Effects Of Oroxylin Research Articles

Oroxylin A inhibits inflammatory cytokines in periodontitis via HO‑1.

Periodontal disease is a common infectious disease that can lead to the loss of teeth. Hower how to effectively suppress the inflammation with medication is unclear. The aim of the present study was to investigate the anti‑inflammatory effect of Oroxylin A in periodontitis and its potential role through heme oxygenase‑1 (HO‑1). Primary rat gingival fibroblasts (RGFs) were cultured using the tissue block method and identified by immunofluorescence. Following lipopolysaccharide (LPS) stimulation of RGFs, Oroxylin A was administered at 50, 100, 200 or 400 µg/ml. Reverse transcription‑quantitative PCR was used to assess mRNA expression of cyclooxygenase (COX)‑2, TNF‑α, RANKL and osteoprotegerin (OPG). Western blotting was used to detect protein expression levels of COX ‑2, TNF‑α, RANKL and OPG. Following HO‑1 knockdown, the same treatment was performed. The expression of COX‑2 in rat gingival tissue was observed by immunohistochemistry. One‑way analysis of variance and Student's t test were used for statistical analysis. Oroxylin A downregulated mRNA expression of COX‑2, TNF‑α, RANKL and OPG in LPS‑induced RGFs. With increase of Oroxylin A dose, the expression of HO‑1 was gradually upregulated. When HO‑1 was knocked down, Oroxylin A did not downregulate the expression of COX‑2, TNF‑α, RANKL and OPG in LPS‑induced RGFs. Immunohistochemical results showed that expression of COX‑2 was downregulated by Oroxylin A, and the expression of TNF‑α, RANKL and OPG were also downregulated. Oroxylin A decreased expression of inflammatory cytokines in LPS‑induced RGFs and had a good inhibitory effect on periodontitis in rats.

Oroxylin A attenuates cytokines in neonatal asthmatic mice by regulating Notch signaling pathway


 
 
 
 Purpose: To investigate the protective effect of oroxylin A against neonatal asthma in mice.
 Methods: Asthma was induced in P12 mice with ovalbumin (OVA) immediately after litter (day 0), and on day 14 of protocol. Oroxylin A was given daily in two doses (2 and 10 mg/kg, i.p.) from day 0 to 14, 2 h before the administration of OVA. The protective effect of oroxylin A against asthma was determined by evaluating lung function and levels of cytokines and IgE in OVA-challenged mice. Moreover, Western blot assay and quantitative real-time polymerase chain reaction (qRT-PCR) were used to determine the effect of oroxylin A on Notch signaling pathway in OVA-challenged mice.
 Results: Oroxylin A improved lung function in OVA-challenged mice. There were significant (p < 0.01) reductions in levels of IgE and cytokines in the BALF of oroxylin A-treated group, when compared to OVA group of mice. Furthermore, treatment with oroxylin A significantly ameliorated the OVA-induced changes in protein expressions of Notch1, Jagged1, NICD, PTEN, PI3K and Akt in the CD+ cells of OVA-challenged mice (p < 0.01).
 Conclusion: These results indicate that oroxylin A improves lung function and reduces the level of cytokines in neonatal asthmatic rat by downregulating Notch signaling. Thus, oroxylin A may be clinically beneficial in the management of asthma.
 
 
 

Oroxylin A Shows Protective Effects on Biological Activity of Lipopolysaccharide Treated Human Periodontal Ligament Stem Cells

