luteolin-7-O-glucoside Research Articles

Antioxidant and Compositional HPLC Analysis of Three Common Bamboo Leaves.

Bamboo leaves of Phyllostachys nigra (PN), Lophatherum gracile (LG), and Pleioblastus amarus (PA) are three common herbs in China. In this work, a new high performance liquid chromatography (HPLC) method for the simultaneous determination of seven compounds in bamboo leaves has been developed; and PN, LG, and PA leaves were analyzed. PN showed four times as much chlorogenic acid (CA) than the other two, and contained the most isoorientin (iso-ORI) and isovitexin (iso-VIT) as well. The PA presented the most orientin (ORI) and LG covered a majority of cynaroside (CYN). We measured the antioxidant activity by scavenging the stable 2,2-diphenyl-1-pyridinohydrazinyl (DPPH) free radicals, and found that Luteolin (inhibitory concentration (IC)50 = 0.42 µM, LUT) and CYN (IC50 = 0.43 µM) showed 2–3 times higher antioxidant activity than iso-ORI (IC50 = 0.81 µM), ORI (IC50 = 0.84 µM), and other related antioxidant standards such as trolox (IC50 = 0.97 µM) and ascorbic acid (IC50 = 0.93 µM, VC). Among extracts, PN and PA showed considerable antioxidant activity, which was related well with the contents of CA, iso-ORI, and iso-VIT (p < 0.05). This study firstly provides evidence for functional antioxidant compounds of bamboo leaves based on statistical analysis of the HPLC analysis and DPPH assay, and it lays a foundation for its further development or utilization.

The antioxidant system in Olea europaea to enhanced UV-B radiation also depends on flavonoids and secoiridoids

The Mediterranean crop Olea europaea is often exposed to high UV-B irradiation conditions. To understand how this species modulates its enzymatic and non-enzymatic antioxidant system under high UV-B radiation, young O. europaea plants (cultivar “Galega Vulgar”) were exposed, for five days, to UV-B radiation (6.5 kJ m−2 d−1 and 12.4 kJ m−2 d−1). Our data indicate that UV-doses slightly differ in the modulation of the antioxidant protective mechanisms. Particularly, superoxide dismutase (SOD), guaiacol peroxidase (GPox) and catalase (CAT) activities increased contributing to H2O2 homeostasis, being more solicited by higher UV-B doses. Also, glutathione reductase (Gr) activity, ascorbate (AsA) and reduced glutathione (GSH) pools increased particularly under the highest dose, suggesting a higher mobilization of the antioxidant system in this dose. The leaf metabolites’ profile of this cultivar was analysed by UHPLC-MS. Interestingly, high levels of verbascoside were found, followed by oleuropein and luteolin-7-O-glucoside. Both UV-B treatments affected mostly less abundant flavonoids (decreasing 4ʹ-methoxy luteolin and 4ʹ or 3ʹ-methoxy luteolin glucoside) and hydroxycinnamic acid derivatives (HCAds, increasing β-hydroxyverbascoside). These changes show not only different mobilization with the UV-intensity, but also reinforce for the first time the protective roles of these minor compounds against UV-B, as reactive oxygen species (ROS) scavengers and UV-B shields, in complement with other antioxidant systems (e.g. AsA/GSH cycle), particularly for high UV-B doses. Secoiridoids also standout in the response to both UV-B doses, with decreases of oleuropein and increases 2ʹʹ-methoxyoleuropein. Being oleuropein an abundant compound, data suggest that secoiridoids play a more important role than flavonoids and HCAds, in O. europaea protection against UV-B, possibly by acting as signalling molecules and ROS scavengers. This is the first report on the influence of UV-B radiation on the secoiridoid oleuropein, and provides a novel insight to the role of this compound in the O. europaea antioxidant defence mechanisms.

