Effect of maqui-berry extract in dry eye disease – A clinical and molecular analysis

Purpose: This study aims to investigate the effects of maqui?berry extract (MBE) in improving signs and symptoms of dry eye disease (DED) along with ocular surface inflammation in patients with DED. Methods: Twenty patients were randomly assigned to a MBE or a placebo group (PLC). DED parameters including Schirmer’s test 1 (ST1), tear film break?up time (TBUT), ocular surface disease index (OSDI), and corneal staining were assessed before treatment and 2 months post?treatment. Tear fluid samples before and after treatment from a subset of these patients were collected from the study subjects using sterile Schirmer’s strips, and the levels of interleukin (IL)?1?, IL?10, IL?6, IL?17A, tumor necrosis factor?? (TNF?), matrix metalloproteinase?9 (MMP9), soluble intercellular adhesion molecule?1 (sICAM1), and vascular endothelial growth factor?A (VEGF?A) were measured using a microfluidic cartridge?based multiplex ELISA. Results: The MBE group demonstrated a significant (p < 0.05) decrease in OSDI scores along with a significant increase in Schirmer’s test 1 compared to the PLC group. No significant change in TBUT and corneal staining was observed between the study groups. Levels of proinflammatory factors such as IL?1?, IL?6, IL?17A, TNF?, and MMP9 were observed to be significantly reduced, along with a significant increase in IL?10 levels following treatment in the MBE group compared with the PLC group. Conclusion: Consumption of MBE resulted in the resolution of DED signs and symptoms, along with a reduction in ocular surface inflammation.

Influência da Delfinidina como potencial modulador da capacidade imunorregulatória das Células-Tronco Mesenquimais / Influence of Delphinidin as a potential modulator of the immunoregulatory capacity of Mesenchymal Stem Cells

As Células-Tronco Mesenquimais (CTMs), são células multipotentes, presentes em diversos tecidos, sendo bastante estudada devido sua capacidade imunorregulatória por meio da liberação de fatores solúveis. Fatores estes que atuam sobre as funções de células do sistema imunitário. Simultaneamente, estudos indicam que os compostos flavonoides, em destaque a Delfinidina, presente em alguns frutos e flores, possuem atuação anti-inflamatória e inibitória sobre células do sistema imunitário. Todavia, são escassos os estudos em relação entre a capacidade imunorregulatória da CTM e a influência da Delfinidina, sendo este o objetivo deste estudo. Inicialmente, a Delfinidina 3-O-ß-D-glicosídeo foi escolhido, devido a sua maior estabilidade e a dose de 50 µM foi selecionada após análise por citometria de fluxo que mostrou aumento da fase proliferativa do ciclo celular. Posteriormente ao realizar análise da produção de fatores solúveis pelas CTM, os resultados mostraram aumento da produção de IL-10, TGF-ß e Oxido nítrico pelas CTM tratadas com Delfinidina. Bem como, diminuição da expressão de p-NF-κB/NF-κB pelas CTMs tratadas com Delfinidina, quando avaliadas por Wersten Blot. Adicionalmente, para analisar a Delfinidina sobre os efeitos imunorregulatórios da CTM sob macrófagos (RAW 264.7), célula esta, importante no sistema imune inato. Foram realizadas culturas condicionadas, com posterior análise da produção de fatores solúveis, os resultados mostraram aumento da produção de IL-10, e diminuição da produção de TNF-α, IL-1α e IL-12 pelos macrófagos, nas culturas condicionadas. Assim como, diminuição da expressão do fator p-NF-κB/NF-κB pelos macrófagos nas culturas condicionadas, quando avaliadas por Wersten Blot. Ademais, ao analisar a atividade metabólica dos macrófagos por ensaio de MTT, os resultados mostraram que as culturas condicionadas e a Delfinidina per si foi capaz de diminuir a atividade metabólica, sem alterar os efeitos anti-inflamatórios sobre a célula. Em síntese, a Delfinidina mostrou acentuar a atuação imunorregulatória da CTM sobre a linhagem macrofágica, célula esta, de grande importância para o sistema imune inato

