Orychophragine D:A new 2-piperazinone fused 5-azacytosine type alkaloid with radioprotective activity from the seeds of Orychophragmus violaceus.

A new alkaloid, Orychophragine D (1), together with three known alkaloids, were isolated from the seeds of Orychophragmus violaceus. Orychophragine D represented the first example of 2-piperazinone fused 5-azacytosine skeleton. Their structures and absolute configurations were determined by spectroscopic analyses and X-ray crystallography. Compared to Ex-RAD, compound 1 exhibited a significant radioprotective activity on cell survival of irradiated HUVEC. In vivo experiments showed that 1 not only remarkably enhanced the survival of irradiated mice in 30 days, but also significantly promoted the recovery of the blood system of irradiated mice. These results suggested that 1 was valuable for further research as promising radioprotectors.

Black tea is more effective than green tea in prevention of radiation-induced oxidative stress in the aorta of rats.

In the work, the effect of black tea on oxidative stress induced in the aorta by irradiation was studied. The efficiency of black and green tea types was compared, and the effect of the main green tea components (-)-epigallocatechin galate (EGCG) and (-)-epigallocatechin (EGC) on the aorta was studied. The activity of ACE in rat aorta segments was determined by measuring the hydrolysis of hippuryl-L-histidyl-L-leucine, and the production of ROS was estimated from the oxidation of dichlorodihydrofluorescein. Black tea prevented the radiation-induced activation of the ACE and suppressed increased ROS production in the aorta of irradiated rats. The IC50 value for the suppression of the irradiation-induced increase in ACE activity is 1 ml of black tea brewed at a rate of 0.17 g/100 ml. Black tea is 12 times more effective than green tea. The administration of both catechin derivatives from green tea to rats leads to an increase in the activity of ACE and the formation of ROS in the aorta. The dose that provided half maximum activation of ACE (EC50) on intraperitoneal (i. p.) injection of galloylated catechins was found to be the same, 0.06-0.07 µg/kg of body weight. Upon intragastric gavage of EGCG, the EC50 value was by one order of magnitude higher, 0.8 µg/kg. Black tea was more effective than green tea in prevention a radiation-induced increase of ACE activity and oxidative stress in the aorta. This difference was explained by a low content of galloylated catechins in black tea.

Photoprotective Potential of the Natural Artocarpin against In Vitro UVB-Induced Apoptosis.

Apoptosis, a well-known pattern of programmed cell death, occurs in multicellular organisms not only for controlling tissue homeostasis but also for getting rid of severely damaged cells in order to protect the redundant growth of abnormal cells undergoing cancerous cells. The epidermis of the human skin, composed largely of keratinocytes (KCs), is renewed continuously. Therefore, KCs apoptosis plays a critical role in the maintenance of epidermis structure and function. However, regulated cell death can be disturbed by environmental factors especially ultraviolet radiation (UV) B, leading to the formation of sunburn cells (KCs undergoing UVB-induced apoptosis) and impairing the skin integrity. In the present study, we firstly reported the potential of the natural artocarpin (NAR) to regulate UVB-induced human KCs apoptosis. The NAR showed antilipid peroxidation with an IC50 value of 18.2 ± 1.6 µg/mL, according to TBARS assay while the IC50 value of trolox, a well-known antioxidant, was 7.3 ± 0.8 µg/mL. For cell-based studies, KCs were pretreated with 3.1 µg/mL of the NAR for 24 hr and then exposed to UVB at 55 mJ/cm2. Our data indicated that the NAR pretreatment reduces UVB-induced oxidative stress by scavenging free radicals and nitric oxide and therefore prevents reactive oxygen species (ROS) and reactive nitrogen species- (RNS-) mediated apoptosis. The NAR pretreatment has been shown also to reduce the UVB-induced cyclobutane pyrimidine dimer (CPD) lesions by absorbing UVB radiation and regulating the cell cycle phase. Additionally, the NAR pretreatment was found to modulate the expression of cleaved caspases-3 and 8 that trigger different signalling cascades leading to apoptosis. Thus, these results provide a basis for the investigation of the photoprotective effect of the NAR isolated from A. altilis heartwood and suggest that it can be potentially used as an agent against UVB-induced skin damages.