Phytochemical profile, antioxidant and antiproliferative activities of olive leaf extracts from autochthonous Tunisian cultivars

The aim of the present study was to investigate the biological activities of Tunisian olive leaf extracts and to correlate these activities to their phytochemical composition. The phenolic profile of four Tunisian autochthonous cultivars Chemlali, Sayali, Neb jmel, and Meski was determined using LC/MS-MS. The antioxidant activity of olive leaf extracts was evaluated using DPPH test. The antiproliferative effect was also investigated using MTT assay. The phytochemical screening showed that phenolic content and phenolic class repartition were significantly affected by olive leaf cultivars. Twenty-one components were identified and oleurpein, luteolin 4-glucoside, luteolin 7-glucoside, and apigenin 7-glucoside were the major phenolic components. Among all extracts, Sayali exhibited the strongest antioxidant and antiproliferative activities (IC50 41.36 µg ml−1 / EC50 147.11 µg ml−1). The MTT result showed that olive leaf extract reduced MCF-7 cell viability in a dose-dependent manner. Western blot analysis demonstrated that olive leaf extracts exhibited antiproliferative activity through apoptosis induction.

Luteolin-7-O-glucoside protects dopaminergic neurons by activating estrogen-receptor-mediated signaling pathway in MPTP-induced mice

BackgroundParkinson's disease (PD) is a neurodegenerative disorder that is characterized by the degeneration of dopaminergic neurons in substantia nigra (SN). Accumulating evidences implicate the beneficial role of estrogen in the therapy of PD. MethodsIn the present study, the protective function of luteolin-7-O-glucoside (LUT-7G), a natural flavonoid, was investigated in 1-methyl-4-phenylpyridinium (MPP+) treated SH-SY5Y cells and 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) induced mice. ResultsPre-treatment of LUT-7G increased the viability and reduced the apoptosis of SH-SY5Y cells treated by MPP+. At molecular level, the Bcl-2/Bax ratio was increased, while the expression of cleaved caspase 3 was markedly lessened. Moreover, LUT-7G increased the expression of estrogen receptor (ER), ERα and ERβ, and enhanced the activation of ERK1/2/STAT3/c-Fos that could be abolished by ER antagonists. Furthermore, in vivo experiment indicated that pre-treatment of LUT-7G improved the bradykinesia, and enhanced the muscle strength as well as the balancing capacity of mice treated with MPTP. And LUT-7G prevented the injury of TH positive cells in substantia nigra and increased TH positive nerve fibers in striatum. In addition, pre-treatment of LUT-7G also significantly diminished the MPTP-induced gliosis in substantia nigra. ConclusionsLUT-7G effectively protected dopaminergic neurons against MPP+ or MPTP-induced toxicity, probably by activating the ER-mediated signaling pathway. Our findings explore the therapeutic potential of LUT-7G for PD therapy.

Liquid chromatography fingerprint analysis and antioxidant activity of selected lavender species with chemometric calculations.

The extracts of seven Lavandulae species (Lavandula stoechas, Lavandula lanata, Lavandula viridis, Lavandula angustifolia „Rosea”, Lavandula angustifolia „Afropurpurea”, Lavandula angustifolia and one unknown) were analyzed using the reversed-phase-high performance liquid chromatography–diode array detection (RP-HPLC–DAD) with gradient elution technique to obtain the chromatographic fingerprint profiles. The HPLC analysis was performed using the Kinetex RP18 chromatographic column and eluent consisting of methanol-water-0.1% formic acid (5–100% (v/v)) at 30 °C with the run time of 60 min. and the detection wavelength 280 nm. The chromatograms were preliminary processed with the smoothing, noise reduction, background subtraction and alignment using the SpecAlign program (version 2.4.1). The presence of selected standards (apigenin, myricetin, luteolin, luteolin 7-glucoside, chlorogenic acid, caffeic acid, ferulic acid) in the extracts was confirmed. The chemical similarity between studied plants was evaluated using the Cluster Analysis (Pearson correlation coefficient, r, and Euclidean) and PCA. The preliminary antioxidant activity of studied extracts was evaluated based on the total phenolic content (Folin-Ciocalteu method), ferric ion reducing antioxidant parameter (FRAP) and α,α-diphenyl-β-picrylhydrazyl (DPPH) free radical scavenging method using the spectrophotometric technique.