Mesenchymal Stem Cells (MSCs) are multipotent cells present in various tissues, being widely studied due to their immunoregulatory capacity through the release of soluble factors. These factors act on the functions of cells of the immune system. Simultaneously, studies indicate that flavonoid compounds, especially Delphinidin, present in some fruits and flowers, have anti inflammatory and inhibitory effects on immune system cells. However, there are few studies on the relationship between the immunoregulatory capacity of MSC and the influence of Delphinidin, which is the objective of this study. Initially, Delphinidin 3-O-ß-D-glycoside was chosen due to its greater stability and the 50 µM dose was selected after analysis by flow cytometry which showed an increase in the proliferative phase of the cell cycle. Subsequently, when analyzing the production of soluble factors by MSCs, the results showed an increase in the production of IL-10, TGF-ß and nitric oxide by MSCs treated with Delphinidin. As well as decreased expression of p-NF-κB/NF-κB by MSCs treated with Delphinidin, when evaluated by Wersten Blot. Additionally, to analyze Delphinidin on the immunoregulatory effects of MSC on macrophages (RAW 264.7), this cell is important in the innate immune system. Conditioned cultures were performed, with subsequent analysis of the production of soluble factors, the results showed an increase in the production of IL-10, and a decrease in the production of TNF-α, IL-1α and IL-12 by macrophages, in the conditioned cultures. As well as decreased expression of p-NF-κB/NF-κB factor by macrophages in conditioned cultures, when evaluated by Wersten Blot. Furthermore, when analyzing the metabolic activity of macrophages by MTT assay, the results showed that conditioned cultures and Delphinidin itself was able to decrease the metabolic activity, without altering the anti-inflammatory effects on the cell. In summary, Delphinidin has shown to enhance the immunoregulatory action of MSC on the macrophage lineage, a cell that is of great importance for the innate immune system

Protect effect of Delphinidin on light induced oxidative damage of retina / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the mechanism of Delphinidin(Dp)in protecting retinal against light induced oxidative damage.<p>METHODS: All 661W photosensitive cells were treated with 2 000Lx light(48h)and/or different concentrations of Dp(5, 10, 20μmol/L, 24h). Cell activity, intracellular LDH activity, TBARS content and antioxidant enzymes(SOD, GSH-Px, GST)activity were determined respectively. After the healthy SD rats were treated with 3 000 Lx light(24h)and/or Dp \〖100mg/(kg·d)for 4wk\〗, then changes in retinal tissue structure were observed and fluctuations in oxidative stress index(SOD, GSH-Px, GST)were determined.<p>RESULTS: The results of <i>in vitro</i> experiments showed that the cell activity was significantly decreased after irradiation, the LDH activity and TBARS content were increased, and the activity of antioxidant enzyme system were decreased. However, Dp treatment could increase cell viability, decrease LDH activity and TBARS content, and increase the activity of antioxidant enzyme system. <i>In vivo</i> experiments showed that Dp can protect the structural integrity of retina, reduce the content of TBARS in retinal tissue, and increase the activity of SOD, GSH-Px and GST.<p>CONCLUSION: Dp may protect retinal against Photochemical factors -induced oxidative damage by regulating the oxidation-antioxidant system.

Solanum melongena (Eggplant) Crude Anthocyanin Extract and Delphinidin-3- glucoside protects Caenorhabditis elegans against Staphylococcus aureus and Klebsiella pneumoniae

Background and Objectives@#During infection, Reactive oxygen species (ROS) signaling is activated to protect the cells from invading microorganisms. However, a high level of ROS may also damage the host tissue. The anthocyanin delphinidin is known to have a strong antioxidant activity that protects cells from oxidative damage. This study explored the potential of crude anthocyanin extract from the fruit of Solanum melongena (Eggplant) and Delphinidin-3-glucoside in enhancing the innate immunity in Caenorhabditis elegans against Staphylococcus aureus and Klebsiella pneumoniae.@*Methodology@#Caenorhabditis elegans was used to study innate immune response because it lacks adaptive immunity. First, the sublethal concentration of S. melongena crude anthocyanin extract (SMCAE) and Delphinidin-3-glucoside (D3G) in C. elegans was determined. The sublethal concentration of SMCAE and D3G was used to supplement the nematodes during its exposure to S. aureus and K. pneumoniae. The survival rate was then observed until day five post-L4. SMCAE and D3G were also tested for probable antimicrobial activity against Staphylococcus aureus and Klebsiella pneumoniae. @*Results and Conclusion@#This study found that both SMCAE and D3G showed no inhibitory effect on the growth of the bacteria. However, both SMCAE and D3G enhanced the survival of the nematode when exposed to S. aureus and K. pneumoniae. Overall, this study indicates that the anthocyanin delphinidin in S. melongenacrude extract protected the C. elegans against S. aureus and K. pneumoniaeinfection through its antioxidant activity.