Step gradient alcohol precipitation for the purification of low molecular weight fucoidan from Sargassum siliquastrum and its UVB protective effects.

Ultraviolet B (UVB) can induce oxidative damage to outermost layers of skin causing suntans, sunburns, and, in severe cases, blisters leading to photoaging. Low molecular weight (MW) fucoidan is renowned for possessing enhanced antioxidant activities. The present study discloses the use of step gradient ethanol precipitation in refining fucoidan fractions (SSQC1-SSQC4) from Sargassum siliquastrum and evaluation of their UVB-protective effects in human HaCaT keratinocytes. Among the fractions, SSQC4 indicated the best bioactive effects. 1H NMR, FTIR, monosaccharide composition by HPAEC-PAD analysis, MW estimation by agarose gel electrophoresis were used to characterize the fractions. SSQC4 was comprising of fucoidan, with an estimated MW distribution of 8-25 kDa. Exposure of UVB increased intracellular ROS, DNA damage, loss of mitochondrial membrane potential, apoptotic body formation causing cell death through the mitochondria-mediated apoptosis pathway. SSQC4 treatment could dose-dependently attenuate the ROS levels and suppress mitochondria-mediated apoptosis in UVB exposed keratinocytes. SSQC4 treatment enhanced cellular antioxidant defense by increasing Nrf2 mediated HO-1 generation, which was identified as the cause of observed bioactivities. The safety and stability of SSQC4 could be further evaluated to promote its use as a bioactive natural ingredient in UV-protective cosmetics.

UPLC-MS-based serum metabolomics reveals protective effect of Ganoderma lucidum polysaccharide on ionizing radiation injury.

ETHNOPHARMACOLOGICAL RELEVANCE: Ganoderma lucidum Polysaccharide (GLP),traditional Chinese medicine (TCM) active ingredient, has a long history and has good curative effects on radiation injury. However, the mechanism of GLP treating radiation injury has not been clearly elucidated. THE AIM OF THE STUDY: This study was aimed to investigate the preventive effects of GLP on mice with radiation injury and to explore its mechanisms by serum metabolomics. MATERIALS AND METHODS: Thirty mice were randomly divided into three groups,and namely 10 per group. The normal control group and the radiation model with normal saline and GLP group with GLP treatment (96 mg·kg-1) for 14 days. 2 h after 7th day after the intragastric administration, the model group and GLP group were subjected to whole body irradiation by X-rays except the normal control group. The peripheral blood WBC, RBC, HGB, PLT indicators.UPLC-Q-TOF-MS technique was used to analyze the serum of normal group, model group and GLP group, and to explore its potential key biomarkers and corresponding related metabolic pathways. RESULTS: The number of peripheral blood leukocytes (WBC) in the radiation model group was lower than that in the GLP group and the number of platelets (PLT) in the GLP group was significantly higher than that in the model group.Combined with the methods of principal component analysis (PCA), projection to latent structure-discrimination analysis (PLS-DA), three group were clearly distinguished from each other and 18 metabolites were identified as the potential biomarkers in the GLP treated mice. The identified biomarkers indicated that there were perturbations of the taurine and hypotaurine metabolism and glycerophospholipid metabolism. CONCLUSION: GLP can play a role in radiation protection by improving the expression of related potential biomarkers and related metabolic pathways in serum of radiation-induced mice.

Protective effects of Cordyceps extract against UVB­induced damage and prediction of application prospects in the topical administration: An experimental validation and network pharmacology study.