Assessment of selected Saudi and Yemeni plants for mosquitocidal activities against the yellow fever mosquito Aedes aegypti

As part of our continuing investigation for interesting biological activities of native medicinal plants, thirty-nine plants, obtained from diverse areas in Saudi Arabia and Yemen, were screened for insecticidal activity against yellow fever mosquito Aedes aegypti (L.). Out of the 57 organic extracts, Saussurea lappa, Ocimum tenuiflorum, Taraxacum officinale, Nigella sativa, and Hyssopus officinalis exhibited over 80% mortality against adult female Ae. aegypti at 5 μg/mosquito. In the larvicidal bioassay, the petroleum ether extract of Aloe perryi flowers showed 100% mortality at 31.25 ppm against 1st instar Ae. aegypti larvae. The ethanol extract of Saussurea lappa roots was the second most active displaying 100% mortality at 125 and 62.5 ppm. Polar active extracts were processed using LC-MS/MS to identify bioactive compounds. The apolar A. perryi flower extract was analyzed by headspace SPME-GC/MS analysis. Careful examination of the mass spectra and detailed interpretation of the fragmentation pattern allowed the identification of various biologically active secondary metabolites. Some compounds such as caffeic and quinic acid and their glycosides were detected in most of the analyzed fractions. Additionally, luteolin, luteolin glucoside, luteolin glucuronide and diglucuronide were also identified as bioactive compounds in several HPLC fractions. The volatile ketone, 6-methyl-5-hepten-2-one was identified from A. perryi petroleum ether fraction as a major compound.

Luteolin-7-glucoside Promotes Human Epidermal Stem Cell Proliferation by Upregulating β-Catenin, c-Myc, and Cyclin Expression.

Skin epidermal stem cells (EpSCs) play critical roles in skin homeostasis and the repair of skin injury. Luteolin-7-glucoside (L7G) has been reported to accelerate skin wound healing through its anti-inflammatory and antioxidative activity. But its effect on EpSCs is not clear. In the present study, we examined the effect of L7G on the proliferation of human EpSCs and explored the mechanisms involved. MTT assay showed that L7G promoted EpSC proliferation in a dose- and time-dependent manner. BrdU incorporation assay and Ki67 immunofluorescence staining confirmed the proproliferative effect of L7G on EpSCs. Cell cycle analysis showed that treatment of EpSCs with L7G decreased the cell number in the G1 phase and increased the cell number in the S phase. In addition, L7G significantly enhanced EpSC migration. Mechanistic studies showed that L7G significantly induced the expression of β-catenin and c-Myc, as well as cyclins D1, A2, and E1 which are critical for G1/S phase transition. L7G stimulated EpSC proliferation through β-catenin and c-Myc. We further examined the effect of L7G on EpSC proliferation in skin tissues by treatment of human skin explants with L7G and examined the number of EpSCs by immunohistochemical stain of EpSC markers α6 integrin and β1 integrin. We found that treatment of human skin tissue explants with L7G significantly increased the thickness of the epidermis and increased the numbers of α6 integrin-positive and β1 integrin-positive cells at the basal layer of the epidermis. Taken together, these results indicate that L7G promotes EpSC proliferation through upregulating β-catenin, c-Myc, and cyclin expression. L7G can be used to expand EpSCs for generating epidermal autografts and engineered skin equivalents.