The inhibitory effect and molecular mechanism of delphindin on HER-2 positive breast cancer / 天津医药

@#Objective To investigate the inhibitory effect and molecular mechanism of delphinidin (Dp) on HER-2 positive breast cancer. Methods The HER-2 positive breast cancer cells (MDA-MB-453 and BT-474) were treated with different concentrations of delphinidin (10，20，40，80 and 160 μmol/L) for 48 hours. The same concentration of DMSO was used as the solvent control. CCK-8 method was used to measure the effect of Dp on cell activity, and half maximal inhibitory concentration (IC50) was calculated to determine the concentration of subsequent experiments. The cells were treated with different concentrations of Dp (20, 40 and 80 μmol/L) for 48 hours. HE staining was used to observe the cell morphological changes. Flow cytometry was used to analyze the cell cycle. Cell apoptosis rate was detected by TUNEL assay. The phosphorylation levels of NF - κB signaling pathway related proteins were determined by Western blot assay. Results Delphinidin inhibited the proliferation of MDA-MB-453 and BT-474 in the concentration ranges of 10，20，40，80 and 160 μmol/L (IC50: 41.02 and 60.97 μmol/L). In the concentrations of 20，40 and 80 μmol/L, compared with the control group, it was found that some cells were detached, floated and lysed, and the cell volume was decreased, the proportion of cells in G2/ M phase and the apoptosis rate were increased in DP treatment groups. Compared with the control group, the expression levels of p-NF-κB/p65, p-IκBα, p-IKKα/β and p-PKCα were significantly decreased in the 40 and 80 μmol/L Dp treatment groups, while the expression levels of IκBα, IKKα, IKKβ and PKCα were increased in the Dp treatment groups (P＜0.05). Conclusion Delphinine can inhibit the proliferation of breast cancer cells by blocking the NF-κB signaling pathway and inducing the G2/M cycle arrest and apoptosis of MDA-MB-453 and BT-474 cells. Key words：receptor, epidermal growth factor; antineoplastic agents, phytogenic; breast neoplasms; cell cycle; delphinidin;HER-2 positive breast cancer; NF-κB signaling pathway

Radioprotective effects of delphinidin on normal human lung cells against proton beam exposure

BACKGROUND/OBJECTIVES: Exposure of the normal lung tissue around the cancerous tumor during radiotherapy causes serious side effects such as pneumonitis and pulmonary fibrosis. Radioprotectors used during cancer radiotherapy could protect the patient from side effects induced by radiation injury of the normal tissue. Delphinidin has strong antioxidant properties, and it works as the driving force of a radioprotective effect by scavenging radiation-induced reactive oxygen species (ROS). However, no studies have been conducted on the radioprotective effect of delphinidin against high linear energy transfer radiation. Therefore, this study was undertaken to evaluate the radioprotective effects of delphinidin on human lung cells against a proton beam. MATERIALS/METHODS: Normal human lung cells (HEL 299 cells) were used for in vitro experiments. The 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay assessed the cytotoxicity of delphinidin and cell viability. The expression of radiation induced cellular ROS was measured by the 2′-7′-dicholordihydrofluorescein diacetate assay. Superoxide dismutase activity assay and catalase activity assay were used for evaluating the activity of corresponding enzymes. In addition, radioprotective effects on DNA damage-induced cellular apoptosis were evaluated by Western blot assay. RESULTS: Experimental analysis, including cell survival assay, MTT assay, and Western blot assay, revealed the radioprotective effects of delphinidin. These include restoring the activities of antioxidant enzymes of damaged cells, increase in the levels of pro-survival protein, and decrease of pro-apoptosis proteins. The results from different experiments were compatible with each to provide a substantial conclusion. CONCLUSION: Low concentration (2.5 µM/mL) of delphinidin administration prior to radiation exposure was radioprotective against a low dose of proton beam exposure. Hence, delphinidin is a promising shielding agent against radiation, protecting the normal tissues around a cancerous tumor, which are unintentionally exposed to low doses of radiation during proton therapy.