ETHNOPHARMACOLOGICAL RELEVANCE: UVB is a high energy source that causes the major risk factor for sunburn and skin tumor. However, photochemical interactions lead to beneficial effects such as synthesis of vitamin D and corticosteroids. Therefore, a reasonable therapeutic regime is advocated to reduce UVB injuries but makes use of synthesizing sunlight metabolite. Many natural compounds improving plant cells resistant to oxidative stress by the harnessing of solar energy may be also used to protect human cells. Although many nature plants have shown photoprotective effects on skin, the mechanisms underlying of the effects are still ambiguous. AIM OF THE STUDY: This study evaluates the protective effects of cultivated Cordyceps against UVB-induced damage in human keratinocytes and identifies the photoprotective mechanisms using a transcriptomic network approach. MATERIALS AND METHODS: Cordyceps extract compositions were investigated by HPLC analysis. Cell survival, reactive oxygen species (ROS) generation, H2O2 content, aquaporin 3 (AQP3) level and DNA damage were determined upon UVB irradiation in the presence of Cordyceps extract. In addition, next-generation sequencing was used to profile transcriptomic alteration of 20 mJ/cm2 UVB and non-UV. Finally, a network pharmacology method was applied to study Cordyceps extract-related natural compounds and their UVB-induced differentially change targets using the Cytoscape 3.7.1 software. RESULTS: Adenosine and mannitol were the major contents in Cordyceps extract. Cordyceps caused a significant diminished in intracellular UVB-induced oxidative stress, including ROS production and intracellular H2O2 content. Besides, AQP3 which mediated intracellular signal transmission and transported H2O2 into cells was significantly increased in the presence of Cordyceps extract against UVB irradiation. In addition, DNA repair effect of Cordyceps extract after UV irradiation was proven to be effective by comet assay. Moreover, KEGG analysis showed steroid hormone biosynthesis, ovarian steroidogenesis, fat digestion and absorption were enriched in top 3 between 20 mJ/cm2 UVB and non-UV. Gene ontology (Go) analysis showed that steroid metabolic process, sterol metabolic process, and cholesterol metabolic process were enriched in top3 biology process. By using network analysis, 125 potential bioactive ingredients in Cordyceps and 201 targets were identified. Finally, signal pathway analyses suggested that the protective effects of Cordyceps compounds against low dose UVB­induced changes might target PPAR signaling pathway, cholesterol metabolism, and ovarian steroidogenesis. CONCLUSION: Cordyceps extract may be an ideal product for external use of skin which could not only avoid UVB-induced adverse effects, but also could application of metabolite products by UVB such us steroid hormone and vitamin D3.

Prophylactic Effect of Opuntia ficus indica Fruit Peel Extract against Irradiation-Induced Colon Injury in Rats.

Opuntia ficus-indica extract has been used in traditional folk medicine for several purposes and exhibits anti-inflammatory properties. This study was directed to explore the prophylactic effect of O. ficus-indica fruit peel extract against irradiation-induced colitis in rats. GC/MS analysis of the petroleum ether extract led to recognition of 33 compounds in the unsaponifiable fraction and 15 fatty acid methyl esters in the saponifiable part. Thirteen terpenes and sterols were isolated and identified from which ten compounds were not isolated from any part of this species before. Data showed that irradiation induced colon injury as manifested by elevated contents of malondialdehyde, nitric oxide, myeloperoxidase, intercellular adhesion molecule-1, cyclooxygenase-2, tumor necrosis factor alpha, and nuclear factor kappa B, while it reduced superoxide dismutase activity and interleukin 10 content in colonic tissues, which was confirmed by histopathological examination. Pretreatment with O. ficus-indica extract attenuated the alteration in the measured parameters. It could be concluded that O. ficus-indica fruit peel extract can be regarded as a potential agent in limiting colonic complications due to irradiation, possibly by its antioxidant and anti-inflammatory properties.

Photoprotective effects of 2S,3R-6-methoxycarbonylgallocatechin isolated from Anhua dark tea on UVB-induced inflammatory responses in human keratinocytes.