The abnormal proliferation and apoptosis of human periodontal ligament stem cells (hPDLSCs) serves a crucial role in the development of periodontitis. Oroxylin A has shown protective effects in a variety of inflammatory diseases. The present study was aimed to investigate the effects of oroxylin A on lipopolysaccharide (LPS) treated hPDLSCs. In the present study, cells were exposed to different concentrations (10, 20, 40 uM) of oroxylin A for 24 h or 48 h, co-treated with LPS. The cell proliferation capacity was assessed using cell counting kit-8 (CCK-8), and the cell apoptosis was evaluated by flow cytometry. The Ki67 expression was measured using immunofluorescence and NO production was detected by enzyme linked immunosorbent assay (ELISA) respectively. Western blot analyses were used to investigate the level of cell proliferation related proteins (PCNA, CDK2 and p21) as well as NF-κB, I-κBα and downstream molecules iNOS, IL-6 and TNF-α. The results demonstrated that oroxylin A increased cell survival of LPS treated hPDLSCs in a dose-dependent and time-dependent manner. In addition, oroxylin A treatment inhibited cell apoptosis in hPDLSCs. Furthermore, the levels of NO, NF-κB, iNOS, IL-6 and TNF-α were significantly reduced. And the expression of Ki67, I-κBα, PCNA and CDK2 were significantly increased. Taken together, these findings indicate that oroxylin A promote proliferation and suppress apoptosis in a dose-dependent and time-dependent manner. Oroxylin A may affects LPS induced biological activity via inhibiting NF-κB activation and proinflammatory cytokines expression in hPDLSCs.

Abstract 896: Long term exposure to Oroxylin A inhibits cell migration via suppressing CCL2 in oral squamous cell carcinoma cells

Abstract Oral squamous cell carcinoma (OSCC) is the sixth most common cancer in the world. Like other cancers, the major causes of OSCC-related death are cervical node and distant metastasis. Therefore, it is a critical need to identify new potential therapeutic agents against OSCC migration, invasion, and metastasis. Oroxylin A, a main bioactive flavonoids extracted from Scutellaria radix, has been reported to inhibit migration in breast and non-small-cell lung cancer. In this study, we explored the anti-migration effects of oroxylin A on OSCC cells and investigated its underlying mechanisms. A 24-hour exposure (short-term) of OSCC cells to oroxylin A at noncytotoxic concentrations (5-20 μM) significantly suppressed cell migration using the wound healing assay. Furthermore, a 30-days exposure (long-term) to oroxylin A (20 μM), which still had no cytotoxic effect on OSCC cells, but significantly suppressed more cell migration than that of short-term oroxylin A exposed OSCC cells. To uncover the molecular mechanisms involved in the inhibitory effect of oroxylin A on OSCC migration, cDNA microarray technique and Ingenuity software were used. There were 468 differentially expressed genes, including 112 upregulated and 356 downregulated genes identified in long-term oroxylin A exposed cells compared to untreated OSCC cells. Among them, 77 genes have been reported to be associated with cancer cell migration. Consistent with results from cDNA microarray, we revealed that the expressions of several cell migration-related genes, such as CCL2, S100A9, LCN2, and THBS1 were significantly decreased in long-term oroxylin A exposed OSCC cells using QPCR assay. Western blotting and ELISA results also demonstrated that CCL2 expressions at mRNA and protein levels were significantly decreased in long-term oroxylin A exposed OSCC cells compared to untreated OSCC cells. In the meantime, the expressions of downstream targets of CCL2, including p-ERK, NFκB, MMP2, and MMP9 were also decreased in long-term oroxylin A exposed OSCC cells. These results suggest that long-term oroxylin A treatment inhibits migration may via suppressing CCL2 in OSCC cells. Citation Format: Jiun-Jia Tung, Tony Jer-Fu Lee, Wei-Ting Ku, Kuo-Chu Lai. Long term exposure to Oroxylin A inhibits cell migration via suppressing CCL2 in oral squamous cell carcinoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 896. doi:10.1158/1538-7445.AM2017-896

Oroxylin A attenuates cigarette smoke-induced lung inflammation by activating Nrf2