Delphinidin induces autophagy in HER-2+ breast cancer cells via inhibition of AKT/mTOR pathway / 中南大学学报(医学版)

Objective:To explore the effect of delphinidin on breast cancer and the underlying mechanisms.Methods:Human epidermal growth factor receptor-2 (HER-2) positive breast cancer cells MDA-MB-453 were treated by delphinidin.Proliferation of MDA-MB-453 cells was detected by CCK-8 after 48 h.TdT-mediated dUTP nick end labeling (TUNEL) assay and Western blot were used to explore apoptotic status for MDA-MB-453 cells.Fluorescence dot assay,immunofluorescence,and Western blot were used to identify autophagy in breast cancer cells.Results:Delphinidin suppressed proliferation of MDA-MB-453 cells.Delphinidin increased the number of TUNEL positive cells.Delphinidin downregulated the expression of caspase-3 and caspase-9,while upregulated the expression of cleaved caspase-3 and cleaved caspase-9 in a dose-dependent manner.Delphinidin enhanced the number of GFP-LC3 punctate dots,LC3 immunofluorescence dots and the expression of LC3-Ⅱ and ATG5.Delphinidin inhibited the expression of proteins in mTOR signaling pathway,induding AKT,mTOR,eIF4E and p70s6k.Conclusion:Delphinidin induced apoptosis and autophagy by inhibition of AKT/mTOR pathway in HER positive breast cancer cells.

Cytoprotective Mechanism of Cyanidin and Delphinidin against Oxidative Stress-Induced Tenofibroblast Death

Age-related rotator cuff tendon degeneration is related to tenofibroblast apoptosis. Anthocyanins reduce oxidative stress-induced apoptotic cell death in tenofibroblasts. The current study investigated the presence of cell protective effects in cyanidin and delphinidin, the most common aglycon forms of anthocyanins. We determined whether these anthocyanidins have antiapoptotic and antinecrotic effects in tenofibroblasts exposed to H₂O₂, and evaluated their biomolecular mechanisms. Both cyanidin and delphinidin inhibited H₂O₂-induced apoptosis in a dose-dependent manner. However, at concentrations of 100 μg/ml or greater, delphinidin showed cytotoxicity against tenofibroblasts and a decreased antinecrotic effect. Cyanidin and delphinidin both showed inhibitory effects on the H₂O₂-induced increase in intracellular ROS formation and the activation of ERK1/2 and JNK. In conclusion, both cyanidin and delphinidin have cytoprotective effects on cultured tenofibroblasts exposed to H₂O₂. These results suggest that cyanidin and delphinidin are both beneficial for the treatment of oxidative stress-mediated tenofibroblast cell death, but their working concentrations are different.

Suppression of β-catenin Signaling Pathway in Human Prostate Cancer PC3 Cells by Delphinidin

Delphinidin possesses strong anti-oxidant, anti-inflammatory, and anti-cancer properties. Suppression of the Wnt/β-catenin signaling pathway is a potential strategy for chemoprevention and therapy. As aberrant activation of the β-catenin signaling pathway contributes to prostate cancer progression, we evaluated the effect of delphinidin on this pathway in human PC3 prostate cancer cells. An MTT assay showed that treatment with delphinidin (15-180 μM, 72 hours) resulted in a dose-dependent growth inhibition of cells. Treatment with delphinidin increased the phosphorylation of serine or threonine residues on β-catenin and decreased the levels of cytoplasmic β-catenin. Moreover, treatment with delphinidin inhibited the nuclear translocation of β-catenin and the expression of β-catenin target genes such as cyclin D1, c-myc, Axin-2, and T cell factor-1. Delphinidin also induced the phosphorylation of glycogen synthase kinase 3β and the expression of adenomatous polyposis coli and Axin proteins. Our results indicate that inhibition of cell growth by delphinidin is mediated, at least in part, through modulation of the β-catenin signaling pathway. We suggest that delphinidin is a potent inhibitor of Wnt/β-catenin signaling in prostate cancer cells.

