate-induced toxicity in human umbilical-vein endothelial cells (HUVEC) by interfering with ROS generation in these cells. Glycated fetal bovine serum (GFBS) was prepared by incubating fetal bovine serum (FBS) with high-concentration glucose. Stimulation of cultured HUVECs with 50 mm 1 mL of GFBS significantly enhanced lipid peroxidation and decreased antioxidant enzyme activities and levels of phase II enzymes. However, preincubation of the cultures with ASX resulted in a marked decrease in the level of lipid peroxide (LPO) and an increase in the levels of antioxidant enzymes in an ASX concentration-dependent manner. These results demonstrate that ASX could inhibit LPO formation and enhance the antioxidant enzyme status in GFBS/iron chelate-exposed endothelial cells by suppressing ROS generation, thereby limiting the effects of the AGE-RAGE interaction. The results indicate that ASX could have a beneficial role against glycated protein/iron chelate-induced toxicity by preventing lipid and protein oxidation and increasing the activity of antioxidant enzymes.

Astaxanthin reduces ischemic brain injury in adult rats

Astaxanthin (ATX) is a dietary carotenoid of crustaceans and fish that contributes to their coloration. Dietary ATX is important for development and survival of salmonids and crustaceans and has been shown to reduce cardiac ischemic injury in rodents. The purpose of this study was to examine whether ATX can protect against ischemic injury in the mammalian brain. Adult rats were injected intracerebroventricularly with ATX or vehicle prior to a 60-min middle cerebral artery occlusion (MCAo). ATX was present in the infarction area at 70-75 min after onset of MCAo. Treatment with ATX, compared to vehicle, increased locomotor activity in stroke rats and reduced cerebral infarction at 2 d after MCAo. To evaluate the protective mechanisms of ATX against stroke, brain tissues were assayed for free radical damage, apoptosis, and excitoxicity. ATX antagonized ischemia-mediated loss of aconitase activity and reduced glutamate release, lipid peroxidation, translocation of cytochrome c, and TUNEL labeling in the ischemic cortex. ATX did not alter physiological parameters, such as body temperature, brain temperature, cerebral blood flow, blood gases, blood pressure, and pH. Collectively, our data suggest that ATX can reduce ischemia-related injury in brain tissue through the inhibition of oxidative stress, reduction of glutamate release, and antiapoptosis. ATX may be clinically useful for patients vulnerable or prone to ischemic events.

Antiinflammatory triterpenoids and steroids from Ganoderma lucidum and G. tsugae

The antiinflammatory properties of triterpenoids and steroids from both Ganoderma lucidum and Ganoderma tsugae were studied. Twelve compounds, including ergosta-7,22-dien-3beta-ol (1), ergosta-7,22-dien-3beta-yl palmitate (2), ergosta-7,22-dien-3-one (3), ergosta-7,22-dien-2beta,3alpha,9alpha-triol (4), 5alpha,8alpha-epidioxyergosta-6,22-dien-3beta-ol (5), ganoderal A (6), ganoderal B (7), ganoderic aldehyde A (8), tsugaric acid A (9), 3-oxo-5alpha-lanosta-8,24-dien-21-oic acid (10), 3alpha-acetoxy-5alpha-lanosta-8,24-dien-21-oic acid ester beta-d-glucoside (11), and tsugaric acid B (12), were assessed in vitro by determining their inhibitory effects on the chemical mediators released from mast cells, neutrophils, and macrophages. Compound 10 showed a significant inhibitory effect on the release of beta-glucuronidase from rat neutrophils stimulated with formyl-Met-Leu-Phe (fMLP)/cytochalasin B (CB) whereas compound 9 significantly inhibited superoxide anion formation in fMLP/CB-stimulated rat neutrophils. Compound 10 also exhibited a potent inhibitory effect on NO production in lipopolysaccharide (LPS)/interferon-gamma (IFN-gamma)-stimulated N9 microglial cells. Moreover, compound 9 was also able to protect human keratinocytes against damage induced by ultraviolet B (UV B) light, which indicated 9 could protect keratinocytes from photodamage.