Oroxylin A, a natural flavonoid isolated from the medicinal herb Scutellaria baicalensis Georgi, has been reported to have anti-inflammatory and antioxidant properties. However, the effect of oroxylin A on cigarette smoke (CS)-induced lung inflammation remains unclear. In this study, the ability of oroxylin A to protect against CS-induced lung inflammation was detected in vivo and in vitro. Oroxylin A was administered intraperitoneally to mice 2h prior CS exposure every day for five consecutive days. BEAS-2B bronchial epithelial cells and RAW264.7 cells were used to investigate the molecular mechanism of oroxylin A in vitro. In vivo, the results showed that oroxylin A dose-dependently attenuated CS-induced lung histopathologic changes, expression of cytokines TNF-α, IL-1β, and MCP-1, and levels of oxidative biomarkers 3-nitrotyrosine and 8-isoprostane. Meanwhile, oroxylin A up-regulated GSH level and glutathione reductase (GR) activity in lung tissues. In vitro, oroxylin A significantly up-regulated Nrf2 expression and total cellular glutathione level in cigarette smoke extract (CSE)-stimulated cells. In addition, oroxylin A promoted Nrf2 binding to antioxidant response element (ARE) and up-regulated ARE-regulated gene such as heme oxygenase-1 (HO-1), GPx, and GR in CSE-stimulated cells. Oroxylin A could protect both epithelial cells and macrophages from damage by cigarette smoke in vitro. Taken together, these data indicated that oroxylin A attenuated oxidative stress and lung inflammation induced by CS via activating Nrf2 signaling pathway. Oroxylin A may be a protective agent against CS-induced lung inflammation and chronic obstructive pulmonary disease.

Effect of Oroxylin A on Hydrogen Peroxide Production in Polyinosinic-Polycytidylic acid-induced TM4 Mouse Testis Sertoli Cells

The purpose of this study is to investigate the modulatory effect of oroxylin A on hydrogen peroxide production in TM4 mouse testis sertoli cells induced by the synthetic analog of double-stranded RNA [polyinosinic-polycytidylic acid]. Hydrogen peroxide production was measured by dihydrorhodamine 123 (DHR) assay. Oroxylin A significantly inhibited the polyinosinic-polycytidylic acid (PIC)-induced production of hydrogen peroxide for 0.5, 2, 12, 18, and 24 hr incubation at the concentrations of 5, 10, 25, and 50 μM in TM4 (P < 0.05) in dose dependent manner. These results suggest that oroxylin A has a protective effect against PIC-induced cellular toxicity with its inhibition of hydrogen peroxide production in PIC-induced sertoli cells. 

Oroxylin A Inhibits Colitis-associated Carcinogenesis Through Modulating the IL-6/STAT3 Signaling Pathway

Patients with inflammatory bowel disease, which includes ulcerative colitis and Crohn's disease, are at a significantly increased risk of developing colorectal cancer, and aberrant interleukin (IL)-6/STAT3 signaling pathway exists in both inflammatory bowel disease and inflammation-related gastrointestinal cancers. We have previously found that oroxylin A inhibited the NF-κB signaling in human colon tumor HCT-116 cells. However, whether oroxylin A could inhibit the colitis-associated carcinogenesis remains to be determined. HCT-116 cells were treated with various concentrations of oroxylin A. Expression of relative proteins of IL-6/STAT3 signaling pathway was assayed by Western blot and immunofluorescence analysis. Mouse model for colitis-associated colorectal cancer was induced by a combined treatment with 10 mg/kg azoxymethane (AOM) followed by 3 cycles of 2.5% dextran sodium sulfate in C57BL/6 mice. IL-6 and IL-1β gene expression were analyzed by quantitative real-time PCR. Expression of relative proteins was examined by immunohistochemistry and Western blot. Oroxylin A effectively inhibited IL-6/STAT3 pathway in human HCT-116 cells, and the effect of oroxylin A was reversible. Dietary administration of oroxylin A throughout the experimental period significantly reduced the tumor burden, inhibited cell proliferation, and induced apoptosis in colon carcinomas. The expression of inflammatory cytokines IL-6 and IL-1β decreased in tumors in oroxylin A-treated mice. The IL-6/STAT3 signaling pathway was attenuated in oroxylin A-treated mice. Our results demonstrated that oroxylin A inhibits colitis-associated carcinogenesis through modulating IL-6/STAT3 pathway in AOM/dextran sodium sulfate mouse model and in HCT-116 cells.