In silico exploration the phenolic compound of olive leaves as acetylcholinesterase enzyme (AChE) inhibitor for Alzheimer’s disease therapy

Olive (Olea europaea) have been cultivated and grown well in tropical climates such as Indonesia. Indonesia local community have used olive as herbal medicines due to its active compounds known as oleuropein that has many biological activities including as neurotherapy in Alzheimer's disease. The purpose of this study is to explore the potential phenolic compounds of olive and examine the acetylcholinesterase (AChE) inhibitory activity displayed by different olive polyphenols through a silico approach. The bioactive compounds of olive which had been analyzed in this study were phenolic compound included oleuropein, demethyl-oleuropein, ligstroside, oleoside, verbascoside, luteolin 7-glucoside, and hydroxytyrosol. Interaction of bioactive compounds with acetylcholinesterase (AChE) was analyzed through molecular specific docking using AutoDock Vina with Pyrx Software. The result elucidate that olive contain potential biological activities as antioxidant, anti-inflammatory, antineoplastic, free radical scavenger, antibacterial, antifungal, expression TP53 enhancer, caspase 8 stimulant, platelet adhesion inhibitor, treatment for lipoprotein disorder, antiviral and dementia treatment/Alzheimer disease. The highest bioactivity percentage of olive phenolic compound are as an antioxidant of 82%, anti-inflammatory of 73%, and anti-cancer (antineoplastic) of 70% respectively. Based on molecular docking analysis show one of olive phenolic compound of the dimethyl-oleuropein has strong interaction with AChE as pointed in the binding affinity of demethyl-oleuropein +AChE of -8.9 kcal/mol has closed to galanthamine binding affinity of -10.3 kcal/mol. Along with glutamate acid 202, tyrosine 133 and tyrosine 124 are the major contributors in the target-ligand interactions. The selected demethyl-oleuropein ought to be tested in clinical studies to discover new neuro-therapeutic candidates.

Luteolin-7-O-β-d-Glucoside Inhibits Cellular Energy Production Interacting with HEK2 in Keratinocytes.

Flavonoids have been demonstrated to affect the activity of many mammalian enzyme systems. Their functional phenolic groups are able to mediate antioxidant effects by scavenging free radicals. Molecules of this class have been found able to modulate the activity of kinases, phospholipase A2, cyclooxygenases, lipoxygenase, glutathione S-transferase, and many others. Recently, it has been demonstrated that luteolin, in the form of Luteolin-7-O-β-d-glucoside (LUT-7G) is able to induce the keratinocyte differentiation process in vitro. This flavonoid is able to counteract the proliferative effects of IL-22/IL6 pathway by the inhibition of STAT3 activity also in vivo in a psoriatic mouse model. Observations on energy metabolism changes of differentiating cells led us to perform a complete metabolomics analysis using human primary keratinocytes treated with LUT-7G. Our results show that LUT-7G, is not only able to impair the nuclear translocation of STAT3, but it also blocks the energy metabolism pathway, depressing the glycolytic and Krebs pathway by the inhibition of hexokinase 2 activity. These data confirm that LUT-7G can be proposed as a potential candidate for the treatment of inflammatory and proliferative diseases, but its role as a hexokinase 2 (HEK2) inhibitor opens new perspectives in nutritional science, and especially in cancer therapy, in which the inhibition of the Warburg effect could be relevant.

Genotype-Related Differences in the Phenolic Compound Profile and Antioxidant Activity of Extracts from Olive (Olea europaea L.) Leaves.

The phenolic compound contents and antioxidant activities of the leaf extracts of nine olive genotypes were determined, and the obtained data were analysed using chemometric techniques. In the crude extracts, 12 compounds belonging to the secoiridoids, phenylethanoids, and flavonoids were identified. Oleuropein was the primary component for all genotypes, exhibiting a content of 21.0 to 98.0 mg/g extract. Hydroxytyrosol, verbascoside, luteolin 7-O-glucoside, and luteolin 4′-O-glucoside were also present in noticeable quantities. Genotypes differed to the greatest extent in the content of verbascoside (0.45–21.07 mg/g extract). The content of hydroxytyrosol ranged from 1.33 to 4.03 mg/g extract, and the aforementioned luteolin glucosides were present at 1.58–8.67 mg/g extract. The total phenolic content (TPC), DPPH• and ABTS•+ scavenging activities, ferric reducing antioxidant power (FRAP), and ability to inhibit the oxidation of β-carotene-linoleic acid emulsion also varied significantly among genotypes. A hierarchical cluster analysis enabled the division of genotypes into three clusters with similarity above 60% in each group. GGE biplot analysis showed olive genotypes variability with respect to phenolic compound contents and antioxidant activities. Significant correlations among TPC, FRAP, the values of both radical scavenging assays, and the content of oleuropein were found. The contents of 7-O-glucoside and 4′-O-glucoside correlated with TPC, TEAC, FRAP, and the results of the emulsion oxidation assay.