(-)-Epicatechin-3-gallate, a green tea polyphenol is a potent agent against UVB-induced damage in HaCaT keratinocytes

(-)-Epicatechin-3-gallate (ECG) is a polyphenolic compound similar to (-)-epigallocatechin-3-gallate (EGCG) which is abundant in green tea. Numerous workers have proposed that EGCG protects epidermal cells against UVB-induced damage. However, little has been known about whether ECG protects keratinocytes against UVB-induced damage. We decided to investigate the protective effects and underlying mechanisms of ECG on UVB-induced damage. Cell viability was determined by the MTT assay. Activation of ERK1/2, p38 and JNK was analyzed by Western blotting. Intracellular H2O2 production and DNA content was analyzed by flow cytometry. Lipid peroxidation was assayed by colorimetry. In our study, we found that ECG dose-dependently attenuated UVB-induced keratinocyte death. Moreover, ECG markedly inhibited UVB-induced cell membrane lipid peroxidation and H2O2 generation in keratinocytes, suggesting that ECG can act as a free radical scavenger when keratinocytes were photodamaged. In parallel, H2O2-induced the activation of ERK1/2, p38 and JNK in keratinocytes could be inhibited by ECG. UVB-induced pre-G1 arrest leading to apoptotic changes of keratinocytes were blocked by ECG. Taken together, we provide here evidence that ECG protects keratinocytes from UVB-induced photodamage and H2O2-induced oxidative stress, possibly through inhibition of the activation of ERK1/2, p38 and JNK and/or scavenging of free radicals.

C-26 and C-30 apocarotenoids from seeds of Ditaxis heterantha with antioxidant activity and protection against DNA oxidative damage

The hexane extracts of seeds of Ditaxis heterantha afforded two new apocarotenoids whose structures corresponded to methyl 3-oxo-12'-apo-epsilon-caroten-12'-oate (1) (heteranthin) and methyl 3beta,6beta-epoxy-5beta-hydroxy-4,5-dihydro-8'-apo-epsilon-caroten-8'-oate (2) (ditaxin). Both compounds were evaluated for antioxidant activity and protection against DNA oxidative damage by using DPPH* free radical scavenging and Comet assays, respectively.

Ultraviolet (UV) A- and UVB-induced redox alterations and activation of nuclear factor-κB in human melanocytes-protective effects ofα-tocopherol

BACKGROUND

Despite compelling evidence that ultraviolet (UV) irradiation causes melanoma the knowledge concerning reaction pathways and signalling transduction in melanocytes is still limited.

OBJECTIVES

To evaluate the protective capacity of alpha-tocopherol and beta-carotene during UVA and UVB irradiation of human melanocytes in vitro.

METHODS

Primary cultures of normal human melanocytes were irradiated by different wavelengths within the UV spectrum (UVA 6 J cm(-2), UVB 60 mJ cm(-2)). Redox alterations and apoptosis were studied and the protective potential of alpha-tocopherol and beta-carotene was evaluated.

RESULTS

UVA and UVB irradiation decreased the intracellular concentration of reduced glutathione and activated the transcription factor nuclear factor (NF)-kappaB, detected as the increased level of the p65 subunit and translocation to the nucleus. This coincided with a rise in the level of gamma-glutamyl-cysteine-synthetase, the rate-limiting enzyme of the glutathione synthesis. UVA and UVB caused apoptotic cell death as detected by nuclear fragmentation and caspase activation 24 h postirradiation. Pretreatment with alpha-tocopherol prevented UVA- and UVB-induced glutathione loss, NF-kappaB translocation and diminished apoptosis, but beta-carotene did not show a similar protective capacity. Further, exposure to alpha-tocopherol by itself reduced cell proliferation rate.

CONCLUSIONS

UVA and UVB irradiation affected the intracellular redox state and increased the frequency of apoptosis in human melanocytes in vitro. alpha-Tocopherol might be a useful substance in protecting melanocytes from UV-induced damage.

Astaxanthin, a carotenoid with potential in human health and nutrition

Astaxanthin (1), a red-orange carotenoid pigment, is a powerful biological antioxidant that occurs naturally in a wide variety of living organisms. The potent antioxidant property of 1 has been implicated in its various biological activities demonstrated in both experimental animals and clinical studies. Compound 1 has considerable potential and promising applications in human health and nutrition. In this review, the recent scientific literature (from 2002 to 2005) is covered on the most significant activities of 1, including its antioxidative and anti-inflammatory properties, its effects on cancer, diabetes, the immune system, and ocular health, and other related aspects. We also discuss the green microalga Haematococcus pluvialis, the richest source of natural 1, and its utilization in the promotion of human health, including the antihypertensive and neuroprotective potentials of 1, emphasizing our experimental data on the effects of dietary astaxanthin on blood pressure, stroke, and vascular dementia in animal models, is described.