Ultraviolet B (UVB) induces inflammation and causes skin aging. The signs of skin aging, such as wrinkles, discolored spots, loss of skin moisture, and disruption of the skin barrier, are mostly caused by inflammatory signaling among various skin layers. The cells on the outermost surface of the skin are keratinocytes; these cells protect the skin against environmental stress and play an important role in immunomodulation by secreting cytokines in response to environmental stress. In the present study, we found that UVB activates STAT1 to mediate inflammatory signaling, yet STAT1 (S272) and STAT (Y702) shows different responses against UVB exposure. Anhua drak tea is a post-fermented dark tea produced in Anhua and Xinhua country in Hunan province of China. Treatment with 2S,3R-6-methoxycarbonylgallocatechin (MCGE), an epigallocatechin gallate derivative isolated from black tea (Anhua dark tea), effectively suppresses STAT1 activation and inflammatory cytokines, and activates Nrf2 pathway to protect cells from reactive oxygen species production in UVB exposed keratinocyte cells (HaCaT). Interestingly, the effects of MCGE were independent on MAPK signaling pathway. Moreover, MCGE regulates inflammatory cytokines in monocyte-keratinocyte (THP-1, HaCaT) co-culture and macrophage differentiation models. These results suggest that MCGE potentially can be used as a photoprotective agent against UVB-induced inflammatory responses.

ASSESSMENT OF RADIOPROTECTIVE ACTION OF BASIDIOMYCOTIC MELANIN PIGMENTS ON THE HEMATOPOIETIC SYSTEM OF Balb/C MICE UNDER EXPOSURE TO IONIZING RADIATION IN SUBLETHAL DOSE. / OTsINKA RADIOPROTEKTORNOÏ DIÏ MELANINOVYKh PIGMENTIV BAZYDIOMITsETIV NA GEMOPOETYChNU SYSTEMU MYShEY̆ Balb/C PRY OPROMINENNI IONIZUIuChOIu RADIATsIIeIu U SUBLETAL'NIY̆ DOZI.

OBJECTIVE: Assessment of radioprotective action of basidiomycotic melanin pigments on hematopoietic stem and progenitor bone marrow cells of Balb/C mice in case of exposure to ionizing radiation in sublethal dose. MATERIALS AND METHODS: Using original method of cultivation in gel diffusion chambers in vivo of bone marrow cells of Balb/C mice we investigated the colony-forming efficiency of hematopoietic progenitor cells of the ani- mals, which were exposed to ionizing radiation action in sublethal dose, in case of treatment with melanin pig- ments solution of basidiomycotic fungi as radioprotector. RESULTS AND CONCLUSIONS: Investigation of functional activity of bone marrow progenitor cells of Balb/C mice allowed assessing their hematopoiesis state in case of ionizing radiation action, as well as in case of previous treat- ment of the animals with the solution of melanin pigments as radioprotector. It was determined that under the influence of ionizing radiation the colony-forming activity of mice bone marrow has decreased comparing to con- trol. Solution of melanin pigments was able to enhance the functional activity of bone marrow of irradiated ani- mals. Obtained results of radioprotective action of basidiomycotic melanin pigments solution on irradiated stem cells and their descendants (progenitor cells) may become the evidence for development of the protective means for human organism from the injuring action of ionizing radiation.

Purification, structural characterization and anti-UVB irradiation activity of an extracellular polysaccharide from Pantoea agglomerans.

Extracellular polysaccharide (EPS) produced by Pantoea agglomerans was purified for structural analysis and anti-UVB activity evaluation. The results showed that the EPS comprised of mannose and glucose in a ratio of 3:2. The molecular weight of EPS was estimated as 679 KDa. Fourier transform infrared spectrometry (FT-IR) showed that the EPS was composed of d-furanose without any substituent group. The structure of the EPS could be deduced as a repeated pentasaccharide arranged of three mannose molecules and two glucose molecules according to electrospray ionization mass spectrometry (ESI-MS) analysis and results mentioned above. The results also showed that the EPS attenuated UVB-induced cytotoxicity which was verified by morphology feature assay, down-regulated the expression of phosphor-JNK and active caspase3 significantly through MAPK pathway in UVB-irradiated HaCaT cells, and therefore protected the cells from apoptosis which could be identified by the lower apoptosis rate at low dose of UVB ray. In conclusion, the EPS as a macromolecule arranged by repeated pentasaccharide could protect HaCaT keratinocytes from UVB irradiation injury effectively, and the underlying mechanism may involve MAPK signaling pathway which contribute to apoptotic cell death. However, further studies on efficacy of the EPS in vivo are needed to determine.