Improving the contents of the active components and bioactivities of Chrysanthemum morifolium Ramat.: The effects of drying methods

The effect of drying methods were evaluated including hot air drying (HD), blanching-hot air drying (BHD), shade drying, microwave-hot air drying (MHD), freeze drying (FD), and vacuum-hot air drying (VHD) on the quality and bioactivities of chrysanthemum flowers. HD had the lowest total flavonoid values due to the reaction between flavonoids and oxidase during drying. Reduced activities of polyphenol oxidase and peroxidase in samples from MHD and BHD suggested that they are effective at inhibiting enzymatic browning, while the BHD could lead to the loss of some water-soluble components. Microwave treatment for 30 s combined with 75 °C hot air drying was the most effective treatment in preserving biologically active compounds, resulting in higher antioxidant capacity and greater inhibition of the enzyme acetylcholinesterase (AChE). FT-IR showed that the BHD, microwave treatment for 90 s, and VHD led to loss of more compounds than FD. This study also found that 3,5-di-caffeoylquinic acid (3,5-DCQA), luteolin-7-O-glucoside (LuG), luteolin, and kaempferol were the key bioactive substances inhibiting AChE. Furthermore, molecular docking studies showed that a high inhibition of AChE by 3,5-DCQA and LuG could be attributed to the formation of strong hydrogen bonds. The study may be beneficial for understanding C. morifolium's nutritional value and the effects of drying methods on the quality of the final product.

Research of Luteoloside in promoting proliferation and migration of human epidermal stem cells

Objective To investigate the effects of Luteoloside on the proliferation and migration of human epidermal stem cells (EpSCs) and the proliferation of epidermal cells in skin tissue in vitro. Methods EpSCs were isolated from human skin tissue by type Ⅳ collagenase digestion and collagen fast adherence. EpSCs were identified by immunofluorescence staining of CK19 and β1 integrin. The effects of Luteoloside (0 to 5.0 μmol/L) on the proliferation of EpSCs were measured by MTT assay. The effects of Luteoloside on EpSCs migration and wound healing were observed by scratch-wound model in vitro. The effects of Luteoloside on the thickness of epidermis in vitro were observed by HE staining. Results EpSCs formed a cobblestone-shaped cell monolayer when cultured on a collagen coated dish. Immunofluorescence staining showed that more than 90% cells were CK19 and β1 integrin positive. Luteoloside at 0.1 to 1.0 μmol/L could significantly promote the EpSCs proliferation; Luteoloside at 1.0 μmol/L could significantly enhance EpSCs migration and scratch healing. Culture of skin tissues with 1.0 μmol/L Luteoloside for 5 days could significantly increase the thickness of the epidermis. Conclusion Luteoloside can promote the proliferation and migration of EpSCs, promote the proliferation of epidermal tissue, and play an important role in skin self-renewal and injury repair. Key words: Cell proliferation; In vitro; Luteoloside; Epidermal stem cells; Migration