Inhibitory Effect of Delphinidin on Extracellular Matrix Production via the MAPK/NF-kappaB Pathway in Nasal Polyp-Derived Fibroblasts

PURPOSE: Nasal polyps are associated with chronic inflammation of the mucous membranes in the nose and paranasal sinuses and involved in extracellular matrix (ECM) accumulation. Delphinidin promotes ECM degradation in hepatitis and cardiac fibrosis. The aims of this study were to examine the inhibitory effect of delphinidin on TGF-beta1-induced myofibroblast differentiation and ECM accumulation, and to determine the underlying mechanisms in nasal polyp-derived fibroblasts (NPDFs). METHODS: NPDFs were stimulated with TGF-beta1, with or without delphinidin, and the expression levels of alpha-SMA, fibronectin, and collagen type I were determined by RT-PCR, Western blot analysis, and collagen assay. The expression of alpha-SMA protein was measured by immunocytochemical staining. Mitogen-activated protein kinase and NF-kappaB activation induced by TGF-beta1 were determined by Western blot analysis. The transcriptional activity of NF-kappaB was measured by luciferase assay. RESULTS: The expression levels of alpha-SMA, fibronectin, and collagen type I increased in TGF-beta1-stimulated NPDFs. In TGF-beta1-induced NPDFs, delphinidin inhibited the expression of alpha-SMA, fibronectin, and collagen. Inhibitors of MAPK and NF-kappaB blocked the expression of alpha-SMA, fibronectin, and collagen type I. Delphinidin suppressed the activation of MAPK and NF-kappaB induced by TGF-beta1 stimulation. CONCLUSIONS: These results suggest that delphinidin may inhibit TGF-beta1-induced myofibroblast differentiation and ECM production through the MAPK/NF-kappaB signaling pathway in NPDFs.

Delphinidin Inhibits LPS-Induced MUC8 and MUC5B Expression Through Toll-like Receptor 4-Mediated ERK1/2 and p38 MAPK in Human Airway Epithelial Cells

OBJECTIVES: Delphinidin is one of the anthocyanidins. It is believed to have anti-inflammatory property including antioxidant, antiangiogenic, and anti-cancer properties. However, the anti-inflammatory effect of delphinidin in mucin-producing human airway epithelial cells has not been determined. Therefore, this study was conducted in order to investigate the effect and the brief signaling pathway of delphinidin in lipopolysaccharide (LPS)-induced MUC8 and MUC5B expression in human airway epithelial cells. METHODS: In mucin-producing human NCI-H292 airway epithelial cells and primary cultures of normal nasal epithelial cells, the reverse transcriptase-polymerase chain reaction (RT-PCR), real-time PCR, enzyme immunoassay were used for investigating the expressions of MUC8, MUC5, and Toll-like receptor 4 (TLR4), after LPS treatment and delphinidin treatment. And the signaling pathway of delphinidin on LPS-induced MUC8 and MUC5B expression was investigated using the RT-PCR, and immunoblot analysis. To confirm the involvement of TLR4 in LPS-induced MUC8 and MU5B expression, the cells were transfected with TLR4 siRNA. RESULTS: In NCI-H292 airway epithelial cells, LPS (100 ng/mL) significantly induced TLR4, MUC8, and MUC5B expression. TLR4 siRNA significantly blocked LPS-induced MUC8 and MUC5B mRNA expression. LPS (100 ng/mL) significantly activated the phosphorylation of extracellular signal related kinase (ERK) 1/2 and p38 mitogen-activated protein kinase (MAPK). Delphinidin (50 and 100 microM) inhibited LPS-induced TLR4, MUC8, and MUC5B expression and LPS-induced phosphorylation of ERK1/2 and p38 MAPK. In the primary cultures of normal nasal epithelial cells, delphinidin (50 and 100 microM) significantly inhibited LPS-induced TLR4, MUC8, and MUC5B gene expression. CONCLUSION: These results suggest that delphinidin attenuates LPS-induced MUC8 and MUC5B expression through the TLR4-mediated ERK1/2 and p38 MAPK signaling pathway in human airway epithelial cells. These findings indicated that delphinidin may be a therapeutic agent for control of inflammatory airway diseases.

Effect of Anthocyanidin on MUC5AC and MUC5B Expression in Airway Epithelial Cells / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Naringenin and delphinidin are types of anthocyanidin, which are flavonoids and thus have anti-inflammatory property. Moderate consumption of natural dietary naringenin and delphinidin is believed to do anti-inflammatory action, but the action mechanism is unclear. Therefore, this study aimed to investigate the effects of naringenin and delphinidin on interleukin-1beta (IL-1beta)- and lipopolysaccharide (LPS)-induced MUC5AC and MUC5B expressions in airway epithelial cells. MATERIALS AND METHOD: In NCI-H292 cells and cultured nasal polyp epithelial cells, the effects of naringenin and delphinidin on IL-1beta- and LPS-induced MUC5AC and MUC5B expressions were analyzed by real-time polymerase chain reaction and enzyme-linked immunosorbent assay. RESULTS: Delphinidin attenuated IL-1beta- and LPS-induced MUC5AC and MUC5B mRNA and glycoprotein expression in a dose-dependent pattern in NCI-H292 cells and in cultured nasal polyp epithelial cells. Naringenin partially attenuated IL-1beta- and LPS-induced MUC5AC and MUC5B mRNA and glycoprotein expression at a high dose. CONCLUSION: These results suggest that delphinidin attenuates MUC5AC and MUC5B expressions in the airway epithelial cells. Between anthocyanidin and delphinidin, delphinidin exhibits greater potential as an ideal therapeutic agent for the control of mucus-hypersecretion in the treatment of airway inflammatory diseases.