Oroxylin A improves attention deficit hyperactivity disorder-like behaviors in the spontaneously hypertensive rat and inhibits reuptake of dopamine in vitro

In previous studies we have demonstrated that the γ-aminobutryic acid-A (GABA-A) receptor antagonist oroxylin A has an awakening effect and it also represses ADHD-like behaviors (hyperactivity, impulsivity and inattention) in the spontaneously hypertensive rat (SHR) model of attention-deficit hyperactivity disorder (ADHD). We hypothesized that the effects of oroxylin A were exerted via the GABA-A receptor given the important role of the GABAergic system in ADHD. However, it is possible that aside from the GABAergic system, oroxylin A may influence other systems especially those implicated in ADHD (e.g. DAergic, etc.). To test this hypothesis, we evaluated the effects of GABA agonist, or dopamine (DA) antagonist in oroxylin A-induced alleviation of ADHD-like behaviors in SHR. SHR showed inattention and impulsivity as measured by the Y-maze and the electro-foot shock aversive water drinking tests, respectively. Oroxylin A significantly improved these behaviors, furthermore, its effect on SHR impulsivity was attenuated by haloperidol, a DA antagonist, but not by baicalein, an agonist of the GABA-A receptor. In vitro studies showed that oroxylin A inhibited DA uptake similar to methylphenidate, a dopamine transporter blocker, but did not influence norepinephrine uptake unlike atomoxetine, a selective NE reuptake inhibitor. Collectively, the present findings suggest that oroxylin A improves ADHD-like behaviors in SHR via enhancement of DA neurotransmission and not modulation of GABA pathway as previously reported. Importantly, the present study indicates the potential therapeutic value of oroxylin A in the treatment of ADHD.

The Scutellaria Flavone, Oroxylin A, Improves Attention-Deficit/Hyperactivity Disorder Related Behaviors in Spontaneously Hypertensive Rats

Oroxylin A is a flavonoid isolated from Scutellaria baicalensis, which is one of the most important medicinal herbs in traditional Korean medicine. In this study, we investigated the psychopharmacological activities of oroxylin A using the open field, rota-rod, balanced wire and plus-maze tests in Spontaneously Hypertensive Rats (SHR) and Wistar Kyoto Rats (WKY). Oroxylin A reduced hyperactivity in SHR (ADHD animal model) although it tended to increase locomotor activity in WKY. Methylphenidate did not reduce hyperactivity. Oroxylin A alleviated impulsive behaviors such as rearing, the percentage of moving time to the central area and the tendency to move into an unstable condition (open area in elevated plus-maze). Methylphenidate also reduced the percentage of staying time in the central area and the tendency to move into an unstable condition. Both oroxylin A and methylphenidate enhanced motor attention in SHR and WKY. Oroxylin A antagonized the muscimol (<TEX>$GABA_A$</TEX> receptor agonist)-induced <TEX>$Cl^-$</TEX>current and its action was similar to that of bicuculline (<TEX>$GABA_A$</TEX> receptor antagonist). The effects of oroxylin A may be caused by the antagonism at the <TEX>$GABA_A$</TEX> receptor. Thus, oroxylin A may be a candidate of drug for treatment of ADHD.

Oroxylin A induced apoptosis of human hepatocellular carcinoma cell line HepG2 was involved in its antitumor activity

We previously reported that wogonin, a flavonoid compound, was a potent apoptosis inducer of human hepatoma SMMC-7721 cells and murine sarcoma S180 cells. In the present study, the effect of oroxylin A, one wogonin structurally related flavonoid isolated from Scutellariae radix, on human hepatocellular carcinoma cell line HepG2 was examined and molecular mechanisms were also investigated. Oroxylin A inhibited HepG2 cell proliferation in a concentration- and time-dependent manner measured by MTT-assay. Treatment with an apoptosis-inducing concentration of oroxylin A caused typical morphological changes and apoptotic blebbing in HepG2 cells. DNA fragmentation assay was used to examine later apoptosis induced by oroxylin A. FACScan analysis revealed a dramatic increase in the number of apoptotic and G 2/M phase arrest cells after oroxylin A treatment. The pro-apoptotic activity of oroxylin A was attributed to its ability to modulate the concerted expression of Bcl-2, Bax, and pro-caspase-3 proteins. The expression of Bcl-2 protein and pro-caspase-3 protein was dramatically decreased after treatment with oroxylin A. These results demonstrated that oroxylin A could effectively induce programmed cell death and suggested that it could be a promising antitumor drug.