Biological activities, isolated compounds and HPLC profile of Verbascum nubicum

Context: Genus Verbascum (Scrophulariaceae) comprises about 360 species of flowering plants. Verbascum has been used in traditional medicine as an astringent, antitussive, analgesic and anti-inflammatory.Objective: Nothing was found in the available literature concerning Verbascum nubicum Murb; therefore, the study evaluates the biological activities, isolated compounds and HPLC profile.Materials and methods: Methanol extract (VME) and butanol fraction (VBF) of air-dried powdered V. nubicum were obtained. Four compounds were isolated from VBE and identified by 1H- and 13C-NMR. High-performance liquid chromatography (HPLC) profile was determined for (VME). LD50, in vitro antioxidant, in vivo antiulcerogenic and anti-inflammatory activities as well as hepatoprotective activity were assessed. Anti-ulcerogenic and hepatoprotective activities were supported by histopathological examinations.Results: HPLC analysis of VME revealed the presence of luteolin 7-glucoside (2215.43 mg/100 g), hesperidin (954.51 mg/100 g) and apigenin (233.15 mg/100 g) as major compounds. Four compounds were isolated and confirmed by NMR data, were identified as gentiopicroside, luteolin, aucubin and gallic acid. The LD50 of VME and VBF extracts were calculated to be 8200 and 4225 mg/kg b.w., respectively. IC50 values of VBE and VMF as measured by DPPH·method were 43.6 and 50 µg/mL, respectively. Also, anti-inflammatory effect of VME (400 mg/kg b.w.) and VBF (200 mg/kg b.w.) induced edema model after 120 min were 61.93 and 56.13%, respectively. Antiulcerogenic activity of VME (400 mg/kg b.w.) and VBF (200 mg/kg b.w.) in albino rats were 65.14 and 84.57%, respectively.Conclusions: The V. nubicum extracts displayed safe and promising antioxidant, anti-inflammatory and hepatoprotective properties. It can be also applied in the pharmacy industry, food industry and healthcare.

Enzymatic synthesis of α-flavone glucoside via regioselective transglucosylation by amylosucrase from Deinococcus geothermalis.

α-Flavone glycosides have beneficial properties for applications in the pharmaceutical, cosmetic, and food industries. However, their chemical syntheses are often limited by a low efficiency or scarcity of substrates. In this study, α-flavone glucosides were enzymatically synthesized by amylosucrase from Deinococcus geothermalis (DGAS) using sucrose and various flavones as a donor for glucosyl units and acceptors, respectively. Luteolin was the most effective acceptor in the transglucosylation reaction using DGAS among nine flavone materials (apigenin, chrysin, 6,7-dihydroxyflavone, homoorientin, 7-hydroxyflavone, isorhoifolin, luteolin, luteolin-3′,7-diglucoside, and orientin). The highest production yield of luteolin glucoside was 86%, with a 7:1 molar ratio of donor to acceptor molecules, in 50 mM Tris-HCl buffer (pH 7) at 37°C for 24 h using 2 U of DGAS. The synthesized luteolin glucoside was identified as luteolin-4′-O-α-D-glucopyranoside with a glucose molecule linked to the C-4′ position on the B-ring of luteolin via an α-glucosidic bond, as determined by 1H and 13C nuclear magnetic resonance. This result clearly confirmed that the glucosylated luteolin was successfully synthesized by DGAS and it can be applied as a functional ingredient. Furthermore, this approach using DGAS has the potential to be utilized for the synthesis of various glucosylated products using different types of polyphenols to enhance their functionalities.

Absorption and Metabolism of Luteolin in Rats and Humans in Relation to in Vitro Anti-inflammatory Effects

Luteolin is a flavonoid present in plants in the form of aglycone or glucosides. In this study, luteolin glucosides (i.e., luteolin-7- O-β-d-glucoside, luteolin-7- O-[2-(β-d-apiosyl)-β-d-glucoside], and luteolin-7- O-[2-(β-d-apiosyl)-6-malonyl-β-d-glucoside]) prepared from green pepper leaves as well as luteolin aglycone were orally administered to rats. Regardless of the administered luteolin form, luteolin glucuronides were mainly detected from plasma and organs. Subsequently, luteolin aglycone, the most absorbed form of luteolin in rats, was orally administered to humans. As a result, luteolin-3'- O-sulfate was mainly identified from plasma, suggesting that not only luteolin form but also animal species affect the absorption and metabolism of luteolin. When LPS-treated RAW264.7 cells were treated with luteolin glucuronides and luteolin sulfate (the characteristic metabolites identified from rats and humans, respectively), the different luteolin conjugates were metabolized in different ways, suggesting that such difference in metabolism results in their difference in anti-inflammatory effects.