Astaxanthin: A Review of its Chemistry and Applications

Astaxanthin is a carotenoid widely used in salmonid and crustacean aquaculture to provide the pink color characteristic of that species. This application has been well documented for over two decades and is currently the major market driver for the pigment. Additionally, astaxanthin also plays a key role as an intermediary in reproductive processes. Synthetic astaxanthin dominates the world market but recent interest in natural sources of the pigment has increased substantially. Common sources of natural astaxanthin are the green algae Haematococcus pluvialis, the red yeast, Phaffia rhodozyma, as well as crustacean byproducts. Astaxanthin possesses an unusual antioxidant activity which has caused a surge in the nutraceutical market for the encapsulated product. Also, health benefits such as cardiovascular disease prevention, immune system boosting, bioactivity against Helycobacter pylori, and cataract prevention, have been associated with astaxanthin consumption. Research on the health benefits of astaxanthin is very recent and has mostly been performed in vitro or at the pre-clinical level with humans. This paper reviews the current available evidence regarding astaxanthin chemistry and its potential beneficial effects in humans.

Protective effects of (-)-epicatechin-3-gallate on UVA-induced damage in HaCaT keratinocytes

(-)-Epigallocatechin-3-gallate (EGCG), a constituent of green tea, has been extensively studied and shown to be a powerful antioxidant protecting skin cells against photodamage. In this study, however, we demonstrated that another gallated catechin, (-)-epicatechin-3-gallate (ECG), was also able to protect human keratinocytes against damage induced by ultraviolet A (UVA) light. We found that ECG dose-dependently inhibited UVA-induced keratinocyte death as determined by cell viability assay. Moreover, ECG had similar potency to EGCG in inhibiting UVA-induced cell death. Therefore, the mechanism of action of ECG was further investigated. As assayed by flow cytometry, UVA-induced hydrogen peroxide (H2O2) production in keratinocytes was inhibited by ECG in a concentration-dependent manner, suggesting that ECG can act as a free radical scavenger while keratinocytes were photodamaged. The scavenging effect of ECG was confirmed by the fact that ECG treatment attenuated cell damage induced by H2O2 and hypoxanthine-xanthine oxidase. In a parallel experiment, UVA-induced activation of extracellular signal-regulated kinase in keratinocytes was blocked by ECG. We provided here the first evidence that ECG is a potent protectant that protects keratinocytes from photodamage. Because ECG is abundant in green tea, we believe that this compound is beneficial for skin care.

The Combined Effects of Extracts Containing Carotenoids and Vitamins E and C on Growth and Pigmentation of Cultured Human Melanocytes

In the present study, we investigated the effects of tomato extract (TE) containing lycopene and palm fruit extract (PE) rich in carotenoids on the growth and pigmentation of melanocyte cultures of Caucasian origin. The extracts were tested at different concentrations and in combination with vitamins E and C. Melanocytes with basic and increased (tyrosine-induced) pigmentation were treated in short-term and long-term experiments. Prevention of UVA-induced DNA damage was studied by using the comet assay. Melanocytes with stimulated melanin production showed reduced growth. Incubation of the cells with TE/PE (20/4 microg/ml) in combination with 35 microM vitamin E and 100 microM vitamin C (COMB 20/4) reduced this growth inhibition, especially in the long-term cultures. Increased production of melanin pigment was obtained when the cells were treated with 2.5 x and 10 x higher concentrations of the TE/PE and the same concentration of vitamins E and C (COMB 50/10 and 200/40). Reduced DNA damage was found after UVA irradiation in cells preincubated with COMB 50/10. The results indicate that the presence of carotenoids from TE and PE in combination with vitamins E and C may influence growth and pigmentation in melanocyte monocultures. Depending on the concentration of the carotenoid mixtures, their presence may provide some protection against the melanogenic intermediates and/or exogenous DNA damage.

Use of the comet assay for studying environmental genotoxicity: comparisons between visual and image analyses

In order to evaluate the applicability of different measurement parameters employed in the comet assay for analyzing environmental samples, fish hepatoma (RTH-149) cells were exposed to concentrations of the model genotoxic agent hydrogen peroxide (H(2)O(2); 1, 5, and 10 microM) and to five water samples from sites along the Kishon River, the most polluted river in Israel. DNA damage was scored in parallel by visual and computer-image (Viscomet) analyses using 12 different parameters. Each parameter exhibited a different profile of responses. The four visual parameters were highly sensitive to the lowest (1 microM) H(2)O(2) concentration (1.8-7.0-fold of the control). At 10 microM H(2)O(2) exposure, the visual parameter, percentage severe damage, showed the highest (40.3-fold) response while four other parameters, tail area, tail extent moment (Viscomet), mean actual tail length and cumulative tail length (visual analysis), also had substantially elevated responses (8-11-fold). We found that the DNA damage induced by field samples was similar in magnitude to the damage induced by 1 microM H(2)O(2), with only some of the parameters being highly sensitive to the damage. Only about one-half of the parameters could distinguish four significant levels of genotoxicity among the five sampling sites, while the remaining parameters detected only three levels. It is concluded that the choice of parameters for analyzing genotoxicity in ecotoxicological studies should be made in accordance with the characteristics of each parameter.