Streptomyces sp. MUM273b: A mangrove-derived potential source for antioxidant and UVB radiation protectants.

Microbial natural products serve as a good source for antioxidants. The mangrove-derived Streptomyces bacteria have been evidenced to produce antioxidative compounds. This study reports the isolation of Streptomyces sp. MUM273b from mangrove soil that may serve as a promising source of antioxidants and UV-protective agents. Identification and characterization methods determine that strain MUM273b belongs to the genus Streptomyces. The MUM273b extract exhibits antioxidant activities, including DPPH, ABTS, and superoxide radical scavenging activities and also metal-chelating activity. The MUM273b extract was also shown to inhibit the production of malondialdehyde in metal-induced lipid peroxidation. Strong correlation between the antioxidant activities and the total phenolic content of MUM273b extract was shown. In addition, MUM273b extract exhibited cytoprotective effect on the UVB-induced cell death in HaCaT keratinocytes. Gas chromatography-mass spectrometry analysis detected phenolics, pyrrole, pyrazine, ester, and cyclic dipeptides in MUM273b extract. In summary, Streptomyces MUM273b extract portrays an exciting avenue for future antioxidative drugs and cosmeceuticals development.

Radioprotective Effect of Walnut Oligopeptides Against Gamma Radiation-Induced Splenocyte Apoptosis and Intestinal Injury in Mice.

Walnut oligopeptides (WOPs) intake is associated with the augment of the antioxidant defense system and immune system. The chief object of this study is to evaluate the radioprotective effect of walnut oligopeptides extracted from walnut seed protein against 60Coγ-irradiation induced damage in mice. Female BALB/c mice were administered WOPs through drinking water for 14 days until a single dose of whole-body 60Coγ-irradiation. The 30-day survival test was carried out in the first group (8 Gy), and the other two groups (3.5 Gy) were sacrificed at 3 days and 14 days post-irradiation. Blood and organ samples of mice in the three groups were collected, the histopathological analysis and immunohistochemistry were conducted. The number of peripheral blood leukocytes, bone marrow DNA content, inflammatory cytokines, antioxidant capacity, and intestinal permeability were measured. We found that the administration of WOPs augmented antioxidant defense system, accelerated hematopoietic recovery and showed the significant trend toward higher survival rate and less weight loss compared with non-administrated control mice. In addition, WOPs administration appeared to be important to limit IR-induced splenocyte apoptosis and inflammatory cascade as well as reduce intestine epithelial barrier dysfunction and promote epithelial integrity. These results suggest that pre and post-treatment of WOPs may help to ameliorate acute damage, which is induced by ionizing radiation in mice and accelerate its recovery.

Reduction of Gamma Radiation-Induced Damage by Hydro-Alcoholic Extract of Nardostachys jatamansi.

The search for a nontoxic radioprotector has not yielded any promising results. Many antioxidant compounds, though effective under in vitro conditions as radioprotectors, have failed under in vivo settings due to their toxicity. The Indian medical system of Ayurveda uses a variety of plants with antioxidant potential, and these may be harboring molecules with radioprotective properties. In the present work, the radioprotective property of Nardostachys jatamansi was investigated. A hydro-alcoholic extract of this plant provided protection to the cellular DNA and membrane from 4 Gy gamma radiation. Depletion of cellular antioxidant status was also prevented by this extract. Molecular-level analysis in the intestines of mice revealed a lower bax/bcl2 ratio suggestive of a reduction of radiation-induced apoptosis. Expression levels of the DNA repair gene atm were elevated, along with a reduction in the expression of the inflammatory gene cox2. The extract also provided a survival advantage to mice exposed to lethal doses of gamma radiation. These results suggest a possible radioprotective role for Nardostachys jatamansi.

Role of acemannan O-acetyl group in murine radioprotection.