Chemcial constituents of Eclipta prostrata

A total of twenty-two compounds were isolated from the 95% EtOH extract of Eclipta prostrata by various purification steps, and their structures were established as ecliptalignin A (1)，ecliptasaponin Ⅰ (2), ecliptasaponin Ⅱ (3), echinocystic acid (4), 3-oxo-16α-hydroxy-olean-12-en-28-oic acid (5), acacetin-7-O-rutinoside (6), luteoloside (7), apigenin (8), luteolin (9), acacetin (10), skullcapflavone Ⅱ (11), kaempferol (12), kaempferide (13), quercetin (14), 4',7-dihydroxyl-3',6'-dimethoxylisoflavone-7-O-glucoside (15), ecliptal (16), 5-hydroxymethyl-(2,2',5',2″)-terthienyl tiglate (17), psoralen (18), isopsoralen (19), wedelolactone (20), crinumaquine (21), and 2,3,9,12-tetramethoxyprotoberberine (22) mainly based on the spectroscopic techniques, of which 1 was a new lignin analogue, and 5, 6, 10-13, 15, 18, 19, 21 and 22 were isolated form this plant for the first time.

Protection of Luteolin-7-O-glucoside against apoptosis induced by hypoxia/reoxygenation through the MAPK pathways in H9c2 cells.

Myocardial hypertrophy is often associated with myocardial infarction. Luteolin-7-O-glucoside (LUTG) has the prosperity of preventing cardiomyocyte injury. The current study aimed to explore the potential protective effect of LUTG and its relevant mechanisms in the heart. To establish the cardiac hypertrophy model in vitro, Angiotensin II (Ang II) was used to stimuli H9c2 cells in this study. The CCK-8 assay showed that LUTG pretreatment improved cell viability of cardiomyocytes co-treated with Ang II and ischemia/reperfusion. LUTG decreased the reactive oxygen species levels. Furthermore, it was demonstrated LUTG could reduce the release amount of lactate dehydrogenase and recover the catalase activity according to the flow cytometry analysis, and activity detection, respectively in Ang II-H/R-treated H9c2 cells. In addition, the flow cytometry analysis showed that the pretreatment of LUTG mitigated cell apoptosis induced by hypoxia/reoxygenation in the cardiac hypertrophy model. Meanwhile, reverse transcription-quantitative polymerase chain reaction and western blot assays showed that the apoptosis-related genes, including poly (ADP-ribose) polymerase, Fas, Fasl and Caspase-3 were downregulated at the transcriptional and translational levels. Notably, the protien expression of phosphorylated (p)-extracellular signal-regulated kinas (ERK) 1/2, p-janus kinase and p-P38 were reduced, while the expression of p-ERK5 was elevated in the LUTG pretreatment groups compared with the hypoxia/reoxygenation treatment group. Based on these results, it was suggested that the anti-apoptosis effect of LUTG may be associated with regulating the activation of mitogen-activated protein kinases signaling pathways.

Effect of Sunlight Radiation on the Growth and Chemical Constituents of Salvia plebeia R.Br.