Delphinidin inhibits cell proliferation and induces apoptosis in MDA-MB-231 human breast cancer cell lines / 한국영양학회지

Breast cancer is the most common malignancy in women, both in the developed and developing countries. Anthocyanins are natural coloring of a multitude of foods, such as berries, grapes or cherries. Glycosides of the aglycons delphinidin represent the most abundant anthocyanins in fruits. Delphinidin has recently been reported to inhibit the growth of human tumor cell line. Also, delphinidin is a powerful antioxidant that reportedly exerts beneficial effects in patients with advanced cancer by reducing the level of reactive oxygen species and increasing glutathion peroxidase activity. This study investigates the effects of delphinidin on protein ErbB2, ErbB3 and Akt expressions associated with cell proliferation and Bcl-2, Bax protein associated with cell apoptosis in MDA-MB-231 human breast cancer cell line. MDA-MB-231 cells were cultured with various concentrations (0, 5, 10, and 20 micromol/L) of delphinidin. Delphinidin inhibited breast cancer cell growth in a dose dependent manner (p < 0.05). ErbB2 and ErbB3 expressions were markdly lower 5 micromol/L delphinidin (p < 0.05). In addition, total Akt and phosphorylated Akt levels were decreased dose-dependently in cells treated with delphinidin (p < 0.05). Futher, Bcl-2 levels were dose-dependently decreased and Bax expression was significantly increased in cells treated with delphinidin (p < 0.05). In conclusion, I have shown that delphinidin inhibits cell growth, proliferation and induces apoptosis in MDA-MB-231 human breast cancer cell lines.

Significance of p27(kip1) as potential biomarker for intracellular oxidative status

Our previous proteomic study demonstrated that oxidative stress and antioxidant delphinidin regulated the cellular level of p27(kip1) (referred to as p27) as well as some heat shock proteins in human colon cancer HT 29 cells. Current study was conducted to validate and confirm the regulation of these proteins using both in vitro and in vivo systems. The level of p27 was decreased by hydrogen peroxide in a dose-dependent manner in human colon carcinoma HCT 116 (p53-positive) cells while it was increased upon exposure to hydrogen peroxide in HT 29 (p53-negative) cells. However, high concentration of hydrogen peroxide (100 micrometer) downregulated p27 in both cell lines, but delphindin, one of antioxidative anthocyanins, enhanced the level of p27 suppressed by 100 micrometer hydrogen peroxide. ICR mice were injected with varying concentrations of hydrogen peroxide, delphinidin and both. Western blot analysis for the mouse large intestinal tissue showed that the expression of p27 was upregulated by 25 mg/kg BW hydrogen peroxide. To investigate the association of p27 regulation with hypoxia-inducible factor 1-beta (HIF-1beta), the level of p27 was analyzed in wild-type mouse hepatoma hepa1c1c7 and Aryl Hydrocarbon Nuclear Translocator (arnt, HIF-1beta)-defective mutant BPRc1 cells in the absence and presence of hydrogen peroxide and delphinidin. While the level of p27 was responsive to hydrogen peroxide and delphinidin, it remained unchanged in BPRc1, suggesting that the regulation of p27 requires functional HIF-1beta. We also found that hydrogen peroxide and delphinidin affected PI3K/Akt/mTOR signaling pathway which is one of upstream regulators of HIFs. In conclusion, hydrogen peroxide and antioxidant delphinidin seem to regulate intracellular level of p27 through regulating HIF-1 level which is, in turn, governed by its upstream regulators comprising of PI3K/Akt/mTOR signaling pathway. The results should also encourage further study for the potential of p27 as a biomarker for intracellular oxidative or antioxidant status.