Present study was designed to investigate the role of acemannan acetyl group in murine radioprotection. Acemannan, extracted from Aloe vera gel, has molecular weight of 1.02 × 106 Da and mainly composed of mannose (84.9%), glucose (7.2%), and galactose (3.9%), with backbone of (1→4)-linked mannose and glucose. Acemannan was over-acetylated and deacetylated to investigate the role of acetyl group. Acetylation enhances acemannan viscosity and thermal stability. Free radicals scavenging and Fenton reaction inhibition was mediated by acemannan acetyl and hydroxyl group respectively. Native or over-acetylated or deacetylated acemannan pre-treatment to mice has shown to reduce the γ-radiation-induced oxidative damage, and hematopoietic injuries by free radical scavenging and microphage activation (secretes pro-hematopoietic factors through TLR-4) respectively. Over-acetylated acemannan has stronger effects on immunomodulation/radioprotection. In summary, acemannan acetyl-group modulates immune system, while hydroxyl-group participate in free radical scavenging, and present finding can be employed in food and pharma industries for enhancing polysaccharide bioactivity.

Asperyellone pretreatment protects HaCaT cells from UVB irradiation induced oxidative damages: Assessment under in vitro and in vivo conditions and at molecular level.

The present study explores the UVB protective role of Asperyellone (AY), a secondary metabolite of Aspergillus niger strain AN01. The in vitro UVB protective efficacy of AY was studied using the Human Epidermal keratinocytes cells (HaCaT) cell line. The results suggest the appreciable scavenging of UVB-induced reactive oxygen species in the AY-pretreated cells compared with UVB control. Experimental results on the antioxidant enzymes (Catalase, SOD, LPO, and GPx) profile, histochemical, and molecular analyses support the UVB protective effect of AY in HaCaT cells. Further, the in vivo UVB protective efficacy of AY was studied using animal models and compared with that of commercially available UVB protective agents. Physical, biochemical, and molecular analyses of skin samples emphasized the UVB protective role of AY. Thus, the important beneficial effects of AY have been explored in the present study.

Structure, Molecular Modification, and Anti-radiation Activity of Melanin from Lachnum YM156 on Ultraviolet B-Induced Injury in Mice.

The purpose of this study was to examine the protective effects of intracellular homogeneous melanin produced by Lachnum YM156 (LIM) against ultraviolet B (UVB) induced damage in mice. The possible structural formula of the LIM was concluded based on elemental analysis, ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and mass spectrometry (MS). The LIM was modified by arginine to improve its water solubility and biological activities. LIM and ALIM show significant anti-radiation activity in which LIM and ALIM protect the skin under UV radiation. Results indicate that activities of anti-oxidant enzymes in skin were improved after treatment of LIM or ALIM. In addition, LIM and ALIM inhibited over expression of the pro-inflammatory cytokines, including interleukin (IL)-1α, IL-1ß, and IL-6 and tumor necrosis factor-α (TNF-α). The protection ability of ALIM was higher than that of LIM at the same dose. Thus, applied LIM and ALIM may be a promising radiation-protective agent.

Protection against UVB-induced damages in human dermal fibroblasts: efficacy of tricin isolated from enzyme-treated Zizania latifolia extract.

This study was undertaken to determine the effects of enzyme-treated Zizania latifolia (ETZL) and of its major compound tricin on skin photo-aging and to investigate the mechanisms involved. It was found ETZL and tricin suppressed matrix metalloproteinase (MMP) production and increased type I-procollagen production in UVB-irradiated human dermal fibroblasts (HDFs). Furthermore, ETZL and tricin significantly up-regulated the expressions of the antioxidant enzymes HO-1 and SOD1, reduced UVB-induced reactive oxygen species (ROS) generation and mitogen-activated protein kinase (MAPK) induction by ROS and thereby attenuated activator protein-1 (AP-1) expression. In addition, ETZL and tricin both reduced the phosphorylations of IκBα and IKKα/ß and κB blocked the nuclear translocation of nuclear factor-κB (NF-κB) p65. These results show that ETZL have skin protective effects against UVB and suggest tricin as major efficacious material in ETZL protecting skin photoaging.

Comparison on characterization and antioxidant activity of polysaccharides from Ganoderma lucidum by ultrasound and conventional extraction.