This study investigated the chemical composition changes of Salvia plebeia R.Br. cultivated under different light sources, including florescent light and sunlight. The plants were exposed to fluorescent light for four months and sunlight and then examined for the next 5–7 months. Plants were harvested monthly during the seven months, and we examined whether the difference in light source affected the phenolic and flavonoid contents and antioxidant activity. A simple and reliable HPLC method using a PAH C18 column was applied for the quantitative analysis of two triterpenoids from the S. plebeia groups. Oleanolic acid (OA) and ursolic acid (UA) showed good linearity (R2 > 0.9999) within the test ranges (0.005–0.05 mg/mL), and the average percentage recoveries of the OA and UA were 95.1–104.8% and 97.2–107.1%, respectively. The intra- and inter-day relative standard deviations (RSDs) were less than 2.0%. After exposure to sunlight, the phenolic contents, including rosmarinic acid, showed a reduced tendency, whereas the flavonoid contents, including homoplantaginin and luteolin 7-glucoside, were increased. The content of the triterpenoids also showed an increased tendency under sunlight irradiation, but the variance was not larger than those of the phenolic and flavonoid contents. Among experimental groups, the group harvested at six months, having been exposed to sunlight for two months, showed the most potent antioxidant activity. Therefore, these results showed that the chemical composition and antioxidant activities of S. plebeia R.Br. was affected from environmental culture conditions, such as light source. Our studies will be useful for the development of functional materials using S. plebeia R.Br.

Low temperature and ultraviolet-B radiation affect chlorophyll content and induce the accumulation of UV-B-absorbing and antioxidant compounds in bell pepper (Capsicum annuum) plants

Low temperature (LT) and ultraviolet-B (UV-B) radiation are abiotic factors that cause plant stress and limit crop production because of their detrimental effects on photosynthetic components. There is evidence of chlorophyll and carotenoid degradation by LT and UV-B radiation, as well as the production of phenolic compounds as defense components against these stress factors; however, there is scarce information about the interactions between LT and UV-B radiation. Therefore, in this study, the contents of chlorophyll, carotenoids, and phenolic compounds were analyzed in response to LT, UV-B radiation and the combination of both (LT+UV-B) in leaves of bell pepper plants. The LT+UV-B condition produced the greater degradation of chlorophyll in the bell pepper leaves and the higher accumulation of carotenoids, chlorogenic acid and the flavonoids apigenin-7-O-glucoside (A-7-G) and luteolin-7-O-glucoside (L-7-G) compared to the LT and UV-B conditions applied separately. UV-B radiation induced a higher total flavonoid concentration than LT, but the highest flavonoid concentration was observed in the leaves exposed to LT+UV-B. The higher accumulation of chlorogenic acid and A-7-G biosynthesis in leaves exposed to LT than control, indicate a higher resistance of plants to UV-B radiation damage because chlorogenic acid and A-7-G both have high UV-B absorbance capacities. However, a higher concentration of L-7-G, respect to A-7-G, in leaves exposed to UV-B and LT+UV-B indicates a higher necessity to quench ROS, because L-7-G has a higher antioxidant capacity than A-7-G. The increment of carotenoid and L-7-G concentrations in bell pepper plants exposed to LT and UV-B radiation stress displayed a high correlation with the raise of total reducing capacity in their leaves.

Protective effects of luteolin-7-O-glucoside against starvation-induced injury through upregulation of autophagy in H9c2 Cells.

Cardiomyocyte nutrient deprivation is a common clinical event that mediates various cardiac ischemic processes and is associated with autophagy activation and cell survival or death. Luteolin-7-O-glucoside (LUTG) was one of the flavonoid glycosides isolated from Dracocephalum tanguticum. Previous research had showed that LUTG pretreatment had significant protective effects against doxorubicin-induced cardiotoxicity. However, whether LUTG could protect cardiomyocytes from starvation-induced injury was not clear. In this study, cardioprotection and mechanisms of LUTG against starvation-induced injury were investigated in vitro. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2-tetrazolium bromide (MTT) assay showed starvation-induced autophagy is a homeostatic and protective response for H9c2 cell survival. LUTG could protect against injury induced by starvation in H9c2 cells. Acridine orange (AO) staining showed that pretreatment with LUTG enhanced lysosomal autophagy. Western blotting indicated that LUTG enhanced autophagy by down-regulating the expression of phospho-extracellular signal regulated kinase1/2 (p-ERK), phospho-protein kinase B (p-Akt) and phospho-mammalian target of rapamycin (p-mTOR). These results suggest that LUTG might act as a promising therapeutic agent for preventing starvation-induced cardiotoxicity by upregulation of autophagy through the Akt/mTOR and ERK signal pathway.