The polysaccharides of Ganoderma lucidum (GLP) extracted by the methods of ultrasound assisted extraction (UAE) and hot water extraction (HWE) were characterized and the antioxidant activities of GLPUAE and GLPHWE were compared. High performance gel permeation chromatography (HPGPC) showed that the average molecular weight of GLPUAE and GLPHWE were 465.65 kDa and 703.45 kDa, respectively. GLPUAE was composed of mannose, rhamnose, glucose, galactose and arabinose in the molar ratio of 2.58:1.25:11.17:2.5:1, while GLPHWE was composed of the same monosaccharide in the ratio of 3.11:1.11:19.44:2.33:1. GLPHWE showed a relatively higher antioxidant activity than GLPUAE by testing the reducing power, the scavenging ability on 1.1­diphenyl­2­picryl­hydrazyl (DPPH), hydroxyl radical and cellular protective effect on yeast cells from ultraviolet radiation (UV) damage. GLPUAE and GLPHWE were purified by chromatographic column of DEAE-52 cellulose. GLPUAE, GLPHWE and the purified components could be novel antioxidants for functional food.

Flavonol glycosides in Dyssodia tagetiflora and its temporal variation, chemoprotective and ameliorating activities.

Dyssodia tagetiflora is known as 'Tzaracata' and 'flor de muerto'. Recently, D. tagetiflora has been reported to have antioxidant activities in its polar extracts as well as insecticidal activities. Hyperoside (1), avicularin (2) and avicularin acetate (3) have been isolated previously. However, the temporary variation in glycoside flavonoids biosynthesis, as well as antibacterial and chemoprotective activities, have not been reported. The amount of 1, 2 and 3 in the different collections was characterized by HPLC-MS. Two new C-glycosides were characterized, quercetin-4'-methyl ether 6-C glucoside (A1) and quercetin-4'-methyl ether 8-C glucoside (A2), as well as [2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-4-oxochromen-3-yl]3,4,5-trihydroxyoxane-2,6-dicarboxylate (A3). This is the first report of the presence of C-C flavonoid glycosides compounds in the genus Dyssodia. Hyperoside was the majority compound at all collections. The methanolic extracts of August 2016 and October 2017 were active against Micrococcus luteus and Bacillus subtillis. The methanolic extract has chemoprotective effects because, when applied topically in SKH-1 mice, it decreases the severity of epidermal damage induced by acute exposure to ultraviolet radiation. In addition, cutaneous photocarcinogenesis was decreased in mice treated with the extract. The methanolic extract of D. tagetiflora has chemoprotective properties by decreasing the damage caused by acute and chronic exposure to UV in mice.

Hydroxytyrosol from olive fruits prevents blue-light-induced damage in human keratinocytes and fibroblasts.

Skin aging is a complex biological process influenced by a combination of endogenous or intrinsic and exogenous or extrinsic factors due to environmental damage. The primary environmental factor that causes human skin aging is the ultraviolet irradiation from the sun. Recently, it was established that the long-term exposure to light-emitting-diode-generated blue light (LED-BL) from electronic devices seems to have a relevant implication in the molecular mechanisms of premature photoaging. BL irradiation induces changes in the synthesis of various skin structures through DNA damage and overproduction of reactive oxygen species (ROS), matrix metalloproteinase-1 and -12, which are responsible for the loss of the main components of the extracellular matrix of skin like collagen type I and elastin. In the current study, using human keratinocytes and fibroblasts exposed to specific LED-BL radiation doses (45 and 15 J/cm 2 ), we produced an in vitro model of skin photoaging. We verified that, compared with untreated controls, the treatment with LED-BL irradiation results in the alteration of metalloprotease-1 (collagenase), metalloprotease-12 (elastase), 8-dihydroxy-2'-deoxyguanosine, proliferating cell nuclear antigen, and collagen type I. Moreover, we showed that the photoaging prevention is possible via the use of hydroxytyrosol extracted from olive fruits, well known for antioxidant properties. Our results demonstrated that hydroxytyrosol protects keratinocytes and fibroblasts from LED-BL-induced damage. Thus, hydroxytyrosol might be proposed as an encouraging candidate for the prevention of BL-induced premature photoaging.